[PATCH 1/8] bch: update from Kernel
Sascha Hauer
s.hauer at pengutronix.de
Tue Apr 16 02:53:06 PDT 2024
This updates BCH support from Linux as of Linux-6.9-rc2. Among other
things in Linux the bch function names changed from a _bch suffix to a bch_
prefix.
Link: https://lore.barebox.org/20240416062147.1337233-1-s.hauer@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
common/imx-bbu-nand-fcb.c | 12 +--
drivers/mtd/devices/docg3.c | 8 +-
drivers/mtd/nand/nand_bch.c | 10 +--
include/linux/bch.h | 25 ++----
lib/Kconfig | 1 +
lib/bch.c | 167 +++++++++++++++++++++++-------------
6 files changed, 130 insertions(+), 93 deletions(-)
diff --git a/common/imx-bbu-nand-fcb.c b/common/imx-bbu-nand-fcb.c
index 0d46192720..d0261140cf 100644
--- a/common/imx-bbu-nand-fcb.c
+++ b/common/imx-bbu-nand-fcb.c
@@ -79,7 +79,7 @@ static void encode_bch_ecc(void *buf, struct fcb_block *fcb, int eccbits)
int blocksize = 128;
int numblocks = 8;
int ecc_buf_size = (m * eccbits + 7) / 8;
- struct bch_control *bch = init_bch(m, eccbits, 0);
+ struct bch_control *bch = bch_init(m, eccbits, 0, false);
uint8_t *ecc_buf = xmalloc(ecc_buf_size);
uint8_t *tmp_buf = xzalloc(blocksize * numblocks);
uint8_t *psrc, *pdst;
@@ -109,7 +109,7 @@ static void encode_bch_ecc(void *buf, struct fcb_block *fcb, int eccbits)
for (j = 0; j < blocksize; j++)
psrc[j] = reverse_bit(psrc[j]);
- encode_bch(bch, psrc, blocksize, ecc_buf);
+ bch_encode(bch, psrc, blocksize, ecc_buf);
/* reverse ecc bit */
for (j = 0; j < ecc_buf_size; j++)
@@ -121,7 +121,7 @@ static void encode_bch_ecc(void *buf, struct fcb_block *fcb, int eccbits)
free(ecc_buf);
free(tmp_buf);
- free_bch(bch);
+ bch_free(bch);
}
static struct fcb_block *fcb_decode_bch(void *rawpage, int eccbits)
@@ -130,7 +130,7 @@ static struct fcb_block *fcb_decode_bch(void *rawpage, int eccbits)
int blocksize = 128;
int numblocks = 8;
int ecc_buf_size = (m * eccbits + 7) / 8;
- struct bch_control *bch = init_bch(m, eccbits, 0);
+ struct bch_control *bch = bch_init(m, eccbits, 0, false);
uint8_t *fcb = xmalloc(numblocks * blocksize);
uint8_t *ecc_buf = xmalloc(ecc_buf_size);
uint8_t *data_buf = xmalloc(blocksize);
@@ -152,7 +152,7 @@ static struct fcb_block *fcb_decode_bch(void *rawpage, int eccbits)
for (j = 0; j < ecc_buf_size; j++)
ecc_buf[j] = reverse_bit(psrc[j + blocksize]);
- ret = decode_bch(bch, data_buf, blocksize, ecc_buf,
+ ret = bch_decode(bch, data_buf, blocksize, ecc_buf,
NULL, NULL, errloc);
if (ret < 0) {
@@ -185,7 +185,7 @@ static struct fcb_block *fcb_decode_bch(void *rawpage, int eccbits)
free(data_buf);
free(ecc_buf);
free(errloc);
- free_bch(bch);
+ bch_free(bch);
return (struct fcb_block *)fcb;
}
diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
index 593a7035e5..fcf9403b8f 100644
--- a/drivers/mtd/devices/docg3.c
+++ b/drivers/mtd/devices/docg3.c
@@ -325,7 +325,7 @@ static int doc_ecc_bch_fix_data(struct docg3 *docg3, void *buf, u8 *hwecc)
