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Diffstat (limited to '')
| -rw-r--r-- | drivers/pci/controller/pci-hyperv.c | 4068 |
1 files changed, 4068 insertions, 0 deletions
diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c new file mode 100644 index 000000000..9693bab59 --- /dev/null +++ b/drivers/pci/controller/pci-hyperv.c @@ -0,0 +1,4068 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) Microsoft Corporation. + * + * Author: + * Jake Oshins <jakeo@microsoft.com> + * + * This driver acts as a paravirtual front-end for PCI Express root buses. + * When a PCI Express function (either an entire device or an SR-IOV + * Virtual Function) is being passed through to the VM, this driver exposes + * a new bus to the guest VM. This is modeled as a root PCI bus because + * no bridges are being exposed to the VM. In fact, with a "Generation 2" + * VM within Hyper-V, there may seem to be no PCI bus at all in the VM + * until a device as been exposed using this driver. + * + * Each root PCI bus has its own PCI domain, which is called "Segment" in + * the PCI Firmware Specifications. Thus while each device passed through + * to the VM using this front-end will appear at "device 0", the domain will + * be unique. Typically, each bus will have one PCI function on it, though + * this driver does support more than one. + * + * In order to map the interrupts from the device through to the guest VM, + * this driver also implements an IRQ Domain, which handles interrupts (either + * MSI or MSI-X) associated with the functions on the bus. As interrupts are + * set up, torn down, or reaffined, this driver communicates with the + * underlying hypervisor to adjust the mappings in the I/O MMU so that each + * interrupt will be delivered to the correct virtual processor at the right + * vector. This driver does not support level-triggered (line-based) + * interrupts, and will report that the Interrupt Line register in the + * function's configuration space is zero. + * + * The rest of this driver mostly maps PCI concepts onto underlying Hyper-V + * facilities. For instance, the configuration space of a function exposed + * by Hyper-V is mapped into a single page of memory space, and the + * read and write handlers for config space must be aware of this mechanism. + * Similarly, device setup and teardown involves messages sent to and from + * the PCI back-end driver in Hyper-V. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/pci-ecam.h> +#include <linux/delay.h> +#include <linux/semaphore.h> +#include <linux/irq.h> +#include <linux/msi.h> +#include <linux/hyperv.h> +#include <linux/refcount.h> +#include <linux/irqdomain.h> +#include <linux/acpi.h> +#include <asm/mshyperv.h> + +/* + * Protocol versions. The low word is the minor version, the high word the + * major version. + */ + +#define PCI_MAKE_VERSION(major, minor) ((u32)(((major) << 16) | (minor))) +#define PCI_MAJOR_VERSION(version) ((u32)(version) >> 16) +#define PCI_MINOR_VERSION(version) ((u32)(version) & 0xff) + +enum pci_protocol_version_t { + PCI_PROTOCOL_VERSION_1_1 = PCI_MAKE_VERSION(1, 1), /* Win10 */ + PCI_PROTOCOL_VERSION_1_2 = PCI_MAKE_VERSION(1, 2), /* RS1 */ + PCI_PROTOCOL_VERSION_1_3 = PCI_MAKE_VERSION(1, 3), /* Vibranium */ + PCI_PROTOCOL_VERSION_1_4 = PCI_MAKE_VERSION(1, 4), /* WS2022 */ +}; + +#define CPU_AFFINITY_ALL -1ULL + +/* + * Supported protocol versions in the order of probing - highest go + * first. + */ +static enum pci_protocol_version_t pci_protocol_versions[] = { + PCI_PROTOCOL_VERSION_1_4, + PCI_PROTOCOL_VERSION_1_3, + PCI_PROTOCOL_VERSION_1_2, + PCI_PROTOCOL_VERSION_1_1, +}; + +#define PCI_CONFIG_MMIO_LENGTH 0x2000 +#define CFG_PAGE_OFFSET 0x1000 +#define CFG_PAGE_SIZE (PCI_CONFIG_MMIO_LENGTH - CFG_PAGE_OFFSET) + +#define MAX_SUPPORTED_MSI_MESSAGES 0x400 + +#define STATUS_REVISION_MISMATCH 0xC0000059 + +/* space for 32bit serial number as string */ +#define SLOT_NAME_SIZE 11 + +/* + * Size of requestor for VMbus; the value is based on the observation + * that having more than one request outstanding is 'rare', and so 64 + * should be generous in ensuring that we don't ever run out. + */ +#define HV_PCI_RQSTOR_SIZE 64 + +/* + * Message Types + */ + +enum pci_message_type { + /* + * Version 1.1 + */ + PCI_MESSAGE_BASE = 0x42490000, + PCI_BUS_RELATIONS = PCI_MESSAGE_BASE + 0, + PCI_QUERY_BUS_RELATIONS = PCI_MESSAGE_BASE + 1, + PCI_POWER_STATE_CHANGE = PCI_MESSAGE_BASE + 4, + PCI_QUERY_RESOURCE_REQUIREMENTS = PCI_MESSAGE_BASE + 5, + PCI_QUERY_RESOURCE_RESOURCES = PCI_MESSAGE_BASE + 6, + PCI_BUS_D0ENTRY = PCI_MESSAGE_BASE + 7, + PCI_BUS_D0EXIT = PCI_MESSAGE_BASE + 8, + PCI_READ_BLOCK = PCI_MESSAGE_BASE + 9, + PCI_WRITE_BLOCK = PCI_MESSAGE_BASE + 0xA, + PCI_EJECT = PCI_MESSAGE_BASE + 0xB, + PCI_QUERY_STOP = PCI_MESSAGE_BASE + 0xC, + PCI_REENABLE = PCI_MESSAGE_BASE + 0xD, + PCI_QUERY_STOP_FAILED = PCI_MESSAGE_BASE + 0xE, + PCI_EJECTION_COMPLETE = PCI_MESSAGE_BASE + 0xF, + PCI_RESOURCES_ASSIGNED = PCI_MESSAGE_BASE + 0x10, + PCI_RESOURCES_RELEASED = PCI_MESSAGE_BASE + 0x11, + PCI_INVALIDATE_BLOCK = PCI_MESSAGE_BASE + 0x12, + PCI_QUERY_PROTOCOL_VERSION = PCI_MESSAGE_BASE + 0x13, + PCI_CREATE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x14, + PCI_DELETE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x15, + PCI_RESOURCES_ASSIGNED2 = PCI_MESSAGE_BASE + 0x16, + PCI_CREATE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x17, + PCI_DELETE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x18, /* unused */ + PCI_BUS_RELATIONS2 = PCI_MESSAGE_BASE + 0x19, + PCI_RESOURCES_ASSIGNED3 = PCI_MESSAGE_BASE + 0x1A, + PCI_CREATE_INTERRUPT_MESSAGE3 = PCI_MESSAGE_BASE + 0x1B, + PCI_MESSAGE_MAXIMUM +}; + +/* + * Structures defining the virtual PCI Express protocol. + */ + +union pci_version { + struct { + u16 minor_version; + u16 major_version; + } parts; + u32 version; +} __packed; + +/* + * Function numbers are 8-bits wide on Express, as interpreted through ARI, + * which is all this driver does. This representation is the one used in + * Windows, which is what is expected when sending this back and forth with + * the Hyper-V parent partition. + */ +union win_slot_encoding { + struct { + u32 dev:5; + u32 func:3; + u32 reserved:24; + } bits; + u32 slot; +} __packed; + +/* + * Pretty much as defined in the PCI Specifications. + */ +struct pci_function_description { + u16 v_id; /* vendor ID */ + u16 d_id; /* device ID */ + u8 rev; + u8 prog_intf; + u8 subclass; + u8 base_class; + u32 subsystem_id; + union win_slot_encoding win_slot; + u32 ser; /* serial number */ +} __packed; + +enum pci_device_description_flags { + HV_PCI_DEVICE_FLAG_NONE = 0x0, + HV_PCI_DEVICE_FLAG_NUMA_AFFINITY = 0x1, +}; + +struct pci_function_description2 { + u16 v_id; /* vendor ID */ + u16 d_id; /* device ID */ + u8 rev; + u8 prog_intf; + u8 subclass; + u8 base_class; + u32 subsystem_id; + union win_slot_encoding win_slot; + u32 ser; /* serial number */ + u32 flags; + u16 virtual_numa_node; + u16 reserved; +} __packed; + +/** + * struct hv_msi_desc + * @vector: IDT entry + * @delivery_mode: As defined in Intel's Programmer's + * Reference Manual, Volume 3, Chapter 8. + * @vector_count: Number of contiguous entries in the + * Interrupt Descriptor Table that are + * occupied by this Message-Signaled + * Interrupt. For "MSI", as first defined + * in PCI 2.2, this can be between 1 and + * 32. For "MSI-X," as first defined in PCI + * 3.0, this must be 1, as each MSI-X table + * entry would have its own descriptor. + * @reserved: Empty space + * @cpu_mask: All the target virtual processors. + */ +struct hv_msi_desc { + u8 vector; + u8 delivery_mode; + u16 vector_count; + u32 reserved; + u64 cpu_mask; +} __packed; + +/** + * struct hv_msi_desc2 - 1.2 version of hv_msi_desc + * @vector: IDT entry + * @delivery_mode: As defined in Intel's Programmer's + * Reference Manual, Volume 3, Chapter 8. + * @vector_count: Number of contiguous entries in the + * Interrupt Descriptor Table that are + * occupied by this Message-Signaled + * Interrupt. For "MSI", as first defined + * in PCI 2.2, this can be between 1 and + * 32. For "MSI-X," as first defined in PCI + * 3.0, this must be 1, as each MSI-X table + * entry would have its own descriptor. + * @processor_count: number of bits enabled in array. + * @processor_array: All the target virtual processors. + */ +struct hv_msi_desc2 { + u8 vector; + u8 delivery_mode; + u16 vector_count; + u16 processor_count; + u16 processor_array[32]; +} __packed; + +/* + * struct hv_msi_desc3 - 1.3 version of hv_msi_desc + * Everything is the same as in 'hv_msi_desc2' except that the size of the + * 'vector' field is larger to support bigger vector values. For ex: LPI + * vectors on ARM. + */ +struct hv_msi_desc3 { + u32 vector; + u8 delivery_mode; + u8 reserved; + u16 vector_count; + u16 processor_count; + u16 processor_array[32]; +} __packed; + +/** + * struct tran_int_desc + * @reserved: unused, padding + * @vector_count: same as in hv_msi_desc + * @data: This is the "data payload" value that is + * written by the device when it generates + * a message-signaled interrupt, either MSI + * or MSI-X. + * @address: This is the address to which the data + * payload is written on interrupt + * generation. + */ +struct tran_int_desc { + u16 reserved; + u16 vector_count; + u32 data; + u64 address; +} __packed; + +/* + * A generic message format for virtual PCI. + * Specific message formats are defined later in the file. + */ + +struct pci_message { + u32 type; +} __packed; + +struct pci_child_message { + struct pci_message message_type; + union win_slot_encoding wslot; +} __packed; + +struct pci_incoming_message { + struct vmpacket_descriptor hdr; + struct pci_message message_type; +} __packed; + +struct pci_response { + struct vmpacket_descriptor hdr; + s32 status; /* negative values are failures */ +} __packed; + +struct pci_packet { + void (*completion_func)(void *context, struct pci_response *resp, + int resp_packet_size); + void *compl_ctxt; + + struct pci_message message[]; +}; + +/* + * Specific message types supporting the PCI protocol. + */ + +/* + * Version negotiation message. Sent from the guest to the host. + * The guest is free to try different versions until the host + * accepts the version. + * + * pci_version: The protocol version requested. + * is_last_attempt: If TRUE, this is the last version guest will request. + * reservedz: Reserved field, set to zero. + */ + +struct pci_version_request { + struct pci_message message_type; + u32 protocol_version; +} __packed; + +/* + * Bus D0 Entry. This is sent from the guest to the host when the virtual + * bus (PCI Express port) is ready for action. + */ + +struct pci_bus_d0_entry { + struct pci_message message_type; + u32 reserved; + u64 mmio_base; +} __packed; + +struct pci_bus_relations { + struct pci_incoming_message incoming; + u32 device_count; + struct pci_function_description func[]; +} __packed; + +struct pci_bus_relations2 { + struct pci_incoming_message incoming; + u32 device_count; + struct pci_function_description2 func[]; +} __packed; + +struct pci_q_res_req_response { + struct vmpacket_descriptor hdr; + s32 status; /* negative values are failures */ + u32 probed_bar[PCI_STD_NUM_BARS]; +} __packed; + +struct pci_set_power { + struct pci_message message_type; + union win_slot_encoding wslot; + u32 power_state; /* In Windows terms */ + u32 reserved; +} __packed; + +struct pci_set_power_response { + struct vmpacket_descriptor hdr; + s32 status; /* negative values are failures */ + union win_slot_encoding wslot; + u32 resultant_state; /* In Windows terms */ + u32 reserved; +} __packed; + +struct pci_resources_assigned { + struct pci_message message_type; + union win_slot_encoding wslot; + u8 memory_range[0x14][6]; /* not used here */ + u32 msi_descriptors; + u32 reserved[4]; +} __packed; + +struct pci_resources_assigned2 { + struct pci_message message_type; + union win_slot_encoding wslot; + u8 memory_range[0x14][6]; /* not used here */ + u32 msi_descriptor_count; + u8 reserved[70]; +} __packed; + +struct pci_create_interrupt { + struct pci_message message_type; + union win_slot_encoding wslot; + struct hv_msi_desc int_desc; +} __packed; + +struct pci_create_int_response { + struct pci_response response; + u32 reserved; + struct tran_int_desc int_desc; +} __packed; + +struct pci_create_interrupt2 { + struct pci_message message_type; + union win_slot_encoding wslot; + struct hv_msi_desc2 int_desc; +} __packed; + +struct pci_create_interrupt3 { + struct pci_message message_type; + union win_slot_encoding wslot; + struct hv_msi_desc3 int_desc; +} __packed; + +struct pci_delete_interrupt { + struct pci_message message_type; + union win_slot_encoding wslot; + struct tran_int_desc int_desc; +} __packed; + +/* + * Note: the VM must pass a valid block id, wslot and bytes_requested. + */ +struct pci_read_block { + struct pci_message message_type; + u32 block_id; + union win_slot_encoding wslot; + u32 bytes_requested; +} __packed; + +struct pci_read_block_response { + struct vmpacket_descriptor hdr; + u32 status; + u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX]; +} __packed; + +/* + * Note: the VM must pass a valid block id, wslot and byte_count. + */ +struct pci_write_block { + struct pci_message message_type; + u32 block_id; + union win_slot_encoding wslot; + u32 byte_count; + u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX]; +} __packed; + +struct pci_dev_inval_block { + struct pci_incoming_message incoming; + union win_slot_encoding wslot; + u64 block_mask; +} __packed; + +struct pci_dev_incoming { + struct pci_incoming_message incoming; + union win_slot_encoding wslot; +} __packed; + +struct pci_eject_response { + struct pci_message message_type; + union win_slot_encoding wslot; + u32 status; +} __packed; + +static int pci_ring_size = (4 * PAGE_SIZE); + +/* + * Driver specific state. + */ + +enum hv_pcibus_state { + hv_pcibus_init = 0, + hv_pcibus_probed, + hv_pcibus_installed, + hv_pcibus_removing, + hv_pcibus_maximum +}; + +struct hv_pcibus_device { +#ifdef CONFIG_X86 + struct pci_sysdata sysdata; +#elif defined(CONFIG_ARM64) + struct pci_config_window sysdata; +#endif + struct pci_host_bridge *bridge; + struct fwnode_handle *fwnode; + /* Protocol version negotiated with the host */ + enum pci_protocol_version_t protocol_version; + + struct mutex state_lock; + enum hv_pcibus_state state; + + struct hv_device *hdev; + resource_size_t low_mmio_space; + resource_size_t high_mmio_space; + struct resource *mem_config; + struct resource *low_mmio_res; + struct resource *high_mmio_res; + struct completion *survey_event; + struct pci_bus *pci_bus; + spinlock_t config_lock; /* Avoid two