[coreboot-gerrit] Patch set updated for coreboot: cfd9738 arm64: add spinlock implementation

[Patrick Georgi (pgeorgi@google.com)]

Patrick Georgi (pgeorgi at google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9040

-gerrit

commit cfd973856f3dd8a5d9effeb5767a0bfc278b6754
Author: Aaron Durbin <adurbin at chromium.org>
Date:   Sat Sep 6 01:24:38 2014 -0500

    arm64: add spinlock implementation
    
    Provide a simple spinlock implentation for arm64. A value
    of 0 is unlocked and a value of 1 is locked.
    
    BUG=chrome-os-partner:31761
    BRANCH=None
    TEST=Built and ran SMP bringup on ryu.
    
    Change-Id: Ie88a715a6b51cd38a5fdd830583dae528cc49d67
    Signed-off-by: Patrick Georgi <pgeorgi at chromium.org>
    Original-Commit-Id: 14dab94610c96d6b1530c64d661833f8e613101c
    Original-Change-Id: I3bf2d80b91112d04442455ff0fa3f16900b7327f
    Original-Signed-off-by: Aaron Durbin <adurbin at chromium.org>
    Original-Reviewed-on: https://chromium-review.googlesource.com/216923
    Original-Reviewed-by: Furquan Shaikh <furquan at chromium.org>
---
 src/arch/arm64/include/armv8/arch/smp/spinlock.h | 25 +++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/arch/arm64/include/armv8/arch/smp/spinlock.h b/src/arch/arm64/include/armv8/arch/smp/spinlock.h
index 8a89d1f..10278e7 100644
--- a/src/arch/arm64/include/armv8/arch/smp/spinlock.h
+++ b/src/arch/arm64/include/armv8/arch/smp/spinlock.h
@@ -1,6 +1,29 @@
 #ifndef ARCH_SMP_SPINLOCK_H
 #define ARCH_SMP_SPINLOCK_H
 
-#error "spinlocks: implement this for ARM64"
+#include <arch/barrier.h>
+#include <stdint.h>
+
+typedef struct {
+	volatile uint32_t lock;
+} spinlock_t;
+
+#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 }
+#define DECLARE_SPIN_LOCK(x) static spinlock_t x = SPIN_LOCK_UNLOCKED;
+
+static inline void spin_lock(spinlock_t *spin)
+{
+	while (1) {
+		if (load_acquire_exclusive(&spin->lock) != 0)
+			continue;
+		if (store_release_exclusive(&spin->lock, 1))
+			break;
+	}
+}
+
+static inline void spin_unlock(spinlock_t *spin)
+{
+	store_release(&spin->lock, 0);
+}
 
 #endif