diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt index 8b92d4576c42..25d9e9c2fd53 100644 --- a/Documentation/devicetree/bindings/mfd/syscon.txt +++ b/Documentation/devicetree/bindings/mfd/syscon.txt @@ -16,9 +16,17 @@ Required properties: Optional property: - reg-io-width: the size (in bytes) of the IO accesses that should be performed on the device. +- hwlocks: reference to a phandle of a hardware spinlock provider node. Examples: gpr: iomuxc-gpr@20e0000 { compatible = "fsl,imx6q-iomuxc-gpr", "syscon"; reg = <0x020e0000 0x38>; + hwlocks = <&hwlock1 1>; +}; + +hwlock1: hwspinlock@40500000 { + ... + reg = <0x40500000 0x1000>; + #hwlock-cells = <1>; }; diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig index 3a1535d812d8..0368fd7b3a41 100644 --- a/drivers/base/regmap/Kconfig +++ b/drivers/base/regmap/Kconfig @@ -6,7 +6,6 @@ config REGMAP default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_W1 || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ) select IRQ_DOMAIN if REGMAP_IRQ - select REGMAP_HWSPINLOCK if HWSPINLOCK=y bool config REGCACHE_COMPRESSED @@ -38,6 +37,3 @@ config REGMAP_MMIO config REGMAP_IRQ bool - -config REGMAP_HWSPINLOCK - bool diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h index 8641183cac2f..53785e0e297a 100644 --- a/drivers/base/regmap/internal.h +++ b/drivers/base/regmap/internal.h @@ -77,6 +77,7 @@ struct regmap { int async_ret; #ifdef CONFIG_DEBUG_FS + bool debugfs_disable; struct dentry *debugfs; const char *debugfs_name; @@ -215,10 +216,17 @@ struct regmap_field { extern void regmap_debugfs_initcall(void); extern void regmap_debugfs_init(struct regmap *map, const char *name); 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, const char *name) { } static inline void regmap_debugfs_exit(struct regmap *map) { } +static inline void regmap_debugfs_disable(struct regmap *map) { } #endif /* regcache core declarations */ diff --git a/drivers/base/regmap/regcache-flat.c b/drivers/base/regmap/regcache-flat.c index 4d2e50bfc726..bc6cd88b8cc6 100644 --- a/drivers/base/regmap/regcache-flat.c +++ b/drivers/base/regmap/regcache-flat.c @@ -37,9 +37,12 @@ static int regcache_flat_init(struct regmap *map) cache = map->cache; - for (i = 0; i < map->num_reg_defaults; i++) - cache[regcache_flat_get_index(map, map->reg_defaults[i].reg)] = - map->reg_defaults[i].def; + for (i = 0; i < map->num_reg_defaults; i++) { + unsigned int reg = map->reg_defaults[i].reg; + unsigned int index = regcache_flat_get_index(map, reg); + + cache[index] = map->reg_defaults[i].def; + } return 0; } @@ -56,8 +59,9 @@ static int regcache_flat_read(struct regmap *map, unsigned int reg, unsigned int *value) { unsigned int *cache = map->cache; + unsigned int index = regcache_flat_get_index(map, reg); - *value = cache[regcache_flat_get_index(map, reg)]; + *value = cache[index]; return 0; } @@ -66,8 +70,9 @@ static int regcache_flat_write(struct regmap *map, unsigned int reg, unsigned int value) { unsigned int *cache = map->cache; + unsigned int index = regcache_flat_get_index(map, reg); - cache[regcache_flat_get_index(map, reg)] = value; + cache[index] = value; return 0; } diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index 36ce3511c733..f3266334063e 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -529,6 +529,18 @@ void regmap_debugfs_init(struct regmap *map, const char *name) struct regmap_range_node *range_node; const char *devname = "dummy"; + /* + * Userspace can initiate reads from the hardware over debugfs. + * Normally internal regmap structures and buffers are protected with + * a mutex or a spinlock, but if the regmap owner decided to disable + * all locking mechanisms, this is no longer the case. For safety: + * don't create the debugfs entries if locking is disabled. + */ + if (map->debugfs_disable) { + dev_dbg(map->dev, "regmap locking disabled - not creating debugfs entries\n"); + return; + } + /* If we don't have the debugfs root yet, postpone init */ if (!regmap_debugfs_root) { struct regmap_debugfs_node *node; diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 9fb3a792642b..be55e5a0e38c 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -414,7 +414,6 @@ static unsigned int regmap_parse_64_native(const void *buf) } #endif -#ifdef REGMAP_HWSPINLOCK static void regmap_lock_hwlock(void *__map) { struct regmap *map = __map; @@ -457,7 +456,11 @@ static void