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 #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 17 struct 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), 23 mk_vma_flags(VMA_NORESERVE_BIT)); 24 if (IS_ERR(file)) 25 return file; 26 27 err = shmem_write(file, 0, data, len); 28 if (err) { 29 fput(file); 30 return ERR_PTR(err); 31 } 32 33 return file; 34 } 35 36 struct file *shmem_create_from_object(struct drm_i915_gem_object *obj) 37 { 38 enum i915_map_type map_type; 39 struct file *file; 40 void *ptr; 41 42 if (i915_gem_object_is_shmem(obj)) { 43 file = obj->base.filp; 44 get_file(file); 45 return file; 46 } 47 48 map_type = i915_gem_object_is_lmem(obj) ? I915_MAP_WC : I915_MAP_WB; 49 ptr = i915_gem_object_pin_map_unlocked(obj, map_type); 50 if (IS_ERR(ptr)) 51 return ERR_CAST(ptr); 52 53 file = shmem_create_from_data("", ptr, obj->base.size); 54 i915_gem_object_unpin_map(obj); 55 56 return file; 57 } 58 59 void *shmem_pin_map(struct file *file) 60 { 61 struct page **pages; 62 size_t n_pages, i; 63 void *vaddr; 64 65 n_pages = file->f_mapping->host->i_size >> PAGE_SHIFT; 66 pages = kvmalloc_objs(*pages, n_pages); 67 if (!pages) 68 return NULL; 69 70 for (i = 0; i < n_pages; i++) { 71 pages[i] = shmem_read_mapping_page_gfp(file->f_mapping, i, 72 GFP_KERNEL); 73 if (IS_ERR(pages[i])) 74 goto err_page; 75 } 76 77 vaddr = vmap(pages, n_pages, VM_MAP_PUT_PAGES, PAGE_KERNEL); 78 if (!vaddr) 79 goto err_page; 80 mapping_set_unevictable(file->f_mapping); 81 return vaddr; 82 err_page: 83 while (i--) 84 put_page(pages[i]); 85 kvfree(pages); 86 return NULL; 87 } 88 89 void shmem_unpin_map(struct file *file, void *ptr) 90 { 91 mapping_clear_unevictable(file->f_mapping); 92 vfree(ptr); 93 } 94 95 static int __shmem_rw(struct file *file, loff_t off, 96 void *ptr, size_t len, 97 bool write) 98 { 99 unsigned long pfn; 100 101 for (pfn = off >> PAGE_SHIFT; len; pfn++) { 102 unsigned int this = 103 min_t(size_t, PAGE_SIZE - offset_in_page(off), len); 104 struct page *page; 105 void *vaddr; 106 107 page = shmem_read_mapping_page_gfp(file->f_mapping, pfn, 108 GFP_KERNEL); 109 if (IS_ERR(page)) 110 return PTR_ERR(page); 111 112 vaddr = kmap_local_page(page); 113 if (write) { 114 memcpy(vaddr + offset_in_page(off), ptr, this); 115 set_page_dirty(page); 116 } else { 117 memcpy(ptr, vaddr + offset_in_page(off), this); 118 } 119 mark_page_accessed(page); 120 kunmap_local(vaddr); 121 put_page(page); 122 123 len -= this; 124 ptr += this; 125 off = 0; 126 } 127 128 return 0; 129 } 130 131 int shmem_read_to_iosys_map(struct file *file, loff_t off, 132 struct iosys_map *map, size_t map_off, size_t len) 133 { 134 unsigned long pfn; 135 136 for (pfn = off >> PAGE_SHIFT; len; pfn++) { 137 unsigned int this = 138 min_t(size_t, PAGE_SIZE - offset_in_page(off), len); 139 struct page *page; 140 void *vaddr; 141 142 page = shmem_read_mapping_page_gfp(file->f_mapping, pfn, 143 GFP_KERNEL); 144 if (IS_ERR(page)) 145 return PTR_ERR(page); 146 147 vaddr = kmap_local_page(page); 148 iosys_map_memcpy_to(map, map_off, vaddr + offset_in_page(off), 149 this); 150 mark_page_accessed(page); 151 kunmap_local(vaddr); 152 put_page(page); 153 154 len -= this; 155 map_off += this; 156 off = 0; 157 } 158 159 return 0; 160 } 161 162 int shmem_read(struct file *file, loff_t off, void *dst, size_t len) 163 { 164 return __shmem_rw(file, off, dst, len, false); 165 } 166 167 int shmem_write(struct file *file, loff_t off, void *src, size_t len) 168 { 169 return __shmem_rw(file, off, src, len, true); 170 } 171 172 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) 173 #include "st_shmem_utils.c" 174 #endif 175