diff options
Diffstat (limited to 'kernel/irq/msi.c')
| -rw-r--r-- | kernel/irq/msi.c | 527 |
1 files changed, 527 insertions, 0 deletions
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c new file mode 100644 index 000000000..88269dd5a --- /dev/null +++ b/kernel/irq/msi.c @@ -0,0 +1,527 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2014 Intel Corp. + * Author: Jiang Liu <jiang.liu@linux.intel.com> + * + * This file is licensed under GPLv2. + * + * This file contains common code to support Message Signalled Interrupt for + * PCI compatible and non PCI compatible devices. + */ +#include <linux/types.h> +#include <linux/device.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/msi.h> +#include <linux/slab.h> + +#include "internals.h" + +/** + * alloc_msi_entry - Allocate an initialize msi_entry + * @dev: Pointer to the device for which this is allocated + * @nvec: The number of vectors used in this entry + * @affinity: Optional pointer to an affinity mask array size of @nvec + * + * If @affinity is not NULL then a an affinity array[@nvec] is allocated + * and the affinity masks from @affinity are copied. + */ +struct msi_desc * +alloc_msi_entry(struct device *dev, int nvec, const struct cpumask *affinity) +{ + struct msi_desc *desc; + + desc = kzalloc(sizeof(*desc), GFP_KERNEL); + if (!desc) + return NULL; + + INIT_LIST_HEAD(&desc->list); + desc->dev = dev; + desc->nvec_used = nvec; + if (affinity) { + desc->affinity = kmemdup(affinity, + nvec * sizeof(*desc->affinity), GFP_KERNEL); + if (!desc->affinity) { + kfree(desc); + return NULL; + } + } + + return desc; +} + +void free_msi_entry(struct msi_desc *entry) +{ + kfree(entry->affinity); + kfree(entry); +} + +void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg) +{ + *msg = entry->msg; +} + +void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg) +{ + struct msi_desc *entry = irq_get_msi_desc(irq); + + __get_cached_msi_msg(entry, msg); +} +EXPORT_SYMBOL_GPL(get_cached_msi_msg); + +#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN +static inline void irq_chip_write_msi_msg(struct irq_data *data, + struct msi_msg *msg) +{ + data->chip->irq_write_msi_msg(data, msg); +} + +static void msi_check_level(struct irq_domain *domain, struct msi_msg *msg) +{ + struct msi_domain_info *info = domain->host_data; + + /* + * If the MSI provider has messed with the second message and + * not advertized that it is level-capable, signal the breakage. + */ + WARN_ON(!((info->flags & MSI_FLAG_LEVEL_CAPABLE) && + (info->chip->flags & IRQCHIP_SUPPORTS_LEVEL_MSI)) && + (msg[1].address_lo || msg[1].address_hi || msg[1].data)); +} + +/** + * msi_domain_set_affinity - Generic affinity setter function for MSI domains + * @irq_data: The irq data associated to the interrupt + * @mask: The affinity mask to set + * @force: Flag to enforce setting (disable online checks) + * + * Intended to be used by MSI interrupt controllers which are + * implemented with hierarchical domains. + */ +int msi_domain_set_affinity(struct irq_data *irq_data, + const struct cpumask *mask, bool force) +{ + struct irq_data *parent = irq_data->parent_data; + struct msi_msg msg[2] = { [1] = { }, }; + int ret; + + ret = parent->chip->irq_set_affinity(parent, mask, force); + if (ret >= 0 && ret != IRQ_SET_MASK_OK_DONE) { + BUG_ON(irq_chip_compose_msi_msg(irq_data, msg)); + msi_check_level(irq_data->domain, msg); + irq_chip_write_msi_msg(irq_data, msg); + } + + return ret; +} + +static int msi_domain_activate(struct irq_domain *domain, + struct irq_data *irq_data, bool early) +{ + struct msi_msg