5 files changed, 138 insertions, 16 deletions

diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index 73aef51a28f0..8fb16188cd82 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -228,6 +228,49 @@ int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 }
 EXPORT_SYMBOL(pci_bus_alloc_resource);
 
+/*
+ * The @idx resource of @dev should be a PCI-PCI bridge window.  If this
+ * resource fits inside a window of an upstream bridge, do nothing.  If it
+ * overlaps an upstream window but extends outside it, clip the resource so
+ * it fits completely inside.
+ */
+bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
+{
+        struct pci_bus *bus = dev->bus;
+        struct resource *res = &dev->resource[idx];
+        struct resource orig_res = *res;
+        struct resource *r;
+        int i;
+
+        pci_bus_for_each_resource(bus, r, i) {
+                resource_size_t start, end;
+
+                if (!r)
+                        continue;
+
+                if (resource_type(res) != resource_type(r))
+                        continue;
+
+                start = max(r->start, res->start);
+                end = min(r->end, res->end);
+
+                if (start > end)
+                        continue;       /* no overlap */
+
+                if (res->start == start && res->end == end)
+                        return false;   /* no change */
+
+                res->start = start;
+                res->end = end;
+                dev_printk(KERN_DEBUG, &dev->dev, "%pR clipped to %pR\n",
+                                 &orig_res, res);
+
+                return true;
+        }
+
+        return false;
+}
+
 void __weak pcibios_resource_survey_bus(struct pci_bus *bus) { }
 
 /**
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index cab05f31223f..e9d4fd861ba1 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3271,7 +3271,8 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
 {
         struct pci_dev *pdev;
 
-        if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self)
+        if (pci_is_root_bus(dev->bus) || dev->subordinate ||
+            !dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
                 return -ENOTTY;
 
         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
@@ -3305,7 +3306,8 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
 {
         struct pci_dev *pdev;
 
-        if (dev->subordinate || !dev->slot)
+        if (dev->subordinate || !dev->slot ||
+            dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
                 return -ENOTTY;
 
         list_for_each_entry(pdev, &dev->bus->devices, bus_list)
@@ -3557,6 +3559,20 @@ int pci_try_reset_function(struct pci_dev *dev)
 }
 EXPORT_SYMBOL_GPL(pci_try_reset_function);
 
+/* Do any devices on or below this bus prevent a bus reset? */
+static bool pci_bus_resetable(struct pci_bus *bus)
+{
+        struct pci_dev *dev;
+
+        list_for_each_entry(dev, &bus->devices, bus_list) {
+                if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
+                    (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
+                        return false;
+        }
+
+        return true;
+}
+
 /* Lock devices from the top of the tree down */
 static void pci_bus_lock(struct pci_bus *bus)
 {
@@ -3607,6 +3623,22 @@ unlock:
         return 0;
 }
 
+/* Do any devices on or below this slot prevent a bus reset? */
+static bool pci_slot_resetable(struct pci_slot *slot)
+{
+        struct pci_dev *dev;
+
+        list_for_each_entry(dev, &slot->bus->devices, bus_list) {
+                if (!dev->slot || dev->slot != slot)
+                        continue;
+                if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET ||
+                    (dev->subordinate && !pci_bus_resetable(dev->subordinate)))
+                        return false;
+        }
+
+        return true;
+}
+
 /* Lock devices from the top of the tree down */
 static void pci_slot_lock(struct pci_slot *slot)
 {
@@ -3728,7 +3760,7 @@ static int pci_slot_reset(struct pci_slot *slot, int probe)
 {
         int rc;
 
-        if (!slot)
+        if (!slot || !pci_slot_resetable(slot))
                 return -ENOTTY;
 
         if (!probe)
@@ -3820,7 +3852,7 @@ EXPORT_SYMBOL_GPL(pci_try_reset_slot);
 
 static int pci_bus_reset(struct pci_bus *bus, int probe)
 {
-        if (!bus->self)
+        if (!bus->self || !pci_bus_resetable(bus))
                 return -ENOTTY;
 
         if (probe)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 8aff29a804ff..d54632a1db43 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -208,6 +208,7 @@ void __pci_bus_size_bridges(struct pci_bus *bus,
 void __pci_bus_assign_resources(const struct pci_bus *bus,
                                 struct list_head *realloc_head,
                                 struct list_head *fail_head);
+bool pci_bus_clip_resource(struct pci_dev *dev, int idx);
 
 /**
  * pci_ari_enabled - query ARI forwarding status
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index ed6f89b6efe5..e52356aa09b8 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3028,6 +3028,20 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_REALTEK, 0x8169,
 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_MELLANOX, PCI_ANY_ID,
                          quirk_broken_intx_masking);
 
