[MTD NAND] Allocate chip->buffers separately to allow it to be overridden

In particular, the board driver might need it to be DMAable.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

3 files changed, 26 insertions, 17 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 492ff9d1a35c..e1e81a9543e8 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -767,8 +767,8 @@ static int nand_read_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
         int eccbytes = chip->ecc.bytes;
         int eccsteps = chip->ecc.steps;
         uint8_t *p = buf;
-        uint8_t *ecc_calc = chip->buffers.ecccalc;
-        uint8_t *ecc_code = chip->buffers.ecccode;
+        uint8_t *ecc_calc = chip->buffers->ecccalc;
+        uint8_t *ecc_code = chip->buffers->ecccode;
         int *eccpos = chip->ecc.layout->eccpos;
 
         nand_read_page_raw(mtd, chip, buf);
@@ -809,8 +809,8 @@ static int nand_read_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
         int eccbytes = chip->ecc.bytes;
         int eccsteps = chip->ecc.steps;
         uint8_t *p = buf;
-        uint8_t *ecc_calc = chip->buffers.ecccalc;
-        uint8_t *ecc_code = chip->buffers.ecccode;
+        uint8_t *ecc_calc = chip->buffers->ecccalc;
+        uint8_t *ecc_code = chip->buffers->ecccode;
         int *eccpos = chip->ecc.layout->eccpos;
 
         for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
@@ -971,7 +971,7 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
         page = realpage & chip->pagemask;
 
         col = (int)(from & (mtd->writesize - 1));
-        chip->oob_poi = chip->buffers.oobrbuf;
+        chip->oob_poi = chip->buffers->oobrbuf;
 
         buf = ops->datbuf;
         oob = ops->oobbuf;
@@ -982,7 +982,7 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
 
                 /* Is the current page in the buffer ? */
                 if (realpage != chip->pagebuf || oob) {
-                        bufpoi = aligned ? buf : chip->buffers.databuf;
+                        bufpoi = aligned ? buf : chip->buffers->databuf;
 
                         if (likely(sndcmd)) {
                                 chip->cmdfunc(mtd, NAND_CMD_READ0, 0x00, page);
@@ -997,7 +997,7 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
                         /* Transfer not aligned data */
                         if (!aligned) {
                                 chip->pagebuf = realpage;
-                                memcpy(buf, chip->buffers.databuf + col, bytes);
+                                memcpy(buf, chip->buffers->databuf + col, bytes);
                         }
 
                         buf += bytes;
@@ -1024,7 +1024,7 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
                                         nand_wait_ready(mtd);
                         }
                 } else {
-                        memcpy(buf, chip->buffers.databuf + col, bytes);
+                        memcpy(buf, chip->buffers->databuf + col, bytes);
                         buf += bytes;
                 }
 
@@ -1267,7 +1267,7 @@ static int nand_do_read_oob(struct mtd_info *mtd, loff_t from,
         realpage = (int)(from >> chip->page_shift);
         page = realpage & chip->pagemask;
 
-        chip->oob_poi = chip->buffers.oobrbuf;
+        chip->oob_poi = chip->buffers->oobrbuf;
 
         while(1) {
                 sndcmd = chip->ecc.read_oob(mtd, chip, page, sndcmd);
@@ -1392,7 +1392,7 @@ static void nand_write_page_swecc(struct mtd_info *mtd, struct nand_chip *chip,
         int i, eccsize = chip->ecc.size;
         int eccbytes = chip->ecc.bytes;
         int eccsteps = chip->ecc.steps;
-        uint8_t *ecc_calc = chip->buffers.ecccalc;
+        uint8_t *ecc_calc = chip->buffers->ecccalc;
         const uint8_t *p = buf;
         int *eccpos = chip->ecc.layout->eccpos;
 