for (i = 0; i < DOC_ECC_BCH_SIZE; i++)
ecc[i] = bitrev8(hwecc[i]);
- numerrs = decode_bch(docg3_bch, NULL, DOC_ECC_BCH_COVERED_BYTES,
+ numerrs = bch_decode(docg3_bch, NULL, DOC_ECC_BCH_COVERED_BYTES,
NULL, ecc, NULL, errorpos);
BUG_ON(numerrs == -EINVAL);
if (numerrs < 0)
@@ -1144,8 +1144,8 @@ static int __init docg3_probe(struct device *dev)
base = IOMEM(iores->start);
ret = -ENOMEM;
- docg3_bch = init_bch(DOC_ECC_BCH_M, DOC_ECC_BCH_T,
- DOC_ECC_BCH_PRIMPOLY);
+ docg3_bch = bch_init(DOC_ECC_BCH_M, DOC_ECC_BCH_T,
+ DOC_ECC_BCH_PRIMPOLY, false);
if (!docg3_bch)
goto nomem2;
@@ -1181,7 +1181,7 @@ static int __init docg3_probe(struct device *dev)
ret = -ENODEV;
dev_info(dev, "No supported DiskOnChip found\n");
err_probe:
- free_bch(docg3_bch);
+ bch_free(docg3_bch);
nomem2:
return ret;
}
diff --git a/drivers/mtd/nand/nand_bch.c b/drivers/mtd/nand/nand_bch.c
index 0d636d9608..45f9c5052a 100644
--- a/drivers/mtd/nand/nand_bch.c
+++ b/drivers/mtd/nand/nand_bch.c
@@ -42,7 +42,7 @@ int nand_bch_calculate_ecc(struct nand_chip *chip, const unsigned char *buf,
unsigned int i;
memset(code, 0, chip->ecc.bytes);
- encode_bch(nbc->bch, buf, chip->ecc.size, code);
+ bch_encode(nbc->bch, buf, chip->ecc.size, code);
/* apply mask so that an erased page is a valid codeword */
for (i = 0; i < chip->ecc.bytes; i++)
@@ -68,7 +68,7 @@ int nand_bch_correct_data(struct nand_chip *chip, unsigned char *buf,
unsigned int *errloc = nbc->errloc;
int i, count;
- count = decode_bch(nbc->bch, NULL, chip->ecc.size, read_ecc, calc_ecc,
+ count = bch_decode(nbc->bch, NULL, chip->ecc.size, read_ecc, calc_ecc,
NULL, errloc);
if (count > 0) {
for (i = 0; i < count; i++) {
@@ -131,7 +131,7 @@ struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
if (!nbc)
goto fail;
- nbc->bch = init_bch(m, t, 0);
+ nbc->bch = bch_init(m, t, 0, false);
if (!nbc->bch)
goto fail;
@@ -183,7 +183,7 @@ struct nand_bch_control *nand_bch_init(struct mtd_info *mtd)
goto fail;
memset(erased_page, 0xff, eccsize);
- encode_bch(nbc->bch, erased_page, eccsize, nbc->eccmask);
+ bch_encode(nbc->bch, erased_page, eccsize, nbc->eccmask);
kfree(erased_page);
for (i = 0; i < eccbytes; i++)
@@ -206,7 +206,7 @@ EXPORT_SYMBOL(nand_bch_init);
void nand_bch_free(struct nand_bch_control *nbc)
{
if (nbc) {
- free_bch(nbc->bch);
+ bch_free(nbc->bch);
kfree(nbc->errloc);
kfree(nbc->eccmask);
kfree(nbc);
diff --git a/include/linux/bch.h b/include/linux/bch.h
index 295b4ef153..85fdce83d4 100644
--- a/include/linux/bch.h
+++ b/include/linux/bch.h
@@ -1,19 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Generic binary BCH encoding/decoding library
*
- * 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.
- *
- * You should have received a copy of the GNU General Public License along with
- * this program; if not, write to the Free Software Foundation, Inc., 51
- * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
* Copyright © 2011 Parrot S.A.
