linux/drivers/base/regmap/internal.h

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Register map access API internal header
*
* Copyright 2011 Wolfson Microelectronics plc
*
* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
*/
#ifndef _REGMAP_INTERNAL_H
#define _REGMAP_INTERNAL_H
#include <linux/device.h>
#include <linux/regmap.h>
#include <linux/fs.h>
#include <linux/list.h>
#include <linux/wait.h>
struct regmap;
struct regcache_ops;
struct regmap_debugfs_off_cache {
struct list_head list;
off_t min;
off_t max;
unsigned int base_reg;
unsigned int max_reg;
};
struct regmap_format {
size_t buf_size;
size_t reg_bytes;
size_t pad_bytes;
size_t val_bytes;
void (*format_write)(struct regmap *map,
unsigned int reg, unsigned int val);
void (*format_reg)(void *buf, unsigned int reg, unsigned int shift);
void (*format_val)(void *buf, unsigned int val, unsigned int shift);
unsigned int (*parse_val)(const void *buf);
void (*parse_inplace)(void *buf);
};
struct regmap_async {
struct list_head list;
struct regmap *map;
void *work_buf;
};
struct regmap {
union {
struct mutex mutex;
struct {
spinlock_t spinlock;
unsigned long spinlock_flags;
};
struct {
raw_spinlock_t raw_spinlock;
unsigned long raw_spinlock_flags;
};
};
regmap_lock lock;
regmap_unlock unlock;
void *lock_arg; /* This is passed to lock/unlock functions */
gfp_t alloc_flags;
struct device *dev; /* Device we do I/O on */
void *work_buf; /* Scratch buffer used to format I/O */
struct regmap_format format; /* Buffer format */
const struct regmap_bus *bus;
void *bus_context;
const char *name;
bool async;
spinlock_t async_lock;
wait_queue_head_t async_waitq;
struct list_head async_list;
struct list_head async_free;
int async_ret;
#ifdef CONFIG_DEBUG_FS
bool debugfs_disable;
struct dentry *debugfs;
const char *debugfs_name;
unsigned int debugfs_reg_len;
unsigned int debugfs_val_len;
unsigned int debugfs_tot_len;
struct list_head debugfs_off_cache;
struct mutex cache_lock;
#endif
unsigned int max_register;
bool (*writeable_reg)(struct device *dev, unsigned int reg);
bool (*readable_reg)(struct device *dev, unsigned int reg);
bool (*volatile_reg)(struct device *dev, unsigned int reg);
bool (*precious_reg)(struct device *dev, unsigned int reg);
bool (*writeable_noinc_reg)(struct device *dev, unsigned int reg);
bool (*readable_noinc_reg)(struct device *dev, unsigned int reg);
const struct regmap_access_table *wr_table;
const struct regmap_access_table *rd_table;
const struct regmap_access_table *volatile_table;
const struct regmap_access_table *precious_table;
const struct regmap_access_table *wr_noinc_table;
const struct regmap_access_table *rd_noinc_table;
int (*reg_read)(void *context, unsigned int reg, unsigned int *val);
int (*reg_write)(void *context, unsigned int reg, unsigned int val);
int (*reg_update_bits)(void *context, unsigned int reg,
unsigned int mask, unsigned int val);
bool defer_caching;
unsigned long read_flag_mask;
unsigned long write_flag_mask;
/* number of bits to (left) shift the reg value when formatting*/
int reg_shift;
int reg_stride;
int reg_stride_order;
/* regcache specific members */
const struct regcache_ops *cache_ops;
enum regcache_type cache_type;
/* number of bytes in reg_defaults_raw */
unsigned int cache_size_raw;
/* number of bytes per word in reg_defaults_raw */
unsigned int cache_word_size;
/* number of entries in reg_defaults */
unsigned int num_reg_defaults;
/* number of entries in reg_defaults_raw */
unsigned int num_reg_defaults_raw;
/* if set, only the cache is modified not the HW */
