linux/drivers/pci/msi.c
Jesse Barnes abad2ec98f PCI: fully restore MSI state at resume time
With the recent change to avoid masking MSIs using the MSI enable bit, devices
without an MSI mask bit will have their MSI capability always enabled when MSI
is in use, so we need to restore it regardless of the mask bit state.

Fixes kernel bz 11178.

Acked-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-08-07 08:52:37 -07:00

763 lines
19 KiB
C

/*
* File: msi.c
* Purpose: PCI Message Signaled Interrupt (MSI)
*
* Copyright (C) 2003-2004 Intel
* Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
*/
#include <linux/err.h>
#include <linux/mm.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/msi.h>
#include <linux/smp.h>
#include <asm/errno.h>
#include <asm/io.h>
#include "pci.h"
#include "msi.h"
static int pci_msi_enable = 1;
/* Arch hooks */
int __attribute__ ((weak))
arch_msi_check_device(struct pci_dev *dev, int nvec, int type)
{
return 0;
}
int __attribute__ ((weak))
arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *entry)
{
return 0;
}
int __attribute__ ((weak))
arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
{
struct msi_desc *entry;
int ret;
list_for_each_entry(entry, &dev->msi_list, list) {
ret = arch_setup_msi_irq(dev, entry);
if (ret)
return ret;
}
return 0;
}
void __attribute__ ((weak)) arch_teardown_msi_irq(unsigned int irq)
{
return;
}
void __attribute__ ((weak))
arch_teardown_msi_irqs(struct pci_dev *dev)
{
struct msi_desc *entry;
list_for_each_entry(entry, &dev->msi_list, list) {
if (entry->irq != 0)
arch_teardown_msi_irq(entry->irq);
}
}
static void __msi_set_enable(struct pci_dev *dev, int pos, int enable)
{
u16 control;
if (pos) {
pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
control &= ~PCI_MSI_FLAGS_ENABLE;
if (enable)
control |= PCI_MSI_FLAGS_ENABLE;
pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
}
}
static void msi_set_enable(struct pci_dev *dev, int enable)
{
__msi_set_enable(dev, pci_find_capability(dev, PCI_CAP_ID_MSI), enable);
}
static void msix_set_enable(struct pci_dev *dev, int enable)
{
int pos;
u16 control;
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (pos) {
pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
control &= ~PCI_MSIX_FLAGS_ENABLE;
if (enable)
control |= PCI_MSIX_FLAGS_ENABLE;
pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
}
}
static void msix_flush_writes(unsigned int irq)
{
struct msi_desc *entry;
entry = get_irq_msi(irq);
BUG_ON(!entry || !entry->dev);
switch (entry->msi_attrib.type) {
case PCI_CAP_ID_MSI:
/* nothing to do */
break;
case PCI_CAP_ID_MSIX:
{
int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET;
readl(entry->mask_base + offset);
break;
}
default:
BUG();
break;
}
}
/*
* PCI 2.3 does not specify mask bits for each MSI interrupt. Attempting to
* mask all MSI interrupts by clearing the MSI enable bit does not work
* reliably as devices without an INTx disable bit will then generate a
* level IRQ which will never be cleared.
*
* Returns 1 if it succeeded in masking the interrupt and 0 if the device
* doesn't support MSI masking.
