[PATCH] mtd onenand driver: reduce stack usage

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 28 insertions, 7 deletions

diff --git a/drivers/mtd/onenand/onenand_base.c b/drivers/mtd/onenand/onenand_base.c
index d57afbaaedc4..a53a73fc2a5a 100644
--- a/drivers/mtd/onenand/onenand_base.c
+++ b/drivers/mtd/onenand/onenand_base.c
@@ -940,7 +940,7 @@ static int onenand_writev_ecc(struct mtd_info *mtd, const struct kvec *vecs,
         u_char *eccbuf, struct nand_oobinfo *oobsel)
 {
         struct onenand_chip *this = mtd->priv;
-        unsigned char buffer[MAX_ONENAND_PAGESIZE], *pbuf;
+        unsigned char *pbuf;
         size_t total_len, len;
         int i, written = 0;
         int ret = 0;
@@ -975,7 +975,7 @@ static int onenand_writev_ecc(struct mtd_info *mtd, const struct kvec *vecs,
         /* Loop until all keve's data has been written */
         len = 0;
         while (count) {
-                pbuf = buffer;
+                pbuf = this->page_buf;
                 /*
                  * If the given tuple is >= pagesize then
                  * write it out from the iov
@@ -995,7 +995,7 @@ static int onenand_writev_ecc(struct mtd_info *mtd, const struct kvec *vecs,
                         int cnt = 0, thislen;
                         while (cnt < mtd->oobblock) {
                                 thislen = min_t(int, mtd->oobblock - cnt, vecs->iov_len - len);
-                                memcpy(buffer + cnt, vecs->iov_base + len, thislen);
+                                memcpy(this->page_buf + cnt, vecs->iov_base + len, thislen);
                                 cnt += thislen;
                                 len += thislen;
 
@@ -1519,6 +1519,18 @@ int onenand_scan(struct mtd_info *mtd, int maxchips)
                 this->read_bufferram = onenand_sync_read_bufferram;
         }
 
+        /* Allocate buffers, if necessary */
+        if (!this->page_buf) {
+                size_t len;
+                len = mtd->oobblock + mtd->oobsize;
+                this->page_buf = kmalloc(len, GFP_KERNEL);
+                if (!this->page_buf) {
+                        printk(KERN_ERR "onenand_scan(): Can't allocate page_buf\n");
+                        return -ENOMEM;
+                }
+                this->options |= ONENAND_PAGEBUF_ALLOC;
+        }
+
         this->state = FL_READY;
         init_waitqueue_head(&this->wq);
         spin_lock_init(&this->chip_lock);
@@ -1580,12 +1592,21 @@ int onenand_scan(struct mtd_info *mtd, int maxchips)
  */
 void onenand_release(struct mtd_info *mtd)
 {
+        struct onenand_chip *this = mtd->priv;
+
 #ifdef CONFIG_MTD_PARTITIONS
         /* Deregister partitions */
         del_mtd_partitions (mtd);
 #endif
         /* Deregister the device */
         del_mtd_device (mtd);
+
+        /* Free bad block table memory, if allocated */
+        if (this->bbm)
+                kfree(this->bbm);
+        /* Buffer allocated by onenand_scan */
+        if (this->options & ONENAND_PAGEBUF_ALLOC)
+                kfree(this->page_buf);
 }
 
 EXPORT_SYMBOL_GPL(onenand_scan);
diff --git a/drivers/mtd/onenand/onenand_bbt.c b/drivers/mtd/onenand/onenand_bbt.c
index f40190f499e1..4510d3361eaa 100644
--- a/drivers/mtd/onenand/onenand_bbt.c
+++ b/drivers/mtd/onenand/onenand_bbt.c
@@ -118,10 +118,10 @@ static int create_bbt(struct mtd_info *mtd, uint8_t *buf, struct nand_bbt_descr
  */
 static inline int onenand_memory_bbt (struct mtd_info *mtd, struct nand_bbt_descr *bd)
 {
-        unsigned char data_buf[MAX_ONENAND_PAGESIZE];
+        struct onenand_chip *this = mtd->priv;
 
         bd->options &= ~NAND_BBT_SCANEMPTY;
-        return create_bbt(mtd, data_buf, bd, -1);
+        return create_bbt(mtd, this->page_buf, bd, -1);
 }
 
 /**
diff --git a/include/linux/mtd/onenand.h b/include/linux/mtd/onenand.h
index 53423d3b43bf..7419b5fab133 100644
--- a/include/linux/mtd/onenand.h
+++ b/include/linux/mtd/onenand.h
@@ -17,7 +17,6 @@
 #include <linux/mtd/bbm.h>
 
 #define MAX_BUFFERRAM           2
-#define MAX_ONENAND_PAGESIZE    (2048 + 64)
 
 /* Scan and identify a OneNAND device */
 extern int onenand_scan(struct mtd_info *mtd, int max_chips);
@@ -110,6 +109,7 @@ struct onenand_chip {
         spinlock_t              chip_lock;
         wait_queue_head_t       wq;
         onenand_state_t         state;
+        unsigned char           *page_buf;
 
         struct nand_oobinfo     *autooob;
 
@@ -134,7 +134,7 @@ struct onenand_chip {
  * Options bits
  */
 #define ONENAND_CONT_LOCK               (0x0001)
-
+#define ONENAND_PAGEBUF_ALLOC           (0x1000)
 
 /*
  * OneNAND Flash Manufacturer ID Codes