msi.c
// SPDX-License-Identifier: GPL-2.0
/*
* PCI Message Signaled Interrupt (MSI)
*
* Copyright (C) 2003-2004 Intel
* Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
* Copyright (C) 2016 Christoph Hellwig.
*/
#include <linux/err.h>
#include <linux/export.h>
#include <linux/irq.h>
#include "../pci.h"
#include "msi.h"
static int pci_msi_enable = 1;
int pci_msi_ignore_mask;
static noinline void pci_msi_update_mask(struct msi_desc *desc, u32 clear, u32 set)
{
raw_spinlock_t *lock = &to_pci_dev(desc->dev)->msi_lock;
unsigned long flags;
if (!desc->pci.msi_attrib.can_mask)
return;
raw_spin_lock_irqsave(lock, flags);
desc->pci.msi_mask &= ~clear;
desc->pci.msi_mask |= set;
pci_write_config_dword(msi_desc_to_pci_dev(desc), desc->pci.mask_pos,
desc->pci.msi_mask);
raw_spin_unlock_irqrestore(lock, flags);
}
static inline void pci_msi_mask(struct msi_desc *desc, u32 mask)
{
pci_msi_update_mask(desc, 0, mask);
}
static inline void pci_msi_unmask(struct msi_desc *desc, u32 mask)
{
pci_msi_update_mask(desc, mask, 0);
}
static inline void __iomem *pci_msix_desc_addr(struct msi_desc *desc)
{
return desc->pci.mask_base + desc->msi_index * PCI_MSIX_ENTRY_SIZE;
}
/*
* This internal function does not flush PCI writes to the device. All
* users must ensure that they read from the device before either assuming
* that the device state is up to date, or returning out of this file.
* It does not affect the msi_desc::msix_ctrl cache either. Use with care!
*/
static void pci_msix_write_vector_ctrl(struct msi_desc *desc, u32 ctrl)
{
void __iomem *desc_addr = pci_msix_desc_addr(desc);
if (desc->pci.msi_attrib.can_mask)
writel(ctrl, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
}
static inline void pci_msix_mask(struct msi_desc *desc)
{
desc->pci.msix_ctrl |= PCI_MSIX_ENTRY_CTRL_MASKBIT;
pci_msix_write_vector_ctrl(desc, desc->pci.msix_ctrl);
/* Flush write to device */
readl(desc->pci.mask_base);
}
static inline void pci_msix_unmask(struct msi_desc *desc)
{
desc->pci.msix_ctrl &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
pci_msix_write_vector_ctrl(desc, desc->pci.msix_ctrl);
}
static void __pci_msi_mask_desc(struct msi_desc *desc, u32 mask)
{
if (desc->pci.msi_attrib.is_msix)
pci_msix_mask(desc);
else
pci_msi_mask(desc, mask);
}
static void __pci_msi_unmask_desc(struct msi_desc *desc, u32 mask)
{
if (desc->pci.msi_attrib.is_msix)
pci_msix_unmask(desc);
else
pci_msi_unmask(desc, mask);
}
/**
* pci_msi_mask_irq - Generic IRQ chip callback to mask PCI/MSI interrupts
* @data: pointer to irqdata associated to that interrupt
*/
void pci_msi_mask_irq(struct irq_data *data)
{
struct msi_desc *desc = irq_data_get_msi_desc(data);
__pci_msi_mask_desc(desc, BIT(data->irq - desc->irq));
}
EXPORT_SYMBOL_GPL(pci_msi_mask_irq);
/**
* pci_msi_unmask_irq - Generic IRQ chip callback to unmask PCI/MSI interrupts
* @data: pointer to irqdata associated to that interrupt
*/
void pci_msi_unmask_irq(struct irq_data *data)
{
struct msi_desc *desc = irq_data_get_msi_desc(data);
__pci_msi_unmask_desc(desc, BIT(data->irq - desc->irq));
}
EXPORT_SYMBOL_GPL(pci_msi_unmask_irq);
void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
{
struct pci_dev *dev = msi_desc_to_pci_dev(entry);
BUG_ON(dev->current_state != PCI_D0);
if (entry->pci.msi_attrib.is_msix) {
void __iomem *base = pci_msix_desc_addr(entry);