*
* Author: Ivan Djelic <ivan.djelic at parrot.com>
@@ -45,6 +33,7 @@
* @cache: log-based polynomial representation buffer
* @elp: error locator polynomial
* @poly_2t: temporary polynomials of degree 2t
+ * @swap_bits: swap bits within data and syndrome bytes
*/
struct bch_control {
unsigned int m;
@@ -63,16 +52,18 @@ struct bch_control {
int *cache;
struct gf_poly *elp;
struct gf_poly *poly_2t[4];
+ bool swap_bits;
};
-struct bch_control *init_bch(int m, int t, unsigned int prim_poly);
+struct bch_control *bch_init(int m, int t, unsigned int prim_poly,
+ bool swap_bits);
-void free_bch(struct bch_control *bch);
+void bch_free(struct bch_control *bch);
-void encode_bch(struct bch_control *bch, const uint8_t *data,
+void bch_encode(struct bch_control *bch, const uint8_t *data,
unsigned int len, uint8_t *ecc);
-int decode_bch(struct bch_control *bch, const uint8_t *data, unsigned int len,
+int bch_decode(struct bch_control *bch, const uint8_t *data, unsigned int len,
const uint8_t *recv_ecc, const uint8_t *calc_ecc,
const unsigned int *syn, unsigned int *errloc);
diff --git a/lib/Kconfig b/lib/Kconfig
index 71715ef6e8..df9ba6ccc9 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -86,6 +86,7 @@ config BCH_CONST_PARAMS
bool
config BCH
+ select BITREV
bool
config BITREV
diff --git a/lib/bch.c b/lib/bch.c
index 5797c3faf8..c4e59eaf37 100644
--- a/lib/bch.c
+++ b/lib/bch.c
@@ -10,6 +10,10 @@
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
* Copyright © 2011 Parrot S.A.
*
* Author: Ivan Djelic <ivan.djelic at parrot.com>
@@ -19,15 +23,15 @@
* This library provides runtime configurable encoding/decoding of binary
* Bose-Chaudhuri-Hocquenghem (BCH) codes.
*
- * Call init_bch to get a pointer to a newly allocated bch_control structure for
+ * Call bch_init to get a pointer to a newly allocated bch_control structure for
* the given m (Galois field order), t (error correction capability) and
* (optional) primitive polynomial parameters.
*
- * Call encode_bch to compute and store ecc parity bytes to a given buffer.
- * Call decode_bch to detect and locate errors in received data.
+ * Call bch_encode to compute and store ecc parity bytes to a given buffer.
+ * Call bch_decode to detect and locate errors in received data.
*
* On systems supporting hw BCH features, intermediate results may be provided
- * to decode_bch in order to skip certain steps. See decode_bch() documentation
+ * to bch_decode in order to skip certain steps. See bch_decode() documentation
* for details.
*
* Option CONFIG_BCH_CONST_PARAMS can be used to force fixed values of
@@ -59,16 +63,14 @@
* - WEWoRC 2009, Graz, Austria, LNCS, Springer, July 2009, to appear.
* [2] [Zin96] V.A. Zinoviev. On the solution of equations of degree 10 over
* finite fields GF(2^q). In Rapport de recherche INRIA no 2829, 1996.
- *
- * Taken from the linux kernel.
*/
-#include <common.h>
-#include <errno.h>
-#include <init.h>
-#include <malloc.h>
#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
#include <linux/bitops.h>
+#include <linux/bitrev.h>
#include <asm/byteorder.h>
#include <linux/bch.h>
@@ -76,15 +78,21 @@
#define GF_M(_p) (CONFIG_BCH_CONST_M)
#define GF_T(_p) (CONFIG_BCH_CONST_T)
#define GF_N(_p) ((1 << (CONFIG_BCH_CONST_M))-1)
+#define BCH_MAX_M (CONFIG_BCH_CONST_M)
+#define BCH_MAX_T (CONFIG_BCH_CONST_T)
#else
#define GF_M(_p) ((_p)->m)
#define GF_T(_p) ((_p)->t)