*/
static int msi_set_mask_bits(unsigned int irq, u32 mask, u32 flag)
{
struct msi_desc *entry;
entry = get_irq_msi(irq);
BUG_ON(!entry || !entry->dev);
switch (entry->msi_attrib.type) {
case PCI_CAP_ID_MSI:
if (entry->msi_attrib.maskbit) {
int pos;
u32 mask_bits;
pos = (long)entry->mask_base;
pci_read_config_dword(entry->dev, pos, &mask_bits);
mask_bits &= ~(mask);
mask_bits |= flag & mask;
pci_write_config_dword(entry->dev, pos, mask_bits);
} else {
return 0;
}
break;
case PCI_CAP_ID_MSIX:
{
int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET;
writel(flag, entry->mask_base + offset);
readl(entry->mask_base + offset);
break;
}
default:
BUG();
break;
}
entry->msi_attrib.masked = !!flag;
return 1;
}
void read_msi_msg(unsigned int irq, struct msi_msg *msg)
{
struct msi_desc *entry = get_irq_msi(irq);
switch(entry->msi_attrib.type) {
case PCI_CAP_ID_MSI:
{
struct pci_dev *dev = entry->dev;
int pos = entry->msi_attrib.pos;
u16 data;
pci_read_config_dword(dev, msi_lower_address_reg(pos),
&msg->address_lo);
if (entry->msi_attrib.is_64) {
pci_read_config_dword(dev, msi_upper_address_reg(pos),
&msg->address_hi);
pci_read_config_word(dev, msi_data_reg(pos, 1), &data);
} else {
msg->address_hi = 0;
pci_read_config_word(dev, msi_data_reg(pos, 0), &data);
}
msg->data = data;
break;
}
case PCI_CAP_ID_MSIX:
{
void __iomem *base;
base = entry->mask_base +
entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
msg->data = readl(base + PCI_MSIX_ENTRY_DATA_OFFSET);
break;
}
default:
BUG();
}
}
void write_msi_msg(unsigned int irq, struct msi_msg *msg)
{
struct msi_desc *entry = get_irq_msi(irq);
switch (entry->msi_attrib.type) {
case PCI_CAP_ID_MSI:
{
struct pci_dev *dev = entry->dev;
int pos = entry->msi_attrib.pos;
pci_write_config_dword(dev, msi_lower_address_reg(pos),
msg->address_lo);
if (entry->msi_attrib.is_64) {
pci_write_config_dword(dev, msi_upper_address_reg(pos),
msg->address_hi);
pci_write_config_word(dev, msi_data_reg(pos, 1),
msg->data);
} else {
pci_write_config_word(dev, msi_data_reg(pos, 0),
msg->data);
}
break;
}
case PCI_CAP_ID_MSIX:
{
void __iomem *base;
base = entry->mask_base +
entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
writel(msg->address_lo,
base + PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
writel(msg->address_hi,
base + PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
writel(msg->data, base + PCI_MSIX_ENTRY_DATA_OFFSET);
break;
}
default:
BUG();
}
entry->msg = *msg;
}
void mask_msi_irq(unsigned int irq)
{
msi_set_mask_bits(irq, 1, 1);
msix_flush_writes(irq);
}
void unmask_msi_irq(unsigned int irq)
{
msi_set_mask_bits(irq, 1, 0);
msix_flush_writes(irq);
}
static int msi_free_irqs(struct pci_dev* dev);
static struct msi_desc* alloc_msi_entry(void)
{
struct msi_desc *entry;
entry = kzalloc(sizeof(struct msi_desc), GFP_KERNEL);
if (!entry)
return NULL;
INIT_LIST_HEAD(&entry->list);
entry->irq = 0;
entry->dev = NULL;
return entry;
}
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_restore_msi_state(struct pci_dev *dev)
{
int pos;
u16 control;
struct msi_desc *entry;
if (!dev->msi_enabled)
return;
entry = get_irq_msi(dev->irq);
pos = entry->msi_attrib.pos;
pci_intx_for_msi(dev, 0);
msi_set_enable(dev, 0);
write_msi_msg(dev->irq, &entry->msg);
if (entry->msi_attrib.maskbit)
msi_set_mask_bits(dev->irq, entry->msi_attrib.maskbits_mask,
entry->msi_attrib.masked);
pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
control &= ~PCI_MSI_FLAGS_QSIZE;
control |= PCI_MSI_FLAGS_ENABLE;
pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
}
static void __pci_restore_msix_state(struct pci_dev *dev)
{
int pos;
struct msi_desc *entry;
u16 control;
if (!dev->msix_enabled)
return;
/* route the table */
pci_intx_for_msi(dev, 0);
msix_set_enable(dev, 0);
list_for_each_entry(entry, &dev->msi_list, list) {
write_msi_msg(entry->irq, &entry->msg);
msi_set_mask_bits(entry->irq, 1, entry->msi_attrib.masked);
}
BUG_ON(list_empty(&dev->msi_list));
entry = list_entry(dev->msi_list.next, struct msi_desc, list);
pos = entry->msi_attrib.pos;
pci_read_config_word(dev, pos + PCI_MSIX_FLAGS, &control);
control &= ~PCI_MSIX_FLAGS_MASKALL;
control |= PCI_MSIX_FLAGS_ENABLE;
pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
}
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);
/**
* msi_capability_init - configure device's MSI capability structure
* @dev: pointer to the pci_dev data structure of MSI device function
*
* Setup the MSI capability structure of device function with a single
* MSI irq, regardless of device function is capable of handling
* multiple messages. A return of zero indicates the successful setup
* of an entry zero with the new MSI irq or non-zero for otherwise.