@@ -1418,7 +1418,7 @@ static void nand_write_page_hwecc(struct mtd_info *mtd, struct nand_chip *chip,
         int i, eccsize = chip->ecc.size;
         int eccbytes = chip->ecc.bytes;
         int eccsteps = chip->ecc.steps;
-        uint8_t *ecc_calc = chip->buffers.ecccalc;
+        uint8_t *ecc_calc = chip->buffers->ecccalc;
         const uint8_t *p = buf;
         int *eccpos = chip->ecc.layout->eccpos;
 
@@ -1628,7 +1628,7 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
             (chip->pagebuf << chip->page_shift) < (to + ops->len))
                 chip->pagebuf = -1;
 
-        chip->oob_poi = chip->buffers.oobwbuf;
+        chip->oob_poi = chip->buffers->oobwbuf;
 
         while(1) {
                 int cached = writelen > bytes && page != blockmask;
@@ -1746,7 +1746,7 @@ static int nand_do_write_oob(struct mtd_info *mtd, loff_t to,
         if (page == chip->pagebuf)
                 chip->pagebuf = -1;
 
-        chip->oob_poi = chip->buffers.oobwbuf;
+        chip->oob_poi = chip->buffers->oobwbuf;
         memset(chip->oob_poi, 0xff, mtd->oobsize);
         nand_fill_oob(chip, ops->oobbuf, ops);
         status = chip->ecc.write_oob(mtd, chip, page & chip->pagemask);
@@ -2354,8 +2354,13 @@ int nand_scan_tail(struct mtd_info *mtd)
         int i;
         struct nand_chip *chip = mtd->priv;
 
+        if (!(chip->options & NAND_OWN_BUFFERS))
+                chip->buffers = kmalloc(sizeof(*chip->buffers), GFP_KERNEL);
+        if (!chip->buffers)
+                return -ENOMEM;
+
         /* Preset the internal oob write buffer */
-        memset(chip->buffers.oobwbuf, 0xff, mtd->oobsize);
+        memset(chip->buffers->oobwbuf, 0xff, mtd->oobsize);
 
         /*
          * If no default placement scheme is given, select an appropriate one
@@ -2559,6 +2564,8 @@ void nand_release(struct mtd_info *mtd)
 
         /* Free bad block table memory */
         kfree(chip->bbt);
+        if (!(chip->options & NAND_OWN_BUFFERS))
+                kfree(chip->buffers);
 }
 
 EXPORT_SYMBOL_GPL(nand_scan);
diff --git a/drivers/mtd/nand/nand_bbt.c b/drivers/mtd/nand/nand_bbt.c
index a612c4ea8194..9402653eb09b 100644
--- a/drivers/mtd/nand/nand_bbt.c
+++ b/drivers/mtd/nand/nand_bbt.c
@@ -759,7 +759,7 @@ static inline int nand_memory_bbt(struct mtd_info *mtd, struct nand_bbt_descr *b
         struct nand_chip *this = mtd->priv;
 
         bd->options &= ~NAND_BBT_SCANEMPTY;
-        return create_bbt(mtd, this->buffers.databuf, bd, -1);
+        return create_bbt(mtd, this->buffers->databuf, bd, -1);
 }
 
 /**
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 88d690d79d77..cd4fe9ae8622 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -183,7 +183,9 @@ typedef enum {
 #define NAND_USE_FLASH_BBT      0x00010000
 /* This option skips the bbt scan during initialization. */
 #define NAND_SKIP_BBTSCAN       0x00020000
-
+/* This option is defined if the board driver allocates its own buffers
+   (e.g. because it needs them DMA-coherent */
+#define NAND_OWN_BUFFERS        0x00040000
 /* Options set by nand scan */
 /* Nand scan has allocated controller struct */
 #define NAND_CONTROLLER_ALLOC   0x80000000
@@ -385,7 +387,7 @@ struct nand_chip {
         struct nand_ecclayout   *ecclayout;
 
         struct nand_ecc_ctrl ecc;
-        struct nand_buffers buffers;
+        struct nand_buffers *buffers;
         struct nand_hw_control hwcontrol;
 
         struct mtd_oob_ops ops;