Hi Palmer, On Sat, Mar 19, 2022 at 6:48 AM Palmer Dabbelt <palmer@xxxxxxxxxxxx> wrote: > > On Fri, 18 Mar 2022 01:34:21 PDT (-0700), guoren@xxxxxxxxxx wrote: > > From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> > > > > 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@xxxxxxxxxxxxxxxxx> > > Cc: Palmer Dabbelt <palmer@xxxxxxxxxxxx> > > Thanks, one less port to look at ;) > > Looks like there were a few comments on the v1, and I wasn't going to > target this at the upcoming merge window anyway because I wanted to give Agree, we needn't so hurry. > the various RISC-V vendors time to test stuff. LMK if you want me to > add this to the others, but I was planning on posting a stable tag > either way so no big deal on my end. Yes, I hope csky's could be in the series. And I updated V2 with Arnd's suggestion, please have a look: https://lore.kernel.org/linux-arch/20220319035457.2214979-1-guoren@xxxxxxxxxx/T/#t > > > --- > > arch/csky/include/asm/Kbuild | 2 + > > arch/csky/include/asm/spinlock.h | 82 +------------------------- > > arch/csky/include/asm/spinlock_types.h | 20 +------ > > 3 files changed, 4 insertions(+), 100 deletions(-) > > > > diff --git a/arch/csky/include/asm/Kbuild b/arch/csky/include/asm/Kbuild > > index 904a18a818be..d94434288c31 100644 > > --- a/arch/csky/include/asm/Kbuild > > +++ b/arch/csky/include/asm/Kbuild > > @@ -3,6 +3,8 @@ generic-y += asm-offsets.h > > generic-y += extable.h > > generic-y += gpio.h > > generic-y += kvm_para.h > > +generic-y += ticket-lock.h > > +generic-y += ticket-lock-types.h > > generic-y += qrwlock.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 > > index 69f5aa249c5f..8bc179ba0d8d 100644 > > --- a/arch/csky/include/asm/spinlock.h > > +++ b/arch/csky/include/asm/spinlock.h > > @@ -3,87 +3,7 @@ > > #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/ticket-lock.h> > > #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 > > index db87a12c3827..0bb7f6022a3b 100644 > > --- a/arch/csky/include/asm/spinlock_types.h > > +++ b/arch/csky/include/asm/spinlock_types.h > > @@ -3,25 +3,7 @@ > > #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/ticket-lock-types.h> > > #include <asm-generic/qrwlock_types.h> > > > > #endif /* __ASM_CSKY_SPINLOCK_TYPES_H */ -- Best Regards Guo Ren ML: https://lore.kernel.org/linux-csky/
