drivers/thunderbolt/nvm.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * NVM helpers
0004  *
0005  * Copyright (C) 2020, Intel Corporation
0006  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
0007  */
0008
0009 #include <linux/idr.h>
0010 #include <linux/slab.h>
0011 #include <linux/vmalloc.h>
0012
0013 #include "tb.h"
0014
0015 static DEFINE_IDA(nvm_ida);
0016
0017 /**
0018  * tb_nvm_alloc() - Allocate new NVM structure
0019  * @dev: Device owning the NVM
0020  *
0021  * Allocates new NVM structure with unique @id and returns it. In case
0022  * of error returns ERR_PTR().
0023  */
0024 struct tb_nvm *tb_nvm_alloc(struct device *dev)
0025 {
0026     struct tb_nvm *nvm;
0027     int ret;
0028
0029     nvm = kzalloc(sizeof(*nvm), GFP_KERNEL);
0030     if (!nvm)
0031         return ERR_PTR(-ENOMEM);
0032
0033     ret = ida_simple_get(&nvm_ida, 0, 0, GFP_KERNEL);
0034     if (ret < 0) {
0035         kfree(nvm);
0036         return ERR_PTR(ret);
0037     }
0038
0039     nvm->id = ret;
0040     nvm->dev = dev;
0041
0042     return nvm;
0043 }
0044
0045 /**
0046  * tb_nvm_add_active() - Adds active NVMem device to NVM
0047  * @nvm: NVM structure
0048  * @size: Size of the active NVM in bytes
0049  * @reg_read: Pointer to the function to read the NVM (passed directly to the
0050  *        NVMem device)
0051  *
0052  * Registers new active NVmem device for @nvm. The @reg_read is called
0053  * directly from NVMem so it must handle possible concurrent access if
0054  * needed. The first parameter passed to @reg_read is @nvm structure.
0055  * Returns %0 in success and negative errno otherwise.
0056  */
0057 int tb_nvm_add_active(struct tb_nvm *nvm, size_t size, nvmem_reg_read_t reg_read)
0058 {
0059     struct nvmem_config config;
0060     struct nvmem_device *nvmem;
0061
0062     memset(&config, 0, sizeof(config));
0063
0064     config.name = "nvm_active";
0065     config.reg_read = reg_read;
0066     config.read_only = true;
0067     config.id = nvm->id;
0068     config.stride = 4;
0069     config.word_size = 4;
0070     config.size = size;
0071     config.dev = nvm->dev;
0072     config.owner = THIS_MODULE;
0073     config.priv = nvm;
0074
0075     nvmem = nvmem_register(&config);
0076     if (IS_ERR(nvmem))
0077         return PTR_ERR(nvmem);
0078
0079     nvm->active = nvmem;
0080     return 0;
0081 }
0082
0083 /**
0084  * tb_nvm_write_buf() - Write data to @nvm buffer
0085  * @nvm: NVM structure
0086  * @offset: Offset where to write the data
0087  * @val: Data buffer to write
0088  * @bytes: Number of bytes to write
0089  *
0090  * Helper function to cache the new NVM image before it is actually
0091  * written to the flash. Copies @bytes from @val to @nvm->buf starting
0092  * from @offset.
0093  */
0094 int tb_nvm_write_buf(struct tb_nvm *nvm, unsigned int offset, void *val,
0095              size_t bytes)
0096 {
0097     if (!nvm->buf) {
0098         nvm->buf = vmalloc(NVM_MAX_SIZE);
0099         if (!nvm->buf)
0100             return -ENOMEM;
0101     }
0102
0103     nvm->flushed = false;
0104     nvm->buf_data_size = offset + bytes;
0105     memcpy(nvm->buf + offset, val, bytes);
0106     return 0;
0107 }
0108
0109 /**
0110  * tb_nvm_add_non_active() - Adds non-active NVMem device to NVM
0111  * @nvm: NVM structure
0112  * @size: Size of the non-active NVM in bytes
0113  * @reg_write: Pointer to the function to write the NVM (passed directly
0114  *         to the NVMem device)
0115  *
0116  * Registers new non-active NVmem device for @nvm. The @reg_write is called
0117  * directly from NVMem so it must handle possible concurrent access if
0118  * needed. The first parameter passed to @reg_write is @nvm structure.
0119  * Returns %0 in success and negative errno otherwise.
