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/*
* linux/kernel/irq/msi.c
*
* 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);
}
/**
* 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;
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));
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;
BUG_ON(irq_chip_compose_msi_msg(irq_data, &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;
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);
for_each_msi_entry(desc, dev) {
virq = desc->irq;
if (desc->nvec_used == 1)
dev_dbg(dev, "irq %d for MSI\n", virq);
else
dev_dbg(dev, "irq [%d-%d] for MSI\n",
virq, virq + desc->nvec_used - 1);
/*
* 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))
continue;
irq_data = irq_domain_get_irq_data(domain, desc->irq);
if (!can_reserve)
irqd_clr_can_reserve(irq_data);
ret = irq_domain_activate_irq(irq_data, can_reserve);
if (ret)
goto cleanup;
}
/*
* If these interrupts use reservation mode, clear the activated bit
* so request_irq() will assign the final vector.
*/
if (can_reserve) {
for_each_msi_entry(desc, dev) {
irq_data = irq_domain_get_irq_data(domain, desc->irq);
irqd_clr_activated(irq_data);
}
}
return 0;
cleanup:
for_each_msi_entry(desc, dev) {
struct irq_data *irqd;
if (desc->irq == virq)
break;
irqd = irq_domain_get_irq_data(domain, desc->irq);
if (irqd_is_activated(irqd))
irq_domain_deactivate_irq(irqd);
}
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 msi_desc *desc;
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 */