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authorBjorn Helgaas <bjorn.helgaas@hp.com>2010-04-27 14:45:43 -0600
committerJesse Barnes <jbarnes@virtuousgeek.org>2010-04-28 09:17:45 -0700
commit48728e077480910df45baabc5f87b04276348c90 (patch)
tree8a8114da4840e84ba60050b953123168aefc2dcf
parent55051feb57eba600b366006757304a0af3ada2bd (diff)
downloadlinux-linaro-48728e077480910df45baabc5f87b04276348c90.tar.gz
x86/PCI: compute Address Space length rather than using _LEN
ACPI _CRS Address Space Descriptors have _MIN, _MAX, and _LEN. Linux has been computing Address Spaces as [_MIN to _MIN + _LEN - 1]. Based on the tests in the bug reports below, Windows apparently uses [_MIN to _MAX]. Per spec (ACPI 4.0, Table 6-40), for _CRS fixed-size, fixed location descriptors, "_LEN must be (_MAX - _MIN + 1)", and when that's true, it doesn't matter which way we compute the end. But of course, there are BIOSes that don't follow this rule, and we're better off if Linux handles those exceptions the same way as Windows. This patch makes Linux use [_MIN to _MAX], as Windows seems to do. This effectively reverts d558b483d5 and 03db42adfe and replaces them with simpler code. https://bugzilla.kernel.org/show_bug.cgi?id=14337 (round) https://bugzilla.kernel.org/show_bug.cgi?id=15480 (truncate) Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
-rw-r--r--arch/x86/pci/acpi.c40
1 files changed, 2 insertions, 38 deletions
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 44f83ce0247..31930fd30ea 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -121,30 +121,6 @@ count_resource(struct acpi_resource *acpi_res, void *data)
return AE_OK;
}
-static void
-align_resource(struct acpi_device *bridge, struct resource *res)
-{
- int align = (res->flags & IORESOURCE_MEM) ? 16 : 4;
-
- /*
- * Host bridge windows are not BARs, but the decoders on the PCI side
- * that claim this address space have starting alignment and length
- * constraints, so fix any obvious BIOS goofs.
- */
- if (!IS_ALIGNED(res->start, align)) {
- dev_printk(KERN_DEBUG, &bridge->dev,
- "host bridge window %pR invalid; "
- "aligning start to %d-byte boundary\n", res, align);
- res->start &= ~(align - 1);
- }
- if (!IS_ALIGNED(res->end + 1, align)) {
- dev_printk(KERN_DEBUG, &bridge->dev,
- "host bridge window %pR invalid; "
- "aligning end to %d-byte boundary\n", res, align);
- res->end = ALIGN(res->end, align) - 1;
- }
-}
-
static acpi_status
setup_resource(struct acpi_resource *acpi_res, void *data)
{
@@ -154,7 +130,7 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
acpi_status status;
unsigned long flags;
struct resource *root, *conflict;
- u64 start, end, max_len;
+ u64 start, end;
status = resource_to_addr(acpi_res, &addr);
if (!ACPI_SUCCESS(status))
@@ -171,19 +147,8 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
} else
return AE_OK;
- max_len = addr.maximum - addr.minimum + 1;
- if (addr.address_length > max_len) {
- dev_printk(KERN_DEBUG, &info->bridge->dev,
- "host bridge window length %#llx doesn't fit in "
- "%#llx-%#llx, trimming\n",
- (unsigned long long) addr.address_length,
- (unsigned long long) addr.minimum,
- (unsigned long long) addr.maximum);
- addr.address_length = max_len;
- }
-
start = addr.minimum + addr.translation_offset;
- end = start + addr.address_length - 1;
+ end = addr.maximum + addr.translation_offset;
res = &info->res[info->res_num];
res->name = info->name;
@@ -191,7 +156,6 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
res->start = start;
res->end = end;
res->child = NULL;
- align_resource(info->bridge, res);
if (!pci_use_crs) {
dev_printk(KERN_DEBUG, &info->bridge->dev,