Merge branch 'pci/misc' into next

* pci/misc:
  PCI: Read capability list as dwords, not bytes
  PCI: Don't clear ASPM bits when the FADT declares it's unsupported
  PCI: Clarify policy for vendor IDs in pci.txt
  PCI/ACPI: Optimize device state transition delays
  PCI: Export pci_find_host_bridge() for use inside PCI core
  PCI: Make a shareable UUID for PCI firmware ACPI _DSM
  PCI: Fix typo in Thunderbolt kernel message

8 files changed, 106 insertions, 46 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 68a5f71..1b5569c 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -423,8 +423,7 @@ out:
 }
 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 
-static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
-				 int *clear_aspm)
+static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
 {
 	u32 support, control, requested;
 	acpi_status status;
@@ -495,10 +494,12 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
 		decode_osc_control(root, "OS now controls", control);
 		if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_ASPM) {
 			/*
-			 * We have ASPM control, but the FADT indicates
-			 * that it's unsupported. Clear it.
+			 * We have ASPM control, but the FADT indicates that
+			 * it's unsupported. Leave existing configuration
+			 * intact and prevent the OS from touching it.
 			 */
-			*clear_aspm = 1;
+			dev_info(&device->dev, "FADT indicates ASPM is unsupported, using BIOS configuration\n");
+			*no_aspm = 1;
 		}
 	} else {
 		decode_osc_control(root, "OS requested", requested);
@@ -525,7 +526,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
 	int result;
 	struct acpi_pci_root *root;
 	acpi_handle handle = device->handle;
-	int no_aspm = 0, clear_aspm = 0;
+	int no_aspm = 0;
 	bool hotadd = system_state != SYSTEM_BOOTING;
 
 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
@@ -584,7 +585,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
 
 	root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 
-	negotiate_os_control(root, &no_aspm, &clear_aspm);
+	negotiate_os_control(root, &no_aspm);
 
 	/*
 	 * TBD: Need PCI interface for enumeration/configuration of roots.
@@ -607,10 +608,6 @@ static int acpi_pci_root_add(struct acpi_device *device,
 		goto remove_dmar;
 	}
 
-	if (clear_aspm) {
-		dev_info(&device->dev, "Disabling ASPM (FADT indicates it is unsupported)\n");
-		pcie_clear_aspm(root->bus);
-	}
 	if (no_aspm)
 		pcie_no_aspm();
 
diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
index 3e5bbf9..5f4a2e0 100644
--- a/drivers/pci/host-bridge.c
+++ b/drivers/pci/host-bridge.c
@@ -16,7 +16,7 @@ static struct pci_bus *find_pci_root_bus(struct pci_bus *bus)
 	return bus;
 }
 
-static struct pci_host_bridge *find_pci_host_bridge(struct pci_bus *bus)
+struct pci_host_bridge *pci_find_host_bridge(struct pci_bus *bus)
 {
 	struct pci_bus *root_bus = find_pci_root_bus(bus);
 
@@ -48,7 +48,7 @@ void pci_set_host_bridge_release(struct pci_host_bridge *bridge,
 void pcibios_resource_to_bus(struct pci_bus *bus, struct pci_bus_region *region,
 			     struct resource *res)
 {
-	struct pci_host_bridge *bridge = find_pci_host_bridge(bus);
+	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
 	struct resource_entry *window;
 	resource_size_t offset = 0;
 
@@ -73,7 +73,7 @@ static bool region_contains(struct pci_bus_region *region1,
 void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
 			     struct pci_bus_region *region)
 {
-	struct pci_host_bridge *bridge = find_pci_host_bridge(bus);
+	struct pci_host_bridge *bridge = pci_find_host_bridge(bus);
 	struct resource_entry *window;
 	resource_size_t offset = 0;
 
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 4890639..5eba747 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -18,6 +18,15 @@
 #include <linux/pm_qos.h>
 #include "pci.h"
 
