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u-boot/drivers/core/regmap.c
Marek Behún 364bef150d regmap: fix a serious pointer casting bug 
There is a serious bug in regmap_read() and regmap_write() functions
where an uint pointer is cast to (void *) which is then cast to (u8 *),
(u16 *), (u32 *) or (u64 *), depending on register width of the map.

For example given a regmap with 16-bit register width the code
	int val = 0x12340000;
	regmap_read(map, 0, &val);
only changes the lower 16 bits of val on little-endian machines.
The upper 16 bits will remain 0x1234.

Nobody noticed this probably because this bug can be triggered with
regmap_write() only on big-endian architectures (which are not used by
many people anymore), and on little endian this bug has consequences
only if register width is 8 or 16 bits and also the memory place to
which regmap_read() should store it's result has non-zero upper bits,
which it seems doesn't happen anywhere in U-Boot normally. CI managed to
trigger this bug in unit test of dm_test_devm_regmap_field when compiled
for sandbox_defconfig using LTO.

Fix this by utilizing an union { u8; u16; u32; u64; } and reading data
into this union / writing data from this union.

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Cc: Simon Glass <sjg@chromium.org>
Cc: Heiko Schocher <hs@denx.de>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Pratyush Yadav <p.yadav@ti.com>
2021-05-24 14:21:30 -04:00

688 lines
15 KiB
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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <log.h>
#include <asm/global_data.h>
#include <linux/libfdt.h>
#include <malloc.h>
#include <mapmem.h>
#include <regmap.h>
#include <asm/io.h>
#include <dm/of_addr.h>
#include <dm/devres.h>
#include <linux/ioport.h>
#include <linux/compat.h>
#include <linux/err.h>
#include <linux/bitops.h>
/*
* Internal representation of a regmap field. Instead of storing the MSB and
* LSB, store the shift and mask. This makes the code a bit cleaner and faster
* because the shift and mask don't have to be calculated every time.
*/
struct regmap_field {
struct regmap *regmap;
unsigned int mask;
/* lsb */
unsigned int shift;
unsigned int reg;
};
DECLARE_GLOBAL_DATA_PTR;
/**
* regmap_alloc() - Allocate a regmap with a given number of ranges.
*
* @count: Number of ranges to be allocated for the regmap.
*
* The default regmap width is set to REGMAP_SIZE_32. Callers can override it
* if they need.
*
* Return: A pointer to the newly allocated regmap, or NULL on error.
*/
static struct regmap *regmap_alloc(int count)
{
struct regmap *map;
size_t size = sizeof(*map) + sizeof(map->ranges[0]) * count;
map = calloc(1, size);
if (!map)
return NULL;
map->range_count = count;
map->width = REGMAP_SIZE_32;
return map;
}
#if CONFIG_IS_ENABLED(OF_PLATDATA)
int regmap_init_mem_plat(struct udevice *dev, fdt_val_t *reg, int count,
struct regmap **mapp)
{
struct regmap_range *range;
struct regmap *map;
map = regmap_alloc(count);
if (!map)
return -ENOMEM;
for (range = map->ranges; count > 0; reg += 2, range++, count--) {
range->start = *reg;
range->size = reg[1];
}
*mapp = map;
return 0;
}
#else
/**
* init_range() - Initialize a single range of a regmap
* @node: Device node that will use the map in question
* @range: Pointer to a regmap_range structure that will be initialized
* @addr_len: The length of the addr parts of the reg property
* @size_len: The length of the size parts of the reg property
* @index: The index of the range to initialize
*
* This function will read the necessary 'reg' information from the device tree
* (the 'addr' part, and the 'length' part), and initialize the range in
* quesion.
