Merge branch 'pci/virtualization' into next

* pci/virtualization:
  PCI: Enable quirks for PCIe ACS on Intel PCH root ports
  PCI: Add pci_dev_flag for ACS enable quirks
  PCI: Add device-specific PCI ACS enable

drivers/pci/pci.c

@@ -2180,21 +2180,18 @@ void pci_request_acs(void)
 }
 
 /**
- * pci_enable_acs - enable ACS if hardware support it
+ * pci_std_enable_acs - enable ACS on devices using standard ACS capabilites
  * @dev: the PCI device
  */
-void pci_enable_acs(struct pci_dev *dev)
+static int pci_std_enable_acs(struct pci_dev *dev)
 {
 	int pos;
 	u16 cap;
 	u16 ctrl;
 
-	if (!pci_acs_enable)
-		return;
-
 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS);
 	if (!pos)
-		return;
+		return -ENODEV;
 
 	pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap);
 	pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl);
@@ -2212,6 +2209,23 @@ void pci_enable_acs(struct pci_dev *dev)
 	ctrl |= (cap & PCI_ACS_UF);
 
 	pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
+
+	return 0;
+}
+
+/**
+ * pci_enable_acs - enable ACS if hardware support it
+ * @dev: the PCI device
+ */
+void pci_enable_acs(struct pci_dev *dev)
+{
+	if (!pci_acs_enable)
+		return;
+
+	if (!pci_std_enable_acs(dev))
+		return;
+
+	pci_dev_specific_enable_acs(dev);
 }
 
 static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags)

drivers/pci/quirks.c

@@ -3423,6 +3423,61 @@ static int pci_quirk_amd_sb_acs(struct pci_dev *dev, u16 acs_flags)
 #endif
 }
 
+/*
+ * Many Intel PCH root ports do provide ACS-like features to disable peer
+ * transactions and validate bus numbers in requests, but do not provide an
+ * actual PCIe ACS capability.  This is the list of device IDs known to fall
+ * into that category as provided by Intel in Red Hat bugzilla 1037684.
+ */
+static const u16 pci_quirk_intel_pch_acs_ids[] = {
+	/* Ibexpeak PCH */
+	0x3b42, 0x3b43, 0x3b44, 0x3b45, 0x3b46, 0x3b47, 0x3b48, 0x3b49,
+	0x3b4a, 0x3b4b, 0x3b4c, 0x3b4d, 0x3b4e, 0x3b4f, 0x3b50, 0x3b51,
+	/* Cougarpoint PCH */
+	0x1c10, 0x1c11, 0x1c12, 0x1c13, 0x1c14, 0x1c15, 0x1c16, 0x1c17,
+	0x1c18, 0x1c19, 0x1c1a, 0x1c1b, 0x1c1c, 0x1c1d, 0x1c1e, 0x1c1f,
+	/* Pantherpoint PCH */
+	0x1e10, 0x1e11, 0x1e12, 0x1e13, 0x1e14, 0x1e15, 0x1e16, 0x1e17,
+	0x1e18, 0x1e19, 0x1e1a, 0x1e1b, 0x1e1c, 0x1e1d, 0x1e1e, 0x1e1f,
+	/* Lynxpoint-H PCH */
+	0x8c10, 0x8c11, 0x8c12, 0x8c13, 0x8c14, 0x8c15, 0x8c16, 0x8c17,
+	0x8c18, 0x8c19, 0x8c1a, 0x8c1b, 0x8c1c, 0x8c1d, 0x8c1e, 0x8c1f,
+	/* Lynxpoint-LP PCH */
+	0x9c10, 0x9c11, 0x9c12, 0x9c13, 0x9c14, 0x9c15, 0x9c16, 0x9c17,
+	0x9c18, 0x9c19, 0x9c1a, 0x9c1b,
+	/* Wildcat PCH */
+	0x9c90, 0x9c91, 0x9c92, 0x9c93, 0x9c94, 0x9c95, 0x9c96, 0x9c97,
+	0x9c98, 0x9c99, 0x9c9a, 0x9c9b,
+};
+
+static bool pci_quirk_intel_pch_acs_match(struct pci_dev *dev)
+{
+	int i;
+
+	/* Filter out a few obvious non-matches first */
+	if (!pci_is_pcie(dev) || pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
+		return false;
+
+	for (i = 0; i < ARRAY_SIZE(pci_quirk_intel_pch_acs_ids); i++)
+		if (pci_quirk_intel_pch_acs_ids[i] == dev->device)
+			return true;
+
+	return false;
+}
+
+#define INTEL_PCH_ACS_FLAGS (PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_SV)
+
+static int pci_quirk_intel_pch_acs(struct pci_dev *dev, u16 acs_flags)
+{
+	u16 flags = dev->dev_flags & PCI_DEV_FLAGS_ACS_ENABLED_QUIRK ?
+		    INTEL_PCH_ACS_FLAGS : 0;
+
+	if (!pci_quirk_intel_pch_acs_match(dev))
+		return -ENOTTY;
+
+	return acs_flags & ~flags ? 0 : 1;
+}
+
 static const struct pci_dev_acs_enabled {
 	u16 vendor;
 	u16 device;
@@ -3434,6 +3489,7 @@ static const struct pci_dev_acs_enabled {
 	{ PCI_VENDOR_ID_ATI, 0x439d, pci_quirk_amd_sb_acs },
 	{ PCI_VENDOR_ID_ATI, 0x4384, pci_quirk_amd_sb_acs },
 	{ PCI_VENDOR_ID_ATI, 0x4399, pci_quirk_amd_sb_acs },
+	{ PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_quirk_intel_pch_acs },
 	{ 0 }
 };
 
