From 0e3d208aee5b287d25b8f6be85ec5f4245ee83a0 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 22 Dec 2010 11:37:09 +0000 Subject: [PATCH] agp/intel: Experiment with a 855GM GWB bit Signed-off-by: Chris Wilson --- drivers/char/agp/intel-agp.h | 1 + drivers/char/agp/intel-gtt.c | 30 ++++++++++++++++++++++++++++-- 2 files changed, 29 insertions(+), 2 deletions(-) diff --git a/drivers/char/agp/intel-agp.h b/drivers/char/agp/intel-agp.h index 010e3de..5fef204 100644 --- a/drivers/char/agp/intel-agp.h +++ b/drivers/char/agp/intel-agp.h @@ -128,6 +128,7 @@ #define INTEL_GMCH_GMS_STOLEN_352M (0xd << 4) #define I915_IFPADDR 0x60 +#define I830_HIC 0x70 /* Intel 965G registers */ #define I965_MSAC 0x62 diff --git a/drivers/char/agp/intel-gtt.c b/drivers/char/agp/intel-gtt.c index 356f73e..799ad17 100644 --- a/drivers/char/agp/intel-gtt.c +++ b/drivers/char/agp/intel-gtt.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include "agp.h" #include "intel-agp.h" @@ -61,6 +62,7 @@ struct intel_gtt_driver { static struct _intel_private { struct intel_gtt base; const struct intel_gtt_driver *driver; + unsigned int gmch_chip_id; struct pci_dev *pcidev; /* device one */ struct pci_dev *bridge_dev; u8 __iomem *registers; @@ -86,6 +88,7 @@ static struct _intel_private { #define IS_PINEVIEW intel_private.driver->is_pineview #define IS_IRONLAKE intel_private.driver->is_ironlake #define HAS_PGTBL_EN intel_private.driver->has_pgtbl_enable +#define IS_855GM (intel_private.gmch_chip_id == PCI_DEVICE_ID_INTEL_82855GM_IG) int intel_gtt_map_memory(struct page **pages, unsigned int num_entries, struct scatterlist **sg_list, int *num_sg) @@ -745,6 +748,24 @@ static void intel_i830_setup_flush(void) i830_cleanup(); } +static void i855_chipset_flush(void) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(1000); + + /* Now we've only seen documents for this magic bit on 855GM, + * we hope it exists for the other gen2 chipsets... + */ + writel(readl(intel_private.registers+I830_HIC) | (1<<31), + intel_private.registers+I830_HIC); + + while (readl(intel_private.registers+I830_HIC) & (1<<31)) { + if (time_after(jiffies, timeout)) + break; + + udelay(50); + } +} + /* 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. @@ -757,10 +778,13 @@ static void intel_i830_setup_flush(void) */ static void i830_chipset_flush(void) { - unsigned int *pg = intel_private.i8xx_flush_page; + unsigned int *pg; - memset(pg, 0, 1024); + if (IS_855GM) + return i855_chipset_flush(); + pg = intel_private.i8xx_flush_page; + memset(pg, 0, 1024); if (cpu_has_clflush) clflush_cache_range(pg, 1024); else if (wbinvd_on_all_cpus() != 0) @@ -1456,6 +1480,8 @@ int intel_gmch_probe(struct pci_dev *pdev, if (find_gmch(intel_gtt_chipsets[i].gmch_chip_id)) { intel_private.driver = intel_gtt_chipsets[i].gtt_driver; + intel_private.gmch_chip_id = + intel_gtt_chipsets[i].gmch_chip_id; break; } } -- 1.7.2.3