linux-stable/drivers/base/regmap/internal.h
Vladimir Oltean 67021f25d9
regmap: teach regmap to use raw spinlocks if requested in the config
Some drivers might access regmap in a context where a raw spinlock is
held. An example is drivers/irqchip/irq-ls-extirq.c, which calls
regmap_update_bits() from struct irq_chip :: irq_set_type, which is a
method called by __irq_set_trigger() under the desc->lock raw spin lock.

Since desc->lock is a raw spin lock and the regmap internal lock for
mmio is a plain spinlock (which can become sleepable on RT), this is an
invalid locking scheme and we get a splat stating that this is a
"[ BUG: Invalid wait context ]".

It seems reasonable for regmap to have an option use a raw spinlock too,
so add that in the config such that drivers can request it.

Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20210825205041.927788-2-vladimir.oltean@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-08-26 12:07:32 +01:00

304 lines
8.3 KiB
C

/* 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);
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) { }
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;
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