bool cache_only;
/* if set, only the HW is modified not the cache */
bool cache_bypass;
/* if set, remember to free reg_defaults_raw */
bool cache_free;
struct reg_default *reg_defaults;
const void *reg_defaults_raw;
void *cache;
/* if set, the cache contains newer data than the HW */
bool cache_dirty;
/* if set, the HW registers are known to match map->reg_defaults */
bool no_sync_defaults;
struct reg_sequence *patch;
int patch_regs;
/* if set, converts bulk read to single read */
bool use_single_read;
/* if set, converts bulk write to single write */
bool use_single_write;
/* if set, the device supports multi write mode */
bool can_multi_write;
/* if set, raw reads/writes are limited to this size */
size_t max_raw_read;
size_t max_raw_write;
struct rb_root range_tree;
void *selector_work_buf; /* Scratch buffer used for selector */
struct hwspinlock *hwlock;
/* if set, the regmap core can sleep */
bool can_sleep;
};
struct regcache_ops {
const char *name;
enum regcache_type type;
int (*init)(struct regmap *map);
int (*exit)(struct regmap *map);
#ifdef CONFIG_DEBUG_FS
void (*debugfs_init)(struct regmap *map);
#endif
int (*read)(struct regmap *map, unsigned int reg, unsigned int *value);
int (*write)(struct regmap *map, unsigned int reg, unsigned int value);
int (*sync)(struct regmap *map, unsigned int min, unsigned int max);
int (*drop)(struct regmap *map, unsigned int min, unsigned int max);
};
bool regmap_cached(struct regmap *map, unsigned int reg);
bool regmap_writeable(struct regmap *map, unsigned int reg);
bool regmap_readable(struct regmap *map, unsigned int reg);
bool regmap_volatile(struct regmap *map, unsigned int reg);
bool regmap_precious(struct regmap *map, unsigned int reg);
bool regmap_writeable_noinc(struct regmap *map, unsigned int reg);
bool regmap_readable_noinc(struct regmap *map, unsigned int reg);
int _regmap_write(struct regmap *map, unsigned int reg,
unsigned int val);
struct regmap_range_node {
struct rb_node node;
const char *name;
struct regmap *map;
unsigned int range_min;
unsigned int range_max;
unsigned int selector_reg;
unsigned int selector_mask;
int selector_shift;
unsigned int window_start;
unsigned int window_len;
};
struct regmap_field {
struct regmap *regmap;
unsigned int mask;
/* lsb */
unsigned int shift;
unsigned int reg;
unsigned int id_size;
unsigned int id_offset;
};
#ifdef CONFIG_DEBUG_FS
extern void regmap_debugfs_initcall(void);
regmap: debugfs: Fix handling of name string for debugfs init delays In regmap_debugfs_init the initialisation of the debugfs is delayed if the root node isn't ready yet. Most callers of regmap_debugfs_init pass the name from the regmap_config, which is considered temporary ie. may be unallocated after the regmap_init call returns. This leads to a potential use after free, where config->name has been freed by the time it is used in regmap_debugfs_initcall. This situation can be seen on Zynq, where the architecture init_irq callback registers a syscon device, using a local variable for the regmap_config. As init_irq is very early in the platform bring up the regmap debugfs root isn't ready yet. Although this doesn't crash it does result in the debugfs entry not having the correct name. Regmap already sets map->name from config->name on the regmap_init path and the fact that a separate field is used to pass the name to regmap_debugfs_init appears to be an artifact of the debugfs name being added before the map name. As such this patch updates regmap_debugfs_init to use map->name, which is