Merge branch 'pci/enumeration' into next

* pci/enumeration:
  PCI: Enable ECRC only if device supports it
  PCI: Add sysfs max_link_speed/width, current_link_speed/width, etc
  PCI: Test INTx masking during enumeration, not at run-time

drivers/pci/pci-sysfs.c

@@ -154,6 +154,129 @@ static ssize_t resource_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(resource);
 
+static ssize_t max_link_speed_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	u32 linkcap;
+	int err;
+	const char *speed;
+
+	err = pcie_capability_read_dword(pci_dev, PCI_EXP_LNKCAP, &linkcap);
+	if (err)
+		return -EINVAL;
+
+	switch (linkcap & PCI_EXP_LNKCAP_SLS) {
+	case PCI_EXP_LNKCAP_SLS_8_0GB:
+		speed = "8 GT/s";
+		break;
+	case PCI_EXP_LNKCAP_SLS_5_0GB:
+		speed = "5 GT/s";
+		break;
+	case PCI_EXP_LNKCAP_SLS_2_5GB:
+		speed = "2.5 GT/s";
+		break;
+	default:
+		speed = "Unknown speed";
+	}
+
+	return sprintf(buf, "%s\n", speed);
+}
+static DEVICE_ATTR_RO(max_link_speed);
+
+static ssize_t max_link_width_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	u32 linkcap;
+	int err;
+
+	err = pcie_capability_read_dword(pci_dev, PCI_EXP_LNKCAP, &linkcap);
+	if (err)
+		return -EINVAL;
+
+	return sprintf(buf, "%u\n", (linkcap & PCI_EXP_LNKCAP_MLW) >> 4);
+}
+static DEVICE_ATTR_RO(max_link_width);
+
+static ssize_t current_link_speed_show(struct device *dev,
+				       struct device_attribute *attr, char *buf)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	u16 linkstat;
+	int err;
+	const char *speed;
+
+	err = pcie_capability_read_word(pci_dev, PCI_EXP_LNKSTA, &linkstat);
+	if (err)
+		return -EINVAL;
+
+	switch (linkstat & PCI_EXP_LNKSTA_CLS) {
+	case PCI_EXP_LNKSTA_CLS_8_0GB:
+		speed = "8 GT/s";
+		break;
+	case PCI_EXP_LNKSTA_CLS_5_0GB:
+		speed = "5 GT/s";
+		break;
+	case PCI_EXP_LNKSTA_CLS_2_5GB:
+		speed = "2.5 GT/s";
+		break;
+	default:
+		speed = "Unknown speed";
+	}
+
+	return sprintf(buf, "%s\n", speed);
+}
+static DEVICE_ATTR_RO(current_link_speed);
+
+static ssize_t current_link_width_show(struct device *dev,
+				       struct device_attribute *attr, char *buf)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	u16 linkstat;
+	int err;
+
+	err = pcie_capability_read_word(pci_dev, PCI_EXP_LNKSTA, &linkstat);
+	if (err)
+		return -EINVAL;
+
+	return sprintf(buf, "%u\n",
+		(linkstat & PCI_EXP_LNKSTA_NLW) >> PCI_EXP_LNKSTA_NLW_SHIFT);
+}
+static DEVICE_ATTR_RO(current_link_width);
+
+static ssize_t secondary_bus_number_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	u8 sec_bus;
+	int err;
+
+	err = pci_read_config_byte(pci_dev, PCI_SECONDARY_BUS, &sec_bus);
+	if (err)
+		return -EINVAL;
+
+	return sprintf(buf, "%u\n", sec_bus);
+}
+static DEVICE_ATTR_RO(secondary_bus_number);
+
+static ssize_t subordinate_bus_number_show(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	struct pci_dev *pci_dev = to_pci_dev(dev);
+	u8 sub_bus;
+	int err;
+
+	err = pci_read_config_byte(pci_dev, PCI_SUBORDINATE_BUS, &sub_bus);
+	if (err)
+		return -EINVAL;
+
+	return sprintf(buf, "%u\n", sub_bus);
+}
+static DEVICE_ATTR_RO(subordinate_bus_number);
+
 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 			     char *buf)
 {
@@ -629,12 +752,17 @@ static struct attribute *pci_dev_attrs[] = {
 	NULL,
 };
 
-static const struct attribute_group pci_dev_group = {
-	.attrs = pci_dev_attrs,
+static struct attribute *pci_bridge_attrs[] = {
+	&dev_attr_subordinate_bus_number.attr,
+	&dev_attr_secondary_bus_number.attr,
+	NULL,
 };
 
-const struct attribute_group *pci_dev_groups[] = {
-	&pci_dev_group,
+static struct attribute *pcie_dev_attrs[] = {
+	&dev_attr_current_link_speed.attr,
+	&dev_attr_current_link_width.attr,
+	&dev_attr_max_link_width.attr,
+	&dev_attr_max_link_speed.attr,
 	NULL,
 };
 
