linux/drivers/pci/msi.c

1041 lines
26 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/smp_lock.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <asm/errno.h>
#include <asm/io.h>
#include <asm/smp.h>
#include "pci.h"
#include "msi.h"
static DEFINE_SPINLOCK(msi_lock);
static struct msi_desc* msi_desc[NR_IRQS] = { [0 ... NR_IRQS-1] = NULL };
static kmem_cache_t* msi_cachep;
static int pci_msi_enable = 1;
static struct msi_ops *msi_ops;
int
msi_register(struct msi_ops *ops)
{
msi_ops = ops;
return 0;
}
static int msi_cache_init(void)
{
msi_cachep = kmem_cache_create("msi_cache", sizeof(struct msi_desc),
0, SLAB_HWCACHE_ALIGN, NULL, NULL);
if (!msi_cachep)
return -ENOMEM;
return 0;
}
static void msi_set_mask_bit(unsigned int irq, int flag)
{
struct msi_desc *entry;
entry = msi_desc[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 &= ~(1);
mask_bits |= flag;
pci_write_config_dword(entry->dev, pos, mask_bits);
}
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);
break;
}
default:
BUG();
break;
}
}
static void read_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
{
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, 1), &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();
}
}
static void write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
{
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();
}
}
#ifdef CONFIG_SMP
static void set_msi_affinity(unsigned int irq, cpumask_t cpu_mask)
{
struct msi_desc *entry;
struct msi_msg msg;
entry = msi_desc[irq];
if (!entry || !entry->dev)
return;
read_msi_msg(entry, &msg);
msi_ops->target(irq, cpu_mask, &msg);
write_msi_msg(entry, &msg);
set_native_irq_info(irq, cpu_mask);
}
#else
#define set_msi_affinity NULL
#endif /* CONFIG_SMP */
static void mask_MSI_irq(unsigned int irq)
{
msi_set_mask_bit(irq, 1);
}
static void unmask_MSI_irq(unsigned int irq)
{
msi_set_mask_bit(irq, 0);
}
static void ack_msi_irq(unsigned int irq)
{
move_native_irq(irq);
ack_APIC_irq();
}
/*
* IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices,
* which implement the MSI or MSI-X Capability Structure.
*/
static struct irq_chip msi_chip = {
.name = "PCI-MSI",
.unmask = unmask_MSI_irq,
.mask = mask_MSI_irq,
.ack = ack_msi_irq,
.set_affinity = set_msi_affinity
};
static int msi_free_irq(struct pci_dev* dev, int irq);
static int msi_init(void)
{
static int status = -ENOMEM;
if (!status)
return status;
if (pci_msi_quirk) {
pci_msi_enable = 0;
printk(KERN_WARNING "PCI: MSI quirk detected. MSI disabled.\n");
status = -EINVAL;
return status;
}
status = msi_arch_init();
if (status < 0) {
pci_msi_enable = 0;
printk(KERN_WARNING
"PCI: MSI arch init failed. MSI disabled.\n");
return status;
}
if (! msi_ops) {
pci_msi_enable = 0;
printk(KERN_WARNING
"PCI: MSI ops not registered. MSI disabled.\n");
status = -EINVAL;
return status;
}
status = msi_cache_init();
if (status < 0) {
pci_msi_enable = 0;
printk(KERN_WARNING "PCI: MSI cache init failed\n");
return status;
}
return status;
}
static struct msi_desc* alloc_msi_entry(void)
{
struct msi_desc *entry;
entry = kmem_cache_zalloc(msi_cachep, GFP_KERNEL);
if (!entry)
return NULL;
entry->link.tail = entry->link.head = 0; /* single message */
entry->dev = NULL;
return entry;
}
static void attach_msi_entry(struct msi_desc *entry, int irq)
{
unsigned long flags;
spin_lock_irqsave(&msi_lock, flags);
msi_desc[irq] = entry;
spin_unlock_irqrestore(&msi_lock, flags);
}
static int create_msi_irq(struct irq_chip *chip)
{
struct msi_desc *entry;
int irq;
entry = alloc_msi_entry();
if (!entry)
return -ENOMEM;
irq = create_irq();
if (irq < 0) {
kmem_cache_free(msi_cachep, entry);
return -EBUSY;
}
set_irq_chip_and_handler(irq, chip, handle_edge_irq);
set_irq_data(irq, entry);
return irq;
}
static void destroy_msi_irq(unsigned int irq)
{
struct msi_desc *entry;
entry = get_irq_data(irq);
set_irq_chip(irq, NULL);
set_irq_data(irq, NULL);
destroy_irq(irq);
kmem_cache_free(msi_cachep, entry);
}
static void enable_msi_mode(struct pci_dev *dev, int pos, int type)
{
u16 control;