*
* Return: 0 if OK, -ve on error
*/
static int init_range(ofnode node, struct regmap_range *range, int addr_len,
int size_len, int index)
{
fdt_size_t sz;
struct resource r;
if (of_live_active()) {
int ret;
ret = of_address_to_resource(ofnode_to_np(node),
index, &r);
if (ret) {
debug("%s: Could not read resource of range %d (ret = %d)\n",
ofnode_get_name(node), index, ret);
return ret;
}
range->start = r.start;
range->size = r.end - r.start + 1;
} else {
int offset = ofnode_to_offset(node);
range->start = fdtdec_get_addr_size_fixed(gd->fdt_blob, offset,
"reg", index,
addr_len, size_len,
&sz, true);
if (range->start == FDT_ADDR_T_NONE) {
debug("%s: Could not read start of range %d\n",
ofnode_get_name(node), index);
return -EINVAL;
}
range->size = sz;
}
return 0;
}
int regmap_init_mem_index(ofnode node, struct regmap **mapp, int index)
{
struct regmap *map;
int addr_len, size_len;
int ret;
addr_len = ofnode_read_simple_addr_cells(ofnode_get_parent(node));
if (addr_len < 0) {
debug("%s: Error while reading the addr length (ret = %d)\n",
ofnode_get_name(node), addr_len);
return addr_len;
}
size_len = ofnode_read_simple_size_cells(ofnode_get_parent(node));
if (size_len < 0) {
debug("%s: Error while reading the size length: (ret = %d)\n",
ofnode_get_name(node), size_len);
return size_len;
}
map = regmap_alloc(1);
if (!map)
return -ENOMEM;
ret = init_range(node, map->ranges, addr_len, size_len, index);
if (ret)
goto err;
if (ofnode_read_bool(node, "little-endian"))
map->endianness = REGMAP_LITTLE_ENDIAN;
else if (ofnode_read_bool(node, "big-endian"))
map->endianness = REGMAP_BIG_ENDIAN;
else if (ofnode_read_bool(node, "native-endian"))
map->endianness = REGMAP_NATIVE_ENDIAN;
else /* Default: native endianness */
map->endianness = REGMAP_NATIVE_ENDIAN;
*mapp = map;
return 0;
err:
regmap_uninit(map);
return ret;
}
int regmap_init_mem_range(ofnode node, ulong r_start, ulong r_size,
struct regmap **mapp)
{
struct regmap *map;
struct regmap_range *range;
map = regmap_alloc(1);
if (!map)
return -ENOMEM;
range = &map->ranges[0];
range->start = r_start;
range->size = r_size;
if (ofnode_read_bool(node, "little-endian"))
map->endianness = REGMAP_LITTLE_ENDIAN;
else if (ofnode_read_bool(node, "big-endian"))
map->endianness = REGMAP_BIG_ENDIAN;
else if (ofnode_read_bool(node, "native-endian"))
map->endianness = REGMAP_NATIVE_ENDIAN;
else /* Default: native endianness */
map->endianness = REGMAP_NATIVE_ENDIAN;
*mapp = map;
return 0;
}
int regmap_init_mem(ofnode node, struct regmap **mapp)
{
struct regmap_range *range;
struct regmap *map;
int count;
int addr_len, size_len, both_len;
int len;
int index;
int ret;
addr_len = ofnode_read_simple_addr_cells(ofnode_get_parent(node));
if (addr_len < 0) {
debug("%s: Error while reading the addr length (ret = %d)\n",
ofnode_get_name(node), addr_len);
return addr_len;
}
size_len = ofnode_read_simple_size_cells(ofnode_get_parent(node));
if (size_len < 0) {
debug("%s: Error while reading the size length: (ret = %d)\n",
ofnode_get_name(node), size_len);
return size_len;
}
both_len = addr_len + size_len;
if (!both_len) {
debug("%s: Both addr and size length are zero\n",
ofnode_get_name(node));
return -EINVAL;
}
len = ofnode_read_size(node, "reg");
if (len < 0) {
debug("%s: Error while reading reg size (ret = %d)\n",
ofnode_get_name(node), len);
return len;
}
len /= sizeof(fdt32_t);
count = len / both_len;
if (!count) {
debug("%s: Not enough data in reg property\n",
ofnode_get_name(node));
return -EINVAL;
}
map = regmap_alloc(count);
if (!map)
return -ENOMEM;
for (range = map->ranges, index = 0; count > 0;
count--, range++, index++) {
ret = init_range(node, range, addr_len, size_len, index);
if (ret)
goto err;
}
if (ofnode_read_bool(node, "little-endian"))
map->endianness = REGMAP_LITTLE_ENDIAN;
else if (ofnode_read_bool(node, "big-endian"))
map->endianness = REGMAP_BIG_ENDIAN;
else if (ofnode_read_bool(node, "native-endian"))
map->endianness = REGMAP_NATIVE_ENDIAN;
else /* Default: native endianness */