+/*
+ * The UUID is defined in the PCI Firmware Specification available here:
+ * https://www.pcisig.com/members/downloads/pcifw_r3_1_13Dec10.pdf
+ */
+const u8 pci_acpi_dsm_uuid[] = {
+	0xd0, 0x37, 0xc9, 0xe5, 0x53, 0x35, 0x7a, 0x4d,
+	0x91, 0x17, 0xea, 0x4d, 0x19, 0xc3, 0x43, 0x4d
+};
+
 phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
 {
 	acpi_status status = AE_NOT_EXIST;
@@ -528,11 +537,32 @@ static struct pci_platform_pm_ops acpi_pci_platform_pm = {
 
 void acpi_pci_add_bus(struct pci_bus *bus)
 {
+	union acpi_object *obj;
+	struct pci_host_bridge *bridge;
+
 	if (acpi_pci_disabled || !bus->bridge)
 		return;
 
 	acpi_pci_slot_enumerate(bus);
 	acpiphp_enumerate_slots(bus);
+
+	/*
+	 * For a host bridge, check its _DSM for function 8 and if
+	 * that is available, mark it in pci_host_bridge.
+	 */
+	if (!pci_is_root_bus(bus))
+		return;
+
+	obj = acpi_evaluate_dsm(ACPI_HANDLE(bus->bridge), pci_acpi_dsm_uuid, 3,
+				RESET_DELAY_DSM, NULL);
+	if (!obj)
+		return;
+
+	if (obj->type == ACPI_TYPE_INTEGER && obj->integer.value == 1) {
+		bridge = pci_find_host_bridge(bus);
+		bridge->ignore_reset_delay = 1;
+	}
+	ACPI_FREE(obj);
 }
 
 void acpi_pci_remove_bus(struct pci_bus *bus)
@@ -558,6 +588,57 @@ static struct acpi_device *acpi_pci_find_companion(struct device *dev)
 				      check_children);
 }
 
+/**
+ * pci_acpi_optimize_delay - optimize PCI D3 and D3cold delay from ACPI
+ * @pdev: the PCI device whose delay is to be updated
+ * @adev: the companion ACPI device of this PCI device
+ *
+ * Update the d3_delay and d3cold_delay of a PCI device from the ACPI _DSM
+ * control method of either the device itself or the PCI host bridge.
+ *
+ * Function 8, "Reset Delay," applies to the entire hierarchy below a PCI
+ * host bridge.  If it returns one, the OS may assume that all devices in
+ * the hierarchy have already completed power-on reset delays.
+ *
+ * Function 9, "Device Readiness Durations," applies only to the object
+ * where it is located.  It returns delay durations required after various
+ * events if the device requires less time than the spec requires.  Delays
+ * from this function take precedence over the Reset Delay function.
+ *
+ * These _DSM functions are defined by the draft ECN of January 28, 2014,
+ * titled "ACPI additions for FW latency optimizations."
+ */
+static void pci_acpi_optimize_delay(struct pci_dev *pdev,
+				    acpi_handle handle)
+{
+	struct pci_host_bridge *bridge = pci_find_host_bridge(pdev->bus);
+	int value;
+	union acpi_object *obj, *elements;
+
+	if (bridge->ignore_reset_delay)
+		pdev->d3cold_delay = 0;
+
+	obj = acpi_evaluate_dsm(handle, pci_acpi_dsm_uuid, 3,
+				FUNCTION_DELAY_DSM, NULL);
+	if (!obj)
+		return;
+
+	if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) {
+		elements = obj->package.elements;
+		if (elements[0].type == ACPI_TYPE_INTEGER) {
+			value = (int)elements[0].integer.value / 1000;
+			if (value < PCI_PM_D3COLD_WAIT)
+				pdev->d3cold_delay = value;
+		}
+		if (elements[3].type == ACPI_TYPE_INTEGER) {
+			value = (int)elements[3].integer.value / 1000;
+			if (value < PCI_PM_D3_WAIT)
+				pdev->d3_delay = value;
+		}
+	}
+	ACPI_FREE(obj);
+}
+
 static void pci_acpi_setup(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
@@ -566,6 +647,8 @@ static void pci_acpi_setup(struct device *dev)
 	if (!adev)
 		return;
 
+	pci_acpi_optimize_delay(pci_dev, adev->handle);
+
 	pci_acpi_add_pm_notifier(adev, pci_dev);
 	if (!adev->wakeup.flags.valid)
 		return;
diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c
index 2ab1b47..024b5c1 100644
--- a/drivers/pci/pci-label.c
+++ b/drivers/pci/pci-label.c
@@ -31,8 +31,6 @@
 #include <linux/pci-acpi.h>
 #include "pci.h"
 
