From: Palmer Dabbelt <palmer@rivosinc.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Guo Ren <guoren@linux.alibaba.com>,
peterz@infradead.org, Palmer Dabbelt <palmer@rivosinc.com>,
guoren@kernel.org, jszhang@kernel.org,
linux-riscv@lists.infradead.org, Will Deacon <will@kernel.org>,
jonas@southpole.se, linux-csky@vger.kernel.org, mingo@redhat.com,
longman@redhat.com, linux-arch@vger.kernel.org,
aou@eecs.berkeley.edu, Arnd Bergmann <arnd@arndb.de>,
boqun.feng@gmail.com, openrisc@lists.librecores.org,
Paul Walmsley <paul.walmsley@sifive.com>,
Greg KH <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org, Palmer Dabbelt <palmer@dabbelt.com>,
sudipm.mukherjee@gmail.com, macro@orcam.me.uk
Subject: [PATCH v5 7/7] csky: Move to generic ticket-spinlock
Date: Mon, 9 May 2022 15:29:56 -0700 [thread overview]
Message-ID: <20220509222956.2886-8-palmer@rivosinc.com> (raw)
In-Reply-To: <20220509222956.2886-1-palmer@rivosinc.com>
From: Guo Ren <guoren@linux.alibaba.com>
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>
---
arch/csky/include/asm/Kbuild | 3 +
arch/csky/include/asm/spinlock.h | 89 --------------------------
arch/csky/include/asm/spinlock_types.h | 27 --------
3 files changed, 3 insertions(+), 116 deletions(-)
delete mode 100644 arch/csky/include/asm/spinlock.h
delete mode 100644 arch/csky/include/asm/spinlock_types.h
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 */
--
2.34.1
prev parent reply other threads:[~2022-05-09 22:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-09 22:29 [PATCH v5 0/7] Generic Ticket Spinlocks Palmer Dabbelt
2022-05-09 22:29 ` [PATCH v5 1/7] asm-generic: ticket-lock: New generic ticket-based spinlock Palmer Dabbelt
2022-05-09 22:29 ` [PATCH v5 2/7] asm-generic: qspinlock: Indicate the use of mixed-size atomics Palmer Dabbelt
2022-05-09 22:29 ` [PATCH v5 3/7] asm-generic: qrwlock: Document the spinlock fairness requirements Palmer Dabbelt
2022-05-09 22:29 ` [PATCH v5 4/7] openrisc: Move to ticket-spinlock Palmer Dabbelt
2022-05-09 22:29 ` [PATCH v5 5/7] RISC-V: Move to generic spinlocks Palmer Dabbelt
2022-05-09 22:29 ` [PATCH v5 6/7] RISC-V: Move to queued RW locks Palmer Dabbelt
2022-05-09 22:29 ` Palmer Dabbelt [this message]
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