@@ -3461,3 +3517,132 @@ int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags)
 
 	return -ENOTTY;
 }
+
+/* Config space offset of Root Complex Base Address register */
+#define INTEL_LPC_RCBA_REG 0xf0
+/* 31:14 RCBA address */
+#define INTEL_LPC_RCBA_MASK 0xffffc000
+/* RCBA Enable */
+#define INTEL_LPC_RCBA_ENABLE (1 << 0)
+
+/* Backbone Scratch Pad Register */
+#define INTEL_BSPR_REG 0x1104
+/* Backbone Peer Non-Posted Disable */
+#define INTEL_BSPR_REG_BPNPD (1 << 8)
+/* Backbone Peer Posted Disable */
+#define INTEL_BSPR_REG_BPPD  (1 << 9)
+
+/* Upstream Peer Decode Configuration Register */
+#define INTEL_UPDCR_REG 0x1114
+/* 5:0 Peer Decode Enable bits */
+#define INTEL_UPDCR_REG_MASK 0x3f
+
+static int pci_quirk_enable_intel_lpc_acs(struct pci_dev *dev)
+{
+	u32 rcba, bspr, updcr;
+	void __iomem *rcba_mem;
+
+	/*
+	 * Read the RCBA register from the LPC (D31:F0).  PCH root ports
+	 * are D28:F* and therefore get probed before LPC, thus we can't
+	 * use pci_get_slot/pci_read_config_dword here.
+	 */
+	pci_bus_read_config_dword(dev->bus, PCI_DEVFN(31, 0),
+				  INTEL_LPC_RCBA_REG, &rcba);
+	if (!(rcba & INTEL_LPC_RCBA_ENABLE))
+		return -EINVAL;
+
+	rcba_mem = ioremap_nocache(rcba & INTEL_LPC_RCBA_MASK,
+				   PAGE_ALIGN(INTEL_UPDCR_REG));
+	if (!rcba_mem)
+		return -ENOMEM;
+
+	/*
+	 * The BSPR can disallow peer cycles, but it's set by soft strap and
+	 * therefore read-only.  If both posted and non-posted peer cycles are
+	 * disallowed, we're ok.  If either are allowed, then we need to use
+	 * the UPDCR to disable peer decodes for each port.  This provides the
+	 * PCIe ACS equivalent of PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF
+	 */
+	bspr = readl(rcba_mem + INTEL_BSPR_REG);
+	bspr &= INTEL_BSPR_REG_BPNPD | INTEL_BSPR_REG_BPPD;
+	if (bspr != (INTEL_BSPR_REG_BPNPD | INTEL_BSPR_REG_BPPD)) {
+		updcr = readl(rcba_mem + INTEL_UPDCR_REG);
+		if (updcr & INTEL_UPDCR_REG_MASK) {
+			dev_info(&dev->dev, "Disabling UPDCR peer decodes\n");
+			updcr &= ~INTEL_UPDCR_REG_MASK;
+			writel(updcr, rcba_mem + INTEL_UPDCR_REG);
+		}
+	}
+
+	iounmap(rcba_mem);
+	return 0;
+}
+
+/* Miscellaneous Port Configuration register */
+#define INTEL_MPC_REG 0xd8
+/* MPC: Invalid Receive Bus Number Check Enable */
+#define INTEL_MPC_REG_IRBNCE (1 << 26)
+
+static void pci_quirk_enable_intel_rp_mpc_acs(struct pci_dev *dev)
+{
+	u32 mpc;
+
+	/*
+	 * When enabled, the IRBNCE bit of the MPC register enables the
+	 * equivalent of PCI ACS Source Validation (PCI_ACS_SV), which
