[patch 2.5.33] pci bus resources, transparent bridges

From: Ivan Kokshaysky (ink@jurassic.park.msu.ru)
Date: Sun Sep 08 2002 - 09:58:55 EST


Added PCI_BUS_NUM_RESOURCES as Ben suggested. Default value is 4
and can be overridden by arch (probably in asm/system.h).
pci_read_bridge_bases() and pci_assign_bus_resource() changed
accordingly. "for (i = 0 ; i < 4; i++)" in pci_add_new_bus() not
changed, as it's used _only_ for pci-pci and cardbus bridges.

Ivan.

--- 2.5.33/arch/i386/pci/fixup.c Sun Sep 1 02:04:50 2002
+++ linux/arch/i386/pci/fixup.c Fri Sep 6 16:14:47 2002
@@ -166,6 +166,22 @@ static void __init pci_fixup_via_northbr
         }
 }
 
+/*
+ * For some reasons Intel decided that certain parts of their
+ * 815, 845 and some other chipsets must look like PCI-to-PCI bridges
+ * while they are obviously not. The 82801 family (AA, AB, BAM/CAM,
+ * BA/CA/DB and E) PCI bridges are actually HUB-to-PCI ones, according
+ * to Intel terminology. These devices do forward all addresses from
+ * system to PCI bus no matter what are their window settings, so they are
+ * "transparent" (or subtractive decoding) from programmers point of view.
+ */
+static void __init pci_fixup_transparent_bridge(struct pci_dev *dev)
+{
+ if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI &&
+ (dev->device & 0xff00) == 0x2400)
+ dev->transparent = 1;
+}
+
 struct pci_fixup pcibios_fixups[] = {
         { PCI_FIXUP_HEADER, PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82451NX, pci_fixup_i450nx },
         { PCI_FIXUP_HEADER, PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82454GX, pci_fixup_i450gx },
@@ -183,5 +199,6 @@ struct pci_fixup pcibios_fixups[] = {
         { PCI_FIXUP_HEADER, PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8361, pci_fixup_via_northbridge_bug },
         { PCI_FIXUP_HEADER, PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8367_0, pci_fixup_via_northbridge_bug },
         { PCI_FIXUP_HEADER, PCI_VENDOR_ID_NCR, PCI_DEVICE_ID_NCR_53C810, pci_fixup_ncr53c810 },
+ { PCI_FIXUP_HEADER, PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_fixup_transparent_bridge },
         { 0 }
 };
--- 2.5.33/include/linux/pci.h Sun Sep 1 02:05:03 2002
+++ linux/include/linux/pci.h Fri Sep 6 16:21:46 2002
@@ -386,6 +386,9 @@ struct pci_dev {
         int ro; /* ISAPnP: read only */
         unsigned short regs; /* ISAPnP: supported registers */
 
+ /* These fields are used by common fixups */
+ unsigned short transparent:1; /* Transparent PCI bridge */
+
         int (*prepare)(struct pci_dev *dev); /* ISAPnP hooks */
         int (*activate)(struct pci_dev *dev);
         int (*deactivate)(struct pci_dev *dev);
@@ -406,6 +409,10 @@ struct pci_dev {
 #define PCI_ROM_RESOURCE 6
 #define PCI_BRIDGE_RESOURCES 7
 #define PCI_NUM_RESOURCES 11
+
+#ifndef PCI_BUS_NUM_RESOURCES
+#define PCI_BUS_NUM_RESOURCES 4
+#endif
   
 #define PCI_REGION_FLAG_MASK 0x0fU /* These bits of resource flags tell us the PCI region flags */
 
@@ -415,7 +422,8 @@ struct pci_bus {
         struct list_head children; /* list of child buses */
         struct list_head devices; /* list of devices on this bus */
         struct pci_dev *self; /* bridge device as seen by parent */
- struct resource *resource[4]; /* address space routed to this bus */
+ struct resource *resource[PCI_BUS_NUM_RESOURCES];
+ /* address space routed to this bus */
 
         struct pci_ops *ops; /* configuration access functions */
         void *sysdata; /* hook for sys-specific extension */
--- 2.5.33/drivers/pci/quirks.c Sun Sep 1 02:04:47 2002
+++ linux/drivers/pci/quirks.c Fri Sep 6 16:14:47 2002
@@ -471,6 +471,11 @@ static void __init quirk_dunord ( struct
         r -> end = 0xffffff;
 }
 
