1*4882a593Smuzhiyun // SPDX-License-Identifier: MIT
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright © 2020 Intel Corporation
4*4882a593Smuzhiyun */
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun #include <linux/mm.h>
7*4882a593Smuzhiyun #include <linux/pagemap.h>
8*4882a593Smuzhiyun #include <linux/shmem_fs.h>
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include "gem/i915_gem_object.h"
11*4882a593Smuzhiyun #include "shmem_utils.h"
12*4882a593Smuzhiyun
shmem_create_from_data(const char * name,void * data,size_t len)13*4882a593Smuzhiyun struct file *shmem_create_from_data(const char *name, void *data, size_t len)
14*4882a593Smuzhiyun {
15*4882a593Smuzhiyun struct file *file;
16*4882a593Smuzhiyun int err;
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun file = shmem_file_setup(name, PAGE_ALIGN(len), VM_NORESERVE);
19*4882a593Smuzhiyun if (IS_ERR(file))
20*4882a593Smuzhiyun return file;
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun err = shmem_write(file, 0, data, len);
23*4882a593Smuzhiyun if (err) {
24*4882a593Smuzhiyun fput(file);
25*4882a593Smuzhiyun return ERR_PTR(err);
26*4882a593Smuzhiyun }
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun return file;
29*4882a593Smuzhiyun }
30*4882a593Smuzhiyun
shmem_create_from_object(struct drm_i915_gem_object * obj)31*4882a593Smuzhiyun struct file *shmem_create_from_object(struct drm_i915_gem_object *obj)
32*4882a593Smuzhiyun {
33*4882a593Smuzhiyun struct file *file;
34*4882a593Smuzhiyun void *ptr;
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun if (obj->ops == &i915_gem_shmem_ops) {
37*4882a593Smuzhiyun file = obj->base.filp;
38*4882a593Smuzhiyun atomic_long_inc(&file->f_count);
39*4882a593Smuzhiyun return file;
40*4882a593Smuzhiyun }
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun ptr = i915_gem_object_pin_map(obj, I915_MAP_WB);
43*4882a593Smuzhiyun if (IS_ERR(ptr))
44*4882a593Smuzhiyun return ERR_CAST(ptr);
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun file = shmem_create_from_data("", ptr, obj->base.size);
47*4882a593Smuzhiyun i915_gem_object_unpin_map(obj);
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun return file;
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun
shmem_pin_map(struct file * file)52*4882a593Smuzhiyun void *shmem_pin_map(struct file *file)
53*4882a593Smuzhiyun {
54*4882a593Smuzhiyun struct page **pages;
55*4882a593Smuzhiyun size_t n_pages, i;
56*4882a593Smuzhiyun void *vaddr;
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun n_pages = file->f_mapping->host->i_size >> PAGE_SHIFT;
59*4882a593Smuzhiyun pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
60*4882a593Smuzhiyun if (!pages)
61*4882a593Smuzhiyun return NULL;
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun for (i = 0; i < n_pages; i++) {
64*4882a593Smuzhiyun pages[i] = shmem_read_mapping_page_gfp(file->f_mapping, i,
65*4882a593Smuzhiyun GFP_KERNEL);
66*4882a593Smuzhiyun if (IS_ERR(pages[i]))
67*4882a593Smuzhiyun goto err_page;
68*4882a593Smuzhiyun }
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun vaddr = vmap(pages, n_pages, VM_MAP_PUT_PAGES, PAGE_KERNEL);
71*4882a593Smuzhiyun if (!vaddr)
72*4882a593Smuzhiyun goto err_page;
73*4882a593Smuzhiyun mapping_set_unevictable(file->f_mapping);
74*4882a593Smuzhiyun return vaddr;
75*4882a593Smuzhiyun err_page:
76*4882a593Smuzhiyun while (i--)
77*4882a593Smuzhiyun put_page(pages[i]);
78*4882a593Smuzhiyun kvfree(pages);
79*4882a593Smuzhiyun return NULL;
80*4882a593Smuzhiyun }
81*4882a593Smuzhiyun
shmem_unpin_map(struct file * file,void * ptr)82*4882a593Smuzhiyun void shmem_unpin_map(struct file *file, void *ptr)
83*4882a593Smuzhiyun {
84*4882a593Smuzhiyun mapping_clear_unevictable(file->f_mapping);
85*4882a593Smuzhiyun vfree(ptr);
86*4882a593Smuzhiyun }
87*4882a593Smuzhiyun
__shmem_rw(struct file * file,loff_t off,void * ptr,size_t len,bool write)88*4882a593Smuzhiyun static int __shmem_rw(struct file *file, loff_t off,
89*4882a593Smuzhiyun void *ptr, size_t len,
90*4882a593Smuzhiyun bool write)
91*4882a593Smuzhiyun {
92*4882a593Smuzhiyun unsigned long pfn;
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun for (pfn = off >> PAGE_SHIFT; len; pfn++) {
95*4882a593Smuzhiyun unsigned int this =
96*4882a593Smuzhiyun min_t(size_t, PAGE_SIZE - offset_in_page(off), len);
97*4882a593Smuzhiyun struct page *page;
98*4882a593Smuzhiyun void *vaddr;
99*4882a593Smuzhiyun
100*4882a593Smuzhiyun page = shmem_read_mapping_page_gfp(file->f_mapping, pfn,
101*4882a593Smuzhiyun GFP_KERNEL);
102*4882a593Smuzhiyun if (IS_ERR(page))
103*4882a593Smuzhiyun return PTR_ERR(page);
104*4882a593Smuzhiyun
105*4882a593Smuzhiyun vaddr = kmap(page);
106*4882a593Smuzhiyun if (write) {
107*4882a593Smuzhiyun memcpy(vaddr + offset_in_page(off), ptr, this);
108*4882a593Smuzhiyun set_page_dirty(page);
109*4882a593Smuzhiyun } else {
110*4882a593Smuzhiyun memcpy(ptr, vaddr + offset_in_page(off), this);
111*4882a593Smuzhiyun }
112*4882a593Smuzhiyun mark_page_accessed(page);
113*4882a593Smuzhiyun kunmap(page);
114*4882a593Smuzhiyun put_page(page);
115*4882a593Smuzhiyun
116*4882a593Smuzhiyun len -= this;
117*4882a593Smuzhiyun ptr += this;
118*4882a593Smuzhiyun off = 0;
119*4882a593Smuzhiyun }
120*4882a593Smuzhiyun
121*4882a593Smuzhiyun return 0;
122*4882a593Smuzhiyun }
123*4882a593Smuzhiyun
shmem_read(struct file * file,loff_t off,void * dst,size_t len)124*4882a593Smuzhiyun int shmem_read(struct file *file, loff_t off, void *dst, size_t len)
125*4882a593Smuzhiyun {
126*4882a593Smuzhiyun return __shmem_rw(file, off, dst, len, false);
127*4882a593Smuzhiyun }
128*4882a593Smuzhiyun
shmem_write(struct file * file,loff_t off,void * src,size_t len)129*4882a593Smuzhiyun int shmem_write(struct file *file, loff_t off, void *src, size_t len)
130*4882a593Smuzhiyun {
131*4882a593Smuzhiyun return __shmem_rw(file, off, src, len, true);
132*4882a593Smuzhiyun }
133*4882a593Smuzhiyun
134*4882a593Smuzhiyun #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
135*4882a593Smuzhiyun #include "st_shmem_utils.c"
136*4882a593Smuzhiyun #endif
137