+	 * ensures that requester IDs fall within the bus number range
+	 * of the bridge.  Enable if not already.
+	 */
+	pci_read_config_dword(dev, INTEL_MPC_REG, &mpc);
+	if (!(mpc & INTEL_MPC_REG_IRBNCE)) {
+		dev_info(&dev->dev, "Enabling MPC IRBNCE\n");
+		mpc |= INTEL_MPC_REG_IRBNCE;
+		pci_write_config_word(dev, INTEL_MPC_REG, mpc);
+	}
+}
+
+static int pci_quirk_enable_intel_pch_acs(struct pci_dev *dev)
+{
+	if (!pci_quirk_intel_pch_acs_match(dev))
+		return -ENOTTY;
+
+	if (pci_quirk_enable_intel_lpc_acs(dev)) {
+		dev_warn(&dev->dev, "Failed to enable Intel PCH ACS quirk\n");
+		return 0;
+	}
+
+	pci_quirk_enable_intel_rp_mpc_acs(dev);
+
+	dev->dev_flags |= PCI_DEV_FLAGS_ACS_ENABLED_QUIRK;
+
+	dev_info(&dev->dev, "Intel PCH root port ACS workaround enabled\n");
+
+	return 0;
+}
+
+static const struct pci_dev_enable_acs {
+	u16 vendor;
+	u16 device;
+	int (*enable_acs)(struct pci_dev *dev);
+} pci_dev_enable_acs[] = {
+	{ PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_quirk_enable_intel_pch_acs },
+	{ 0 }
+};
+
+void pci_dev_specific_enable_acs(struct pci_dev *dev)
+{
+	const struct pci_dev_enable_acs *i;
+	int ret;
+
+	for (i = pci_dev_enable_acs; i->enable_acs; i++) {
+		if ((i->vendor == dev->vendor ||
+		     i->vendor == (u16)PCI_ANY_ID) &&
+		    (i->device == dev->device ||
+		     i->device == (u16)PCI_ANY_ID)) {
+			ret = i->enable_acs(dev);
+			if (ret >= 0)
+				return;
+		}
+	}
+}

include/linux/pci.h

@@ -170,6 +170,8 @@ enum pci_dev_flags {
 	PCI_DEV_FLAGS_NO_D3 = (__force pci_dev_flags_t) 2,
 	/* Provide indication device is assigned by a Virtual Machine Manager */
 	PCI_DEV_FLAGS_ASSIGNED = (__force pci_dev_flags_t) 4,
+	/* Flag for quirk use to store if quirk-specific ACS is enabled */
+	PCI_DEV_FLAGS_ACS_ENABLED_QUIRK = (__force pci_dev_flags_t) 8,
 };
 
 enum pci_irq_reroute_variant {
@@ -1510,6 +1512,7 @@ enum pci_fixup_pass {
 void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev);
 struct pci_dev *pci_get_dma_source(struct pci_dev *dev);
 int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags);
+void pci_dev_specific_enable_acs(struct pci_dev *dev);
 #else
 static inline void pci_fixup_device(enum pci_fixup_pass pass,
 				    struct pci_dev *dev) { }
@@ -1522,6 +1525,7 @@ static inline int pci_dev_specific_acs_enabled(struct pci_dev *dev,
 {
 	return -ENOTTY;
 }
+static inline void pci_dev_specific_enable_acs(struct pci_dev *dev) { }
 #endif
 
 void __iomem *pcim_iomap(struct pci_dev *pdev, int bar, unsigned long maxlen);