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (type == PCI_CAP_ID_MSI) {
/* Set enabled bits to single MSI & enable MSI_enable bit */
msi_enable(control, 1);
pci_write_config_word(dev, msi_control_reg(pos), control);
dev->msi_enabled = 1;
} else {
msix_enable(control);
pci_write_config_word(dev, msi_control_reg(pos), control);
dev->msix_enabled = 1;
}
if (pci_find_capability(dev, PCI_CAP_ID_EXP)) {
/* PCI Express Endpoint device detected */
pci_intx(dev, 0); /* disable intx */
}
}
void disable_msi_mode(struct pci_dev *dev, int pos, int type)
{
u16 control;
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (type == PCI_CAP_ID_MSI) {
/* Set enabled bits to single MSI & enable MSI_enable bit */
msi_disable(control);
pci_write_config_word(dev, msi_control_reg(pos), control);
dev->msi_enabled = 0;
} else {
msix_disable(control);
pci_write_config_word(dev, msi_control_reg(pos), control);
dev->msix_enabled = 0;
}
if (pci_find_capability(dev, PCI_CAP_ID_EXP)) {
/* PCI Express Endpoint device detected */
pci_intx(dev, 1); /* enable intx */
}
}
static int msi_lookup_irq(struct pci_dev *dev, int type)
{
int irq;
unsigned long flags;
spin_lock_irqsave(&msi_lock, flags);
for (irq = 0; irq < NR_IRQS; irq++) {
if (!msi_desc[irq] || msi_desc[irq]->dev != dev ||
msi_desc[irq]->msi_attrib.type != type ||
msi_desc[irq]->msi_attrib.default_irq != dev->irq)
continue;
spin_unlock_irqrestore(&msi_lock, flags);
/* This pre-assigned MSI irq for this device
already exits. Override dev->irq with this irq */
dev->irq = irq;
return 0;
}
spin_unlock_irqrestore(&msi_lock, flags);
return -EACCES;
}
void pci_scan_msi_device(struct pci_dev *dev)
{
if (!dev)
return;
}
#ifdef CONFIG_PM
int pci_save_msi_state(struct pci_dev *dev)
{
int pos, i = 0;
u16 control;
struct pci_cap_saved_state *save_state;
u32 *cap;
pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
if (pos <= 0 || dev->no_msi)
return 0;
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (!(control & PCI_MSI_FLAGS_ENABLE))
return 0;
save_state = kzalloc(sizeof(struct pci_cap_saved_state) + sizeof(u32) * 5,
GFP_KERNEL);
if (!save_state) {
printk(KERN_ERR "Out of memory in pci_save_msi_state\n");
return -ENOMEM;
}
cap = &save_state->data[0];
pci_read_config_dword(dev, pos, &cap[i++]);
control = cap[0] >> 16;
pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_LO, &cap[i++]);
if (control & PCI_MSI_FLAGS_64BIT) {
pci_read_config_dword(dev, pos + PCI_MSI_ADDRESS_HI, &cap[i++]);
pci_read_config_dword(dev, pos + PCI_MSI_DATA_64, &cap[i++]);
} else
pci_read_config_dword(dev, pos + PCI_MSI_DATA_32, &cap[i++]);
if (control & PCI_MSI_FLAGS_MASKBIT)
pci_read_config_dword(dev, pos + PCI_MSI_MASK_BIT, &cap[i++]);
save_state->cap_nr = PCI_CAP_ID_MSI;
pci_add_saved_cap(dev, save_state);
return 0;
}
void pci_restore_msi_state(struct pci_dev *dev)
{
int i = 0, pos;
u16 control;
struct pci_cap_saved_state *save_state;
u32 *cap;
save_state = pci_find_saved_cap(dev, PCI_CAP_ID_MSI);
pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
if (!save_state || pos <= 0)
return;
cap = &save_state->data[0];
control = cap[i++] >> 16;
pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_LO, cap[i++]);
if (control & PCI_MSI_FLAGS_64BIT) {
pci_write_config_dword(dev, pos + PCI_MSI_ADDRESS_HI, cap[i++]);
pci_write_config_dword(dev, pos + PCI_MSI_DATA_64, cap[i++]);
} else
pci_write_config_dword(dev, pos + PCI_MSI_DATA_32, cap[i++]);
if (control & PCI_MSI_FLAGS_MASKBIT)
pci_write_config_dword(dev, pos + PCI_MSI_MASK_BIT, cap[i++]);
pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
pci_remove_saved_cap(save_state);
kfree(save_state);
}
int pci_save_msix_state(struct pci_dev *dev)
{
int pos;
int temp;
int irq, head, tail = 0;
u16 control;
struct pci_cap_saved_state *save_state;
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (pos <= 0 || dev->no_msi)
return 0;
/* save the capability */
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (!(control & PCI_MSIX_FLAGS_ENABLE))
return 0;
save_state = kzalloc(sizeof(struct pci_cap_saved_state) + sizeof(u16),