if (WARN_ON_ONCE(entry->pci.msi_attrib.is_virtual))
return;
msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);
msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);
msg->data = readl(base + PCI_MSIX_ENTRY_DATA);
} else {
int pos = dev->msi_cap;
u16 data;
pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_LO,
&msg->address_lo);
if (entry->pci.msi_attrib.is_64) {
pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_HI,
&msg->address_hi);
pci_read_config_word(dev, pos + PCI_MSI_DATA_64, &data);
} else {
msg->address_hi = 0;
pci_read_config_word(dev, pos + PCI_MSI_DATA_32, &data);
}
msg->data = data;
}
}
void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
{
struct pci_dev *dev = msi_desc_to_pci_dev(entry);
if (dev->current_state != PCI_D0 || pci_dev_is_disconnected(dev)) {
/* Don't touch the hardware now */
} else if (entry->pci.msi_attrib.is_msix) {
void __iomem *base = pci_msix_desc_addr(entry);
u32 ctrl = entry->pci.msix_ctrl;
bool unmasked = !(ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT);
if (entry->pci.msi_attrib.is_virtual)
goto skip;
/*
* The specification mandates that the entry is masked
* when the message is modified:
*
* "If software changes the Address or Data value of an
* entry while the entry is unmasked, the result is
* undefined."
*/
if (unmasked)
pci_msix_write_vector_ctrl(entry, ctrl | PCI_MSIX_ENTRY_CTRL_MASKBIT);
writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR);
writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR);
writel(msg->data, base + PCI_MSIX_ENTRY_DATA);
if (unmasked)
pci_msix_write_vector_ctrl(entry, ctrl);
/* Ensure that the writes are visible in the device */
readl(base + PCI_MSIX_ENTRY_DATA);
} else {
int pos = dev->msi_cap;
u16 msgctl;
pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
msgctl &= ~PCI_MSI_FLAGS_QSIZE;
msgctl |= entry->pci.msi_attrib.multiple << 4;
pci_write_config_word(dev, pos + PCI_MSI_FLAGS, msgctl);
pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_LO,
msg->address_lo);
if (entry->pci.msi_attrib.is_64) {
pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_HI,
msg->address_hi);
pci_write_config_word(dev, pos + PCI_MSI_DATA_64,
msg->data);
} else {
pci_write_config_word(dev, pos + PCI_MSI_DATA_32,
msg->data);
}
/* Ensure that the writes are visible in the device */
pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
}
skip:
entry->msg = *msg;
if (entry->write_msi_msg)
entry->write_msi_msg(entry, entry->write_msi_msg_data);
}
void pci_write_msi_msg(unsigned int irq, struct msi_msg *msg)
{
struct msi_desc *entry = irq_get_msi_desc(irq);
__pci_write_msi_msg(entry, msg);
}
EXPORT_SYMBOL_GPL(pci_write_msi_msg);
static void free_msi_irqs(struct pci_dev *dev)
{
pci_msi_teardown_msi_irqs(dev);
if (dev->msix_base) {
iounmap(dev->msix_base);
dev->msix_base = NULL;
}
}
static void pci_intx_for_msi(struct pci_dev *dev, int enable)
{
if (!(dev->dev_flags & PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG))
pci_intx(dev, enable);
}
static void pci_msi_set_enable(struct pci_dev *dev, int enable)
{
u16 control;
pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
control &= ~PCI_MSI_FLAGS_ENABLE;
if (enable)
control |= PCI_MSI_FLAGS_ENABLE;
pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
}
/*
* Architecture override returns true when the PCI MSI message should be
* written by the generic restore function.
