From b866cc2199d6a6cdcefe4acfe4cfca3ac3c6d38e Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Thu, 13 Apr 2017 20:16:21 +1000 Subject: powerpc: Change the doorbell IPI calling convention Change the doorbell callers to know about their msgsnd addressing, rather than have them set a per-cpu target data tag at boot that gets sent to the cause_ipi functions. The data is only used for doorbell IPI functions, no other IPI types, so it makes sense to keep that detail local to doorbell. Have the platform code understand doorbell IPIs, rather than the interrupt controller code understand them. Platform code can look at capabilities it has available and decide which to use. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/dbell.c | 52 ++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 47 insertions(+), 5 deletions(-) (limited to 'arch/powerpc/kernel/dbell.c') diff --git a/arch/powerpc/kernel/dbell.c b/arch/powerpc/kernel/dbell.c index 2128f3a96c32..5869c66adfd0 100644 --- a/arch/powerpc/kernel/dbell.c +++ b/arch/powerpc/kernel/dbell.c @@ -20,18 +20,60 @@ #include #ifdef CONFIG_SMP -void doorbell_setup_this_cpu(void) + +/* + * 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. + */ +void doorbell_global_ipi(int cpu) { - unsigned long tag = mfspr(SPRN_DOORBELL_CPUTAG) & PPC_DBELL_TAG_MASK; + u32 tag = get_hard_smp_processor_id(cpu); - smp_muxed_ipi_set_data(smp_processor_id(), tag); + kvmppc_set_host_ipi(cpu, 1); + /* Order previous accesses vs. msgsnd, which is treated as a store */ + mb(); + ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, tag); } -void doorbell_cause_ipi(int cpu, unsigned long data) +/* + * 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. + */ +void doorbell_core_ipi(int cpu) { + u32 tag = cpu_thread_in_core(cpu); + + kvmppc_set_host_ipi(cpu, 1); /* Order previous accesses vs. msgsnd, which is treated as a store */ mb(); - ppc_msgsnd(PPC_DBELL_MSGTYPE, 0, data); + 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. + */ +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; } void doorbell_exception(struct pt_regs *regs) -- cgit v1.2.3