New patch to review for coreboot: Add a lock with timeout

[Bora Guvendik]

Bora Guvendik ([e-mail]) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/18107

-gerrit

commit fa28608c185eeb6f6ef98811683ee0cc39724a5a
Author: Bora Guvendik 
Date:   Wed Jan 4 16:51:31 2017 -0800

Add a lock with timeout

In case something goes wrong on one of the
    cpus, add the ability to use a lock with
    timeout so that other cpus don't wait forever.
    Turn lock and release into apis

BUG=chrome-os-partner:59875
    BRANCH=reef
    TEST=None

Change-Id: Iab6bd30ddf7632c7a5785b338798960c26016b24
    Signed-off-by: Bora Guvendik 
---
 src/cpu/x86/mp_init.c    | 21 +++++++++++++++++++--
 src/include/cpu/x86/mp.h |  6 ++++++
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/src/cpu/x86/mp_init.c b/src/cpu/x86/mp_init.c
index c989963..f137ede 100644
--- a/src/cpu/x86/mp_init.c
+++ b/src/cpu/x86/mp_init.c
@@ -138,7 +138,7 @@ struct cpu_map {
 /* Keep track of APIC and device structure for each CPU. */
 static struct cpu_map cpus[CONFIG_MAX_CPUS];

-static inline void barrier_wait(atomic_t *b)
+inline void barrier_wait(atomic_t *b)
 {
    while (atomic_read(b) == 0) {
    	asm ("pause");
@@ -146,7 +146,24 @@ static inline void barrier_wait(atomic_t *b)
    mfence();
 }

-static inline void release_barrier(atomic_t *b)
+inline void barrier_wait_timeout(atomic_t *b, uint32_t timeout_ms)
+{
+	struct mono_time current, end;
+
+	timer_monotonic_get(&current);
+	end = current;
+	mono_time_add_msecs(&end, timeout_ms);
+
+	while (atomic_read(b) == 0) {
+		timer_monotonic_get(&current);
+		if (mono_time_after(&current, &end))
+			break;
+		asm ("pause");
+	}
+	mfence();
+}
+
+inline void release_barrier(atomic_t *b)
 {
    mfence();
    atomic_set(b, 1);
diff --git a/src/include/cpu/x86/mp.h b/src/include/cpu/x86/mp.h
index b9b4d57..113ed84 100644
--- a/src/include/cpu/x86/mp.h
+++ b/src/include/cpu/x86/mp.h
@@ -151,4 +151,10 @@ void smm_initiate_relocation_parallel(void);
 /* Send SMI to self with single execution. */
 void smm_initiate_relocation(void);

+inline void barrier_wait(atomic_t *b);
+
+inline void release_barrier(atomic_t *b);
+
+inline void barrier_wait_timeout(atomic_t *b, uint32_t timeout_ms);
+
 #endif /* _X86_MP_H_ */