board: ge: make VPD code common
The VPD data is used on a number of GE products. Move the parsing code to
a common location so that we can share this code.
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Acked-by: Stefano Babic <sbabic@denx.de>
diff --git a/board/ge/common/Makefile b/board/ge/common/Makefile
new file mode 100644
index 0000000..93e6c01
--- /dev/null
+++ b/board/ge/common/Makefile
@@ -0,0 +1,7 @@
+#
+# Copyright 2017 General Electric Company
+#
+# SPDX-License-Identifier: GPL-2.0+
+#
+
+obj-y := vpd_reader.o
diff --git a/board/ge/common/vpd_reader.c b/board/ge/common/vpd_reader.c
new file mode 100644
index 0000000..7367427
--- /dev/null
+++ b/board/ge/common/vpd_reader.c
@@ -0,0 +1,197 @@
+/*
+ * Copyright 2016 General Electric Company
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include "vpd_reader.h"
+
+#include <linux/bch.h>
+#include <stdlib.h>
+
+/* BCH configuration */
+
+const struct {
+ int header_ecc_capability_bits;
+ int data_ecc_capability_bits;
+ unsigned int prim_poly;
+ struct {
+ int min;
+ int max;
+ } galois_field_order;
+} bch_configuration = {
+ .header_ecc_capability_bits = 4,
+ .data_ecc_capability_bits = 16,
+ .prim_poly = 0,
+ .galois_field_order = {
+ .min = 5,
+ .max = 15,
+ },
+};
+
+static int calculate_galois_field_order(size_t source_length)
+{
+ int gfo = bch_configuration.galois_field_order.min;
+
+ for (; gfo < bch_configuration.galois_field_order.max &&
+ ((((1 << gfo) - 1) - ((int)source_length * 8)) < 0);
+ gfo++) {
+ }
+
+ if (gfo == bch_configuration.galois_field_order.max)
+ return -1;
+
+ return gfo + 1;
+}
+
+static int verify_bch(int ecc_bits, unsigned int prim_poly, u8 *data,
+ size_t data_length, const u8 *ecc, size_t ecc_length)
+{
+ int gfo = calculate_galois_field_order(data_length);
+
+ if (gfo < 0)
+ return -1;
+
+ struct bch_control *bch = init_bch(gfo, ecc_bits, prim_poly);
+
+ if (!bch)
+ return -1;
+
+ if (bch->ecc_bytes != ecc_length) {
+ free_bch(bch);
+ return -1;
+ }
+
+ unsigned int *errloc = (unsigned int *)calloc(data_length,
+ sizeof(unsigned int));
+ int errors = decode_bch(bch, data, data_length, ecc, NULL, NULL,
+ errloc);
+
+ free_bch(bch);
+ if (errors < 0) {
+ free(errloc);
+ return -1;
+ }
+
+ if (errors > 0) {
+ for (int n = 0; n < errors; n++) {
+ if (errloc[n] >= 8 * data_length) {
+ /*
+ * n-th error located in ecc (no need for data
+ * correction)
+ */
+ } else {
+ /* n-th error located in data */
+ data[errloc[n] / 8] ^= 1 << (errloc[n] % 8);
+ }
+ }
+ }
+
+ free(errloc);
+ return 0;
+}
+
+static const int ID;
+static const int LEN = 1;
+static const int VER = 2;
+static const int TYP = 3;
+static const int BLOCK_SIZE = 4;
+
+static const u8 HEADER_BLOCK_ID;
+static const u8 HEADER_BLOCK_LEN = 18;
+static const u32 HEADER_BLOCK_MAGIC = 0xca53ca53;
+static const size_t HEADER_BLOCK_VERIFY_LEN = 14;
+static const size_t HEADER_BLOCK_ECC_OFF = 14;
+static const size_t HEADER_BLOCK_ECC_LEN = 4;
+
+static const u8 ECC_BLOCK_ID = 0xFF;
+
+int vpd_reader(size_t size, u8 *data, void *userdata,
+ int (*fn)(void *userdata, u8 id, u8 version, u8 type,
+ size_t size, u8 const *data))
+{
+ if (size < HEADER_BLOCK_LEN || !data || !fn)
+ return -EINVAL;
+
+ /*
+ * +--------------------+----------------+--//--+--------------------+
+ * | header block | data block | ... | ecc block |
+ * +--------------------+----------------+--//--+--------------------+
+ * : : :
+ * +------+-------+-----+ +------+-------------+
+ * | id | magic | ecc | | ... | ecc |
+ * | len | off | | +------+-------------+
+ * | ver | size | | :
+ * | type | | | :
+ * +------+-------+-----+ :
+ * : : : :
+ * <----- [1] ----> <--------- [2] --------->
+ *
+ * Repair (if necessary) the contents of header block [1] by using a
+ * 4 byte ECC located at the end of the header block. A successful
+ * return value means that we can trust the header.
