diff options
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem.c | 59 |
1 files changed, 36 insertions, 23 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 9ac73dd1b422..49c5a1798ac4 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -171,6 +171,36 @@ i915_gem_pread_ioctl(struct drm_device *dev, void *data, return 0; } +/* + * Try to write quickly with an atomic kmap. Return true on success. + * + * If this fails (which includes a partial write), we'll redo the whole + * thing with the slow version. + * + * This is a workaround for the low performance of iounmap (approximate + * 10% cpu cost on normal 3D workloads). kmap_atomic on HIGHMEM kernels + * happens to let us map card memory without taking IPIs. When the vmap + * rework lands we should be able to dump this hack. + */ +static inline int fast_user_write(unsigned long pfn, char __user *user_data, int l) +{ +#ifdef CONFIG_HIGHMEM + unsigned long unwritten; + char *vaddr_atomic; + + vaddr_atomic = kmap_atomic_pfn(pfn, KM_USER0); +#if WATCH_PWRITE + DRM_INFO("pwrite i %d o %d l %d pfn %ld vaddr %p\n", + i, o, l, pfn, vaddr_atomic); +#endif + unwritten = __copy_from_user_inatomic_nocache(vaddr_atomic + o, user_data, l); + kunmap_atomic(vaddr_atomic, KM_USER0); + return !unwritten; +#else + return 0; +#endif +} + static int i915_gem_gtt_pwrite(struct drm_device *dev, struct drm_gem_object *obj, struct drm_i915_gem_pwrite *args, @@ -180,12 +210,7 @@ i915_gem_gtt_pwrite(struct drm_device *dev, struct drm_gem_object *obj, ssize_t remain; loff_t offset; char __user *user_data; - char __iomem *vaddr; - char *vaddr_atomic; - int i, o, l; int ret = 0; - unsigned long pfn; - unsigned long unwritten; user_data = (char __user *) (uintptr_t) args->data_ptr; remain = args->size; @@ -209,6 +234,9 @@ i915_gem_gtt_pwrite(struct drm_device *dev, struct drm_gem_object *obj, obj_priv->dirty = 1; while (remain > 0) { + unsigned long pfn; + int i, o, l; + /* Operation in this page * * i = page number @@ -223,25 +251,10 @@ i915_gem_gtt_pwrite(struct drm_device *dev, struct drm_gem_object *obj, pfn = (dev->agp->base >> PAGE_SHIFT) + i; -#ifdef CONFIG_HIGHMEM - /* This is a workaround for the low performance of iounmap - * (approximate 10% cpu cost on normal 3D workloads). - * kmap_atomic on HIGHMEM kernels happens to let us map card - * memory without taking IPIs. When the vmap rework lands - * we should be able to dump this hack. - */ - vaddr_atomic = kmap_atomic_pfn(pfn, KM_USER0); -#if WATCH_PWRITE - DRM_INFO("pwrite i %d o %d l %d pfn %ld vaddr %p\n", - i, o, l, pfn, vaddr_atomic); -#endif - unwritten = __copy_from_user_inatomic_nocache(vaddr_atomic + o, - user_data, l); - kunmap_atomic(vaddr_atomic, KM_USER0); + if (!fast_user_write(pfn, user_data, l)) { + unsigned long unwritten; + char __iomem *vaddr; - if (unwritten) -#endif /* CONFIG_HIGHMEM */ - { vaddr = ioremap_wc(pfn << PAGE_SHIFT, PAGE_SIZE); #if WATCH_PWRITE DRM_INFO("pwrite slow i %d o %d l %d " |