Merge branch 'topic/alex-vfio-prep' into next

* topic/alex-vfio-prep:
  PCI: misc pci_reg additions
  PCI: create common pcibios_err_to_errno
  PCI: export pci_user functions for use by other drivers
  PCI: add ACS validation utility
  PCI: add PCI DMA source ID quirk

5 files changed, 160 insertions, 12 deletions

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 2a581642c237..ba91a7e17519 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -162,7 +162,8 @@ int pci_user_read_config_##size						\
         if (ret > 0)                                                    \
                 ret = -EINVAL;                                          \
         return ret;                                                     \
-}
+}                                                                       \
+EXPORT_SYMBOL_GPL(pci_user_read_config_##size);
 
 /* Returns 0 on success, negative values indicate error. */
 #define PCI_USER_WRITE_CONFIG(size,type)                                \
@@ -181,7 +182,8 @@ int pci_user_write_config_##size					\
         if (ret > 0)                                                    \
                 ret = -EINVAL;                                          \
         return ret;                                                     \
-}
+}                                                                       \
+EXPORT_SYMBOL_GPL(pci_user_write_config_##size);
 
 PCI_USER_READ_CONFIG(byte, u8)
 PCI_USER_READ_CONFIG(word, u16)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index a23b071798f6..b743a9afb4dd 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2293,6 +2293,75 @@ void pci_enable_acs(struct pci_dev *dev)
 }
 
 /**
+ * pci_acs_enabled - test ACS against required flags for a given device
+ * @pdev: device to test
+ * @acs_flags: required PCI ACS flags
+ *
+ * Return true if the device supports the provided flags.  Automatically
+ * filters out flags that are not implemented on multifunction devices.
+ */
+bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags)
+{
+        int pos, ret;
+        u16 ctrl;
+
+        ret = pci_dev_specific_acs_enabled(pdev, acs_flags);
+        if (ret >= 0)
+                return ret > 0;
+
+        if (!pci_is_pcie(pdev))
+                return false;
+
+        /* Filter out flags not applicable to multifunction */
+        if (pdev->multifunction)
+                acs_flags &= (PCI_ACS_RR | PCI_ACS_CR |
+                              PCI_ACS_EC | PCI_ACS_DT);
+
+        if (pdev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM ||
+            pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
+            pdev->multifunction) {
+                pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ACS);
+                if (!pos)
+                        return false;
+
+                pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl);
+                if ((ctrl & acs_flags) != acs_flags)
+                        return false;
+        }
+
+        return true;
+}
+
+/**
+ * pci_acs_path_enable - test ACS flags from start to end in a hierarchy
+ * @start: starting downstream device
+ * @end: ending upstream device or NULL to search to the root bus
+ * @acs_flags: required flags
+ *
+ * Walk up a device tree from start to end testing PCI ACS support.  If
+ * any step along the way does not support the required flags, return false.
+ */
+bool pci_acs_path_enabled(struct pci_dev *start,
+                          struct pci_dev *end, u16 acs_flags)
+{
+        struct pci_dev *pdev, *parent = start;
+
+        do {
+                pdev = parent;
+
+                if (!pci_acs_enabled(pdev, acs_flags))
+                        return false;
+
+                if (pci_is_root_bus(pdev->bus))
+                        return (end == NULL);
+
+                parent = pdev->bus->self;
+        } while (pdev != end);
+
+        return true;
+}
+
+/**
  * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
  * @dev: the PCI device
  * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTD, 4=INTD)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 1c56ea8110b1..4884d77d33b6 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -86,13 +86,6 @@ static inline bool pci_is_bridge(struct pci_dev *pci_dev)
         return !!(pci_dev->subordinate);
 }
 
-extern int pci_user_read_config_byte(struct pci_dev *dev, int where, u8 *val);
-extern int pci_user_read_config_word(struct pci_dev *dev, int where, u16 *val);
-extern int pci_user_read_config_dword(struct pci_dev *dev, int where, u32 *val);
-extern int pci_user_write_config_byte(struct pci_dev *dev, int where, u8 val);
-extern int pci_user_write_config_word(struct pci_dev *dev, int where, u16 val);
-extern int pci_user_write_config_dword(struct pci_dev *dev, int where, u32 val);
-
 struct pci_vpd_ops {
         ssize_t (*read)(struct pci_dev *dev, loff_t pos, size_t count, void *buf);
         ssize_t (*write)(struct pci_dev *dev, loff_t pos, size_t count, const void *buf);
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 2a7521677541..27e2c8f4ec73 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3179,3 +3179,87 @@ int pci_dev_specific_reset(struct pci_dev *dev, int probe)
 