#define GF_N(_p) ((_p)->n)
+#define BCH_MAX_M 15 /* 2KB */
+#define BCH_MAX_T 64 /* 64 bit correction */
#endif
#define BCH_ECC_WORDS(_p) DIV_ROUND_UP(GF_M(_p)*GF_T(_p), 32)
#define BCH_ECC_BYTES(_p) DIV_ROUND_UP(GF_M(_p)*GF_T(_p), 8)
+#define BCH_ECC_MAX_WORDS DIV_ROUND_UP(BCH_MAX_M * BCH_MAX_T, 32)
+
#ifndef dbg
#define dbg(_fmt, args...) do {} while (0)
#endif
@@ -94,7 +102,7 @@
*/
struct gf_poly {
unsigned int deg; /* polynomial degree */
- unsigned int c[0]; /* polynomial terms */
+ unsigned int c[]; /* polynomial terms */
};
/* given its degree, compute a polynomial size in bytes */
@@ -106,10 +114,18 @@ struct gf_poly_deg1 {
unsigned int c[2];
};
+static u8 swap_bits(struct bch_control *bch, u8 in)
+{
+ if (!bch->swap_bits)
+ return in;
+
+ return bitrev8(in);
+}
+
/*
- * same as encode_bch(), but process input data one byte at a time
+ * same as bch_encode(), but process input data one byte at a time
*/
-static void encode_bch_unaligned(struct bch_control *bch,
+static void bch_encode_unaligned(struct bch_control *bch,
const unsigned char *data, unsigned int len,
uint32_t *ecc)
{
@@ -118,7 +134,9 @@ static void encode_bch_unaligned(struct bch_control *bch,
const int l = BCH_ECC_WORDS(bch)-1;
while (len--) {
- p = bch->mod8_tab + (l+1)*(((ecc[0] >> 24)^(*data++)) & 0xff);
+ u8 tmp = swap_bits(bch, *data++);
+
+ p = bch->mod8_tab + (l+1)*(((ecc[0] >> 24)^(tmp)) & 0xff);
for (i = 0; i < l; i++)
ecc[i] = ((ecc[i] << 8)|(ecc[i+1] >> 24))^(*p++);
@@ -137,10 +155,16 @@ static void load_ecc8(struct bch_control *bch, uint32_t *dst,
unsigned int i, nwords = BCH_ECC_WORDS(bch)-1;
for (i = 0; i < nwords; i++, src += 4)
- dst[i] = (src[0] << 24)|(src[1] << 16)|(src[2] << 8)|src[3];
+ dst[i] = ((u32)swap_bits(bch, src[0]) << 24) |
+ ((u32)swap_bits(bch, src[1]) << 16) |
+ ((u32)swap_bits(bch, src[2]) << 8) |
+ swap_bits(bch, src[3]);
memcpy(pad, src, BCH_ECC_BYTES(bch)-4*nwords);
- dst[nwords] = (pad[0] << 24)|(pad[1] << 16)|(pad[2] << 8)|pad[3];
+ dst[nwords] = ((u32)swap_bits(bch, pad[0]) << 24) |
+ ((u32)swap_bits(bch, pad[1]) << 16) |
+ ((u32)swap_bits(bch, pad[2]) << 8) |
+ swap_bits(bch, pad[3]);
}
/*
@@ -153,20 +177,20 @@ static void store_ecc8(struct bch_control *bch, uint8_t *dst,
unsigned int i, nwords = BCH_ECC_WORDS(bch)-1;
for (i = 0; i < nwords; i++) {
- *dst++ = (src[i] >> 24);
- *dst++ = (src[i] >> 16) & 0xff;
- *dst++ = (src[i] >> 8) & 0xff;
- *dst++ = (src[i] >> 0) & 0xff;
+ *dst++ = swap_bits(bch, src[i] >> 24);
+ *dst++ = swap_bits(bch, src[i] >> 16);
+ *dst++ = swap_bits(bch, src[i] >> 8);
+ *dst++ = swap_bits(bch, src[i]);
}
- pad[0] = (src[nwords] >> 24);
- pad[1] = (src[nwords] >> 16) & 0xff;
- pad[2] = (src[nwords] >> 8) & 0xff;
- pad[3] = (src[nwords] >> 0) & 0xff;
+ pad[0] = swap_bits(bch, src[nwords] >> 24);
+ pad[1] = swap_bits(bch, src[nwords] >> 16);
+ pad[2] = swap_bits(bch, src[nwords] >> 8);
+ pad[3] = swap_bits(bch, src[nwords]);
memcpy(dst, pad, BCH_ECC_BYTES(bch)-4*nwords);
}
/**
- * encode_bch - calculate BCH ecc parity of data
+ * bch_encode - calculate BCH ecc parity of data
* @bch: BCH control structure
* @data: data to encode
* @len: data length in bytes
@@ -179,31 +203,35 @@ static void store_ecc8(struct bch_control *bch, uint8_t *dst,
* The exact number of computed ecc parity bits is given by member @ecc_bits of
* @bch; it may be less than m*t for large values of t.
