[PATCH] pci: fix bridge 64bit flag setting

From: Yinghai Lu
Date: Tue Dec 01 2009 - 02:05:11 EST



Alex found one system that one pci bridge pref mmio 64 is not set correctly.
aka, the upper32 base/limit is not cleaned.
he found that bridge is supporting 64 bit pref mmio, but device under that
does not support that. so that IORESOURCE_MEM_64 get cleared in pbus_size_mem()

the fix will be:
make pci_bridge_check_ranges() to store the PCI_PREF_RANGE_TYPE_64 in addition
to IORESOURCE_MEM_64. just like pci_read_bridge_bases()
and later will use that bit in pci_setup_bridge_mmio_pref instead of
IORESOURCE_MEM_64.
also avoid touching upper32 regs if the bridge does not support 64bit pref.

Reported-by: Alex Williamson <alex.williamson@xxxxxx>
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>

---
drivers/pci/setup-bus.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

Index: linux-2.6/drivers/pci/setup-bus.c
===================================================================
--- linux-2.6.orig/drivers/pci/setup-bus.c
+++ linux-2.6/drivers/pci/setup-bus.c
@@ -289,7 +289,6 @@ static void pci_setup_bridge_mmio_pref(s
struct resource *res;
struct pci_bus_region region;
u32 l, bu, lu;
- int pref_mem64;

/* Clear out the upper 32 bits of PREF limit.
If PCI_PREF_BASE_UPPER32 was non-zero, this temporarily
@@ -297,7 +296,6 @@ static void pci_setup_bridge_mmio_pref(s
pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0);

/* Set up PREF base/limit. */
- pref_mem64 = 0;
bu = lu = 0;
res = bus->resource[2];
pcibios_resource_to_bus(bridge, &region, res);
@@ -305,7 +303,6 @@ static void pci_setup_bridge_mmio_pref(s
l = (region.start >> 16) & 0xfff0;
l |= region.end & 0xfff00000;
if (res->flags & IORESOURCE_MEM_64) {
- pref_mem64 = 1;
bu = upper_32_bits(region.start);
lu = upper_32_bits(region.end);
}
@@ -317,7 +314,7 @@ static void pci_setup_bridge_mmio_pref(s
}
pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);

- if (pref_mem64) {
+ if (res->flags & PCI_PREF_RANGE_TYPE_64) {
/* Set the upper 32 bits of PREF base & limit. */
pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu);
pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu);
@@ -385,8 +382,10 @@ static void pci_bridge_check_ranges(stru
}
if (pmem) {
b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
- if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64)
+ if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {
b_res[2].flags |= IORESOURCE_MEM_64;
+ b_res[2].flags |= PCI_PREF_RANGE_TYPE_64;
+ }
}

/* double check if bridge does support 64 bit pref */
--
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