msg[2] = { [1] = { }, }; + + BUG_ON(irq_chip_compose_msi_msg(irq_data, msg)); + msi_check_level(irq_data->domain, msg); + irq_chip_write_msi_msg(irq_data, msg); + return 0; +} + +static void msi_domain_deactivate(struct irq_domain *domain, + struct irq_data *irq_data) +{ + struct msi_msg msg[2]; + + memset(msg, 0, sizeof(msg)); + irq_chip_write_msi_msg(irq_data, msg); +} + +static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs, void *arg) +{ + struct msi_domain_info *info = domain->host_data; + struct msi_domain_ops *ops = info->ops; + irq_hw_number_t hwirq = ops->get_hwirq(info, arg); + int i, ret; + + if (irq_find_mapping(domain, hwirq) > 0) + return -EEXIST; + + if (domain->parent) { + ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg); + if (ret < 0) + return ret; + } + + for (i = 0; i < nr_irqs; i++) { + ret = ops->msi_init(domain, info, virq + i, hwirq + i, arg); + if (ret < 0) { + if (ops->msi_free) { + for (i--; i > 0; i--) + ops->msi_free(domain, info, virq + i); + } + irq_domain_free_irqs_top(domain, virq, nr_irqs); + return ret; + } + } + + return 0; +} + +static void msi_domain_free(struct irq_domain *domain, unsigned int virq, + unsigned int nr_irqs) +{ + struct msi_domain_info *info = domain->host_data; + int i; + + if (info->ops->msi_free) { + for (i = 0; i < nr_irqs; i++) + info->ops->msi_free(domain, info, virq + i); + } + irq_domain_free_irqs_top(domain, virq, nr_irqs); +} + +static const struct irq_domain_ops msi_domain_ops = { + .alloc = msi_domain_alloc, + .free = msi_domain_free, + .activate = msi_domain_activate, + .deactivate = msi_domain_deactivate, +}; + +#ifdef GENERIC_MSI_DOMAIN_OPS +static irq_hw_number_t msi_domain_ops_get_hwirq(struct msi_domain_info *info, + msi_alloc_info_t *arg) +{ + return arg->hwirq; +} + +static int msi_domain_ops_prepare(struct irq_domain *domain, struct device *dev, + int nvec, msi_alloc_info_t *arg) +{ + memset(arg, 0, sizeof(*arg)); + return 0; +} + +static void msi_domain_ops_set_desc(msi_alloc_info_t *arg, + struct msi_desc *desc) +{ + arg->desc = desc; +} +#else +#define msi_domain_ops_get_hwirq NULL +#define msi_domain_ops_prepare NULL +#define msi_domain_ops_set_desc NULL +#endif /* !GENERIC_MSI_DOMAIN_OPS */ + +static int msi_domain_ops_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_hwirq_and_chip(domain, virq, hwirq, info->chip, + info->chip_data); + if (info->handler && info->handler_name) { + __irq_set_handler(virq, info->handler, 0, info->handler_name); + if (info->handler_data) + irq_set_handler_data(virq, info->handler_data); + } + return 0; +} + +static int msi_domain_ops_check(struct irq_domain *domain, + struct msi_domain_info *info, + struct device *dev) +{ + return 0; +} + +static struct msi_domain_ops msi_domain_ops_default = { + .get_hwirq = msi_domain_ops_get_hwirq, + .msi_init = msi_domain_ops_init, + .msi_check = msi_domain_ops_check, + .msi_prepare = msi_domain_ops_prepare, + .set_desc = msi_domain_ops_set_desc, +}; + +static void msi_domain_update_dom_ops(struct msi_domain_info *info) +{ + struct msi_domain_ops *ops = info->ops; + + if (ops == NULL) { + info->ops = &msi_domain_ops_default; + return; + } + + if (ops->get_hwirq == NULL) + ops->get_hwirq = msi_domain_ops_default.get_hwirq; + if (ops->msi_init == NULL) + ops->msi_init = msi_domain_ops_default.msi_init; + if (ops->msi_check == NULL) + ops->msi_check = msi_domain_ops_default.msi_check; + if (ops->msi_prepare == NULL) + ops->msi_prepare = msi_domain_ops_default.msi_prepare; + if (ops->set_desc == NULL) + ops->set_desc = msi_domain_ops_default.set_desc; +} + +static