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-rw-r--r--arch/powerpc/kernel/pci-common.c163
1 files changed, 116 insertions, 47 deletions
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 8c0270929cc..01ce8c38bae 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -780,11 +780,6 @@ static void __devinit fixup_resource(struct resource *res, struct pci_dev *dev)
res->start = (res->start + offset) & mask;
res->end = (res->end + offset) & mask;
-
- pr_debug("PCI:%s %016llx-%016llx\n",
- pci_name(dev),
- (unsigned long long)res->start,
- (unsigned long long)res->end);
}
@@ -830,6 +825,11 @@ static void __devinit pcibios_fixup_resources(struct pci_dev *dev)
(unsigned int)res->flags);
fixup_resource(res, dev);
+
+ pr_debug("PCI:%s %016llx-%016llx\n",
+ pci_name(dev),
+ (unsigned long long)res->start,
+ (unsigned long long)res->end);
}
/* Call machine specific resource fixup */
@@ -838,58 +838,127 @@ static void __devinit pcibios_fixup_resources(struct pci_dev *dev)
}
DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pcibios_fixup_resources);
-static void __devinit __pcibios_fixup_bus(struct pci_bus *bus)
+/* This function tries to figure out if a bridge resource has been initialized
+ * by the firmware or not. It doesn't have to be absolutely bullet proof, but
+ * things go more smoothly when it gets it right. It should covers cases such
+ * as Apple "closed" bridge resources and bare-metal pSeries unassigned bridges
+ */
+static int __devinit pcibios_uninitialized_bridge_resource(struct pci_bus *bus,
+ struct resource *res)
{
struct pci_controller *hose = pci_bus_to_host(bus);
struct pci_dev *dev = bus->self;
+ resource_size_t offset;
+ u16 command;
+ int i;
- pr_debug("PCI: Fixup bus %d (%s)\n", bus->number, dev ? pci_name(dev) : "PHB");
+ /* We don't do anything if PCI_PROBE_ONLY is set */
+ if (ppc_pci_flags & PPC_PCI_PROBE_ONLY)
+ return 0;
- /* Fixup PCI<->PCI bridges. Host bridges are handled separately, for
- * now differently between 32 and 64 bits.
- */
- if (dev != NULL) {
- struct resource *res;
- int i;
+ /* Job is a bit different between memory and IO */
+ if (res->flags & IORESOURCE_MEM) {
+ /* If the BAR is non-0 (res != pci_mem_offset) then it's probably been
+ * initialized by somebody
+ */
+ if (res->start != hose->pci_mem_offset)
+ return 0;
- for (i = 0; i < PCI_BUS_NUM_RESOURCES; ++i) {
- if ((res = bus->resource[i]) == NULL)
- continue;
- if (!res->flags)
- continue;
- if (i >= 3 && bus->self->transparent)
- continue;
- /* On PowerMac, Apple leaves bridge windows open over
- * an inaccessible region of memory space (0...fffff)
- * which is somewhat bogus, but that's what they think
- * means disabled...
- *
- * We clear those to force them to be reallocated later
- *
- * We detect such regions by the fact that the base is
- * equal to the pci_mem_offset of the host bridge and
- * their size is smaller than 1M.
- */
- if (res->flags & IORESOURCE_MEM &&
- res->start == hose->pci_mem_offset &&
- res->end < 0x100000) {
- printk(KERN_INFO
- "PCI: Closing bogus Apple Firmware"
- " region %d on bus 0x%02x\n",
- i, bus->number);
- res->flags = 0;
- continue;
- }
+ /* The BAR is 0, let's check if memory decoding is enabled on
+ * the bridge. If not, we consider it unassigned
+ */
+ pci_read_config_word(dev, PCI_COMMAND, &command);
+ if ((command & PCI_COMMAND_MEMORY) == 0)
+ return 1;
- pr_debug("PCI:%s Bus rsrc %d %016llx-%016llx [%x] fixup...\n",
- pci_name(dev), i,
- (unsigned long long)res->start,\
- (unsigned long long)res->end,
- (unsigned int)res->flags);
+ /* Memory decoding is enabled and the BAR is 0. If any of the bridge
+ * resources covers that starting address (0 then it's good enough for
+ * us for memory
+ */
+ for (i = 0; i < 3; i++) {
+ if ((hose->mem_resources[i].flags & IORESOURCE_MEM) &&
+ hose->mem_resources[i].start == hose->pci_mem_offset)
+ return 0;
+ }
+
+ /* Well, it starts at 0 and we know it will collide so we may as
+ * well consider it as unassigned. That covers the Apple case.
+ */
+ return 1;
+ } else {
+ /* If the BAR is non-0, then we consider it assigned */
+ offset = (unsigned long)hose->io_base_virt - _IO_BASE;
+ if (((res->start - offset) & 0xfffffffful) != 0)
+ return 0;
+
+ /* Here, we are a bit different than memory as typically IO space
+ * starting at low addresses -is- valid. What we do instead if that
+ * we consider as unassigned anything that doesn't have IO enabled
+ * in the PCI command register, and that's it.
+ */
+ pci_read_config_word(dev, PCI_COMMAND, &command);
+ if (command & PCI_COMMAND_IO)
+ return 0;
+
+ /* It's starting at 0 and IO is disabled in the bridge, consider
+ * it unassigned
+ */
+ return 1;
+ }
+}
+
+/* Fixup resources of a PCI<->PCI bridge */
+static void __devinit pcibios_fixup_bridge(struct pci_bus *bus)
+{
+ struct resource *res;
+ int i;
+
+ struct pci_dev *dev = bus->self;
- fixup_resource(res, dev);
+ for (i = 0; i < PCI_BUS_NUM_RESOURCES; ++i) {
+ if ((res = bus->resource[i]) == NULL)
+ continue;
+ if (!res->flags)
+ continue;
+ if (i >= 3 && bus->self->transparent)
+ continue;
+
+ pr_debug("PCI:%s Bus rsrc %d %016llx-%016llx [%x] fixup...\n",
+ pci_name(dev), i,
+ (unsigned long long)res->start,\
+ (unsigned long long)res->end,
+ (unsigned int)res->flags);
+
+ /* Perform fixup */
+ fixup_resource(res, dev);
+
+ /* Try to detect uninitialized P2P bridge resources,
+ * and clear them out so they get re-assigned later
+ */
+ if (pcibios_uninitialized_bridge_resource(bus, res)) {
+ res->flags = 0;
+ pr_debug("PCI:%s (unassigned)\n", pci_name(dev));
+ } else {
+
+ pr_debug("PCI:%s %016llx-%016llx\n",
+ pci_name(dev),
+ (unsigned long long)res->start,
+ (unsigned long long)res->end);
}
}
+}
+
+static void __devinit __pcibios_fixup_bus(struct pci_bus *bus)
+{
+ struct pci_dev *dev = bus->self;
+
+ pr_debug("PCI: Fixup bus %d (%s)\n", bus->number, dev ? pci_name(dev) : "PHB");
+
+ /* Fixup PCI<->PCI bridges. Host bridges are handled separately, for
+ * now differently between 32 and 64 bits.
+ */
+ if (dev != NULL)
+ pcibios_fixup_bridge(bus);
/* Additional setup that is different between 32 and 64 bits for now */
pcibios_do_bus_setup(bus);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-29 12:00:42 +0000