1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * NVM helpers 4 * 5 * Copyright (C) 2020, Intel Corporation 6 * Author: Mika Westerberg <mika.westerberg@linux.intel.com> 7 */ 8 9 #include <linux/idr.h> 10 #include <linux/slab.h> 11 #include <linux/vmalloc.h> 12 13 #include "tb.h" 14 15 static DEFINE_IDA(nvm_ida); 16 17 /** 18 * tb_nvm_alloc() - Allocate new NVM structure 19 * @dev: Device owning the NVM 20 * 21 * Allocates new NVM structure with unique @id and returns it. In case 22 * of error returns ERR_PTR(). 23 */ 24 struct tb_nvm *tb_nvm_alloc(struct device *dev) 25 { 26 struct tb_nvm *nvm; 27 int ret; 28 29 nvm = kzalloc(sizeof(*nvm), GFP_KERNEL); 30 if (!nvm) 31 return ERR_PTR(-ENOMEM); 32 33 ret = ida_simple_get(&nvm_ida, 0, 0, GFP_KERNEL); 34 if (ret < 0) { 35 kfree(nvm); 36 return ERR_PTR(ret); 37 } 38 39 nvm->id = ret; 40 nvm->dev = dev; 41 42 return nvm; 43 } 44 45 /** 46 * tb_nvm_add_active() - Adds active NVMem device to NVM 47 * @nvm: NVM structure 48 * @size: Size of the active NVM in bytes 49 * @reg_read: Pointer to the function to read the NVM (passed directly to the 50 * NVMem device) 51 * 52 * Registers new active NVmem device for @nvm. The @reg_read is called 53 * directly from NVMem so it must handle possible concurrent access if 54 * needed. The first parameter passed to @reg_read is @nvm structure. 55 * Returns %0 in success and negative errno otherwise. 56 */ 57 int tb_nvm_add_active(struct tb_nvm *nvm, size_t size, nvmem_reg_read_t reg_read) 58 { 59 struct nvmem_config config; 60 struct nvmem_device *nvmem; 61 62 memset(&config, 0, sizeof(config)); 63 64 config.name = "nvm_active"; 65 config.reg_read = reg_read; 66 config.read_only = true; 67 config.id = nvm->id; 68 config.stride = 4; 69 config.word_size = 4; 70 config.size = size; 71 config.dev = nvm->dev; 72 config.owner = THIS_MODULE; 73 config.priv = nvm; 74 75 nvmem = nvmem_register(&config); 76 if (IS_ERR(nvmem)) 77 return PTR_ERR(nvmem); 78 79 nvm->active = nvmem; 80 return 0; 81 } 82 83 /** 84 * tb_nvm_write_buf() - Write data to @nvm buffer 85 * @nvm: NVM structure 86 * @offset: Offset where to write the data 87 * @val: Data buffer to write 88 * @bytes: Number of bytes to write 89 * 90 * Helper function to cache the new NVM image before it is actually 91 * written to the flash. Copies @bytes from @val to @nvm->buf starting 92 * from @offset. 93 */ 94 int tb_nvm_write_buf(struct tb_nvm *nvm, unsigned int offset, void *val, 95 size_t bytes) 96 { 97 if (!nvm->buf) { 98 nvm->buf = vmalloc(NVM_MAX_SIZE); 99 if (!nvm->buf) 100 return -ENOMEM; 101 } 102 103 nvm->flushed = false; 104 nvm->buf_data_size = offset + bytes; 105 memcpy(nvm->buf + offset, val, bytes); 106 return 0; 107 } 108 109 /** 110 * tb_nvm_add_non_active() - Adds non-active NVMem device to NVM 111 * @nvm: NVM structure 112 * @size: Size of the non-active NVM in bytes 113 * @reg_write: Pointer to the function to write the NVM (passed directly 114 * to the NVMem device) 115 * 116 * Registers new non-active NVmem device for @nvm. The @reg_write is called 117 * directly from NVMem so it must handle possible concurrent access if 118 * needed. The first parameter passed to @reg_write is @nvm structure. 119 * Returns %0 in success and negative errno otherwise. 