diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-11 17:42:32 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-11 17:42:32 -0800 |
commit | b3d6524ff7956c5a898d51a18eaecb62a60a2b84 (patch) | |
tree | cc049e7ec9edd9f5a76f286e04d8db9a1caa516a /arch/s390/lib/spinlock.c | |
parent | 07f80d41cf24b7e6e76cd97d420167932c9a7f82 (diff) | |
parent | 6a039eab53c01a58bfff95c78fc800ca7de27c77 (diff) |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky:
- The remaining patches for the z13 machine support: kernel build
option for z13, the cache synonym avoidance, SMT support,
compare-and-delay for spinloops and the CES5S crypto adapater.
- The ftrace support for function tracing with the gcc hotpatch option.
This touches common code Makefiles, Steven is ok with the changes.
- The hypfs file system gets an extension to access diagnose 0x0c data
in user space for performance analysis for Linux running under z/VM.
- The iucv hvc console gets wildcard spport for the user id filtering.
- The cacheinfo code is converted to use the generic infrastructure.
- Cleanup and bug fixes.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (42 commits)
s390/process: free vx save area when releasing tasks
s390/hypfs: Eliminate hypfs interval
s390/hypfs: Add diagnose 0c support
s390/cacheinfo: don't use smp_processor_id() in preemptible context
s390/zcrypt: fixed domain scanning problem (again)
s390/smp: increase maximum value of NR_CPUS to 512
s390/jump label: use different nop instruction
s390/jump label: add sanity checks
s390/mm: correct missing space when reporting user process faults
s390/dasd: cleanup profiling
s390/dasd: add locking for global_profile access
s390/ftrace: hotpatch support for function tracing
ftrace: let notrace function attribute disable hotpatching if necessary
ftrace: allow architectures to specify ftrace compile options
s390: reintroduce diag 44 calls for cpu_relax()
s390/zcrypt: Add support for new crypto express (CEX5S) adapter.
s390/zcrypt: Number of supported ap domains is not retrievable.
s390/spinlock: add compare-and-delay to lock wait loops
s390/tape: remove redundant if statement
s390/hvc_iucv: add simple wildcard matches to the iucv allow filter
...
Diffstat (limited to 'arch/s390/lib/spinlock.c')
-rw-r--r-- | arch/s390/lib/spinlock.c | 52 |
1 files changed, 45 insertions, 7 deletions
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c index 034a35a3e9c1..d6c9991f7797 100644 --- a/arch/s390/lib/spinlock.c +++ b/arch/s390/lib/spinlock.c @@ -12,7 +12,15 @@ #include <linux/smp.h> #include <asm/io.h> -int spin_retry = 1000; +int spin_retry = -1; + +static int __init spin_retry_init(void) +{ + if (spin_retry < 0) + spin_retry = MACHINE_HAS_CAD ? 10 : 1000; + return 0; +} +early_initcall(spin_retry_init); /** * spin_retry= parameter @@ -24,6 +32,11 @@ static int __init spin_retry_setup(char *str) } __setup("spin_retry=", spin_retry_setup); +static inline void _raw_compare_and_delay(unsigned int *lock, unsigned int old) +{ + asm(".insn rsy,0xeb0000000022,%0,0,%1" : : "d" (old), "Q" (*lock)); +} + void arch_spin_lock_wait(arch_spinlock_t *lp) { unsigned int cpu = SPINLOCK_LOCKVAL; @@ -46,6 +59,8 @@ void arch_spin_lock_wait(arch_spinlock_t *lp) /* Loop for a while on the lock value. */ count = spin_retry; do { + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&lp->lock, owner); owner = ACCESS_ONCE(lp->lock); } while (owner && count-- > 0); if (!owner) @@ -84,6 +99,8 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags) /* Loop for a while on the lock value. */ count = spin_retry; do { + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&lp->lock, owner); owner = ACCESS_ONCE(lp->lock); } while (owner && count-- > 0); if (!owner) @@ -100,11 +117,19 @@ EXPORT_SYMBOL(arch_spin_lock_wait_flags); int arch_spin_trylock_retry(arch_spinlock_t *lp) { + unsigned int cpu = SPINLOCK_LOCKVAL; + unsigned int owner; int count; - for (count = spin_retry; count > 0; count--) - if (arch_spin_trylock_once(lp)) - return 1; + for (count = spin_retry; count > 0; count--) { + owner = ACCESS_ONCE(lp->lock); + /* Try to get the lock if it is free. */ + if (!owner) { + if (_raw_compare_and_swap(&lp->lock, 0, cpu)) + return 1; + } else if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&lp->lock, owner); + } return 0; } EXPORT_SYMBOL(arch_spin_trylock_retry); @@ -126,8 +151,11 @@ void _raw_read_lock_wait(arch_rwlock_t *rw) } old = ACCESS_ONCE(rw->lock); owner = ACCESS_ONCE(rw->owner); - if ((int) old < 0) + if ((int) old < 0) { + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&rw->lock, old); continue; + } if (_raw_compare_and_swap(&rw->lock, old, old + 1)) return; } @@ -141,8 +169,11 @@ int _raw_read_trylock_retry(arch_rwlock_t *rw) while (count-- > 0) { old = ACCESS_ONCE(rw->lock); - if ((int) old < 0) + if ((int) old < 0) { + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&rw->lock, old); continue; + } if (_raw_compare_and_swap(&rw->lock, old, old + 1)) return 1; } @@ -173,6 +204,8 @@ void _raw_write_lock_wait(arch_rwlock_t *rw, unsigned int prev) } if ((old & 0x7fffffff) == 0 && (int) prev >= 0) break; + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&rw->lock, old); } } EXPORT_SYMBOL(_raw_write_lock_wait); @@ -201,6 +234,8 @@ void _raw_write_lock_wait(arch_rwlock_t *rw) smp_rmb(); if ((old & 0x7fffffff) == 0 && (int) prev >= 0) break; + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&rw->lock, old); } } EXPORT_SYMBOL(_raw_write_lock_wait); @@ -214,8 +249,11 @@ int _raw_write_trylock_retry(arch_rwlock_t *rw) while (count-- > 0) { old = ACCESS_ONCE(rw->lock); - if (old) + if (old) { + if (MACHINE_HAS_CAD) + _raw_compare_and_delay(&rw->lock, old); continue; + } if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000)) return 1; } |