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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/kernel/apic/msi.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/kernel/apic/msi.c')
-rw-r--r-- | arch/x86/kernel/apic/msi.c | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c new file mode 100644 index 000000000..ab348aec8 --- /dev/null +++ b/arch/x86/kernel/apic/msi.c @@ -0,0 +1,348 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Support of MSI, HPET and DMAR interrupts. + * + * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo + * Moved from arch/x86/kernel/apic/io_apic.c. + * Jiang Liu <jiang.liu@linux.intel.com> + * Convert to hierarchical irqdomain + */ +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/pci.h> +#include <linux/dmar.h> +#include <linux/hpet.h> +#include <linux/msi.h> +#include <asm/irqdomain.h> +#include <asm/hpet.h> +#include <asm/hw_irq.h> +#include <asm/apic.h> +#include <asm/irq_remapping.h> +#include <asm/xen/hypervisor.h> + +struct irq_domain *x86_pci_msi_default_domain __ro_after_init; + +static void irq_msi_update_msg(struct irq_data *irqd, struct irq_cfg *cfg) +{ + struct msi_msg msg[2] = { [1] = { }, }; + + __irq_msi_compose_msg(cfg, msg, false); + irq_data_get_irq_chip(irqd)->irq_write_msi_msg(irqd, msg); +} + +static int +msi_set_affinity(struct irq_data *irqd, const struct cpumask *mask, bool force) +{ + struct irq_cfg old_cfg, *cfg = irqd_cfg(irqd); + struct irq_data *parent = irqd->parent_data; + unsigned int cpu; + int ret; + + /* Save the current configuration */ + cpu = cpumask_first(irq_data_get_effective_affinity_mask(irqd)); + old_cfg = *cfg; + + /* Allocate a new target vector */ + ret = parent->chip->irq_set_affinity(parent, mask, force); + if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE) + return ret; + + /* + * For non-maskable and non-remapped MSI interrupts the migration + * to a different destination CPU and a different vector has to be + * done careful to handle the possible stray interrupt which can be + * caused by the non-atomic update of the address/data pair. + * + * Direct update is possible when: + * - The MSI is maskable (remapped MSI does not use this code path). + * The reservation mode bit is set in this case. + * - The new vector is the same as the old vector + * - The old vector is MANAGED_IRQ_SHUTDOWN_VECTOR (interrupt starts up) + * - The interrupt is not yet started up + * - The new destination CPU is the same as the old destination CPU + */ + if (!irqd_can_reserve(irqd) || + cfg->vector == old_cfg.vector || + old_cfg.vector == MANAGED_IRQ_SHUTDOWN_VECTOR || + !irqd_is_started(irqd) || + cfg->dest_apicid == old_cfg.dest_apicid) { + irq_msi_update_msg(irqd, cfg); + return ret; + } + + /* + * Paranoia: Validate that the interrupt target is the local + * CPU. + */ + if (WARN_ON_ONCE(cpu != smp_processor_id())) { + irq_msi_update_msg(irqd, cfg); + return ret; + } + + /* + * Redirect the interrupt to the new vector on the current CPU + * first. This might cause a spurious interrupt on this vector if + * the device raises an interrupt right between this update and the + * update to the final destination CPU. + * + * If the vector is in use then the installed device handler will + * denote it as spurious which is no harm as this is a rare event + * and interrupt handlers have to cope with spurious interrupts + * anyway. If the vector is unused, then it is marked so it won't + * trigger the 'No irq handler for vector' warning in + * common_interrupt(). + * + * This