*/
bool __weak arch_restore_msi_irqs(struct pci_dev *dev)
{
return true;
}
static void __pci_restore_msi_state(struct pci_dev *dev)
{
struct msi_desc *entry;
u16 control;
if (!dev->msi_enabled)
return;
entry = irq_get_msi_desc(dev->irq);
pci_intx_for_msi(dev, 0);
pci_msi_set_enable(dev, 0);
if (arch_restore_msi_irqs(dev))
__pci_write_msi_msg(entry, &entry->msg);
pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
pci_msi_update_mask(entry, 0, 0);
control &= ~PCI_MSI_FLAGS_QSIZE;
control |= (entry->pci.msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE;
pci_write_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, control);
}
static void pci_msix_clear_and_set_ctrl(struct pci_dev *dev, u16 clear, u16 set)
{
u16 ctrl;
pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &ctrl);
ctrl &= ~clear;
ctrl |= set;
pci_write_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, ctrl);
}
static void __pci_restore_msix_state(struct pci_dev *dev)
{
struct msi_desc *entry;
bool write_msg;
if (!dev->msix_enabled)
return;
/* route the table */
pci_intx_for_msi(dev, 0);
pci_msix_clear_and_set_ctrl(dev, 0,
PCI_MSIX_FLAGS_ENABLE | PCI_MSIX_FLAGS_MASKALL);
write_msg = arch_restore_msi_irqs(dev);
msi_lock_descs(&dev->dev);
msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) {
if (write_msg)
__pci_write_msi_msg(entry, &entry->msg);
pci_msix_write_vector_ctrl(entry, entry->pci.msix_ctrl);
}
msi_unlock_descs(&dev->dev);
pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
}
void pci_restore_msi_state(struct pci_dev *dev)
{
__pci_restore_msi_state(dev);
__pci_restore_msix_state(dev);
}
EXPORT_SYMBOL_GPL(pci_restore_msi_state);
static void pcim_msi_release(void *pcidev)
{
struct pci_dev *dev = pcidev;
dev->is_msi_managed = false;
pci_free_irq_vectors(dev);
}
/*
* Needs to be separate from pcim_release to prevent an ordering problem
* vs. msi_device_data_release() in the MSI core code.
*/
static int pcim_setup_msi_release(struct pci_dev *dev)
{
int ret;
if (!pci_is_managed(dev) || dev->is_msi_managed)
return 0;
ret = devm_add_action(&dev->dev, pcim_msi_release, dev);
if (!ret)
dev->is_msi_managed = true;
return ret;
}
/*
* Ordering vs. devres: msi device data has to be installed first so that
* pcim_msi_release() is invoked before it on device release.
*/
static int pci_setup_msi_context(struct pci_dev *dev)
{
int ret = msi_setup_device_data(&dev->dev);
if (!ret)
ret = pcim_setup_msi_release(dev);
return ret;
}
static int msi_setup_msi_desc(struct pci_dev *dev, int nvec,
struct irq_affinity_desc *masks)
{
struct msi_desc desc;
u16 control;
/* MSI Entry Initialization */
memset(&desc, 0, sizeof(desc));
pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &control);
/* Lies, damned lies, and MSIs */
if (dev->dev_flags & PCI_DEV_FLAGS_HAS_MSI_MASKING)
control |= PCI_MSI_FLAGS_MASKBIT;
/* Respect XEN's mask disabling */
if (pci_msi_ignore_mask)
control &= ~PCI_MSI_FLAGS_MASKBIT;
desc.nvec_used = nvec;
desc.pci.msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT);
desc.pci.msi_attrib.can_mask = !!(control & PCI_MSI_FLAGS_MASKBIT);
desc.pci.msi_attrib.default_irq = dev->irq;
desc.pci.msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1;
desc.pci.msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec));
desc.affinity = masks;
if (control & PCI_MSI_FLAGS_64BIT)
desc.pci.mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
else
desc.pci.mask_pos = dev->msi_cap + PCI_MSI_MASK_32;
/* Save the initial mask status */
if (desc.pci.msi_attrib.can_mask)
pci_read_config_dword(dev, desc.pci.mask_pos, &desc.pci.msi_mask);
return msi_add_msi_desc(&dev->dev, &desc);
}
static int msi_verify_entries(struct pci_dev *dev)
{
struct msi_desc *entry;
if (!dev->no_64bit_msi)
return 0;
msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) {
if (entry->msg.address_hi) {
pci_err(dev, "arch assigned 64-bit MSI address %#x%08x but device only supports 32 bits\n",
entry->msg.address_hi, entry->msg.address_lo);
break;
}
}
return !entry ? 0 : -EIO;
}
/**
* msi_capability_init - configure device's MSI capability structure
* @dev: pointer to the pci_dev data structure of MSI device function
* @nvec: number of interrupts to allocate
* @affd: description of automatic IRQ affinity assignments (may be %NULL)
*
* Setup the MSI capability structure of the device with the requested
* number of interrupts. A return value of zero indicates the successful
* setup of an entry with the new MSI IRQ. A negative return value indicates
* an error, and a positive return value indicates the number of interrupts
* which could have been allocated.