threads writing index page */ + spinlock_t device_list_lock; /* Protect lists below */ + void __iomem *cfg_addr; + + struct list_head children; + struct list_head dr_list; + + struct msi_domain_info msi_info; + struct irq_domain *irq_domain; + + spinlock_t retarget_msi_interrupt_lock; + + struct workqueue_struct *wq; + + /* Highest slot of child device with resources allocated */ + int wslot_res_allocated; + + /* hypercall arg, must not cross page boundary */ + struct hv_retarget_device_interrupt retarget_msi_interrupt_params; + + /* + * Don't put anything here: retarget_msi_interrupt_params must be last + */ +}; + +/* + * Tracks "Device Relations" messages from the host, which must be both + * processed in order and deferred so that they don't run in the context + * of the incoming packet callback. + */ +struct hv_dr_work { + struct work_struct wrk; + struct hv_pcibus_device *bus; +}; + +struct hv_pcidev_description { + u16 v_id; /* vendor ID */ + u16 d_id; /* device ID */ + u8 rev; + u8 prog_intf; + u8 subclass; + u8 base_class; + u32 subsystem_id; + union win_slot_encoding win_slot; + u32 ser; /* serial number */ + u32 flags; + u16 virtual_numa_node; +}; + +struct hv_dr_state { + struct list_head list_entry; + u32 device_count; + struct hv_pcidev_description func[]; +}; + +struct hv_pci_dev { + /* List protected by pci_rescan_remove_lock */ + struct list_head list_entry; + refcount_t refs; + struct pci_slot *pci_slot; + struct hv_pcidev_description desc; + bool reported_missing; + struct hv_pcibus_device *hbus; + struct work_struct wrk; + + void (*block_invalidate)(void *context, u64 block_mask); + void *invalidate_context; + + /* + * What would be observed if one wrote 0xFFFFFFFF to a BAR and then + * read it back, for each of the BAR offsets within config space. + */ + u32 probed_bar[PCI_STD_NUM_BARS]; +}; + +struct hv_pci_compl { + struct completion host_event; + s32 completion_status; +}; + +static void hv_pci_onchannelcallback(void *context); + +#ifdef CONFIG_X86 +#define DELIVERY_MODE APIC_DELIVERY_MODE_FIXED +#define FLOW_HANDLER handle_edge_irq +#define FLOW_NAME "edge" + +static int hv_pci_irqchip_init(void) +{ + return 0; +} + +static struct irq_domain *hv_pci_get_root_domain(void) +{ + return x86_vector_domain; +} + +static unsigned int hv_msi_get_int_vector(struct irq_data *data) +{ + struct irq_cfg *cfg = irqd_cfg(data); + + return cfg->vector; +} + +static int hv_msi_prepare(struct irq_domain *domain, struct device *dev, + int nvec, msi_alloc_info_t *info) +{ + int ret = pci_msi_prepare(domain, dev, nvec, info); + + /* + * By using the interrupt remapper in the hypervisor IOMMU, contiguous + * CPU vectors is not needed for multi-MSI + */ + if (info->type == X86_IRQ_ALLOC_TYPE_PCI_MSI) + info->flags &= ~X86_IRQ_ALLOC_CONTIGUOUS_VECTORS; + + return ret; +} + +/** + * hv_arch_irq_unmask() - "Unmask" the IRQ by setting its current + * affinity. + * @data: Describes the IRQ + * + * Build new a destination for the MSI and make a hypercall to + * update the Interrupt Redirection Table. "Device Logical ID" + * is built out of this PCI bus's instance GUID and the function + * number of the device. + */ +static void hv_arch_irq_unmask(struct irq_data *data) +{ + struct msi_desc *msi_desc = irq_data_get_msi_desc(data); + struct hv_retarget_device_interrupt *params; + struct tran_int_desc *int_desc; + struct hv_pcibus_device *hbus; + const struct cpumask *dest; + cpumask_var_t tmp; + struct pci_bus *pbus; + struct pci_dev *pdev; + unsigned long flags; + u32 var_size = 0; + int cpu, nr_bank; + u64 res; + + dest = irq_data_get_effective_affinity_mask(data); + pdev = msi_desc_to_pci_dev(msi_desc); + pbus = pdev->bus; + hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata); + int_desc = data->chip_data; + if (!int_desc) { + dev_warn(&hbus->hdev->device, "%s() can not unmask irq %u\n", + __func__, data->irq); + return; + } + + spin_lock_irqsave(&hbus->retarget_msi_interrupt_lock, flags); + + params = &hbus->retarget_msi_interrupt_params; + memset(params, 0, sizeof(*params)); + params->partition_id = HV_PARTITION_ID_SELF; + params->int_entry.source = HV_INTERRUPT_SOURCE_MSI; + params->int_entry.msi_entry.address.as_uint32 = int_desc->address & 0xffffffff; + params->int_entry.msi_entry.data.as_uint32 = int_desc->data; + params->device_id = (hbus->hdev->dev_instance.b[5] << 24) | + (hbus->hdev->dev_instance.b[4] << 16) | + (hbus->hdev->dev_instance.b[7] << 8) | + (hbus->hdev->dev_instance.b[6] & 0xf8) | + PCI_FUNC(pdev->devfn); + params->int_target.vector = hv_msi_get_int_vector(data); + + /* + * Honoring apic->delivery_mode set to APIC_DELIVERY_MODE_FIXED by + * setting the HV_DEVICE_INTERRUPT_TARGET_MULTICAST flag results in a + * spurious interrupt storm. Not doing so does not seem to have a + * negative effect (yet?). + */ + + if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) { + /* + * PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the + * HVCALL_RETARGET_INTERRUPT hypercall, which also coincides + * with >64 VP support. + * ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED + * is not sufficient for this hypercall. + */ + params->int_target.flags |= + HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET; + + if (!alloc_cpumask_var(&tmp, GFP_ATOMIC)) { + res = 1; + goto exit_unlock; + } + + cpumask_and(tmp, dest, cpu_online_mask); + nr_bank = cpumask_to_vpset(¶ms->int_target.vp_set, tmp); + free_cpumask_var(tmp); + + if (nr_bank <= 0) { + res = 1; + goto exit_unlock; + } + + /* + * var-sized hypercall, var-size starts after vp_mask (thus + * vp_set.format does not count, but vp_set.valid_bank_mask + * does). + */ + var_size = 1 + nr_bank; + } else { + for_each_cpu_and(cpu, dest, cpu_online_mask) { + params->int_target.vp_mask |= + (1ULL << hv_cpu_number_to_vp_number(cpu)); + } + } + + res = hv_do_hypercall(HVCALL_RETARGET_INTERRUPT | (var_size << 17), + params, NULL); + +exit_unlock: + spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags); + + /* + * During hibernation, when a CPU is offlined, the kernel tries + * to move the interrupt to the remaining CPUs that haven't + * been offlined yet. In this case, the below hv_do_hypercall() + * always fails since the vmbus channel has been closed: + * refer to cpu_disable_common() -> fixup_irqs() -> + * irq_migrate_all_off_this_cpu() -> migrate_one_irq(). + * + * Suppress the error message for hibernation because the failure + * during hibernation does not matter (at this time all the devices + * have been frozen). Note: the correct affinity info is still updated + * into the irqdata data structure in migrate_one_irq() -> + * irq_do_set_affinity() -> hv_set_affinity(), so later when the VM + * resumes, hv_pci_restore_msi_state() is able to correctly restore + * the interrupt with the correct affinity. + */ + if (!hv_result_success(res) && hbus->state != hv_pcibus_removing) + dev_err(&hbus->hdev->device, + "%s() failed: %#llx", __func__, res); +} +#elif defined(CONFIG_ARM64) +/* + * SPI vectors to use for vPCI; arch SPIs range is [32, 1019], but leaving a bit + * of room at the start to allow for SPIs to be specified through ACPI and + * starting with a power of two to satisfy power of 2 multi-MSI requirement. + */ +#define HV_PCI_MSI_SPI_START 64 +#define HV_PCI_MSI_SPI_NR (1020 - HV_PCI_MSI_SPI_START) +#define DELIVERY_MODE 0 +#define FLOW_HANDLER NULL +#define FLOW_NAME NULL +#define hv_msi_prepare NULL + +struct hv_pci_chip_data { + DECLARE_BITMAP(spi_map, HV_PCI_MSI_SPI_NR); + struct mutex map_lock; +}; + +/* Hyper-V vPCI MSI GIC IRQ domain */ +static struct irq_domain *hv_msi_gic_irq_domain; + +/* Hyper-V PCI MSI IRQ chip */ +static struct irq_chip hv_arm64_msi_irq_chip = { + .name = "MSI", + .irq_set_affinity = irq_chip_set_affinity_parent, + .irq_eoi = irq_chip_eoi_parent, + .irq_mask = irq_chip_mask_parent, + .irq_unmask = irq_chip_unmask_parent +}; + +static unsigned int hv_msi_get_int_vector(struct irq_data *irqd) +{ + return irqd->parent_data->hwirq; +} + +/* + * @nr_bm_irqs: Indicates the number of IRQs that were allocated from + * the bitmap. + * @nr_dom_irqs: Indicates the number of IRQs that were allocated from + * the parent domain. + */ +static void hv_pci_vec_irq_free(struct irq_domain *domain, + unsigned int virq, + unsigned int nr_bm_irqs, + unsigned int nr_dom_irqs) +{ + struct hv_pci_chip_data *chip_data = domain->host_data; + struct irq_data *d = irq_domain_get_irq_data(domain, virq); + int first = d->hwirq - HV_PCI_MSI_SPI_START; + int i; + + mutex_lock(&chip_data->map_lock); + bitmap_release_region(chip_data->spi_map, + first, + get_count_order(nr_bm_irqs)); + mutex_unlock(&chip_data->map_lock); + for (i = 0; i < nr_dom_irqs; i++) { + if (i) + d = irq_domain_get_irq_data(domain, virq + i); + irq_domain_reset_irq_data(d); + } + + irq_domain_free_irqs_parent(domain, virq, nr_dom_irqs); +} + +static void hv_pci_vec_irq_domain_free(struct irq_domain *domain, + unsigned int virq, + unsigned int nr_irqs) +{ + hv_pci_vec_irq_free(domain, virq, nr_irqs, nr_irqs); +} + +static int hv_pci_vec_alloc_device_irq(struct irq_domain *domain, + unsigned int nr_irqs, + irq_hw_number_t *hwirq) +{ + struct hv_pci_chip_data *chip_data = domain->host_data; + int index; + + /* Find and allocate region from the SPI bitmap */ + mutex_lock(&chip_data->map_lock); + index = bitmap_find_free_region(chip_data->spi_map, + HV_PCI_MSI_SPI_NR, + get_count_order(nr_irqs)); + mutex_unlock(&chip_data->map_lock); + if (index < 0) + return -ENOSPC; + + *hwirq = index + HV_PCI_MSI_SPI_START; + + return 0; +} + +static int hv_pci_vec_irq_gic_domain_alloc(struct irq_domain *domain, + unsigned int virq, + irq_hw_number_t hwirq) +{ + struct irq_fwspec fwspec; + struct irq_data *d; + int ret; + + fwspec.fwnode = domain->parent->fwnode; + fwspec.param_count = 2; + fwspec.param[0] = hwirq; + fwspec.param[1] = IRQ_TYPE_EDGE_RISING; + + ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec); + if (ret) + return ret; + + /* + * Since the interrupt specifier is not coming from ACPI or DT, the + * trigger type will need to be set explicitly. Otherwise, it will be + * set to whatever is in the GIC configuration. + */ + d = irq_domain_get_irq_data(domain->parent, virq); + + return d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING); +} + +static int hv_pci_vec_irq_domain_alloc(struct irq_domain *domain, + unsigned int virq, unsigned int nr_irqs, + void *args) +{ + irq_hw_number_t hwirq; + unsigned int i; + int ret; + + ret = hv_pci_vec_alloc_device_irq(domain, nr_irqs, &hwirq); + if (ret) + return ret; + + for (i = 0; i < nr_irqs; i++) { + ret = hv_pci_vec_irq_gic_domain_alloc(domain, virq + i, + hwirq + i); + if (ret) { + hv_pci_vec_irq_free(domain, virq, nr_irqs, i); + return ret; + } + + irq_domain_set_hwirq_and_chip(domain, virq + i, + hwirq + i, + &hv_arm64_msi_irq_chip, + domain->host_data); + pr_debug("pID:%d vID:%u\n", (int)(hwirq + i), virq + i); + } + + return 0; +} + +/* + * Pick the first cpu as the irq affinity that can be temporarily used for + * composing MSI from the hypervisor. GIC will eventually set the right + * affinity for the irq and the 'unmask' will retarget the interrupt to that + * cpu. + */ +static int hv_pci_vec_irq_domain_activate(struct irq_domain *domain, + struct irq_data *irqd, bool reserve) +{ + int cpu = cpumask_first(cpu_present_mask); + + irq_data_update_effective_affinity(irqd, cpumask_of(cpu)); + + return 0; +} + +static const struct irq_domain_ops hv_pci_domain_ops = { + .alloc = hv_pci_vec_irq_domain_alloc, + .free = hv_pci_vec_irq_domain_free, + .activate = hv_pci_vec_irq_domain_activate, +}; + +static int hv_pci_irqchip_init(void) +{ + static struct hv_pci_chip_data *chip_data; + struct fwnode_handle *fn = NULL; + int ret = -ENOMEM; + + chip_data = kzalloc(sizeof(*chip_data), GFP_KERNEL); + if (!chip_data) + return ret; + + mutex_init(&chip_data->map_lock); + fn = irq_domain_alloc_named_fwnode("hv_vpci_arm64"); + if (!fn) + goto free_chip; + + /* + * IRQ domain once enabled, should not be removed since there is no + * way to ensure that all the corresponding devices are also gone and + * no interrupts will be generated. + */ + hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR, + fn, &hv_pci_domain_ops, + chip_data); + + if (!hv_msi_gic_irq_domain) { + pr_err("Failed to create Hyper-V arm64 vPCI MSI IRQ domain\n"); + goto free_chip; + } + + return 0; + +free_chip: + kfree(chip_data); + if (fn) + irq_domain_free_fwnode(fn); + + return ret; +} + +static struct irq_domain *hv_pci_get_root_domain(void) +{ + return hv_msi_gic_irq_domain; +} + +/* + * SPIs are used for interrupts of PCI devices and SPIs is managed via GICD + * registers which Hyper-V already supports, so no hypercall needed. + */ +static void hv_arch_irq_unmask(struct irq_data *data) { } +#endif /* CONFIG_ARM64 */ + +/** + * hv_pci_generic_compl() - Invoked for a completion packet + * @context: Set up by the sender of the packet. + * @resp: The response packet + * @resp_packet_size: Size in bytes of the packet + * + * This function is used to trigger an event and report status + * for any message for which the completion packet contains a + * status and nothing else. + */ +static void hv_pci_generic_compl(void *context, struct pci_response *resp, + int resp_packet_size) +{ + struct hv_pci_compl *comp_pkt = context; + + comp_pkt->completion_status = resp->status; + complete(&comp_pkt->host_event); +} + +static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus, + u32 wslot); + +static void get_pcichild(struct hv_pci_dev *hpdev) +{ + refcount_inc(&hpdev->refs); +} + +static void put_pcichild(struct hv_pci_dev *hpdev) +{ + if (refcount_dec_and_test(&hpdev->refs)) + kfree(hpdev); +} + +/* + * There is no good way to get notified from vmbus_onoffer_rescind(), + * so let's use polling here, since this is not a hot path. + */ +static int wait_for_response(struct hv_device *hdev, + struct completion *comp) +{ + while (true) { + if (hdev->channel->rescind) { + dev_warn_once(&hdev->device, "The device is gone.