nvm.c
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// SPDX-License-Identifier: GPL-2.0
/*
* NVM helpers
*
* Copyright (C) 2020, Intel Corporation
* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
*/
#include <linux/idr.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include "tb.h"
static DEFINE_IDA(nvm_ida);
/**
* tb_nvm_alloc() - Allocate new NVM structure
* @dev: Device owning the NVM
*
* Allocates new NVM structure with unique @id and returns it. In case
* of error returns ERR_PTR().
*/
struct tb_nvm *tb_nvm_alloc(struct device *dev)
{
struct tb_nvm *nvm;
int ret;
nvm = kzalloc(sizeof(*nvm), GFP_KERNEL);
if (!nvm)
return ERR_PTR(-ENOMEM);
ret = ida_simple_get(&nvm_ida, 0, 0, GFP_KERNEL);
if (ret < 0) {
kfree(nvm);
return ERR_PTR(ret);
}
nvm->id = ret;
nvm->dev = dev;
return nvm;
}
/**
* tb_nvm_add_active() - Adds active NVMem device to NVM
* @nvm: NVM structure
* @size: Size of the active NVM in bytes
* @reg_read: Pointer to the function to read the NVM (passed directly to the
* NVMem device)
*
* Registers new active NVmem device for @nvm. The @reg_read is called
* directly from NVMem so it must handle possible concurrent access if
* needed. The first parameter passed to @reg_read is @nvm structure.
* Returns %0 in success and negative errno otherwise.
*/
int tb_nvm_add_active(struct tb_nvm *nvm, size_t size, nvmem_reg_read_t reg_read)
{
struct nvmem_config config;
struct nvmem_device *nvmem;
memset(&config, 0, sizeof(config));
config.name = "nvm_active";
config.reg_read = reg_read;
config.read_only = true;
config.id = nvm->id;
config.stride = 4;
config.word_size = 4;
config.size = size;
config.dev = nvm->dev;
config.owner = THIS_MODULE;
config.priv = nvm;
nvmem = nvmem_register(&config);
if (IS_ERR(nvmem))
return PTR_ERR(nvmem);
nvm->active = nvmem;
return 0;
}
/**
* tb_nvm_write_buf() - Write data to @nvm buffer
* @nvm: NVM structure
* @offset: Offset where to write the data
* @val: Data buffer to write
* @bytes: Number of bytes to write
*
* Helper function to cache the new NVM image before it is actually
* written to the flash. Copies @bytes from @val to @nvm->buf starting
* from @offset.
*/
int tb_nvm_write_buf(struct tb_nvm *nvm, unsigned int offset, void *val,
size_t bytes)
{
if (!nvm->buf) {
nvm->buf = vmalloc(NVM_MAX_SIZE);
if (!nvm->buf)
return -ENOMEM;
}
nvm->flushed = false;
nvm->buf_data_size = offset + bytes;
memcpy(nvm->buf + offset, val, bytes);
return 0;
}
/**
* tb_nvm_add_non_active() - Adds non-active NVMem device to NVM
* @nvm: NVM structure
* @size: Size of the non-active NVM in bytes
* @reg_write: Pointer to the function to write the NVM (passed directly
* to the NVMem device)
*
* Registers new non-active NVmem device for @nvm. The @reg_write is called
* directly from NVMem so it must handle possible concurrent access if
* needed. The first parameter passed to @reg_write is @nvm structure.
* Returns %0 in success and negative errno otherwise.
*/
int tb_nvm_add_non_active(struct tb_nvm *nvm, size_t size,
nvmem_reg_write_t reg_write)
{
struct nvmem_config config;
struct nvmem_device *nvmem;
memset(&config, 0, sizeof(config));
config.name = "nvm_non_active";
config.reg_write = reg_write;
config.root_only = true;
config.id = nvm->id;
config.stride = 4;
config.word_size = 4;
config.size = size;
config.dev = nvm->dev;
config.owner = THIS_MODULE;
config.priv = nvm;
nvmem = nvmem_register(&config);
if (IS_ERR(nvmem))
return PTR_ERR(nvmem);
nvm->non_active = nvmem;
return 0;
}
/**
* tb_nvm_free() - Release NVM and its resources
* @nvm: NVM structure to release
*
* Releases NVM and the NVMem devices if they were registered.
*/
void tb_nvm_free(struct tb_nvm *nvm)
{
if (nvm) {
if (nvm->non_active)
nvmem_unregister(nvm->non_active);
if (nvm->active)
nvmem_unregister(nvm->active);
vfree(nvm->buf);
ida_simple_remove(&nvm_ida, nvm->id);
}
kfree(nvm);
}
void tb_nvm_exit(void)
{
ida_destroy(&nvm_ida);
}