diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2010-12-22 11:37:09 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2011-02-22 15:52:41 +0000 |
| commit | bdb8b975fc66e081c3f39be6267701f8226d11aa (patch) | |
| tree | e4ff3068ea0844121372a3f88fa4d1f1a48edc35 /drivers/char/agp/intel-gtt.c | |
| parent | a36dbec57e9a665d69cd2e1a673153ddb2d62785 (diff) | |
agp/intel: Experiment with a 855GM GWB bit
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=27187
Tested-by: Thorsten Vollmer <thorsten@thvo.de> (DFI-ACP G5M150-N w/852GME)
Tested-by: Moritz Brunner <2points@gmx.org> (Asus M2400N/i855GM)
Tested-by: Indan Zupancic <indan@nul.nu> (Thinkpad X40/855GM rev 02)
Tested-by: Eric Anholt <eric@anholt.net> (865G)
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Diffstat (limited to 'drivers/char/agp/intel-gtt.c')
| -rw-r--r-- | drivers/char/agp/intel-gtt.c | 56 |
1 files changed, 21 insertions, 35 deletions
diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c index fab3d3265adb..0d09b537bb9a 100644 --- a/drivers/char/agp/intel-gtt.c +++ b/drivers/char/agp/intel-gtt.c @@ -21,6 +21,7 @@ #include <linux/kernel.h> #include <linux/pagemap.h> #include <linux/agp_backend.h> +#include <linux/delay.h> #include <asm/smp.h> #include "agp.h" #include "intel-agp.h" @@ -70,12 +71,8 @@ static struct _intel_private { u32 __iomem *gtt; /* I915G */ bool clear_fake_agp; /* on first access via agp, fill with scratch */ int num_dcache_entries; - union { - void __iomem *i9xx_flush_page; - void *i8xx_flush_page; - }; + void __iomem *i9xx_flush_page; char *i81x_gtt_table; - struct page *i8xx_page; struct resource ifp_resource; int resource_valid; struct page *scratch_page; @@ -722,28 +719,6 @@ static int intel_fake_agp_fetch_size(void) static void i830_cleanup(void) { - if (intel_private.i8xx_flush_page) { - kunmap(intel_private.i8xx_flush_page); - intel_private.i8xx_flush_page = NULL; - } - - __free_page(intel_private.i8xx_page); - intel_private.i8xx_page = NULL; -} - -static void intel_i830_setup_flush(void) -{ - /* return if we've already set the flush mechanism up */ - if (intel_private.i8xx_page) - return; - - intel_private.i8xx_page = alloc_page(GFP_KERNEL); - if (!intel_private.i8xx_page) - return; - - intel_private.i8xx_flush_page = kmap(intel_private.i8xx_page); - if (!intel_private.i8xx_flush_page) - i830_cleanup(); } /* The chipset_flush interface needs to get data that has already been @@ -758,14 +733,27 @@ static void intel_i830_setup_flush(void) */ static void i830_chipset_flush(void) { - unsigned int *pg = intel_private.i8xx_flush_page; + unsigned long timeout = jiffies + msecs_to_jiffies(1000); + + /* Forcibly evict everything from the CPU write buffers. + * clflush appears to be insufficient. + */ + wbinvd_on_all_cpus(); + + /* Now we've only seen documents for this magic bit on 855GM, + * we hope it exists for the other gen2 chipsets... + * + * Also works as advertised on my 845G. + */ + writel(readl(intel_private.registers+I830_HIC) | (1<<31), + intel_private.registers+I830_HIC); - memset(pg, 0, 1024); + while (readl(intel_private.registers+I830_HIC) & (1<<31)) { + if (time_after(jiffies, timeout)) + break; - if (cpu_has_clflush) - clflush_cache_range(pg, 1024); - else if (wbinvd_on_all_cpus() != 0) - printk(KERN_ERR "Timed out waiting for cache flush.\n"); + udelay(50); + } } static void i830_write_entry(dma_addr_t addr, unsigned int entry, @@ -849,8 +837,6 @@ static int i830_setup(void) intel_private.gtt_bus_addr = reg_addr + I810_PTE_BASE; - intel_i830_setup_flush(); - return 0; } |