Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig
index e895d29..37740e9 100644
--- a/drivers/hwspinlock/Kconfig
+++ b/drivers/hwspinlock/Kconfig
@@ -9,7 +9,7 @@
 config HWSPINLOCK_OMAP
 	tristate "OMAP Hardware Spinlock device"
 	depends on HWSPINLOCK
-	depends on ARCH_OMAP4 || SOC_OMAP5 || SOC_DRA7XX || SOC_AM33XX || SOC_AM43XX
+	depends on ARCH_OMAP4 || SOC_OMAP5 || SOC_DRA7XX || SOC_AM33XX || SOC_AM43XX || ARCH_K3
 	help
 	  Say y here to support the OMAP Hardware Spinlock device (firstly
 	  introduced in OMAP4).
@@ -49,6 +49,15 @@
 
 	  If unsure, say N.
 
+config HWSPINLOCK_STM32
+	tristate "STM32 Hardware Spinlock device"
+	depends on MACH_STM32MP157
+	depends on HWSPINLOCK
+	help
+	  Say y here to support the STM32 Hardware Spinlock device.
+
+	  If unsure, say N.
+
 config HSEM_U8500
 	tristate "STE Hardware Semaphore functionality"
 	depends on HWSPINLOCK
diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile
index b87c01a..ed053e3 100644
--- a/drivers/hwspinlock/Makefile
+++ b/drivers/hwspinlock/Makefile
@@ -8,4 +8,5 @@
 obj-$(CONFIG_HWSPINLOCK_QCOM)		+= qcom_hwspinlock.o
 obj-$(CONFIG_HWSPINLOCK_SIRF)		+= sirf_hwspinlock.o
 obj-$(CONFIG_HWSPINLOCK_SPRD)		+= sprd_hwspinlock.o
+obj-$(CONFIG_HWSPINLOCK_STM32)		+= stm32_hwspinlock.o
 obj-$(CONFIG_HSEM_U8500)		+= u8500_hsem.o
diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c
index 2bad40d..8862445 100644
--- a/drivers/hwspinlock/hwspinlock_core.c
+++ b/drivers/hwspinlock/hwspinlock_core.c
@@ -9,6 +9,7 @@
 
 #define pr_fmt(fmt)    "%s: " fmt, __func__
 
+#include <linux/delay.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/spinlock.h>
@@ -23,6 +24,9 @@
 
 #include "hwspinlock_internal.h"
 
+/* retry delay used in atomic context */
+#define HWSPINLOCK_RETRY_DELAY_US	100
+
 /* radix tree tags */
 #define HWSPINLOCK_UNUSED	(0) /* tags an hwspinlock as unused */
 
@@ -68,11 +72,11 @@
  * user need some time-consuming or sleepable operations under the hardware
  * lock, they need one sleepable lock (like mutex) to protect the operations.
  *
- * If the mode is not HWLOCK_RAW, upon a successful return from this function,
- * preemption (and possibly interrupts) is disabled, so the caller must not
- * sleep, and is advised to release the hwspinlock as soon as possible. This is
- * required in order to minimize remote cores polling on the hardware
- * interconnect.
+ * If the mode is neither HWLOCK_IN_ATOMIC nor HWLOCK_RAW, upon a successful
+ * return from this function, preemption (and possibly interrupts) is disabled,
+ * so the caller must not sleep, and is advised to release the hwspinlock as
+ * soon as possible. This is required in order to minimize remote cores polling
+ * on the hardware interconnect.
  *
  * The user decides whether local interrupts are disabled or not, and if yes,
  * whether he wants their previous state to be saved. It is up to the user
@@ -112,6 +116,7 @@
 		ret = spin_trylock_irq(&hwlock->lock);
 		break;
 	case HWLOCK_RAW:
+	case HWLOCK_IN_ATOMIC:
 		ret = 1;
 		break;
 	default:
@@ -136,6 +141,7 @@
 			spin_unlock_irq(&hwlock->lock);
 			break;
 		case HWLOCK_RAW:
+		case HWLOCK_IN_ATOMIC:
 			/* Nothing to do */
 			break;
 		default:
@@ -179,11 +185,14 @@
  * user need some time-consuming or sleepable operations under the hardware
  * lock, they need one sleepable lock (like mutex) to protect the operations.
  *
- * If the mode is not HWLOCK_RAW, upon a successful return from this function,
- * preemption is disabled (and possibly local interrupts, too), so the caller
- * must not sleep, and is advised to release the hwspinlock as soon as possible.
- * This is required in order to minimize remote cores polling on the
- * hardware interconnect.
+ * If the mode is HWLOCK_IN_ATOMIC (called from an atomic context) the timeout
+ * is handled with busy-waiting delays, hence shall not exceed few msecs.
+ *
+ * If the mode is neither HWLOCK_IN_ATOMIC nor HWLOCK_RAW, upon a successful
+ * return from this function, preemption (and possibly interrupts) is disabled,
+ * so the caller must not sleep, and is advised to release the hwspinlock as
+ * soon as possible. This is required in order to minimize remote cores polling
+ * on the hardware interconnect.
  *
  * The user decides whether local interrupts are disabled or not, and if yes,
  * whether he wants their previous state to be saved. It is up to the user
@@ -198,7 +207,7 @@
 					int mode, unsigned long *flags)
 {
 	int ret;
-	unsigned long expire;
+	unsigned long expire, atomic_delay = 0;
 
 	expire = msecs_to_jiffies(to) + jiffies;
 
