mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-14 06:35:12 +00:00
18b9c94037
sparse is unhappy with us casting the __iomem address space pointer to
a type with no address space attribute specified:
"sparse warnings: (new ones prefixed by >>)"
>> drivers/mtd/maps/physmap-bt1-rom.c:78:18: sparse: sparse: cast removes address space '__iomem' of expression
Indeed we perform the __iomem-less type casting but to an integer
variable. The integer variable isn't dereferenced then, so the casting is
safe and won't cause any problem. But in order to make sparse happy and
keep the code coherent let's fix the warning by converting the local
"shift" and "chunk" variables to the "unsigned int" type (since their
value won't ever exceed three) and cast the __iomem-pointers to uintptr_t.
Add the same fix to the bt1_rom_map_read() method for unification.
Fixes: b3e79e7682 ("mtd: physmap: Add Baikal-T1 physically mapped ROM support")
Link: https://lore.kernel.org/lkml/202011021254.XC70BaQT-lkp@intel.com/
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20201125072640.23516-1-Sergey.Semin@baikalelectronics.ru
126 lines
2.9 KiB
C
126 lines
2.9 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, &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;
|
|
}
|