| Message ID | 20180419100935.175488049@linutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 19 Apr 2018 12:04:46 +0200 Thomas Gleixner <tglx@linutronix.de> wrote: > From: Thomas Gleixner <tglx@linutronix.de> > > The decoder library uses variable length arrays on stack. To get rid of > them it would be simple to allocate fixed length arrays on stack, but those > might become rather large. The other solution is to allocate the buffers in > the rs control structure, but this cannot be done as long as the structure > can be shared by several users. Sharing is desired because the RS polynom > tables are large and initialization is time consuming. > > To solve this split the codec information out of the control structure and > have a pointer to a shared codec in it. Instantiate the control structure > for each user, create a new codec if no shareable is avaiable yet. Adjust > all affected usage sites to the new scheme. > > This allows to add per instance decoder buffers to the control structure > later on. > > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Cc: Boris Brezillon <boris.brezillon@free-electrons.com> > Cc: Tony Luck <tony.luck@intel.com> > Cc: Kees Cook <keescook@chromium.org> > Cc: Segher Boessenkool <segher@kernel.crashing.org> > Cc: Kernel Hardening <kernel-hardening@lists.openwall.com> > Cc: Richard Weinberger <richard@nod.at> > Cc: Mike Snitzer <snitzer@redhat.com> > Cc: Anton Vorontsov <anton@enomsg.org> > Cc: Colin Cross <ccross@android.com> > Cc: Andrew Morton <akpm@linuxfoundation.org> > Cc: David Woodhouse <dwmw2@infradead.org> > Cc: Alasdair Kergon <agk@redhat.com> > > --- > drivers/mtd/nand/raw/cafe_nand.c | 7 + > drivers/mtd/nand/raw/diskonchip.c | 7 + For NAND relate stuff: Acked-by: Boris Brezillon <boris.brezillon@bootlin.com> Don't know which release this patch series is targeting, but if it's 4.18 I'll need an immutable branch just in case other patches touch the same files. > include/linux/rslib.h | 18 +++-- > lib/reed_solomon/decode_rs.c | 1 > lib/reed_solomon/encode_rs.c | 1 > lib/reed_solomon/reed_solomon.c | 144 ++++++++++++++++++++++------------------ > 6 files changed, 104 insertions(+), 74 deletions(-) > > --- a/drivers/mtd/nand/raw/cafe_nand.c > +++ b/drivers/mtd/nand/raw/cafe_nand.c > @@ -394,12 +394,13 @@ static int cafe_nand_read_page(struct mt > > for (i=0; i<8; i+=2) { > uint32_t tmp = cafe_readl(cafe, NAND_ECC_SYN01 + (i*2)); > - syn[i] = cafe->rs->index_of[tmp & 0xfff]; > - syn[i+1] = cafe->rs->index_of[(tmp >> 16) & 0xfff]; > + > + syn[i] = cafe->rs->codec->index_of[tmp & 0xfff]; > + syn[i+1] = cafe->rs->codec->index_of[(tmp >> 16) & 0xfff]; > } > > n = decode_rs16(cafe->rs, NULL, NULL, 1367, syn, 0, pos, 0, > - pat); > + pat); > > for (i = 0; i < n; i++) { > int p = pos[i]; > --- a/drivers/mtd/nand/raw/diskonchip.c > +++ b/drivers/mtd/nand/raw/diskonchip.c > @@ -142,6 +142,7 @@ static int doc_ecc_decode(struct rs_cont > int i, j, nerr, errpos[8]; > uint8_t parity; > uint16_t ds[4], s[5], tmp, errval[8], syn[4]; > + struct rs_codec *cd = rs->codec; > > memset(syn, 0, sizeof(syn)); > /* Convert the ecc bytes into words */ > @@ -162,15 +163,15 @@ static int doc_ecc_decode(struct rs_cont > for (j = 1; j < NROOTS; j++) { > if (ds[j] == 0) > continue; > - tmp = rs->index_of[ds[j]]; > + tmp = cd->index_of[ds[j]]; > for (i = 0; i < NROOTS; i++) > - s[i] ^= rs->alpha_to[rs_modnn(rs, tmp + (FCR + i) * j)]; > + s[i] ^= cd->alpha_to[rs_modnn(cd, tmp + (FCR + i) * j)]; > } > > /* Calc syn[i] = s[i] / alpha^(v + i) */ > for (i = 0; i < NROOTS; i++) { > if (s[i]) > - syn[i] = rs_modnn(rs, rs->index_of[s[i]] + (NN - FCR - i)); > + syn[i] = rs_modnn(cd, cd->index_of[s[i]] + (NN - FCR - i)); > } > /* Call the decoder library */ > nerr = decode_rs16(rs, NULL, NULL, 1019, syn, 0, errpos, 0, errval); > --- a/include/linux/rslib.h > +++ b/include/linux/rslib.h > @@ -13,7 +13,7 @@ > #include <linux/list.h> > > /** > - * struct rs_control - rs control structure > + * struct rs_codec - rs codec data > * > * @mm: Bits per symbol > * @nn: Symbols per block (= (1<<mm)-1) > @@ -27,9 +27,9 @@ > * @gfpoly: The primitive generator polynominal > * @gffunc: Function to generate the field, if non-canonical representation > * @users: Users of this structure > - * @list: List entry for the rs control list > + * @list: List entry for the rs codec list > */ > -struct rs_control { > +struct rs_codec { > int mm; > int nn; > uint16_t *alpha_to; > @@ -45,6 +45,14 @@ struct rs_control { > struct list_head list; > }; > > +/** > + * struct rs_control - rs control structure per instance > + * @codec: The codec used for this instance > + */ > +struct rs_control { > + struct rs_codec *codec; > +}; > + > /* General purpose RS codec, 8-bit data width, symbol width 1-15 bit */ > #ifdef CONFIG_REED_SOLOMON_ENC8 > int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par, > @@ -78,7 +86,7 @@ void free_rs(struct rs_control *rs); > > /** modulo replacement for galois field arithmetics > * > - * @rs: the rs control structure > + * @rs: Pointer to the RS codec > * @x: the value to reduce > * > * where > @@ -88,7 +96,7 @@ void free_rs(struct rs_control *rs); > * Simple arithmetic modulo would return a wrong result for values > * >= 3 * rs->nn > */ > -static inline int rs_modnn(struct rs_control *rs, int x) > +static inline int rs_modnn(struct rs_codec *rs, int x) > { > while (x >= rs->nn) { > x -= rs->nn; > --- a/lib/reed_solomon/decode_rs.c > +++ b/lib/reed_solomon/decode_rs.c > @@ -10,6 +10,7 @@ > * Generic data width independent code which is included by the wrappers. > */ > { > + struct rs_codec *rs = rsc->codec; > int deg_lambda, el, deg_omega; > int i, j, r, k, pad; > int nn = rs->nn; > --- a/lib/reed_solomon/encode_rs.c > +++ b/lib/reed_solomon/encode_rs.c > @@ -10,6 +10,7 @@ > * Generic data width independent code which is included by the wrappers. > */ > { > + struct rs_codec *rs = rsc->codec; > int i, j, pad; > int nn = rs->nn; > int nroots = rs->nroots; > --- a/lib/reed_solomon/reed_solomon.c > +++ b/lib/reed_solomon/reed_solomon.c > @@ -11,22 +11,23 @@ > * > * The generic Reed Solomon library provides runtime configurable > * encoding / decoding of RS codes. > - * Each user must call init_rs to get a pointer to a rs_control > - * structure for the given rs parameters. This structure is either > - * generated or a already available matching control structure is used. > - * If a structure is generated then the polynomial arrays for > - * fast encoding / decoding are built. This can take some time so > - * make sure not to call this function from a time critical path. > - * Usually a module / driver should initialize the necessary > - * rs_control structure on module / driver init and release it > - * on exit. > - * The encoding puts the calculated syndrome into a given syndrome > - * buffer. > - * The decoding is a two step process. The first step calculates > - * the syndrome over the received (data + syndrome) and calls the > - * second stage, which does the decoding / error correction itself. > - * Many hw encoders provide a syndrome calculation over the received > - * data + syndrome and can call the second stage directly. > + * > + * Each user must call init_rs to get a pointer to a rs_control structure > + * for the given rs parameters. The control struct is unique per instance. > + * It points to a codec which can be shared by multiple control structures. > + * If a codec is newly allocated then the polynomial arrays for fast > + * encoding / decoding are built. This can take some time so make sure not > + * to call this function from a time critical path. Usually a module / > + * driver should initialize the necessary rs_control structure