From af1a71eda7ad9bacd5a5c577b6b89a70c4b1a53a Mon Sep 17 00:00:00 2001 From: Romuald Jeanne Date: Tue, 25 Jul 2023 10:41:17 +0200 Subject: [PATCH 08/22] v5.15-stm32mp-r2.1 HWSPINLOCK Signed-off-by: Romuald Jeanne --- Documentation/locking/hwspinlock.rst | 10 ++- drivers/hwspinlock/hwspinlock_core.c | 80 +++++++++++++++++++----- drivers/hwspinlock/hwspinlock_internal.h | 2 + drivers/hwspinlock/stm32_hwspinlock.c | 58 ++++++++++------- 4 files changed, 109 insertions(+), 41 deletions(-) diff --git a/Documentation/locking/hwspinlock.rst b/Documentation/locking/hwspinlock.rst index 6f03713b7003..605bd2dc8a03 100644 --- a/Documentation/locking/hwspinlock.rst +++ b/Documentation/locking/hwspinlock.rst @@ -54,9 +54,11 @@ Should be called from a process context (might sleep). struct hwspinlock *hwspin_lock_request_specific(unsigned int id); Assign a specific hwspinlock id and return its address, or NULL -if that hwspinlock is already in use. Usually board code will -be calling this function in order to reserve specific hwspinlock -ids for predefined purposes. +if that hwspinlock is already in use and not shared. If that specific +hwspinlock is declared as shared, it can be requested and used by +several users. +Usually board code will be calling this function in order to reserve +specific hwspinlock ids for predefined purposes. Should be called from a process context (might sleep). @@ -449,11 +451,13 @@ of which represents a single hardware lock:: * struct hwspinlock - this struct represents a single hwspinlock instance * @bank: the hwspinlock_device structure which owns this lock * @lock: initialized and used by hwspinlock core + * @refcount: number of users (when shared) * @priv: private data, owned by the underlying platform-specific hwspinlock drv */ struct hwspinlock { struct hwspinlock_device *bank; spinlock_t lock; + unsigned int refcount; void *priv; }; diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index fd5f5c5a5244..a2197af8973d 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -29,6 +29,8 @@ /* radix tree tags */ #define HWSPINLOCK_UNUSED (0) /* tags an hwspinlock as unused */ +#define HWSPINLOCK_EXCLUSIVE (1) /* tags an hwspinlock as exclusive */ +#define HWSPINLOCK_SHARED (2) /* tags an hwspinlock as shared */ /* * A radix tree is used to maintain the available hwspinlock instances. @@ -308,7 +310,7 @@ EXPORT_SYMBOL_GPL(__hwspin_unlock); * @hwlock_spec: hwlock specifier as found in the device tree * * This is a simple translation function, suitable for hwspinlock platform - * drivers that only has a lock specifier length of 1. + * drivers that only has a lock specifier length of 1 or 2. * * Returns a relative index of the lock within a specified bank on success, * or -EINVAL on invalid specifier cell count. @@ -316,7 +318,8 @@ EXPORT_SYMBOL_GPL(__hwspin_unlock); static inline int of_hwspin_lock_simple_xlate(const struct of_phandle_args *hwlock_spec) { - if (WARN_ON(hwlock_spec->args_count != 1)) + if (WARN_ON(hwlock_spec->args_count != 1 && + hwlock_spec->args_count != 2)) return -EINVAL; return hwlock_spec->args[0]; @@ -339,11 +342,12 @@ of_hwspin_lock_simple_xlate(const struct of_phandle_args *hwlock_spec) int of_hwspin_lock_get_id(struct device_node *np, int index) { struct of_phandle_args args; - struct hwspinlock *hwlock; + struct hwspinlock *hwlock, *tmp; struct radix_tree_iter iter; void **slot; int id; int ret; + unsigned int tag; ret = of_parse_phandle_with_args(np, "hwlocks", "#hwlock-cells", index, &args); @@ -383,6 +387,37 @@ int of_hwspin_lock_get_id(struct device_node *np, int index) } id += hwlock->bank->base_id; + /* Set the EXCLUSIVE / SHARED