Merge tag 'hwlock-v5.3' of git://github.com/andersson/remoteproc

Pull hwspinlock updates from Bjorn Andersson:
 "This contains support for hardware spinlock TI K3 AM65x and J721E
  family of SoCs, support for using hwspinlocks from atomic context and
  better error reporting when dealing with hardware disabled in
  DeviceTree"

* tag 'hwlock-v5.3' of git://github.com/andersson/remoteproc:
  hwspinlock: add the 'in_atomic' API
  hwspinlock: document the hwspinlock 'raw' API
  hwspinlock: stm32: implement the relax() ops
  hwspinlock: ignore disabled device
  hwspinlock/omap: Add a trace during probe
  hwspinlock/omap: Add support for TI K3 SoCs
  dt-bindings: hwlock: Update OMAP binding for TI K3 SoCs

1 files changed, 58 insertions, 3 deletions

diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h
index 0afe693be5f4..bfe7c1f1ac6d 100644
--- a/include/linux/hwspinlock.h
+++ b/include/linux/hwspinlock.h
@@ -14,9 +14,10 @@
 #include <linux/sched.h>
 
 /* hwspinlock mode argument */
-#define HWLOCK_IRQSTATE	0x01	/* Disable interrupts, save state */
-#define HWLOCK_IRQ	0x02	/* Disable interrupts, don't save state */
-#define HWLOCK_RAW	0x03
+#define HWLOCK_IRQSTATE		0x01 /* Disable interrupts, save state */
+#define HWLOCK_IRQ		0x02 /* Disable interrupts, don't save state */
+#define HWLOCK_RAW		0x03
+#define HWLOCK_IN_ATOMIC	0x04 /* Called while in atomic context */
 
 struct device;
 struct device_node;
@@ -223,6 +224,23 @@ static inline int hwspin_trylock_raw(struct hwspinlock *hwlock)
 }
 
 /**
+ * hwspin_trylock_in_atomic() - attempt to lock a specific hwspinlock
+ * @hwlock: an hwspinlock which we want to trylock
+ *
+ * This function attempts to lock an hwspinlock, and will immediately fail
+ * if the hwspinlock is already taken.
+ *
+ * This function shall be called only from an atomic context.
+ *
+ * Returns 0 if we successfully locked the hwspinlock, -EBUSY if
+ * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid.
+ */
+static inline int hwspin_trylock_in_atomic(struct hwspinlock *hwlock)
+{
+	return __hwspin_trylock(hwlock, HWLOCK_IN_ATOMIC, NULL);
+}
+
+/**
  * hwspin_trylock() - attempt to lock a specific hwspinlock
  * @hwlock: an hwspinlock which we want to trylock
  *
@@ -313,6 +331,28 @@ int hwspin_lock_timeout_raw(struct hwspinlock *hwlock, unsigned int to)
 }
 
 /**
+ * hwspin_lock_timeout_in_atomic() - lock an hwspinlock with timeout limit
+ * @hwlock: the hwspinlock to be locked
+ * @to: timeout value in msecs
+ *
+ * This function locks the underlying @hwlock. If the @hwlock
+ * is already taken, the function will busy loop waiting for it to
+ * be released, but give up when @timeout msecs have elapsed.
+ *
+ * This function shall be called only from an atomic context and the timeout
+ * value shall not exceed a few msecs.
+ *
+ * Returns 0 when the @hwlock was successfully taken, and an appropriate
+ * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still
+ * busy after @timeout msecs). The function will never sleep.
+ */
+static inline
+int hwspin_lock_timeout_in_atomic(struct hwspinlock *hwlock, unsigned int to)
+{
+	return __hwspin_lock_timeout(hwlock, to, HWLOCK_IN_ATOMIC, NULL);
+}
+
+/**
  * hwspin_lock_timeout() - lock an hwspinlock with timeout limit
  * @hwlock: the hwspinlock to be locked
  * @to: timeout value in msecs
@@ -387,6 +427,21 @@ static inline void hwspin_unlock_raw(struct hwspinlock *hwlock)
 }
 
 /**
+ * hwspin_unlock_in_atomic() - unlock hwspinlock
+ * @hwlock: a previously-acquired hwspinlock which we want to unlock
+ *
+ * This function will unlock a specific hwspinlock.
+ *
+ * @hwlock must be already locked (e.g. by hwspin_trylock()) before calling
+ * this function: it is a bug to call unlock on a @hwlock that is already
+ * unlocked.
+ */
+static inline void hwspin_unlock_in_atomic(struct hwspinlock *hwlock)
+{
+	__hwspin_unlock(hwlock, HWLOCK_IN_ATOMIC, NULL);
+}
+
+/**
  * hwspin_unlock() - unlock hwspinlock
  * @hwlock: a previously-acquired hwspinlock which we want to unlock
  *