already duplicated from the config avoiding the issue. This does however leave two lose ends, both regmap_attach_dev and regmap_reinit_cache can be called after a regmap is registered and would have had the effect of applying a new name to the debugfs entries. In both of these cases it was chosen to update the map name. In the case of regmap_attach_dev there are 3 users that currently use this function to update the name, thus doing so avoids changes for those users and it seems reasonable that attaching a device would want to set the name of the map. In the case of regmap_reinit_cache the primary use-case appears to be devices that need some register access to identify the device (for example devices in the same family) and then update the cache to match the exact hardware. Whilst no users do currently update the name here, given the use-case it seemed reasonable the name might want to be updated once the device is better identified. Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com> Link: https://lore.kernel.org/r/20200917120828.12987-1-ckeepax@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
2020-09-17 12:08:28 +00:00
extern void regmap_debugfs_init(struct regmap *map);
extern void regmap_debugfs_exit(struct regmap *map);
static inline void regmap_debugfs_disable(struct regmap *map)
{
map->debugfs_disable = true;
}
#else
static inline void regmap_debugfs_initcall(void) { }
regmap: debugfs: Fix handling of name string for debugfs init delays In regmap_debugfs_init the initialisation of the debugfs is delayed if the root node isn't ready yet. Most callers of regmap_debugfs_init pass the name from the regmap_config, which is considered temporary ie. may be unallocated after the regmap_init call returns. This leads to a potential use after free, where config->name has been freed by the time it is used in regmap_debugfs_initcall. This situation can be seen on Zynq, where the architecture init_irq callback registers a syscon device, using a local variable for the regmap_config. As init_irq is very early in the platform bring up the regmap debugfs root isn't ready yet. Although this doesn't crash it does result in the debugfs entry not having the correct name. Regmap already sets map->name from config->name on the regmap_init path and the fact that a separate field is used to pass the name to regmap_debugfs_init appears to be an artifact of the debugfs name being added before the map name. As such this patch updates regmap_debugfs_init to use map->name, which is already duplicated from the config avoiding the issue. This does however leave two lose ends, both regmap_attach_dev and regmap_reinit_cache can be called after a regmap is registered and would have had the effect of applying a new name to the debugfs entries. In both of these cases it was chosen to update the map name. In the case of regmap_attach_dev there are 3 users that currently use this function to update the name, thus doing so avoids changes for those users and it seems reasonable that attaching a device would want to set the name of the map. In the case of regmap_reinit_cache the primary use-case appears to be devices that need some register access to identify the device (for example devices in the same family) and then update the cache to match the exact hardware. Whilst no users do currently update the name here, given the use-case it seemed reasonable the name might want to be updated once the device is better identified. Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com> Link: https://lore.kernel.org/r/20200917120828.12987-1-ckeepax@opensource.cirrus.com Signed-off-by: Mark Brown <broonie@kernel.org>
