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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-04 17:18:09 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-04 17:18:09 +0300 |
commit | a4fdb2a46f617b8b2cd47acec026ec16532edbc6 (patch) | |
tree | 8d993287c9337349034ce6bbe050f7ce016a5268 /arch/arm64/include/asm/spinlock.h | |
parent | 807249d3ada1ff28a47c4054ca4edd479421b671 (diff) | |
parent | 674c242c9323d3c293fc4f9a3a3a619fe3063290 (diff) | |
download | linux-a4fdb2a46f617b8b2cd47acec026ec16532edbc6.tar.xz |
Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
- Support for new architectural features introduced in ARMv8.1:
* Privileged Access Never (PAN) to catch user pointer dereferences in
the kernel
* Large System Extension (LSE) for building scalable atomics and locks
(depends on locking/arch-atomic from tip, which is included here)
* Hardware Dirty Bit Management (DBM) for updating clean PTEs
automatically
- Move our PSCI implementation out into drivers/firmware/, where it can
be shared with arch/arm/. RMK has also pulled this component branch
and has additional patches moving arch/arm/ over. MAINTAINERS is
updated accordingly.
- Better BUG implementation based on the BRK instruction for trapping
- Leaf TLB invalidation for unmapping user pages
- Support for PROBE_ONLY PCI configurations
- Various cleanups and non-critical fixes, including:
* Always flush FP/SIMD state over exec()
* Restrict memblock additions based on range of linear mapping
* Ensure *(LIST_POISON) generates a fatal fault
* Context-tracking syscall return no longer corrupts return value when
not forced on.
* Alternatives patching synchronisation/stability improvements
* Signed sub-word cmpxchg compare fix (tickled by HAVE_CMPXCHG_LOCAL)
* Force SMP=y
* Hide direct DCC access from userspace
* Fix EFI stub memory allocation when DRAM starts at 0x0
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits)
arm64: flush FP/SIMD state correctly after execve()
arm64: makefile: fix perf_callchain.o kconfig dependency
arm64: set MAX_MEMBLOCK_ADDR according to linear region size
of/fdt: make memblock maximum physical address arch configurable
arm64: Fix source code file path in comments
arm64: entry: always restore x0 from the stack on syscall return
arm64: mdscr_el1: avoid exposing DCC to userspace
arm64: kconfig: Move LIST_POISON to a safe value
arm64: Add __exception_irq_entry definition for function graph
arm64: mm: ensure patched kernel text is fetched from PoU
arm64: alternatives: ensure secondary CPUs execute ISB after patching
arm64: make ll/sc __cmpxchg_case_##name asm consistent
arm64: dma-mapping: Simplify pgprot handling
arm64: restore cpu suspend/resume functionality
ARM64: PCI: do not enable resources on PROBE_ONLY systems
arm64: cmpxchg: truncate sub-word signed types before comparison
arm64: alternative: put secondary CPUs into polling loop during patch
arm64/Documentation: clarify wording regarding memory below the Image
arm64: lse: fix lse cmpxchg code indentation
arm64: remove redundant object file list
...
Diffstat (limited to 'arch/arm64/include/asm/spinlock.h')
-rw-r--r-- | arch/arm64/include/asm/spinlock.h | 147 |
1 files changed, 114 insertions, 33 deletions
diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h index cee128732435..c85e96d174a5 100644 --- a/arch/arm64/include/asm/spinlock.h +++ b/arch/arm64/include/asm/spinlock.h @@ -16,6 +16,7 @@ #ifndef __ASM_SPINLOCK_H #define __ASM_SPINLOCK_H +#include <asm/lse.h> #include <asm/spinlock_types.h> #include <asm/processor.h> @@ -38,11 +39,21 @@ static inline void arch_spin_lock(arch_spinlock_t *lock) asm volatile( /* Atomically increment the next ticket. */ + ARM64_LSE_ATOMIC_INSN( + /* LL/SC */ " prfm pstl1strm, %3\n" "1: ldaxr %w0, %3\n" " add %w1, %w0, %w5\n" " stxr %w2, %w1, %3\n" -" cbnz %w2, 1b\n" +" cbnz %w2, 1b\n", + /* LSE atomics */ +" mov %w2, %w5\n" +" ldadda %w2, %w0, %3\n" +" nop\n" +" nop\n" +" nop\n" + ) + /* Did we get the lock? */ " eor %w1, %w0, %w0, ror #16\n" " cbz %w1, 3f\n" @@ -67,15 +78,25 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock) unsigned int tmp; arch_spinlock_t lockval; - asm volatile( -" prfm pstl1strm, %2\n" -"1: ldaxr %w0, %2\n" -" eor %w1, %w0, %w0, ror #16\n" -" cbnz %w1, 2f\n" -" add %w0, %w0, %3\n" -" stxr %w1, %w0, %2\n" -" cbnz %w1, 1b\n" -"2:" + asm volatile(ARM64_LSE_ATOMIC_INSN( + /* LL/SC */ + " prfm pstl1strm, %2\n" + "1: ldaxr %w0, %2\n" + " eor %w1, %w0, %w0, ror #16\n" + " cbnz %w1, 2f\n" + " add %w0, %w0, %3\n" + " stxr %w1, %w0, %2\n" + " cbnz %w1, 1b\n" + "2:", + /* LSE atomics */ + " ldr %w0, %2\n" + " eor %w1, %w0, %w0, ror #16\n" + " cbnz %w1, 1f\n" + " add %w1, %w0, %3\n" + " casa %w0, %w1, %2\n" + " and %w1, %w1, #0xffff\n" + " eor %w1, %w1, %w0, lsr #16\n" + "1:") : "=&r" (lockval), "=&r" (tmp), "+Q" (*lock) : "I" (1 << TICKET_SHIFT) : "memory"); @@ -85,10 +106,19 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock) static inline void arch_spin_unlock(arch_spinlock_t *lock) { - asm volatile( -" stlrh %w1, %0\n" - : "=Q" (lock->owner) - : "r" (lock->owner + 1) + unsigned long tmp; + + asm volatile(ARM64_LSE_ATOMIC_INSN( + /* LL/SC */ + " ldrh %w1, %0\n" + " add %w1, %w1, #1\n" + " stlrh %w1, %0", + /* LSE atomics */ + " mov %w1, #1\n" + " nop\n" + " staddlh %w1, %0") + : "=Q" (lock->owner), "=&r" (tmp) + : : "memory"); } @@ -123,13 +153,24 @@ static inline void arch_write_lock(arch_rwlock_t *rw) { unsigned int tmp; - asm volatile( + 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" + " nop", + /* 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"); @@ -139,11 +180,18 @@ static inline int arch_write_trylock(arch_rwlock_t *rw) { unsigned int tmp; - asm volatile( - " ldaxr %w0, %1\n" - " cbnz %w0, 1f\n" + asm volatile(ARM64_LSE_ATOMIC_INSN( + /* LL/SC */ + "1: ldaxr %w0, %1\n" + " cbnz %w0, 2f\n" " stxr %w0, %w2, %1\n" - "1:\n" + " cbnz %w0, 1b\n" + "2:", + /* LSE atomics */ + " mov %w0, wzr\n" + " casa %w0, %w2, %1\n" + " nop\n" + " nop") : "=&r" (tmp), "+Q" (rw->lock) : "r" (0x80000000) : "memory"); @@ -153,9 +201,10 @@ static inline int arch_write_trylock(arch_rwlock_t *rw) static inline void arch_write_unlock(arch_rwlock_t *rw) { - asm volatile( - " stlr %w1, %0\n" - : "=Q" (rw->lock) : "r" (0) : "memory"); + asm volatile(ARM64_LSE_ATOMIC_INSN( + " stlr wzr, %0", + " swpl wzr, wzr, %0") + : "=Q" (rw->lock) :: "memory"); } /* write_can_lock - would write_trylock() succeed? */ @@ -172,6 +221,10 @@ static inline void arch_write_unlock(arch_rwlock_t *rw) * * 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) { @@ -179,26 +232,43 @@ static inline void arch_read_lock(arch_rwlock_t *rw) 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" + " nop\n" + " cbnz %w1, 2b", + /* 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) : - : "memory"); + : "cc", "memory"); } static inline void arch_read_unlock(arch_rwlock_t *rw) { unsigned int tmp, tmp2; - asm volatile( + 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\n" + " cbnz %w1, 1b", + /* LSE atomics */ + " movn %w0, #0\n" + " nop\n" + " nop\n" + " staddl %w0, %2") : "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock) : : "memory"); @@ -206,17 +276,28 @@ static inline void arch_read_unlock(arch_rwlock_t *rw) static inline int arch_read_trylock(arch_rwlock_t *rw) { - unsigned int tmp, tmp2 = 1; + unsigned int tmp, tmp2; - asm volatile( - " ldaxr %w0, %2\n" + 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, 1f\n" + " tbnz %w0, #31, 2f\n" " stxr %w1, %w0, %2\n" - "1:\n" - : "=&r" (tmp), "+r" (tmp2), "+Q" (rw->lock) + " 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" + " nop\n" + "1:") + : "=&r" (tmp), "=&r" (tmp2), "+Q" (rw->lock) : - : "memory"); + : "cc", "memory"); return !tmp2; } |