map->endianness = REGMAP_NATIVE_ENDIAN;
*mapp = map;
return 0;
err:
regmap_uninit(map);
return ret;
}
static void devm_regmap_release(struct udevice *dev, void *res)
{
regmap_uninit(*(struct regmap **)res);
}
struct regmap *devm_regmap_init(struct udevice *dev,
const struct regmap_bus *bus,
void *bus_context,
const struct regmap_config *config)
{
int rc;
struct regmap **mapp, *map;
mapp = devres_alloc(devm_regmap_release, sizeof(struct regmap *),
__GFP_ZERO);
if (unlikely(!mapp))
return ERR_PTR(-ENOMEM);
if (config && config->r_size != 0)
rc = regmap_init_mem_range(dev_ofnode(dev), config->r_start,
config->r_size, mapp);
else
rc = regmap_init_mem(dev_ofnode(dev), mapp);
if (rc)
return ERR_PTR(rc);
map = *mapp;
if (config) {
map->width = config->width;
map->reg_offset_shift = config->reg_offset_shift;
}
devres_add(dev, mapp);
return *mapp;
}
#endif
void *regmap_get_range(struct regmap *map, unsigned int range_num)
{
struct regmap_range *range;
if (range_num >= map->range_count)
return NULL;
range = &map->ranges[range_num];
return map_sysmem(range->start, range->size);
}
int regmap_uninit(struct regmap *map)
{
free(map);
return 0;
}
static inline u8 __read_8(u8 *addr, enum regmap_endianness_t endianness)
{
return readb(addr);
}
static inline u16 __read_16(u16 *addr, enum regmap_endianness_t endianness)
{
switch (endianness) {
case REGMAP_LITTLE_ENDIAN:
return in_le16(addr);
case REGMAP_BIG_ENDIAN:
return in_be16(addr);
case REGMAP_NATIVE_ENDIAN:
return readw(addr);
}
return readw(addr);
}
static inline u32 __read_32(u32 *addr, enum regmap_endianness_t endianness)
{
switch (endianness) {
case REGMAP_LITTLE_ENDIAN:
return in_le32(addr);
case REGMAP_BIG_ENDIAN:
return in_be32(addr);
case REGMAP_NATIVE_ENDIAN:
return readl(addr);
}
return readl(addr);
}
#if defined(in_le64) && defined(in_be64) && defined(readq)
static inline u64 __read_64(u64 *addr, enum regmap_endianness_t endianness)
{
switch (endianness) {
case REGMAP_LITTLE_ENDIAN:
return in_le64(addr);
case REGMAP_BIG_ENDIAN:
return in_be64(addr);
case REGMAP_NATIVE_ENDIAN:
return readq(addr);
}
return readq(addr);
}
#endif
int regmap_raw_read_range(struct regmap *map, uint range_num, uint offset,
void *valp, size_t val_len)
{
struct regmap_range *range;
void *ptr;
if (range_num >= map->range_count) {
debug("%s: range index %d larger than range count\n",
__func__, range_num);
return -ERANGE;
}
range = &map->ranges[range_num];
offset <<= map->reg_offset_shift;
if (offset + val_len > range->size) {
debug("%s: offset/size combination invalid\n", __func__);
return -ERANGE;
}
ptr = map_physmem(range->start + offset, val_len, MAP_NOCACHE);
switch (val_len) {
case REGMAP_SIZE_8:
*((u8 *)valp) = __read_8(ptr, map->endianness);
break;
case REGMAP_SIZE_16:
*((u16 *)valp) = __read_16(ptr, map->endianness);
break;
case REGMAP_SIZE_32:
*((u32 *)valp) = __read_32(ptr, map->endianness);
break;
#if defined(in_le64) && defined(in_be64) && defined(readq)
case REGMAP_SIZE_64:
*((u64 *)valp) = __read_64(ptr, map->endianness);
break;
#endif
default:
debug("%s: regmap size %zu unknown\n", __func__, val_len);
return -EINVAL;
}
return 0;
}
int regmap_raw_read(struct regmap *map, uint offset, void *valp, size_t val_len)
{
return regmap_raw_read_range(map, 0, offset, valp, val_len);
}
int regmap_read(struct regmap *map, uint offset, uint *valp)
{
union {
u8 v8;
u16 v16;
u32 v32;
u64 v64;
} u;
int res;
res = regmap_raw_read(map, offset, &u, map->width);
if (res)
return res;
switch (map->width) {
case REGMAP_SIZE_8:
*valp = u.v8;
break;
case REGMAP_SIZE_16:
*valp = u.v16;
break;
case REGMAP_SIZE_32:
*valp = u.v32;
break;
case REGMAP_SIZE_64:
*valp = u.v64;
break;
default:
unreachable();
}
return 0;
}
static inline void __write_8(u8 *addr, const u8 *val,
enum regmap_endianness_t endianness)
{
writeb(*val, addr);
}
static inline void __write_16(u16 *addr, const u16 *val,
enum regmap_endianness_t endianness)
{
switch (endianness) {
case REGMAP_NATIVE_ENDIAN:
writew(*val, addr);
break;
case REGMAP_LITTLE_ENDIAN:
out_le16(addr, *val);
