mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-22 02:24:57 +08:00
683313993d
Cast &data to (char *) in order to avoid unintentionally accessing
the stack.
Notice that data is of type u32, so any increment to &data
will be in the order of 4-byte chunks, and this piece of code
is actually intended to be a byte offset.
Fixes: b3e79e7682 ("mtd: physmap: Add Baikal-T1 physically mapped ROM support")
Addresses-Coverity-ID: 1497765 ("Out-of-bounds access")
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210212104022.GA242669@embeddedor
127 lines
3.0 KiB
C
127 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
|
|
*
|
|
* Authors:
|
|
* Serge Semin <Sergey.Semin@baikalelectronics.ru>
|
|
*
|
|
* Baikal-T1 Physically Mapped Internal ROM driver
|
|
*/
|
|
#include <linux/bits.h>
|
|
#include <linux/device.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/mtd/map.h>
|
|
#include <linux/mtd/xip.h>
|
|
#include <linux/mux/consumer.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_device.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/string.h>
|
|
#include <linux/types.h>
|
|
|
|
#include "physmap-bt1-rom.h"
|
|
|
|
/*
|
|
* Baikal-T1 SoC ROMs are only accessible by the dword-aligned instructions.
|
|
* We have to take this into account when implementing the data read-methods.
|
|
* Note there is no need in bothering with endianness, since both Baikal-T1
|
|
* CPU and MMIO are LE.
|
|
*/
|
|
static map_word __xipram bt1_rom_map_read(struct map_info *map,
|
|
unsigned long ofs)
|
|
{
|
|
void __iomem *src = map->virt + ofs;
|
|
unsigned int shift;
|
|
map_word ret;
|
|
u32 data;
|
|
|
|
/* Read data within offset dword. */
|
|
shift = (uintptr_t)src & 0x3;
|
|
data = readl_relaxed(src - shift);
|
|
if (!shift) {
|
|
ret.x[0] = data;
|
|
return ret;
|
|
}
|
|
ret.x[0] = data >> (shift * BITS_PER_BYTE);
|
|
|
|
/* Read data from the next dword. */
|
|
shift = 4 - shift;
|
|
if (ofs + shift >= map->size)
|
|
return ret;
|
|
|
|
data = readl_relaxed(src + shift);
|
|
ret.x[0] |= data << (shift * BITS_PER_BYTE);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __xipram bt1_rom_map_copy_from(struct map_info *map,
|
|
void *to, unsigned long from,
|
|
ssize_t len)
|
|
{
|
|
void __iomem *src = map->virt + from;
|
|
unsigned int shift, chunk;
|
|
u32 data;
|
|
|
|
if (len <= 0 || from >= map->size)
|
|
return;
|
|
|
|
/* Make sure we don't go over the map limit. */
|
|
len = min_t(ssize_t, map->size - from, len);
|
|
|
|
/*
|
|
* Since requested data size can be pretty big we have to implement
|
|
* the copy procedure as optimal as possible. That's why it's split
|
|
* up into the next three stages: unaligned head, aligned body,
|
|
* unaligned tail.
|
|
*/
|
|
shift = (uintptr_t)src & 0x3;
|
|
if (shift) {
|
|
chunk = min_t(ssize_t, 4 - shift, len);
|
|
data = readl_relaxed(src - shift);
|
|
memcpy(to, (char *)&data + shift, chunk);
|
|
src += chunk;
|
|
to += chunk;
|
|
len -= chunk;
|
|
}
|
|
|
|
while (len >= 4) {
|
|
data = readl_relaxed(src);
|
|
memcpy(to, &data, 4);
|
|
src += 4;
|
|
to += 4;
|
|
len -= 4;
|
|
}
|
|
|
|
if (len) {
|
|
data = readl_relaxed(src);
|
|
memcpy(to, &data, len);
|
|
}
|
|
}
|
|
|
|
int of_flash_probe_bt1_rom(struct platform_device *pdev,
|
|
struct device_node *np,
|
|
struct map_info *map)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
|
|
/* It's supposed to be read-only MTD. */
|
|
if (!of_device_is_compatible(np, "mtd-rom")) {
|
|
dev_info(dev, "No mtd-rom compatible string\n");
|
|
return 0;
|
|
}
|
|
|
|
/* Multiplatform guard. */
|
|
if (!of_device_is_compatible(np, "baikal,bt1-int-rom"))
|
|
return 0;
|
|
|
|
/* Sanity check the device parameters retrieved from DTB. */
|
|
if (map->bankwidth != 4)
|
|
dev_warn(dev, "Bank width is supposed to be 32 bits wide\n");
|
|
|
|
map->read = bt1_rom_map_read;
|
|
map->copy_from = bt1_rom_map_copy_from;
|
|
|
|
return 0;
|
|
}
|