51 lines
2.0 KiB
Diff
51 lines
2.0 KiB
Diff
|
# HG changeset patch
|
||
|
|
# User Keir Fraser <keir.fraser@citrix.com>
|
||
|
|
# Date 1224519405 -3600
|
||
|
|
# Node ID 54d74fc0037ce688e79759ca632d3918f7aaa399
|
||
|
|
# Parent f4dab783b58b41f2c67a66d6d095887faec3c296
|
||
|
|
spinlock: Modify recursive spinlock definitions to support up to 4095 CPUs.
|
||
|
|
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
|
||
|
|
|
||
|
|
--- a/xen/include/asm-x86/spinlock.h
|
||
|
|
+++ b/xen/include/asm-x86/spinlock.h
|
||
|
|
@@ -8,11 +8,11 @@
|
||
|
|
|
||
|
|
typedef struct {
|
||
|
|
volatile s16 lock;
|
||
|
|
- s8 recurse_cpu;
|
||
|
|
- u8 recurse_cnt;
|
||
|
|
+ u16 recurse_cpu:12;
|
||
|
|
+ u16 recurse_cnt:4;
|
||
|
|
} spinlock_t;
|
||
|
|
|
||
|
|
-#define SPIN_LOCK_UNLOCKED /*(spinlock_t)*/ { 1, -1, 0 }
|
||
|
|
+#define SPIN_LOCK_UNLOCKED { 1, 0xfffu, 0 }
|
||
|
|
|
||
|
|
#define spin_lock_init(x) do { *(x) = (spinlock_t) SPIN_LOCK_UNLOCKED; } while(0)
|
||
|
|
#define spin_is_locked(x) (*(volatile char *)(&(x)->lock) <= 0)
|
||
|
|
@@ -59,11 +59,15 @@ static inline int _raw_spin_trylock(spin
|
||
|
|
#define _raw_spin_lock_recursive(_lock) \
|
||
|
|
do { \
|
||
|
|
int cpu = smp_processor_id(); \
|
||
|
|
+ /* Don't allow overflow of recurse_cpu field. */ \
|
||
|
|
+ BUILD_BUG_ON(NR_CPUS > 0xfffu); \
|
||
|
|
if ( likely((_lock)->recurse_cpu != cpu) ) \
|
||
|
|
{ \
|
||
|
|
spin_lock(_lock); \
|
||
|
|
(_lock)->recurse_cpu = cpu; \
|
||
|
|
} \
|
||
|
|
+ /* We support only fairly shallow recursion, else the counter overflows. */ \
|
||
|
|
+ ASSERT((_lock)->recurse_cnt < 0xfu); \
|
||
|
|
(_lock)->recurse_cnt++; \
|
||
|
|
} while ( 0 )
|
||
|
|
|
||
|
|
@@ -71,7 +75,7 @@ static inline int _raw_spin_trylock(spin
|
||
|
|
do { \
|
||
|
|
if ( likely(--(_lock)->recurse_cnt == 0) ) \
|
||
|
|
{ \
|
||
|
|
- (_lock)->recurse_cpu = -1; \
|
||
|
|
+ (_lock)->recurse_cpu = 0xfffu; \
|
||
|
|
spin_unlock(_lock); \
|
||
|
|
} \
|
||
|
|
} while ( 0 )
|