*/
-void encode_bch(struct bch_control *bch, const uint8_t *data,
+void bch_encode(struct bch_control *bch, const uint8_t *data,
unsigned int len, uint8_t *ecc)
{
const unsigned int l = BCH_ECC_WORDS(bch)-1;
unsigned int i, mlen;
unsigned long m;
- uint32_t w, r[l+1];
+ uint32_t w, r[BCH_ECC_MAX_WORDS];
+ const size_t r_bytes = BCH_ECC_WORDS(bch) * sizeof(*r);
const uint32_t * const tab0 = bch->mod8_tab;
const uint32_t * const tab1 = tab0 + 256*(l+1);
const uint32_t * const tab2 = tab1 + 256*(l+1);
const uint32_t * const tab3 = tab2 + 256*(l+1);
const uint32_t *pdata, *p0, *p1, *p2, *p3;
+ if (WARN_ON(r_bytes > sizeof(r)))
+ return;
+
if (ecc) {
/* load ecc parity bytes into internal 32-bit buffer */
load_ecc8(bch, bch->ecc_buf, ecc);
} else {
- memset(bch->ecc_buf, 0, sizeof(r));
+ memset(bch->ecc_buf, 0, r_bytes);
}
/* process first unaligned data bytes */
m = ((unsigned long)data) & 3;
if (m) {
mlen = (len < (4-m)) ? len : 4-m;
- encode_bch_unaligned(bch, data, mlen, bch->ecc_buf);
+ bch_encode_unaligned(bch, data, mlen, bch->ecc_buf);
data += mlen;
len -= mlen;
}
@@ -213,7 +241,7 @@ void encode_bch(struct bch_control *bch, const uint8_t *data,
mlen = len/4;
data += 4*mlen;
len -= 4*mlen;
- memcpy(r, bch->ecc_buf, sizeof(r));
+ memcpy(r, bch->ecc_buf, r_bytes);
/*
* split each 32-bit word into 4 polynomials of weight 8 as follows:
@@ -228,7 +256,13 @@ void encode_bch(struct bch_control *bch, const uint8_t *data,
*/
while (mlen--) {
/* input data is read in big-endian format */
- w = r[0]^cpu_to_be32(*pdata++);
+ w = cpu_to_be32(*pdata++);
+ if (bch->swap_bits)
+ w = (u32)swap_bits(bch, w) |
+ ((u32)swap_bits(bch, w >> 8) << 8) |
+ ((u32)swap_bits(bch, w >> 16) << 16) |
+ ((u32)swap_bits(bch, w >> 24) << 24);
+ w ^= r[0];
p0 = tab0 + (l+1)*((w >> 0) & 0xff);
p1 = tab1 + (l+1)*((w >> 8) & 0xff);
p2 = tab2 + (l+1)*((w >> 16) & 0xff);
@@ -239,17 +273,17 @@ void encode_bch(struct bch_control *bch, const uint8_t *data,
r[l] = p0[l]^p1[l]^p2[l]^p3[l];
}
- memcpy(bch->ecc_buf, r, sizeof(r));
+ memcpy(bch->ecc_buf, r, r_bytes);
/* process last unaligned bytes */
if (len)
- encode_bch_unaligned(bch, data, len, bch->ecc_buf);
+ bch_encode_unaligned(bch, data, len, bch->ecc_buf);
/* store ecc parity bytes into original parity buffer */
if (ecc)
store_ecc8(bch, ecc, bch->ecc_buf);
}
-EXPORT_SYMBOL_GPL(encode_bch);
+EXPORT_SYMBOL_GPL(bch_encode);
static inline int modulo(struct bch_control *bch, unsigned int v)
{
@@ -432,7 +466,7 @@ static int solve_linear_system(struct bch_control *bch, unsigned int *rows,
{
const int m = GF_M(bch);
unsigned int tmp, mask;
- int rem, c, r, p, k, param[m];
+ int rem, c, r, p, k, param[BCH_MAX_M];
k = 0;
mask = 1 << m;
@@ -515,7 +549,7 @@ static int find_affine4_roots(struct bch_control *bch, unsigned int a,
k = a_log(bch, a);
rows[0] = c;
- /* buid linear system to solve X^4+aX^2+bX+c = 0 */
+ /* build linear system to solve X^4+aX^2+bX+c = 0 */
for (i = 0; i < m; i++) {
rows[i+1] = bch->a_pow_tab[4*i]^
(a ? bch->a_pow_tab[mod_s(bch, k)] : 0)^
@@ -940,7 +974,7 @@ static int chien_search(struct bch_control *bch, unsigned int len,
#endif /* USE_CHIEN_SEARCH */
/**
- * decode_bch - decode received codeword and find bit error locations
+ * bch_decode - decode received codeword and find bit error locations
* @bch: BCH control structure
* @data: received data, ignored if @calc_ecc is provided
* @len: data length in bytes, must always be provided
@@ -954,22 +988,22 @@ static int chien_search(struct bch_control *bch, unsigned int len,
* invalid parameters were provided
*
