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msi: Kill msi_lookup_irq
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The function msi_lookup_irq was horrible.  As a side effect of running
it changed dev->irq, and then the callers would need to change it
back.  In addition it does a global scan through all of the irqs,
which seems to be the sole justification of the msi_lock.

To remove the neede for msi_lookup_irq I added first_msi_irq to struct
pci_dev.  Then depending on the context I replaced msi_lookup_irq with
dev->first_msi_irq, dev->msi_enabled, or dev->msix_enabled.

msi_enabled and msix_enabled were already present in pci_dev for other
reasons.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Eric W. Biederman authored and Greg Kroah-Hartman committed Feb 7, 2007
1 parent 8fed4b6 commit ded86d8
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Showing 2 changed files with 62 additions and 90 deletions.
149 changes: 59 additions & 90 deletions drivers/pci/msi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -272,28 +272,6 @@ void disable_msi_mode(struct pci_dev *dev, int pos, int type)
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 exists. Override dev->irq with this irq */
dev->irq = irq;
return 0;
}
spin_unlock_irqrestore(&msi_lock, flags);

return -EACCES;
}

#ifdef CONFIG_PM
static int __pci_save_msi_state(struct pci_dev *dev)
{
Expand Down Expand Up @@ -364,11 +342,13 @@ static void __pci_restore_msi_state(struct pci_dev *dev)
static 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;

if (!dev->msix_enabled)
return 0;

pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (pos <= 0 || dev->no_msi)
return 0;
Expand All @@ -386,13 +366,7 @@ static int __pci_save_msix_state(struct pci_dev *dev)
*((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;
irq = head = dev->first_msi_irq;
while (head != tail) {
struct msi_desc *entry;

Expand All @@ -402,7 +376,6 @@ static int __pci_save_msix_state(struct pci_dev *dev)
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);
Expand All @@ -428,9 +401,11 @@ static void __pci_restore_msix_state(struct pci_dev *dev)
int pos;
int irq, head, tail = 0;
struct msi_desc *entry;
int temp;
struct pci_cap_saved_state *save_state;

if (!dev->msix_enabled)
return;

save_state = pci_find_saved_cap(dev, PCI_CAP_ID_MSIX);
if (!save_state)
return;
Expand All @@ -443,18 +418,14 @@ static void __pci_restore_msix_state(struct pci_dev *dev)
return;

/* route the table */
temp = dev->irq;
if (msi_lookup_irq(dev, PCI_CAP_ID_MSIX))
return;
irq = head = dev->irq;
irq = head = dev->first_msi_irq;
while (head != tail) {
entry = msi_desc[irq];
write_msi_msg(irq, &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);
Expand Down Expand Up @@ -524,6 +495,7 @@ static int msi_capability_init(struct pci_dev *dev)
return status;
}

dev->first_msi_irq = irq;
attach_msi_entry(entry, irq);
/* Set MSI enabled bits */
enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
Expand Down Expand Up @@ -620,6 +592,7 @@ static int msix_capability_init(struct pci_dev *dev,
avail = -EBUSY;
return avail;
}
dev->first_msi_irq = entries[0].vector;
/* Set MSI-X enabled bits */
enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);

Expand Down Expand Up @@ -667,13 +640,11 @@ int pci_msi_supported(struct pci_dev * dev)
**/
int pci_enable_msi(struct pci_dev* dev)
{
int pos, temp, status;
int pos, status;

if (pci_msi_supported(dev) < 0)
return -EINVAL;

temp = dev->irq;

status = msi_init();
if (status < 0)
return status;
Expand All @@ -682,15 +653,14 @@ int pci_enable_msi(struct pci_dev* dev)
if (!pos)
return -EINVAL;

WARN_ON(!msi_lookup_irq(dev, PCI_CAP_ID_MSI));
WARN_ON(!!dev->msi_enabled);

