diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2020-07-26 05:51:53 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-07-29 13:02:09 +0200 |
| commit | 1f0ce497433f8944045ee1baae218e31a0d295ee (patch) | |
| tree | 3af5536dbcfef275ad6a1c7eb78e06661c5bf285 /arch/powerpc/include/asm/dbell.h | |
| parent | powerpc/perf: Fix MMCRA_BHRB_DISABLE define for binutils < 2.28 (diff) | |
| download | linux-1f0ce497433f8944045ee1baae218e31a0d295ee.tar.xz linux-1f0ce497433f8944045ee1baae218e31a0d295ee.zip | |
powerpc: Inline doorbell sending functions
These are only called in one place for a given platform, so inline
them for performance.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Tested-by: Cédric Le Goater <clg@kaod.org>
[mpe: Fix build errors related to KVM]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200726035155.1424103-2-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/include/asm/dbell.h')
| -rw-r--r-- | arch/powerpc/include/asm/dbell.h | 64 |
1 files changed, 61 insertions, 3 deletions
diff --git a/arch/powerpc/include/asm/dbell.h b/arch/powerpc/include/asm/dbell.h index 4ce6808deed3..3e9da22a2779 100644 --- a/arch/powerpc/include/asm/dbell.h +++ b/arch/powerpc/include/asm/dbell.h @@ -11,8 +11,10 @@ #include <linux/smp.h> #include <linux/threads.h> +#include <asm/cputhreads.h> #include <asm/ppc-opcode.h> #include <asm/feature-fixups.h> +#include <asm/kvm_ppc.h> #define PPC_DBELL_MSG_BRDCAST (0x04000000) #define PPC_DBELL_TYPE(x) (((x) & 0xf) << (63-36)) @@ -87,9 +89,6 @@ static inline void ppc_msgsync(void) #endif /* CONFIG_PPC_BOOK3S */ -extern void doorbell_global_ipi(int cpu); -extern void doorbell_core_ipi(int cpu); -extern int doorbell_try_core_ipi(int cpu); extern void doorbell_exception(struct pt_regs *regs); static inline void ppc_msgsnd(enum ppc_dbell type, u32 flags, u32 tag) @@ -100,4 +99,63 @@ static inline void ppc_msgsnd(enum ppc_dbell type, u32 flags, u32 tag) _ppc_msgsnd(msg); } +#ifdef CONFIG_SMP + +/* + * Doorbells must only be used if CPU_FTR_DBELL is available. + * msgsnd is used in HV, and msgsndp is used in !HV. + * + * These should be used by platform code that is aware of restrictions. + * Other arch code should use ->cause_ipi. + * + * doorbell_global_ipi() sends a dbell to any target CPU. + * Must be used only by architectures that address msgsnd target + * by PIR/get_hard_smp_processor_id. + */ +static inline void doorbell_global_ipi(int cpu) +{ + u32 tag = get_hard_smp_processor_id(cpu); + + kvmppc_set_host_ipi(cpu); + /* Order previous accesses vs. msgsnd, which is treated as a store */ + ppc_msgsnd_sync(); + ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag); +} + +/* + * doorbell_core_ipi() sends a dbell to a target CPU in the same core. + * Must be used only by architectures that address msgsnd target + * by TIR/cpu_thread_in_core. + */ +static inline void doorbell_core_ipi(int cpu) +{ + u32 tag = cpu_thread_in_core(cpu); + + kvmppc_set_host_ipi(cpu); + /* Order previous accesses vs. msgsnd, which is treated as a store */ + ppc_msgsnd_sync(); + ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag); +} + +/* + * Attempt to cause a core doorbell if destination is on the same core. + * Returns 1 on success, 0 on failure. + */ +static inline int doorbell_try_core_ipi(int cpu) +{ + int this_cpu = get_cpu(); + int ret = 0; + + if (cpumask_test_cpu(cpu, cpu_sibling_mask(this_cpu))) { + doorbell_core_ipi(cpu); + ret = 1; + } + + put_cpu(); + + return ret; +} + +#endif /* CONFIG_SMP */ + #endif /* _ASM_POWERPC_DBELL_H */ |