\n"); + return -ENODEV; + } + + if (wait_for_completion_timeout(comp, HZ / 10)) + break; + } + + return 0; +} + +/** + * devfn_to_wslot() - Convert from Linux PCI slot to Windows + * @devfn: The Linux representation of PCI slot + * + * Windows uses a slightly different representation of PCI slot. + * + * Return: The Windows representation + */ +static u32 devfn_to_wslot(int devfn) +{ + union win_slot_encoding wslot; + + wslot.slot = 0; + wslot.bits.dev = PCI_SLOT(devfn); + wslot.bits.func = PCI_FUNC(devfn); + + return wslot.slot; +} + +/** + * wslot_to_devfn() - Convert from Windows PCI slot to Linux + * @wslot: The Windows representation of PCI slot + * + * Windows uses a slightly different representation of PCI slot. + * + * Return: The Linux representation + */ +static int wslot_to_devfn(u32 wslot) +{ + union win_slot_encoding slot_no; + + slot_no.slot = wslot; + return PCI_DEVFN(slot_no.bits.dev, slot_no.bits.func); +} + +/* + * PCI Configuration Space for these root PCI buses is implemented as a pair + * of pages in memory-mapped I/O space. Writing to the first page chooses + * the PCI function being written or read. Once the first page has been + * written to, the following page maps in the entire configuration space of + * the function. + */ + +/** + * _hv_pcifront_read_config() - Internal PCI config read + * @hpdev: The PCI driver's representation of the device + * @where: Offset within config space + * @size: Size of the transfer + * @val: Pointer to the buffer receiving the data + */ +static void _hv_pcifront_read_config(struct hv_pci_dev *hpdev, int where, + int size, u32 *val) +{ + unsigned long flags; + void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where; + + /* + * If the attempt is to read the IDs or the ROM BAR, simulate that. + */ + if (where + size <= PCI_COMMAND) { + memcpy(val, ((u8 *)&hpdev->desc.v_id) + where, size); + } else if (where >= PCI_CLASS_REVISION && where + size <= + PCI_CACHE_LINE_SIZE) { + memcpy(val, ((u8 *)&hpdev->desc.rev) + where - + PCI_CLASS_REVISION, size); + } else if (where >= PCI_SUBSYSTEM_VENDOR_ID && where + size <= + PCI_ROM_ADDRESS) { + memcpy(val, (u8 *)&hpdev->desc.subsystem_id + where - + PCI_SUBSYSTEM_VENDOR_ID, size); + } else if (where >= PCI_ROM_ADDRESS && where + size <= + PCI_CAPABILITY_LIST) { + /* ROM BARs are unimplemented */ + *val = 0; + } else if (where >= PCI_INTERRUPT_LINE && where + size <= + PCI_INTERRUPT_PIN) { + /* + * Interrupt Line and Interrupt PIN are hard-wired to zero + * because this front-end only supports message-signaled + * interrupts. + */ + *val = 0; + } else if (where + size <= CFG_PAGE_SIZE) { + spin_lock_irqsave(&hpdev->hbus->config_lock, flags); + /* Choose the function to be read. (See comment above) */ + writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr); + /* Make sure the function was chosen before we start reading. */ + mb(); + /* Read from that function's config space. */ + switch (size) { + case 1: + *val = readb(addr); + break; + case 2: + *val = readw(addr); + break; + default: + *val = readl(addr); + break; + } + /* + * Make sure the read was done before we release the spinlock + * allowing consecutive reads/writes. + */ + mb(); + spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags); + } else { + dev_err(&hpdev->hbus->hdev->device, + "Attempt to read beyond a function's config space.\n"); + } +} + +static u16 hv_pcifront_get_vendor_id(struct hv_pci_dev *hpdev) +{ + u16 ret; + unsigned long flags; + void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + + PCI_VENDOR_ID; + + spin_lock_irqsave(&hpdev->hbus->config_lock, flags); + + /* Choose the function to be read. (See comment above) */ + writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr); + /* Make sure the function was chosen before we start reading. */ + mb(); + /* Read from that function's config space. */ + ret = readw(addr); + /* + * mb() is not required here, because the spin_unlock_irqrestore() + * is a barrier. + */ + + spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags); + + return ret; +} + +/** + * _hv_pcifront_write_config() - Internal PCI config write + * @hpdev: The PCI driver's representation of the device + * @where: Offset within config space + * @size: Size of the transfer + * @val: The data being transferred + */ +static void _hv_pcifront_write_config(struct hv_pci_dev *hpdev, int where, + int size, u32 val) +{ + unsigned long flags; + void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where; + + if (where >= PCI_SUBSYSTEM_VENDOR_ID && + where + size <= PCI_CAPABILITY_LIST) { + /* SSIDs and ROM BARs are read-only */ + } else if (where >= PCI_COMMAND && where + size <= CFG_PAGE_SIZE) { + spin_lock_irqsave(&hpdev->hbus->config_lock, flags); + /* Choose the function to be written. (See comment above) */ + writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr); + /* Make sure the function was chosen before we start writing. */ + wmb(); + /* Write to that function's config space. */ + switch (size) { + case 1: + writeb(val, addr); + break; + case 2: + writew(val, addr); + break; + default: + writel(val, addr); + break; + } + /* + * Make sure the write was done before we release the spinlock + * allowing consecutive reads/writes. + */ + mb(); + spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags); + } else { + dev_err(&hpdev->hbus->hdev->device, + "Attempt to write beyond a function's config space.\n"); + } +} + +/** + * hv_pcifront_read_config() - Read configuration space + * @bus: PCI Bus structure + * @devfn: Device/function + * @where: Offset from base + * @size: Byte/word/dword + * @val: Value to be read + * + * Return: PCIBIOS_SUCCESSFUL on success + * PCIBIOS_DEVICE_NOT_FOUND on failure + */ +static int hv_pcifront_read_config(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *val) +{ + struct hv_pcibus_device *hbus = + container_of(bus->sysdata, struct hv_pcibus_device, sysdata); + struct hv_pci_dev *hpdev; + + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn)); + if (!hpdev) + return PCIBIOS_DEVICE_NOT_FOUND; + + _hv_pcifront_read_config(hpdev, where, size, val); + + put_pcichild(hpdev); + return PCIBIOS_SUCCESSFUL; +} + +/** + * hv_pcifront_write_config() - Write configuration space + * @bus: PCI Bus structure + * @devfn: Device/function + * @where: Offset from base + * @size: Byte/word/dword + * @val: Value to be written to device + * + * Return: PCIBIOS_SUCCESSFUL on success + * PCIBIOS_DEVICE_NOT_FOUND on failure + */ +static int hv_pcifront_write_config(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 val) +{ + struct hv_pcibus_device *hbus = + container_of(bus->sysdata, struct hv_pcibus_device, sysdata); + struct hv_pci_dev *hpdev; + + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn)); + if (!hpdev) + return PCIBIOS_DEVICE_NOT_FOUND; + + _hv_pcifront_write_config(hpdev, where, size, val); + + put_pcichild(hpdev); + return PCIBIOS_SUCCESSFUL; +} + +/* PCIe operations */ +static struct pci_ops hv_pcifront_ops = { + .read = hv_pcifront_read_config, + .write = hv_pcifront_write_config, +}; + +/* + * Paravirtual backchannel + * + * Hyper-V SR-IOV provides a backchannel mechanism in software for + * communication between a VF driver and a PF driver. These + * "configuration blocks" are similar in concept to PCI configuration space, + * but instead of doing reads and writes in 32-bit chunks through a very slow + * path, packets of up to 128 bytes can be sent or received asynchronously. + * + * Nearly every SR-IOV device contains just such a communications channel in + * hardware, so using this one in software is usually optional. Using the + * software channel, however, allows driver implementers to leverage software + * tools that fuzz the communications channel looking for vulnerabilities. + * + * The usage model for these packets puts the responsibility for reading or + * writing on the VF driver. The VF driver sends a read or a write packet, + * indicating which "block" is being referred to by number. + * + * If the PF driver wishes to initiate communication, it can "invalidate" one or + * more of the first 64 blocks. This invalidation is delivered via a callback + * supplied by the VF driver by this driver. + * + * No protocol is implied, except that supplied by the PF and VF drivers. + */ + +struct hv_read_config_compl { + struct hv_pci_compl comp_pkt; + void *buf; + unsigned int len; + unsigned int bytes_returned; +}; + +/** + * hv_pci_read_config_compl() - Invoked when a response packet + * for a read config block operation arrives. + * @context: Identifies the read config operation + * @resp: The response packet itself + * @resp_packet_size: Size in bytes of the response packet + */ +static void hv_pci_read_config_compl(void *context, struct pci_response *resp, + int resp_packet_size) +{ + struct hv_read_config_compl *comp = context; + struct pci_read_block_response *read_resp = + (struct pci_read_block_response *)resp; + unsigned int data_len, hdr_len; + + hdr_len = offsetof(struct pci_read_block_response, bytes); + if (resp_packet_size < hdr_len) { + comp->comp_pkt.completion_status = -1; + goto out; + } + + data_len = resp_packet_size - hdr_len; + if (data_len > 0 && read_resp->status == 0) { + comp->bytes_returned = min(comp->len, data_len); + memcpy(comp->buf, read_resp->bytes, comp->bytes_returned); + } else { + comp->bytes_returned = 0; + } + + comp->comp_pkt.completion_status = read_resp->status; +out: + complete(&comp->comp_pkt.host_event); +} + +/** + * hv_read_config_block() - Sends a read config block request to + * the back-end driver running in the Hyper-V parent partition. + * @pdev: The PCI driver's representation for this device. + * @buf: Buffer into which the config block will be copied. + * @len: Size in bytes of buf. + * @block_id: Identifies the config block which has been requested. + * @bytes_returned: Size which came back from the back-end driver. + * + * Return: 0 on success, -errno on failure + */ +static int hv_read_config_block(struct pci_dev *pdev, void *buf, + unsigned int len, unsigned int block_id, + unsigned int *bytes_returned) +{ + struct hv_pcibus_device *hbus = + container_of(pdev->bus->sysdata, struct hv_pcibus_device, + sysdata); + struct { + struct pci_packet pkt; + char buf[sizeof(struct pci_read_block)]; + } pkt; + struct hv_read_config_compl comp_pkt; + struct pci_read_block *read_blk; + int ret; + + if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX) + return -EINVAL; + + init_completion(&comp_pkt.comp_pkt.host_event); + comp_pkt.buf = buf; + comp_pkt.len = len; + + memset(&pkt, 0, sizeof(pkt)); + pkt.pkt.completion_func = hv_pci_read_config_compl; + pkt.pkt.compl_ctxt = &comp_pkt; + read_blk = (struct pci_read_block *)&pkt.pkt.message; + read_blk->message_type.type = PCI_READ_BLOCK; + read_blk->wslot.slot = devfn_to_wslot(pdev->devfn); + read_blk->block_id = block_id; + read_blk->bytes_requested = len; + + ret = vmbus_sendpacket(hbus->hdev->channel, read_blk, + sizeof(*read_blk), (unsigned long)&pkt.pkt, + VM_PKT_DATA_INBAND, + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); + if (ret) + return ret; + + ret = wait_for_response(hbus->hdev, &comp_pkt.comp_pkt.host_event); + if (ret) + return ret; + + if (comp_pkt.comp_pkt.completion_status != 0 || + comp_pkt.bytes_returned == 0) { + dev_err(&hbus->hdev->device, + "Read Config Block failed: 0x%x, bytes_returned=%d\n", + comp_pkt.comp_pkt.completion_status, + comp_pkt.bytes_returned); + return -EIO; + } + + *bytes_returned = comp_pkt.bytes_returned; + return 0; +} + +/** + * hv_pci_write_config_compl() - Invoked when a response packet for a write + * config block operation arrives. + * @context: Identifies the write config operation + * @resp: The response packet itself + * @resp_packet_size: Size in bytes of the response packet + */ +static void hv_pci_write_config_compl(void *context, struct pci_response *resp, + int resp_packet_size) +{ + struct hv_pci_compl *comp_pkt = context; + + comp_pkt->completion_status = resp->status; + complete(&comp_pkt->host_event); +} + +/** + * hv_write_config_block() - Sends a write config block request to the + * back-end driver running in the Hyper-V parent partition. + * @pdev: The PCI driver's representation for this device. + * @buf: Buffer from which the config block will be copied. + * @len: Size in bytes of buf. + * @block_id: Identifies the config block which is being written. + * + * Return: 0 on success, -errno on failure + */ +static int hv_write_config_block(struct pci_dev *pdev, void *buf, + unsigned int len, unsigned int block_id) +{ + struct hv_pcibus_device *hbus = + container_of(pdev->bus->sysdata, struct hv_pcibus_device, + sysdata); + struct { + struct pci_packet pkt; + char buf[sizeof(struct pci_write_block)]; + u32 reserved; + } pkt; + struct hv_pci_compl comp_pkt; + struct pci_write_block *write_blk; + u32 pkt_size; + int ret; + + if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX) + return -EINVAL; + + init_completion(&comp_pkt.host_event); + + memset(&pkt, 0, sizeof(pkt)); + pkt.pkt.completion_func = hv_pci_write_config_compl; + pkt.pkt.compl_ctxt = &comp_pkt; + write_blk = (struct pci_write_block *)&pkt.pkt.message; + write_blk->message_type.type = PCI_WRITE_BLOCK; + write_blk->wslot.slot = devfn_to_wslot(pdev->devfn); + write_blk->block_id = block_id; + write_blk->byte_count = len; + memcpy(write_blk->bytes, buf, len); + pkt_size = offsetof(struct pci_write_block, bytes) + len; + /* + * This quirk is required on some hosts shipped around 2018, because + * these hosts don't check the pkt_size correctly (new hosts have been + * fixed since early 2019). The quirk is also safe on very old hosts + * and new hosts, because, on them, what really matters is the length + * specified in write_blk->byte_count. + */ + pkt_size += sizeof(pkt.reserved); + + ret = vmbus_sendpacket(hbus->hdev->channel, write_blk, pkt_size, + (unsigned long)&pkt.pkt, VM_PKT_DATA_INBAND, + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); + if (ret) + return ret; + + ret = wait_for_response(hbus->hdev, &comp_pkt.host_event); + if (ret) + return ret; + + if (comp_pkt.completion_status != 0) { + dev_err(&hbus->hdev->device, + "Write Config Block failed: 0x%x\n", + comp_pkt.completion_status); + return -EIO; + } + + return 0; +} + +/** + * hv_register_block_invalidate() - Invoked when a config block invalidation + * arrives from the back-end driver. + * @pdev: The PCI driver's representation for this device. + * @context: Identifies the device. + * @block_invalidate: Identifies all of the blocks being invalidated. + * + * Return: 0 on success, -errno on failure + */ +static int hv_register_block_invalidate(struct pci_dev *pdev, void *context, + void (*block_invalidate)(void *context, + u64 block_mask)) +{ + struct hv_pcibus_device *hbus = + container_of(pdev->bus->sysdata, struct hv_pcibus_device, + sysdata); + struct hv_pci_dev *hpdev; + + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn)); + if (!hpdev) + return -ENODEV; + + hpdev->block_invalidate = block_invalidate; + hpdev->invalidate_context = context; + + put_pcichild(hpdev); + return 0; + +} + +/* Interrupt management hooks */ +static void hv_int_desc_free(struct hv_pci_dev *hpdev, + struct tran_int_desc *int_desc) +{ + struct pci_delete_interrupt *int_pkt; + struct { + struct pci_packet pkt; + u8 