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https://github.com/AsahiLinux/u-boot
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4dcbccf794
Merge functionality duplicated in bx50v3 and mx53ppd: the logic is the same except that process_vpd is called at different phases. Also read_vpd could end up in error, so there is no VPD data in this case - it shouldn't be processed. Signed-off-by: Denis Zalevskiy <denis.zalevskiy@ge.com> Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.com>
227 lines
5.7 KiB
C
227 lines
5.7 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright 2016 General Electric Company
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*/
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#include "vpd_reader.h"
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#include <i2c.h>
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#include <linux/bch.h>
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#include <stdlib.h>
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/* BCH configuration */
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const struct {
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int header_ecc_capability_bits;
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int data_ecc_capability_bits;
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unsigned int prim_poly;
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struct {
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int min;
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int max;
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} galois_field_order;
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} bch_configuration = {
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.header_ecc_capability_bits = 4,
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.data_ecc_capability_bits = 16,
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.prim_poly = 0,
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.galois_field_order = {
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.min = 5,
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.max = 15,
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},
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};
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static int calculate_galois_field_order(size_t source_length)
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{
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int gfo = bch_configuration.galois_field_order.min;
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for (; gfo < bch_configuration.galois_field_order.max &&
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((((1 << gfo) - 1) - ((int)source_length * 8)) < 0);
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gfo++) {
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}
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if (gfo == bch_configuration.galois_field_order.max)
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return -1;
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return gfo + 1;
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}
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static int verify_bch(int ecc_bits, unsigned int prim_poly, u8 *data,
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size_t data_length, const u8 *ecc, size_t ecc_length)
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{
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int gfo = calculate_galois_field_order(data_length);
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if (gfo < 0)
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return -1;
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struct bch_control *bch = init_bch(gfo, ecc_bits, prim_poly);
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if (!bch)
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return -1;
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if (bch->ecc_bytes != ecc_length) {
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free_bch(bch);
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return -1;
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}
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unsigned int *errloc = (unsigned int *)calloc(data_length,
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sizeof(unsigned int));
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int errors = decode_bch(bch, data, data_length, ecc, NULL, NULL,
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errloc);
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free_bch(bch);
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if (errors < 0) {
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free(errloc);
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return -1;
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}
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if (errors > 0) {
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for (int n = 0; n < errors; n++) {
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if (errloc[n] >= 8 * data_length) {
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/*
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* n-th error located in ecc (no need for data
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* correction)
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*/
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} else {
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/* n-th error located in data */
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data[errloc[n] / 8] ^= 1 << (errloc[n] % 8);
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}
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}
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}
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free(errloc);
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return 0;
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}
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static const int ID;
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static const int LEN = 1;
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static const int VER = 2;
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static const int TYP = 3;
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static const int BLOCK_SIZE = 4;
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static const u8 HEADER_BLOCK_ID;
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static const u8 HEADER_BLOCK_LEN = 18;
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static const u32 HEADER_BLOCK_MAGIC = 0xca53ca53;
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static const size_t HEADER_BLOCK_VERIFY_LEN = 14;
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static const size_t HEADER_BLOCK_ECC_OFF = 14;
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static const size_t HEADER_BLOCK_ECC_LEN = 4;
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static const u8 ECC_BLOCK_ID = 0xFF;
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static int vpd_reader(size_t size, u8 *data, struct vpd_cache *userdata,
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int (*fn)(struct vpd_cache *, u8 id, u8 version, u8 type,
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size_t size, u8 const *data))
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{
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if (size < HEADER_BLOCK_LEN || !data || !fn)
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return -EINVAL;
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/*
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* +--------------------+----------------+--//--+--------------------+
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* | header block | data block | ... | ecc block |
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* +--------------------+----------------+--//--+--------------------+
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* : : :
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* +------+-------+-----+ +------+-------------+
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* | id | magic | ecc | | ... | ecc |
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* | len | off | | +------+-------------+
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* | ver | size | | :
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* | type | | | :
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* +------+-------+-----+ :
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* : : : :
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* <----- [1] ----> <--------- [2] --------->
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*
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* Repair (if necessary) the contents of header block [1] by using a
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* 4 byte ECC located at the end of the header block. A successful
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* return value means that we can trust the header.
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*/
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int ret = verify_bch(bch_configuration.header_ecc_capability_bits,
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bch_configuration.prim_poly, data,
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HEADER_BLOCK_VERIFY_LEN,
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&data[HEADER_BLOCK_ECC_OFF], HEADER_BLOCK_ECC_LEN);
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if (ret < 0)
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return ret;
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/* Validate header block { id, length, version, type }. */
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if (data[ID] != HEADER_BLOCK_ID || data[LEN] != HEADER_BLOCK_LEN ||
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data[VER] != 0 || data[TYP] != 0 ||
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ntohl(*(u32 *)(&data[4])) != HEADER_BLOCK_MAGIC)
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return -EINVAL;
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u32 offset = ntohl(*(u32 *)(&data[8]));
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u16 size_bits = ntohs(*(u16 *)(&data[12]));
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/* Check that ECC header fits. */
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if (offset + 3 >= size)
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return -EINVAL;
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/* Validate ECC block. */
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u8 *ecc = &data[offset];
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if (ecc[ID] != ECC_BLOCK_ID || ecc[LEN] < BLOCK_SIZE ||
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ecc[LEN] + offset > size ||
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ecc[LEN] - BLOCK_SIZE != size_bits / 8 || ecc[VER] != 1 ||
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ecc[TYP] != 1)
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return -EINVAL;
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/*
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* Use the header block to locate the ECC block and verify the data
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* blocks [2] against the ecc block ECC.
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*/
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ret = verify_bch(bch_configuration.data_ecc_capability_bits,
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bch_configuration.prim_poly, &data[data[LEN]],
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offset - data[LEN], &data[offset + BLOCK_SIZE],
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ecc[LEN] - BLOCK_SIZE);
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if (ret < 0)
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return ret;
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/* Stop after ECC. Ignore possible zero padding. */
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size = offset;
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for (;;) {
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/* Move to next block. */
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size -= data[LEN];
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data += data[LEN];
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if (size == 0) {
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/* Finished iterating through blocks. */
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return 0;
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}
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if (size < BLOCK_SIZE || data[LEN] < BLOCK_SIZE) {
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/* Not enough data for a header, or short header. */
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return -EINVAL;
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}
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ret = fn(userdata, data[ID], data[VER], data[TYP],
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data[LEN] - BLOCK_SIZE, &data[BLOCK_SIZE]);
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if (ret)
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return ret;
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}
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}
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int read_vpd(struct vpd_cache *cache,
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int (*process_block)(struct vpd_cache *, u8 id, u8 version,
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u8 type, size_t size, u8 const *data))
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{
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static const size_t size = CONFIG_SYS_VPD_EEPROM_SIZE;
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int res;
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u8 *data;
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unsigned int current_i2c_bus = i2c_get_bus_num();
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res = i2c_set_bus_num(CONFIG_SYS_VPD_EEPROM_I2C_BUS);
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if (res < 0)
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return res;
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data = malloc(size);
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if (!data)
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return -ENOMEM;
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res = i2c_read(CONFIG_SYS_VPD_EEPROM_I2C_ADDR, 0,
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CONFIG_SYS_VPD_EEPROM_I2C_ADDR_LEN,
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data, size);
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if (res == 0)
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res = vpd_reader(size, data, cache, process_block);
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free(data);
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i2c_set_bus_num(current_i2c_bus);
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return res;
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}
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