tag */ + if (args.args_count == 2 && args.args[1]) { + /* Tag SHARED unless already tagged EXCLUSIVE */ + if (radix_tree_tag_get(&hwspinlock_tree, id, + HWSPINLOCK_EXCLUSIVE)) { + ret = -EINVAL; + goto out; + } + tag = HWSPINLOCK_SHARED; + } else { + /* Tag EXCLUSIVE unless already tagged SHARED */ + if (radix_tree_tag_get(&hwspinlock_tree, id, + HWSPINLOCK_SHARED)) { + ret = -EINVAL; + goto out; + } + tag = HWSPINLOCK_EXCLUSIVE; + } + + /* mark this hwspinlock */ + hwlock = radix_tree_lookup(&hwspinlock_tree, id); + if (!hwlock) { + ret = -EINVAL; + goto out; + } + + tmp = radix_tree_tag_set(&hwspinlock_tree, id, tag); + + /* self-sanity check which should never fail */ + WARN_ON(tmp != hwlock); + out: of_node_put(args.np); return ret ? ret : id; @@ -505,6 +540,7 @@ int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, spin_lock_init(&hwlock->lock); hwlock->bank = bank; + hwlock->refcount = 0; ret = hwspin_lock_register_single(hwlock, base_id + i); if (ret) @@ -647,7 +683,7 @@ static int __hwspin_lock_request(struct hwspinlock *hwlock) { struct device *dev = hwlock->bank->dev; struct hwspinlock *tmp; - int ret; + int ret, id; /* prevent underlying implementation from being removed */ if (!try_module_get(dev->driver->owner)) { @@ -666,13 +702,18 @@ static int __hwspin_lock_request(struct hwspinlock *hwlock) ret = 0; + /* update shareable refcount */ + id = hwlock_to_id(hwlock); + if (radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_SHARED) && + hwlock->refcount++) + goto out; + /* mark hwspinlock as used, should not fail */ - tmp = radix_tree_tag_clear(&hwspinlock_tree, hwlock_to_id(hwlock), - HWSPINLOCK_UNUSED); + tmp = radix_tree_tag_clear(&hwspinlock_tree, id, HWSPINLOCK_UNUSED); /* self-sanity check that should never fail */ WARN_ON(tmp != hwlock); - +out: return ret; } @@ -766,9 +807,9 @@ struct hwspinlock *hwspin_lock_request_specific(unsigned int id) /* sanity check (this shouldn't happen) */ WARN_ON(hwlock_to_id(hwlock) != id); - /* make sure this hwspinlock is unused */ - ret = radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED); - if (ret == 0) { + /* make sure this hwspinlock is unused or shareable */ + if (!radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_SHARED) && + !radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED)) { pr_warn("hwspinlock %u is already in use\n", id); hwlock = NULL; goto out; @@ -801,7 +842,7 @@ int hwspin_lock_free(struct hwspinlock *hwlock) { struct device *dev; struct hwspinlock *tmp; - int ret; + int ret, id; if (!hwlock) { pr_err("invalid hwlock\n"); @@ -812,28 +853,33 @@ int hwspin_lock_free(struct hwspinlock *hwlock) mutex_lock(&hwspinlock_tree_lock); /* make sure the hwspinlock is used */ - ret = radix_tree_tag_get(&hwspinlock_tree, hwlock_to_id(hwlock), - HWSPINLOCK_UNUSED); + id = hwlock_to_id(hwlock); + ret = radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED); if (ret == 1) { dev_err(dev, "%s: hwlock is already free\n", __func__); dump_stack(); ret = -EINVAL; - goto out; + goto unlock; } /* notify the underlying device that power is not needed */ pm_runtime_put(dev); + /* update shareable refcount */ + if (radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_SHARED) && + --hwlock->refcount) + goto put; + /* mark this hwspinlock as available */ - tmp = radix_tree_tag_set(&hwspinlock_tree, hwlock_to_id(hwlock), - HWSPINLOCK_UNUSED); + tmp = radix_tree_tag_set(&hwspinlock_tree, id, HWSPINLOCK_UNUSED); /* sanity check (this shouldn't happen) */ WARN_ON(tmp != hwlock); +put: module_put(dev->driver->owner); -out: +unlock: mutex_unlock(&hwspinlock_tree_lock); return ret; } diff --git