buffer[sizeof(struct pci_delete_interrupt)]; + } ctxt; + + if (!int_desc->vector_count) { + kfree(int_desc); + return; + } + memset(&ctxt, 0, sizeof(ctxt)); + int_pkt = (struct pci_delete_interrupt *)&ctxt.pkt.message; + int_pkt->message_type.type = + PCI_DELETE_INTERRUPT_MESSAGE; + int_pkt->wslot.slot = hpdev->desc.win_slot.slot; + int_pkt->int_desc = *int_desc; + vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt, sizeof(*int_pkt), + 0, VM_PKT_DATA_INBAND, 0); + kfree(int_desc); +} + +/** + * hv_msi_free() - Free the MSI. + * @domain: The interrupt domain pointer + * @info: Extra MSI-related context + * @irq: Identifies the IRQ. + * + * The Hyper-V parent partition and hypervisor are tracking the + * messages that are in use, keeping the interrupt redirection + * table up to date. This callback sends a message that frees + * the IRT entry and related tracking nonsense. + */ +static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info, + unsigned int irq) +{ + struct hv_pcibus_device *hbus; + struct hv_pci_dev *hpdev; + struct pci_dev *pdev; + struct tran_int_desc *int_desc; + struct irq_data *irq_data = irq_domain_get_irq_data(domain, irq); + struct msi_desc *msi = irq_data_get_msi_desc(irq_data); + + pdev = msi_desc_to_pci_dev(msi); + hbus = info->data; + int_desc = irq_data_get_irq_chip_data(irq_data); + if (!int_desc) + return; + + irq_data->chip_data = NULL; + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn)); + if (!hpdev) { + kfree(int_desc); + return; + } + + hv_int_desc_free(hpdev, int_desc); + put_pcichild(hpdev); +} + +static void hv_irq_mask(struct irq_data *data) +{ + pci_msi_mask_irq(data); + if (data->parent_data->chip->irq_mask) + irq_chip_mask_parent(data); +} + +static void hv_irq_unmask(struct irq_data *data) +{ + hv_arch_irq_unmask(data); + + if (data->parent_data->chip->irq_unmask) + irq_chip_unmask_parent(data); + pci_msi_unmask_irq(data); +} + +struct compose_comp_ctxt { + struct hv_pci_compl comp_pkt; + struct tran_int_desc int_desc; +}; + +static void hv_pci_compose_compl(void *context, struct pci_response *resp, + int resp_packet_size) +{ + struct compose_comp_ctxt *comp_pkt = context; + struct pci_create_int_response *int_resp = + (struct pci_create_int_response *)resp; + + if (resp_packet_size < sizeof(*int_resp)) { + comp_pkt->comp_pkt.completion_status = -1; + goto out; + } + comp_pkt->comp_pkt.completion_status = resp->status; + comp_pkt->int_desc = int_resp->int_desc; +out: + complete(&comp_pkt->comp_pkt.host_event); +} + +static u32 hv_compose_msi_req_v1( + struct pci_create_interrupt *int_pkt, + u32 slot, u8 vector, u16 vector_count) +{ + int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE; + int_pkt->wslot.slot = slot; + int_pkt->int_desc.vector = vector; + int_pkt->int_desc.vector_count = vector_count; + int_pkt->int_desc.delivery_mode = DELIVERY_MODE; + + /* + * Create MSI w/ dummy vCPU set, overwritten by subsequent retarget in + * hv_irq_unmask(). + */ + int_pkt->int_desc.cpu_mask = CPU_AFFINITY_ALL; + + return sizeof(*int_pkt); +} + +/* + * The vCPU selected by hv_compose_multi_msi_req_get_cpu() and + * hv_compose_msi_req_get_cpu() is a "dummy" vCPU because the final vCPU to be + * interrupted is specified later in hv_irq_unmask() and communicated to Hyper-V + * via the HVCALL_RETARGET_INTERRUPT hypercall. But the choice of dummy vCPU is + * not irrelevant because Hyper-V chooses the physical CPU to handle the + * interrupts based on the vCPU specified in message sent to the vPCI VSP in + * hv_compose_msi_msg(). Hyper-V's choice of pCPU is not visible to the guest, + * but assigning too many vPCI device interrupts to the same pCPU can cause a + * performance bottleneck. So we spread out the dummy vCPUs to influence Hyper-V + * to spread out the pCPUs that it selects. + * + * For the single-MSI and MSI-X cases, it's OK for hv_compose_msi_req_get_cpu() + * to always return the same dummy vCPU, because a second call to + * hv_compose_msi_msg() contains the "real" vCPU, causing Hyper-V to choose a + * new pCPU for the interrupt. But for the multi-MSI case, the second call to + * hv_compose_msi_msg() exits without sending a message to the vPCI VSP, so the + * original dummy vCPU is used. This dummy vCPU must be round-robin'ed so that + * the pCPUs are spread out. All interrupts for a multi-MSI device end up using + * the same pCPU, even though the vCPUs will be spread out by later calls + * to hv_irq_unmask(), but that is the best we can do now. + * + * With Hyper-V in Nov 2022, the HVCALL_RETARGET_INTERRUPT hypercall does *not* + * cause Hyper-V to reselect the pCPU based on the specified vCPU. Such an + * enhancement is planned for a future version. With that enhancement, the + * dummy vCPU selection won't matter, and interrupts for the same multi-MSI + * device will be spread across multiple pCPUs. + */ + +/* + * Create MSI w/ dummy vCPU set targeting just one vCPU, overwritten + * by subsequent retarget in hv_irq_unmask(). + */ +static int hv_compose_msi_req_get_cpu(const struct cpumask *affinity) +{ + return cpumask_first_and(affinity, cpu_online_mask); +} + +/* + * Make sure the dummy vCPU values for multi-MSI don't all point to vCPU0. + */ +static int hv_compose_multi_msi_req_get_cpu(void) +{ + static DEFINE_SPINLOCK(multi_msi_cpu_lock); + + /* -1 means starting with CPU 0 */ + static int cpu_next = -1; + + unsigned long flags; + int cpu; + + spin_lock_irqsave(&multi_msi_cpu_lock, flags); + + cpu_next = cpumask_next_wrap(cpu_next, cpu_online_mask, nr_cpu_ids, + false); + cpu = cpu_next; + + spin_unlock_irqrestore(&multi_msi_cpu_lock, flags); + + return cpu; +} + +static u32 hv_compose_msi_req_v2( + struct pci_create_interrupt2 *int_pkt, int cpu, + u32 slot, u8 vector, u16 vector_count) +{ + int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE2; + int_pkt->wslot.slot = slot; + int_pkt->int_desc.vector = vector; + int_pkt->int_desc.vector_count = vector_count; + int_pkt->int_desc.delivery_mode = DELIVERY_MODE; + int_pkt->int_desc.processor_array[0] = + hv_cpu_number_to_vp_number(cpu); + int_pkt->int_desc.processor_count = 1; + + return sizeof(*int_pkt); +} + +static u32 hv_compose_msi_req_v3( + struct pci_create_interrupt3 *int_pkt, int cpu, + u32 slot, u32 vector, u16 vector_count) +{ + int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE3; + int_pkt->wslot.slot = slot; + int_pkt->int_desc.vector = vector; + int_pkt->int_desc.reserved = 0; + int_pkt->int_desc.vector_count = vector_count; + int_pkt->int_desc.delivery_mode = DELIVERY_MODE; + int_pkt->int_desc.processor_array[0] = + hv_cpu_number_to_vp_number(cpu); + int_pkt->int_desc.processor_count = 1; + + return sizeof(*int_pkt); +} + +/** + * hv_compose_msi_msg() - Supplies a valid MSI address/data + * @data: Everything about this MSI + * @msg: Buffer that is filled in by this function + * + * This function unpacks the IRQ looking for target CPU set, IDT + * vector and mode and sends a message to the parent partition + * asking for a mapping for that tuple in this partition. The + * response supplies a data value and address to which that data + * should be written to trigger that interrupt. + */ +static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) +{ + struct hv_pcibus_device *hbus; + struct vmbus_channel *channel; + struct hv_pci_dev *hpdev; + struct pci_bus *pbus; + struct pci_dev *pdev; + const struct cpumask *dest; + struct compose_comp_ctxt comp; + struct tran_int_desc *int_desc; + struct msi_desc *msi_desc; + /* + * vector_count should be u16: see hv_msi_desc, hv_msi_desc2 + * and hv_msi_desc3. vector must be u32: see hv_msi_desc3. + */ + u16 vector_count; + u32 vector; + struct { + struct pci_packet pci_pkt; + union { + struct pci_create_interrupt v1; + struct pci_create_interrupt2 v2; + struct pci_create_interrupt3 v3; + } int_pkts; + } __packed ctxt; + bool multi_msi; + u64 trans_id; + u32 size; + int ret; + int cpu; + + msi_desc = irq_data_get_msi_desc(data); + multi_msi = !msi_desc->pci.msi_attrib.is_msix && + msi_desc->nvec_used > 1; + + /* Reuse the previous allocation */ + if (data->chip_data && multi_msi) { + int_desc = data->chip_data; + msg->address_hi = int_desc->address >> 32; + msg->address_lo = int_desc->address & 0xffffffff; + msg->data = int_desc->data; + return; + } + + pdev = msi_desc_to_pci_dev(msi_desc); + dest = irq_data_get_effective_affinity_mask(data); + pbus = pdev->bus; + hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata); + channel = hbus->hdev->channel; + hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn)); + if (!hpdev) + goto return_null_message; + + /* Free any previous message that might have already been composed. */ + if (data->chip_data && !multi_msi) { + int_desc = data->chip_data; + data->chip_data = NULL; + hv_int_desc_free(hpdev, int_desc); + } + + int_desc = kzalloc(sizeof(*int_desc), GFP_ATOMIC); + if (!int_desc) + goto drop_reference; + + if (multi_msi) { + /* + * If this is not the first MSI of Multi MSI, we already have + * a mapping. Can exit early. + */ + if (msi_desc->irq != data->irq) { + data->chip_data = int_desc; + int_desc->address = msi_desc->msg.address_lo | + (u64)msi_desc->msg.address_hi << 32; + int_desc->data = msi_desc->msg.data + + (data->irq - msi_desc->irq); + msg->address_hi = msi_desc->msg.address_hi; + msg->address_lo = msi_desc->msg.address_lo; + msg->data = int_desc->data; + put_pcichild(hpdev); + return; + } + /* + * The vector we select here is a dummy value. The correct + * value gets sent to the hypervisor in unmask(). This needs + * to be aligned with the count, and also not zero. Multi-msi + * is powers of 2 up to 32, so 32 will always work here. + */ + vector = 32; + vector_count = msi_desc->nvec_used; + cpu = hv_compose_multi_msi_req_get_cpu(); + } else { + vector = hv_msi_get_int_vector(data); + vector_count = 1; + cpu = hv_compose_msi_req_get_cpu(dest); + } + + /* + * hv_compose_msi_req_v1 and v2 are for x86 only, meaning 'vector' + * can't exceed u8. Cast 'vector' down to u8 for v1/v2 explicitly + * for better readability. + */ + memset(&ctxt, 0, sizeof(ctxt)); + init_completion(&comp.comp_pkt.host_event); + ctxt.pci_pkt.completion_func = hv_pci_compose_compl; + ctxt.pci_pkt.compl_ctxt = ∁ + + switch (hbus->protocol_version) { + case PCI_PROTOCOL_VERSION_1_1: + size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1, + hpdev->desc.win_slot.slot, + (u8)vector, + vector_count); + break; + + case PCI_PROTOCOL_VERSION_1_2: + case PCI_PROTOCOL_VERSION_1_3: + size = hv_compose_msi_req_v2(&ctxt.int_pkts.v2, + cpu, + hpdev->desc.win_slot.slot, + (u8)vector, + vector_count); + break; + + case PCI_PROTOCOL_VERSION_1_4: + size = hv_compose_msi_req_v3(&ctxt.int_pkts.v3, + cpu, + hpdev->desc.win_slot.slot, + vector, + vector_count); + break; + + default: + /* As we only negotiate protocol versions known to this driver, + * this path should never hit. However, this is it not a hot + * path so we print a message to aid future updates. + */ + dev_err(&hbus->hdev->device, + "Unexpected vPCI protocol, update driver."); + goto free_int_desc; + } + + ret = vmbus_sendpacket_getid(hpdev->hbus->hdev->channel, &ctxt.int_pkts, + size, (unsigned long)&ctxt.pci_pkt, + &trans_id, VM_PKT_DATA_INBAND, + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); + if (ret) { + dev_err(&hbus->hdev->device, + "Sending request for interrupt failed: 0x%x", + comp.comp_pkt.completion_status); + goto free_int_desc; + } + + /* + * Prevents hv_pci_onchannelcallback() from running concurrently + * in the tasklet. + */ + tasklet_disable_in_atomic(&channel->callback_event); + + /* + * Since this function is called with IRQ locks held, can't + * do normal wait for completion; instead poll. + */ + while (!try_wait_for_completion(&comp.comp_pkt.host_event)) { + unsigned long flags; + + /* 0xFFFF means an invalid PCI VENDOR ID. */ + if (hv_pcifront_get_vendor_id(hpdev) == 0xFFFF) { + dev_err_once(&hbus->hdev->device, + "the device has gone\n"); + goto enable_tasklet; + } + + /* + * Make sure that the ring buffer data structure doesn't get + * freed while we dereference the ring buffer pointer. Test + * for the channel's onchannel_callback being NULL within a + * sched_lock critical section. See also the inline comments + * in vmbus_reset_channel_cb(). + */ + spin_lock_irqsave(&channel->sched_lock, flags); + if (unlikely(channel->onchannel_callback == NULL)) { + spin_unlock_irqrestore(&channel->sched_lock, flags); + goto enable_tasklet; + } + hv_pci_onchannelcallback(hbus); + spin_unlock_irqrestore(&channel->sched_lock, flags); + + udelay(100); + } + + tasklet_enable(&channel->callback_event); + + if (comp.comp_pkt.completion_status < 0) { + dev_err(&hbus->hdev->device, + "Request for interrupt failed: 0x%x", + comp.comp_pkt.completion_status); + goto free_int_desc; + } + + /* + * Record the assignment so that this can be unwound later. Using + * irq_set_chip_data() here would be appropriate, but the lock it takes + * is already held. + */ + *int_desc = comp.int_desc; + data->chip_data = int_desc; + + /* Pass up the result. */ + msg->address_hi = comp.int_desc.address >> 32; + msg->address_lo = comp.int_desc.address & 0xffffffff; + msg->data = comp.int_desc.data; + + put_pcichild(hpdev); + return; + +enable_tasklet: + tasklet_enable(&channel->callback_event); + /* + * The completion packet on the stack becomes invalid after 'return'; + * remove the ID from the VMbus requestor if the identifier is still + * mapped to/associated with the packet. (The identifier could have + * been 're-used', i.e., already removed and (re-)mapped.) + * + * Cf. hv_pci_onchannelcallback(). + */ + vmbus_request_addr_match(channel, trans_id, (unsigned long)&ctxt.pci_pkt); +free_int_desc: + kfree(int_desc); +drop_reference: + put_pcichild(hpdev); +return_null_message: + msg->address_hi = 0; + msg->address_lo = 0; + msg->data = 0; +} + +/* HW Interrupt Chip Descriptor */ +static struct irq_chip hv_msi_irq_chip = { + .name = "Hyper-V PCIe MSI", + .irq_compose_msi_msg = hv_compose_msi_msg, + .irq_set_affinity = irq_chip_set_affinity_parent, +#ifdef CONFIG_X86 + .irq_ack = irq_chip_ack_parent, +#elif defined(CONFIG_ARM64) + .irq_eoi = irq_chip_eoi_parent, +#endif + .irq_mask = hv_irq_mask, + .irq_unmask = hv_irq_unmask, +}; + +static struct msi_domain_ops hv_msi_ops = { + .msi_prepare = hv_msi_prepare, + .msi_free = hv_msi_free, +}; + +/** + * hv_pcie_init_irq_domain() - Initialize IRQ domain + * @hbus: The root PCI bus + * + * This function creates an IRQ domain which will be used for + * interrupts from devices that have been passed through. These + * devices only support MSI and MSI-X, not line-based interrupts + * or simulations of line-based interrupts through