*/
static int msi_capability_init(struct pci_dev *dev, int nvec,
struct irq_affinity *affd)
{
struct irq_affinity_desc *masks = NULL;
struct msi_desc *entry;
int ret;
/*
* Disable MSI during setup in the hardware, but mark it enabled
* so that setup code can evaluate it.
*/
pci_msi_set_enable(dev, 0);
dev->msi_enabled = 1;
if (affd)
masks = irq_create_affinity_masks(nvec, affd);
msi_lock_descs(&dev->dev);
ret = msi_setup_msi_desc(dev, nvec, masks);
if (ret)
goto fail;
/* All MSIs are unmasked by default; mask them all */
entry = msi_first_desc(&dev->dev, MSI_DESC_ALL);
pci_msi_mask(entry, msi_multi_mask(entry));
/* Configure MSI capability structure */
ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
if (ret)
goto err;
ret = msi_verify_entries(dev);
if (ret)
goto err;
/* Set MSI enabled bits */
pci_intx_for_msi(dev, 0);
pci_msi_set_enable(dev, 1);
pcibios_free_irq(dev);
dev->irq = entry->irq;
goto unlock;
err:
pci_msi_unmask(entry, msi_multi_mask(entry));
free_msi_irqs(dev);
fail:
dev->msi_enabled = 0;
unlock:
msi_unlock_descs(&dev->dev);
kfree(masks);
return ret;
}
static void __iomem *msix_map_region(struct pci_dev *dev,
unsigned int nr_entries)
{
resource_size_t phys_addr;
u32 table_offset;
unsigned long flags;
u8 bir;
pci_read_config_dword(dev, dev->msix_cap + PCI_MSIX_TABLE,
&table_offset);
bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
flags = pci_resource_flags(dev, bir);
if (!flags || (flags & IORESOURCE_UNSET))
return NULL;
table_offset &= PCI_MSIX_TABLE_OFFSET;
phys_addr = pci_resource_start(dev, bir) + table_offset;
return ioremap(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE);
}
static int msix_setup_msi_descs(struct pci_dev *dev, void __iomem *base,
struct msix_entry *entries, int nvec,
struct irq_affinity_desc *masks)
{
int ret = 0, i, vec_count = pci_msix_vec_count(dev);
struct irq_affinity_desc *curmsk;
struct msi_desc desc;
void __iomem *addr;
memset(&desc, 0, sizeof(desc));
desc.nvec_used = 1;
desc.pci.msi_attrib.is_msix = 1;
desc.pci.msi_attrib.is_64 = 1;
desc.pci.msi_attrib.default_irq = dev->irq;
desc.pci.mask_base = base;
for (i = 0, curmsk = masks; i < nvec; i++, curmsk++) {
desc.msi_index = entries ? entries[i].entry : i;
desc.affinity = masks ? curmsk : NULL;
desc.pci.msi_attrib.is_virtual = desc.msi_index >= vec_count;
desc.pci.msi_attrib.can_mask = !pci_msi_ignore_mask &&
!desc.pci.msi_attrib.is_virtual;
if (!desc.pci.msi_attrib.can_mask) {
addr = pci_msix_desc_addr(&desc);
desc.pci.msix_ctrl = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
}
ret = msi_add_msi_desc(&dev->dev, &desc);
if (ret)
break;
}
return ret;
}
static void msix_update_entries(struct pci_dev *dev, struct msix_entry *entries)
{
struct msi_desc *desc;
if (entries) {
msi_for_each_desc(desc, &dev->dev, MSI_DESC_ALL) {
entries->vector = desc->irq;
entries++;
}
}
}
static void msix_mask_all(void __iomem *base, int tsize)
{
u32 ctrl = PCI_MSIX_ENTRY_CTRL_MASKBIT;
int i;
if (pci_msi_ignore_mask)
return;
for (i = 0; i < tsize; i++, base += PCI_MSIX_ENTRY_SIZE)
writel(ctrl, base + PCI_MSIX_ENTRY_VECTOR_CTRL);
}
static int msix_setup_interrupts(struct pci_dev *dev, void __iomem *base,
struct msix_entry *entries, int nvec,
struct irq_affinity *affd)
{
struct irq_affinity_desc *masks = NULL;
