PCI: Refactor pci_reset_function()

Separate out function level reset so that pci_reset_function can be more easily extended. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

PCI: Refactor pci_reset_function()
Separate out function level reset so that pci_reset_function can be more easily extended. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Sheng Yang · Jesse Barnes
1 parent 1a9271331a
Showing 1 changed file with 40 additions and 26 deletions Side-by-side Diff
drivers/pci/pci.c
@@ -1751,24 +1751,7 @@
 EXPORT_SYMBOL(pci_set_dma_seg_boundary);
 #endif
  
-/**
- * pci_execute_reset_function() - Reset a PCI device function
- * @dev: Device function to reset
- *
- * Some devices allow an individual function to be reset without affecting
- * other functions in the same device.  The PCI device must be responsive
- * to PCI config space in order to use this function.
- *
- * The device function is presumed to be unused when this function is called.
- * Resetting the device will make the contents of PCI configuration space
- * random, so any caller of this must be prepared to reinitialise the
- * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
- * etc.
- *
- * Returns 0 if the device function was successfully reset or -ENOTTY if the
- * device doesn't support resetting a single function.
- */
-int pci_execute_reset_function(struct pci_dev *dev)
+static int __pcie_flr(struct pci_dev *dev, int probe)
 {
 	u16 status;
 	u32 cap;
@@ -1780,6 +1763,9 @@
 	if (!(cap & PCI_EXP_DEVCAP_FLR))
 		return -ENOTTY;
  
+	if (probe)
+		return 0;
+
 	pci_block_user_cfg_access(dev);
  
 	/* Wait for Transaction Pending bit clean */
@@ -1802,6 +1788,39 @@
 	pci_unblock_user_cfg_access(dev);
 	return 0;
 }
+
+static int __pci_reset_function(struct pci_dev *pdev, int probe)
+{
+	int res;
+
+	res = __pcie_flr(pdev, probe);
+	if (res != -ENOTTY)
+		return res;
+
+	return res;
+}
+
+/**
+ * pci_execute_reset_function() - Reset a PCI device function
+ * @dev: Device function to reset
+ *
+ * Some devices allow an individual function to be reset without affecting
+ * other functions in the same device.  The PCI device must be responsive
+ * to PCI config space in order to use this function.
+ *
+ * The device function is presumed to be unused when this function is called.
+ * Resetting the device will make the contents of PCI configuration space
+ * random, so any caller of this must be prepared to reinitialise the
+ * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
+ * etc.
+ *
+ * Returns 0 if the device function was successfully reset or -ENOTTY if the
+ * device doesn't support resetting a single function.
+ */
+int pci_execute_reset_function(struct pci_dev *dev)
+{
+	return __pci_reset_function(dev, 0);
+}
 EXPORT_SYMBOL_GPL(pci_execute_reset_function);
  
 /**
  
@@ -1822,15 +1841,10 @@
  */
 int pci_reset_function(struct pci_dev *dev)
 {
-	u32 cap;
-	int exppos = pci_find_capability(dev, PCI_CAP_ID_EXP);
-	int r;
+	int r = __pci_reset_function(dev, 1);
  
-	if (!exppos)
-		return -ENOTTY;
-	pci_read_config_dword(dev, exppos + PCI_EXP_DEVCAP, &cap);
-	if (!(cap & PCI_EXP_DEVCAP_FLR))
-		return -ENOTTY;
+	if (r < 0)
+		return r;
  
 	if (!dev->msi_enabled && !dev->msix_enabled && dev->irq != 0)
 		disable_irq(dev->irq);
...	...	@@ -1751,24 +1751,7 @@
1751	1751	EXPORT_SYMBOL(pci_set_dma_seg_boundary);
1752	1752	#endif
1753	1753
1754		-/**
1755		- * pci_execute_reset_function() - Reset a PCI device function
1756		- * @dev: Device function to reset
1757		- *
1758		- * Some devices allow an individual function to be reset without affecting
1759		- * other functions in the same device. The PCI device must be responsive
1760		- * to PCI config space in order to use this function.
1761		- *
1762		- * The device function is presumed to be unused when this function is called.
1763		- * Resetting the device will make the contents of PCI configuration space
1764		- * random, so any caller of this must be prepared to reinitialise the
1765		- * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
1766		- * etc.
1767		- *
1768		- * Returns 0 if the device function was successfully reset or -ENOTTY if the
1769		- * device doesn't support resetting a single function.
1770		- */
1771		-int pci_execute_reset_function(struct pci_dev *dev)
	1754	+static int __pcie_flr(struct pci_dev *dev, int probe)
1772	1755	{
1773	1756	u16 status;
1774	1757	u32 cap;
...	...	@@ -1780,6 +1763,9 @@
1780	1763	if (!(cap & PCI_EXP_DEVCAP_FLR))
1781	1764	return -ENOTTY;
1782	1765
	1766	+ if (probe)
	1767	+ return 0;
	1768	+
1783	1769	pci_block_user_cfg_access(dev);
1784	1770
1785	1771	/* Wait for Transaction Pending bit clean */
...	...	@@ -1802,6 +1788,39 @@
1802	1788	pci_unblock_user_cfg_access(dev);
1803	1789	return 0;
1804	1790	}
	1791	+
	1792	+static int __pci_reset_function(struct pci_dev *pdev, int probe)
	1793	+{
	1794	+ int res;
	1795	+
	1796	+ res = __pcie_flr(pdev, probe);
	1797	+ if (res != -ENOTTY)
	1798	+ return res;
	1799	+
	1800	+ return res;
	1801	+}
	1802	+
	1803	+/**
	1804	+ * pci_execute_reset_function() - Reset a PCI device function
	1805	+ * @dev: Device function to reset
	1806	+ *
	1807	+ * Some devices allow an individual function to be reset without affecting
	1808	+ * other functions in the same device. The PCI device must be responsive
	1809	+ * to PCI config space in order to use this function.
	1810	+ *
	1811	+ * The device function is presumed to be unused when this function is called.
	1812	+ * Resetting the device will make the contents of PCI configuration space
	1813	+ * random, so any caller of this must be prepared to reinitialise the
	1814	+ * device including MSI, bus mastering, BARs, decoding IO and memory spaces,
	1815	+ * etc.
	1816	+ *
	1817	+ * Returns 0 if the device function was successfully reset or -ENOTTY if the
	1818	+ * device doesn't support resetting a single function.
	1819	+ */
	1820	+int pci_execute_reset_function(struct pci_dev *dev)
	1821	+{
	1822	+ return __pci_reset_function(dev, 0);
	1823	+}
1805	1824	EXPORT_SYMBOL_GPL(pci_execute_reset_function);
1806	1825
1807	1826	/**
1808	1827
...	...	@@ -1822,15 +1841,10 @@
1822	1841	*/
1823	1842	int pci_reset_function(struct pci_dev *dev)
1824	1843	{
1825		- u32 cap;
1826		- int exppos = pci_find_capability(dev, PCI_CAP_ID_EXP);
1827		- int r;
	1844	+ int r = __pci_reset_function(dev, 1);
1828	1845
1829		- if (!exppos)
1830		- return -ENOTTY;
1831		- pci_read_config_dword(dev, exppos + PCI_EXP_DEVCAP, &cap);
1832		- if (!(cap & PCI_EXP_DEVCAP_FLR))
1833		- return -ENOTTY;
	1846	+ if (r < 0)
	1847	+ return r;
1834	1848
1835	1849	if (!dev->msi_enabled && !dev->msix_enabled && dev->irq != 0)
1836	1850	disable_irq(dev->irq);