haswell: add option to mark graphics memory write-combining.

The graphics memory can be accessed in a faster manner by
setting it to write-combing mode. Add an option to enable
write-combining for the graphics memory.

Change-Id: I797fcd9f0dfb074f9e45476773acbfe614eb4b0a
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2893
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
This commit is contained in:
Aaron Durbin 2013-03-22 22:23:05 -05:00 committed by Stefan Reinauer
parent 77a5b4046a
commit fcfe67c3b2
2 changed files with 26 additions and 1 deletions

View File

@ -82,6 +82,14 @@ config DCACHE_RAM_ROMSTAGE_STACK_SIZE
The amount of anticipated stack usage from the data cache
during pre-ram rom stage execution.
config MARK_GRAPHICS_MEM_WRCOMB
bool "Mark graphics memory as write-combining."
default n
help
The graphics performance may increase if the graphics
memory is set as write-combining cache type. This option
enables marking the graphics memory as write-combining.
config HAVE_MRC
bool "Add a System Agent binary"
help

View File

@ -217,12 +217,29 @@ static void gma_set_subsystem(device_t dev, unsigned vendor, unsigned device)
}
}
static void gma_read_resources(struct device *dev)
{
pci_dev_read_resources(dev);
#if CONFIG_MARK_GRAPHICS_MEM_WRCOMB
struct resource *res;
/* Set the graphics memory to write combining. */
res = find_resource(dev, PCI_BASE_ADDRESS_2);
if (res == NULL) {
printk(BIOS_DEBUG, "gma: memory resource not found.\n");
return;
}
res->flags |= IORESOURCE_WRCOMB;
#endif
}
static struct pci_operations gma_pci_ops = {
.set_subsystem = gma_set_subsystem,
};
static struct device_operations gma_func0_ops = {
.read_resources = pci_dev_read_resources,
.read_resources = gma_read_resources,
.set_resources = pci_dev_set_resources,
.enable_resources = pci_dev_enable_resources,
.init = gma_func0_init,