diff options
| author | Aaron Durbin <adurbin@chromium.org> | 2014-02-08 15:41:52 -0600 |
|---|---|---|
| committer | Aaron Durbin <adurbin@google.com> | 2014-02-09 22:08:53 +0100 |
| commit | ca4f4b8c9eef77fbcad0af3b21885a337a1f2c83 (patch) | |
| tree | d6d185b7a25c9a1f8c0e6105f34178cb0658ba71 /src/cpu/x86 | |
| parent | 892728c65fcd82cab43e334396b86fc257ecf256 (diff) | |
mtrr: only add prefetchable resources as WRCOMB for VGA devices
Be more conservative and only add VGA devices' prefetchable
resources as write-combining in the address space. Previously
all prefetchable memory was added as a write-combining memory
type. Some hardware incorrectly advertises its BAR as
prefetchable when it shouldn't be.
A new memranges_add_resources_filter() function is added
to provide additional filtering on device and resource.
Change-Id: I3fc55b90d8c5b694c5aa9e2f34db1b4ef845ce10
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/5169
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
Tested-by: build bot (Jenkins)
Diffstat (limited to 'src/cpu/x86')
| -rw-r--r-- | src/cpu/x86/mtrr/mtrr.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/src/cpu/x86/mtrr/mtrr.c b/src/cpu/x86/mtrr/mtrr.c index dfb9c94eeb..d85a86982c 100644 --- a/src/cpu/x86/mtrr/mtrr.c +++ b/src/cpu/x86/mtrr/mtrr.c @@ -30,6 +30,7 @@ #include <bootstate.h> #include <console/console.h> #include <device/device.h> +#include <device/pci_ids.h> #include <cpu/cpu.h> #include <cpu/x86/msr.h> #include <cpu/x86/mtrr.h> @@ -154,6 +155,20 @@ static inline int range_entry_mtrr_type(struct range_entry *r) return range_entry_tag(r) & MTRR_TAG_MASK; } +static int filter_vga_wrcomb(struct device *dev, struct resource *res) +{ + /* Only handle PCI devices. */ + if (dev->path.type != DEVICE_PATH_PCI) + return 0; + + /* Only handle VGA class devices. */ + if (((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)) + return 0; + + /* Add resource as write-combining in the address space. */ + return 1; +} + static struct memranges *get_physical_address_space(void) { static struct memranges *addr_space; @@ -181,8 +196,8 @@ static struct memranges *get_physical_address_space(void) * resources are appropriate for this MTRR type. */ match = IORESOURCE_PREFETCH; mask |= match; - memranges_add_resources(addr_space, mask, match, - MTRR_TYPE_WRCOMB); + memranges_add_resources_filter(addr_space, mask, match, MTRR_TYPE_WRCOMB, + filter_vga_wrcomb); #if CONFIG_CACHE_ROM /* Add a write-protect region covering the ROM size |