1 // SPDX-License-Identifier: MIT 2 /* 3 * Copyright © 2020 Intel Corporation 4 */ 5 6 #include <linux/iosys-map.h> 7 #include <linux/mm.h> 8 #include <linux/pagemap.h> 9 #include <linux/shmem_fs.h> 10 11 #include "i915_drv.h" 12 #include "gem/i915_gem_object.h" 13 #include "gem/i915_gem_lmem.h" 14 #include "shmem_utils.h" 15 16 struct file *shmem_create_from_data(const char *name, void *data, size_t len) 17 { 18 struct file *file; 19 int err; 20 21 file = shmem_file_setup(name, PAGE_ALIGN(len), VM_NORESERVE); 22 if (IS_ERR(file)) 23 return file; 24 25 err = shmem_write(file, 0, data, len); 26 if (err) { 27 fput(file); 28 return ERR_PTR(err); 29 } 30 31 return file; 32 } 33 34 struct file *shmem_create_from_object(struct drm_i915_gem_object *obj) 35 { 36 struct drm_i915_private *i915 = to_i915(obj->base.dev); 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_coherent_map_type(i915, obj, true); 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 58 void *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; 81 err_page: 82 while (i--) 83 put_page(pages[i]); 84 kvfree(pages); 85 return NULL; 86 } 87 88 void shmem_unpin_map(struct file *file, void *ptr) 89 { 90 mapping_clear_unevictable(file->f_mapping); 91 vfree(ptr); 92 } 93 94 static 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 } 129 130 int 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 } 160 161 int shmem_read(struct file *file, loff_t off, void *dst, size_t len) 162 { 163 return __shmem_rw(file, off, dst, len, false); 164 } 165 166 int 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 #endif 174