GFP_KERNEL);
if (!save_state) {
printk(KERN_ERR "Out of memory in pci_save_msix_state\n");
return -ENOMEM;
}
*((u16 *)&save_state->data[0]) = control;
/* save the table */
temp = dev->irq;
if (msi_lookup_irq(dev, PCI_CAP_ID_MSIX)) {
kfree(save_state);
return -EINVAL;
}
irq = head = dev->irq;
while (head != tail) {
struct msi_desc *entry;
entry = msi_desc[irq];
read_msi_msg(entry, &entry->msg_save);
tail = msi_desc[irq]->link.tail;
irq = tail;
}
dev->irq = temp;
save_state->cap_nr = PCI_CAP_ID_MSIX;
pci_add_saved_cap(dev, save_state);
return 0;
}
void pci_restore_msix_state(struct pci_dev *dev)
{
u16 save;
int pos;
int irq, head, tail = 0;
struct msi_desc *entry;
int temp;
struct pci_cap_saved_state *save_state;
save_state = pci_find_saved_cap(dev, PCI_CAP_ID_MSIX);
if (!save_state)
return;
save = *((u16 *)&save_state->data[0]);
pci_remove_saved_cap(save_state);
kfree(save_state);
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (pos <= 0)
return;
/* route the table */
temp = dev->irq;
if (msi_lookup_irq(dev, PCI_CAP_ID_MSIX))
return;
irq = head = dev->irq;
while (head != tail) {
entry = msi_desc[irq];
write_msi_msg(entry, &entry->msg_save);
tail = msi_desc[irq]->link.tail;
irq = tail;
}
dev->irq = temp;
pci_write_config_word(dev, msi_control_reg(pos), save);
enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
}
#endif
static int msi_register_init(struct pci_dev *dev, struct msi_desc *entry)
{
int status;
struct msi_msg msg;
int pos;
u16 control;
pos = entry->msi_attrib.pos;
pci_read_config_word(dev, msi_control_reg(pos), &control);
/* Configure MSI capability structure */
status = msi_ops->setup(dev, dev->irq, &msg);
if (status < 0)
return status;
write_msi_msg(entry, &msg);
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);
}
return 0;
}
/**
* 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)
{
int status;
struct msi_desc *entry;
int pos, irq;
u16 control;
pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
pci_read_config_word(dev, msi_control_reg(pos), &control);
/* MSI Entry Initialization */
irq = create_msi_irq(&msi_chip);
if (irq < 0)
return irq;
entry = get_irq_data(irq);
entry->link.head = irq;
entry->link.tail = irq;
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.default_irq = dev->irq; /* Save IOAPIC IRQ */
entry->msi_attrib.pos = pos;
dev->irq = irq;
entry->dev = dev;
if (is_mask_bit_support(control)) {
entry->mask_base = (void __iomem *)(long)msi_mask_bits_reg(pos,
is_64bit_address(control));
}
/* Configure MSI capability structure */
status = msi_register_init(dev, entry);
if (status != 0) {
dev->irq = entry->msi_attrib.default_irq;
destroy_msi_irq(irq);
return status;
}
attach_msi_entry(entry, irq);
/* Set MSI enabled bits */
enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
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 *head = NULL, *tail = NULL, *entry = NULL;
struct msi_msg msg;
int status;
int irq, pos, i, j, nr_entries, temp = 0;
unsigned long phys_addr;
u32 table_offset;
u16 control;
u8 bir;
void __iomem *base;
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++) {
irq = create_msi_irq(&msi_chip);
if (irq < 0)
break;
entry = get_irq_data(irq);
j = entries[i].entry;
entries[i].vector = irq;
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.default_irq = dev->irq;
entry->msi_attrib.pos = pos;
entry->dev = dev;
entry->mask_base = base;
if (!head) {
entry->link.head = irq;
entry->link.tail = irq;
head = entry;
} else {
entry->link.head = temp;
entry->link.tail = tail->link.tail;
tail->link.tail = irq;
head->link.head = irq;
}
temp = irq;
tail = entry;
/* Configure MSI-X capability structure */
status = msi_ops->setup(dev, irq, &msg);
if (status < 0) {
destroy_msi_irq(irq);
break;
}
write_msi_msg(entry, &msg);
attach_msi_entry(entry, irq);
}
if (i != nvec) {
int avail = i - 1;
i--;
for (; i >= 0; i--) {
irq = (entries + i)->vector;
msi_free_irq(dev, irq);
(entries + i)->vector = 0;
}
/* If we had some success report the number of irqs
* we succeeded in setting up.