2020-09-17 12:08:28 +00:00
static inline void regmap_debugfs_init(struct regmap *map) { }
static inline void regmap_debugfs_exit(struct regmap *map) { }
static inline void regmap_debugfs_disable(struct regmap *map) { }
#endif
/* regcache core declarations */
int regcache_init(struct regmap *map, const struct regmap_config *config);
void regcache_exit(struct regmap *map);
int regcache_read(struct regmap *map,
unsigned int reg, unsigned int *value);
int regcache_write(struct regmap *map,
unsigned int reg, unsigned int value);
int regcache_sync(struct regmap *map);
int regcache_sync_block(struct regmap *map, void *block,
unsigned long *cache_present,
unsigned int block_base, unsigned int start,
unsigned int end);
static inline const void *regcache_get_val_addr(struct regmap *map,
const void *base,
unsigned int idx)
{
return base + (map->cache_word_size * idx);
}
unsigned int regcache_get_val(struct regmap *map, const void *base,
unsigned int idx);
bool regcache_set_val(struct regmap *map, void *base, unsigned int idx,
unsigned int val);
int regcache_lookup_reg(struct regmap *map, unsigned int reg);
int _regmap_raw_write(struct regmap *map, unsigned int reg,
const void *val, size_t val_len, bool noinc);
void regmap_async_complete_cb(struct regmap_async *async, int ret);
enum regmap_endian regmap_get_val_endian(struct device *dev,
const struct regmap_bus *bus,
const struct regmap_config *config);
extern struct regcache_ops regcache_rbtree_ops;
extern struct regcache_ops regcache_lzo_ops;
extern struct regcache_ops regcache_flat_ops;
regmap: introduce regmap_name to fix syscon regmap trace events This patch fixes a NULL pointer dereference when enabling regmap event tracing in the presence of a syscon regmap, introduced by commit bdb0066df96e ("mfd: syscon: Decouple syscon interface from platform devices"). That patch introduced syscon regmaps that have their dev field set to NULL. The regmap trace events expect it to point to a valid struct device and feed it to dev_name(): $ echo 1 > /sys/kernel/debug/tracing/events/regmap/enable Unable to handle kernel NULL pointer dereference at virtual address 0000002c pgd = 80004000 [0000002c] *pgd=00000000 Internal error: Oops: 17 [#1] SMP ARM Modules linked in: coda videobuf2_vmalloc CPU: 0 PID: 304 Comm: kworker/0:2 Not tainted 4.0.0-rc2+ #9197 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Workqueue: events_freezable thermal_zone_device_check task: 9f25a200 ti: 9f1ee000 task.ti: 9f1ee000 PC is at ftrace_raw_event_regmap_block+0x3c/0xe4 LR is at _regmap_raw_read+0x1bc/0x1cc pc : [<803636e8>] lr : [<80365f2c>] psr: 600f0093 sp : 9f1efd78 ip : 9f1efdb8 fp : 9f1efdb4 r10: 00000004 r9 : 00000001 r8 : 00000001 r7 : 00000180 r6 : 00000000 r5 : 9f00e3c0 r4 : 00000003 r3 : 00000001 r2 : 00000180 r1 : 00000000 r0 : 9f00e3c0 Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c5387d Table: 2d91004a DAC: 00000015 Process kworker/0:2 (pid: 304, stack limit = 0x9f1ee210) Stack: (0x9f1efd78 to 0x9f1f0000) fd60: 9f1efda4 9f1efd88 fd80: 800708c0 805f9510 80927140 800f0013 9f1fc800 9eb2f490 00000000 00000180 fda0: 808e3840 00000001 9f1efdfc 9f1efdb8 80365f2c 803636b8 805f8958 800708e0 fdc0: a00f0013 803636ac 9f16de00 00000180 80927140 9f1fc800 9f1fc800 9f1efe6c fde0: 9f1efe6c 9f732400 00000000 00000000 9f1efe1c 9f1efe00 80365f70 80365d7c fe00: 80365f3c 9f1fc800 9f1fc800 00000180 9f1efe44 9f1efe20 803656a4 80365f48 fe20: 9f1fc800 