Commit 4a3e85f2 authored by Boris Brezillon's avatar Boris Brezillon
Browse files

mtd: devices: m25p80: Make sure the buffer passed in op is DMA-able 



As documented in spi-mem.h, spi_mem_op->data.buf.{in,out} must be
DMA-able, and commit 4120f8d1 ("mtd: spi-nor: Use the spi_mem_xx()
API") failed to follow this rule as buffers passed to
->{read,write}_reg() are usually placed on the stack.

Fix that by allocating a scratch buffer and copying the data around.

Fixes: 4120f8d1 ("mtd: spi-nor: Use the spi_mem_xx() API")
Reported-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@bootlin.com>
Tested-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
parent 85516a98

drivers/mtd/devices/m25p80.c

+23 −3
Original line number Diff line number Diff line
@@ -39,13 +39,23 @@ static int m25p80_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len) 
	struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(code, 1),

					  SPI_MEM_OP_NO_ADDR,

					  SPI_MEM_OP_NO_DUMMY,

					  SPI_MEM_OP_DATA_IN(len, val, 1));

					  SPI_MEM_OP_DATA_IN(len, NULL, 1));

	void *scratchbuf;

	int ret;



	scratchbuf = kmalloc(len, GFP_KERNEL);

	if (!scratchbuf)

		return -ENOMEM;



	op.data.buf.in = scratchbuf;

	ret = spi_mem_exec_op(flash->spimem, &op);

	if (ret < 0)

		dev_err(&flash->spimem->spi->dev, "error %d reading %x\n", ret,

			code);

	else

		memcpy(val, scratchbuf, len);



	kfree(scratchbuf);



	return ret;

}
@@ -56,9 +66,19 @@ static int m25p80_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len) 
	struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(opcode, 1),

					  SPI_MEM_OP_NO_ADDR,

					  SPI_MEM_OP_NO_DUMMY,

					  SPI_MEM_OP_DATA_OUT(len, buf, 1));

					  SPI_MEM_OP_DATA_OUT(len, NULL, 1));

	void *scratchbuf;

	int ret;



	return spi_mem_exec_op(flash->spimem, &op);

	scratchbuf = kmemdup(buf, len, GFP_KERNEL);

	if (!scratchbuf)

		return -ENOMEM;



	op.data.buf.out = scratchbuf;

	ret = spi_mem_exec_op(flash->spimem, &op);

	kfree(scratchbuf);



	return ret;

}



static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,

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