a/drivers/hwspinlock/hwspinlock_internal.h b/drivers/hwspinlock/hwspinlock_internal.h index 29892767bb7a..e1f9c9600635 100644 --- a/drivers/hwspinlock/hwspinlock_internal.h +++ b/drivers/hwspinlock/hwspinlock_internal.h @@ -35,11 +35,13 @@ struct hwspinlock_ops { * struct hwspinlock - this struct represents a single hwspinlock instance * @bank: the hwspinlock_device structure which owns this lock * @lock: initialized and used by hwspinlock core + * @refcount: number of users (when shared) * @priv: private data, owned by the underlying platform-specific hwspinlock drv */ struct hwspinlock { struct hwspinlock_device *bank; spinlock_t lock; + unsigned int refcount; void *priv; }; diff --git a/drivers/hwspinlock/stm32_hwspinlock.c b/drivers/hwspinlock/stm32_hwspinlock.c index 3ad0ce0da4d9..5bd11a7fab65 100644 --- a/drivers/hwspinlock/stm32_hwspinlock.c +++ b/drivers/hwspinlock/stm32_hwspinlock.c @@ -54,8 +54,23 @@ static const struct hwspinlock_ops stm32_hwspinlock_ops = { .relax = stm32_hwspinlock_relax, }; +static void stm32_hwspinlock_disable_clk(void *data) +{ + struct platform_device *pdev = data; + struct stm32_hwspinlock *hw = platform_get_drvdata(pdev); + struct device *dev = &pdev->dev; + + pm_runtime_get_sync(dev); + pm_runtime_disable(dev); + pm_runtime_set_suspended(dev); + pm_runtime_put_noidle(dev); + + clk_disable_unprepare(hw->clk); +} + static int stm32_hwspinlock_probe(struct platform_device *pdev) { + struct device *dev = &pdev->dev; struct stm32_hwspinlock *hw; void __iomem *io_base; size_t array_size; @@ -66,41 +81,43 @@ static int stm32_hwspinlock_probe(struct platform_device *pdev) return PTR_ERR(io_base); array_size = STM32_MUTEX_NUM_LOCKS * sizeof(struct hwspinlock); - hw = devm_kzalloc(&pdev->dev, sizeof(*hw) + array_size, GFP_KERNEL); + hw = devm_kzalloc(dev, sizeof(*hw) + array_size, GFP_KERNEL); if (!hw) return -ENOMEM; - hw->clk = devm_clk_get(&pdev->dev, "hsem"); + hw->clk = devm_clk_get(dev, "hsem"); if (IS_ERR(hw->clk)) return PTR_ERR(hw->clk); - for (i = 0; i < STM32_MUTEX_NUM_LOCKS; i++) - hw->bank.lock[i].priv = io_base + i * sizeof(u32); + ret = clk_prepare_enable(hw->clk); + if (ret) { + dev_err(dev, "Failed to prepare_enable clock\n"); + return ret; + } platform_set_drvdata(pdev, hw); - pm_runtime_enable(&pdev->dev); - ret = hwspin_lock_register(&hw->bank, &pdev->dev, &stm32_hwspinlock_ops, - 0, STM32_MUTEX_NUM_LOCKS); + pm_runtime_get_noresume(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + pm_runtime_put(dev); - if (ret) - pm_runtime_disable(&pdev->dev); + ret = devm_add_action_or_reset(dev, stm32_hwspinlock_disable_clk, pdev); + if (ret) { + dev_err(dev, "Failed to register action\n"); + return ret; + } - return ret; -} + for (i = 0; i < STM32_MUTEX_NUM_LOCKS; i++) + hw->bank.lock[i].priv = io_base + i * sizeof(u32); -static int stm32_hwspinlock_remove(struct platform_device *pdev) -{ - struct stm32_hwspinlock *hw = platform_get_drvdata(pdev); - int ret; + ret = devm_hwspin_lock_register(dev, &hw->bank, &stm32_hwspinlock_ops, + 0, STM32_MUTEX_NUM_LOCKS); - ret = hwspin_lock_unregister(&hw->bank); if (ret) - dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret); - - pm_runtime_disable(&pdev->dev); + dev_err(dev, "Failed to register hwspinlock\n"); - return 0; + return ret; } static int __maybe_unused stm32_hwspinlock_runtime_suspend(struct device *dev) @@ -135,7 +152,6 @@ MODULE_DEVICE_TABLE(of, stm32_hwpinlock_ids); static struct platform_driver stm32_hwspinlock_driver = { .probe = stm32_hwspinlock_probe, - .remove = stm32_hwspinlock_remove, .driver = { .name = "stm32_hwspinlock", .of_match_table = stm32_hwpinlock_ids, -- 2.17.1