*/
if (avail <= 0)
avail = -EBUSY;
return avail;
}
/* Set MSI-X enabled bits */
enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
return 0;
}
/**
* pci_msi_supported - check whether MSI may be enabled on device
* @dev: pointer to the pci_dev data structure of MSI device function
*
* MSI must be globally enabled and supported by the device and its root
* bus. But, the root bus is not easy to find since some architectures
* have virtual busses on top of the PCI hierarchy (for instance the
* hypertransport bus), while the actual bus where MSI must be supported
* is below. So we test the MSI flag on all parent busses and assume
* that no quirk will ever set the NO_MSI flag on a non-root bus.
**/
static
int pci_msi_supported(struct pci_dev * dev)
{
struct pci_bus *bus;
if (!pci_msi_enable || !dev || dev->no_msi)
return -EINVAL;
/* check MSI flags of all parent busses */
for (bus = dev->bus; bus; bus = bus->parent)
if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
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 pos, temp, status;
u16 control;
if (pci_msi_supported(dev) < 0)
return -EINVAL;
temp = dev->irq;
status = msi_init();
if (status < 0)
return status;
pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
if (!pos)
return -EINVAL;
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (!is_64bit_address(control) && msi_ops->needs_64bit_address)
return -EINVAL;
WARN_ON(!msi_lookup_irq(dev, PCI_CAP_ID_MSI));
/* Check whether driver already requested for MSI-X irqs */
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (pos > 0 && !msi_lookup_irq(dev, PCI_CAP_ID_MSIX)) {
printk(KERN_INFO "PCI: %s: Can't enable MSI. "
"Device already has MSI-X irq assigned\n",
pci_name(dev));
dev->irq = temp;
return -EINVAL;
}
status = msi_capability_init(dev);
return status;
}
void pci_disable_msi(struct pci_dev* dev)
{
struct msi_desc *entry;
int pos, default_irq;
u16 control;
unsigned long flags;
if (!pci_msi_enable)
return;
if (!dev)
return;
pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
if (!pos)
return;
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (!(control & PCI_MSI_FLAGS_ENABLE))
return;
disable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
spin_lock_irqsave(&msi_lock, flags);
entry = msi_desc[dev->irq];
if (!entry || !entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) {
spin_unlock_irqrestore(&msi_lock, flags);
return;
}
if (irq_has_action(dev->irq)) {
spin_unlock_irqrestore(&msi_lock, flags);
printk(KERN_WARNING "PCI: %s: pci_disable_msi() called without "
"free_irq() on MSI irq %d\n",
pci_name(dev), dev->irq);
BUG_ON(irq_has_action(dev->irq));
} else {
default_irq = entry->msi_attrib.default_irq;
spin_unlock_irqrestore(&msi_lock, flags);
msi_free_irq(dev, dev->irq);
/* Restore dev->irq to its default pin-assertion irq */
dev->irq = default_irq;
}
}
static int msi_free_irq(struct pci_dev* dev, int irq)
{
struct msi_desc *entry;
int head, entry_nr, type;
void __iomem *base;
unsigned long flags;
msi_ops->teardown(irq);
spin_lock_irqsave(&msi_lock, flags);
entry = msi_desc[irq];
if (!entry || entry->dev != dev) {
spin_unlock_irqrestore(&msi_lock, flags);
return -EINVAL;
}
type = entry->msi_attrib.type;
entry_nr = entry->msi_attrib.entry_nr;
head = entry->link.head;
base = entry->mask_base;
msi_desc[entry->link.head]->link.tail = entry->link.tail;
msi_desc[entry->link.tail]->link.head = entry->link.head;
entry->dev = NULL;
msi_desc[irq] = NULL;
spin_unlock_irqrestore(&msi_lock, flags);
