1 // SPDX-License-Identifier: MIT
3 * Copyright © 2020 Intel Corporation
7 #include <linux/pagemap.h>
8 #include <linux/shmem_fs.h>
10 #include "gem/i915_gem_object.h"
11 #include "shmem_utils.h"
13 struct file *shmem_create_from_data(const char *name, void *data, size_t len)
18 file = shmem_file_setup(name, PAGE_ALIGN(len), VM_NORESERVE);
22 err = shmem_write(file, 0, data, len);
31 struct file *shmem_create_from_object(struct drm_i915_gem_object *obj)
36 if (i915_gem_object_is_shmem(obj)) {
37 file = obj->base.filp;
38 atomic_long_inc(&file->f_count);
42 ptr = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WB);
46 file = shmem_create_from_data("", ptr, obj->base.size);
47 i915_gem_object_unpin_map(obj);
52 void *shmem_pin_map(struct file *file)
58 n_pages = file->f_mapping->host->i_size >> PAGE_SHIFT;
59 pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
63 for (i = 0; i < n_pages; i++) {
64 pages[i] = shmem_read_mapping_page_gfp(file->f_mapping, i,
70 vaddr = vmap(pages, n_pages, VM_MAP_PUT_PAGES, PAGE_KERNEL);
73 mapping_set_unevictable(file->f_mapping);
82 void shmem_unpin_map(struct file *file, void *ptr)
84 mapping_clear_unevictable(file->f_mapping);
88 static int __shmem_rw(struct file *file, loff_t off,
89 void *ptr, size_t len,
94 for (pfn = off >> PAGE_SHIFT; len; pfn++) {
96 min_t(size_t, PAGE_SIZE - offset_in_page(off), len);
100 page = shmem_read_mapping_page_gfp(file->f_mapping, pfn,
103 return PTR_ERR(page);
107 memcpy(vaddr + offset_in_page(off), ptr, this);
108 set_page_dirty(page);
110 memcpy(ptr, vaddr + offset_in_page(off), this);
112 mark_page_accessed(page);
124 int shmem_read(struct file *file, loff_t off, void *dst, size_t len)
126 return __shmem_rw(file, off, dst, len, false);
129 int shmem_write(struct file *file, loff_t off, void *src, size_t len)
131 return __shmem_rw(file, off, src, len, true);
134 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
135 #include "st_shmem_utils.c"