/* 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)) {
if (pos > 0 && dev->msix_enabled) {
printk(KERN_INFO "PCI: %s: Can't enable MSI. "
"Device already has MSI-X irq assigned\n",
"Device already has MSI-X enabled\n",
pci_name(dev));
dev->irq = temp;
return -EINVAL;
}
status = msi_capability_init(dev);
Expand All @@ -709,6 +679,9 @@ void pci_disable_msi(struct pci_dev* dev)
if (!dev)
return;

if (!dev->msi_enabled)
return;

pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
if (!pos)
return;
Expand All @@ -717,28 +690,30 @@ void pci_disable_msi(struct pci_dev* dev)
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];
entry = msi_desc[dev->first_msi_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)) {
if (irq_has_action(dev->first_msi_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));
pci_name(dev), dev->first_msi_irq);
BUG_ON(irq_has_action(dev->first_msi_irq));
} else {
default_irq = entry->msi_attrib.default_irq;
spin_unlock_irqrestore(&msi_lock, flags);
msi_free_irq(dev, dev->irq);
msi_free_irq(dev, dev->first_msi_irq);

/* Restore dev->irq to its default pin-assertion irq */
dev->irq = default_irq;
}
dev->first_msi_irq = 0;
}

static int msi_free_irq(struct pci_dev* dev, int irq)
Expand Down Expand Up @@ -797,7 +772,7 @@ static int msi_free_irq(struct pci_dev* dev, int irq)
int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
{
int status, pos, nr_entries;
int i, j, temp;
int i, j;
u16 control;

if (!entries || pci_msi_supported(dev) < 0)
Expand Down Expand Up @@ -825,16 +800,14 @@ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
return -EINVAL; /* duplicate entry */
}
}
temp = dev->irq;
WARN_ON(!msi_lookup_irq(dev, PCI_CAP_ID_MSIX));
WARN_ON(!!dev->msix_enabled);

/* 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)) {
dev->msi_enabled) {
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);
Expand All @@ -843,14 +816,19 @@ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)

void pci_disable_msix(struct pci_dev* dev)
{
int pos, temp;
int irq, head, tail = 0, warning = 0;
unsigned long flags;
int pos;
u16 control;

if (!pci_msi_enable)
return;
if (!dev)
return;

if (!dev->msix_enabled)
return;

pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (!pos)
return;
Expand All @@ -861,31 +839,25 @@ void pci_disable_msix(struct pci_dev* dev)

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);
}
irq = head = dev->first_msi_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);
}
dev->first_msi_irq = 0;
}

/**
Expand All @@ -899,30 +871,28 @@ void pci_disable_msix(struct pci_dev* dev)
**/
void msi_remove_pci_irq_vectors(struct pci_dev* dev)
{
int pos, temp;
int pos;
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)) {
if (pos > 0 && dev->msi_enabled) {
if (irq_has_action(dev->first_msi_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));
pci_name(dev), dev->first_msi_irq);
BUG_ON(irq_has_action(dev->first_msi_irq));
} else /* Release MSI irq assigned to this device */
msi_free_irq(dev, dev->irq);
dev->irq = temp; /* Restore IOAPIC IRQ */
msi_free_irq(dev, dev->first_msi_irq);
}
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (pos > 0 && !msi_lookup_irq(dev, PCI_CAP_ID_MSIX)) {
if (pos > 0 && dev->msix_enabled) {
int irq, head, tail = 0, warning = 0;
void __iomem *base = NULL;

irq = head = dev->irq;
irq = head = dev->first_msi_irq;
while (head != tail) {
spin_lock_irqsave(&msi_lock, flags);
tail = msi_desc[irq]->link.tail;
Expand All @@ -942,7 +912,6 @@ void msi_remove_pci_irq_vectors(struct pci_dev* dev)
pci_name(dev));
BUG_ON(warning > 0);
}
dev->irq = temp; /* Restore IOAPIC IRQ */
}
}

Expand Down
3 changes: 3 additions & 0 deletions include/linux/pci.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -174,6 +174,9 @@ struct pci_dev {
struct bin_attribute *rom_attr; /* attribute descriptor for sysfs ROM entry */
int rom_attr_enabled; /* has display of the rom attribute been enabled? */
struct bin_attribute *res_attr[DEVICE_COUNT_RESOURCE]; /* sysfs file for resources */
#ifdef CONFIG_PCI_MSI
unsigned int first_msi_irq;
#endif
};

#define pci_dev_g(n) list_entry(n, struct pci_dev, global_list)
Expand Down

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