PCI: pcie: Add support for setting default ASPM policy

Distributions may wish to provide different defaults for PCIE ASPM
depending on their target audience. Provide a configuration option for
choosing the default policy.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/pcie/Kconfig

@@ -55,6 +55,31 @@ config PCIEASPM_DEBUG
 	  This enables PCI Express ASPM debug support. It will add per-device
 	  interface to control ASPM.
 
+choice
+	prompt "Default ASPM policy"
+	default PCIEASPM_DEFAULT
+	depends on PCIEASPM
+
+config PCIEASPM_DEFAULT
+        bool "BIOS default"
+	depends on PCIEASPM
+	help
+	  Use the BIOS defaults for PCI Express ASPM.
+
+config PCIEASPM_POWERSAVE
+        bool "Powersave"
+	depends on PCIEASPM
+	help
+	  Enable PCI Express ASPM L0s and L1 where possible, even if the
+	  BIOS did not.
+
+config PCIEASPM_PERFORMANCE
+        bool "Performance"
+	depends on PCIEASPM
+	help
+	  Disable PCI Express ASPM L0s and L1, even if the BIOS enabled them.
+endchoice
+
 config PCIE_PME
 	def_bool y
 	depends on PCIEPORTBUS && PM_RUNTIME && EXPERIMENTAL && ACPI

drivers/pci/pcie/aspm.c

@@ -76,7 +76,15 @@ static LIST_HEAD(link_list);
 #define POLICY_DEFAULT 0	/* BIOS default setting */
 #define POLICY_PERFORMANCE 1	/* high performance */
 #define POLICY_POWERSAVE 2	/* high power saving */
+
+#ifdef CONFIG_PCIEASPM_PERFORMANCE
+static int aspm_policy = POLICY_PERFORMANCE;
+#elif defined CONFIG_PCIEASPM_POWERSAVE
+static int aspm_policy = POLICY_POWERSAVE;
+#else
 static int aspm_policy;
+#endif
+
 static const char *policy_str[] = {
 	[POLICY_DEFAULT] = "default",
 	[POLICY_PERFORMANCE] = "performance",