+static void quirk_no_bus_reset(struct pci_dev *dev)
+{
+        dev->dev_flags |= PCI_DEV_FLAGS_NO_BUS_RESET;
+}
+
+/*
+ * Atheros AR93xx chips do not behave after a bus reset.  The device will
+ * throw a Link Down error on AER-capable systems and regardless of AER,
+ * config space of the device is never accessible again and typically
+ * causes the system to hang or reset when access is attempted.
+ * http://www.spinics.net/lists/linux-pci/msg34797.html
+ */
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0030, quirk_no_bus_reset);
+
 #ifdef CONFIG_ACPI
 /*
  * Apple: Shutdown Cactus Ridge Thunderbolt controller.
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 0482235eee92..e3e17f3c0f0f 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -530,9 +530,8 @@ EXPORT_SYMBOL(pci_setup_cardbus);
    config space writes, so it's quite possible that an I/O window of
    the bridge will have some undesirable address (e.g. 0) after the
    first write. Ditto 64-bit prefetchable MMIO.  */
-static void pci_setup_bridge_io(struct pci_bus *bus)
+static void pci_setup_bridge_io(struct pci_dev *bridge)
 {
-        struct pci_dev *bridge = bus->self;
         struct resource *res;
         struct pci_bus_region region;
         unsigned long io_mask;
@@ -545,7 +544,7 @@ static void pci_setup_bridge_io(struct pci_bus *bus)
                 io_mask = PCI_IO_1K_RANGE_MASK;
 
         /* Set up the top and bottom of the PCI I/O segment for this bus. */
-        res = bus->resource[0];
+        res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0];
         pcibios_resource_to_bus(bridge->bus, &region, res);
         if (res->flags & IORESOURCE_IO) {
                 pci_read_config_word(bridge, PCI_IO_BASE, &l);
@@ -568,15 +567,14 @@ static void pci_setup_bridge_io(struct pci_bus *bus)
         pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, io_upper16);
 }
 
-static void pci_setup_bridge_mmio(struct pci_bus *bus)
+static void pci_setup_bridge_mmio(struct pci_dev *bridge)
 {
-        struct pci_dev *bridge = bus->self;
         struct resource *res;
         struct pci_bus_region region;
         u32 l;
 
         /* Set up the top and bottom of the PCI Memory segment for this bus. */
-        res = bus->resource[1];
+        res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1];
         pcibios_resource_to_bus(bridge->bus, &region, res);
         if (res->flags & IORESOURCE_MEM) {
                 l = (region.start >> 16) & 0xfff0;
@@ -588,9 +586,8 @@ static void pci_setup_bridge_mmio(struct pci_bus *bus)
         pci_write_config_dword(bridge, PCI_MEMORY_BASE, l);
 }
 
-static void pci_setup_bridge_mmio_pref(struct pci_bus *bus)
+static void pci_setup_bridge_mmio_pref(struct pci_dev *bridge)
 {
-        struct pci_dev *bridge = bus->self;
         struct resource *res;
         struct pci_bus_region region;
         u32 l, bu, lu;
@@ -602,7 +599,7 @@ static void pci_setup_bridge_mmio_pref(struct pci_bus *bus)
 
         /* Set up PREF base/limit. */
         bu = lu = 0;
-        res = bus->resource[2];
+        res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2];
         pcibios_resource_to_bus(bridge->bus, &region, res);
         if (res->flags & IORESOURCE_PREFETCH) {
                 l = (region.start >> 16) & 0xfff0;
@@ -630,13 +627,13 @@ static void __pci_setup_bridge(struct pci_bus *bus, unsigned long type)
                  &bus->busn_res);
 
         if (type & IORESOURCE_IO)
-                pci_setup_bridge_io(bus);
+                pci_setup_bridge_io(bridge);
 
         if (type & IORESOURCE_MEM)
-                pci_setup_bridge_mmio(bus);
+                pci_setup_bridge_mmio(bridge);
 
         if (type & IORESOURCE_PREFETCH)
-                pci_setup_bridge_mmio_pref(bus);
+                pci_setup_bridge_mmio_pref(bridge);
 
         pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
 }
@@ -649,6 +646,41 @@ void pci_setup_bridge(struct pci_bus *bus)
         __pci_setup_bridge(bus, type);
 }
 
+
+int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
+{
+        if (i < PCI_BRIDGE_RESOURCES || i > PCI_BRIDGE_RESOURCE_END)
+                return 0;
+
+        if (pci_claim_resource(bridge, i) == 0)
+                return 0;       /* claimed the window */
+
+        if ((bridge->class >> 8) != PCI_CLASS_BRIDGE_PCI)
+                return 0;
+
+        if (!pci_bus_clip_resource(bridge, i))
+                return -EINVAL; /* clipping didn't change anything */
+
+        switch (i - PCI_BRIDGE_RESOURCES) {
+        case 0:
+                pci_setup_bridge_io(bridge);
+                break;
+        case 1:
+                pci_setup_bridge_mmio(bridge);
+                break;
+        case 2:
+                pci_setup_bridge_mmio_pref(bridge);
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        if (pci_claim_resource(bridge, i) == 0)
+                return 0;       /* claimed a smaller window */
+
+        return -EINVAL;
+}
+
 /* Check whether the bridge supports optional I/O and
    prefetchable memory ranges. If not, the respective
    base/limit registers must be read-only and read as 0. */