         return -ENOTTY;
 }
+
+static struct pci_dev *pci_func_0_dma_source(struct pci_dev *dev)
+{
+        if (!PCI_FUNC(dev->devfn))
+                return pci_dev_get(dev);
+
+        return pci_get_slot(dev->bus, PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
+}
+
+static const struct pci_dev_dma_source {
+        u16 vendor;
+        u16 device;
+        struct pci_dev *(*dma_source)(struct pci_dev *dev);
+} pci_dev_dma_source[] = {
+        /*
+         * https://bugzilla.redhat.com/show_bug.cgi?id=605888
+         *
+         * Some Ricoh devices use the function 0 source ID for DMA on
+         * other functions of a multifunction device.  The DMA devices
+         * is therefore function 0, which will have implications of the
+         * iommu grouping of these devices.
+         */
+        { PCI_VENDOR_ID_RICOH, 0xe822, pci_func_0_dma_source },
+        { PCI_VENDOR_ID_RICOH, 0xe230, pci_func_0_dma_source },
+        { PCI_VENDOR_ID_RICOH, 0xe832, pci_func_0_dma_source },
+        { PCI_VENDOR_ID_RICOH, 0xe476, pci_func_0_dma_source },
+        { 0 }
+};
+
+/*
+ * IOMMUs with isolation capabilities need to be programmed with the
+ * correct source ID of a device.  In most cases, the source ID matches
+ * the device doing the DMA, but sometimes hardware is broken and will
+ * tag the DMA as being sourced from a different device.  This function
+ * allows that translation.  Note that the reference count of the
+ * returned device is incremented on all paths.
+ */
+struct pci_dev *pci_get_dma_source(struct pci_dev *dev)
+{
+        const struct pci_dev_dma_source *i;
+
+        for (i = pci_dev_dma_source; i->dma_source; i++) {
+                if ((i->vendor == dev->vendor ||
+                     i->vendor == (u16)PCI_ANY_ID) &&
+                    (i->device == dev->device ||
+                     i->device == (u16)PCI_ANY_ID))
+                        return i->dma_source(dev);
+        }
+
+        return pci_dev_get(dev);
+}
+
+static const struct pci_dev_acs_enabled {
+        u16 vendor;
+        u16 device;
+        int (*acs_enabled)(struct pci_dev *dev, u16 acs_flags);
+} pci_dev_acs_enabled[] = {
+        { 0 }
+};
+
+int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags)
+{
+        const struct pci_dev_acs_enabled *i;
+        int ret;
+
+        /*
+         * Allow devices that do not expose standard PCIe ACS capabilities
+         * or control to indicate their support here.  Multi-function express
+         * devices which do not allow internal peer-to-peer between functions,
+         * but do not implement PCIe ACS may wish to return true here.
+         */
+        for (i = pci_dev_acs_enabled; i->acs_enabled; i++) {
+                if ((i->vendor == dev->vendor ||
+                     i->vendor == (u16)PCI_ANY_ID) &&
+                    (i->device == dev->device ||
+                     i->device == (u16)PCI_ANY_ID)) {
+                        ret = i->acs_enabled(dev, acs_flags);
+                        if (ret >= 0)
+                                return ret;
+                }
+        }
+
+        return -ENOTTY;
+}
diff --git a/drivers/xen/xen-pciback/conf_space.c b/drivers/xen/xen-pciback/conf_space.c
index 30d7be026c18..46ae0f9f02ad 100644
--- a/drivers/xen/xen-pciback/conf_space.c
+++ b/drivers/xen/xen-pciback/conf_space.c
@@ -124,7 +124,7 @@ static inline u32 merge_value(u32 val, u32 new_val, u32 new_val_mask,
         return val;
 }
 
-static int pcibios_err_to_errno(int err)
+static int xen_pcibios_err_to_errno(int err)
 {
         switch (err) {
         case PCIBIOS_SUCCESSFUL:
@@ -202,7 +202,7 @@ out:
                        pci_name(dev), size, offset, value);
 
         *ret_val = value;
-        return pcibios_err_to_errno(err);
+        return xen_pcibios_err_to_errno(err);
 }
 
 int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value)
@@ -290,7 +290,7 @@ int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value)
                 }
         }
 
-        return pcibios_err_to_errno(err);
+        return xen_pcibios_err_to_errno(err);
 }
 
 void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev)