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path: root/drivers/pci/msi.c
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Diffstat (limited to 'drivers/pci/msi.c')
-rw-r--r--drivers/pci/msi.c64
1 files changed, 34 insertions, 30 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index a83c1f5735d..27a057409ec 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -45,16 +45,10 @@ msi_register(struct msi_ops *ops)
return 0;
}
-static void msi_cache_ctor(void *p, kmem_cache_t *cache, unsigned long flags)
-{
- memset(p, 0, sizeof(struct msi_desc));
-}
-
static int msi_cache_init(void)
{
- msi_cachep = kmem_cache_create("msi_cache",
- sizeof(struct msi_desc),
- 0, SLAB_HWCACHE_ALIGN, msi_cache_ctor, NULL);
+ msi_cachep = kmem_cache_create("msi_cache", sizeof(struct msi_desc),
+ 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
if (!msi_cachep)
return -ENOMEM;
@@ -402,11 +396,10 @@ static struct msi_desc* alloc_msi_entry(void)
{
struct msi_desc *entry;
- entry = kmem_cache_alloc(msi_cachep, SLAB_KERNEL);
+ entry = kmem_cache_zalloc(msi_cachep, GFP_KERNEL);
if (!entry)
return NULL;
- memset(entry, 0, sizeof(struct msi_desc));
entry->link.tail = entry->link.head = 0; /* single message */
entry->dev = NULL;
@@ -901,6 +894,33 @@ static int msix_capability_init(struct pci_dev *dev,
}
/**
+ * 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
*
@@ -912,19 +932,11 @@ static int msix_capability_init(struct pci_dev *dev,
**/
int pci_enable_msi(struct pci_dev* dev)
{
- struct pci_bus *bus;
- int pos, temp, status = -EINVAL;
+ int pos, temp, status;
u16 control;
- if (!pci_msi_enable || !dev)
- return status;
-
- if (dev->no_msi)
- return status;
-
- for (bus = dev->bus; bus; bus = bus->parent)
- if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
- return -EINVAL;
+ if (pci_msi_supported(dev) < 0)
+ return -EINVAL;
temp = dev->irq;
@@ -1134,22 +1146,14 @@ static int reroute_msix_table(int head, struct msix_entry *entries, int *nvec)
**/
int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
{
- struct pci_bus *bus;
int status, pos, nr_entries, free_vectors;
int i, j, temp;
u16 control;
unsigned long flags;
- if (!pci_msi_enable || !dev || !entries)
+ if (!entries || pci_msi_supported(dev) < 0)
return -EINVAL;
- if (dev->no_msi)
- return -EINVAL;
-
- for (bus = dev->bus; bus; bus = bus->parent)
- if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
- return -EINVAL;
-
status = msi_init();
if (status < 0)
return status;