00000180 9f1efe6c 9f1efe6c 9f732400 00000000 9f1efe64 9f1efe48 fe40: 803657bc 80365634 00000001 9e95f910 9f1fc800 9f1efeb4 9f1efe8c 9f1efe68 fe60: 80452ac0 80365778 9f1efe8c 9f1efe78 9e93d400 9e93d5e8 9f1efeb4 9f72ef40 fe80: 9f1efeac 9f1efe90 8044e11c 80452998 8045298c 9e93d608 9e93d400 808e1978 fea0: 9f1efecc 9f1efeb0 8044fd14 8044e0d0 ffffffff 9f25a200 9e93d608 9e481380 fec0: 9f1efedc 9f1efed0 8044fde8 8044fcec 9f1eff1c 9f1efee0 80038d50 8044fdd8 fee0: 9f1ee020 9f72ef40 9e481398 00000000 00000008 9f72ef54 9f1ee020 9f72ef40 ff00: 9e481398 9e481380 00000008 9f72ef40 9f1eff5c 9f1eff20 80039754 80038bfc ff20: 00000000 9e481380 80894100 808e1662 00000000 9e4f2ec0 00000000 9e481380 ff40: 800396f8 00000000 00000000 00000000 9f1effac 9f1eff60 8003e020 80039704 ff60: ffffffff 00000000 ffffffff 9e481380 00000000 00000000 9f1eff78 9f1eff78 ff80: 00000000 00000000 9f1eff88 9f1eff88 9e4f2ec0 8003df30 00000000 00000000 ffa0: 00000000 9f1effb0 8000eb60 8003df3c 00000000 00000000 00000000 00000000 ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 ffe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff Backtrace: [<803636ac>] (ftrace_raw_event_regmap_block) from [<80365f2c>] (_regmap_raw_read+0x1bc/0x1cc) r9:00000001 r8:808e3840 r7:00000180 r6:00000000 r5:9eb2f490 r4:9f1fc800 [<80365d70>] (_regmap_raw_read) from [<80365f70>] (_regmap_bus_read+0x34/0x6c) r10:00000000 r9:00000000 r8:9f732400 r7:9f1efe6c r6:9f1efe6c r5:9f1fc800 r4:9f1fc800 [<80365f3c>] (_regmap_bus_read) from [<803656a4>] (_regmap_read+0x7c/0x144) r6:00000180 r5:9f1fc800 r4:9f1fc800 r3:80365f3c [<80365628>] (_regmap_read) from [<803657bc>] (regmap_read+0x50/0x70) r9:00000000 r8:9f732400 r7:9f1efe6c r6:9f1efe6c r5:00000180 r4:9f1fc800 [<8036576c>] (regmap_read) from [<80452ac0>] (imx_get_temp+0x134/0x1a4) r6:9f1efeb4 r5:9f1fc800 r4:9e95f910 r3:00000001 [<8045298c>] (imx_get_temp) from [<8044e11c>] (thermal_zone_get_temp+0x58/0x74) r7:9f72ef40 r6:9f1efeb4 r5:9e93d5e8 r4:9e93d400 [<8044e0c4>] (thermal_zone_get_temp) from [<8044fd14>] (thermal_zone_device_update+0x34/0xec) r6:808e1978 r5:9e93d400 r4:9e93d608 r3:8045298c [<8044fce0>] (thermal_zone_device_update) from [<8044fde8>] (thermal_zone_device_check+0x1c/0x20) r5:9e481380 r4:9e93d608 [<8044fdcc>] (thermal_zone_device_check) from [<80038d50>] (process_one_work+0x160/0x3d4) [<80038bf0>] (process_one_work) from [<80039754>] (worker_thread+0x5c/0x4f4) r10:9f72ef40 r9:00000008 r8:9e481380 r7:9e481398 r6:9f72ef40 r5:9f1ee020 r4:9f72ef54 [<800396f8>] (worker_thread) from [<8003e020>] (kthread+0xf0/0x108) r10:00000000 r9:00000000 r8:00000000 r7:800396f8 r6:9e481380 r5:00000000 r4:9e4f2ec0 [<8003df30>] (kthread) from [<8000eb60>] (ret_from_fork+0x14/0x34) r7:00000000 r6:00000000 r5:8003df30 r4:9e4f2ec0 Code: e3140040 1a00001a e3140020 1a000016 (e596002c) ---[ end trace 193c15c2494ec960 ]--- Fixes: bdb0066df96e (mfd: syscon: Decouple syscon interface from platform devices) Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Mark Brown <broonie@kernel.org> Cc: stable@vger.kernel.org
2015-03-09 11:20:13 +00:00
static inline const char *regmap_name(const struct regmap *map)
{
if (map->dev)
return dev_name(map->dev);
return map->name;
}
static inline unsigned int regmap_get_offset(const struct regmap *map,
unsigned int index)
{
if (map->reg_stride_order >= 0)
return index << map->reg_stride_order;
else
return index * map->reg_stride;
}
static inline unsigned int regcache_get_index_by_order(const struct regmap *map,
unsigned int reg)
{
return reg >> map->reg_stride_order;
}
#endif