From: Linus Torvalds Date: Wed, 22 Nov 2006 17:37:54 +0000 (-0800) Subject: [AGP] Fix intel 965 AGP memory mapping function X-Git-Tag: v2.6.19~53 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7d915a38985d2826acbdc9dc9cca8a93e23e5278;p=linux-2.6 [AGP] Fix intel 965 AGP memory mapping function This introduces a i965-specific "mask_memory()" function that knows about the extended physical addresses that the i965 supports. This allows us to correctly map in physical memory in the >4GB range into the GTT. Also simplify/clean-up the i965 case for the aperture sizing by just returning the fixed 512kB size from "fetch_size()". We don't really care that not all of the aperture may be visible - the only thing that cares about the aperture size is the Intel "stolen memory" calculation, which depends on the fixed size. Cc: Keith Packard Cc: Eric Anholt Cc: Dave Jones Signed-off-by: Linus Torvalds --- diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c index d1ede7db5a..aceece71a8 100644 --- a/drivers/char/agp/intel-agp.c +++ b/drivers/char/agp/intel-agp.c @@ -387,11 +387,7 @@ static void intel_i830_init_gtt_entries(void) /* We obtain the size of the GTT, which is also stored (for some * reason) at the top of stolen memory. Then we add 4KB to that * for the video BIOS popup, which is also stored in there. */ - - if (IS_I965) - size = 512 + 4; - else - size = agp_bridge->driver->fetch_size() + 4; + size = agp_bridge->driver->fetch_size() + 4; if (agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82830_HB || agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82845G_HB) { @@ -805,6 +801,26 @@ static int intel_i915_create_gatt_table(struct agp_bridge_data *bridge) return 0; } + +/* + * The i965 supports 36-bit physical addresses, but to keep + * the format of the GTT the same, the bits that don't fit + * in a 32-bit word are shifted down to bits 4..7. + * + * Gcc is smart enough to notice that "(addr >> 28) & 0xf0" + * is always zero on 32-bit architectures, so no need to make + * this conditional. + */ +static unsigned long intel_i965_mask_memory(struct agp_bridge_data *bridge, + unsigned long addr, int type) +{ + /* Shift high bits down */ + addr |= (addr >> 28) & 0xf0; + + /* Type checking must be done elsewhere */ + return addr | bridge->driver->masks[type].mask; +} + static int intel_i965_fetch_size(void) { struct aper_size_info_fixed *values; @@ -832,7 +848,8 @@ static int intel_i965_fetch_size(void) agp_bridge->previous_size = agp_bridge->current_size = (void *)(values + offset); - return values[offset].size; + /* The i965 GTT is always sized as if it had a 512kB aperture size */ + return 512; } /* The intel i965 automatically initializes the agp aperture during POST. @@ -1584,7 +1601,7 @@ static struct agp_bridge_driver intel_i965_driver = { .fetch_size = intel_i965_fetch_size, .cleanup = intel_i915_cleanup, .tlb_flush = intel_i810_tlbflush, - .mask_memory = intel_i810_mask_memory, + .mask_memory = intel_i965_mask_memory, .masks = intel_i810_masks, .agp_enable = intel_i810_agp_enable, .cache_flush = global_cache_flush,