ACPI/PCI: PCIe ASPM _OSC support capabilities called when root bridge added

The _OSC capabilities OSC_ACTIVE_STATE_PWR_SUPPORT and
OSC_CLOCK_PWR_CAPABILITY_SUPPORT are set when the root bridge is added
with pci_acpi_osc_support(), so we no longer need to do it in the ASPM
driver.  Also add the function pcie_aspm_enabled, which returns true if
pcie_aspm=off is not on the kernel command-line.
Signed-off-by: Andrew Patterson <andrew.patterson@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

drivers/acpi/pci_root.c

@@ -347,6 +347,9 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 	/* Indicate support for various _OSC capabilities. */
 	if (pci_ext_cfg_avail(root->bus->self))
 		flags |= OSC_EXT_PCI_CONFIG_SUPPORT;
+	if (pcie_aspm_enabled())
+		flags |= OSC_ACTIVE_STATE_PWR_SUPPORT |
+			OSC_CLOCK_PWR_CAPABILITY_SUPPORT;
 	if (flags != base_flags)
 		pci_acpi_osc_support(device->handle, flags);
 

drivers/pci/pcie/aspm.c

@@ -857,24 +857,15 @@ void pcie_no_aspm(void)
 		aspm_disabled = 1;
 }
 
-#ifdef CONFIG_ACPI
-#include <acpi/acpi_bus.h>
-#include <linux/pci-acpi.h>
-static void pcie_aspm_platform_init(void)
-{
-	pcie_osc_support_set(OSC_ACTIVE_STATE_PWR_SUPPORT|
-		OSC_CLOCK_PWR_CAPABILITY_SUPPORT);
-}
-#else
-static inline void pcie_aspm_platform_init(void) { }
-#endif
-
-static int __init pcie_aspm_init(void)
+/**
+ * pcie_aspm_enabled - is PCIe ASPM enabled?
+ *
+ * Returns true if ASPM has not been disabled by the command-line option
+ * pcie_aspm=off.
+ **/
+int pcie_aspm_enabled(void)
 {
-	if (aspm_disabled)
-		return 0;
-	pcie_aspm_platform_init();
-	return 0;
+       return !aspm_disabled;
 }
+EXPORT_SYMBOL(pcie_aspm_enabled);
 
-fs_initcall(pcie_aspm_init);

include/linux/pci.h

@@ -791,6 +791,15 @@ extern void msi_remove_pci_irq_vectors(struct pci_dev *dev);
 extern void pci_restore_msi_state(struct pci_dev *dev);
 #endif
 
+#ifndef CONFIG_PCIEASPM
+static inline int pcie_aspm_enabled(void)
+{
+	return 0;
+}
+#else
+extern int pcie_aspm_enabled(void);
+#endif
+
 #ifdef CONFIG_HT_IRQ
 /* The functions a driver should call */
 int  ht_create_irq(struct pci_dev *dev, int idx);