diff options
Diffstat (limited to 'drivers/char/agp/intel-agp.c')
| -rw-r--r-- | drivers/char/agp/intel-agp.c | 30 |
1 files changed, 23 insertions, 7 deletions
diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c index c1729171503..e8dc75fc33c 100644 --- a/drivers/char/agp/intel-agp.c +++ b/drivers/char/agp/intel-agp.c @@ -682,23 +682,39 @@ static void intel_i830_setup_flush(void) if (!intel_private.i8xx_page) return; - /* make page uncached */ - map_page_into_agp(intel_private.i8xx_page); - intel_private.i8xx_flush_page = kmap(intel_private.i8xx_page); if (!intel_private.i8xx_flush_page) intel_i830_fini_flush(); } +static void +do_wbinvd(void *null) +{ + wbinvd(); +} + +/* The chipset_flush interface needs to get data that has already been + * flushed out of the CPU all the way out to main memory, because the GPU + * doesn't snoop those buffers. + * + * The 8xx series doesn't have the same lovely interface for flushing the + * chipset write buffers that the later chips do. According to the 865 + * specs, it's 64 octwords, or 1KB. So, to get those previous things in + * that buffer out, we just fill 1KB and clflush it out, on the assumption + * that it'll push whatever was in there out. It appears to work. + */ static void intel_i830_chipset_flush(struct agp_bridge_data *bridge) { unsigned int *pg = intel_private.i8xx_flush_page; - int i; - for (i = 0; i < 256; i += 2) - *(pg + i) = i; + memset(pg, 0, 1024); - wmb(); + if (cpu_has_clflush) { + clflush_cache_range(pg, 1024); + } else { + if (on_each_cpu(do_wbinvd, NULL, 1) != 0) + printk(KERN_ERR "Timed out waiting for cache flush.\n"); + } } /* The intel i830 automatically initializes the agp aperture during POST. |