Everything can be done even when CONFIG_SMP is not selected. Just use IS_ENABLED() where relevant and rely on GCC to opt out unneeded code and variables when CONFIG_SMP is not set.
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu> --- arch/powerpc/mm/nohash/mmu_context.c | 66 ++++++++++------------------ 1 file changed, 24 insertions(+), 42 deletions(-) diff --git a/arch/powerpc/mm/nohash/mmu_context.c b/arch/powerpc/mm/nohash/mmu_context.c index 75dafec50d19..437940d191d6 100644 --- a/arch/powerpc/mm/nohash/mmu_context.c +++ b/arch/powerpc/mm/nohash/mmu_context.c @@ -47,6 +47,7 @@ #include <asm/mmu_context.h> #include <asm/tlbflush.h> +#include <asm/smp.h> #include <mm/mmu_decl.h> @@ -86,9 +87,7 @@ void *abatron_pteptrs[2]; static unsigned int next_context, nr_free_contexts; static unsigned long *context_map; -#ifdef CONFIG_SMP static unsigned long *stale_map[NR_CPUS]; -#endif static struct mm_struct **context_mm; static DEFINE_RAW_SPINLOCK(context_lock); @@ -111,7 +110,6 @@ static DEFINE_RAW_SPINLOCK(context_lock); * the stale map as we can just flush the local CPU * -- benh */ -#ifdef CONFIG_SMP static unsigned int steal_context_smp(unsigned int id) { struct mm_struct *mm; @@ -164,14 +162,11 @@ static unsigned int steal_context_smp(unsigned int id) /* This will cause the caller to try again */ return MMU_NO_CONTEXT; } -#endif /* CONFIG_SMP */ static unsigned int steal_all_contexts(void) { struct mm_struct *mm; -#ifdef CONFIG_SMP int cpu = smp_processor_id(); -#endif unsigned int id; for (id = FIRST_CONTEXT; id <= LAST_CONTEXT; id++) { @@ -189,9 +184,8 @@ static unsigned int steal_all_contexts(void) mm->context.active = 0; #endif } -#ifdef CONFIG_SMP - __clear_bit(id, stale_map[cpu]); -#endif + if (IS_ENABLED(CONFIG_SMP)) + __clear_bit(id, stale_map[cpu]); } /* Flush the TLB for all contexts (not to be used on SMP) */ @@ -210,9 +204,7 @@ static unsigned int steal_all_contexts(void) static unsigned int steal_context_up(unsigned int id) { struct mm_struct *mm; -#ifdef CONFIG_SMP int cpu = smp_processor_id(); -#endif /* Pick up the victim mm */ mm = context_mm[id]; @@ -226,9 +218,8 @@ static unsigned int steal_context_up(unsigned int id) mm->context.id = MMU_NO_CONTEXT; /* XXX This clear should ultimately be part of local_flush_tlb_mm */ -#ifdef CONFIG_SMP - __clear_bit(id, stale_map[cpu]); -#endif + if (IS_ENABLED(CONFIG_SMP)) + __clear_bit(id, stale_map[cpu]); return id; } @@ -292,9 +283,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) { unsigned int id; -#ifdef CONFIG_SMP unsigned int i, cpu = smp_processor_id(); -#endif unsigned long *map; /* No lockless fast path .. yet */ @@ -303,17 +292,17 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, pr_hard("[%d] activating context for mm @%p, active=%d, id=%d", cpu, next, next->context.active, next->context.id); -#ifdef CONFIG_SMP - /* Mark us active and the previous one not anymore */ - next->context.active++; - if (prev) { - pr_hardcont(" (old=0x%p a=%d)", prev, prev->context.active); - WARN_ON(prev->context.active < 1); - prev->context.active--; + if (IS_ENABLED(CONFIG_SMP)) { + /* Mark us active and the previous one not anymore */ + next->context.active++; + if (prev) { + pr_hardcont(" (old=0x%p a=%d)", prev, prev->context.active); + WARN_ON(prev->context.active < 1); + prev->context.active--; + } } again: -#endif /* CONFIG_SMP */ /* If we already have a valid assigned context, skip all that */ id = next->context.id; @@ -334,14 +323,12 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, /* No more free contexts, let's try to steal one */ if (nr_free_contexts == 0) { -#ifdef CONFIG_SMP if (num_online_cpus() > 1) { id = steal_context_smp(id); if (id == MMU_NO_CONTEXT) goto again; goto stolen; } -#endif /* CONFIG_SMP */ if (IS_ENABLED(CONFIG_PPC_8xx)) id = steal_all_contexts(); else @@ -368,8 +355,7 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, /* If that context got marked stale on this CPU, then flush the * local TLB for it and unmark it before we use it */ -#ifdef CONFIG_SMP - if (test_bit(id, stale_map[cpu])) { + if (IS_ENABLED(CONFIG_SMP) && test_bit(id, stale_map[cpu])) { pr_hardcont(" | stale flush %d [%d..%d]", id, cpu_first_thread_sibling(cpu), cpu_last_thread_sibling(cpu)); @@ -383,7 +369,6 @@ void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, __clear_bit(id, stale_map[i]); } } -#endif /* Flick the MMU and release lock */ pr_hardcont(" -> %d\n", id); @@ -442,7 +427,6 @@ void destroy_context(struct mm_struct *mm) raw_spin_unlock_irqrestore(&context_lock, flags); } -#ifdef CONFIG_SMP static int mmu_ctx_cpu_prepare(unsigned int cpu) { /* We don't touch CPU 0 map, it's allocated at aboot and kept @@ -472,8 +456,6 @@ static int mmu_ctx_cpu_dead(unsigned int cpu) return 0; } -#endif /* CONFIG_SMP */ - /* * Initialize the context management stuff. */ @@ -497,16 +479,16 @@ void __init mmu_context_init(void) if (!context_mm) panic("%s: Failed to allocate %zu bytes\n", __func__, sizeof(void *) * (LAST_CONTEXT + 1)); -#ifdef CONFIG_SMP - stale_map[boot_cpuid] = memblock_alloc(CTX_MAP_SIZE, SMP_CACHE_BYTES); - if (!stale_map[boot_cpuid]) - panic("%s: Failed to allocate %zu bytes\n", __func__, - CTX_MAP_SIZE); - - cpuhp_setup_state_nocalls(CPUHP_POWERPC_MMU_CTX_PREPARE, - "powerpc/mmu/ctx:prepare", - mmu_ctx_cpu_prepare, mmu_ctx_cpu_dead); -#endif + if (IS_ENABLED(CONFIG_SMP)) { + stale_map[boot_cpuid] = memblock_alloc(CTX_MAP_SIZE, SMP_CACHE_BYTES); + if (!stale_map[boot_cpuid]) + panic("%s: Failed to allocate %zu bytes\n", __func__, + CTX_MAP_SIZE); + + cpuhp_setup_state_nocalls(CPUHP_POWERPC_MMU_CTX_PREPARE, + "powerpc/mmu/ctx:prepare", + mmu_ctx_cpu_prepare, mmu_ctx_cpu_dead); + } printk(KERN_INFO "MMU: Allocated %zu bytes of context maps for %d contexts\n", -- 2.25.0