int ret;
if (affd)
masks = irq_create_affinity_masks(nvec, affd);
msi_lock_descs(&dev->dev);
ret = msix_setup_msi_descs(dev, base, entries, nvec, masks);
if (ret)
goto out_free;
ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
if (ret)
goto out_free;
/* Check if all MSI entries honor device restrictions */
ret = msi_verify_entries(dev);
if (ret)
goto out_free;
msix_update_entries(dev, entries);
goto out_unlock;
out_free:
free_msi_irqs(dev);
out_unlock:
msi_unlock_descs(&dev->dev);
kfree(masks);
return ret;
}
/**
* msix_capability_init - configure device's MSI-X capability
* @dev: pointer to the pci_dev data structure of MSI-X device function
* @entries: pointer to an array of struct msix_entry entries
* @nvec: number of @entries
* @affd: Optional pointer to enable automatic affinity assignment
*
* Setup the MSI-X capability structure of device function with a
* single MSI-X IRQ. A return of zero indicates the successful setup of
* requested MSI-X entries with allocated IRQs or non-zero for otherwise.
**/
static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
int nvec, struct irq_affinity *affd)
{
void __iomem *base;
int ret, tsize;
u16 control;
/*
* Some devices require MSI-X to be enabled before the MSI-X
* registers can be accessed. Mask all the vectors to prevent
* interrupts coming in before they're fully set up.
*/
pci_msix_clear_and_set_ctrl(dev, 0, PCI_MSIX_FLAGS_MASKALL |
PCI_MSIX_FLAGS_ENABLE);
/* Mark it enabled so setup functions can query it */
dev->msix_enabled = 1;
pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
/* Request & Map MSI-X table region */
tsize = msix_table_size(control);
base = msix_map_region(dev, tsize);
if (!base) {
ret = -ENOMEM;
goto out_disable;
}
dev->msix_base = base;
ret = msix_setup_interrupts(dev, base, entries, nvec, affd);
if (ret)
goto out_disable;
/* Disable INTX */
pci_intx_for_msi(dev, 0);
/*
* Ensure that all table entries are masked to prevent
* stale entries from firing in a crash kernel.
*
* Done late to deal with a broken Marvell NVME device
* which takes the MSI-X mask bits into account even
* when MSI-X is disabled, which prevents MSI delivery.
*/
msix_mask_all(base, tsize);
pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
pcibios_free_irq(dev);
return 0;
out_disable:
dev->msix_enabled = 0;
pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE, 0);
return ret;
}
/**
* pci_msi_supported - check whether MSI may be enabled on a device
* @dev: pointer to the pci_dev data structure of MSI device function
* @nvec: how many MSIs have been requested?
*
* Look at global flags, the device itself, and its parent buses
* to determine if MSI/-X are supported for the device. If MSI/-X is
* supported return 1, else return 0.
**/
static int pci_msi_supported(struct pci_dev *dev, int nvec)
{
struct pci_bus *bus;
/* MSI must be globally enabled and supported by the device */
if (!pci_msi_enable)
return 0;
if (!dev || dev->no_msi)
return 0;
/*
* You can't ask to have 0 or less MSIs configured.
* a) it's stupid ..
* b) the list manipulation code assumes nvec >= 1.
*/
if (nvec < 1)
return 0;
/*
* Any bridge which does NOT route MSI transactions from its
* secondary bus to its primary bus must set NO_MSI flag on
* the secondary pci_bus.
