From: Rafael J. Wysocki <rjw@sisk.pl>
Date: Fri, 23 Jan 2009 23:21:14 +0000 (+0100)
Subject: PCI/MSI: Introduce pci_msix_table_size()
X-Git-Tag: v2.6.30-rc1~419^2~76
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a52e2e3513d4beafe8fe8699f1519b021c2d05ba;p=platform%2Fkernel%2Flinux-exynos.git

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>
---

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index baba2eb..08aedd5 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -675,6 +675,23 @@ static int msi_free_irqs(struct pci_dev* dev)
 }
 
 /**
+ * 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
  * @entries: pointer to an array of MSI-X entries
@@ -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 7bd624b..b5d6d0e 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);