void msi_domain_update_chip_ops(struct msi_domain_info *info) +{ + struct irq_chip *chip = info->chip; + + BUG_ON(!chip || !chip->irq_mask || !chip->irq_unmask); + if (!chip->irq_set_affinity) + chip->irq_set_affinity = msi_domain_set_affinity; +} + +/** + * msi_create_irq_domain - Create a MSI interrupt domain + * @fwnode: Optional fwnode of the interrupt controller + * @info: MSI domain info + * @parent: Parent irq domain + */ +struct irq_domain *msi_create_irq_domain(struct fwnode_handle *fwnode, + struct msi_domain_info *info, + struct irq_domain *parent) +{ + struct irq_domain *domain; + + if (info->flags & MSI_FLAG_USE_DEF_DOM_OPS) + msi_domain_update_dom_ops(info); + if (info->flags & MSI_FLAG_USE_DEF_CHIP_OPS) + msi_domain_update_chip_ops(info); + + domain = irq_domain_create_hierarchy(parent, IRQ_DOMAIN_FLAG_MSI, 0, + fwnode, &msi_domain_ops, info); + + if (domain && !domain->name && info->chip) + domain->name = info->chip->name; + + return domain; +} + +int msi_domain_prepare_irqs(struct irq_domain *domain, struct device *dev, + int nvec, msi_alloc_info_t *arg) +{ + struct msi_domain_info *info = domain->host_data; + struct msi_domain_ops *ops = info->ops; + int ret; + + ret = ops->msi_check(domain, info, dev); + if (ret == 0) + ret = ops->msi_prepare(domain, dev, nvec, arg); + + return ret; +} + +int msi_domain_populate_irqs(struct irq_domain *domain, struct device *dev, + int virq, int nvec, msi_alloc_info_t *arg) +{ + struct msi_domain_info *info = domain->host_data; + struct msi_domain_ops *ops = info->ops; + struct msi_desc *desc; + int ret = 0; + + for_each_msi_entry(desc, dev) { + /* Don't even try the multi-MSI brain damage. */ + if (WARN_ON(!desc->irq || desc->nvec_used != 1)) { + ret = -EINVAL; + break; + } + + if (!(desc->irq >= virq && desc->irq < (virq + nvec))) + continue; + + ops->set_desc(arg, desc); + /* Assumes the domain mutex is held! */ + ret = irq_domain_alloc_irqs_hierarchy(domain, desc->irq, 1, + arg); + if (ret) + break; + + irq_set_msi_desc_off(desc->irq, 0, desc); + } + + if (ret) { + /* Mop up the damage */ + for_each_msi_entry(desc, dev) { + if (!(desc->irq >= virq && desc->irq < (virq + nvec))) + continue; + + irq_domain_free_irqs_common(domain, desc->irq, 1); + } + } + + return ret; +} + +/* + * Carefully check whether the device can use reservation mode. If + * reservation mode is enabled then the early activation will assign a + * dummy vector to the device. If the PCI/MSI device does not support + * masking of the entry then this can result in spurious interrupts when + * the device driver is not absolutely careful. But even then a malfunction + * of the hardware could result in a spurious interrupt on the dummy vector + * and render the device unusable. If the entry can be masked then the core + * logic will prevent the spurious interrupt and reservation mode can be + * used. For now reservation mode is restricted to PCI/MSI. + */ +static bool msi_check_reservation_mode(struct irq_domain *domain, + struct msi_domain_info *info, + struct device *dev) +{ + struct msi_desc *desc; + + if (domain->bus_token != DOMAIN_BUS_PCI_MSI) + return false; + + if (!