Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core locking updates from Ingo Molnar:
 "The main changes in this cycle are:

   - Another attempt at enabling cross-release lockdep dependency
     tracking (automatically part of CONFIG_PROVE_LOCKING=y), this time
     with better performance and fewer false positives. (Byungchul Park)

   - Introduce lockdep_assert_irqs_enabled()/disabled() and convert
     open-coded equivalents to lockdep variants. (Frederic Weisbecker)

   - Add down_read_killable() and use it in the VFS's iterate_dir()
     method. (Kirill Tkhai)

   - Convert remaining uses of ACCESS_ONCE() to
     READ_ONCE()/WRITE_ONCE(). Most of the conversion was Coccinelle
     driven. (Mark Rutland, Paul E. McKenney)

   - Get rid of lockless_dereference(), by strengthening Alpha atomics,
     strengthening READ_ONCE() with smp_read_barrier_depends() and thus
     being able to convert users of lockless_dereference() to
     READ_ONCE(). (Will Deacon)

   - Various micro-optimizations:

        - better PV qspinlocks (Waiman Long),
        - better x86 barriers (Michael S. Tsirkin)
        - better x86 refcounts (Kees Cook)

   - ... plus other fixes and enhancements. (Borislav Petkov, Juergen
     Gross, Miguel Bernal Marin)"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (70 commits)
  locking/x86: Use LOCK ADD for smp_mb() instead of MFENCE
  rcu: Use lockdep to assert IRQs are disabled/enabled
  netpoll: Use lockdep to assert IRQs are disabled/enabled
  timers/posix-cpu-timers: Use lockdep to assert IRQs are disabled/enabled
  sched/clock, sched/cputime: Use lockdep to assert IRQs are disabled/enabled
  irq_work: Use lockdep to assert IRQs are disabled/enabled
  irq/timings: Use lockdep to assert IRQs are disabled/enabled
  perf/core: Use lockdep to assert IRQs are disabled/enabled
  x86: Use lockdep to assert IRQs are disabled/enabled
  smp/core: Use lockdep to assert IRQs are disabled/enabled
  timers/hrtimer: Use lockdep to assert IRQs are disabled/enabled
  timers/nohz: Use lockdep to assert IRQs are disabled/enabled
  workqueue: Use lockdep to assert IRQs are disabled/enabled
  irq/softirqs: Use lockdep to assert IRQs are disabled/enabled
  locking/lockdep: Add IRQs disabled/enabled assertion APIs: lockdep_assert_irqs_enabled()/disabled()
  locking/pvqspinlock: Implement hybrid PV queued/unfair locks
  locking/rwlocks: Fix comments
  x86/paravirt: Set up the virt_spin_lock_key after static keys get initialized
  block, locking/lockdep: Assign a lock_class per gendisk used for wait_for_completion()
  workqueue: Remove now redundant lock acquisitions wrt. workqueue flushes
  ...
This commit is contained in:
Linus Torvalds 2017-11-13 12:38:26 -08:00
commit 8e9a2dba86
307 changed files with 1252 additions and 1672 deletions

View file

@ -22,7 +22,24 @@ config ARM64
select ARCH_HAS_STRICT_MODULE_RWX
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_HAVE_NMI_SAFE_CMPXCHG if ACPI_APEI_SEA
select ARCH_INLINE_READ_LOCK if !PREEMPT
select ARCH_INLINE_READ_LOCK_BH if !PREEMPT
select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPT
select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPT
select ARCH_INLINE_READ_UNLOCK if !PREEMPT
select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPT
select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPT
select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPT
select ARCH_INLINE_WRITE_LOCK if !PREEMPT
select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPT
select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPT
select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPT
select ARCH_INLINE_WRITE_UNLOCK if !PREEMPT
select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPT
select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPT
select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPT
select ARCH_USE_CMPXCHG_LOCKREF
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_SUPPORTS_MEMORY_FAILURE
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_NUMA_BALANCING

View file

@ -16,6 +16,7 @@ generic-y += mcs_spinlock.h
generic-y += mm-arch-hooks.h
generic-y += msi.h
generic-y += preempt.h
generic-y += qrwlock.h
generic-y += rwsem.h
generic-y += segment.h
generic-y += serial.h

