[PATCH 1/6] msi: Kill msi_lookup_irq
Eric W. Biederman
ebiederm at xmission.com
Mon Jan 29 06:42:52 EST 2007
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 at xmission.com>
---
drivers/pci/msi.c | 149 ++++++++++++++++++++-------------------------------
include/linux/pci.h | 3 +
2 files changed, 62 insertions(+), 90 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index bca5a8a..71080c9 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -283,28 +283,6 @@ void pci_disable_device_msi(struct pci_dev *dev)
PCI_CAP_ID_MSIX);
}
-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)
{
@@ -375,11 +353,13 @@ 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;
@@ -397,13 +377,7 @@ 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;
@@ -413,7 +387,6 @@ 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);
@@ -439,9 +412,11 @@ 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;
@@ -454,10 +429,7 @@ 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);
@@ -465,7 +437,6 @@ static void __pci_restore_msix_state(struct pci_dev *dev)
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);
@@ -535,6 +506,7 @@ 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);
@@ -631,6 +603,7 @@ 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);
@@ -678,13 +651,11 @@ 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;
@@ -693,15 +664,14 @@ 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);
@@ -720,6 +690,9 @@ 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;
@@ -728,28 +701,30 @@ 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)
@@ -808,7 +783,7 @@ 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)
@@ -836,16 +811,14 @@ 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);
@@ -854,7 +827,9 @@ 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)
@@ -862,6 +837,9 @@ void pci_disable_msix(struct pci_dev* dev)
if (!dev)
return;
+ if (!dev->msix_enabled)
+ return;
+
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (!pos)
return;
@@ -872,31 +850,25 @@ 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;
}
/**
@@ -910,30 +882,28 @@ 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;
@@ -953,7 +923,6 @@ void msi_remove_pci_irq_vectors(struct pci_dev* dev)
pci_name(dev));
BUG_ON(warning > 0);
}
- dev->irq = temp; /* Restore IOAPIC IRQ */
}
}
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 29765e2..1507f8c 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -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)
--
1.4.4.1.g278f
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