Commit 477544c6 authored by Masahiro Yamada's avatar Masahiro Yamada Committed by Boris Brezillon

mtd: nand: allow drivers to request minimum alignment for passed buffer

In some cases, nand_do_{read,write}_ops is passed with unaligned
ops->datbuf.  Drivers using DMA will be unhappy about unaligned
buffer.

The new struct member, buf_align, represents the minimum alignment
the driver require for the buffer.  If the buffer passed from the
upper MTD layer does not have enough alignment, nand_do_*_ops will
use bufpoi.
Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@free-electrons.com>
parent 3deb9979
......@@ -1954,7 +1954,9 @@ static int nand_do_read_ops(struct mtd_info *mtd, loff_t from,
if (!aligned)
use_bufpoi = 1;
else if (chip->options & NAND_USE_BOUNCE_BUFFER)
use_bufpoi = !virt_addr_valid(buf);
use_bufpoi = !virt_addr_valid(buf) ||
!IS_ALIGNED((unsigned long)buf,
chip->buf_align);
else
use_bufpoi = 0;
......@@ -2810,7 +2812,9 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to,
if (part_pagewr)
use_bufpoi = 1;
else if (chip->options & NAND_USE_BOUNCE_BUFFER)
use_bufpoi = !virt_addr_valid(buf);
use_bufpoi = !virt_addr_valid(buf) ||
!IS_ALIGNED((unsigned long)buf,
chip->buf_align);
else
use_bufpoi = 0;
......@@ -3429,6 +3433,8 @@ static void nand_set_defaults(struct nand_chip *chip)
nand_hw_control_init(chip->controller);
}
if (!chip->buf_align)
chip->buf_align = 1;
}
/* Sanitize ONFI strings so we can safely print them */
......
......@@ -755,6 +755,7 @@ struct nand_manufacturer_ops {
* setting the read-retry mode. Mostly needed for MLC NAND.
* @ecc: [BOARDSPECIFIC] ECC control structure
* @buffers: buffer structure for read/write
* @buf_align: minimum buffer alignment required by a platform
* @hwcontrol: platform-specific hardware control structure
* @erase: [REPLACEABLE] erase function
* @scan_bbt: [REPLACEABLE] function to scan bad block table
......@@ -905,6 +906,7 @@ struct nand_chip {
struct nand_ecc_ctrl ecc;
struct nand_buffers *buffers;
unsigned long buf_align;
struct nand_hw_control hwcontrol;
uint8_t *bbt;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment