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Subject[PATCH 5/7] mtd: spi_nor: pass DMA-able buffer to spi_nor_read_raw()
Date
spi_nor_read_raw() calls nor->read() which might be implemented
by the m25p80 driver. m25p80 uses the spi-mem layer which requires
DMA-able in/out buffers. Pass kmalloc'ed dma buffer to spi_nor_read_raw().

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
---
drivers/mtd/spi-nor/spi-nor.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 79ca1102faed..2eaa21c85483 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -2161,7 +2161,7 @@ spi_nor_set_pp_settings(struct spi_nor_pp_command *pp,
* @nor: pointer to a 'struct spi_nor'
* @addr: offset in the serial flash memory
* @len: number of bytes to read
- * @buf: buffer where the data is copied into
+ * @buf: buffer where the data is copied into (dma-safe memory)
*
* Return: 0 on success, -errno otherwise.
*/
@@ -2868,11 +2868,16 @@ static const u32 *spi_nor_get_map_in_use(struct spi_nor *nor, const u32 *smpt,
u8 smpt_len)
{
const u32 *ret;
+ u8 *dma_safe;
u32 addr;
int err;
u8 i, ncmds, nmaps;
u8 addr_width, read_opcode, read_dummy;
- u8 read_data_mask, data_byte, map_id;
+ u8 read_data_mask, map_id;
+
+ dma_safe = kmalloc(sizeof(*dma_safe), GFP_KERNEL | GFP_DMA);
+ if (!dma_safe)
+ return ERR_PTR(-ENOMEM);

addr_width = nor->addr_width;
read_dummy = nor->read_dummy;
@@ -2890,7 +2895,7 @@ static const u32 *spi_nor_get_map_in_use(struct spi_nor *nor, const u32 *smpt,
nor->read_opcode = SMPT_CMD_OPCODE(smpt[i]);
addr = smpt[i + 1];

- err = spi_nor_read_raw(nor, addr, 1, &data_byte);
+ err = spi_nor_read_raw(nor, addr, 1, dma_safe);
if (err) {
ret = ERR_PTR(err);
goto out;
@@ -2900,7 +2905,7 @@ static const u32 *spi_nor_get_map_in_use(struct spi_nor *nor, const u32 *smpt,
* Build an index value that is used to select the Sector Map
* Configuration that is currently in use.
*/
- map_id = map_id << 1 | !!(data_byte & read_data_mask);
+ map_id = map_id << 1 | !!(*dma_safe & read_data_mask);
ncmds++;
}

@@ -2941,6 +2946,7 @@ static const u32 *spi_nor_get_map_in_use(struct spi_nor *nor, const u32 *smpt,

/* fall through */
out:
+ kfree(dma_safe);
nor->addr_width = addr_width;
nor->read_dummy = read_dummy;
nor->read_opcode = read_opcode;
--
2.9.4
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