From 76306f4272e036e600254a98bc291df50cedd949 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Fri, 14 Feb 2014 16:30:52 +0000 Subject: [PATCH] MIPS: introduce cpu_coherent_mask Add a mask of CPUs which are currently known to be operating coherently. This is setup initially to be all present CPUs, but in a subsequent patch CPUs in a MIPS Coherent Processing System will be cleared in this mask as they enter non-coherent idle states. This will be used in order to determine when a CPU within a CPS system may need to be powered back up, but may also be used in future to optimise away wakeups for cache operations or TLB invalidations. Signed-off-by: Paul Burton --- arch/mips/include/asm/smp.h | 3 +++ arch/mips/kernel/smp.c | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h index efa02acd3dd5..b037334fca22 100644 --- a/arch/mips/include/asm/smp.h +++ b/arch/mips/include/asm/smp.h @@ -46,6 +46,9 @@ extern int __cpu_logical_map[NR_CPUS]; extern volatile cpumask_t cpu_callin_map; +/* Mask of CPUs which are currently definitely operating coherently */ +extern cpumask_t cpu_coherent_mask; + extern void asmlinkage smp_bootstrap(void); /* diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index 9a5226443bc1..991ae968ef26 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -66,6 +66,8 @@ EXPORT_SYMBOL(cpu_sibling_map); /* representing cpus for which sibling maps can be computed */ static cpumask_t cpu_sibling_setup_map; +cpumask_t cpu_coherent_mask; + static inline void set_cpu_sibling_map(int cpu) { int i; @@ -124,6 +126,7 @@ asmlinkage void start_secondary(void) cpu = smp_processor_id(); cpu_data[cpu].udelay_val = loops_per_jiffy; + cpu_set(cpu, cpu_coherent_mask); notify_cpu_starting(cpu); set_cpu_online(cpu, true); @@ -186,6 +189,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus) #ifndef CONFIG_HOTPLUG_CPU init_cpu_present(cpu_possible_mask); #endif + cpumask_copy(&cpu_coherent_mask, cpu_possible_mask); } /* preload SMP state for boot cpu */ -- 2.11.0