destroy_msi_irq(irq);
if (type == PCI_CAP_ID_MSIX) {
writel(1, base + entry_nr * PCI_MSIX_ENTRY_SIZE +
PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET);
if (head == irq)
iounmap(base);
}
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, temp;
u16 control;
if (!entries || pci_msi_supported(dev) < 0)
return -EINVAL;
status = msi_init();
if (status < 0)
return status;
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (!pos)
return -EINVAL;
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 */
}
}
temp = dev->irq;
WARN_ON(!msi_lookup_irq(dev, PCI_CAP_ID_MSIX));
/* Check whether driver already requested for MSI irq */
if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0 &&
!msi_lookup_irq(dev, PCI_CAP_ID_MSI)) {
printk(KERN_INFO "PCI: %s: Can't enable MSI-X. "
"Device already has an MSI irq assigned\n",
pci_name(dev));
dev->irq = temp;
return -EINVAL;
}
status = msix_capability_init(dev, entries, nvec);
return status;
}
void pci_disable_msix(struct pci_dev* dev)
{
int pos, temp;
u16 control;
if (!pci_msi_enable)
return;
if (!dev)
return;
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (!pos)
return;
pci_read_config_word(dev, msi_control_reg(pos), &control);
if (!(control & PCI_MSIX_FLAGS_ENABLE))
return;
disable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
temp = dev->irq;
if (!msi_lookup_irq(dev, PCI_CAP_ID_MSIX)) {
int irq, head, tail = 0, warning = 0;
unsigned long flags;
irq = head = dev->irq;
dev->irq = temp; /* Restore pin IRQ */
while (head != tail) {
spin_lock_irqsave(&msi_lock, flags);
tail = msi_desc[irq]->link.tail;
spin_unlock_irqrestore(&msi_lock, flags);
if (irq_has_action(irq))
warning = 1;
else if (irq != head) /* Release MSI-X irq */
msi_free_irq(dev, irq);
irq = tail;
}
msi_free_irq(dev, irq);
if (warning) {
printk(KERN_WARNING "PCI: %s: pci_disable_msix() called without "
"free_irq() on all MSI-X irqs\n",
pci_name(dev));
BUG_ON(warning > 0);
}
}
}
/**
* 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)
{
int pos, temp;
unsigned long flags;
if (!pci_msi_enable || !dev)
return;
temp = dev->irq; /* Save IOAPIC IRQ */
pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
if (pos > 0 && !msi_lookup_irq(dev, PCI_CAP_ID_MSI)) {
if (irq_has_action(dev->irq)) {
printk(KERN_WARNING "PCI: %s: msi_remove_pci_irq_vectors() "
"called without free_irq() on MSI irq %d\n",
pci_name(dev), dev->irq);
BUG_ON(irq_has_action(dev->irq));
} else /* Release MSI irq assigned to this device */
msi_free_irq(dev, dev->irq);
dev->irq = temp; /* Restore IOAPIC IRQ */
}
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (pos > 0 && !msi_lookup_irq(dev, PCI_CAP_ID_MSIX)) {
int irq, head, tail = 0, warning = 0;
void __iomem *base = NULL;
irq = head = dev->irq;
while (head != tail) {
spin_lock_irqsave(&msi_lock, flags);
tail = msi_desc[irq]->link.tail;
base = msi_desc[irq]->mask_base;
spin_unlock_irqrestore(&msi_lock, flags);
if (irq_has_action(irq))
warning = 1;
else if (irq != head) /* Release MSI-X irq */
msi_free_irq(dev, irq);
irq = tail;
}
msi_free_irq(dev, irq);
if (warning) {
iounmap(base);
printk(KERN_WARNING "PCI: %s: msi_remove_pci_irq_vectors() "
"called without free_irq() on all MSI-X irqs\n",
pci_name(dev));
BUG_ON(warning > 0);
}
dev->irq = temp; /* Restore IOAPIC IRQ */
}
}
void pci_no_msi(void)
{
pci_msi_enable = 0;
}
EXPORT_SYMBOL(pci_enable_msi);
EXPORT_SYMBOL(pci_disable_msi);
EXPORT_SYMBOL(pci_enable_msix);
EXPORT_SYMBOL(pci_disable_msix);