break;
case REGMAP_BIG_ENDIAN:
out_be16(addr, *val);
break;
}
}
static inline void __write_32(u32 *addr, const u32 *val,
enum regmap_endianness_t endianness)
{
switch (endianness) {
case REGMAP_NATIVE_ENDIAN:
writel(*val, addr);
break;
case REGMAP_LITTLE_ENDIAN:
out_le32(addr, *val);
break;
case REGMAP_BIG_ENDIAN:
out_be32(addr, *val);
break;
}
}
#if defined(out_le64) && defined(out_be64) && defined(writeq)
static inline void __write_64(u64 *addr, const u64 *val,
enum regmap_endianness_t endianness)
{
switch (endianness) {
case REGMAP_NATIVE_ENDIAN:
writeq(*val, addr);
break;
case REGMAP_LITTLE_ENDIAN:
out_le64(addr, *val);
break;
case REGMAP_BIG_ENDIAN:
out_be64(addr, *val);
break;
}
}
#endif
int regmap_raw_write_range(struct regmap *map, uint range_num, uint offset,
const void *val, size_t val_len)
{
struct regmap_range *range;
void *ptr;
if (range_num >= map->range_count) {
debug("%s: range index %d larger than range count\n",
__func__, range_num);
return -ERANGE;
}
range = &map->ranges[range_num];
offset <<= map->reg_offset_shift;
if (offset + val_len > range->size) {
debug("%s: offset/size combination invalid\n", __func__);
return -ERANGE;
}
ptr = map_physmem(range->start + offset, val_len, MAP_NOCACHE);
switch (val_len) {
case REGMAP_SIZE_8:
__write_8(ptr, val, map->endianness);
break;
case REGMAP_SIZE_16:
__write_16(ptr, val, map->endianness);
break;
case REGMAP_SIZE_32:
__write_32(ptr, val, map->endianness);
break;
#if defined(out_le64) && defined(out_be64) && defined(writeq)
case REGMAP_SIZE_64:
__write_64(ptr, val, map->endianness);
break;
#endif
default:
debug("%s: regmap size %zu unknown\n", __func__, val_len);
return -EINVAL;
}
return 0;
}
int regmap_raw_write(struct regmap *map, uint offset, const void *val,
size_t val_len)
{
return regmap_raw_write_range(map, 0, offset, val, val_len);
}
int regmap_write(struct regmap *map, uint offset, uint val)
{
union {
u8 v8;
u16 v16;
u32 v32;
u64 v64;
} u;
switch (map->width) {
case REGMAP_SIZE_8:
u.v8 = val;
break;
case REGMAP_SIZE_16:
u.v16 = val;
break;
case REGMAP_SIZE_32:
u.v32 = val;
break;
case REGMAP_SIZE_64:
u.v64 = val;
break;
default:
debug("%s: regmap size %zu unknown\n", __func__,
(size_t)map->width);
return -EINVAL;
}
return regmap_raw_write(map, offset, &u, map->width);
}
int regmap_update_bits(struct regmap *map, uint offset, uint mask, uint val)
{
uint reg;
int ret;
ret = regmap_read(map, offset, &reg);
if (ret)
return ret;
reg &= ~mask;
return regmap_write(map, offset, reg | (val & mask));
}
int regmap_field_read(struct regmap_field *field, unsigned int *val)
{
int ret;
unsigned int reg_val;
ret = regmap_read(field->regmap, field->reg, &reg_val);
if (ret != 0)
return ret;
reg_val &= field->mask;
reg_val >>= field->shift;
*val = reg_val;
return ret;
}
int regmap_field_write(struct regmap_field *field, unsigned int val)
{
return regmap_update_bits(field->regmap, field->reg, field->mask,
val << field->shift);
}
static void regmap_field_init(struct regmap_field *rm_field,
struct regmap *regmap,
struct reg_field reg_field)
{
rm_field->regmap = regmap;
rm_field->reg = reg_field.reg;
rm_field->shift = reg_field.lsb;
rm_field->mask = GENMASK(reg_field.msb, reg_field.lsb);
}
struct regmap_field *devm_regmap_field_alloc(struct udevice *dev,
struct regmap *regmap,
struct reg_field reg_field)
{
struct regmap_field *rm_field = devm_kzalloc(dev, sizeof(*rm_field),
GFP_KERNEL);
if (!rm_field)
return ERR_PTR(-ENOMEM);
regmap_field_init(rm_field, regmap, reg_field);
return rm_field;
}
void devm_regmap_field_free(struct udevice *dev, struct regmap_field *field)
{
devm_kfree(dev, field);
}
struct regmap_field *regmap_field_alloc(struct regmap *regmap,
struct reg_field reg_field)
{
struct regmap_field *rm_field = kzalloc(sizeof(*rm_field), GFP_KERNEL);
if (!rm_field)
return ERR_PTR(-ENOMEM);
regmap_field_init(rm_field, regmap, reg_field);
return rm_field;
}
void regmap_field_free(struct regmap_field *field)
{
kfree(field);
}
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