120 */ 121 int tb_nvm_add_non_active(struct tb_nvm *nvm, size_t size, 122 nvmem_reg_write_t reg_write) 123 { 124 struct nvmem_config config; 125 struct nvmem_device *nvmem; 126 127 memset(&config, 0, sizeof(config)); 128 129 config.name = "nvm_non_active"; 130 config.reg_write = reg_write; 131 config.root_only = true; 132 config.id = nvm->id; 133 config.stride = 4; 134 config.word_size = 4; 135 config.size = size; 136 config.dev = nvm->dev; 137 config.owner = THIS_MODULE; 138 config.priv = nvm; 139 140 nvmem = nvmem_register(&config); 141 if (IS_ERR(nvmem)) 142 return PTR_ERR(nvmem); 143 144 nvm->non_active = nvmem; 145 return 0; 146 } 147 148 /** 149 * tb_nvm_free() - Release NVM and its resources 150 * @nvm: NVM structure to release 151 * 152 * Releases NVM and the NVMem devices if they were registered. 153 */ 154 void tb_nvm_free(struct tb_nvm *nvm) 155 { 156 if (nvm) { 157 nvmem_unregister(nvm->non_active); 158 nvmem_unregister(nvm->active); 159 vfree(nvm->buf); 160 ida_simple_remove(&nvm_ida, nvm->id); 161 } 162 kfree(nvm); 163 } 164 165 /** 166 * tb_nvm_read_data() - Read data from NVM 167 * @address: Start address on the flash 168 * @buf: Buffer where the read data is copied 169 * @size: Size of the buffer in bytes 170 * @retries: Number of retries if block read fails 171 * @read_block: Function that reads block from the flash 172 * @read_block_data: Data passsed to @read_block 173 * 174 * This is a generic function that reads data from NVM or NVM like 175 * device. 176 * 177 * Returns %0 on success and negative errno otherwise. 178 */ 179 int tb_nvm_read_data(unsigned int address, void *buf, size_t size, 180 unsigned int retries, read_block_fn read_block, 181 void *read_block_data) 182 { 183 do { 184 unsigned int dwaddress, dwords, offset; 185 u8 data[NVM_DATA_DWORDS * 4]; 186 size_t nbytes; 187 int ret; 188 189 offset = address & 3; 190 nbytes = min_t(size_t, size + offset, NVM_DATA_DWORDS * 4); 191 192 dwaddress = address / 4; 193 dwords = ALIGN(nbytes, 4) / 4; 194 195 ret = read_block(read_block_data, dwaddress, data, dwords); 196 if (ret) { 197 if (ret != -ENODEV && retries--) 198 continue; 199 return ret; 200 } 201 202 nbytes -= offset; 203 memcpy(buf, data + offset, nbytes); 204 205 size -= nbytes; 206 address += nbytes; 207 buf += nbytes; 208 } while (size > 0); 209 210 return 0; 211 } 212 213 /** 214 * tb_nvm_write_data() - Write data to NVM 215 * @address: Start address on the flash 216 * @buf: Buffer where the data is copied from 217 * @size: Size of the buffer in bytes 218 * @retries: Number of retries if the block write fails 219 * @write_block: Function that writes block to the flash 220 * @write_block_data: Data passwd to @write_block 221 * 222 * This is generic function that writes data to NVM or NVM like device. 223 * 224 * Returns %0 on success and negative errno otherwise. 225 */ 226 int tb_nvm_write_data(unsigned int address, const void *buf, size_t size, 227 unsigned int retries, write_block_fn write_block, 228 void *write_block_data) 229 { 230 do { 231 unsigned int offset, dwaddress; 232 u8 data[NVM_DATA_DWORDS * 4]; 233 size_t nbytes; 234 int ret; 235 236 offset = address & 3; 237 nbytes = min_t(u32, size + offset, NVM_DATA_DWORDS * 4); 238 239 memcpy(data + offset, buf, nbytes); 240 241 dwaddress = address / 4; 242 ret = write_block(write_block_data, dwaddress, data, nbytes / 4); 243 if (ret) { 244 if (ret == -ETIMEDOUT) { 245 if (retries--) 246 continue; 247 ret = -EIO; 248 } 249 return ret; 250 } 251 252 size -= nbytes; 253 address += nbytes; 254 buf += nbytes; 255 } while (size > 0); 256 257 return 0; 258 } 259 260 void tb_nvm_exit(void) 261 { 262 ida_destroy(&nvm_ida); 263 } 264