View file

@ -27,8 +27,6 @@
* instructions.
*/
#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock)
static inline void arch_spin_lock(arch_spinlock_t *lock)
{
unsigned int tmp;
@ -139,176 +137,7 @@ static inline int arch_spin_is_contended(arch_spinlock_t *lock)
}
#define arch_spin_is_contended arch_spin_is_contended
/*
* Write lock implementation.
*
* Write locks set bit 31. Unlocking, is done by writing 0 since the lock is
* exclusively held.
*
* The memory barriers are implicit with the load-acquire and store-release
* instructions.
*/
static inline void arch_write_lock(arch_rwlock_t *rw)
{
unsigned int tmp;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" sevl\n"
"1: wfe\n"
"2: ldaxr %w0, %1\n"
" cbnz %w0, 1b\n"
" stxr %w0, %w2, %1\n"
" cbnz %w0, 2b\n"
__nops(1),
/* LSE atomics */
"1: mov %w0, wzr\n"
"2: casa %w0, %w2, %1\n"
" cbz %w0, 3f\n"
" ldxr %w0, %1\n"
" cbz %w0, 2b\n"
" wfe\n"
" b 1b\n"
"3:")
: "=&r" (tmp), "+Q" (rw->lock)
: "r" (0x80000000)
: "memory");
}
static inline int arch_write_trylock(arch_rwlock_t *rw)
{
unsigned int tmp;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
"1: ldaxr %w0, %1\n"
" cbnz %w0, 2f\n"
" stxr %w0, %w2, %1\n"
" cbnz %w0, 1b\n"
"2:",
/* LSE atomics */
" mov %w0, wzr\n"
" casa %w0, %w2, %1\n"
__nops(2))
: "=&r" (tmp), "+Q" (rw->lock)
: "r" (0x80000000)
: "memory");
return !tmp;
}
static inline void arch_write_unlock(arch_rwlock_t *rw)
{
asm volatile(ARM64_LSE_ATOMIC_INSN(
" stlr wzr, %0",
" swpl wzr, wzr, %0")
: "=Q" (rw->lock) :: "memory");
}
/* write_can_lock - would write_trylock() succeed? */
#define arch_write_can_lock(x) ((x)->lock == 0)
/*
* Read lock implementation.
*
* It exclusively loads the lock value, increments it and stores the new value
* back if positive and the CPU still exclusively owns the location. If the
* value is negative, the lock is already held.
*
* During unlocking there may be multiple active read locks but no write lock.
*
* The memory barriers are implicit with the load-acquire and store-release
* instructions.
*
* Note that in UNDEFINED cases, such as unlocking a lock twice, the LL/SC
* and LSE implementations may exhibit different behaviour (although this
* will have no effect on lockdep).
*/
static inline void arch_read_lock(arch_rwlock_t *rw)
{
unsigned int tmp, tmp2;
asm volatile(
" sevl\n"
ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
"1: wfe\n"
"2: ldaxr %w0, %2\n"
" add %w0, %w0, #1\n"
" tbnz %w0, #31, 1b\n"
" stxr %w1, %w0, %2\n"
" cbnz %w1, 2b\n"
__nops(1),
/* LSE atomics */
"1: wfe\n"
"2: ldxr %w0, %2\n"
" adds %w1, %w0, #1\n"
" tbnz %w1, #31, 1b\n"
" casa %w0, %w1, %2\n"
" sbc %w0, %w1, %w0\n"
" cbnz %w0, 2b")
: "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)
:
: "cc", "memory");
}
static inline void arch_read_unlock(arch_rwlock_t *rw)
{
unsigned int tmp, tmp2;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
"1: ldxr %w0, %2\n"
" sub %w0, %w0, #1\n"
" stlxr %w1, %w0, %2\n"
" cbnz %w1, 1b",
/* LSE atomics */
" movn %w0, #0\n"
" staddl %w0, %2\n"
__nops(2))
: "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)
:
: "memory");
}
static inline int arch_read_trylock(arch_rwlock_t *rw)
{
unsigned int tmp, tmp2;
asm volatile(ARM64_LSE_ATOMIC_INSN(
/* LL/SC */
" mov %w1, #1\n"
"1: ldaxr %w0, %2\n"
" add %w0, %w0, #1\n"
" tbnz %w0, #31, 2f\n"
" stxr %w1, %w0, %2\n"
" cbnz %w1, 1b\n"
"2:",
/* LSE atomics */
" ldr %w0, %2\n"
" adds %w1, %w0, #1\n"
" tbnz %w1, #31, 1f\n"
" casa %w0, %w1, %2\n"
" sbc %w1, %w1, %w0\n"
__nops(1)
"1:")
: "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock)
:
: "cc", "memory");
return !tmp2;
}
/* read_can_lock - would read_trylock() succeed? */
#define arch_read_can_lock(x) ((x)->lock < 0x80000000)
#define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
#define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
#define arch_spin_relax(lock) cpu_relax()
#define arch_read_relax(lock) cpu_relax()
#define arch_write_relax(lock) cpu_relax()
#include <asm/qrwlock.h>
/* See include/linux/spinlock.h */
#define smp_mb__after_spinlock() smp_mb()

View file

@ -36,10 +36,6 @@ typedef struct {
#define __ARCH_SPIN_LOCK_UNLOCKED { 0 , 0 }
typedef struct {
volatile unsigned int lock;
} arch_rwlock_t;
#define __ARCH_RW_LOCK_UNLOCKED { 0 }
#include <asm-generic/qrwlock_types.h>
#endif