PCIe's + * fabric-layer messages. Because interrupts are remapped, we + * can support multi-message MSI here. + * + * Return: '0' on success and error value on failure + */ +static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus) +{ + hbus->msi_info.chip = &hv_msi_irq_chip; + hbus->msi_info.ops = &hv_msi_ops; + hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS | + MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI | + MSI_FLAG_PCI_MSIX); + hbus->msi_info.handler = FLOW_HANDLER; + hbus->msi_info.handler_name = FLOW_NAME; + hbus->msi_info.data = hbus; + hbus->irq_domain = pci_msi_create_irq_domain(hbus->fwnode, + &hbus->msi_info, + hv_pci_get_root_domain()); + if (!hbus->irq_domain) { + dev_err(&hbus->hdev->device, + "Failed to build an MSI IRQ domain\n"); + return -ENODEV; + } + + dev_set_msi_domain(&hbus->bridge->dev, hbus->irq_domain); + + return 0; +} + +/** + * get_bar_size() - Get the address space consumed by a BAR + * @bar_val: Value that a BAR returned after -1 was written + * to it. + * + * This function returns the size of the BAR, rounded up to 1 + * page. It has to be rounded up because the hypervisor's page + * table entry that maps the BAR into the VM can't specify an + * offset within a page. The invariant is that the hypervisor + * must place any BARs of smaller than page length at the + * beginning of a page. + * + * Return: Size in bytes of the consumed MMIO space. + */ +static u64 get_bar_size(u64 bar_val) +{ + return round_up((1 + ~(bar_val & PCI_BASE_ADDRESS_MEM_MASK)), + PAGE_SIZE); +} + +/** + * survey_child_resources() - Total all MMIO requirements + * @hbus: Root PCI bus, as understood by this driver + */ +static void survey_child_resources(struct hv_pcibus_device *hbus) +{ + struct hv_pci_dev *hpdev; + resource_size_t bar_size = 0; + unsigned long flags; + struct completion *event; + u64 bar_val; + int i; + + /* If nobody is waiting on the answer, don't compute it. */ + event = xchg(&hbus->survey_event, NULL); + if (!event) + return; + + /* If the answer has already been computed, go with it. */ + if (hbus->low_mmio_space || hbus->high_mmio_space) { + complete(event); + return; + } + + spin_lock_irqsave(&hbus->device_list_lock, flags); + + /* + * Due to an interesting quirk of the PCI spec, all memory regions + * for a child device are a power of 2 in size and aligned in memory, + * so it's sufficient to just add them up without tracking alignment. + */ + list_for_each_entry(hpdev, &hbus->children, list_entry) { + for (i = 0; i < PCI_STD_NUM_BARS; i++) { + if (hpdev->probed_bar[i] & PCI_BASE_ADDRESS_SPACE_IO) + dev_err(&hbus->hdev->device, + "There's an I/O BAR in this list!\n"); + + if (hpdev->probed_bar[i] != 0) { + /* + * A probed BAR has all the upper bits set that + * can be changed. + */ + + bar_val = hpdev->probed_bar[i]; + if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64) + bar_val |= + ((u64)hpdev->probed_bar[++i] << 32); + else + bar_val |= 0xffffffff00000000ULL; + + bar_size = get_bar_size(bar_val); + + if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64) + hbus->high_mmio_space += bar_size; + else + hbus->low_mmio_space += bar_size; + } + } + } + + spin_unlock_irqrestore(&hbus->device_list_lock, flags); + complete(event); +} + +/** + * prepopulate_bars() - Fill in BARs with defaults + * @hbus: Root PCI bus, as understood by this driver + * + * The core PCI driver code seems much, much happier if the BARs + * for a device have values upon first scan. So fill them in. + * The algorithm below works down from large sizes to small, + * attempting to pack the assignments optimally. The assumption, + * enforced in other parts of the code, is that the beginning of + * the memory-mapped I/O space will be aligned on the largest + * BAR size. + */ +static void prepopulate_bars(struct hv_pcibus_device *hbus) +{ + resource_size_t high_size = 0; + resource_size_t low_size = 0; + resource_size_t high_base = 0; + resource_size_t low_base = 0; + resource_size_t bar_size; + struct hv_pci_dev *hpdev; + unsigned long flags; + u64 bar_val; + u32 command; + bool high; + int i; + + if (hbus->low_mmio_space) { + low_size = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space)); + low_base = hbus->low_mmio_res->start; + } + + if (hbus->high_mmio_space) { + high_size = 1ULL << + (63 - __builtin_clzll(hbus->high_mmio_space)); + high_base = hbus->high_mmio_res->start; + } + + spin_lock_irqsave(&hbus->device_list_lock, flags); + + /* + * Clear the memory enable bit, in case it's already set. This occurs + * in the suspend path of hibernation, where the device is suspended, + * resumed and suspended again: see hibernation_snapshot() and + * hibernation_platform_enter(). + * + * If the memory enable bit is already set, Hyper-V silently ignores + * the below BAR updates, and the related PCI device driver can not + * work, because reading from the device register(s) always returns + * 0xFFFFFFFF (PCI_ERROR_RESPONSE). + */ + list_for_each_entry(hpdev, &hbus->children, list_entry) { + _hv_pcifront_read_config(hpdev, PCI_COMMAND, 2, &command); + command &= ~PCI_COMMAND_MEMORY; + _hv_pcifront_write_config(hpdev, PCI_COMMAND, 2, command); + } + + /* Pick addresses for the BARs. */ + do { + list_for_each_entry(hpdev, &hbus->children, list_entry) { + for (i = 0; i < PCI_STD_NUM_BARS; i++) { + bar_val = hpdev->probed_bar[i]; + if (bar_val == 0) + continue; + high = bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64; + if (high) { + bar_val |= + ((u64)hpdev->probed_bar[i + 1] + << 32); + } else { + bar_val |= 0xffffffffULL << 32; + } + bar_size = get_bar_size(bar_val); + if (high) { + if (high_size != bar_size) { + i++; + continue; + } + _hv_pcifront_write_config(hpdev, + PCI_BASE_ADDRESS_0 + (4 * i), + 4, + (u32)(high_base & 0xffffff00)); + i++; + _hv_pcifront_write_config(hpdev, + PCI_BASE_ADDRESS_0 + (4 * i), + 4, (u32)(high_base >> 32)); + high_base += bar_size; + } else { + if (low_size != bar_size) + continue; + _hv_pcifront_write_config(hpdev, + PCI_BASE_ADDRESS_0 + (4 * i), + 4, + (u32)(low_base & 0xffffff00)); + low_base += bar_size; + } + } + if (high_size <= 1 && low_size <= 1) { + /* + * No need to set the PCI_COMMAND_MEMORY bit as + * the core PCI driver doesn't require the bit + * to be pre-set. Actually here we intentionally + * keep the bit off so that the PCI BAR probing + * in the core PCI driver doesn't cause Hyper-V + * to unnecessarily unmap/map the virtual BARs + * from/to the physical BARs multiple times. + * This reduces the VM boot time significantly + * if the BAR sizes are huge. + */ + break; + } + } + + high_size >>= 1; + low_size >>= 1; + } while (high_size || low_size); + + spin_unlock_irqrestore(&hbus->device_list_lock, flags); +} + +/* + * Assign entries in sysfs pci slot directory. + * + * Note that this function does not need to lock the children list + * because it is called from pci_devices_present_work which + * is serialized with hv_eject_device_work because they are on the + * same ordered workqueue. Therefore hbus->children list will not change + * even when pci_create_slot sleeps. + */ +static void hv_pci_assign_slots(struct hv_pcibus_device *hbus) +{ + struct hv_pci_dev *hpdev; + char name[SLOT_NAME_SIZE]; + int slot_nr; + + list_for_each_entry(hpdev, &hbus->children, list_entry) { + if (hpdev->pci_slot) + continue; + + slot_nr = PCI_SLOT(wslot_to_devfn(hpdev->desc.win_slot.slot)); + snprintf(name, SLOT_NAME_SIZE, "%u", hpdev->desc.ser); + hpdev->pci_slot = pci_create_slot(hbus->bridge->bus, slot_nr, + name, NULL); + if (IS_ERR(hpdev->pci_slot)) { + pr_warn("pci_create slot %s failed\n", name); + hpdev->pci_slot = NULL; + } + } +} + +/* + * Remove entries in sysfs pci slot directory. + */ +static void hv_pci_remove_slots(struct hv_pcibus_device *hbus) +{ + struct hv_pci_dev *hpdev; + + list_for_each_entry(hpdev, &hbus->children, list_entry) { + if (!hpdev->pci_slot) + continue; + pci_destroy_slot(hpdev->pci_slot); + hpdev->pci_slot = NULL; + } +} + +/* + * Set NUMA node for the devices on the bus + */ +static void hv_pci_assign_numa_node(struct hv_pcibus_device *hbus) +{ + struct pci_dev *dev; + struct pci_bus *bus = hbus->bridge->bus; + struct hv_pci_dev *hv_dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + hv_dev = get_pcichild_wslot(hbus, devfn_to_wslot(dev->devfn)); + if (!hv_dev) + continue; + + if (hv_dev->desc.flags & HV_PCI_DEVICE_FLAG_NUMA_AFFINITY && + hv_dev->desc.virtual_numa_node < num_possible_nodes()) + /* + * The kernel may boot with some NUMA nodes offline + * (e.g. in a KDUMP kernel) or with NUMA disabled via + * "numa=off". In those cases, adjust the host provided + * NUMA node to a valid NUMA node used by the kernel. + */ + set_dev_node(&dev->dev, + numa_map_to_online_node( + hv_dev->desc.virtual_numa_node)); + + put_pcichild(hv_dev); + } +} + +/** + * create_root_hv_pci_bus() - Expose a new root PCI bus + * @hbus: Root PCI bus, as understood by this driver + * + * Return: 0 on success, -errno on failure + */ +static int create_root_hv_pci_bus(struct hv_pcibus_device *hbus) +{ + int error; + struct pci_host_bridge *bridge = hbus->bridge; + + bridge->dev.parent = &hbus->hdev->device; + bridge->sysdata = &hbus->sysdata; + bridge->ops = &hv_pcifront_ops; + + error = pci_scan_root_bus_bridge(bridge); + if (error) + return error; + + pci_lock_rescan_remove(); + hv_pci_assign_numa_node(hbus); + pci_bus_assign_resources(bridge->bus); + hv_pci_assign_slots(hbus); + pci_bus_add_devices(bridge->bus); + pci_unlock_rescan_remove(); + hbus->state = hv_pcibus_installed; + return 0; +} + +struct q_res_req_compl { + struct completion host_event; + struct hv_pci_dev *hpdev; +}; + +/** + * q_resource_requirements() - Query Resource Requirements + * @context: The completion context. + * @resp: The response that came from the host. + * @resp_packet_size: The size in bytes of resp. + * + * This function is invoked on completion of a Query Resource + * Requirements packet. + */ +static void q_resource_requirements(void *context, struct pci_response *resp, + int resp_packet_size) +{ + struct q_res_req_compl *completion = context; + struct pci_q_res_req_response *q_res_req = + (struct pci_q_res_req_response *)resp; + s32 status; + int i; + + status = (resp_packet_size < sizeof(*q_res_req)) ? -1 : resp->status; + if (status < 0) { + dev_err(&completion->hpdev->hbus->hdev->device, + "query resource requirements failed: %x\n", + status); + } else { + for (i = 0; i < PCI_STD_NUM_BARS; i++) { + completion->hpdev->probed_bar[i] = + q_res_req->probed_bar[i]; + } + } + + complete(&completion->host_event); +} + +/** + * new_pcichild_device() - Create a new child device + * @hbus: The internal struct tracking this root PCI bus. + * @desc: The information supplied so far from the host + * about the device. + * + * This function creates the tracking structure for a new child + * device and kicks off the process of figuring out what it is. + * + * Return: Pointer to the new tracking struct + */ +static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus, + struct hv_pcidev_description *desc) +{ + struct hv_pci_dev *hpdev; + struct pci_child_message *res_req; + struct q_res_req_compl comp_pkt; + struct { + struct pci_packet init_packet; + u8 buffer[sizeof(struct pci_child_message)]; + } pkt; + unsigned long flags; + int ret; + + hpdev = kzalloc(sizeof(*hpdev), GFP_KERNEL); + if (!hpdev) + return NULL; + + hpdev->hbus = hbus; + + memset(&pkt, 0, sizeof(pkt)); + init_completion(&comp_pkt.host_event); + comp_pkt.hpdev = hpdev; + pkt.init_packet.compl_ctxt = &comp_pkt; + pkt.init_packet.completion_func = q_resource_requirements; + res_req = (struct pci_child_message *)&pkt.init_packet.message; + res_req->message_type.type = PCI_QUERY_RESOURCE_REQUIREMENTS; + res_req->wslot.slot = desc->win_slot.slot; + + ret = vmbus_sendpacket(hbus->hdev->channel, res_req, + sizeof(struct pci_child_message), + (unsigned long)&pkt.init_packet, + VM_PKT_DATA_INBAND, + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); + if (ret) + goto error; + + if (wait_for_response(hbus->hdev, &comp_pkt.host_event)) + goto error; + + hpdev->desc = *desc; + refcount_set(&hpdev->refs, 1); + get_pcichild(hpdev); + spin_lock_irqsave(&hbus->device_list_lock, flags); + + list_add_tail(&hpdev->list_entry, &hbus->children); + spin_unlock_irqrestore(&hbus->device_list_lock, flags); + return hpdev; + +error: + kfree(hpdev); + return NULL; +} + +/** + * get_pcichild_wslot() - Find device from slot + * @hbus: Root PCI bus, as understood by this driver + * @wslot: Location on the bus + * + * This function looks up a PCI device and returns the internal + * representation of it. It acquires a reference on it, so that + * the device won't be deleted while somebody is using it. The + * caller is responsible for calling put_pcichild() to release + * this reference. + * + * Return: Internal representation of a PCI device + */ +static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus, + u32 wslot) +{ + unsigned long flags; + struct hv_pci_dev *iter, *hpdev = NULL; + + spin_lock_irqsave(&hbus->device_list_lock, flags); + list_for_each_entry(iter, &hbus->children, list_entry) { + if (iter->desc.win_slot.slot == wslot) { + hpdev = iter; + get_pcichild(hpdev); + break; + } + } + spin_unlock_irqrestore(&hbus->device_list_lock, flags); + + return hpdev; +} + +/** + * pci_devices_present_work() - Handle new list of child devices + * @work: Work struct embedded in struct hv_dr_work + * + * "Bus Relations" is the Windows term for "children of this + * bus." The terminology is preserved here for people trying to + * debug the interaction between Hyper-V and Linux. This + * function is called when the parent partition reports a list + * of functions that should be observed under this PCI Express + * port (bus). + * + * This function updates the list, and must tolerate being + * called multiple times with the same information. The typical + * number of child devices is one, with very atypical cases + * involving three or four, so the algorithms used here can be + * simple and inefficient. + * + * It must also treat the omission of a previously observed device as + * notification that the device no longer exists. + * + * Note that this function is serialized with hv_eject_device_work(), + * because both are pushed to the ordered workqueue hbus->wq. + */ +static void pci_devices_present_work(struct work_struct *work) +{ + u32 child_no; + bool found; + struct hv_pcidev_description *new_desc; + struct hv_pci_dev *hpdev; + struct hv_pcibus_device *hbus; + struct list_head removed; + struct hv_dr_work *dr_wrk; + struct hv_dr_state *dr = NULL; + unsigned long flags; + + dr_wrk = container_of(work, struct hv_dr_work, wrk); + hbus = dr_wrk->bus; + kfree(dr_wrk); + + INIT_LIST_HEAD(&removed); + + /* Pull this off the queue and process it if it was the last one. */ + spin_lock_irqsave(&hbus->device_list_lock, flags); + while (!list_empty(&hbus->dr_list)) { + dr = list_first_entry(&hbus->dr_list, struct hv_dr_state, + list_entry); + list_del(&dr->list_entry); + + /* Throw this away if the list still has stuff in it. */ + if (!list_empty(&hbus->dr_list)) { + kfree(dr); + continue; + } + } + spin_unlock_irqrestore(&hbus->device_list_lock, flags); + + if (!dr) + return; + + mutex_lock(&hbus->state_lock); + + /* First, mark all existing children as reported missing. */ + spin_lock_irqsave(&hbus->device_list_lock, flags); + list_for_each_entry(hpdev, &hbus->children, list_entry) { + hpdev->reported_missing = true; + } + spin_unlock_irqrestore(&hbus->device_list_lock, flags); + + /* Next, add back any reported devices. */ + for (child_no = 0; child_no < dr->device_count; child_no++) { + found = false; + new_desc = &dr->func[child_no]; + + spin_lock_irqsave(&hbus->device_list_lock, flags); + list_for_each_entry(hpdev, &hbus->children, list_entry) { + if ((hpdev->desc.win_slot.slot == new_desc->win_slot.slot) && + (hpdev->desc.v_id == new_desc->v_id) && + (hpdev->desc.d_id == new_desc->d_id) && + (hpdev->desc.ser == new_desc->ser)) { + hpdev->reported_missing = false; + found = true; + } + } + spin_unlock_irqrestore(&hbus->device_list_lock, flags); + + if (!found) { + hpdev = new_pcichild_device(hbus, new_desc); + if (!hpdev) + dev_err(&hbus->hdev->device, + "couldn't record a child device.