[PATCH] genirq: msi: simplify msi enable and disable
The problem. Because the disable routines leave the msi interrupts in all
sorts of half enabled states the enable routines become impossible to
implement correctly, and almost impossible to understand.
Simplifing this allows me to simply kill the buggy reroute_msix_table, and
generally makes the code more maintainable.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rajesh Shah <rajesh.shah@intel.com>
Cc: Andi Kleen <ak@muc.de>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@UNISYS.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Rajesh Shah <rajesh.shah@intel.com>
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 27a0574..75d1c0d 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -933,7 +933,6 @@
int pci_enable_msi(struct pci_dev* dev)
{
int pos, temp, status;
- u16 control;
if (pci_msi_supported(dev) < 0)
return -EINVAL;
@@ -948,27 +947,8 @@
if (!pos)
return -EINVAL;
- if (!msi_lookup_vector(dev, PCI_CAP_ID_MSI)) {
- /* Lookup Sucess */
- unsigned long flags;
+ WARN_ON(!msi_lookup_vector(dev, PCI_CAP_ID_MSI));
- pci_read_config_word(dev, msi_control_reg(pos), &control);
- if (control & PCI_MSI_FLAGS_ENABLE)
- return 0; /* Already in MSI mode */
- spin_lock_irqsave(&msi_lock, flags);
- if (!vector_irq[dev->irq]) {
- msi_desc[dev->irq]->msi_attrib.state = 0;
- vector_irq[dev->irq] = -1;
- nr_released_vectors--;
- spin_unlock_irqrestore(&msi_lock, flags);
- status = msi_register_init(dev, msi_desc[dev->irq]);
- if (status == 0)
- enable_msi_mode(dev, pos, PCI_CAP_ID_MSI);
- return status;
- }
- spin_unlock_irqrestore(&msi_lock, flags);
- dev->irq = temp;
- }
/* Check whether driver already requested for MSI-X vectors */
pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
if (pos > 0 && !msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
@@ -1010,6 +990,8 @@
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) {
@@ -1023,14 +1005,12 @@
pci_name(dev), dev->irq);
BUG_ON(entry->msi_attrib.state > 0);
} else {
- vector_irq[dev->irq] = 0; /* free it */
- nr_released_vectors++;
default_vector = entry->msi_attrib.default_vector;
spin_unlock_irqrestore(&msi_lock, flags);
+ msi_free_vector(dev, dev->irq, 0);
+
/* Restore dev->irq to its default pin-assertion vector */
dev->irq = default_vector;
- disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI),
- PCI_CAP_ID_MSI);
}
}
@@ -1078,57 +1058,6 @@
return 0;
}
-static int reroute_msix_table(int head, struct msix_entry *entries, int *nvec)
-{
- int vector = head, tail = 0;
- int i, j = 0, nr_entries = 0;
- void __iomem *base;
- unsigned long flags;
-
- spin_lock_irqsave(&msi_lock, flags);
- while (head != tail) {
- nr_entries++;
- tail = msi_desc[vector]->link.tail;
- if (entries[0].entry == msi_desc[vector]->msi_attrib.entry_nr)
- j = vector;
- vector = tail;
- }
- if (*nvec > nr_entries) {
- spin_unlock_irqrestore(&msi_lock, flags);
- *nvec = nr_entries;
- return -EINVAL;
- }
- vector = ((j > 0) ? j : head);
- for (i = 0; i < *nvec; i++) {
- j = msi_desc[vector]->msi_attrib.entry_nr;
- msi_desc[vector]->msi_attrib.state = 0; /* Mark it not active */
- vector_irq[vector] = -1; /* Mark it busy */
- nr_released_vectors--;
- entries[i].vector = vector;
- if (j != (entries + i)->entry) {
- base = msi_desc[vector]->mask_base;
- msi_desc[vector]->msi_attrib.entry_nr =
- (entries + i)->entry;
- writel( readl(base + j * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET), base +
- (entries + i)->entry * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET);
- writel( readl(base + j * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET), base +
- (entries + i)->entry * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET);
- writel( (readl(base + j * PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_DATA_OFFSET) & 0xff00) | vector,
- base + (entries+i)->entry*PCI_MSIX_ENTRY_SIZE +
- PCI_MSIX_ENTRY_DATA_OFFSET);
- }
- vector = msi_desc[vector]->link.tail;
- }
- spin_unlock_irqrestore(&msi_lock, flags);
-
- 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
@@ -1163,9 +1092,6 @@
return -EINVAL;
pci_read_config_word(dev, msi_control_reg(pos), &control);
- if (control & PCI_MSIX_FLAGS_ENABLE)
- return -EINVAL; /* Already in MSI-X mode */
-
nr_entries = multi_msix_capable(control);
if (nvec > nr_entries)
return -EINVAL;
@@ -1180,19 +1106,8 @@
}
}
temp = dev->irq;
- if (!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
- /* Lookup Sucess */
- nr_entries = nvec;
- /* Reroute MSI-X table */
- if (reroute_msix_table(dev->irq, entries, &nr_entries)) {
- /* #requested > #previous-assigned */
- dev->irq = temp;
- return nr_entries;
- }
- dev->irq = temp;
- enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
- return 0;
- }
+ WARN_ON(!msi_lookup_vector(dev, PCI_CAP_ID_MSIX));
+
/* Check whether driver already requested for MSI vector */
if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0 &&
!msi_lookup_vector(dev, PCI_CAP_ID_MSI)) {
@@ -1251,37 +1166,32 @@
if (!(control & PCI_MSIX_FLAGS_ENABLE))
return;
+ disable_msi_mode(dev, pos, PCI_CAP_ID_MSIX);
+
temp = dev->irq;
if (!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) {
int state, vector, head, tail = 0, warning = 0;
unsigned long flags;
vector = head = dev->irq;
- spin_lock_irqsave(&msi_lock, flags);
+ dev->irq = temp; /* Restore pin IRQ */
while (head != tail) {
+ spin_lock_irqsave(&msi_lock, flags);
state = msi_desc[vector]->msi_attrib.state;
+ tail = msi_desc[vector]->link.tail;
+ spin_unlock_irqrestore(&msi_lock, flags);
if (state)
warning = 1;
- else {
- vector_irq[vector] = 0; /* free it */
- nr_released_vectors++;
- }
- tail = msi_desc[vector]->link.tail;
+ else if (vector != head) /* Release MSI-X vector */
+ msi_free_vector(dev, vector, 0);
vector = tail;
}
- spin_unlock_irqrestore(&msi_lock, flags);
+ msi_free_vector(dev, vector, 0);
if (warning) {
- dev->irq = temp;
printk(KERN_WARNING "PCI: %s: pci_disable_msix() called without "
"free_irq() on all MSI-X vectors\n",
pci_name(dev));
BUG_ON(warning > 0);
- } else {
- dev->irq = temp;
- disable_msi_mode(dev,
- pci_find_capability(dev, PCI_CAP_ID_MSIX),
- PCI_CAP_ID_MSIX);
-
}
}
}