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1// SPDX-License-Identifier: MIT2/*3 * Copyright © 2020 Intel Corporation4 */5 6#include <linux/iosys-map.h>7#include <linux/mm.h>8#include <linux/pagemap.h>9#include <linux/shmem_fs.h>10#include <linux/vmalloc.h>11 12#include "i915_drv.h"13#include "gem/i915_gem_object.h"14#include "gem/i915_gem_lmem.h"15#include "shmem_utils.h"16 17struct file *shmem_create_from_data(const char *name, void *data, size_t len)18{19 struct file *file;20 int err;21 22 file = shmem_file_setup(name, PAGE_ALIGN(len), VM_NORESERVE);23 if (IS_ERR(file))24 return file;25 26 err = shmem_write(file, 0, data, len);27 if (err) {28 fput(file);29 return ERR_PTR(err);30 }31 32 return file;33}34 35struct file *shmem_create_from_object(struct drm_i915_gem_object *obj)36{37 enum i915_map_type map_type;38 struct file *file;39 void *ptr;40 41 if (i915_gem_object_is_shmem(obj)) {42 file = obj->base.filp;43 atomic_long_inc(&file->f_count);44 return file;45 }46 47 map_type = i915_gem_object_is_lmem(obj) ? I915_MAP_WC : I915_MAP_WB;48 ptr = i915_gem_object_pin_map_unlocked(obj, map_type);49 if (IS_ERR(ptr))50 return ERR_CAST(ptr);51 52 file = shmem_create_from_data("", ptr, obj->base.size);53 i915_gem_object_unpin_map(obj);54 55 return file;56}57 58void *shmem_pin_map(struct file *file)59{60 struct page **pages;61 size_t n_pages, i;62 void *vaddr;63 64 n_pages = file->f_mapping->host->i_size >> PAGE_SHIFT;65 pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);66 if (!pages)67 return NULL;68 69 for (i = 0; i < n_pages; i++) {70 pages[i] = shmem_read_mapping_page_gfp(file->f_mapping, i,71 GFP_KERNEL);72 if (IS_ERR(pages[i]))73 goto err_page;74 }75 76 vaddr = vmap(pages, n_pages, VM_MAP_PUT_PAGES, PAGE_KERNEL);77 if (!vaddr)78 goto err_page;79 mapping_set_unevictable(file->f_mapping);80 return vaddr;81err_page:82 while (i--)83 put_page(pages[i]);84 kvfree(pages);85 return NULL;86}87 88void shmem_unpin_map(struct file *file, void *ptr)89{90 mapping_clear_unevictable(file->f_mapping);91 vfree(ptr);92}93 94static int __shmem_rw(struct file *file, loff_t off,95 void *ptr, size_t len,96 bool write)97{98 unsigned long pfn;99 100 for (pfn = off >> PAGE_SHIFT; len; pfn++) {101 unsigned int this =102 min_t(size_t, PAGE_SIZE - offset_in_page(off), len);103 struct page *page;104 void *vaddr;105 106 page = shmem_read_mapping_page_gfp(file->f_mapping, pfn,107 GFP_KERNEL);108 if (IS_ERR(page))109 return PTR_ERR(page);110 111 vaddr = kmap(page);112 if (write) {113 memcpy(vaddr + offset_in_page(off), ptr, this);114 set_page_dirty(page);115 } else {116 memcpy(ptr, vaddr + offset_in_page(off), this);117 }118 mark_page_accessed(page);119 kunmap(page);120 put_page(page);121 122 len -= this;123 ptr += this;124 off = 0;125 }126 127 return 0;128}129 130int shmem_read_to_iosys_map(struct file *file, loff_t off,131 struct iosys_map *map, size_t map_off, size_t len)132{133 unsigned long pfn;134 135 for (pfn = off >> PAGE_SHIFT; len; pfn++) {136 unsigned int this =137 min_t(size_t, PAGE_SIZE - offset_in_page(off), len);138 struct page *page;139 void *vaddr;140 141 page = shmem_read_mapping_page_gfp(file->f_mapping, pfn,142 GFP_KERNEL);143 if (IS_ERR(page))144 return PTR_ERR(page);145 146 vaddr = kmap(page);147 iosys_map_memcpy_to(map, map_off, vaddr + offset_in_page(off),148 this);149 mark_page_accessed(page);150 kunmap(page);151 put_page(page);152 153 len -= this;154 map_off += this;155 off = 0;156 }157 158 return 0;159}160 161int shmem_read(struct file *file, loff_t off, void *dst, size_t len)162{163 return __shmem_rw(file, off, dst, len, false);164}165 166int shmem_write(struct file *file, loff_t off, void *src, size_t len)167{168 return __shmem_rw(file, off, src, len, true);169}170 171#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)172#include "st_shmem_utils.c"173#endif174