\n"); + } + } + + /* Move missing children to a list on the stack. */ + spin_lock_irqsave(&hbus->device_list_lock, flags); + do { + found = false; + list_for_each_entry(hpdev, &hbus->children, list_entry) { + if (hpdev->reported_missing) { + found = true; + put_pcichild(hpdev); + list_move_tail(&hpdev->list_entry, &removed); + break; + } + } + } while (found); + spin_unlock_irqrestore(&hbus->device_list_lock, flags); + + /* Delete everything that should no longer exist. */ + while (!list_empty(&removed)) { + hpdev = list_first_entry(&removed, struct hv_pci_dev, + list_entry); + list_del(&hpdev->list_entry); + + if (hpdev->pci_slot) + pci_destroy_slot(hpdev->pci_slot); + + put_pcichild(hpdev); + } + + switch (hbus->state) { + case hv_pcibus_installed: + /* + * Tell the core to rescan bus + * because there may have been changes. + */ + pci_lock_rescan_remove(); + pci_scan_child_bus(hbus->bridge->bus); + hv_pci_assign_numa_node(hbus); + hv_pci_assign_slots(hbus); + pci_unlock_rescan_remove(); + break; + + case hv_pcibus_init: + case hv_pcibus_probed: + survey_child_resources(hbus); + break; + + default: + break; + } + + mutex_unlock(&hbus->state_lock); + + kfree(dr); +} + +/** + * hv_pci_start_relations_work() - Queue work to start device discovery + * @hbus: Root PCI bus, as understood by this driver + * @dr: The list of children returned from host + * + * Return: 0 on success, -errno on failure + */ +static int hv_pci_start_relations_work(struct hv_pcibus_device *hbus, + struct hv_dr_state *dr) +{ + struct hv_dr_work *dr_wrk; + unsigned long flags; + bool pending_dr; + + if (hbus->state == hv_pcibus_removing) { + dev_info(&hbus->hdev->device, + "PCI VMBus BUS_RELATIONS: ignored\n"); + return -ENOENT; + } + + dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT); + if (!dr_wrk) + return -ENOMEM; + + INIT_WORK(&dr_wrk->wrk, pci_devices_present_work); + dr_wrk->bus = hbus; + + spin_lock_irqsave(&hbus->device_list_lock, flags); + /* + * If pending_dr is true, we have already queued a work, + * which will see the new dr. Otherwise, we need to + * queue a new work. + */ + pending_dr = !list_empty(&hbus->dr_list); + list_add_tail(&dr->list_entry, &hbus->dr_list); + spin_unlock_irqrestore(&hbus->device_list_lock, flags); + + if (pending_dr) + kfree(dr_wrk); + else + queue_work(hbus->wq, &dr_wrk->wrk); + + return 0; +} + +/** + * hv_pci_devices_present() - Handle list of new children + * @hbus: Root PCI bus, as understood by this driver + * @relations: Packet from host listing children + * + * Process a new list of devices on the bus. The list of devices is + * discovered by VSP and sent to us via VSP message PCI_BUS_RELATIONS, + * whenever a new list of devices for this bus appears. + */ +static void hv_pci_devices_present(struct hv_pcibus_device *hbus, + struct pci_bus_relations *relations) +{ + struct hv_dr_state *dr; + int i; + + dr = kzalloc(struct_size(dr, func, relations->device_count), + GFP_NOWAIT); + if (!dr) + return; + + dr->device_count = relations->device_count; + for (i = 0; i < dr->device_count; i++) { + dr->func[i].v_id = relations->func[i].v_id; + dr->func[i].d_id = relations->func[i].d_id; + dr->func[i].rev = relations->func[i].rev; + dr->func[i].prog_intf = relations->func[i].prog_intf; + dr->func[i].subclass = relations->func[i].subclass; + dr->func[i].base_class = relations->func[i].base_class; + dr->func[i].subsystem_id = relations->func[i].subsystem_id; + dr->func[i].win_slot = relations->func[i].win_slot; + dr->func[i].ser = relations->func[i].ser; + } + + if (hv_pci_start_relations_work(hbus, dr)) + kfree(dr); +} + +/** + * hv_pci_devices_present2() - Handle list of new children + * @hbus: Root PCI bus, as understood by this driver + * @relations: Packet from host listing children + * + * This function is the v2 version of hv_pci_devices_present() + */ +static void hv_pci_devices_present2(struct hv_pcibus_device *hbus, + struct pci_bus_relations2 *relations) +{ + struct hv_dr_state *dr; + int i; + + dr = kzalloc(struct_size(dr, func, relations->device_count), + GFP_NOWAIT); + if (!dr) + return; + + dr->device_count = relations->device_count; + for (i = 0; i < dr->device_count; i++) { + dr->func[i].v_id = relations->func[i].v_id; + dr->func[i].d_id = relations->func[i].d_id; + dr->func[i].rev = relations->func[i].rev; + dr->func[i].prog_intf = relations->func[i].prog_intf; + dr->func[i].subclass = relations->func[i].subclass; + dr->func[i].base_class = relations->func[i].base_class; + dr->func[i].subsystem_id = relations->func[i].subsystem_id; + dr->func[i].win_slot = relations->func[i].win_slot; + dr->func[i].ser = relations->func[i].ser; + dr->func[i].flags = relations->func[i].flags; + dr->func[i].virtual_numa_node = + relations->func[i].virtual_numa_node; + } + + if (hv_pci_start_relations_work(hbus, dr)) + kfree(dr); +} + +/** + * hv_eject_device_work() - Asynchronously handles ejection + * @work: Work struct embedded in internal device struct + * + * This function handles ejecting a device. Windows will + * attempt to gracefully eject a device, waiting 60 seconds to + * hear back from the guest OS that this completed successfully. + * If this timer expires, the device will be forcibly removed. + */ +static void hv_eject_device_work(struct work_struct *work) +{ + struct pci_eject_response *ejct_pkt; + struct hv_pcibus_device *hbus; + struct hv_pci_dev *hpdev; + struct pci_dev *pdev; + unsigned long flags; + int wslot; + struct { + struct pci_packet pkt; + u8 buffer[sizeof(struct pci_eject_response)]; + } ctxt; + + hpdev = container_of(work, struct hv_pci_dev, wrk); + hbus = hpdev->hbus; + + mutex_lock(&hbus->state_lock); + + /* + * Ejection can come before or after the PCI bus has been set up, so + * attempt to find it and tear down the bus state, if it exists. This + * must be done without constructs like pci_domain_nr(hbus->bridge->bus) + * because hbus->bridge->bus may not exist yet. + */ + wslot = wslot_to_devfn(hpdev->desc.win_slot.slot); + pdev = pci_get_domain_bus_and_slot(hbus->bridge->domain_nr, 0, wslot); + if (pdev) { + pci_lock_rescan_remove(); + pci_stop_and_remove_bus_device(pdev); + pci_dev_put(pdev); + pci_unlock_rescan_remove(); + } + + spin_lock_irqsave(&hbus->device_list_lock, flags); + list_del(&hpdev->list_entry); + spin_unlock_irqrestore(&hbus->device_list_lock, flags); + + if (hpdev->pci_slot) + pci_destroy_slot(hpdev->pci_slot); + + memset(&ctxt, 0, sizeof(ctxt)); + ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message; + ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE; + ejct_pkt->wslot.slot = hpdev->desc.win_slot.slot; + vmbus_sendpacket(hbus->hdev->channel, ejct_pkt, + sizeof(*ejct_pkt), 0, + VM_PKT_DATA_INBAND, 0); + + /* For the get_pcichild() in hv_pci_eject_device() */ + put_pcichild(hpdev); + /* For the two refs got in new_pcichild_device() */ + put_pcichild(hpdev); + put_pcichild(hpdev); + /* hpdev has been freed. Do not use it any more. */ + + mutex_unlock(&hbus->state_lock); +} + +/** + * hv_pci_eject_device() - Handles device ejection + * @hpdev: Internal device tracking struct + * + * This function is invoked when an ejection packet arrives. It + * just schedules work so that we don't re-enter the packet + * delivery code handling the ejection. + */ +static void hv_pci_eject_device(struct hv_pci_dev *hpdev) +{ + struct hv_pcibus_device *hbus = hpdev->hbus; + struct hv_device *hdev = hbus->hdev; + + if (hbus->state == hv_pcibus_removing) { + dev_info(&hdev->device, "PCI VMBus EJECT: ignored\n"); + return; + } + + get_pcichild(hpdev); + INIT_WORK(&hpdev->wrk, hv_eject_device_work); + queue_work(hbus->wq, &hpdev->wrk); +} + +/** + * hv_pci_onchannelcallback() - Handles incoming packets + * @context: Internal bus tracking struct + * + * This function is invoked whenever the host sends a packet to + * this channel (which is private to this root PCI bus). + */ +static void hv_pci_onchannelcallback(void *context) +{ + const int packet_size = 0x100; + int ret; + struct hv_pcibus_device *hbus = context; + struct vmbus_channel *chan = hbus->hdev->channel; + u32 bytes_recvd; + u64 req_id, req_addr; + struct vmpacket_descriptor *desc; + unsigned char *buffer; + int bufferlen = packet_size; + struct pci_packet *comp_packet; + struct pci_response *response; + struct pci_incoming_message *new_message; + struct pci_bus_relations *bus_rel; + struct pci_bus_relations2 *bus_rel2; + struct pci_dev_inval_block *inval; + struct pci_dev_incoming *dev_message; + struct hv_pci_dev *hpdev; + unsigned long flags; + + buffer = kmalloc(bufferlen, GFP_ATOMIC); + if (!buffer) + return; + + while (1) { + ret = vmbus_recvpacket_raw(chan, buffer, bufferlen, + &bytes_recvd, &req_id); + + if (ret == -ENOBUFS) { + kfree(buffer); + /* Handle large packet */ + bufferlen = bytes_recvd; + buffer = kmalloc(bytes_recvd, GFP_ATOMIC); + if (!buffer) + return; + continue; + } + + /* Zero length indicates there are no more packets. */ + if (ret || !bytes_recvd) + break; + + /* + * All incoming packets must be at least as large as a + * response. + */ + if (bytes_recvd <= sizeof(struct pci_response)) + continue; + desc = (struct vmpacket_descriptor *)buffer; + + switch (desc->type) { + case VM_PKT_COMP: + + lock_requestor(chan, flags); + req_addr = __vmbus_request_addr_match(chan, req_id, + VMBUS_RQST_ADDR_ANY); + if (req_addr == VMBUS_RQST_ERROR) { + unlock_requestor(chan, flags); + dev_err(&hbus->hdev->device, + "Invalid transaction ID %llx\n", + req_id); + break; + } + comp_packet = (struct pci_packet *)req_addr; + response = (struct pci_response *)buffer; + /* + * Call ->completion_func() within the critical section to make + * sure that the packet pointer is still valid during the call: + * here 'valid' means that there's a task still waiting for the + * completion, and that the packet data is still on the waiting + * task's stack. Cf. hv_compose_msi_msg(). + */ + comp_packet->completion_func(comp_packet->compl_ctxt, + response, + bytes_recvd); + unlock_requestor(chan, flags); + break; + + case VM_PKT_DATA_INBAND: + + new_message = (struct pci_incoming_message *)buffer; + switch (new_message->message_type.type) { + case PCI_BUS_RELATIONS: + + bus_rel = (struct pci_bus_relations *)buffer; + if (bytes_recvd < sizeof(*bus_rel) || + bytes_recvd < + struct_size(bus_rel, func, + bus_rel->device_count)) { + dev_err(&hbus->hdev->device, + "bus relations too small\n"); + break; + } + + hv_pci_devices_present(hbus, bus_rel); + break; + + case PCI_BUS_RELATIONS2: + + bus_rel2 = (struct pci_bus_relations2 *)buffer; + if (bytes_recvd < sizeof(*bus_rel2) || + bytes_recvd < + struct_size(bus_rel2, func, + bus_rel2->device_count)) { + dev_err(&hbus->hdev->device, + "bus relations v2 too small\n"); + break; + } + + hv_pci_devices_present2(hbus, bus_rel2); + break; + + case PCI_EJECT: + + dev_message = (struct pci_dev_incoming *)buffer; + if (bytes_recvd < sizeof(*dev_message)) { + dev_err(&hbus->hdev->device, + "eject message too small\n"); + break; + } + hpdev = get_pcichild_wslot(hbus, + dev_message->wslot.slot); + if (hpdev) { + hv_pci_eject_device(hpdev); + put_pcichild(hpdev); + } + break; + + case PCI_INVALIDATE_BLOCK: + + inval = (struct pci_dev_inval_block *)buffer; + if (bytes_recvd < sizeof(*inval)) { + dev_err(&hbus->hdev->device, + "invalidate message too small\n"); + break; + } + hpdev = get_pcichild_wslot(hbus, + inval->wslot.slot); + if (hpdev) { + if (hpdev->block_invalidate) { + hpdev->block_invalidate( + hpdev->invalidate_context, + inval->block_mask); + } + put_pcichild(hpdev); + } + break; + + default: + dev_warn(&hbus->hdev->device, + "Unimplemented protocol message %x\n", + new_message->message_type.type); + break; + } + break; + + default: + dev_err(&hbus->hdev->device, + "unhandled packet type %d, tid %llx len %d\n", + desc->type, req_id, bytes_recvd); + break; + } + } + + kfree(buffer); +} + +/** + * hv_pci_protocol_negotiation() - Set up protocol + * @hdev: VMBus's tracking struct for this root PCI bus. + * @version: Array of supported channel protocol versions in + * the order of probing - highest go first. + * @num_version: Number of elements in the version array. + * + * This driver is intended to support running on Windows 10 + * (server) and later versions. It will not run on earlier + * versions, as they assume that many of the operations which + * Linux needs accomplished with a spinlock held were done via + * asynchronous messaging via VMBus. Windows 10 increases the + * surface area of PCI emulation so that these actions can take + * place by suspending a virtual processor for their duration. + * + * This function negotiates the channel protocol version, + * failing if the host doesn't support the necessary protocol + * level. + */ +static int hv_pci_protocol_negotiation(struct hv_device *hdev, + enum pci_protocol_version_t version[], + int num_version) +{ + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); + struct pci_version_request *version_req; + struct hv_pci_compl comp_pkt; + struct pci_packet *pkt; + int ret; + int i; + + /* + * Initiate the handshake with the host and negotiate + * a version