**/
static int msi_capability_init(struct pci_dev *dev)
{
struct msi_desc *entry;
int pos, ret;
u16 control;
msi_set_enable(dev, 0); /* Ensure msi is disabled as I set it up */
pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
pci_read_config_word(dev, msi_control_reg(pos), &control);
/* MSI Entry Initialization */
entry = alloc_msi_entry();
if (!entry)
return -ENOMEM;
entry->msi_attrib.type = PCI_CAP_ID_MSI;
entry->msi_attrib.is_64 = is_64bit_address(control);
entry->msi_attrib.entry_nr = 0;
entry->msi_attrib.maskbit = is_mask_bit_support(control);
entry->msi_attrib.masked = 1;
entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */
entry->msi_attrib.pos = pos;
if (is_mask_bit_support(control)) {
entry->mask_base = (void __iomem *)(long)msi_mask_bits_reg(pos,
is_64bit_address(control));
}
entry->dev = dev;
if (entry->msi_attrib.maskbit) {
unsigned int maskbits, temp;
/* All MSIs are unmasked by default, Mask them all */
pci_read_config_dword(dev,
msi_mask_bits_reg(pos, is_64bit_address(control)),
&maskbits);
temp = (1 << multi_msi_capable(control));
temp = ((temp - 1) & ~temp);
maskbits |= temp;
pci_write_config_dword(dev,
msi_mask_bits_reg(pos, is_64bit_address(control)),
maskbits);
entry->msi_attrib.maskbits_mask = temp;
}
list_add_tail(&entry->list, &dev->msi_list);
/* Configure MSI capability structure */
ret = arch_setup_msi_irqs(dev, 1, PCI_CAP_ID_MSI);
if (ret) {
msi_free_irqs(dev);
return ret;
}
/* Set MSI enabled bits */
pci_intx_for_msi(dev, 0);
msi_set_enable(dev, 1);
dev->msi_enabled = 1;
dev->irq = entry->irq;
return 0;
}
/**
* 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
*
* 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 msi_desc *entry;
int pos, i, j, nr_entries, ret;
unsigned long phys_addr;
u32 table_offset;
u16 control;
u8 bir;
void __iomem *base;
msix_set_enable(dev, 0);/* Ensure msix is disabled as I set it up */
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
/* Request & Map MSI-X table region */
pci_read_config_word(dev, msi_control_reg(pos), &control);
nr_entries = multi_msix_capable(control);
pci_read_config_dword(dev, msix_table_offset_reg(pos), &table_offset);
bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
table_offset &= ~PCI_MSIX_FLAGS_BIRMASK;
phys_addr = pci_resource_start (dev, bir) + table_offset;
base = ioremap_nocache(phys_addr, nr_entries * PCI_MSIX_ENTRY_SIZE);
if (base == NULL)
return -ENOMEM;
/* MSI-X Table Initialization */
for (i = 0; i < nvec; i++) {
entry = alloc_msi_entry();
if (!entry)
break;
j = entries[i].entry;
entry->msi_attrib.type = PCI_CAP_ID_MSIX;
entry->msi_attrib.is_64 = 1;
entry->msi_attrib.entry_nr = j;
entry->msi_attrib.maskbit = 1;
entry->msi_attrib.masked = 1;
entry->msi_attrib.default_irq = dev->irq;
entry->msi_attrib.pos = pos;
entry->dev = dev;
entry->mask_base = base;
list_add_tail(&entry->list, &dev->msi_list);
}
ret = arch_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX);
if (ret) {
int avail = 0;
list_for_each_entry(entry, &dev->msi_list, list) {
if (entry->irq != 0) {
avail++;
}
}
msi_free_irqs(dev);
/* If we had some success report the number of irqs
* we succeeded in setting up.
