From: Daniel Vetter Date: Sun, 25 Mar 2012 17:47:40 +0000 (+0200) Subject: drm/i915: extract copy helpers from shmem_pread|pwrite X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=d174bd6472d79fb5603dc8bd35e5184d83194ea8;p=~shefty%2Frdma-dev.git drm/i915: extract copy helpers from shmem_pread|pwrite While moving around things, this two functions slowly grew out of any sane bounds. So extract a few lines that do the copying and clflushing. Also add a few comments to explain what's going on. v2: Again do s/needs_clflush/needs_clflush_after/ in the write paths as suggested by Chris Wilson. Tested-by: Chris Wilson Reviewed-by: Chris Wilson Signed-Off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index c84060ce6bf..e9cac478cce 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -287,6 +287,60 @@ __copy_from_user_swizzled(char __user *gpu_vaddr, int gpu_offset, return 0; } +/* Per-page copy function for the shmem pread fastpath. + * Flushes invalid cachelines before reading the target if + * needs_clflush is set. */ +static int +shmem_pread_fast(struct page *page, int shmem_page_offset, int page_length, + char __user *user_data, + bool page_do_bit17_swizzling, bool needs_clflush) +{ + char *vaddr; + int ret; + + if (page_do_bit17_swizzling) + return -EINVAL; + + vaddr = kmap_atomic(page); + if (needs_clflush) + drm_clflush_virt_range(vaddr + shmem_page_offset, + page_length); + ret = __copy_to_user_inatomic(user_data, + vaddr + shmem_page_offset, + page_length); + kunmap_atomic(vaddr); + + return ret; +} + +/* Only difference to the fast-path function is that this can handle bit17 + * and uses non-atomic copy and kmap functions. */ +static int +shmem_pread_slow(struct page *page, int shmem_page_offset, int page_length, + char __user *user_data, + bool page_do_bit17_swizzling, bool needs_clflush) +{ + char *vaddr; + int ret; + + vaddr = kmap(page); + if (needs_clflush) + drm_clflush_virt_range(vaddr + shmem_page_offset, + page_length); + + if (page_do_bit17_swizzling) + ret = __copy_to_user_swizzled(user_data, + vaddr, shmem_page_offset, + page_length); + else + ret = __copy_to_user(user_data, + vaddr + shmem_page_offset, + page_length); + kunmap(page); + + return ret; +} + static int i915_gem_shmem_pread(struct drm_device *dev, struct drm_i915_gem_object *obj, @@ -325,7 +379,6 @@ i915_gem_shmem_pread(struct drm_device *dev, while (remain > 0) { struct page *page; - char *vaddr; /* Operation in this page * @@ -352,18 +405,11 @@ i915_gem_shmem_pread(struct drm_device *dev, page_do_bit17_swizzling = obj_do_bit17_swizzling && (page_to_phys(page) & (1 << 17)) != 0; - if (!page_do_bit17_swizzling) { - vaddr = kmap_atomic(page); - if (needs_clflush) - drm_clflush_virt_range(vaddr + shmem_page_offset, - page_length); - ret = __copy_to_user_inatomic(user_data, - vaddr + shmem_page_offset, - page_length); - kunmap_atomic(vaddr); - if (ret == 0) - goto next_page; - } + ret = shmem_pread_fast(page, shmem_page_offset, page_length, + user_data, page_do_bit17_swizzling, + needs_clflush); + if (ret == 0) + goto next_page; hit_slowpath = 1; page_cache_get(page); @@ -379,20 +425,9 @@ i915_gem_shmem_pread(struct drm_device *dev, prefaulted = 1; } - vaddr = kmap(page); - if (needs_clflush) - drm_clflush_virt_range(vaddr + shmem_page_offset, - page_length); - - if (page_do_bit17_swizzling) - ret = __copy_to_user_swizzled(user_data, - vaddr, shmem_page_offset, - page_length); - else - ret = __copy_to_user(user_data, - vaddr + shmem_page_offset, - page_length); - kunmap(page); + ret = shmem_pread_slow(page, shmem_page_offset, page_length, + user_data, page_do_bit17_swizzling, + needs_clflush); mutex_lock(&dev->struct_mutex); page_cache_release(page); @@ -557,6 +592,70 @@ out: return ret; } +/* Per-page copy function for the shmem pwrite fastpath. + * Flushes invalid cachelines before writing to the target if + * needs_clflush_before is set and flushes out any written cachelines after + * writing if needs_clflush is set. */ +static int +shmem_pwrite_fast(struct page *page, int shmem_page_offset, int page_length, + char __user *user_data, + bool page_do_bit17_swizzling, + bool needs_clflush_before, + bool needs_clflush_after) +{ + char *vaddr; + int ret; + + if (page_do_bit17_swizzling) + return -EINVAL; + + vaddr = kmap_atomic(page); + if (needs_clflush_before) + drm_clflush_virt_range(vaddr + shmem_page_offset, + page_length); + ret = __copy_from_user_inatomic_nocache(vaddr + shmem_page_offset, + user_data, + page_length); + if (needs_clflush_after) + drm_clflush_virt_range(vaddr + shmem_page_offset, + page_length); + kunmap_atomic(vaddr); + + return ret; +} + +/* Only difference to the fast-path function is that this can handle bit17 + * and uses non-atomic copy and kmap functions. */ +static int +shmem_pwrite_slow(struct page *page, int shmem_page_offset, int page_length, + char __user *user_data, + bool page_do_bit17_swizzling, + bool needs_clflush_before, + bool needs_clflush_after) +{ + char *vaddr; + int ret; + + vaddr = kmap(page); + if (needs_clflush_before) + drm_clflush_virt_range(vaddr + shmem_page_offset, + page_length); + if (page_do_bit17_swizzling) + ret = __copy_from_user_swizzled(vaddr, shmem_page_offset, + user_data, + page_length); + else + ret = __copy_from_user(vaddr + shmem_page_offset, + user_data, + page_length); + if (needs_clflush_after) + drm_clflush_virt_range(vaddr + shmem_page_offset, + page_length); + kunmap(page); + + return ret; +} + static int i915_gem_shmem_pwrite(struct drm_device *dev, struct drm_i915_gem_object *obj, @@ -601,7 +700,6 @@ i915_gem_shmem_pwrite(struct drm_device *dev, while (remain > 0) { struct page *page; - char *vaddr; int partial_cacheline_write; /* Operation in this page @@ -637,43 +735,21 @@ i915_gem_shmem_pwrite(struct drm_device *dev, page_do_bit17_swizzling = obj_do_bit17_swizzling && (page_to_phys(page) & (1 << 17)) != 0; - if (!page_do_bit17_swizzling) { - vaddr = kmap_atomic(page); - if (partial_cacheline_write) - drm_clflush_virt_range(vaddr + shmem_page_offset, - page_length); - ret = __copy_from_user_inatomic_nocache(vaddr + shmem_page_offset, - user_data, - page_length); - if (needs_clflush_after) - drm_clflush_virt_range(vaddr + shmem_page_offset, - page_length); - kunmap_atomic(vaddr); - - if (ret == 0) - goto next_page; - } + ret = shmem_pwrite_fast(page, shmem_page_offset, page_length, + user_data, page_do_bit17_swizzling, + partial_cacheline_write, + needs_clflush_after); + if (ret == 0) + goto next_page; hit_slowpath = 1; page_cache_get(page); mutex_unlock(&dev->struct_mutex); - vaddr = kmap(page); - if (partial_cacheline_write) - drm_clflush_virt_range(vaddr + shmem_page_offset, - page_length); - if (page_do_bit17_swizzling) - ret = __copy_from_user_swizzled(vaddr, shmem_page_offset, - user_data, - page_length); - else - ret = __copy_from_user(vaddr + shmem_page_offset, - user_data, - page_length); - if (needs_clflush_after) - drm_clflush_virt_range(vaddr + shmem_page_offset, - page_length); - kunmap(page); + ret = shmem_pwrite_slow(page, shmem_page_offset, page_length, + user_data, page_do_bit17_swizzling, + partial_cacheline_write, + needs_clflush_after); mutex_lock(&dev->struct_mutex); page_cache_release(page);