+static void __init quirk_transparent_bridge(struct pci_dev *dev)
+{
+ dev->transparent = 1;
+}
+
 /*
  * The main table of quirks.
  */
@@ -525,6 +530,13 @@ static struct pci_fixup pci_fixups[] __i
 
         { PCI_FIXUP_FINAL, PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_VIPER_7410, quirk_amd_ioapic },
         { PCI_FIXUP_FINAL, PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_FE_GATE_700C, quirk_amd_ordering },
+ /*
+ * i82380FB mobile docking controller: its PCI-to-PCI bridge
+ * is subtractive decoding (transparent), and does indicate this
+ * in the ProgIf. Unfortunately, the ProgIf value is wrong - 0x80
+ * instead of 0x01.
+ */
+ { PCI_FIXUP_HEADER, PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82380FB, quirk_transparent_bridge },
 
         { 0 }
 };
--- 2.5.33/drivers/pci/probe.c Sun Sep 1 02:04:51 2002
+++ linux/drivers/pci/probe.c Fri Sep 6 16:14:47 2002
@@ -128,6 +128,13 @@ void __devinit pci_read_bridge_bases(str
         if (!dev) /* It's a host bus, nothing to read */
                 return;
 
+ if (dev->transparent) {
+ printk("Transparent bridge - %s\n", dev->name);
+ for(i = 0; i < PCI_BUS_NUM_RESOURCES; i++)
+ child->resource[i] = child->parent->resource[i];
+ return;
+ }
+
         for(i=0; i<3; i++)
                 child->resource[i] = &dev->resource[PCI_BRIDGE_RESOURCES+i];
 
@@ -149,13 +156,6 @@ void __devinit pci_read_bridge_bases(str
                 res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO;
                 res->start = base;
                 res->end = limit + 0xfff;
- } else {
- /*
- * Ugh. We don't know enough about this bridge. Just assume
- * that it's entirely transparent.
- */
- printk(KERN_ERR "Unknown bridge resource %d: assuming transparent\n", 0);
- child->resource[0] = child->parent->resource[0];
         }
 
         res = child->resource[1];
@@ -167,10 +167,6 @@ void __devinit pci_read_bridge_bases(str
                 res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM;
                 res->start = base;
                 res->end = limit + 0xfffff;
- } else {
- /* See comment above. Same thing */
- printk(KERN_ERR "Unknown bridge resource %d: assuming transparent\n", 1);
- child->resource[1] = child->parent->resource[1];
         }
 
         res = child->resource[2];
@@ -197,10 +193,6 @@ void __devinit pci_read_bridge_bases(str
                 res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM | IORESOURCE_PREFETCH;
                 res->start = base;
                 res->end = limit + 0xfffff;
- } else {
- /* See comments above */
- printk(KERN_ERR "Unknown bridge resource %d: assuming transparent\n", 2);
- child->resource[2] = child->parent->resource[2];
         }
 }
 
@@ -389,6 +381,10 @@ int pci_setup_device(struct pci_dev * de
         case PCI_HEADER_TYPE_BRIDGE: /* bridge header */
                 if (class != PCI_CLASS_BRIDGE_PCI)
                         goto bad;
+ /* The PCI-to-PCI bridge spec requires that subtractive
+ decoding (i.e. transparent) bridge must have programming
+ interface code of 0x01. */
+ dev->transparent = ((class & 0xff) == 1);
                 pci_read_bases(dev, 2, PCI_ROM_ADDRESS1);
                 break;
 
--- 2.5.33/drivers/pci/setup-res.c Sun Sep 1 02:05:32 2002
+++ linux/drivers/pci/setup-res.c Sun Sep 8 18:35:14 2002
@@ -73,7 +73,7 @@ static int pci_assign_bus_resource(const
         int i;
 
         type_mask |= IORESOURCE_IO | IORESOURCE_MEM;
- for (i = 0 ; i < 4; i++) {
+ for (i = 0 ; i < PCI_BUS_NUM_RESOURCES; i++) {
                 struct resource *r = bus->resource[i];
                 if (!r)
                         continue;
-
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