0120  */
0121 int tb_nvm_add_non_active(struct tb_nvm *nvm, size_t size,
0122               nvmem_reg_write_t reg_write)
0123 {
0124     struct nvmem_config config;
0125     struct nvmem_device *nvmem;
0126
0127     memset(&config, 0, sizeof(config));
0128
0129     config.name = "nvm_non_active";
0130     config.reg_write = reg_write;
0131     config.root_only = true;
0132     config.id = nvm->id;
0133     config.stride = 4;
0134     config.word_size = 4;
0135     config.size = size;
0136     config.dev = nvm->dev;
0137     config.owner = THIS_MODULE;
0138     config.priv = nvm;
0139
0140     nvmem = nvmem_register(&config);
0141     if (IS_ERR(nvmem))
0142         return PTR_ERR(nvmem);
0143
0144     nvm->non_active = nvmem;
0145     return 0;
0146 }
0147
0148 /**
0149  * tb_nvm_free() - Release NVM and its resources
0150  * @nvm: NVM structure to release
0151  *
0152  * Releases NVM and the NVMem devices if they were registered.
0153  */
0154 void tb_nvm_free(struct tb_nvm *nvm)
0155 {
0156     if (nvm) {
0157         nvmem_unregister(nvm->non_active);
0158         nvmem_unregister(nvm->active);
0159         vfree(nvm->buf);
0160         ida_simple_remove(&nvm_ida, nvm->id);
0161     }
0162     kfree(nvm);
0163 }
0164
0165 /**
0166  * tb_nvm_read_data() - Read data from NVM
0167  * @address: Start address on the flash
0168  * @buf: Buffer where the read data is copied
0169  * @size: Size of the buffer in bytes
0170  * @retries: Number of retries if block read fails
0171  * @read_block: Function that reads block from the flash
0172  * @read_block_data: Data passsed to @read_block
0173  *
0174  * This is a generic function that reads data from NVM or NVM like
0175  * device.
0176  *
0177  * Returns %0 on success and negative errno otherwise.
0178  */
0179 int tb_nvm_read_data(unsigned int address, void *buf, size_t size,
0180              unsigned int retries, read_block_fn read_block,
0181              void *read_block_data)
0182 {
0183     do {
0184         unsigned int dwaddress, dwords, offset;
0185         u8 data[NVM_DATA_DWORDS * 4];
0186         size_t nbytes;
0187         int ret;
0188
0189         offset = address & 3;
0190         nbytes = min_t(size_t, size + offset, NVM_DATA_DWORDS * 4);
0191
0192         dwaddress = address / 4;
0193         dwords = ALIGN(nbytes, 4) / 4;
0194
0195         ret = read_block(read_block_data, dwaddress, data, dwords);
0196         if (ret) {
0197             if (ret != -ENODEV && retries--)
0198                 continue;
0199             return ret;
0200         }
0201
0202         nbytes -= offset;
0203         memcpy(buf, data + offset, nbytes);
0204
0205         size -= nbytes;
0206         address += nbytes;
0207         buf += nbytes;
0208     } while (size > 0);
0209
0210     return 0;
0211 }
0212
0213 /**
0214  * tb_nvm_write_data() - Write data to NVM
0215  * @address: Start address on the flash
0216  * @buf: Buffer where the data is copied from
0217  * @size: Size of the buffer in bytes
0218  * @retries: Number of retries if the block write fails
0219  * @write_block: Function that writes block to the flash
0220  * @write_block_data: Data passwd to @write_block
0221  *
0222  * This is generic function that writes data to NVM or NVM like device.
0223  *
0224  * Returns %0 on success and negative errno otherwise.
0225  */
0226 int tb_nvm_write_data(unsigned int address, const void *buf, size_t size,
0227               unsigned int retries, write_block_fn write_block,
0228               void *write_block_data)
0229 {
0230     do {
0231         unsigned int offset, dwaddress;
0232         u8 data[NVM_DATA_DWORDS * 4];
0233         size_t nbytes;
0234         int ret;
0235
0236         offset = address & 3;
0237         nbytes = min_t(u32, size + offset, NVM_DATA_DWORDS * 4);
0238
0239         memcpy(data + offset, buf, nbytes);
0240
0241         dwaddress = address / 4;
0242         ret = write_block(write_block_data, dwaddress, data, nbytes / 4);
0243         if (ret) {
0244             if (ret == -ETIMEDOUT) {
0245                 if (retries--)
0246                     continue;
0247                 ret = -EIO;
0248             }
0249             return ret;
0250         }
0251
0252         size -= nbytes;
0253         address += nbytes;
0254         buf += nbytes;
0255     } while (size > 0);
0256
0257     return 0;
0258 }
0259
0260 void tb_nvm_exit(void)
0261 {
0262     ida_destroy(&nvm_ida);
0263 }