*
* The NO_MSI flag can either be set directly by:
* - arch-specific PCI host bus controller drivers (deprecated)
* - quirks for specific PCI bridges
*
* or indirectly by platform-specific PCI host bridge drivers by
* advertising the 'msi_domain' property, which results in
* the NO_MSI flag when no MSI domain is found for this bridge
* at probe time.
*/
for (bus = dev->bus; bus; bus = bus->parent)
if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
return 0;
return 1;
}
/**
* pci_msi_vec_count - Return the number of MSI vectors a device can send
* @dev: device to report about
*
* This function returns the number of MSI vectors a device requested via
* Multiple Message Capable register. It returns a negative errno if the
* device is not capable sending MSI interrupts. Otherwise, the call succeeds
* and returns a power of two, up to a maximum of 2^5 (32), according to the
* MSI specification.
**/
int pci_msi_vec_count(struct pci_dev *dev)
{
int ret;
u16 msgctl;
if (!dev->msi_cap)
return -EINVAL;
pci_read_config_word(dev, dev->msi_cap + PCI_MSI_FLAGS, &msgctl);
ret = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
return ret;
}
EXPORT_SYMBOL(pci_msi_vec_count);
static void pci_msi_shutdown(struct pci_dev *dev)
{
struct msi_desc *desc;
if (!pci_msi_enable || !dev || !dev->msi_enabled)
return;
pci_msi_set_enable(dev, 0);
pci_intx_for_msi(dev, 1);
dev->msi_enabled = 0;
/* Return the device with MSI unmasked as initial states */
desc = msi_first_desc(&dev->dev, MSI_DESC_ALL);
if (!WARN_ON_ONCE(!desc))
pci_msi_unmask(desc, msi_multi_mask(desc));
/* Restore dev->irq to its default pin-assertion IRQ */
dev->irq = desc->pci.msi_attrib.default_irq;
pcibios_alloc_irq(dev);
}
void pci_disable_msi(struct pci_dev *dev)
{
if (!pci_msi_enable || !dev || !dev->msi_enabled)
return;
msi_lock_descs(&dev->dev);
pci_msi_shutdown(dev);
free_msi_irqs(dev);
msi_unlock_descs(&dev->dev);
}
EXPORT_SYMBOL(pci_disable_msi);
/**
* pci_msix_vec_count - return the number of device's MSI-X table entries
* @dev: pointer to the pci_dev data structure of MSI-X device function
* This function returns the number of device's MSI-X table entries and
* therefore the number of MSI-X vectors device is capable of sending.
* It returns a negative errno if the device is not capable of sending MSI-X
* interrupts.
**/
int pci_msix_vec_count(struct pci_dev *dev)
{
u16 control;
if (!dev->msix_cap)
return -EINVAL;
pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
return msix_table_size(control);
}
EXPORT_SYMBOL(pci_msix_vec_count);
static int __pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries,
int nvec, struct irq_affinity *affd, int flags)
{
int nr_entries;
int i, j;
if (!pci_msi_supported(dev, nvec) || dev->current_state != PCI_D0)
return -EINVAL;
nr_entries = pci_msix_vec_count(dev);
if (nr_entries < 0)
return nr_entries;
if (nvec > nr_entries && !(flags & PCI_IRQ_VIRTUAL))
return nr_entries;
if (entries) {
/* Check for any invalid entries */
for (i = 0; i < nvec; i++) {
if (entries[i].entry >= nr_entries)
return -EINVAL; /* invalid entry */
for (j = i + 1; j < nvec; j++) {
if (entries[i].entry == entries[j].entry)
return -EINVAL; /* duplicate entry */
}
}
}
/* Check whether driver already requested for MSI IRQ */
if (dev->msi_enabled) {
pci_info(dev, "can't enable MSI-X (MSI IRQ already assigned)\n");
return -EINVAL;
}
return msix_capability_init(dev, entries, nvec, affd);
}
static void pci_msix_shutdown(struct pci_dev *dev)
{
struct msi_desc *desc;
if (!pci_msi_enable || !dev || !dev->msix_enabled)
return;
if (pci_dev_is_disconnected(dev)) {
dev->msix_enabled = 0;
return;
}
/* Return the device with MSI-X masked as initial states */
msi_for_each_desc(desc, &dev->dev, MSI_DESC_ALL)
