[PATCH 4/4] powerpc/mm: Remove stale_map[] handling on non SMP processors
From: Christophe Leroy <hidden>
Date: 2018-03-21 14:08:08
Also in:
lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
stale_map[] bits are only set in steal_context_smp() so on UP processors this map is useless. Only manage it for SMP processors. Signed-off-by: Christophe Leroy <redacted> --- arch/powerpc/mm/mmu_context_nohash.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/mm/mmu_context_nohash.c b/arch/powerpc/mm/mmu_context_nohash.c
index 625c17049483..3f13f07f64dd 100644
--- a/arch/powerpc/mm/mmu_context_nohash.c
+++ b/arch/powerpc/mm/mmu_context_nohash.c@@ -88,7 +88,9 @@ 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);
@@ -169,7 +171,9 @@ static unsigned int steal_context_smp(unsigned int id) 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++) {
@@ -187,7 +191,9 @@ static unsigned int steal_all_contexts(void) mm->context.active = 0; #endif } +#ifdef CONFIG_SMP __clear_bit(id, stale_map[cpu]); +#endif } /* Flush the TLB for all contexts (not to be used on SMP) */
@@ -206,7 +212,9 @@ 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];
@@ -220,7 +228,9 @@ 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 return id; }
@@ -259,7 +269,10 @@ static void context_check_map(void) { } void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) { - unsigned int i, id, cpu = smp_processor_id(); + unsigned int id; +#ifdef CONFIG_SMP + unsigned int i, cpu = smp_processor_id(); +#endif unsigned long *map; /* No lockless fast path .. yet */
@@ -333,6 +346,7 @@ 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])) { pr_hardcont(" | stale flush %d [%d..%d]", id, cpu_first_thread_sibling(cpu),
@@ -347,6 +361,7 @@ 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);
@@ -452,9 +467,7 @@ void __init mmu_context_init(void) */ context_map = memblock_virt_alloc(CTX_MAP_SIZE, 0); context_mm = memblock_virt_alloc(sizeof(void *) * (LAST_CONTEXT + 1), 0); -#ifndef CONFIG_SMP - stale_map[0] = memblock_virt_alloc(CTX_MAP_SIZE, 0); -#else +#ifdef CONFIG_SMP stale_map[boot_cpuid] = memblock_virt_alloc(CTX_MAP_SIZE, 0); cpuhp_setup_state_nocalls(CPUHP_POWERPC_MMU_CTX_PREPARE,
--
2.13.3