6 files changed, 100 insertions, 70 deletions

diff --git a/drivers/mtd/nand/raw/cafe_nand.c b/drivers/mtd/nand/raw/cafe_nand.c
index d8c8c9d1e640..d721f489b38b 100644
--- 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 mtd_info *mtd, struct nand_chip *chip,
 
                 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];
diff --git a/drivers/mtd/nand/raw/diskonchip.c b/drivers/mtd/nand/raw/diskonchip.c
index 86a258de0b75..73308333e788 100644
--- a/drivers/mtd/nand/raw/diskonchip.c
+++ b/drivers/mtd/nand/raw/diskonchip.c
@@ -140,6 +140,7 @@ static int doc_ecc_decode(struct rs_control *rs, uint8_t *data, uint8_t *ecc)
         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 */
@@ -160,15 +161,15 @@ static int doc_ecc_decode(struct rs_control *rs, uint8_t *data, uint8_t *ecc)
         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);
diff --git a/include/linux/rslib.h b/include/linux/rslib.h
index 27652c18bf8c..6703311beea3 100644
--- a/include/linux/rslib.h
+++ b/include/linux/rslib.h
@@ -15,7 +15,7 @@
 #include <linux/gfp.h>          /* for GFP_KERNEL */
 
 /**
- * struct rs_control - rs control structure
+ * struct rs_codec - rs codec data
  *
  * @mm:         Bits per symbol
  * @nn:         Symbols per block (= (1<<mm)-1)
@@ -29,9 +29,9 @@
  * @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;
@@ -47,6 +47,14 @@ 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,
@@ -69,7 +77,6 @@ int decode_rs16(struct rs_control *rs, uint16_t *data, uint16_t *par, int len,
                 uint16_t *corr);
 #endif
 
-/* Create or get a matching rs control structure */
 struct rs_control *init_rs_gfp(int symsize, int gfpoly, int fcr, int prim,
                                int nroots, gfp_t gfp);
 
@@ -100,7 +107,7 @@ 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
@@ -110,7 +117,7 @@ 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;
diff --git a/lib/reed_solomon/decode_rs.c b/lib/reed_solomon/decode_rs.c
index d61007ade4a0..794cced31c75 100644
--- 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;
diff --git a/lib/reed_solomon/encode_rs.c b/lib/reed_solomon/encode_rs.c
index 10ca1ebb13dd..9112d46e869e 100644
--- 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;
diff --git a/lib/reed_solomon/reed_solomon.c b/lib/reed_solomon/reed_solomon.c
index 02c19ecffc28..cb21e8b5a4e0 100644
--- 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
@@ -51,14 +52,14 @@ static DEFINE_MUTEX(rslistlock);
  * @nroots:     RS code generator polynomial degree (number of roots)
  * @gfp:        GFP_ flags for allocations
  *
- * 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, gfp_t gfp)
+static struct rs_codec *codec_init(int symsize, int gfpoly, int (*gffunc)(int),
+                                   int fcr, int prim, int nroots, gfp_t gfp)
 {
-        struct rs_control *rs;
         int i, j, sr, root, iprim;
+        struct rs_codec *rs;
 
         rs = kzalloc(sizeof(*rs), gfp);
         if (!rs)
@@ -138,6 +139,9 @@ static struct rs_control *rs_init(int symsize, int gfpoly, int (*gffunc)(int),
         /* 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;
 
 err:
@@ -150,27 +154,37 @@ err:
 
 
 /**
- *  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);
 }
 EXPORT_SYMBOL_GPL(free_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
@@ -201,33 +215,39 @@ 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);
+        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, gfp);
-        if (rs) {
-                rs->users = 1;
-                list_add(&rs->list, &rslist);
+        rs->codec = codec_init(symsize, gfpoly, gffunc, fcr, prim, nroots, gfp);
+        if (!rs->codec) {
+                kfree(rs);
+                rs = NULL;
         }
 out:
         mutex_unlock(&rslistlock);
@@ -235,7 +255,7 @@ out:
 }
 
 /**
- * init_rs_gfp - Find a matching or allocate a new rs control structure
+ * init_rs_gfp - 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 +274,8 @@ struct rs_control *init_rs_gfp(int symsize, int gfpoly, int fcr, int prim,
 EXPORT_SYMBOL_GPL(init_rs_gfp);
 
 /**
- * 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
@@ -277,7 +296,7 @@ EXPORT_SYMBOL_GPL(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)
@@ -287,7 +306,7 @@ EXPORT_SYMBOL_GPL(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"
@@ -298,7 +317,7 @@ 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
@@ -313,7 +332,7 @@ 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)
 {
@@ -325,7 +344,7 @@ 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)
@@ -333,7 +352,7 @@ 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"
@@ -344,7 +363,7 @@ 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
@@ -357,7 +376,7 @@ 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)
 {