pci_msix_mask(desc);
pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
pci_intx_for_msi(dev, 1);
dev->msix_enabled = 0;
pcibios_alloc_irq(dev);
}
void pci_disable_msix(struct pci_dev *dev)
{
if (!pci_msi_enable || !dev || !dev->msix_enabled)
return;
msi_lock_descs(&dev->dev);
pci_msix_shutdown(dev);
free_msi_irqs(dev);
msi_unlock_descs(&dev->dev);
}
EXPORT_SYMBOL(pci_disable_msix);
static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
struct irq_affinity *affd)
{
int nvec;
int rc;
if (!pci_msi_supported(dev, minvec) || dev->current_state != PCI_D0)
return -EINVAL;
/* Check whether driver already requested MSI-X IRQs */
if (dev->msix_enabled) {
pci_info(dev, "can't enable MSI (MSI-X already enabled)\n");
return -EINVAL;
}
if (maxvec < minvec)
return -ERANGE;
if (WARN_ON_ONCE(dev->msi_enabled))
return -EINVAL;
nvec = pci_msi_vec_count(dev);
if (nvec < 0)
return nvec;
if (nvec < minvec)
return -ENOSPC;
if (nvec > maxvec)
nvec = maxvec;
rc = pci_setup_msi_context(dev);
if (rc)
return rc;
for (;;) {
if (affd) {
nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
if (nvec < minvec)
return -ENOSPC;
}
rc = msi_capability_init(dev, nvec, affd);
if (rc == 0)
return nvec;
if (rc < 0)
return rc;
if (rc < minvec)
return -ENOSPC;
nvec = rc;
}
}
/* deprecated, don't use */
int pci_enable_msi(struct pci_dev *dev)
{
int rc = __pci_enable_msi_range(dev, 1, 1, NULL);
if (rc < 0)
return rc;
return 0;
}
EXPORT_SYMBOL(pci_enable_msi);
static int __pci_enable_msix_range(struct pci_dev *dev,
struct msix_entry *entries, int minvec,
int maxvec, struct irq_affinity *affd,
int flags)
{
int rc, nvec = maxvec;
if (maxvec < minvec)
return -ERANGE;
if (WARN_ON_ONCE(dev->msix_enabled))
return -EINVAL;
rc = pci_setup_msi_context(dev);
if (rc)
return rc;
for (;;) {
if (affd) {
nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
if (nvec < minvec)
return -ENOSPC;
}
rc = __pci_enable_msix(dev, entries, nvec, affd, flags);
if (rc == 0)
return nvec;
if (rc < 0)
return rc;
if (rc < minvec)
return -ENOSPC;
nvec = rc;
}
}
/**
* pci_enable_msix_range - configure device's MSI-X capability structure
* @dev: pointer to the pci_dev data structure of MSI-X device function
* @entries: pointer to an array of MSI-X entries
* @minvec: minimum number of MSI-X IRQs requested
* @maxvec: maximum number of MSI-X IRQs requested
*
* Setup the MSI-X capability structure of device function with a maximum
* possible number of interrupts in the range between @minvec and @maxvec
* upon its software driver call to request for MSI-X mode enabled on its
* hardware device function. It returns a negative errno if an error occurs.
* If it succeeds, it returns the actual number of interrupts allocated and
* indicates the successful configuration of MSI-X capability structure
* with new allocated MSI-X interrupts.
**/
int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
int minvec, int maxvec)
{
return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL, 0);
}
EXPORT_SYMBOL(pci_enable_msix_range);
/**
* pci_alloc_irq_vectors_affinity - allocate multiple IRQs for a device
* @dev: PCI device to operate on
* @min_vecs: minimum number of vectors required (must be >= 1)
* @max_vecs: maximum (desired) number of vectors
* @flags: flags or quirks for the allocation
* @affd: optional description of the affinity requirements
*
* Allocate up to @max_vecs interrupt vectors for @dev, using MSI-X or MSI
* vectors if available, and fall back to a single legacy vector
* if neither is available. Return the number of vectors allocated,
* (which might be smaller than @max_vecs) if successful, or a negative
* error code on error. If less than @min_vecs interrupt vectors are
* available for @dev the function will fail with -ENOSPC.