(info->flags & MSI_FLAG_MUST_REACTIVATE)) + return false; + + if (IS_ENABLED(CONFIG_PCI_MSI) && pci_msi_ignore_mask) + return false; + + /* + * Checking the first MSI descriptor is sufficient. MSIX supports + * masking and MSI does so when the maskbit is set. + */ + desc = first_msi_entry(dev); + return desc->msi_attrib.is_msix || desc->msi_attrib.maskbit; +} + +/** + * msi_domain_alloc_irqs - Allocate interrupts from a MSI interrupt domain + * @domain: The domain to allocate from + * @dev: Pointer to device struct of the device for which the interrupts + * are allocated + * @nvec: The number of interrupts to allocate + * + * Returns 0 on success or an error code. + */ +int msi_domain_alloc_irqs(struct irq_domain *domain, struct device *dev, + int nvec) +{ + struct msi_domain_info *info = domain->host_data; + struct msi_domain_ops *ops = info->ops; + struct irq_data *irq_data; + struct msi_desc *desc; + msi_alloc_info_t arg; + int i, ret, virq; + bool can_reserve; + + ret = msi_domain_prepare_irqs(domain, dev, nvec, &arg); + if (ret) + return ret; + + for_each_msi_entry(desc, dev) { + ops->set_desc(&arg, desc); + + virq = __irq_domain_alloc_irqs(domain, -1, desc->nvec_used, + dev_to_node(dev), &arg, false, + desc->affinity); + if (virq < 0) { + ret = -ENOSPC; + if (ops->handle_error) + ret = ops->handle_error(domain, desc, ret); + if (ops->msi_finish) + ops->msi_finish(&arg, ret); + return ret; + } + + for (i = 0; i < desc->nvec_used; i++) { + irq_set_msi_desc_off(virq, i, desc); + irq_debugfs_copy_devname(virq + i, dev); + } + } + + if (ops->msi_finish) + ops->msi_finish(&arg, 0); + + can_reserve = msi_check_reservation_mode(domain, info, dev); + + /* + * This flag is set by the PCI layer as we need to activate + * the MSI entries before the PCI layer enables MSI in the + * card. Otherwise the card latches a random msi message. + */ + if (!(info->flags & MSI_FLAG_ACTIVATE_EARLY)) + goto skip_activate; + + for_each_msi_vector(desc, i, dev) { + if (desc->irq == i) { + virq = desc->irq; + dev_dbg(dev, "irq [%d-%d] for MSI\n", + virq, virq + desc->nvec_used - 1); + } + + irq_data = irq_domain_get_irq_data(domain, i); + if (!can_reserve) { + irqd_clr_can_reserve(irq_data); + if (domain->flags & IRQ_DOMAIN_MSI_NOMASK_QUIRK) + irqd_set_msi_nomask_quirk(irq_data); + } + ret = irq_domain_activate_irq(irq_data, can_reserve); + if (ret) + goto cleanup; + } + +skip_activate: + /* + * If these interrupts use reservation mode, clear the activated bit + * so request_irq() will assign the final vector. + */ + if (can_reserve) { + for_each_msi_vector(desc, i, dev) { + irq_data = irq_domain_get_irq_data(domain, i); + irqd_clr_activated(irq_data); + } + } + return 0; + +cleanup: + msi_domain_free_irqs(domain, dev); + return ret; +} + +/** + * msi_domain_free_irqs - Free interrupts from a MSI interrupt @domain associated tp @dev + * @domain: The domain to managing the interrupts + * @dev: Pointer to device struct of the device for which the interrupts + * are free + */ +void msi_domain_free_irqs(struct irq_domain *domain, struct device *dev) +{ + struct irq_data *irq_data; + struct msi_desc *desc; + int i; + + for_each_msi_vector(desc, i, dev) { + irq_data = irq_domain_get_irq_data(domain, i); + if (irqd_is_activated(irq_data)) + irq_domain_deactivate_irq(irq_data); + } + + for_each_msi_entry(desc, dev) { + /* + * We might have failed to allocate an MSI early + * enough that there is no IRQ associated to this + * entry. If that's the case, don't do anything. + */ + if (desc->irq) { + irq_domain_free_irqs(desc->irq, desc->nvec_used); + desc->irq = 0; + } + } +} + +/** + * msi_get_domain_info - Get the MSI interrupt domain info for @domain + * @domain: The interrupt domain to retrieve data from + * + * Returns the pointer to the msi_domain_info stored in + * @domain->host_data. + */ +struct msi_domain_info *msi_get_domain_info(struct irq_domain *domain) +{ + return (struct msi_domain_info *)domain->host_data; +} + +#endif /* CONFIG_GENERIC_MSI_IRQ_DOMAIN */ |