on module / > + * driver init and release it on exit. > + * > + * The encoding puts the calculated syndrome into a given syndrome buffer. > + * > + * The decoding is a two step process. The first step calculates the > + * syndrome over the received (data + syndrome) and calls the second stage, > + * which does the decoding / error correction itself. Many hw encoders > + * provide a syndrome calculation over the received data + syndrome and can > + * call the second stage directly. > */ > #include <linux/errno.h> > #include <linux/kernel.h> > @@ -36,13 +37,13 @@ > #include <linux/slab.h> > #include <linux/mutex.h> > > -/* This list holds all currently allocated rs control structures */ > -static LIST_HEAD (rslist); > +/* This list holds all currently allocated rs codec structures */ > +static LIST_HEAD(codec_list); > /* Protection for the list */ > static DEFINE_MUTEX(rslistlock); > > /** > - * rs_init - Initialize a Reed-Solomon codec > + * codec_init - Initialize a Reed-Solomon codec > * @symsize: symbol size, bits (1-8) > * @gfpoly: Field generator polynomial coefficients > * @gffunc: Field generator function > @@ -50,18 +51,17 @@ static DEFINE_MUTEX(rslistlock); > * @prim: primitive element to generate polynomial roots > * @nroots: RS code generator polynomial degree (number of roots) > * > - * Allocate a control structure and the polynom arrays for faster > + * Allocate a codec structure and the polynom arrays for faster > * en/decoding. Fill the arrays according to the given parameters. > */ > -static struct rs_control *rs_init(int symsize, int gfpoly, int (*gffunc)(int), > - int fcr, int prim, int nroots) > +static struct rs_codec *codec_init(int symsize, int gfpoly, int (*gffunc)(int), > + int fcr, int prim, int nroots) > { > - struct rs_control *rs; > int i, j, sr, root, iprim; > + struct rs_codec *rs; > > - /* Allocate the control structure */ > - rs = kmalloc(sizeof (struct rs_control), GFP_KERNEL); > - if (rs == NULL) > + rs = kmalloc(sizeof(*rs), GFP_KERNEL); > + if (!rs) > return NULL; > > INIT_LIST_HEAD(&rs->list); > @@ -138,6 +138,9 @@ static struct rs_control *rs_init(int sy > /* convert rs->genpoly[] to index form for quicker encoding */ > for (i = 0; i <= nroots; i++) > rs->genpoly[i] = rs->index_of[rs->genpoly[i]]; > + > + rs->users = 1; > + list_add(&rs->list, &codec_list); > return rs; > > /* Error exit */ > @@ -154,26 +157,36 @@ static struct rs_control *rs_init(int sy > > > /** > - * free_rs - Free the rs control structure, if it is no longer used > - * @rs: the control structure which is not longer used by the > + * free_rs - Free the rs control structure > + * @rs: The control structure which is not longer used by the > * caller > + * > + * Free the control structure. If @rs is the last user of the associated > + * codec, free the codec as well. > */ > void free_rs(struct rs_control *rs) > { > + struct rs_codec *cd; > + > + if (!rs) > + return; > + > + cd = rs->codec; > mutex_lock(&rslistlock); > - rs->users--; > - if(!rs->users) { > - list_del(&rs->list); > - kfree(rs->alpha_to); > - kfree(rs->index_of); > - kfree(rs->genpoly); > - kfree(rs); > + cd->users--; > + if(!cd->users) { > + list_del(&cd->list); > + kfree(cd->alpha_to); > + kfree(cd->index_of); > + kfree(cd->genpoly); > + kfree(cd); > } > mutex_unlock(&rslistlock); > + kfree(rs); > } > > /** > - * init_rs_internal - Find a matching or allocate a new rs control structure > + * init_rs_internal - Allocate rs control, find a matching codec or allocate a new one > * @symsize: the symbol size (number of bits) > * @gfpoly: the extended Galois field generator polynomial coefficients, > * with the 0th coefficient in the low order bit. The polynomial > @@ -190,8 +203,8 @@ static struct rs_control *init_rs_intern > int (*gffunc)(int), int fcr, > int prim, int nroots) > { > - struct list_head *tmp; > - struct