regmap_unlock_hwlock_irqrestore(void *__map) hwspin_unlock_irqrestore(map->hwlock, &map->spinlock_flags); } -#endif + +static void regmap_lock_unlock_none(void *__map) +{ + +} static void regmap_lock_mutex(void *__map) { @@ -669,16 +672,26 @@ struct regmap *__regmap_init(struct device *dev, goto err; } - if (config->lock && config->unlock) { + if (config->name) { + map->name = kstrdup_const(config->name, GFP_KERNEL); + if (!map->name) { + ret = -ENOMEM; + goto err_map; + } + } + + if (config->disable_locking) { + map->lock = map->unlock = regmap_lock_unlock_none; + regmap_debugfs_disable(map); + } else if (config->lock && config->unlock) { map->lock = config->lock; map->unlock = config->unlock; map->lock_arg = config->lock_arg; - } else if (config->hwlock_id) { -#ifdef REGMAP_HWSPINLOCK + } else if (config->use_hwlock) { map->hwlock = hwspin_lock_request_specific(config->hwlock_id); if (!map->hwlock) { ret = -ENXIO; - goto err_map; + goto err_name; } switch (config->hwlock_mode) { @@ -697,10 +710,6 @@ struct regmap *__regmap_init(struct device *dev, } map->lock_arg = map; -#else - ret = -EINVAL; - goto err_map; -#endif } else { if ((bus && bus->fast_io) || config->fast_io) { @@ -762,7 +771,6 @@ struct regmap *__regmap_init(struct device *dev, map->volatile_reg = config->volatile_reg; map->precious_reg = config->precious_reg; map->cache_type = config->cache_type; - map->name = config->name; spin_lock_init(&map->async_lock); INIT_LIST_HEAD(&map->async_list); @@ -1116,8 +1124,10 @@ err_range: regmap_range_exit(map); kfree(map->work_buf); err_hwlock: - if (IS_ENABLED(REGMAP_HWSPINLOCK) && map->hwlock) + if (map->hwlock) hwspin_lock_free(map->hwlock); +err_name: + kfree_const(map->name); err_map: kfree(map); err: @@ -1305,8 +1315,9 @@ void regmap_exit(struct regmap *map) kfree(async->work_buf); kfree(async); } - if (IS_ENABLED(REGMAP_HWSPINLOCK) && map->hwlock) + if (map->hwlock) hwspin_lock_free(map->hwlock); + kfree_const(map->name); kfree(map); } EXPORT_SYMBOL_GPL(regmap_exit); diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index b93fe4c4957a..7eaa40bc703f 100644 --- a/drivers/mfd/syscon.c +++ b/drivers/mfd/syscon.c @@ -13,6 +13,7 @@ */ #include +#include #include #include #include @@ -87,6 +88,24 @@ static struct syscon *of_syscon_register(struct device_node *np) if (ret) reg_io_width = 4; + ret = of_hwspin_lock_get_id(np, 0); + if (ret > 0 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) { + syscon_config.use_hwlock = true; + syscon_config.hwlock_id = ret; + syscon_config.hwlock_mode = HWLOCK_IRQSTATE; + } else if (ret < 0) { + switch (ret) { + case -ENOENT: + /* Ignore missing hwlock, it's optional. */ + break; + default: + pr_err("Failed to retrieve valid hwlock: %d\n", ret); + /* fall-through */ + case -EPROBE_DEFER: + goto err_regmap; + } + } + syscon_config.reg_stride = reg_io_width; syscon_config.val_bits = reg_io_width * 8; syscon_config.max_register = resource_size(&res) - reg_io_width; diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 15eddc1353ba..671515911b03 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -264,6 +264,9 @@ typedef void (*regmap_unlock)(void *); * field is NULL but precious_table (see below) is not, the * check is performed on such table (a register is precious if * it belongs to one of the ranges specified by precious_table). + * @disable_locking: This regmap is either protected by external means or + * is guaranteed not be be accessed from multiple threads. + * Don't use any locking mechanisms. * @lock: Optional lock callback (overrides regmap's default lock * function, based on spinlock or mutex). * @unlock: As above for unlocking. @@ -317,6 +320,7 @@ typedef void (*regmap_unlock)(void *); * * @ranges: Array of configuration entries for virtual address ranges. * @num_ranges: Number of range configuration entries. + * @use_hwlock: Indicate if a hardware spinlock should be used. * @hwlock_id: Specify the hardware spinlock id. * @hwlock_mode: The hardware spinlock mode, should be HWLOCK_IRQSTATE, * HWLOCK_IRQ or 0. @@ -333,6 +337,8 @@ struct regmap_config { 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 disable_locking; regmap_lock lock; regmap_unlock unlock; void *lock_arg; @@ -365,6 +371,7 @@ struct regmap_config { const struct regmap_range_cfg *ranges; unsigned int num_ranges; + bool use_hwlock; unsigned int hwlock_id; unsigned int hwlock_mode; };