summaryrefslogtreecommitdiffstats
path: root/kernel/irq/msi.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--kernel/irq/msi.c559
1 files changed, 559 insertions, 0 deletions
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
new file mode 100644
index 000000000..4457f3e96
--- /dev/null
+++ b/kernel/irq/msi.c
@@ -0,0 +1,559 @@
+// 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 Signaled Interrupts 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 an affinity array[@nvec] is allocated
+ * and the affinity masks and flags from @affinity are copied.
+ */
+struct msi_desc *alloc_msi_entry(struct device *dev, int nvec,
+ const struct irq_affinity_desc *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,
+};
+
+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;
+}
+
+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,
+ .domain_alloc_irqs = __msi_domain_alloc_irqs,
+ .domain_free_irqs = __msi_domain_free_irqs,
+};
+
+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->domain_alloc_irqs == NULL)
+ ops->domain_alloc_irqs = msi_domain_ops_default.domain_alloc_irqs;
+ if (ops->domain_free_irqs == NULL)
+ ops->domain_free_irqs = msi_domain_ops_default.domain_free_irqs;
+
+ if (!(info->flags & MSI_FLAG_USE_DEF_DOM_OPS))
+ 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;
+
+ 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;
+
+ switch(domain->bus_token) {
+ case DOMAIN_BUS_PCI_MSI:
+ case DOMAIN_BUS_VMD_MSI:
+ break;
+ default:
+ 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;
+}
+
+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);
+ if ((info->flags & MSI_FLAG_ACTIVATE_EARLY) &&
+ irqd_affinity_is_managed(irq_data) &&
+ !cpumask_intersects(irq_data_get_affinity_mask(irq_data),
+ cpu_online_mask)) {
+ irqd_set_managed_shutdown(irq_data);
+ continue;
+ }
+ }
+ 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_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;
+
+ return ops->domain_alloc_irqs(domain, dev, nvec);
+}
+
+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_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 msi_domain_info *info = domain->host_data;
+ struct msi_domain_ops *ops = info->ops;
+
+ return ops->domain_free_irqs(domain, dev);
+}
+
+/**
+ * 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 */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 03:43:01 +0000