@@ -1557,6 +1685,57 @@ static umode_t pci_dev_hp_attrs_are_visible(struct kobject *kobj,
 	return a->mode;
 }
 
+static umode_t pci_bridge_attrs_are_visible(struct kobject *kobj,
+					    struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	if (pci_is_bridge(pdev))
+		return a->mode;
+
+	return 0;
+}
+
+static umode_t pcie_dev_attrs_are_visible(struct kobject *kobj,
+					  struct attribute *a, int n)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	if (pci_is_pcie(pdev))
+		return a->mode;
+
+	return 0;
+}
+
+static const struct attribute_group pci_dev_group = {
+	.attrs = pci_dev_attrs,
+};
+
+const struct attribute_group *pci_dev_groups[] = {
+	&pci_dev_group,
+	NULL,
+};
+
+static const struct attribute_group pci_bridge_group = {
+	.attrs = pci_bridge_attrs,
+};
+
+const struct attribute_group *pci_bridge_groups[] = {
+	&pci_bridge_group,
+	NULL,
+};
+
+static const struct attribute_group pcie_dev_group = {
+	.attrs = pcie_dev_attrs,
+};
+
+const struct attribute_group *pcie_dev_groups[] = {
+	&pcie_dev_group,
+	NULL,
+};
+
 static struct attribute_group pci_dev_hp_attr_group = {
 	.attrs = pci_dev_hp_attrs,
 	.is_visible = pci_dev_hp_attrs_are_visible,
@@ -1592,12 +1771,24 @@ static struct attribute_group pci_dev_attr_group = {
 	.is_visible = pci_dev_attrs_are_visible,
 };
 
+static struct attribute_group pci_bridge_attr_group = {
+	.attrs = pci_bridge_attrs,
+	.is_visible = pci_bridge_attrs_are_visible,
+};
+
+static struct attribute_group pcie_dev_attr_group = {
+	.attrs = pcie_dev_attrs,
+	.is_visible = pcie_dev_attrs_are_visible,
+};
+
 static const struct attribute_group *pci_dev_attr_groups[] = {
 	&pci_dev_attr_group,
 	&pci_dev_hp_attr_group,
 #ifdef CONFIG_PCI_IOV
 	&sriov_dev_attr_group,
 #endif
+	&pci_bridge_attr_group,
+	&pcie_dev_attr_group,
 	NULL,
 };
 

drivers/pci/pci.c

@@ -3708,46 +3708,6 @@ void pci_intx(struct pci_dev *pdev, int enable)
 }
 EXPORT_SYMBOL_GPL(pci_intx);
 
-/**
- * pci_intx_mask_supported - probe for INTx masking support
- * @dev: the PCI device to operate on
- *
- * Check if the device dev support INTx masking via the config space
- * command word.
- */
-bool pci_intx_mask_supported(struct pci_dev *dev)
-{
-	bool mask_supported = false;
-	u16 orig, new;
-
-	if (dev->broken_intx_masking)
-		return false;
-
-	pci_cfg_access_lock(dev);
-
-	pci_read_config_word(dev, PCI_COMMAND, &orig);
-	pci_write_config_word(dev, PCI_COMMAND,
-			      orig ^ PCI_COMMAND_INTX_DISABLE);
-	pci_read_config_word(dev, PCI_COMMAND, &new);
-
-	/*
-	 * There's no way to protect against hardware bugs or detect them
-	 * reliably, but as long as we know what the value should be, let's
-	 * go ahead and check it.
-	 */
-	if ((new ^ orig) & ~PCI_COMMAND_INTX_DISABLE) {
-		dev_err(&dev->dev, "Command register changed from 0x%x to 0x%x: driver or hardware bug?\n",
-			orig, new);
-	} else if ((new ^ orig) & PCI_COMMAND_INTX_DISABLE) {
-		mask_supported = true;
-		pci_write_config_word(dev, PCI_COMMAND, orig);
-	}
-
-	pci_cfg_access_unlock(dev);
-	return mask_supported;
-}
-EXPORT_SYMBOL_GPL(pci_intx_mask_supported);
-
 static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask)
 {
 	struct pci_bus *bus = dev->bus;
@@ -3798,7 +3758,7 @@ static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask)
  * @dev: the PCI device to operate on
  *
  * Check if the device dev has its INTx line asserted, mask it and
- * return true in that case. False is returned if not interrupt was
+ * return true in that case. False is returned if no interrupt was
  * pending.
  */
 bool pci_check_and_mask_intx(struct pci_dev *dev)

drivers/pci/probe.c

@@ -1329,6 +1329,34 @@ static void pci_msi_setup_pci_dev(struct pci_dev *dev)
 		pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
 }
 