+ */
+ int ret = verify_bch(bch_configuration.header_ecc_capability_bits,
+ bch_configuration.prim_poly, data,
+ HEADER_BLOCK_VERIFY_LEN,
+ &data[HEADER_BLOCK_ECC_OFF], HEADER_BLOCK_ECC_LEN);
+ if (ret < 0)
+ return ret;
+
+ /* Validate header block { id, length, version, type }. */
+ if (data[ID] != HEADER_BLOCK_ID || data[LEN] != HEADER_BLOCK_LEN ||
+ data[VER] != 0 || data[TYP] != 0 ||
+ ntohl(*(u32 *)(&data[4])) != HEADER_BLOCK_MAGIC)
+ return -EINVAL;
+
+ u32 offset = ntohl(*(u32 *)(&data[8]));
+ u16 size_bits = ntohs(*(u16 *)(&data[12]));
+
+ /* Check that ECC header fits. */
+ if (offset + 3 >= size)
+ return -EINVAL;
+
+ /* Validate ECC block. */
+ u8 *ecc = &data[offset];
+
+ if (ecc[ID] != ECC_BLOCK_ID || ecc[LEN] < BLOCK_SIZE ||
+ ecc[LEN] + offset > size ||
+ ecc[LEN] - BLOCK_SIZE != size_bits / 8 || ecc[VER] != 1 ||
+ ecc[TYP] != 1)
+ return -EINVAL;
+
+ /*
+ * Use the header block to locate the ECC block and verify the data
+ * blocks [2] against the ecc block ECC.
+ */
+ ret = verify_bch(bch_configuration.data_ecc_capability_bits,
+ bch_configuration.prim_poly, &data[data[LEN]],
+ offset - data[LEN], &data[offset + BLOCK_SIZE],
+ ecc[LEN] - BLOCK_SIZE);
+ if (ret < 0)
+ return ret;
+
+ /* Stop after ECC. Ignore possible zero padding. */
+ size = offset;
+
+ for (;;) {
+ /* Move to next block. */
+ size -= data[LEN];
+ data += data[LEN];
+
+ if (size == 0) {
+ /* Finished iterating through blocks. */
+ return 0;
+ }
+
+ if (size < BLOCK_SIZE || data[LEN] < BLOCK_SIZE) {
+ /* Not enough data for a header, or short header. */
+ return -EINVAL;
+ }
+
+ ret = fn(userdata, data[ID], data[VER], data[TYP],
+ data[LEN] - BLOCK_SIZE, &data[BLOCK_SIZE]);
+ if (ret)
+ return ret;
+ }
+}
diff --git a/board/ge/common/vpd_reader.h b/board/ge/common/vpd_reader.h
new file mode 100644
index 0000000..4abba8f
--- /dev/null
+++ b/board/ge/common/vpd_reader.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright 2016 General Electric Company
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include "common.h"
+
+/*
+ * Read VPD from given data, verify content, and call callback
+ * for each vital product data block.
+ *
+ * Returns Non-zero on error. Negative numbers encode errno.
+ */
+int vpd_reader(size_t size, u8 *data, void *userdata,
+ int (*fn)(void *userdata, u8 id, u8 version, u8 type,
+ size_t size, u8 const *data));