[PATCH 2/4] mtd: denali: kill the NAND_MAX_PAGESIZE/NAND_MAX_OOBSIZE

Huang Shijie
2013-12-20T16:02:28Z

This patch kills the NAND_MAX_PAGESIZE/NAND_MAX_OOBSIZE by the following
way:
1.) change the @buf field of nand_buf{} from an array to a pointer.
also remove the DENALI_BUF_SIZE macro.

2.) Before we call the nand_scan_ident, we allocate a temporary buffer
whose size is PAGE_SIZE.

3.) After we finish the nand_scan_ident, we have already getten the
page size and oob size. We will allocate the right buffer size
again.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
---
drivers/mtd/nand/denali.c | 51 ++++++++++++++++++++++++++++-------------------
drivers/mtd/nand/denali.h | 4 +---
2 files changed, 31 insertions(+), 24 deletions(-)

diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
index 3a3a47f..c07cd57 100644
--- a/drivers/mtd/nand/denali.c
+++ b/drivers/mtd/nand/denali.c
@@ -125,7 +125,6 @@ static void reset_buf(struct denali_nand_info *denali)

static void write_byte_to_buf(struct denali_nand_info *denali, uint8_t byte)
{
- BUG_ON(denali->buf.tail >= sizeof(denali->buf.buf));
denali->buf.buf[denali->buf.tail++] = byte;
}

@@ -1429,20 +1428,12 @@ int denali_init(struct denali_nand_info *denali)
}
}

- /* Is 32-bit DMA supported? */
- ret = dma_set_mask(denali->dev, DMA_BIT_MASK(32));
- if (ret) {
- pr_err("Spectra: no usable DMA configuration\n");
- return ret;
- }
- denali->buf.dma_buf = dma_map_single(denali->dev, denali->buf.buf,
- DENALI_BUF_SIZE,
- DMA_BIDIRECTIONAL);
+ /* allocate a temporary buffer for nand_scan_ident() */
+ denali->buf.buf = devm_kzalloc(denali->dev, PAGE_SIZE,
+ GFP_DMA | GFP_KERNEL);
+ if (!denali->buf.buf)
+ return -ENOMEM;

- if (dma_mapping_error(denali->dev, denali->buf.dma_buf)) {
- dev_err(denali->dev, "Spectra: failed to map DMA buffer\n");
- return -EIO;
- }
denali->mtd.dev.parent = denali->dev;
denali_hw_init(denali);
denali_drv_init(denali);
@@ -1475,12 +1466,29 @@ int denali_init(struct denali_nand_info *denali)
goto failed_req_irq;
}

- /* MTD supported page sizes vary by kernel. We validate our
- * kernel supports the device here.
- */
- if (denali->mtd.writesize > NAND_MAX_PAGESIZE + NAND_MAX_OOBSIZE) {
- ret = -ENODEV;
- pr_err("Spectra: device size not supported by this version of MTD.");
+ /* allocate the right size buffer now */
+ devm_kfree(denali->dev, denali->buf.buf);
+ denali->buf.buf = devm_kzalloc(denali->dev,
+ denali->mtd.writesize + denali->mtd.oobsize,
+ GFP_KERNEL);
+ if (!denali->buf.buf) {
+ ret = -ENOMEM;
+ goto failed_req_irq;
+ }
+
+ /* Is 32-bit DMA supported? */
+ ret = dma_set_mask(denali->dev, DMA_BIT_MASK(32));
+ if (ret) {
+ pr_err("Spectra: no usable DMA configuration\n");
+ goto failed_req_irq;
+ }
+
+ denali->buf.dma_buf = dma_map_single(denali->dev, denali->buf.buf,
+ denali->mtd.writesize + denali->mtd.oobsize,
+ DMA_BIDIRECTIONAL);
+ if (dma_mapping_error(denali->dev, denali->buf.dma_buf)) {
+ dev_err(denali->dev, "Spectra: failed to map DMA buffer\n");
+ ret = -EIO;
goto failed_req_irq;
}

@@ -1602,7 +1610,8 @@ EXPORT_SYMBOL(denali_init);
void denali_remove(struct denali_nand_info *denali)
{
denali_irq_cleanup(denali->irq, denali);
- dma_unmap_single(denali->dev, denali->buf.dma_buf, DENALI_BUF_SIZE,
+ dma_unmap_single(denali->dev, denali->buf.dma_buf,
+ denali->mtd.writesize + denali->mtd.oobsize,
DMA_BIDIRECTIONAL);
}
EXPORT_SYMBOL(denali_remove);
diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
index cec5712..9668174 100644
--- a/drivers/mtd/nand/denali.h
+++ b/drivers/mtd/nand/denali.h
@@ -455,12 +455,10 @@

#define ECC_SECTOR_SIZE 512

-#define DENALI_BUF_SIZE (NAND_MAX_PAGESIZE + NAND_MAX_OOBSIZE)
-
struct nand_buf {
int head;
int tail;
- uint8_t buf[DENALI_BUF_SIZE];
+ uint8_t *buf;
dma_addr_t dma_buf;
};

--
1.8.3.1