From a52e2e3513d4beafe8fe8699f1519b021c2d05ba Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rjw@sisk.pl>
Date: Sat, 24 Jan 2009 00:21:14 +0100
Subject: [PATCH] PCI/MSI: Introduce pci_msix_table_size()
Introduce new function pci_msix_table_size() returning the size of
the MSI-X table of given PCI device or 0 if the device doesn't
support MSI-X.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
drivers/pci/msi.c | 24 +++++++++++++++++++-----
include/linux/pci.h | 5 +++++
2 files changed, 24 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index baba2eb5367df..08aedd5875b0b 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -674,6 +674,23 @@ static int msi_free_irqs(struct pci_dev* dev)
return 0;
}
+/**
+ * pci_msix_table_size - return the number of device's MSI-X table entries
+ * @dev: pointer to the pci_dev data structure of MSI-X device function
+ */
+int pci_msix_table_size(struct pci_dev *dev)
+{
+ int pos;
+ u16 control;
+
+ pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
+ if (!pos)
+ return 0;
+
+ pci_read_config_word(dev, msi_control_reg(pos), &control);
+ return multi_msix_capable(control);
+}
+
/**
* pci_enable_msix - configure device's MSI-X capability structure
* @dev: pointer to the pci_dev data structure of MSI-X device function
@@ -691,9 +708,8 @@ static int msi_free_irqs(struct pci_dev* dev)
**/
int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
{
- int status, pos, nr_entries;
+ int status, nr_entries;
int i, j;
- u16 control;
if (!entries)
return -EINVAL;
@@ -702,9 +718,7 @@ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
if (status)
return status;
- pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
- pci_read_config_word(dev, msi_control_reg(pos), &control);
- nr_entries = multi_msix_capable(control);
+ nr_entries = pci_msix_table_size(dev);
if (nvec > nr_entries)
return -EINVAL;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 7bd624bfdcfd3..b5d6d0e0f1cb1 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -799,6 +799,10 @@ static inline void pci_msi_shutdown(struct pci_dev *dev)
static inline void pci_disable_msi(struct pci_dev *dev)
{ }
+static inline int pci_msix_table_size(struct pci_dev *dev)
+{
+ return 0;
+}
static inline int pci_enable_msix(struct pci_dev *dev,
struct msix_entry *entries, int nvec)
{
@@ -823,6 +827,7 @@ static inline int pci_msi_enabled(void)
extern int pci_enable_msi(struct pci_dev *dev);
extern void pci_msi_shutdown(struct pci_dev *dev);
extern void pci_disable_msi(struct pci_dev *dev);
+extern int pci_msix_table_size(struct pci_dev *dev);
extern int pci_enable_msix(struct pci_dev *dev,
struct msix_entry *entries, int nvec);
extern void pci_msix_shutdown(struct pci_dev *dev);
--
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