that the host can support. We start with the + * highest version number and go down if the host cannot + * support it. + */ + pkt = kzalloc(sizeof(*pkt) + sizeof(*version_req), GFP_KERNEL); + if (!pkt) + return -ENOMEM; + + init_completion(&comp_pkt.host_event); + pkt->completion_func = hv_pci_generic_compl; + pkt->compl_ctxt = &comp_pkt; + version_req = (struct pci_version_request *)&pkt->message; + version_req->message_type.type = PCI_QUERY_PROTOCOL_VERSION; + + for (i = 0; i < num_version; i++) { + version_req->protocol_version = version[i]; + ret = vmbus_sendpacket(hdev->channel, version_req, + sizeof(struct pci_version_request), + (unsigned long)pkt, VM_PKT_DATA_INBAND, + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); + if (!ret) + ret = wait_for_response(hdev, &comp_pkt.host_event); + + if (ret) { + dev_err(&hdev->device, + "PCI Pass-through VSP failed to request version: %d", + ret); + goto exit; + } + + if (comp_pkt.completion_status >= 0) { + hbus->protocol_version = version[i]; + dev_info(&hdev->device, + "PCI VMBus probing: Using version %#x\n", + hbus->protocol_version); + goto exit; + } + + if (comp_pkt.completion_status != STATUS_REVISION_MISMATCH) { + dev_err(&hdev->device, + "PCI Pass-through VSP failed version request: %#x", + comp_pkt.completion_status); + ret = -EPROTO; + goto exit; + } + + reinit_completion(&comp_pkt.host_event); + } + + dev_err(&hdev->device, + "PCI pass-through VSP failed to find supported version"); + ret = -EPROTO; + +exit: + kfree(pkt); + return ret; +} + +/** + * hv_pci_free_bridge_windows() - Release memory regions for the + * bus + * @hbus: Root PCI bus, as understood by this driver + */ +static void hv_pci_free_bridge_windows(struct hv_pcibus_device *hbus) +{ + /* + * Set the resources back to the way they looked when they + * were allocated by setting IORESOURCE_BUSY again. + */ + + if (hbus->low_mmio_space && hbus->low_mmio_res) { + hbus->low_mmio_res->flags |= IORESOURCE_BUSY; + vmbus_free_mmio(hbus->low_mmio_res->start, + resource_size(hbus->low_mmio_res)); + } + + if (hbus->high_mmio_space && hbus->high_mmio_res) { + hbus->high_mmio_res->flags |= IORESOURCE_BUSY; + vmbus_free_mmio(hbus->high_mmio_res->start, + resource_size(hbus->high_mmio_res)); + } +} + +/** + * hv_pci_allocate_bridge_windows() - Allocate memory regions + * for the bus + * @hbus: Root PCI bus, as understood by this driver + * + * This function calls vmbus_allocate_mmio(), which is itself a + * bit of a compromise. Ideally, we might change the pnp layer + * in the kernel such that it comprehends either PCI devices + * which are "grandchildren of ACPI," with some intermediate bus + * node (in this case, VMBus) or change it such that it + * understands VMBus. The pnp layer, however, has been declared + * deprecated, and not subject to change. + * + * The workaround, implemented here, is to ask VMBus to allocate + * MMIO space for this bus. VMBus itself knows which ranges are + * appropriate by looking at its own ACPI objects. Then, after + * these ranges are claimed, they're modified to look like they + * would have looked if the ACPI and pnp code had allocated + * bridge windows. These descriptors have to exist in this form + * in order to satisfy the code which will get invoked when the + * endpoint PCI function driver calls request_mem_region() or + * request_mem_region_exclusive(). + * + * Return: 0 on success, -errno on failure + */ +static int hv_pci_allocate_bridge_windows(struct hv_pcibus_device *hbus) +{ + resource_size_t align; + int ret; + + if (hbus->low_mmio_space) { + align = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space)); + ret = vmbus_allocate_mmio(&hbus->low_mmio_res, hbus->hdev, 0, + (u64)(u32)0xffffffff, + hbus->low_mmio_space, + align, false); + if (ret) { + dev_err(&hbus->hdev->device, + "Need %#llx of low MMIO space. Consider reconfiguring the VM.\n", + hbus->low_mmio_space); + return ret; + } + + /* Modify this resource to become a bridge window. */ + hbus->low_mmio_res->flags |= IORESOURCE_WINDOW; + hbus->low_mmio_res->flags &= ~IORESOURCE_BUSY; + pci_add_resource(&hbus->bridge->windows, hbus->low_mmio_res); + } + + if (hbus->high_mmio_space) { + align = 1ULL << (63 - __builtin_clzll(hbus->high_mmio_space)); + ret = vmbus_allocate_mmio(&hbus->high_mmio_res, hbus->hdev, + 0x100000000, -1, + hbus->high_mmio_space, align, + false); + if (ret) { + dev_err(&hbus->hdev->device, + "Need %#llx of high MMIO space. Consider reconfiguring the VM.\n", + hbus->high_mmio_space); + goto release_low_mmio; + } + + /* Modify this resource to become a bridge window. */ + hbus->high_mmio_res->flags |= IORESOURCE_WINDOW; + hbus->high_mmio_res->flags &= ~IORESOURCE_BUSY; + pci_add_resource(&hbus->bridge->windows, hbus->high_mmio_res); + } + + return 0; + +release_low_mmio: + if (hbus->low_mmio_res) { + vmbus_free_mmio(hbus->low_mmio_res->start, + resource_size(hbus->low_mmio_res)); + } + + return ret; +} + +/** + * hv_allocate_config_window() - Find MMIO space for PCI Config + * @hbus: Root PCI bus, as understood by this driver + * + * This function claims memory-mapped I/O space for accessing + * configuration space for the functions on this bus. + * + * Return: 0 on success, -errno on failure + */ +static int hv_allocate_config_window(struct hv_pcibus_device *hbus) +{ + int ret; + + /* + * Set up a region of MMIO space to use for accessing configuration + * space. + */ + ret = vmbus_allocate_mmio(&hbus->mem_config, hbus->hdev, 0, -1, + PCI_CONFIG_MMIO_LENGTH, 0x1000, false); + if (ret) + return ret; + + /* + * vmbus_allocate_mmio() gets used for allocating both device endpoint + * resource claims (those which cannot be overlapped) and the ranges + * which are valid for the children of this bus, which are intended + * to be overlapped by those children. Set the flag on this claim + * meaning that this region can't be overlapped. + */ + + hbus->mem_config->flags |= IORESOURCE_BUSY; + + return 0; +} + +static void hv_free_config_window(struct hv_pcibus_device *hbus) +{ + vmbus_free_mmio(hbus->mem_config->start, PCI_CONFIG_MMIO_LENGTH); +} + +static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs); + +/** + * hv_pci_enter_d0() - Bring the "bus" into the D0 power state + * @hdev: VMBus's tracking struct for this root PCI bus + * + * Return: 0 on success, -errno on failure + */ +static int hv_pci_enter_d0(struct hv_device *hdev) +{ + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); + struct pci_bus_d0_entry *d0_entry; + struct hv_pci_compl comp_pkt; + struct pci_packet *pkt; + bool retry = true; + int ret; + +enter_d0_retry: + /* + * Tell the host that the bus is ready to use, and moved into the + * powered-on state. This includes telling the host which region + * of memory-mapped I/O space has been chosen for configuration space + * access. + */ + pkt = kzalloc(sizeof(*pkt) + sizeof(*d0_entry), GFP_KERNEL); + if (!pkt) + return -ENOMEM; + + init_completion(&comp_pkt.host_event); + pkt->completion_func = hv_pci_generic_compl; + pkt->compl_ctxt = &comp_pkt; + d0_entry = (struct pci_bus_d0_entry *)&pkt->message; + d0_entry->message_type.type = PCI_BUS_D0ENTRY; + d0_entry->mmio_base = hbus->mem_config->start; + + ret = vmbus_sendpacket(hdev->channel, d0_entry, sizeof(*d0_entry), + (unsigned long)pkt, VM_PKT_DATA_INBAND, + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); + if (!ret) + ret = wait_for_response(hdev, &comp_pkt.host_event); + + if (ret) + goto exit; + + /* + * In certain case (Kdump) the pci device of interest was + * not cleanly shut down and resource is still held on host + * side, the host could return invalid device status. + * We need to explicitly request host to release the resource + * and try to enter D0 again. + */ + if (comp_pkt.completion_status < 0 && retry) { + retry = false; + + dev_err(&hdev->device, "Retrying D0 Entry\n"); + + /* + * Hv_pci_bus_exit() calls hv_send_resource_released() + * to free up resources of its child devices. + * In the kdump kernel we need to set the + * wslot_res_allocated to 255 so it scans all child + * devices to release resources allocated in the + * normal kernel before panic happened. + */ + hbus->wslot_res_allocated = 255; + + ret = hv_pci_bus_exit(hdev, true); + + if (ret == 0) { + kfree(pkt); + goto enter_d0_retry; + } + dev_err(&hdev->device, + "Retrying D0 failed with ret %d\n", ret); + } + + if (comp_pkt.completion_status < 0) { + dev_err(&hdev->device, + "PCI Pass-through VSP failed D0 Entry with status %x\n", + comp_pkt.completion_status); + ret = -EPROTO; + goto exit; + } + + ret = 0; + +exit: + kfree(pkt); + return ret; +} + +/** + * hv_pci_query_relations() - Ask host to send list of child + * devices + * @hdev: VMBus's tracking struct for this root PCI bus + * + * Return: 0 on success, -errno on failure + */ +static int hv_pci_query_relations(struct hv_device *hdev) +{ + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); + struct pci_message message; + struct completion comp; + int ret; + + /* Ask the host to send along the list of child devices */ + init_completion(&comp); + if (cmpxchg(&hbus->survey_event, NULL, &comp)) + return -ENOTEMPTY; + + memset(&message, 0, sizeof(message)); + message.type = PCI_QUERY_BUS_RELATIONS; + + ret = vmbus_sendpacket(hdev->channel, &message, sizeof(message), + 0, VM_PKT_DATA_INBAND, 0); + if (!ret) + ret = wait_for_response(hdev, &comp); + + /* + * In the case of fast device addition/removal, it's possible that + * vmbus_sendpacket() or wait_for_response() returns -ENODEV but we + * already got a PCI_BUS_RELATIONS* message from the host and the + * channel callback already scheduled a work to hbus->wq, which can be + * running pci_devices_present_work() -> survey_child_resources() -> + * complete(&hbus->survey_event), even after hv_pci_query_relations() + * exits and the stack variable 'comp' is no longer valid; as a result, + * a hang or a page fault may happen when the complete() calls + * raw_spin_lock_irqsave(). Flush hbus->wq before we exit from + * hv_pci_query_relations() to avoid the issues. Note: if 'ret' is + * -ENODEV, there can't be any more work item scheduled to hbus->wq + * after the flush_workqueue(): see vmbus_onoffer_rescind() -> + * vmbus_reset_channel_cb(), vmbus_rescind_cleanup() -> + * channel->rescind = true. + */ + flush_workqueue(hbus->wq); + + return ret; +} + +/** + * hv_send_resources_allocated() - Report local resource choices + * @hdev: VMBus's tracking struct for this root PCI bus + * + * The host OS is expecting to be sent a request as a message + * which contains all the resources that the device will use. + * The response contains those same resources, "translated" + * which is to say, the values which should be used by the + * hardware, when it delivers an interrupt. (MMIO resources are + * used in local terms.) This is nice for Windows, and lines up + * with the FDO/PDO split, which doesn't exist in Linux. Linux + * is deeply expecting to scan an emulated PCI configuration + * space. So this message is sent here only to drive the state + * machine on the host forward. + * + * Return: 0 on success, -errno on failure + */ +static int hv_send_resources_allocated(struct hv_device *hdev) +{ + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); + struct pci_resources_assigned *res_assigned; + struct pci_resources_assigned2 *res_assigned2; + struct hv_pci_compl comp_pkt; + struct hv_pci_dev *hpdev; + struct pci_packet *pkt; + size_t size_res; + int wslot; + int ret; + + size_res = (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2) + ? sizeof(*res_assigned) : sizeof(*res_assigned2); + + pkt = kmalloc(sizeof(*pkt) + size_res, GFP_KERNEL); + if (!pkt) + return -ENOMEM; + + ret = 0; + + for (wslot = 0; wslot < 256; wslot++) { + hpdev = get_pcichild_wslot(hbus, wslot); + if (!hpdev) + continue; + + memset(pkt, 0, sizeof(*pkt) + size_res); + init_completion(&comp_pkt.host_event); + pkt->completion_func = hv_pci_generic_compl; + pkt->compl_ctxt = &comp_pkt; + + if (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2) { + res_assigned = + (struct pci_resources_assigned *)&pkt->message; + res_assigned->message_type.type = + PCI_RESOURCES_ASSIGNED; + res_assigned->wslot.slot = hpdev->desc.win_slot.slot; + } else { + res_assigned2 = + (struct pci_resources_assigned2 *)&pkt->message; + res_assigned2->message_type.type = + PCI_RESOURCES_ASSIGNED2; + res_assigned2->wslot.slot = hpdev->desc.win_slot.slot; + } + put_pcichild(hpdev); + + ret = vmbus_sendpacket(hdev->channel, &pkt->message, + size_res, (unsigned long)pkt, + VM_PKT_DATA_INBAND, + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); + if (!ret) + ret = wait_for_response(hdev, &comp_pkt.host_event); + if (ret) + break; + + if (comp_pkt.completion_status < 0) { + ret = -EPROTO; + dev_err(&hdev->device, + "resource allocated returned 0x%x", + comp_pkt.completion_status); + break; + } + + hbus->wslot_res_allocated = wslot; + } + + kfree(pkt); + return ret; +} + +/** + * hv_send_resources_released() - Report local resources + * released + * @hdev: VMBus's tracking struct for this root PCI bus + * + * Return: 0 on success, -errno on failure + */ +static int hv_send_resources_released(struct hv_device *hdev) +{ + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); + struct pci_child_message pkt; + struct hv_pci_dev *hpdev; + int wslot; + int ret; + + for (wslot = hbus->wslot_res_allocated; wslot >= 0; wslot--) { + hpdev = get_pcichild_wslot(hbus, wslot); + if (!hpdev) + continue; + + memset(&pkt, 0, sizeof(pkt)); + pkt.message_type.type = PCI_RESOURCES_RELEASED; + pkt.wslot.slot = hpdev->desc.win_slot.slot; + + put_pcichild(hpdev); + + ret = vmbus_sendpacket(hdev->channel, &pkt, sizeof(pkt), 0, + VM_PKT_DATA_INBAND, 0); + if (ret) + return ret; + + hbus->wslot_res_allocated = wslot - 1; + } + + hbus->wslot_res_allocated = -1; + + return 0; +} + +#define HVPCI_DOM_MAP_SIZE (64 * 1024) +static DECLARE_BITMAP(hvpci_dom_map, HVPCI_DOM_MAP_SIZE); + +/* + * PCI domain number 0 is used by emulated devices on Gen1 VMs, so define 0 + * as invalid for passthrough PCI devices of this driver. + */ +#define HVPCI_DOM_INVALID 0 + +/** + * hv_get_dom_num() - Get a valid PCI domain number + * Check if the PCI domain number is in use, and return another number if + * it is in use. + * + * @dom: Requested domain number + * + * return: domain number on success, HVPCI_DOM_INVALID on failure + */ +static u16 hv_get_dom_num(u16 dom) +{ + unsigned int i; + + if (test_and_set_bit(dom, hvpci_dom_map) == 0) + return dom; + + for_each_clear_bit(i, hvpci_dom_map, HVPCI_DOM_MAP_SIZE) { + if (test_and_set_bit(i, hvpci_dom_map) == 0) + return i; + } + + return HVPCI_DOM_INVALID; +} + +/** + * hv_put_dom_num() - Mark