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meta-st-stm32mp/recipes-kernel/linux/linux-stm32mp/5.15/5.15.118/0008-v5.15-stm32mp-r2.1-HWS...

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From af1a71eda7ad9bacd5a5c577b6b89a70c4b1a53a Mon Sep 17 00:00:00 2001
From: Romuald Jeanne <romuald.jeanne@st.com>
Date: Tue, 25 Jul 2023 10:41:17 +0200
Subject: [PATCH 08/22] v5.15-stm32mp-r2.1 HWSPINLOCK
Signed-off-by: Romuald Jeanne <romuald.jeanne@st.com>
---
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
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