*
* To get the Linux IRQ number used for a vector that can be passed to
* request_irq() use the pci_irq_vector() helper.
*/
int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
unsigned int max_vecs, unsigned int flags,
struct irq_affinity *affd)
{
struct irq_affinity msi_default_affd = {0};
int nvecs = -ENOSPC;
if (flags & PCI_IRQ_AFFINITY) {
if (!affd)
affd = &msi_default_affd;
} else {
if (WARN_ON(affd))
affd = NULL;
}
if (flags & PCI_IRQ_MSIX) {
nvecs = __pci_enable_msix_range(dev, NULL, min_vecs, max_vecs,
affd, flags);
if (nvecs > 0)
return nvecs;
}
if (flags & PCI_IRQ_MSI) {
nvecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, affd);
if (nvecs > 0)
return nvecs;
}
/* use legacy IRQ if allowed */
if (flags & PCI_IRQ_LEGACY) {
if (min_vecs == 1 && dev->irq) {
/*
* Invoke the affinity spreading logic to ensure that
* the device driver can adjust queue configuration
* for the single interrupt case.
*/
if (affd)
irq_create_affinity_masks(1, affd);
pci_intx(dev, 1);
return 1;
}
}
return nvecs;
}
EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity);
/**
* pci_free_irq_vectors - free previously allocated IRQs for a device
* @dev: PCI device to operate on
*
* Undoes the allocations and enabling in pci_alloc_irq_vectors().
*/
void pci_free_irq_vectors(struct pci_dev *dev)
{
pci_disable_msix(dev);
pci_disable_msi(dev);
}
EXPORT_SYMBOL(pci_free_irq_vectors);
/**
* pci_irq_vector - return Linux IRQ number of a device vector
* @dev: PCI device to operate on
* @nr: Interrupt vector index (0-based)
*
* @nr has the following meanings depending on the interrupt mode:
* MSI-X: The index in the MSI-X vector table
* MSI: The index of the enabled MSI vectors
* INTx: Must be 0
*
* Return: The Linux interrupt number or -EINVAl if @nr is out of range.
*/
int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
{
unsigned int irq;
if (!dev->msi_enabled && !dev->msix_enabled)
return !nr ? dev->irq : -EINVAL;
irq = msi_get_virq(&dev->dev, nr);
return irq ? irq : -EINVAL;
}
EXPORT_SYMBOL(pci_irq_vector);
/**
* pci_irq_get_affinity - return the affinity of a particular MSI vector
* @dev: PCI device to operate on
* @nr: device-relative interrupt vector index (0-based).
*
* @nr has the following meanings depending on the interrupt mode:
* MSI-X: The index in the MSI-X vector table
* MSI: The index of the enabled MSI vectors
* INTx: Must be 0
*
* Return: A cpumask pointer or NULL if @nr is out of range
*/
const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
{
int idx, irq = pci_irq_vector(dev, nr);
struct msi_desc *desc;
if (WARN_ON_ONCE(irq <= 0))
return NULL;
desc = irq_get_msi_desc(irq);
/* Non-MSI does not have the information handy */
if (!desc)
return cpu_possible_mask;
/* MSI[X] interrupts can be allocated without affinity descriptor */
if (!desc->affinity)
return NULL;
/*
* MSI has a mask array in the descriptor.
* MSI-X has a single mask.
*/
idx = dev->msi_enabled ? nr : 0;
return &desc->affinity[idx].mask;
}
EXPORT_SYMBOL(pci_irq_get_affinity);
struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc)
{
return to_pci_dev(desc->dev);
}
EXPORT_SYMBOL(msi_desc_to_pci_dev);
void pci_no_msi(void)
{
pci_msi_enable = 0;
}
/**
* pci_msi_enabled - is MSI enabled?
*
* Returns true if MSI has not been disabled by the command-line option
* pci=nomsi.
**/
int pci_msi_enabled(void)
{
return pci_msi_enable;
}
EXPORT_SYMBOL(pci_msi_enabled);