*/
if (avail == 0)
avail = ret;
return avail;
}
i = 0;
list_for_each_entry(entry, &dev->msi_list, list) {
entries[i].vector = entry->irq;
set_irq_msi(entry->irq, entry);
i++;
}
/* Set MSI-X enabled bits */
pci_intx_for_msi(dev, 0);
msix_set_enable(dev, 1);
dev->msix_enabled = 1;
return 0;
}
/**
* pci_msi_check_device - 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 ?
* @type: are we checking for MSI or MSI-X ?
*
* Look at global flags, the device itself, and its parent busses
* to determine if MSI/-X are supported for the device. If MSI/-X is
* supported return 0, else return an error code.
**/
static int pci_msi_check_device(struct pci_dev* dev, int nvec, int type)
{
struct pci_bus *bus;
int ret;
/* MSI must be globally enabled and supported by the device */
if (!pci_msi_enable || !dev || dev->no_msi)
return -EINVAL;
/*
* 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 -ERANGE;
/* Any bridge which does NOT route MSI transactions from it's
* secondary bus to it's primary bus must set NO_MSI flag on
* the secondary pci_bus.
* We expect only arch-specific PCI host bus controller driver
* or quirks for specific PCI bridges to be setting NO_MSI.
*/
for (bus = dev->bus; bus; bus = bus->parent)
if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
return -EINVAL;
ret = arch_msi_check_device(dev, nvec, type);
if (ret)
return ret;
if (!pci_find_capability(dev, type))
return -EINVAL;
return 0;
}
/**
* pci_enable_msi - configure device's MSI capability structure
* @dev: pointer to the pci_dev data structure of MSI device function
*
* Setup the MSI capability structure of device function with
* a single MSI irq upon its software driver call to request for
* MSI mode enabled on its hardware device function. A return of zero
* indicates the successful setup of an entry zero with the new MSI
* irq or non-zero for otherwise.
**/
int pci_enable_msi(struct pci_dev* dev)
{
int status;
status = pci_msi_check_device(dev, 1, PCI_CAP_ID_MSI);
if (status)
return status;
WARN_ON(!!dev->msi_enabled);
/* Check whether driver already requested for MSI-X irqs */
if (dev->msix_enabled) {
dev_info(&dev->dev, "can't enable MSI "
"(MSI-X already enabled)\n");
return -EINVAL;
}
status = msi_capability_init(dev);
return status;
}
EXPORT_SYMBOL(pci_enable_msi);
void pci_msi_shutdown(struct pci_dev* dev)
{
struct msi_desc *entry;
if (!pci_msi_enable || !dev || !dev->msi_enabled)
return;
msi_set_enable(dev, 0);
pci_intx_for_msi(dev, 1);
dev->msi_enabled = 0;
BUG_ON(list_empty(&dev->msi_list));
entry = list_entry(dev->msi_list.next, struct msi_desc, list);
/* Return the the pci reset with msi irqs unmasked */
if (entry->msi_attrib.maskbit) {
u32 mask = entry->msi_attrib.maskbits_mask;
msi_set_mask_bits(dev->irq, mask, ~mask);
}
if (!entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI)
return;
/* Restore dev->irq to its default pin-assertion irq */
dev->irq = entry->msi_attrib.default_irq;
}
void pci_disable_msi(struct pci_dev* dev)
{
struct msi_desc *entry;
if (!pci_msi_enable || !dev || !dev->msi_enabled)
return;
pci_msi_shutdown(dev);
entry = list_entry(dev->msi_list.next, struct msi_desc, list);
if (!entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI)
return;
msi_free_irqs(dev);