@@ -212,8 +221,15 @@
 		 * The lock is already taken, let's check if the user wants
 		 * us to try again
 		 */
-		if (time_is_before_eq_jiffies(expire))
-			return -ETIMEDOUT;
+		if (mode == HWLOCK_IN_ATOMIC) {
+			udelay(HWSPINLOCK_RETRY_DELAY_US);
+			atomic_delay += HWSPINLOCK_RETRY_DELAY_US;
+			if (atomic_delay > to * 1000)
+				return -ETIMEDOUT;
+		} else {
+			if (time_is_before_eq_jiffies(expire))
+				return -ETIMEDOUT;
+		}
 
 		/*
 		 * Allow platform-specific relax handlers to prevent
@@ -276,6 +292,7 @@
 		spin_unlock_irq(&hwlock->lock);
 		break;
 	case HWLOCK_RAW:
+	case HWLOCK_IN_ATOMIC:
 		/* Nothing to do */
 		break;
 	default:
@@ -333,6 +350,11 @@
 	if (ret)
 		return ret;
 
+	if (!of_device_is_available(args.np)) {
+		ret = -ENOENT;
+		goto out;
+	}
+
 	/* Find the hwspinlock device: we need its base_id */
 	ret = -EPROBE_DEFER;
 	rcu_read_lock();
diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c
index 625844e..14e1a53 100644
--- a/drivers/hwspinlock/omap_hwspinlock.c
+++ b/drivers/hwspinlock/omap_hwspinlock.c
@@ -140,6 +140,9 @@
 	if (ret)
 		goto reg_fail;
 
+	dev_dbg(&pdev->dev, "Registered %d locks with HwSpinlock core\n",
+		num_locks);
+
 	return 0;
 
 reg_fail:
@@ -171,6 +174,7 @@
 
 static const struct of_device_id omap_hwspinlock_of_match[] = {
 	{ .compatible = "ti,omap4-hwspinlock", },
+	{ .compatible = "ti,am654-hwspinlock", },
 	{ /* end */ },
 };
 MODULE_DEVICE_TABLE(of, omap_hwspinlock_of_match);
diff --git a/drivers/hwspinlock/stm32_hwspinlock.c b/drivers/hwspinlock/stm32_hwspinlock.c
new file mode 100644
index 0000000..c8eacf4
--- /dev/null
+++ b/drivers/hwspinlock/stm32_hwspinlock.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics SA 2018
+ * Author: Benjamin Gaignard <benjamin.gaignard@st.com> for STMicroelectronics.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/hwspinlock.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+#include "hwspinlock_internal.h"
+
+#define STM32_MUTEX_COREID	BIT(8)
+#define STM32_MUTEX_LOCK_BIT	BIT(31)
+#define STM32_MUTEX_NUM_LOCKS	32
+
+struct stm32_hwspinlock {
+	struct clk *clk;
+	struct hwspinlock_device bank;
+};
+
+static int stm32_hwspinlock_trylock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+	u32 status;
+
+	writel(STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID, lock_addr);
+	status = readl(lock_addr);
+
+	return status == (STM32_MUTEX_LOCK_BIT | STM32_MUTEX_COREID);
+}
+
+static void stm32_hwspinlock_unlock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+
+	writel(STM32_MUTEX_COREID, lock_addr);
+}
+
+static void stm32_hwspinlock_relax(struct hwspinlock *lock)
+{
+	ndelay(50);
+}
+
+static const struct hwspinlock_ops stm32_hwspinlock_ops = {
+	.trylock	= stm32_hwspinlock_trylock,
+	.unlock		= stm32_hwspinlock_unlock,
+	.relax		= stm32_hwspinlock_relax,
+};
+
+static int stm32_hwspinlock_probe(struct platform_device *pdev)
+{
+	struct stm32_hwspinlock *hw;
+	void __iomem *io_base;
+	struct resource *res;
+	size_t array_size;
+	int i, ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	io_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(io_base))
+		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);
+	if (!hw)
+		return -ENOMEM;
+
+	hw->clk = devm_clk_get(&pdev->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);
+
+	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);
+
+	if (ret)
+		pm_runtime_disable(&pdev->dev);
+
+	return ret;
+}
+
+static int stm32_hwspinlock_remove(struct platform_device *pdev)
+{
+	struct stm32_hwspinlock *hw = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = hwspin_lock_unregister(&hw->bank);
+	if (ret)
+		dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
+
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static int __maybe_unused stm32_hwspinlock_runtime_suspend(struct device *dev)
+{
+	struct stm32_hwspinlock *hw = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(hw->clk);
+
+	return 0;
+}
+
+static int __maybe_unused stm32_hwspinlock_runtime_resume(struct device *dev)
+{
+	struct stm32_hwspinlock *hw = dev_get_drvdata(dev);
+
+	clk_prepare_enable(hw->clk);
+
+	return 0;
+}
+
+static const struct dev_pm_ops stm32_hwspinlock_pm_ops = {
+	SET_RUNTIME_PM_OPS(stm32_hwspinlock_runtime_suspend,
+			   stm32_hwspinlock_runtime_resume,
+			   NULL)
+};
+
+static const struct of_device_id stm32_hwpinlock_ids[] = {
+	{ .compatible = "st,stm32-hwspinlock", },
+	{},
+};
+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,
+		.pm	= &stm32_hwspinlock_pm_ops,
+	},
+};
+
+static int __init stm32_hwspinlock_init(void)
+{
+	return platform_driver_register(&stm32_hwspinlock_driver);
+}
+/* board init code might need to reserve hwspinlocks for predefined purposes */
+postcore_initcall(stm32_hwspinlock_init);
+
+static void __exit stm32_hwspinlock_exit(void)
+{
+	platform_driver_unregister(&stm32_hwspinlock_driver);
+}
+module_exit(stm32_hwspinlock_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hardware spinlock driver for STM32 SoCs");
+MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");