* Depending on the available hw BCH support and the need to compute @calc_ecc
- * separately (using encode_bch()), this function should be called with one of
+ * separately (using bch_encode()), this function should be called with one of
* the following parameter configurations -
*
* by providing @data and @recv_ecc only:
- * decode_bch(@bch, @data, @len, @recv_ecc, NULL, NULL, @errloc)
+ * bch_decode(@bch, @data, @len, @recv_ecc, NULL, NULL, @errloc)
*
* by providing @recv_ecc and @calc_ecc:
- * decode_bch(@bch, NULL, @len, @recv_ecc, @calc_ecc, NULL, @errloc)
+ * bch_decode(@bch, NULL, @len, @recv_ecc, @calc_ecc, NULL, @errloc)
*
* by providing ecc = recv_ecc XOR calc_ecc:
- * decode_bch(@bch, NULL, @len, NULL, ecc, NULL, @errloc)
+ * bch_decode(@bch, NULL, @len, NULL, ecc, NULL, @errloc)
*
* by providing syndrome results @syn:
- * decode_bch(@bch, NULL, @len, NULL, NULL, @syn, @errloc)
+ * bch_decode(@bch, NULL, @len, NULL, NULL, @syn, @errloc)
*
- * Once decode_bch() has successfully returned with a positive value, error
+ * Once bch_decode() has successfully returned with a positive value, error
* locations returned in array @errloc should be interpreted as follows -
*
* if (errloc[n] >= 8*len), then n-th error is located in ecc (no need for
@@ -981,7 +1015,7 @@ static int chien_search(struct bch_control *bch, unsigned int len,
* Note that this function does not perform any data correction by itself, it
* merely indicates error locations.
*/
-int decode_bch(struct bch_control *bch, const uint8_t *data, unsigned int len,
+int bch_decode(struct bch_control *bch, const uint8_t *data, unsigned int len,
const uint8_t *recv_ecc, const uint8_t *calc_ecc,
const unsigned int *syn, unsigned int *errloc)
{
@@ -1000,7 +1034,7 @@ int decode_bch(struct bch_control *bch, const uint8_t *data, unsigned int len,
/* compute received data ecc into an internal buffer */
if (!data || !recv_ecc)
return -EINVAL;
- encode_bch(bch, data, len, NULL);
+ bch_encode(bch, data, len, NULL);
} else {
/* load provided calculated ecc */
load_ecc8(bch, bch->ecc_buf, calc_ecc);
@@ -1036,12 +1070,14 @@ int decode_bch(struct bch_control *bch, const uint8_t *data, unsigned int len,
break;
}
errloc[i] = nbits-1-errloc[i];
- errloc[i] = (errloc[i] & ~7)|(7-(errloc[i] & 7));
+ if (!bch->swap_bits)
+ errloc[i] = (errloc[i] & ~7) |
+ (7-(errloc[i] & 7));
}
}
return (err >= 0) ? err : -EBADMSG;
}
-EXPORT_SYMBOL_GPL(decode_bch);
+EXPORT_SYMBOL_GPL(bch_decode);
/*
* generate Galois field lookup tables
@@ -1112,7 +1148,7 @@ static int build_deg2_base(struct bch_control *bch)
{
const int m = GF_M(bch);
int i, j, r;
- unsigned int sum, x, y, remaining, ak = 0, xi[m];
+ unsigned int sum, x, y, remaining, ak = 0, xi[BCH_MAX_M];
/* find k s.t. Tr(a^k) = 1 and 0 <= k < m */
for (i = 0; i < m; i++) {
@@ -1224,27 +1260,29 @@ static uint32_t *compute_generator_polynomial(struct bch_control *bch)
}
/**
- * init_bch - initialize a BCH encoder/decoder
+ * bch_init - initialize a BCH encoder/decoder
* @m: Galois field order, should be in the range 5-15
* @t: maximum error correction capability, in bits
* @prim_poly: user-provided primitive polynomial (or 0 to use default)
+ * @swap_bits: swap bits within data and syndrome bytes
*
* Returns:
* a newly allocated BCH control structure if successful, NULL otherwise
*
* This initialization can take some time, as lookup tables are built for fast
* encoding/decoding; make sure not to call this function from a time critical
- * path. Usually, init_bch() should be called on module/driver init and
- * free_bch() should be called to release memory on exit.