the PCI domain number as free + * @dom: Domain number to be freed + */ +static void hv_put_dom_num(u16 dom) +{ + clear_bit(dom, hvpci_dom_map); +} + +/** + * hv_pci_probe() - New VMBus channel probe, for a root PCI bus + * @hdev: VMBus's tracking struct for this root PCI bus + * @dev_id: Identifies the device itself + * + * Return: 0 on success, -errno on failure + */ +static int hv_pci_probe(struct hv_device *hdev, + const struct hv_vmbus_device_id *dev_id) +{ + struct pci_host_bridge *bridge; + struct hv_pcibus_device *hbus; + u16 dom_req, dom; + char *name; + int ret; + + /* + * hv_pcibus_device contains the hypercall arguments for retargeting in + * hv_irq_unmask(). Those must not cross a page boundary. + */ + BUILD_BUG_ON(sizeof(*hbus) > HV_HYP_PAGE_SIZE); + + bridge = devm_pci_alloc_host_bridge(&hdev->device, 0); + if (!bridge) + return -ENOMEM; + + /* + * With the recent 59bb47985c1d ("mm, sl[aou]b: guarantee natural + * alignment for kmalloc(power-of-two)"), kzalloc() is able to allocate + * a 4KB buffer that is guaranteed to be 4KB-aligned. Here the size and + * alignment of hbus is important because hbus's field + * retarget_msi_interrupt_params must not cross a 4KB page boundary. + * + * Here we prefer kzalloc to get_zeroed_page(), because a buffer + * allocated by the latter is not tracked and scanned by kmemleak, and + * hence kmemleak reports the pointer contained in the hbus buffer + * (i.e. the hpdev struct, which is created in new_pcichild_device() and + * is tracked by hbus->children) as memory leak (false positive). + * + * If the kernel doesn't have 59bb47985c1d, get_zeroed_page() *must* be + * used to allocate the hbus buffer and we can avoid the kmemleak false + * positive by using kmemleak_alloc() and kmemleak_free() to ask + * kmemleak to track and scan the hbus buffer. + */ + hbus = kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL); + if (!hbus) + return -ENOMEM; + + hbus->bridge = bridge; + mutex_init(&hbus->state_lock); + hbus->state = hv_pcibus_init; + hbus->wslot_res_allocated = -1; + + /* + * The PCI bus "domain" is what is called "segment" in ACPI and other + * specs. Pull it from the instance ID, to get something usually + * unique. In rare cases of collision, we will find out another number + * not in use. + * + * Note that, since this code only runs in a Hyper-V VM, Hyper-V + * together with this guest driver can guarantee that (1) The only + * domain used by Gen1 VMs for something that looks like a physical + * PCI bus (which is actually emulated by the hypervisor) is domain 0. + * (2) There will be no overlap between domains (after fixing possible + * collisions) in the same VM. + */ + dom_req = hdev->dev_instance.b[5] << 8 | hdev->dev_instance.b[4]; + dom = hv_get_dom_num(dom_req); + + if (dom == HVPCI_DOM_INVALID) { + dev_err(&hdev->device, + "Unable to use dom# 0x%x or other numbers", dom_req); + ret = -EINVAL; + goto free_bus; + } + + if (dom != dom_req) + dev_info(&hdev->device, + "PCI dom# 0x%x has collision, using 0x%x", + dom_req, dom); + + hbus->bridge->domain_nr = dom; +#ifdef CONFIG_X86 + hbus->sysdata.domain = dom; +#elif defined(CONFIG_ARM64) + /* + * Set the PCI bus parent to be the corresponding VMbus + * device. Then the VMbus device will be assigned as the + * ACPI companion in pcibios_root_bridge_prepare() and + * pci_dma_configure() will propagate device coherence + * information to devices created on the bus. + */ + hbus->sysdata.parent = hdev->device.parent; +#endif + + hbus->hdev = hdev; + INIT_LIST_HEAD(&hbus->children); + INIT_LIST_HEAD(&hbus->dr_list); + spin_lock_init(&hbus->config_lock); + spin_lock_init(&hbus->device_list_lock); + spin_lock_init(&hbus->retarget_msi_interrupt_lock); + hbus->wq = alloc_ordered_workqueue("hv_pci_%x", 0, + hbus->bridge->domain_nr); + if (!hbus->wq) { + ret = -ENOMEM; + goto free_dom; + } + + hdev->channel->next_request_id_callback = vmbus_next_request_id; + hdev->channel->request_addr_callback = vmbus_request_addr; + hdev->channel->rqstor_size = HV_PCI_RQSTOR_SIZE; + + ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0, + hv_pci_onchannelcallback, hbus); + if (ret) + goto destroy_wq; + + hv_set_drvdata(hdev, hbus); + + ret = hv_pci_protocol_negotiation(hdev, pci_protocol_versions, + ARRAY_SIZE(pci_protocol_versions)); + if (ret) + goto close; + + ret = hv_allocate_config_window(hbus); + if (ret) + goto close; + + hbus->cfg_addr = ioremap(hbus->mem_config->start, + PCI_CONFIG_MMIO_LENGTH); + if (!hbus->cfg_addr) { + dev_err(&hdev->device, + "Unable to map a virtual address for config space\n"); + ret = -ENOMEM; + goto free_config; + } + + name = kasprintf(GFP_KERNEL, "%pUL", &hdev->dev_instance); + if (!name) { + ret = -ENOMEM; + goto unmap; + } + + hbus->fwnode = irq_domain_alloc_named_fwnode(name); + kfree(name); + if (!hbus->fwnode) { + ret = -ENOMEM; + goto unmap; + } + + ret = hv_pcie_init_irq_domain(hbus); + if (ret) + goto free_fwnode; + + ret = hv_pci_query_relations(hdev); + if (ret) + goto free_irq_domain; + + mutex_lock(&hbus->state_lock); + + ret = hv_pci_enter_d0(hdev); + if (ret) + goto release_state_lock; + + ret = hv_pci_allocate_bridge_windows(hbus); + if (ret) + goto exit_d0; + + ret = hv_send_resources_allocated(hdev); + if (ret) + goto free_windows; + + prepopulate_bars(hbus); + + hbus->state = hv_pcibus_probed; + + ret = create_root_hv_pci_bus(hbus); + if (ret) + goto free_windows; + + mutex_unlock(&hbus->state_lock); + return 0; + +free_windows: + hv_pci_free_bridge_windows(hbus); +exit_d0: + (void) hv_pci_bus_exit(hdev, true); +release_state_lock: + mutex_unlock(&hbus->state_lock); +free_irq_domain: + irq_domain_remove(hbus->irq_domain); +free_fwnode: + irq_domain_free_fwnode(hbus->fwnode); +unmap: + iounmap(hbus->cfg_addr); +free_config: + hv_free_config_window(hbus); +close: + vmbus_close(hdev->channel); +destroy_wq: + destroy_workqueue(hbus->wq); +free_dom: + hv_put_dom_num(hbus->bridge->domain_nr); +free_bus: + kfree(hbus); + return ret; +} + +static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs) +{ + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); + struct vmbus_channel *chan = hdev->channel; + struct { + struct pci_packet teardown_packet; + u8 buffer[sizeof(struct pci_message)]; + } pkt; + struct hv_pci_compl comp_pkt; + struct hv_pci_dev *hpdev, *tmp; + unsigned long flags; + u64 trans_id; + int ret; + + /* + * After the host sends the RESCIND_CHANNEL message, it doesn't + * access the per-channel ringbuffer any longer. + */ + if (chan->rescind) + return 0; + + if (!keep_devs) { + struct list_head removed; + + /* Move all present children to the list on stack */ + INIT_LIST_HEAD(&removed); + spin_lock_irqsave(&hbus->device_list_lock, flags); + list_for_each_entry_safe(hpdev, tmp, &hbus->children, list_entry) + list_move_tail(&hpdev->list_entry, &removed); + spin_unlock_irqrestore(&hbus->device_list_lock, flags); + + /* Remove all children in the list */ + list_for_each_entry_safe(hpdev, tmp, &removed, list_entry) { + list_del(&hpdev->list_entry); + if (hpdev->pci_slot) + pci_destroy_slot(hpdev->pci_slot); + /* For the two refs got in new_pcichild_device() */ + put_pcichild(hpdev); + put_pcichild(hpdev); + } + } + + ret = hv_send_resources_released(hdev); + if (ret) { + dev_err(&hdev->device, + "Couldn't send resources released packet(s)\n"); + return ret; + } + + memset(&pkt.teardown_packet, 0, sizeof(pkt.teardown_packet)); + init_completion(&comp_pkt.host_event); + pkt.teardown_packet.completion_func = hv_pci_generic_compl; + pkt.teardown_packet.compl_ctxt = &comp_pkt; + pkt.teardown_packet.message[0].type = PCI_BUS_D0EXIT; + + ret = vmbus_sendpacket_getid(chan, &pkt.teardown_packet.message, + sizeof(struct pci_message), + (unsigned long)&pkt.teardown_packet, + &trans_id, VM_PKT_DATA_INBAND, + VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); + if (ret) + return ret; + + if (wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ) == 0) { + /* + * The completion packet on the stack becomes invalid after + * 'return'; remove the ID from the VMbus requestor if the + * identifier is still mapped to/associated with the packet. + * + * Cf. hv_pci_onchannelcallback(). + */ + vmbus_request_addr_match(chan, trans_id, + (unsigned long)&pkt.teardown_packet); + return -ETIMEDOUT; + } + + return 0; +} + +/** + * hv_pci_remove() - Remove routine for this VMBus channel + * @hdev: VMBus's tracking struct for this root PCI bus + * + * Return: 0 on success, -errno on failure + */ +static int hv_pci_remove(struct hv_device *hdev) +{ + struct hv_pcibus_device *hbus; + int ret; + + hbus = hv_get_drvdata(hdev); + if (hbus->state == hv_pcibus_installed) { + tasklet_disable(&hdev->channel->callback_event); + hbus->state = hv_pcibus_removing; + tasklet_enable(&hdev->channel->callback_event); + destroy_workqueue(hbus->wq); + hbus->wq = NULL; + /* + * At this point, no work is running or can be scheduled + * on hbus-wq. We can't race with hv_pci_devices_present() + * or hv_pci_eject_device(), it's safe to proceed. + */ + + /* Remove the bus from PCI's point of view. */ + pci_lock_rescan_remove(); + pci_stop_root_bus(hbus->bridge->bus); + hv_pci_remove_slots(hbus); + pci_remove_root_bus(hbus->bridge->bus); + pci_unlock_rescan_remove(); + } + + ret = hv_pci_bus_exit(hdev, false); + + vmbus_close(hdev->channel); + + iounmap(hbus->cfg_addr); + hv_free_config_window(hbus); + hv_pci_free_bridge_windows(hbus); + irq_domain_remove(hbus->irq_domain); + irq_domain_free_fwnode(hbus->fwnode); + + hv_put_dom_num(hbus->bridge->domain_nr); + + kfree(hbus); + return ret; +} + +static int hv_pci_suspend(struct hv_device *hdev) +{ + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); + enum hv_pcibus_state old_state; + int ret; + + /* + * hv_pci_suspend() must make sure there are no pending work items + * before calling vmbus_close(), since it runs in a process context + * as a callback in dpm_suspend(). When it starts to run, the channel + * callback hv_pci_onchannelcallback(), which runs in a tasklet + * context, can be still running concurrently and scheduling new work + * items onto hbus->wq in hv_pci_devices_present() and + * hv_pci_eject_device(), and the work item handlers can access the + * vmbus channel, which can be being closed by hv_pci_suspend(), e.g. + * the work item handler pci_devices_present_work() -> + * new_pcichild_device() writes to the vmbus channel. + * + * To eliminate the race, hv_pci_suspend() disables the channel + * callback tasklet, sets hbus->state to hv_pcibus_removing, and + * re-enables the tasklet. This way, when hv_pci_suspend() proceeds, + * it knows that no new work item can be scheduled, and then it flushes + * hbus->wq and safely closes the vmbus channel. + */ + tasklet_disable(&hdev->channel->callback_event); + + /* Change the hbus state to prevent new work items. */ + old_state = hbus->state; + if (hbus->state == hv_pcibus_installed) + hbus->state = hv_pcibus_removing; + + tasklet_enable(&hdev->channel->callback_event); + + if (old_state != hv_pcibus_installed) + return -EINVAL; + + flush_workqueue(hbus->wq); + + ret = hv_pci_bus_exit(hdev, true); + if (ret) + return ret; + + vmbus_close(hdev->channel); + + return 0; +} + +static int hv_pci_restore_msi_msg(struct pci_dev *pdev, void *arg) +{ + struct irq_data *irq_data; + struct msi_desc *entry; + int ret = 0; + + if (!pdev->msi_enabled && !pdev->msix_enabled) + return 0; + + msi_lock_descs(&pdev->dev); + msi_for_each_desc(entry, &pdev->dev, MSI_DESC_ASSOCIATED) { + irq_data = irq_get_irq_data(entry->irq); + if (WARN_ON_ONCE(!irq_data)) { + ret = -EINVAL; + break; + } + + hv_compose_msi_msg(irq_data, &entry->msg); + } + msi_unlock_descs(&pdev->dev); + + return ret; +} + +/* + * Upon resume, pci_restore_msi_state() -> ... -> __pci_write_msi_msg() + * directly writes the MSI/MSI-X registers via MMIO, but since Hyper-V + * doesn't trap and emulate the MMIO accesses, here hv_compose_msi_msg() + * must be used to ask Hyper-V to re-create the IOMMU Interrupt Remapping + * Table entries. + */ +static void hv_pci_restore_msi_state(struct hv_pcibus_device *hbus) +{ + pci_walk_bus(hbus->bridge->bus, hv_pci_restore_msi_msg, NULL); +} + +static int hv_pci_resume(struct hv_device *hdev) +{ + struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); + enum pci_protocol_version_t version[1]; + int ret; + + hbus->state = hv_pcibus_init; + + hdev->channel->next_request_id_callback = vmbus_next_request_id; + hdev->channel->request_addr_callback = vmbus_request_addr; + hdev->channel->rqstor_size = HV_PCI_RQSTOR_SIZE; + + ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0, + hv_pci_onchannelcallback, hbus); + if (ret) + return ret; + + /* Only use the version that was in use before hibernation. */ + version[0] = hbus->protocol_version; + ret = hv_pci_protocol_negotiation(hdev, version, 1); + if (ret) + goto out; + + ret = hv_pci_query_relations(hdev); + if (ret) + goto out; + + mutex_lock(&hbus->state_lock); + + ret = hv_pci_enter_d0(hdev); + if (ret) + goto release_state_lock; + + ret = hv_send_resources_allocated(hdev); + if (ret) + goto release_state_lock; + + prepopulate_bars(hbus); + + hv_pci_restore_msi_state(hbus); + + hbus->state = hv_pcibus_installed; + mutex_unlock(&hbus->state_lock); + return 0; + +release_state_lock: + mutex_unlock(&hbus->state_lock); +out: + vmbus_close(hdev->channel); + return ret; +} + +static const struct hv_vmbus_device_id hv_pci_id_table[] = { + /* PCI Pass-through Class ID */ + /* 44C4F61D-4444-4400-9D52-802E27EDE19F */ + { HV_PCIE_GUID, }, + { }, +}; + +MODULE_DEVICE_TABLE(vmbus, hv_pci_id_table); + +static struct hv_driver hv_pci_drv = { + .name = "hv_pci", + .id_table = hv_pci_id_table, + .probe = hv_pci_probe, + .remove = hv_pci_remove, + .suspend = hv_pci_suspend, + .resume = hv_pci_resume, +}; + +static void __exit exit_hv_pci_drv(void) +{ + vmbus_driver_unregister(&hv_pci_drv); + + hvpci_block_ops.read_block = NULL; + hvpci_block_ops.write_block = NULL; + hvpci_block_ops.reg_blk_invalidate = NULL; +} + +static int __init init_hv_pci_drv(void) +{ + int ret; + + if (!hv_is_hyperv_initialized()) + return -ENODEV; + + ret = hv_pci_irqchip_init(); + if (ret) + return ret; + + /* Set the invalid domain number's bit, so it will not be used */ + set_bit(HVPCI_DOM_INVALID, hvpci_dom_map); + + /* Initialize PCI block r/w interface */ + hvpci_block_ops.read_block = hv_read_config_block; + hvpci_block_ops.write_block = hv_write_config_block; + hvpci_block_ops.reg_blk_invalidate = hv_register_block_invalidate; + + return vmbus_driver_register(&hv_pci_drv); +} + +module_init(init_hv_pci_drv); +module_exit(exit_hv_pci_drv); + +MODULE_DESCRIPTION("Hyper-V PCI"); +MODULE_LICENSE("GPL v2"); |