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 if (nvm->non_active) 158 nvmem_unregister(nvm->non_active); 159 if (nvm->active) 160 nvmem_unregister(nvm->active); 161 vfree(nvm->buf); 162 ida_simple_remove(&nvm_ida, nvm->id); 163 } 164 kfree(nvm); 165 } 166 167 /** 168 * tb_nvm_read_data() - Read data from NVM 169 * @address: Start address on the flash 170 * @buf: Buffer where the read data is copied 171 * @size: Size of the buffer in bytes 172 * @retries: Number of retries if block read fails 173 * @read_block: Function that reads block from the flash 174 * @read_block_data: Data passsed to @read_block 175 * 176 * This is a generic function that reads data from NVM or NVM like 177 * device. 178 * 179 * Returns %0 on success and negative errno otherwise. 180 */ 181 int tb_nvm_read_data(unsigned int address, void *buf, size_t size, 182 unsigned int retries, read_block_fn read_block, 183 void *read_block_data) 184 { 185 do { 186 unsigned int dwaddress, dwords, offset; 187 u8 data[NVM_DATA_DWORDS * 4]; 188 size_t nbytes; 189 int ret; 190 191 offset = address & 3; 192 nbytes = min_t(size_t, size + offset, NVM_DATA_DWORDS * 4); 193 194 dwaddress = address / 4; 195 dwords = ALIGN(nbytes, 4) / 4; 196 197 ret = read_block(read_block_data, dwaddress, data, dwords); 198 if (ret) { 199 if (ret != -ENODEV && retries--) 200 continue; 201 return ret; 202 } 203 204 nbytes -= offset; 205 memcpy(buf, data + offset, nbytes); 206 207 size -= nbytes; 208 address += nbytes; 209 buf += nbytes; 210 } while (size > 0); 211 212 return 0; 213 } 214 215 /** 216 * tb_nvm_write_data() - Write data to NVM 217 * @address: Start address on the flash 218 * @buf: Buffer where the data is copied from 219 * @size: Size of the buffer in bytes 220 * @retries: Number of retries if the block write fails 221 * @write_block: Function that writes block to the flash 222 * @write_block_data: Data passwd to @write_block 223 * 224 * This is generic function that writes data to NVM or NVM like device. 225 * 226 * Returns %0 on success and negative errno otherwise. 227 */ 228 int tb_nvm_write_data(unsigned int address, const void *buf, size_t size, 229 unsigned int retries, write_block_fn write_block, 230 void *write_block_data) 231 { 232 do { 233 unsigned int offset, dwaddress; 234 u8 data[NVM_DATA_DWORDS * 4]; 235 size_t nbytes; 236 int ret; 237 238 offset = address & 3; 239 nbytes = min_t(u32, size + offset, NVM_DATA_DWORDS * 4); 240 241 memcpy(data + offset, buf, nbytes); 242 243 dwaddress = address / 4; 244 ret = write_block(write_block_data, dwaddress, data, nbytes / 4); 245 if (ret) { 246 if (ret == -ETIMEDOUT) { 247 if (retries--) 248 continue; 249 ret = -EIO; 250 } 251 return ret; 252 } 253 254 size -= nbytes; 255 address += nbytes; 256 buf += nbytes; 257 } while (size > 0); 258 259 return 0; 260 } 261 262 void tb_nvm_exit(void) 263 { 264 ida_destroy(&nvm_ida); 265 } 266