requires to hold vector lock to prevent concurrent updates to + * the affected vector. + */ + lock_vector_lock(); + + /* + * Mark the new target vector on the local CPU if it is currently + * unused. Reuse the VECTOR_RETRIGGERED state which is also used in + * the CPU hotplug path for a similar purpose. This cannot be + * undone here as the current CPU has interrupts disabled and + * cannot handle the interrupt before the whole set_affinity() + * section is done. In the CPU unplug case, the current CPU is + * about to vanish and will not handle any interrupts anymore. The + * vector is cleaned up when the CPU comes online again. + */ + if (IS_ERR_OR_NULL(this_cpu_read(vector_irq[cfg->vector]))) + this_cpu_write(vector_irq[cfg->vector], VECTOR_RETRIGGERED); + + /* Redirect it to the new vector on the local CPU temporarily */ + old_cfg.vector = cfg->vector; + irq_msi_update_msg(irqd, &old_cfg); + + /* Now transition it to the target CPU */ + irq_msi_update_msg(irqd, cfg); + + /* + * All interrupts after this point are now targeted at the new + * vector/CPU. + * + * Drop vector lock before testing whether the temporary assignment + * to the local CPU was hit by an interrupt raised in the device, + * because the retrigger function acquires vector lock again. + */ + unlock_vector_lock(); + + /* + * Check whether the transition raced with a device interrupt and + * is pending in the local APICs IRR. It is safe to do this outside + * of vector lock as the irq_desc::lock of this interrupt is still + * held and interrupts are disabled: The check is not accessing the + * underlying vector store. It's just checking the local APIC's + * IRR. + */ + if (lapic_vector_set_in_irr(cfg->vector)) + irq_data_get_irq_chip(irqd)->irq_retrigger(irqd); + + return ret; +} + +/* + * IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices, + * which implement the MSI or MSI-X Capability Structure. + */ +static struct irq_chip pci_msi_controller = { + .name = "PCI-MSI", + .irq_unmask = pci_msi_unmask_irq, + .irq_mask = pci_msi_mask_irq, + .irq_ack = irq_chip_ack_parent, + .irq_retrigger = irq_chip_retrigger_hierarchy, + .irq_set_affinity = msi_set_affinity, + .flags = IRQCHIP_SKIP_SET_WAKE | + IRQCHIP_AFFINITY_PRE_STARTUP, +}; + +int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec, + msi_alloc_info_t *arg) +{ + init_irq_alloc_info(arg, NULL); + if (to_pci_dev(dev)->msix_enabled) { + arg->type = X86_IRQ_ALLOC_TYPE_PCI_MSIX; + } else { + arg->type = X86_IRQ_ALLOC_TYPE_PCI_MSI; + arg->flags |= X86_IRQ_ALLOC_CONTIGUOUS_VECTORS; + } + + return 0; +} +EXPORT_SYMBOL_GPL(pci_msi_prepare); + +static struct msi_domain_ops pci_msi_domain_ops = { + .msi_prepare = pci_msi_prepare, +}; + +static struct msi_domain_info pci_msi_domain_info = { + .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | + MSI_FLAG_PCI_MSIX, + .ops = &pci_msi_domain_ops, + .chip = &pci_msi_controller, + .handler = handle_edge_irq, + .handler_name = "edge", +}; + +struct irq_domain * __init native_create_pci_msi_domain(void) +{ + struct fwnode_handle *fn; + struct irq_domain *d; + + if (disable_apic) + return NULL; + + fn = irq_domain_alloc_named_fwnode("PCI-MSI"); + if (!fn) + return NULL; + + d = pci_msi_create_irq_domain(fn, &pci_msi_domain_info, + x86_vector_domain); + if (!d) { + irq_domain_free_fwnode(fn); + pr_warn("Failed to initialize PCI-MSI irqdomain.