diff options
author | Guo Ren <guoren@linux.alibaba.com> | 2022-03-18 09:34:21 +0100 |
---|---|---|
committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-05-11 20:50:15 +0200 |
commit | 9282d0996936c5fbf877c0d096a3feb456c878ad (patch) | |
tree | 6a5e92a9ebae7582f8c8a10353008ce6caea8407 /arch | |
parent | RISC-V: Move to queued RW locks (diff) | |
download | linux-9282d0996936c5fbf877c0d096a3feb456c878ad.tar.xz linux-9282d0996936c5fbf877c0d096a3feb456c878ad.zip |
csky: Move to generic ticket-spinlock
There is no benefit from custom implementation for ticket-spinlock,
so move to generic ticket-spinlock for easy maintenance.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/csky/include/asm/Kbuild | 3 | ||||
-rw-r--r-- | arch/csky/include/asm/spinlock.h | 89 | ||||
-rw-r--r-- | arch/csky/include/asm/spinlock_types.h | 27 |
3 files changed, 3 insertions, 116 deletions
diff --git a/arch/csky/include/asm/Kbuild b/arch/csky/include/asm/Kbuild index 888248235c23..103207a58f97 100644 --- a/arch/csky/include/asm/Kbuild +++ b/arch/csky/include/asm/Kbuild @@ -3,7 +3,10 @@ generic-y += asm-offsets.h generic-y += extable.h generic-y += gpio.h generic-y += kvm_para.h +generic-y += spinlock.h +generic-y += spinlock_types.h generic-y += qrwlock.h +generic-y += qrwlock_types.h generic-y += parport.h generic-y += user.h generic-y += vmlinux.lds.h diff --git a/arch/csky/include/asm/spinlock.h b/arch/csky/include/asm/spinlock.h deleted file mode 100644 index 69f5aa249c5f..000000000000 --- a/arch/csky/include/asm/spinlock.h +++ /dev/null @@ -1,89 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ - -#ifndef __ASM_CSKY_SPINLOCK_H -#define __ASM_CSKY_SPINLOCK_H - -#include <linux/spinlock_types.h> -#include <asm/barrier.h> - -/* - * Ticket-based spin-locking. - */ -static inline void arch_spin_lock(arch_spinlock_t *lock) -{ - arch_spinlock_t lockval; - u32 ticket_next = 1 << TICKET_NEXT; - u32 *p = &lock->lock; - u32 tmp; - - asm volatile ( - "1: ldex.w %0, (%2) \n" - " mov %1, %0 \n" - " add %0, %3 \n" - " stex.w %0, (%2) \n" - " bez %0, 1b \n" - : "=&r" (tmp), "=&r" (lockval) - : "r"(p), "r"(ticket_next) - : "cc"); - - while (lockval.tickets.next != lockval.tickets.owner) - lockval.tickets.owner = READ_ONCE(lock->tickets.owner); - - smp_mb(); -} - -static inline int arch_spin_trylock(arch_spinlock_t *lock) -{ - u32 tmp, contended, res; - u32 ticket_next = 1 << TICKET_NEXT; - u32 *p = &lock->lock; - - do { - asm volatile ( - " ldex.w %0, (%3) \n" - " movi %2, 1 \n" - " rotli %1, %0, 16 \n" - " cmpne %1, %0 \n" - " bt 1f \n" - " movi %2, 0 \n" - " add %0, %0, %4 \n" - " stex.w %0, (%3) \n" - "1: \n" - : "=&r" (res), "=&r" (tmp), "=&r" (contended) - : "r"(p), "r"(ticket_next) - : "cc"); - } while (!res); - - if (!contended) - smp_mb(); - - return !contended; -} - -static inline void arch_spin_unlock(arch_spinlock_t *lock) -{ - smp_mb(); - WRITE_ONCE(lock->tickets.owner, lock->tickets.owner + 1); -} - -static inline int arch_spin_value_unlocked(arch_spinlock_t lock) -{ - return lock.tickets.owner == lock.tickets.next; -} - -static inline int arch_spin_is_locked(arch_spinlock_t *lock) -{ - return !arch_spin_value_unlocked(READ_ONCE(*lock)); -} - -static inline int arch_spin_is_contended(arch_spinlock_t *lock) -{ - struct __raw_tickets tickets = READ_ONCE(lock->tickets); - - return (tickets.next - tickets.owner) > 1; -} -#define arch_spin_is_contended arch_spin_is_contended - -#include <asm/qrwlock.h> - -#endif /* __ASM_CSKY_SPINLOCK_H */ diff --git a/arch/csky/include/asm/spinlock_types.h b/arch/csky/include/asm/spinlock_types.h deleted file mode 100644 index db87a12c3827..000000000000 --- a/arch/csky/include/asm/spinlock_types.h +++ /dev/null @@ -1,27 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ - -#ifndef __ASM_CSKY_SPINLOCK_TYPES_H -#define __ASM_CSKY_SPINLOCK_TYPES_H - -#ifndef __LINUX_SPINLOCK_TYPES_RAW_H -# error "please don't include this file directly" -#endif - -#define TICKET_NEXT 16 - -typedef struct { - union { - u32 lock; - struct __raw_tickets { - /* little endian */ - u16 owner; - u16 next; - } tickets; - }; -} arch_spinlock_t; - -#define __ARCH_SPIN_LOCK_UNLOCKED { { 0 } } - -#include <asm-generic/qrwlock_types.h> - -#endif /* __ASM_CSKY_SPINLOCK_TYPES_H */ |