+/**
+ * pci_intx_mask_broken - test PCI_COMMAND_INTX_DISABLE writability
+ * @dev: PCI device
+ *
+ * Test whether PCI_COMMAND_INTX_DISABLE is writable for @dev.  Check this
+ * at enumeration-time to avoid modifying PCI_COMMAND at run-time.
+ */
+static int pci_intx_mask_broken(struct pci_dev *dev)
+{
+	u16 orig, toggle, new;
+
+	pci_read_config_word(dev, PCI_COMMAND, &orig);
+	toggle = orig ^ PCI_COMMAND_INTX_DISABLE;
+	pci_write_config_word(dev, PCI_COMMAND, toggle);
+	pci_read_config_word(dev, PCI_COMMAND, &new);
+
+	pci_write_config_word(dev, PCI_COMMAND, orig);
+
+	/*
+	 * PCI_COMMAND_INTX_DISABLE was reserved and read-only prior to PCI
+	 * r2.3, so strictly speaking, a device is not *broken* if it's not
+	 * writable.  But we'll live with the misnomer for now.
+	 */
+	if (new != toggle)
+		return 1;
+	return 0;
+}
+
 /**
  * pci_setup_device - fill in class and map information of a device
  * @dev: the device structure to fill
@@ -1399,6 +1427,8 @@ int pci_setup_device(struct pci_dev *dev)
 		}
 	}
 
+	dev->broken_intx_masking = pci_intx_mask_broken(dev);
+
 	switch (dev->hdr_type) {		    /* header type */
 	case PCI_HEADER_TYPE_NORMAL:		    /* standard header */
 		if (class == PCI_CLASS_BRIDGE_PCI)
@@ -1674,6 +1704,11 @@ static void program_hpp_type2(struct pci_dev *dev, struct hpp_type2 *hpp)
 	/* Initialize Advanced Error Capabilities and Control Register */
 	pci_read_config_dword(dev, pos + PCI_ERR_CAP, &reg32);
 	reg32 = (reg32 & hpp->adv_err_cap_and) | hpp->adv_err_cap_or;
+	/* Don't enable ECRC generation or checking if unsupported */
+	if (!(reg32 & PCI_ERR_CAP_ECRC_GENC))
+		reg32 &= ~PCI_ERR_CAP_ECRC_GENE;
+	if (!(reg32 & PCI_ERR_CAP_ECRC_CHKC))
+		reg32 &= ~PCI_ERR_CAP_ECRC_CHKE;
 	pci_write_config_dword(dev, pos + PCI_ERR_CAP, reg32);
 
 	/*

include/linux/pci.h

@@ -366,7 +366,7 @@ struct pci_dev {
 	unsigned int	is_thunderbolt:1; /* Thunderbolt controller */
 	unsigned int    __aer_firmware_first_valid:1;
 	unsigned int	__aer_firmware_first:1;
-	unsigned int	broken_intx_masking:1;
+	unsigned int	broken_intx_masking:1; /* INTx masking can't be used */
 	unsigned int	io_window_1k:1;	/* Intel P2P bridge 1K I/O windows */
 	unsigned int	irq_managed:1;
 	unsigned int	has_secondary_link:1;
@@ -1003,6 +1003,15 @@ int __must_check pci_reenable_device(struct pci_dev *);
 int __must_check pcim_enable_device(struct pci_dev *pdev);
 void pcim_pin_device(struct pci_dev *pdev);
 
+static inline bool pci_intx_mask_supported(struct pci_dev *pdev)
+{
+	/*
+	 * INTx masking is supported if PCI_COMMAND_INTX_DISABLE is
+	 * writable and no quirk has marked the feature broken.
+	 */
+	return !pdev->broken_intx_masking;
+}
+
 static inline int pci_is_enabled(struct pci_dev *pdev)
 {
 	return (atomic_read(&pdev->enable_cnt) > 0);
@@ -1026,7 +1035,6 @@ int __must_check pci_set_mwi(struct pci_dev *dev);
 int pci_try_set_mwi(struct pci_dev *dev);
 void pci_clear_mwi(struct pci_dev *dev);
 void pci_intx(struct pci_dev *dev, int enable);
-bool pci_intx_mask_supported(struct pci_dev *dev);
 bool pci_check_and_mask_intx(struct pci_dev *dev);
 bool pci_check_and_unmask_intx(struct pci_dev *dev);
 int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask);

include/uapi/linux/pci_regs.h

@@ -517,6 +517,7 @@
 #define  PCI_EXP_LNKCAP_SLS	0x0000000f /* Supported Link Speeds */
 #define  PCI_EXP_LNKCAP_SLS_2_5GB 0x00000001 /* LNKCAP2 SLS Vector bit 0 */
 #define  PCI_EXP_LNKCAP_SLS_5_0GB 0x00000002 /* LNKCAP2 SLS Vector bit 1 */
+#define  PCI_EXP_LNKCAP_SLS_8_0GB 0x00000003 /* LNKCAP2 SLS Vector bit 2 */
 #define  PCI_EXP_LNKCAP_MLW	0x000003f0 /* Maximum Link Width */
 #define  PCI_EXP_LNKCAP_ASPMS	0x00000c00 /* ASPM Support */
 #define  PCI_EXP_LNKCAP_L0SEL	0x00007000 /* L0s Exit Latency */