-#define	DEVICE_LABEL_DSM	0x07
-
 #ifdef CONFIG_DMI
 enum smbios_attr_enum {
 	SMBIOS_ATTR_NONE = 0,
@@ -148,11 +146,6 @@ static inline void pci_remove_smbiosname_file(struct pci_dev *pdev)
 #endif
 
 #ifdef CONFIG_ACPI
-static const char device_label_dsm_uuid[] = {
-	0xD0, 0x37, 0xC9, 0xE5, 0x53, 0x35, 0x7A, 0x4D,
-	0x91, 0x17, 0xEA, 0x4D, 0x19, 0xC3, 0x43, 0x4D
-};
-
 enum acpi_attr_enum {
 	ACPI_ATTR_LABEL_SHOW,
 	ACPI_ATTR_INDEX_SHOW,
@@ -179,7 +172,7 @@ static int dsm_get_label(struct device *dev, char *buf,
 	if (!handle)
 		return -1;
 
-	obj = acpi_evaluate_dsm(handle, device_label_dsm_uuid, 0x2,
+	obj = acpi_evaluate_dsm(handle, pci_acpi_dsm_uuid, 0x2,
 				DEVICE_LABEL_DSM, NULL);
 	if (!obj)
 		return -1;
@@ -219,7 +212,7 @@ static bool device_has_dsm(struct device *dev)
 	if (!handle)
 		return false;
 
-	return !!acpi_check_dsm(handle, device_label_dsm_uuid, 0x2,
+	return !!acpi_check_dsm(handle, pci_acpi_dsm_uuid, 0x2,
 				1 << DEVICE_LABEL_DSM);
 }
 
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 061fdce..acc4b6e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -146,19 +146,22 @@ static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn,
 				   u8 pos, int cap, int *ttl)
 {
 	u8 id;
+	u16 ent;
+
+	pci_bus_read_config_byte(bus, devfn, pos, &pos);
 
 	while ((*ttl)--) {
-		pci_bus_read_config_byte(bus, devfn, pos, &pos);
 		if (pos < 0x40)
 			break;
 		pos &= ~3;
-		pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID,
-					 &id);
+		pci_bus_read_config_word(bus, devfn, pos, &ent);
+
+		id = ent & 0xff;
 		if (id == 0xff)
 			break;
 		if (id == cap)
 			return pos;
-		pos += PCI_CAP_LIST_NEXT;
+		pos = (ent >> 8);
 	}
 	return 0;
 }
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 4091f82..d72f849 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -321,4 +321,6 @@ static inline int pci_dev_specific_reset(struct pci_dev *dev, int probe)
 }
 #endif
 
+struct pci_host_bridge *pci_find_host_bridge(struct pci_bus *bus);
+
 #endif /* DRIVERS_PCI_H */
diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 820740a..7d4fcdc 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -782,24 +782,6 @@ void pci_disable_link_state(struct pci_dev *pdev, int state)
 }
 EXPORT_SYMBOL(pci_disable_link_state);
 
-void pcie_clear_aspm(struct pci_bus *bus)
-{
-	struct pci_dev *child;
-
-	if (aspm_force)
-		return;
-
-	/*
-	 * Clear any ASPM setup that the firmware has carried out on this bus
-	 */
-	list_for_each_entry(child, &bus->devices, bus_list) {
-		__pci_disable_link_state(child, PCIE_LINK_STATE_L0S |
-					 PCIE_LINK_STATE_L1 |
-					 PCIE_LINK_STATE_CLKPM,
-					 false, true);
-	}
-}
-
 static int pcie_aspm_set_policy(const char *val, struct kernel_param *kp)
 {
 	int i;
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 1bde397..c6dc1df 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3182,7 +3182,7 @@ static void quirk_apple_wait_for_thunderbolt(struct pci_dev *dev)
 			|| nhi->subsystem_vendor != 0x2222
 			|| nhi->subsystem_device != 0x1111)
 		goto out;
-	dev_info(&dev->dev, "quirk: wating for thunderbolt to reestablish pci tunnels...\n");
+	dev_info(&dev->dev, "quirk: waiting for thunderbolt to reestablish PCI tunnels...\n");
 	device_pm_wait_for_dev(&dev->dev, &nhi->dev);
 out:
 	pci_dev_put(nhi);