diff options
Diffstat (limited to 'lib/reed_solomon/reed_solomon.c')
| -rw-r--r-- | lib/reed_solomon/reed_solomon.c | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/lib/reed_solomon/reed_solomon.c b/lib/reed_solomon/reed_solomon.c index cb21e8b5a4e0e..dfcf54242fb92 100644 --- a/lib/reed_solomon/reed_solomon.c +++ b/lib/reed_solomon/reed_solomon.c @@ -37,6 +37,18 @@ #include <linux/slab.h> #include <linux/mutex.h> +enum { + RS_DECODE_LAMBDA, + RS_DECODE_SYN, + RS_DECODE_B, + RS_DECODE_T, + RS_DECODE_OMEGA, + RS_DECODE_ROOT, + RS_DECODE_REG, + RS_DECODE_LOC, + RS_DECODE_NUM_BUFFERS +}; + /* This list holds all currently allocated rs codec structures */ static LIST_HEAD(codec_list); /* Protection for the list */ @@ -204,6 +216,7 @@ static struct rs_control *init_rs_internal(int symsize, int gfpoly, { struct list_head *tmp; struct rs_control *rs; + unsigned int bsize; /* Sanity checks */ if (symsize < 1) @@ -215,7 +228,13 @@ static struct rs_control *init_rs_internal(int symsize, int gfpoly, if (nroots < 0 || nroots >= (1<<symsize)) return NULL; - rs = kzalloc(sizeof(*rs), GFP_KERNEL); + /* + * The decoder needs buffers in each control struct instance to + * avoid variable size or large fixed size allocations on + * stack. Size the buffers to arrays of [nroots + 1]. + */ + bsize = sizeof(uint16_t) * RS_DECODE_NUM_BUFFERS * (nroots + 1); + rs = kzalloc(sizeof(*rs) + bsize, gfp); if (!rs) return NULL; @@ -330,6 +349,11 @@ EXPORT_SYMBOL_GPL(encode_rs8); * The syndrome and parity uses a uint16_t data type to enable * symbol size > 8. The calling code must take care of decoding of the * syndrome result and the received parity before calling this code. + * + * Note: The rs_control struct @rsc contains buffers which are used for + * decoding, so the caller has to ensure that decoder invocations are + * serialized. + * * Returns the number of corrected bits or -EBADMSG for uncorrectable errors. */ int decode_rs8(struct rs_control *rsc, uint8_t *data, uint16_t *par, int len, @@ -374,6 +398,11 @@ EXPORT_SYMBOL_GPL(encode_rs16); * @corr: buffer to store correction bitmask on eras_pos * * Each field in the data array contains up to symbol size bits of valid data. + * + * Note: The rc_control struct @rsc contains buffers which are used for + * decoding, so the caller has to ensure that decoder invocations are + * serialized. + * * Returns the number of corrected bits or -EBADMSG for uncorrectable errors. */ int decode_rs16(struct rs_control *rsc, uint16_t *data, uint16_t *par, int len, |