rs_control *rs; > + struct list_head *tmp; > + struct rs_control *rs; > > /* Sanity checks */ > if (symsize < 1) > @@ -203,33 +216,39 @@ static struct rs_control *init_rs_intern > if (nroots < 0 || nroots >= (1<<symsize)) > return NULL; > > + rs = kzalloc(sizeof(*rs), GFP_KERNEL); > + if (!rs) > + return NULL; > + > mutex_lock(&rslistlock); > > /* Walk through the list and look for a matching entry */ > - list_for_each(tmp, &rslist) { > - rs = list_entry(tmp, struct rs_control, list); > - if (symsize != rs->mm) > + list_for_each(tmp, &codec_list) { > + struct rs_codec *cd = list_entry(tmp, struct rs_codec, list); > + > + if (symsize != cd->mm) > continue; > - if (gfpoly != rs->gfpoly) > + if (gfpoly != cd->gfpoly) > continue; > - if (gffunc != rs->gffunc) > + if (gffunc != cd->gffunc) > continue; > - if (fcr != rs->fcr) > + if (fcr != cd->fcr) > continue; > - if (prim != rs->prim) > + if (prim != cd->prim) > continue; > - if (nroots != rs->nroots) > + if (nroots != cd->nroots) > continue; > /* We have a matching one already */ > - rs->users++; > + cd->users++; > + rs->codec = cd; > goto out; > } > > /* Create a new one */ > - rs = rs_init(symsize, gfpoly, gffunc, fcr, prim, nroots); > - if (rs) { > - rs->users = 1; > - list_add(&rs->list, &rslist); > + rs->codec = codec_init(symsize, gfpoly, gffunc, fcr, prim, nroots); > + if (!rs->codec) { > + kfree(rs); > + rs = NULL; > } > out: > mutex_unlock(&rslistlock); > @@ -237,7 +256,7 @@ static struct rs_control *init_rs_intern > } > > /** > - * init_rs - Find a matching or allocate a new rs control structure > + * init_rs - Create a RS control struct and initialize it > * @symsize: the symbol size (number of bits) > * @gfpoly: the extended Galois field generator polynomial coefficients, > * with the 0th coefficient in the low order bit. The polynomial > @@ -254,9 +273,8 @@ struct rs_control *init_rs(int symsize, > } > > /** > - * init_rs_non_canonical - Find a matching or allocate a new rs control > - * structure, for fields with non-canonical > - * representation > + * init_rs_non_canonical - Allocate rs control struct for fields with > + * non-canonical representation > * @symsize: the symbol size (number of bits) > * @gffunc: pointer to function to generate the next field element, > * or the multiplicative identity element if given 0. Used > @@ -275,7 +293,7 @@ struct rs_control *init_rs_non_canonical > #ifdef CONFIG_REED_SOLOMON_ENC8 > /** > * encode_rs8 - Calculate the parity for data values (8bit data width) > - * @rs: the rs control structure > + * @rsc: the rs control structure > * @data: data field of a given type > * @len: data length > * @par: parity data, must be initialized by caller (usually all 0) > @@ -285,7 +303,7 @@ struct rs_control *init_rs_non_canonical > * symbol size > 8. The calling code must take care of encoding of the > * syndrome result for storage itself. > */ > -int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par, > +int encode_rs8(struct rs_control *rsc, uint8_t *data, int len, uint16_t *par, > uint16_t invmsk) > { > #include "encode_rs.c" > @@ -296,7 +314,7 @@ EXPORT_SYMBOL_GPL(encode_rs8); > #ifdef CONFIG_REED_SOLOMON_DEC8 > /** > * decode_rs8 - Decode codeword (8bit data width) > - * @rs: the rs control structure > + * @rsc: the rs control structure > * @data: data field of a given type > * @par: received parity data field > * @len: data length > @@ -311,7 +329,7 @@ EXPORT_SYMBOL_GPL(encode_rs8); > * syndrome result and the received parity before calling this code. > * Returns the number of corrected bits or -EBADMSG for uncorrectable errors. > */ > -int decode_rs8(struct rs_control *rs, uint8_t *data, uint16_t *par, int len, > +int decode_rs8(struct rs_control *rsc, uint8_t *data, uint16_t *par, int len, > uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk, > uint16_t *corr) > { > @@ -323,7 +341,7 @@ EXPORT_SYMBOL_GPL(decode_rs8); > #ifdef CONFIG_REED_SOLOMON_ENC16 > /** > * encode_rs16 - Calculate the parity for data values (16bit data width) > - * @rs: the rs control structure > + * @rsc: the rs control structure > * @data: data field of a given type > * @len: data length > * @par: parity data, must be initialized by caller (usually all 0) > @@ -331,7 +349,7 @@ EXPORT_SYMBOL_GPL(decode_rs8); > * > * Each field in the data array contains up to symbol size bits of valid data. > */ > -int encode_rs16(struct rs_control *rs, uint16_t *data, int len, uint16_t *par, > +int encode_rs16(struct rs_control *rsc, uint16_t *data, int len, uint16_t *par, > uint16_t invmsk) > { > #include "encode_rs.c" > @@ -342,7 +360,7 @@ EXPORT_SYMBOL_GPL(encode_rs16); > #ifdef CONFIG_REED_SOLOMON_DEC16 > /** > * decode_rs16 - Decode codeword (16bit data width) > - * @rs: the rs control structure > + * @rsc: the rs control structure > * @data: data field of a given type > * @par: received parity data field > * @len: data length > @@ -355,7 +373,7 @@ EXPORT_SYMBOL_GPL(encode_rs16); > * Each field in the data array contains up to symbol size bits of valid data. > * Returns the number of corrected bits or -EBADMSG for uncorrectable errors. > */ > -int decode_rs16(struct rs_control *rs, uint16_t *data, uint16_t *par, int len, > +int decode_rs16(struct rs_control *rsc, uint16_t *data, uint16_t *par, int len, > uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk, > uint16_t *corr) > { > > > > >
--- a/drivers/mtd/nand/raw/cafe_nand.c +++ b/drivers/mtd/nand/raw/cafe_nand.c @@ -394,12 +394,13 @@ static int cafe_nand_read_page(struct mt for (i=0; i<8; i+=2) { uint32_t tmp = cafe_readl(cafe, NAND_ECC_SYN01 + (i*2)); - syn[i] = cafe->rs->index_of[tmp & 0xfff]; - syn[i+1] = cafe->rs->index_of[(tmp >> 16) & 0xfff]; + + syn[i] = cafe->rs->codec->index_of[tmp & 0xfff]; + syn[i+1] = cafe->rs->codec->index_of[(tmp >> 16) & 0xfff]; } n = decode_rs16(cafe->rs, NULL, NULL, 1367, syn, 0, pos, 0, - pat); + pat); for (i = 0; i < n; i++) { int p = pos[i]; --- a/drivers/mtd/nand/raw/diskonchip.c +++ b/drivers/mtd/nand/raw/diskonchip.c @@ -142,6 +142,7 @@ static int doc_ecc_decode(struct rs_cont int i, j, nerr, errpos[8]; uint8_t parity; uint16_t ds[4], s[5], tmp, errval[8], syn[4]; + struct rs_codec *cd = rs->codec; memset(syn, 0, sizeof(syn)); /* Convert the ecc bytes into words */ @@ -162,15 +163,15 @@ static int doc_ecc_decode(struct rs_cont for (j = 1; j < NROOTS; j++) { if (ds[j] == 0) continue; - tmp = rs->index_of[ds[j]]; + tmp = cd->index_of[ds[j]]; for (i = 0; i < NROOTS; i++) - s[i] ^= rs->alpha_to[rs_modnn(rs, tmp + (FCR + i) * j)]; + s[i] ^= cd->alpha_to[rs_modnn(cd, tmp + (FCR + i) * j)]; } /* Calc syn[i] = s[i] / alpha^(v + i) */ for (i = 0; i < NROOTS; i++) { if (s[i]) - syn[i] = rs_modnn(rs, rs->index_of[s[i]] + (NN - FCR - i)); + syn[i] = rs_modnn(cd, cd->index_of[s[i]] + (NN - FCR - i)); } /* Call the decoder library */ nerr = decode_rs16(rs, NULL, NULL, 1019, syn, 0, errpos, 0, errval); --- a/include/linux/rslib.h +++ b/include/linux/rslib.h @@ -13,7 +13,7 @@ #include <linux/list.h> /** - * struct rs_control - rs control structure + * struct rs_codec - rs codec data * * @mm: Bits per symbol * @nn: Symbols per block (= (1<<mm)-1) @@ -27,9 +27,9 @@ * @gfpoly: The primitive generator polynominal * @gffunc: Function to generate the field, if non-canonical representation * @users: Users of this structure - * @list: List entry for the rs control list + * @list: List entry for the rs codec list */ -struct rs_control { +struct rs_codec { int mm; int nn; uint16_t *alpha_to; @@ -45,6 +45,14 @@ struct rs_control { struct list_head list; }; +/** + * struct rs_control - rs control structure per instance + * @codec: The codec used for this instance + */ +struct rs_control { + struct rs_codec *codec; +}; + /* General purpose RS codec, 8-bit data width, symbol width 1-15 bit */ #ifdef CONFIG_REED_SOLOMON_ENC8 int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par, @@ -78,7 +86,7 @@ void free_rs(struct rs_control *rs); /** modulo replacement for galois field arithmetics * - * @rs: the rs control structure + * @rs: Pointer to the RS codec * @x: the value to reduce * * where @@ -88,7 +96,7 @@ void free_rs(struct rs_control *rs); * Simple arithmetic modulo would return a wrong result for values * >= 3 * rs->nn */ -static inline int rs_modnn(struct rs_control *rs, int x) +static inline int rs_modnn(struct rs_codec *rs, int x) { while (x >= rs->nn) { x -= rs->nn; --- a/lib/reed_solomon/decode_rs.c +++ b/lib/reed_solomon/decode_rs.c @@ -10,6 +10,7 @@ * Generic data width independent code which is included by the wrappers. */ { + struct rs_codec *rs = rsc->codec; int deg_lambda, el, deg_omega; int i, j, r, k, pad; int nn = rs->nn; --- a/lib/reed_solomon/encode_rs.c +++ b/lib/reed_solomon/encode_rs.c @@ -10,6 +10,7 @@ * Generic data width independent code which is included by the wrappers. */ { + struct rs_codec *rs = rsc->codec; int i, j, pad; int nn = rs->nn; int nroots = rs->nroots; --- a/lib/reed_solomon/reed_solomon.c +++ b/lib/reed_solomon/reed_solomon.c @@ -11,22 +11,23 @@ * * The generic Reed Solomon library provides runtime configurable * encoding / decoding of RS codes. - * Each user must call init_rs to get a pointer to a rs_control - * structure for the given rs parameters. This structure is either - * generated or a already available matching control structure is used. - * If a structure is generated then the polynomial arrays for - * fast encoding / decoding are built. This can take some time so - * make sure not to call this function from a time critical path. - * Usually a module / driver should initialize the necessary - * rs_control structure on module / driver init and release it - * on exit. - * The encoding puts the calculated syndrome into a given syndrome - * buffer. - * The decoding is a two step process. The first step calculates - * the syndrome over the received (data + syndrome) and calls the - * second stage, which does the decoding / error correction itself. - * Many hw encoders provide a syndrome calculation over the received - * data + syndrome and can call the second stage directly. + * + * Each user must call init_rs to get a pointer to a rs_control structure + * for the given rs parameters. The control struct is unique per instance. + * It points to a codec which can be shared by multiple control structures. + * If a codec is newly allocated then the polynomial arrays for fast + * encoding / decoding are built. This can take some time so make sure not + * to call this function from a time critical path. Usually a module / + * driver should initialize the necessary rs_control structure on module / + * driver init and release it on exit. + * + * The encoding puts the calculated syndrome into a given syndrome buffer. + * + * The decoding is a two step process. The first step calculates the + * syndrome over the received (data + syndrome) and calls the second stage, + * which does the decoding / error correction itself. Many hw encoders + * provide a syndrome calculation over the received data + syndrome and can + * call the second stage directly. */ #include <linux/errno.h> #include <linux/kernel.h> @@ -36,13 +37,13 @@ #include <linux/slab.h> #include <linux/mutex.h> -/* This list holds all currently allocated rs control structures */ -static LIST_HEAD (rslist); +/* This list holds all currently allocated rs codec structures */ +static LIST_HEAD(codec_list); /* Protection for the list */ static DEFINE_MUTEX(rslistlock); /** - * rs_init - Initialize a Reed-Solomon codec + * codec_init - Initialize a Reed-Solomon codec * @symsize: symbol size, bits (1-8) * @gfpoly: Field generator polynomial coefficients * @gffunc: Field generator function @@ -50,18 +51,17 @@ static DEFINE_MUTEX(rslistlock); * @prim: primitive element to generate polynomial roots * @nroots: RS code generator polynomial degree (number of roots) * - * Allocate a control structure and the polynom arrays for faster + * Allocate a codec structure and the polynom arrays for faster * en/decoding. Fill the arrays according to the given parameters. */ -static struct rs_control *rs_init(int symsize, int gfpoly, int (*gffunc)(int), - int fcr, int prim, int nroots) +static struct rs_codec *codec_init(int symsize, int gfpoly, int (*gffunc)(int), + int fcr, int prim, int nroots) { - struct rs_control *rs; int i, j, sr, root, iprim; + struct rs_codec *rs; - /* Allocate the control structure */ - rs = kmalloc(sizeof (struct rs_control), GFP_KERNEL); - if (rs == NULL) + rs = kmalloc(sizeof(*rs), GFP_KERNEL); + if (!rs) return NULL; INIT_LIST_HEAD(&rs->list); @@ -138,6 +138,9 @@ static struct rs_control *rs_init(int sy /* convert rs->genpoly[] to index form for quicker encoding */ for (i = 0; i <= nroots; i++) rs->genpoly[i] = rs->index_of[rs->genpoly[i]]; + + rs->users = 1; + list_add(&rs->list, &codec_list); return rs; /* Error exit */ @@ -154,26 +157,36 @@ static struct rs_control *rs_init(int sy /** - * free_rs - Free the rs control structure, if it is no longer used - * @rs: the control structure which is not longer used by the + * free_rs - Free the rs control structure + * @rs: The control structure which is not longer used by the * caller + * + * Free the control structure. If @rs is the last user of the associated + * codec, free the codec as well. */ void free_rs(struct rs_control *rs) { + struct rs_codec *cd; + + if (!rs) + return; + + cd = rs->codec; mutex_lock(&rslistlock); - rs->users--; - if(!rs->users) { - list_del(&rs->list); - kfree(rs->alpha_to); - kfree(rs->index_of); - kfree(rs->genpoly); - kfree(rs); + cd->users--; + if(!cd->users) { + list_del(&cd->list); + kfree(cd->alpha_to); + kfree(cd->index_of); + kfree(cd->genpoly); + kfree(cd); } mutex_unlock(&rslistlock); + kfree(rs); } /** - * init_rs_internal - Find a matching or allocate a new rs control structure + * init_rs_internal - Allocate rs control, find a matching codec or allocate a new one * @symsize: the symbol size (number of bits) * @gfpoly: the extended Galois field generator polynomial coefficients, * with the 0th coefficient in the low order bit. The polynomial @@ -190,8 +203,8 @@ static struct rs_control *init_rs_intern int (*gffunc)(int), int fcr, int prim, int nroots) { - struct list_head *tmp; - struct rs_control *rs; + struct list_head *tmp; + struct rs_control *rs; /* Sanity checks */ if (symsize < 1) @@ -203,33 +216,39 @@ static struct rs_control *init_rs_intern if (nroots < 0 || nroots >= (1<<symsize)) return NULL; + rs = kzalloc(sizeof(*rs), GFP_KERNEL); + if (!rs) + return NULL; + mutex_lock(&rslistlock); /* Walk through the list and look for a matching entry */ - list_for_each(tmp, &rslist) { - rs = list_entry(tmp, struct rs_control, list); - if (symsize != rs->mm) + list_for_each(tmp, &codec_list) { + struct rs_codec *cd = list_entry(tmp, struct rs_codec, list); + + if (symsize != cd->mm) continue; - if (gfpoly != rs->gfpoly) + if (gfpoly != cd->gfpoly) continue; - if (gffunc != rs->gffunc) + if (gffunc != cd->gffunc) continue; - if (fcr != rs->fcr) + if (fcr != cd->fcr) continue; - if (prim != rs->prim) + if (prim != cd->prim) continue; - if (nroots != rs->nroots) + if (nroots != cd->nroots) continue; /* We have a matching one already */ - rs->users++; + cd->users++; + rs->codec = cd; goto out; } /* Create a new one */ - rs = rs_init(symsize, gfpoly, gffunc, fcr, prim, nroots); - if (rs) { - rs->users = 1; - list_add(&rs->list, &rslist); + rs->codec = codec_init(symsize, gfpoly, gffunc, fcr, prim, nroots); + if (!rs->codec) { + kfree(rs); + rs = NULL; } out: mutex_unlock(&rslistlock); @@ -237,7 +256,7 @@ static struct rs_control *init_rs_intern } /** - * init_rs - Find a matching or allocate a new rs control structure + * init_rs - Create a RS control struct and initialize it * @symsize: the symbol size (number of bits) * @gfpoly: the extended Galois field generator polynomial coefficients, * with the 0th coefficient in the low order bit. The polynomial @@ -254,9 +273,8 @@ struct rs_control *init_rs(int symsize, } /** - * init_rs_non_canonical - Find a matching or allocate a new rs control - * structure, for fields with non-canonical - * representation + * init_rs_non_canonical - Allocate rs control struct for fields with + * non-canonical representation * @symsize: the symbol size (number of bits) * @gffunc: pointer to function to generate the next field element, * or the multiplicative identity element if given 0. Used @@ -275,7 +293,7 @@ struct rs_control *init_rs_non_canonical #ifdef CONFIG_REED_SOLOMON_ENC8 /** * encode_rs8 - Calculate the parity for data values (8bit data width) - * @rs: the rs control structure + * @rsc: the rs control structure * @data: data field of a given type * @len: data length * @par: parity data, must be initialized by caller (usually all 0) @@ -285,7 +303,7 @@ struct rs_control *init_rs_non_canonical * symbol size > 8. The calling code must take care of encoding of the * syndrome result for storage itself. */ -int encode_rs8(struct rs_control *rs, uint8_t *data, int len, uint16_t *par, +int encode_rs8(struct rs_control *rsc, uint8_t *data, int len, uint16_t *par, uint16_t invmsk) { #include "encode_rs.c" @@ -296,7 +314,7 @@ EXPORT_SYMBOL_GPL(encode_rs8); #ifdef CONFIG_REED_SOLOMON_DEC8 /** * decode_rs8 - Decode codeword (8bit data width) - * @rs: the rs control structure + * @rsc: the rs control structure * @data: data field of a given type * @par: received parity data field * @len: data length @@ -311,7 +329,7 @@ EXPORT_SYMBOL_GPL(encode_rs8); * syndrome result and the received parity before calling this code. * Returns the number of corrected bits or -EBADMSG for uncorrectable errors. */ -int decode_rs8(struct rs_control *rs, uint8_t *data, uint16_t *par, int len, +int decode_rs8(struct rs_control *rsc, uint8_t *data, uint16_t *par, int len, uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk, uint16_t *corr) { @@ -323,7 +341,7 @@ EXPORT_SYMBOL_GPL(decode_rs8); #ifdef CONFIG_REED_SOLOMON_ENC16 /** * encode_rs16 - Calculate the parity for data values (16bit data width) - * @rs: the rs control structure + * @rsc: the rs control structure * @data: data field of a given type * @len: data length * @par: parity data, must be initialized by caller (usually all 0) @@ -331,7 +349,7 @@ EXPORT_SYMBOL_GPL(decode_rs8); * * Each field in the data array contains up to symbol size bits of valid data. */ -int encode_rs16(struct rs_control *rs, uint16_t *data, int len, uint16_t *par, +int encode_rs16(struct rs_control *rsc, uint16_t *data, int len, uint16_t *par, uint16_t invmsk) { #include "encode_rs.c" @@ -342,7 +360,7 @@ EXPORT_SYMBOL_GPL(encode_rs16); #ifdef CONFIG_REED_SOLOMON_DEC16 /** * decode_rs16 - Decode codeword (16bit data width) - * @rs: the rs control structure + * @rsc: the rs control structure * @data: data field of a given type * @par: received parity data field * @len: data length @@ -355,7 +373,7 @@ EXPORT_SYMBOL_GPL(encode_rs16); * Each field in the data array contains up to symbol size bits of valid data. * Returns the number of corrected bits or -EBADMSG for uncorrectable errors. */ -int decode_rs16(struct rs_control *rs, uint16_t *data, uint16_t *par, int len, +int decode_rs16(struct rs_control *rsc, uint16_t *data, uint16_t *par, int len, uint16_t *s, int no_eras, int *eras_pos, uint16_t invmsk, uint16_t *corr) {