+ * path. Usually, bch_init() should be called on module/driver init and
+ * bch_free() should be called to release memory on exit.
*
* You may provide your own primitive polynomial of degree @m in argument
- * @prim_poly, or let init_bch() use its default polynomial.
+ * @prim_poly, or let bch_init() use its default polynomial.
*
- * Once init_bch() has successfully returned a pointer to a newly allocated
+ * Once bch_init() has successfully returned a pointer to a newly allocated
* BCH control structure, ecc length in bytes is given by member @ecc_bytes of
* the structure.
*/
-struct bch_control *init_bch(int m, int t, unsigned int prim_poly)
+struct bch_control *bch_init(int m, int t, unsigned int prim_poly,
+ bool swap_bits)
{
int err = 0;
unsigned int i, words;
@@ -1252,7 +1290,6 @@ struct bch_control *init_bch(int m, int t, unsigned int prim_poly)
struct bch_control *bch = NULL;
const int min_m = 5;
- const int max_m = 15;
/* default primitive polynomials */
static const unsigned int prim_poly_tab[] = {
@@ -1268,7 +1305,7 @@ struct bch_control *init_bch(int m, int t, unsigned int prim_poly)
goto fail;
}
#endif
- if ((m < min_m) || (m > max_m))
+ if ((m < min_m) || (m > BCH_MAX_M))
/*
* values of m greater than 15 are not currently supported;
* supporting m > 15 would require changing table base type
@@ -1276,6 +1313,13 @@ struct bch_control *init_bch(int m, int t, unsigned int prim_poly)
*/
goto fail;
+ if (t > BCH_MAX_T)
+ /*
+ * we can support larger than 64 bits if necessary, at the
+ * cost of higher stack usage.
+ */
+ goto fail;
+
/* sanity checks */
if ((t < 1) || (m*t >= ((1 << m)-1)))
/* invalid t value */
@@ -1303,6 +1347,7 @@ struct bch_control *init_bch(int m, int t, unsigned int prim_poly)
bch->syn = bch_alloc(2*t*sizeof(*bch->syn), &err);
bch->cache = bch_alloc(2*t*sizeof(*bch->cache), &err);
bch->elp = bch_alloc((t+1)*sizeof(struct gf_poly_deg1), &err);
+ bch->swap_bits = swap_bits;
for (i = 0; i < ARRAY_SIZE(bch->poly_2t); i++)
bch->poly_2t[i] = bch_alloc(GF_POLY_SZ(2*t), &err);
@@ -1329,16 +1374,16 @@ struct bch_control *init_bch(int m, int t, unsigned int prim_poly)
return bch;
fail:
- free_bch(bch);
+ bch_free(bch);
return NULL;
}
-EXPORT_SYMBOL_GPL(init_bch);
+EXPORT_SYMBOL_GPL(bch_init);
/**
- * free_bch - free the BCH control structure
+ * bch_free - free the BCH control structure
* @bch: BCH control structure to release
*/
-void free_bch(struct bch_control *bch)
+void bch_free(struct bch_control *bch)
{
unsigned int i;
@@ -1359,7 +1404,7 @@ void free_bch(struct bch_control *bch)
kfree(bch);
}
}
-EXPORT_SYMBOL_GPL(free_bch);
+EXPORT_SYMBOL_GPL(bch_free);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ivan Djelic <ivan.djelic at parrot.com>");
--
2.39.2
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