}
EXPORT_SYMBOL(pci_disable_msi);
static int msi_free_irqs(struct pci_dev* dev)
{
struct msi_desc *entry, *tmp;
list_for_each_entry(entry, &dev->msi_list, list) {
if (entry->irq)
BUG_ON(irq_has_action(entry->irq));
}
arch_teardown_msi_irqs(dev);
list_for_each_entry_safe(entry, tmp, &dev->msi_list, list) {
if (entry->msi_attrib.type == PCI_CAP_ID_MSIX) {
writel(1, entry->mask_base + entry->msi_attrib.entry_nr
* PCI_MSIX_ENTRY_SIZE
+ PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
if (list_is_last(&entry->list, &dev->msi_list))
iounmap(entry->mask_base);
}
list_del(&entry->list);
kfree(entry);
}
return 0;
}
/**
* pci_enable_msix - 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
* @nvec: number of MSI-X irqs requested for allocation by device driver
*
* Setup the MSI-X capability structure of device function with the number
* of requested irqs upon its software driver call to request for
* MSI-X mode enabled on its hardware device function. A return of zero
* indicates the successful configuration of MSI-X capability structure
* with new allocated MSI-X irqs. A return of < 0 indicates a failure.
* Or a return of > 0 indicates that driver request is exceeding the number
* of irqs available. Driver should use the returned value to re-send
* its request.
**/
int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
{
int status, pos, nr_entries;
int i, j;
u16 control;
if (!entries)
return -EINVAL;
status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSIX);
if (status)
return status;
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
pci_read_config_word(dev, msi_control_reg(pos), &control);
nr_entries = multi_msix_capable(control);
if (nvec > nr_entries)
return -EINVAL;
/* 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 */
}
}
WARN_ON(!!dev->msix_enabled);
/* Check whether driver already requested for MSI irq */
if (dev->msi_enabled) {
dev_info(&dev->dev, "can't enable MSI-X "
"(MSI IRQ already assigned)\n");
return -EINVAL;
}
status = msix_capability_init(dev, entries, nvec);
return status;
}
EXPORT_SYMBOL(pci_enable_msix);
static void msix_free_all_irqs(struct pci_dev *dev)
{
msi_free_irqs(dev);
}
void pci_msix_shutdown(struct pci_dev* dev)
{
if (!pci_msi_enable || !dev || !dev->msix_enabled)
return;
msix_set_enable(dev, 0);
pci_intx_for_msi(dev, 1);
dev->msix_enabled = 0;
}
void pci_disable_msix(struct pci_dev* dev)
{
if (!pci_msi_enable || !dev || !dev->msix_enabled)
return;
pci_msix_shutdown(dev);
msix_free_all_irqs(dev);
}
EXPORT_SYMBOL(pci_disable_msix);
/**
* msi_remove_pci_irq_vectors - reclaim MSI(X) irqs to unused state
* @dev: pointer to the pci_dev data structure of MSI(X) device function
*
* Being called during hotplug remove, from which the device function
* is hot-removed. All previous assigned MSI/MSI-X irqs, if
* allocated for this device function, are reclaimed to unused state,
* which may be used later on.
**/
void msi_remove_pci_irq_vectors(struct pci_dev* dev)
{
if (!pci_msi_enable || !dev)
return;
if (dev->msi_enabled)
msi_free_irqs(dev);
if (dev->msix_enabled)
msix_free_all_irqs(dev);
}
void pci_no_msi(void)
{
pci_msi_enable = 0;
}
void pci_msi_init_pci_dev(struct pci_dev *dev)
{
INIT_LIST_HEAD(&dev->msi_list);
}