Like for shmem_pwrite_slow. The only difference is that because we read data, we can leave the fetched cachelines in the cpu: In the case that the object isn't in the cpu read domain anymore, the clflush for the next cpu read domain invalidation will simply drop these cachelines. slow_shmem_bit17_copy is now ununsed, so kill it. With this patch tests/gem_mmap_gtt now actually works. v2: add __ to copy_to_user_swizzled as suggested by Chris Wilson. v3: Fixup the swizzling logic, it swizzled the wrong pages. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=38115 Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch> --- drivers/gpu/drm/i915/i915_gem.c | 191 ++++++++++++--------------------------- 1 files changed, 57 insertions(+), 134 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 5c3f96c..6bc06b1 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -257,73 +257,6 @@ static int i915_gem_object_needs_bit17_swizzle(struct drm_i915_gem_object *obj) obj->tiling_mode != I915_TILING_NONE; } -static inline void -slow_shmem_copy(struct page *dst_page, - int dst_offset, - struct page *src_page, - int src_offset, - int length) -{ - char *dst_vaddr, *src_vaddr; - - dst_vaddr = kmap(dst_page); - src_vaddr = kmap(src_page); - - memcpy(dst_vaddr + dst_offset, src_vaddr + src_offset, length); - - kunmap(src_page); - kunmap(dst_page); -} - -static inline void -slow_shmem_bit17_copy(struct page *gpu_page, - int gpu_offset, - struct page *cpu_page, - int cpu_offset, - int length, - int is_read) -{ - char *gpu_vaddr, *cpu_vaddr; - - /* Use the unswizzled path if this page isn't affected. */ - if ((page_to_phys(gpu_page) & (1 << 17)) == 0) { - if (is_read) - return slow_shmem_copy(cpu_page, cpu_offset, - gpu_page, gpu_offset, length); - else - return slow_shmem_copy(gpu_page, gpu_offset, - cpu_page, cpu_offset, length); - } - - gpu_vaddr = kmap(gpu_page); - cpu_vaddr = kmap(cpu_page); - - /* Copy the data, XORing A6 with A17 (1). The user already knows he's - * XORing with the other bits (A9 for Y, A9 and A10 for X) - */ - while (length > 0) { - int cacheline_end = ALIGN(gpu_offset + 1, 64); - int this_length = min(cacheline_end - gpu_offset, length); - int swizzled_gpu_offset = gpu_offset ^ 64; - - if (is_read) { - memcpy(cpu_vaddr + cpu_offset, - gpu_vaddr + swizzled_gpu_offset, - this_length); - } else { - memcpy(gpu_vaddr + swizzled_gpu_offset, - cpu_vaddr + cpu_offset, - this_length); - } - cpu_offset += this_length; - gpu_offset += this_length; - length -= this_length; - } - - kunmap(cpu_page); - kunmap(gpu_page); -} - /** * This is the fast shmem pread path, which attempts to copy_from_user directly * from the backing pages of the object to the user's address space. On a @@ -385,6 +318,32 @@ i915_gem_shmem_pread_fast(struct drm_device *dev, } static inline int +__copy_to_user_swizzled(char __user *cpu_vaddr, + const char *gpu_vaddr, int gpu_offset, + int length) +{ + int ret, cpu_offset = 0; + + while (length > 0) { + int cacheline_end = ALIGN(gpu_offset + 1, 64); + int this_length = min(cacheline_end - gpu_offset, length); + int swizzled_gpu_offset = gpu_offset ^ 64; + + ret = __copy_to_user(cpu_vaddr + cpu_offset, + gpu_vaddr + swizzled_gpu_offset, + this_length); + if (ret) + return ret + length; + + cpu_offset += this_length; + gpu_offset += this_length; + length -= this_length; + } + + return 0; +} + +static inline int __copy_from_user_swizzled(char __user *gpu_vaddr, int gpu_offset, const char *cpu_vaddr, int length) @@ -423,72 +382,34 @@ i915_gem_shmem_pread_slow(struct drm_device *dev, struct drm_file *file) { struct address_space *mapping = obj->base.filp->f_path.dentry->d_inode->i_mapping; - struct mm_struct *mm = current->mm; - struct page **user_pages; + char __user *user_data; ssize_t remain; - loff_t offset, pinned_pages, i; - loff_t first_data_page, last_data_page, num_pages; - int shmem_page_offset; - int data_page_index, data_page_offset; - int page_length; - int ret; - uint64_t data_ptr = args->data_ptr; - int do_bit17_swizzling; + loff_t offset; + int shmem_page_offset, page_length, ret; + int obj_do_bit17_swizzling, page_do_bit17_swizzling; + user_data = (char __user *) (uintptr_t) args->data_ptr; remain = args->size; - /* Pin the user pages containing the data. We can't fault while - * holding the struct mutex, yet we want to hold it while - * dereferencing the user data. - */ - first_data_page = data_ptr / PAGE_SIZE; - last_data_page = (data_ptr + args->size - 1) / PAGE_SIZE; - num_pages = last_data_page - first_data_page + 1; + obj_do_bit17_swizzling = i915_gem_object_needs_bit17_swizzle(obj); - user_pages = drm_malloc_ab(num_pages, sizeof(struct page *)); - if (user_pages == NULL) - return -ENOMEM; + offset = args->offset; mutex_unlock(&dev->struct_mutex); - down_read(&mm->mmap_sem); - pinned_pages = get_user_pages(current, mm, (uintptr_t)args->data_ptr, - num_pages, 1, 0, user_pages, NULL); - up_read(&mm->mmap_sem); - mutex_lock(&dev->struct_mutex); - if (pinned_pages < num_pages) { - ret = -EFAULT; - goto out; - } - - ret = i915_gem_object_set_cpu_read_domain_range(obj, - args->offset, - args->size); - if (ret) - goto out; - - do_bit17_swizzling = i915_gem_object_needs_bit17_swizzle(obj); - - offset = args->offset; while (remain > 0) { struct page *page; + char *vaddr; /* Operation in this page * * shmem_page_offset = offset within page in shmem file - * data_page_index = page number in get_user_pages return - * data_page_offset = offset with data_page_index page. * page_length = bytes to copy for this page */ shmem_page_offset = offset_in_page(offset); - data_page_index = data_ptr / PAGE_SIZE - first_data_page; - data_page_offset = offset_in_page(data_ptr); - page_length = remain; if ((shmem_page_offset + page_length) > PAGE_SIZE) page_length = PAGE_SIZE - shmem_page_offset; - if ((data_page_offset + page_length) > PAGE_SIZE) - page_length = PAGE_SIZE - data_page_offset; page = shmem_read_mapping_page(mapping, offset >> PAGE_SHIFT); if (IS_ERR(page)) { @@ -496,36 +417,38 @@ i915_gem_shmem_pread_slow(struct drm_device *dev, goto out; } - if (do_bit17_swizzling) { - slow_shmem_bit17_copy(page, - shmem_page_offset, - user_pages[data_page_index], - data_page_offset, - page_length, - 1); - } else { - slow_shmem_copy(user_pages[data_page_index], - data_page_offset, - page, - shmem_page_offset, - page_length); - } + page_do_bit17_swizzling = obj_do_bit17_swizzling && + (page_to_phys(page) & (1 << 17)) != 0; + + vaddr = kmap(page); + 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); mark_page_accessed(page); page_cache_release(page); + if (ret) { + ret = -EFAULT; + goto out; + } + remain -= page_length; - data_ptr += page_length; + user_data += page_length; offset += page_length; } out: - for (i = 0; i < pinned_pages; i++) { - SetPageDirty(user_pages[i]); - mark_page_accessed(user_pages[i]); - page_cache_release(user_pages[i]); - } - drm_free_large(user_pages); + mutex_lock(&dev->struct_mutex); + /* Fixup: Kill any reinstated backing storage pages */ + if (obj->madv == __I915_MADV_PURGED) + i915_gem_object_truncate(obj); return ret; } -- 1.7.6.4