\n"); + } + return d; +} + +void __init x86_create_pci_msi_domain(void) +{ + x86_pci_msi_default_domain = x86_init.irqs.create_pci_msi_domain(); +} + +#ifdef CONFIG_IRQ_REMAP +static struct irq_chip pci_msi_ir_controller = { + .name = "IR-PCI-MSI", + .irq_unmask = pci_msi_unmask_irq, + .irq_mask = pci_msi_mask_irq, + .irq_ack = irq_chip_ack_parent, + .irq_retrigger = irq_chip_retrigger_hierarchy, + .flags = IRQCHIP_SKIP_SET_WAKE | + IRQCHIP_AFFINITY_PRE_STARTUP, +}; + +static struct msi_domain_info pci_msi_ir_domain_info = { + .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | + MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX, + .ops = &pci_msi_domain_ops, + .chip = &pci_msi_ir_controller, + .handler = handle_edge_irq, + .handler_name = "edge", +}; + +struct irq_domain *arch_create_remap_msi_irq_domain(struct irq_domain *parent, + const char *name, int id) +{ + struct fwnode_handle *fn; + struct irq_domain *d; + + fn = irq_domain_alloc_named_id_fwnode(name, id); + if (!fn) + return NULL; + d = pci_msi_create_irq_domain(fn, &pci_msi_ir_domain_info, parent); + if (!d) + irq_domain_free_fwnode(fn); + return d; +} +#endif + +#ifdef CONFIG_DMAR_TABLE +/* + * The Intel IOMMU (ab)uses the high bits of the MSI address to contain the + * high bits of the destination APIC ID. This can't be done in the general + * case for MSIs as it would be targeting real memory above 4GiB not the + * APIC. + */ +static void dmar_msi_compose_msg(struct irq_data *data, struct msi_msg *msg) +{ + __irq_msi_compose_msg(irqd_cfg(data), msg, true); +} + +static void dmar_msi_write_msg(struct irq_data *data, struct msi_msg *msg) +{ + dmar_msi_write(data->irq, msg); +} + +static struct irq_chip dmar_msi_controller = { + .name = "DMAR-MSI", + .irq_unmask = dmar_msi_unmask, + .irq_mask = dmar_msi_mask, + .irq_ack = irq_chip_ack_parent, + .irq_set_affinity = msi_domain_set_affinity, + .irq_retrigger = irq_chip_retrigger_hierarchy, + .irq_compose_msi_msg = dmar_msi_compose_msg, + .irq_write_msi_msg = dmar_msi_write_msg, + .flags = IRQCHIP_SKIP_SET_WAKE | + IRQCHIP_AFFINITY_PRE_STARTUP, +}; + +static int dmar_msi_init(struct irq_domain *domain, + struct msi_domain_info *info, unsigned int virq, + irq_hw_number_t hwirq, msi_alloc_info_t *arg) +{ + irq_domain_set_info(domain, virq, arg->devid, info->chip, NULL, + handle_edge_irq, arg->data, "edge"); + + return 0; +} + +static struct msi_domain_ops dmar_msi_domain_ops = { + .msi_init = dmar_msi_init, +}; + +static struct msi_domain_info dmar_msi_domain_info = { + .ops = &dmar_msi_domain_ops, + .chip = &dmar_msi_controller, + .flags = MSI_FLAG_USE_DEF_DOM_OPS, +}; + +static struct irq_domain *dmar_get_irq_domain(void) +{ + static struct irq_domain *dmar_domain; + static DEFINE_MUTEX(dmar_lock); + struct fwnode_handle *fn; + + mutex_lock(&dmar_lock); + if (dmar_domain) + goto out; + + fn = irq_domain_alloc_named_fwnode("DMAR-MSI"); + if (fn) { + dmar_domain = msi_create_irq_domain(fn, &dmar_msi_domain_info, + x86_vector_domain); + if (!dmar_domain) + irq_domain_free_fwnode(fn); + } +out: + mutex_unlock(&dmar_lock); + return dmar_domain; +} + +int dmar_alloc_hwirq(int id, int node, void *arg) +{ + struct irq_domain *domain = dmar_get_irq_domain(); + struct irq_alloc_info info; + + if (!domain) + return -1; + + init_irq_alloc_info(&info, NULL); + info.type = X86_IRQ_ALLOC_TYPE_DMAR; + info.devid = id; + info.hwirq = id; + info.data = arg; + + return irq_domain_alloc_irqs(domain, 1, node, &info); +} + +void dmar_free_hwirq(int irq) +{ + irq_domain_free_irqs(irq, 1); +} +#endif + +bool arch_restore_msi_irqs(struct pci_dev *dev) +{ + return xen_initdom_restore_msi(dev); +} |