[PATCH] msi: simplify msi sanity checks by adding with generic irq code
Currently msi.c is doing sanity checks that make certain before an irq is
destroyed it has no more users.
By adding irq_has_action I can perform the test is a generic way, instead of
relying on a msi specific data structure.
By performing the core check in dynamic_irq_cleanup I ensure every user of
dynamic irqs has a test present and we don't free resources that are in use.
In msi.c this allows me to kill the attrib.state member of msi_desc and all of
the assciated code to maintain it.
To keep from freeing data structures when irq cleanup code is called to soon
changing dyanamic_irq_cleanup is insufficient because there are msi specific
data structures that are also not safe to free.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index da2c6c2..e3ba396 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -188,18 +188,6 @@
static unsigned int startup_msi_irq_wo_maskbit(unsigned int irq)
{
- struct msi_desc *entry;
- unsigned long flags;
-
- spin_lock_irqsave(&msi_lock, flags);
- entry = msi_desc[irq];
- if (!entry || !entry->dev) {
- spin_unlock_irqrestore(&msi_lock, flags);
- return 0;
- }
- entry->msi_attrib.state = 1; /* Mark it active */
- spin_unlock_irqrestore(&msi_lock, flags);
-
return 0; /* never anything pending */
}
@@ -212,14 +200,6 @@
static void shutdown_msi_irq(unsigned int irq)
{
- struct msi_desc *entry;
- unsigned long flags;
-
- spin_lock_irqsave(&msi_lock, flags);
- entry = msi_desc[irq];
- if (entry && entry->dev)
- entry->msi_attrib.state = 0; /* Mark it not active */
- spin_unlock_irqrestore(&msi_lock, flags);
}
static void end_msi_irq_wo_maskbit(unsigned int irq)
@@ -671,7 +651,6 @@
entry->link.head = irq;
entry->link.tail = irq;
entry->msi_attrib.type = PCI_CAP_ID_MSI;
- entry->msi_attrib.state = 0; /* Mark it not active */
entry->msi_attrib.is_64 = is_64bit_address(control);
entry->msi_attrib.entry_nr = 0;
entry->msi_attrib.maskbit = is_mask_bit_support(control);
@@ -744,7 +723,6 @@
j = entries[i].entry;
entries[i].vector = irq;
entry->msi_attrib.type = PCI_CAP_ID_MSIX;
- entry->msi_attrib.state = 0; /* Mark it not active */
entry->msi_attrib.is_64 = 1;
entry->msi_attrib.entry_nr = j;
entry->msi_attrib.maskbit = 1;
@@ -897,12 +875,12 @@
spin_unlock_irqrestore(&msi_lock, flags);
return;
}
- if (entry->msi_attrib.state) {
+ 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(entry->msi_attrib.state > 0);
+ BUG_ON(irq_has_action(dev->irq));
} else {
default_irq = entry->msi_attrib.default_irq;
spin_unlock_irqrestore(&msi_lock, flags);
@@ -1035,17 +1013,16 @@
temp = dev->irq;
if (!msi_lookup_irq(dev, PCI_CAP_ID_MSIX)) {
- int state, irq, head, tail = 0, warning = 0;
+ 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);
- state = msi_desc[irq]->msi_attrib.state;
tail = msi_desc[irq]->link.tail;
spin_unlock_irqrestore(&msi_lock, flags);
- if (state)
+ if (irq_has_action(irq))
warning = 1;
else if (irq != head) /* Release MSI-X irq */
msi_free_irq(dev, irq);
@@ -1072,7 +1049,7 @@
**/
void msi_remove_pci_irq_vectors(struct pci_dev* dev)
{
- int state, pos, temp;
+ int pos, temp;
unsigned long flags;
if (!pci_msi_enable || !dev)
@@ -1081,14 +1058,11 @@
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)) {
- spin_lock_irqsave(&msi_lock, flags);
- state = msi_desc[dev->irq]->msi_attrib.state;
- spin_unlock_irqrestore(&msi_lock, flags);
- if (state) {
+ 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(state > 0);
+ 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 */
@@ -1101,11 +1075,10 @@
irq = head = dev->irq;
while (head != tail) {
spin_lock_irqsave(&msi_lock, flags);
- state = msi_desc[irq]->msi_attrib.state;
tail = msi_desc[irq]->link.tail;
base = msi_desc[irq]->mask_base;
spin_unlock_irqrestore(&msi_lock, flags);
- if (state)
+ if (irq_has_action(irq))
warning = 1;
else if (irq != head) /* Release MSI-X irq */
msi_free_irq(dev, irq);
diff --git a/drivers/pci/msi.h b/drivers/pci/msi.h
index 435d05a..77823bf 100644
--- a/drivers/pci/msi.h
+++ b/drivers/pci/msi.h
@@ -53,7 +53,7 @@
struct {
__u8 type : 5; /* {0: unused, 5h:MSI, 11h:MSI-X} */
__u8 maskbit : 1; /* mask-pending bit supported ? */
- __u8 state : 1; /* {0: free, 1: busy} */
+ __u8 unused : 1;
__u8 is_64 : 1; /* Address size: 0=32bit 1=64bit */
__u8 pos; /* Location of the msi capability */
__u16 entry_nr; /* specific enabled entry */
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 69855b2..6f46360 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -372,6 +372,13 @@
extern int create_irq(void);
extern void destroy_irq(unsigned int irq);
+/* Test to see if a driver has successfully requested an irq */
+static inline int irq_has_action(unsigned int irq)
+{
+ struct irq_desc *desc = irq_desc + irq;
+ return desc->action != NULL;
+}
+
/* Dynamic irq helper functions */
extern void dynamic_irq_init(unsigned int irq);
extern void dynamic_irq_cleanup(unsigned int irq);
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 0dc2438..4cf65f5 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -67,6 +67,13 @@
desc = irq_desc + irq;
spin_lock_irqsave(&desc->lock, flags);
+ if (desc->action) {
+ spin_unlock_irqrestore(&desc->lock, flags);
+ printk(KERN_ERR "Destroying IRQ%d without calling free_irq\n",
+ irq);
+ WARN_ON(1);
+ return;
+ }
desc->handle_irq = handle_bad_irq;
desc->chip = &no_irq_chip;
spin_unlock_irqrestore(&desc->lock, flags);