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/*
* Copyright (C) 2016 Pengutronix, Markus Pargmann <mpa@pengutronix.de>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/string.h>
#include <malloc.h>
#include <printk.h>
#include "state.h"
/**
* Save the state
* @param state
* @return
*/
int state_save(struct state *state)
{
uint8_t *buf;
ssize_t len;
int ret;
struct state_backend *backend = &state->backend;
if (!state->dirty)
return 0;
ret = backend->format->pack(backend->format, state, &buf, &len);
if (ret) {
dev_err(&state->dev, "Failed to pack state with backend format %s, %d\n",
backend->format->name, ret);
return ret;
}
ret = state_storage_write(&backend->storage, buf, len);
if (ret) {
dev_err(&state->dev, "Failed to write packed state, %d\n", ret);
goto out;
}
state->dirty = 0;
out:
free(buf);
return ret;
}
/**
* state_load - Loads a state from the backend
* @param state The state that should be updated to contain the loaded data
* @return 0 on success, -errno on failure. If no state is loaded the previous
* values remain in the state.
*
* This function uses the registered storage backend to read data. All data that
* we read is checked for integrity by the formatter. After that we unpack the
* data into our state.
*/
int state_load(struct state *state)
{
uint8_t *buf;
ssize_t len;
ssize_t len_hint = 0;
int ret;
struct state_backend *backend = &state->backend;
if (backend->format->get_packed_len)
len_hint = backend->format->get_packed_len(backend->format,
state);
ret = state_storage_read(&backend->storage, backend->format,
state->magic, &buf, &len, len_hint);
if (ret) {
dev_err(&state->dev, "Failed to read state with format %s, %d\n",
backend->format->name, ret);
return ret;
}
ret = backend->format->unpack(backend->format, state, buf, len);
if (ret) {
dev_err(&state->dev, "Failed to unpack read data with format %s although verified, %d\n",
backend->format->name, ret);
goto out;
}
state->dirty = 0;
out:
free(buf);
return ret;
}
static int state_format_init(struct state_backend *backend,
struct device_d *dev, const char *backend_format,
struct device_node *node, const char *state_name)
{
int ret;
if (!strcmp(backend_format, "raw")) {
ret = backend_format_raw_create(&backend->format, node,
state_name, dev);
} else if (!strcmp(backend_format, "dtb")) {
ret = backend_format_dtb_create(&backend->format, dev);
} else {
dev_err(dev, "Invalid backend format %s\n",
backend_format);
return -EINVAL;
}
if (ret && ret != -EPROBE_DEFER)
dev_err(dev, "Failed to initialize format %s, %d\n",
backend_format, ret);
return ret;
}
static void state_format_free(struct state_backend_format *format)
{
if (format->free)
format->free(format);
}
/**
* state_backend_init - Initiates the backend storage and format using the
* passed arguments
* @param backend state backend
* @param dev Device pointer used for prints
* @param node the DT device node corresponding to the state
* @param backend_format a string describing the format. Valid values are 'raw'
* and 'dtb' currently
* @param storage_path Path to the backend storage file/device/partition/...
* @param state_name Name of the state
* @param of_path Path in the devicetree
* @param stridesize stridesize in case we have a medium without eraseblocks.
* stridesize describes how far apart copies of the same data should be stored.
* For blockdevices it makes sense to align them on blocksize.
* @param storagetype Type of the storage backend. This may be NULL where we
* autoselect some backwardscompatible backend options
* @return 0 on success, -errno otherwise
*/
int state_backend_init(struct state_backend *backend, struct device_d *dev,
struct device_node *node, const char *backend_format,
const char *storage_path, const char *state_name, const
char *of_path, off_t offset, size_t max_size,
uint32_t stridesize, const char *storagetype)
{
int ret;
ret = state_format_init(backend, dev, backend_format, node, state_name);
if (ret)
return ret;
ret = state_storage_init(&backend->storage, dev, storage_path, offset,
max_size, stridesize, storagetype);
if (ret)
goto out_free_format;
backend->of_path = xstrdup(of_path);
return 0;
out_free_format:
state_format_free(backend->format);
backend->format = NULL;
return ret;
}
void state_backend_set_readonly(struct state_backend *backend)
{
state_storage_set_readonly(&backend->storage);
}
void state_backend_free(struct state_backend *backend)
{
state_storage_free(&backend->storage);
if (backend->format)
state_format_free(backend->format);
free(backend->of_path);
}
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