Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx> --- arch/powerpc/include/asm/paravirt.h | 61 +++++++++++++++++++++++++++++ arch/powerpc/include/asm/spinlock.h | 24 +----------- arch/powerpc/lib/locks.c | 12 +++--- 3 files changed, 68 insertions(+), 29 deletions(-) create mode 100644 arch/powerpc/include/asm/paravirt.h diff --git a/arch/powerpc/include/asm/paravirt.h b/arch/powerpc/include/asm/paravirt.h new file mode 100644 index 000000000000..7a8546660a63 --- /dev/null +++ b/arch/powerpc/include/asm/paravirt.h @@ -0,0 +1,61 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef __ASM_PARAVIRT_H +#define __ASM_PARAVIRT_H +#ifdef __KERNEL__ + +#include <linux/jump_label.h> +#include <asm/smp.h> +#ifdef CONFIG_PPC64 +#include <asm/paca.h> +#include <asm/hvcall.h> +#endif + +#ifdef CONFIG_PPC_SPLPAR +DECLARE_STATIC_KEY_FALSE(shared_processor); + +static inline bool is_shared_processor(void) +{ + return static_branch_unlikely(&shared_processor); +} + +/* If bit 0 is set, the cpu has been preempted */ +static inline u32 yield_count_of(int cpu) +{ + __be32 yield_count = READ_ONCE(lppaca_of(cpu).yield_count); + return be32_to_cpu(yield_count); +} + +static inline void yield_to_preempted(int cpu, u32 yield_count) +{ + plpar_hcall_norets(H_CONFER, get_hard_smp_processor_id(cpu), yield_count); +} +#else +static inline bool is_shared_processor(void) +{ + return false; +} + +static inline u32 yield_count_of(int cpu) +{ + return 0; +} + +extern void ___bad_yield_to_preempted(void); +static inline void yield_to_preempted(int cpu, u32 yield_count) +{ + ___bad_yield_to_preempted(); /* This would be a bug */ +} +#endif + +#define vcpu_is_preempted vcpu_is_preempted +static inline bool vcpu_is_preempted(int cpu) +{ + if (!is_shared_processor()) + return false; + if (yield_count_of(cpu) & 1) + return true; + return false; +} + +#endif /* __KERNEL__ */ +#endif /* __ASM_PARAVIRT_H */ diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h index 2d620896cdae..79be9bb10bbb 100644 --- a/arch/powerpc/include/asm/spinlock.h +++ b/arch/powerpc/include/asm/spinlock.h @@ -15,11 +15,10 @@ * * (the type definitions are in asm/spinlock_types.h) */ -#include <linux/jump_label.h> #include <linux/irqflags.h> +#include <asm/paravirt.h> #ifdef CONFIG_PPC64 #include <asm/paca.h> -#include <asm/hvcall.h> #endif #include <asm/synch.h> #include <asm/ppc-opcode.h> @@ -35,18 +34,6 @@ #define LOCK_TOKEN 1 #endif -#ifdef CONFIG_PPC_PSERIES -DECLARE_STATIC_KEY_FALSE(shared_processor); - -#define vcpu_is_preempted vcpu_is_preempted -static inline bool vcpu_is_preempted(int cpu) -{ - if (!static_branch_unlikely(&shared_processor)) - return false; - return !!(be32_to_cpu(lppaca_of(cpu).yield_count) & 1); -} -#endif - static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock) { return lock.slock == 0; @@ -110,15 +97,6 @@ static inline void splpar_spin_yield(arch_spinlock_t *lock) {}; static inline void splpar_rw_yield(arch_rwlock_t *lock) {}; #endif -static inline bool is_shared_processor(void) -{ -#ifdef CONFIG_PPC_SPLPAR - return static_branch_unlikely(&shared_processor); -#else - return false; -#endif -} - static inline void spin_yield(arch_spinlock_t *lock) { if (is_shared_processor()) diff --git a/arch/powerpc/lib/locks.c b/arch/powerpc/lib/locks.c index 6440d5943c00..04165b7a163f 100644 --- a/arch/powerpc/lib/locks.c +++ b/arch/powerpc/lib/locks.c @@ -27,14 +27,14 @@ void splpar_spin_yield(arch_spinlock_t *lock) return; holder_cpu = lock_value & 0xffff; BUG_ON(holder_cpu >= NR_CPUS); - yield_count = be32_to_cpu(lppaca_of(holder_cpu).yield_count); + + yield_count = yield_count_of(holder_cpu); if ((yield_count & 1) == 0) return; /* virtual cpu is currently running */ rmb(); if (lock->slock != lock_value) return; /* something has changed */ - plpar_hcall_norets(H_CONFER, - get_hard_smp_processor_id(holder_cpu), yield_count); + yield_to_preempted(holder_cpu, yield_count); } EXPORT_SYMBOL_GPL(splpar_spin_yield); @@ -53,13 +53,13 @@ void splpar_rw_yield(arch_rwlock_t *rw) return; /* no write lock at present */ holder_cpu = lock_value & 0xffff; BUG_ON(holder_cpu >= NR_CPUS); - yield_count = be32_to_cpu(lppaca_of(holder_cpu).yield_count); + + yield_count = yield_count_of(holder_cpu); if ((yield_count & 1) == 0) return; /* virtual cpu is currently running */ rmb(); if (rw->lock != lock_value) return; /* something has changed */ - plpar_hcall_norets(H_CONFER, - get_hard_smp_processor_id(holder_cpu), yield_count); + yield_to_preempted(holder_cpu, yield_count); } #endif -- 2.23.0