powerpc/mm: Remove stale_map[] handling on non SMP processors

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 <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/mm/mmu_context_nohash.c b/arch/powerpc/mm/mmu_context_nohash.c
index 3cc59697d2533b69f87cff77c2f1fde030c3bf65..4d80239ef83c37a9c322794356bfbcc9f21db98d 100644 (file)
--- a/arch/powerpc/mm/mmu_context_nohash.c
+++ b/arch/powerpc/mm/mmu_context_nohash.c
@@ -84,7 +84,9 @@
 
 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);
 
@@ -165,7 +167,9 @@ 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++) {
@@ -183,7 +187,9 @@ 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) */
@@ -202,7 +208,9 @@ 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];
@@ -216,7 +224,9 @@ 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;
 }
@@ -255,7 +265,10 @@ 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 */
@@ -329,6 +342,7 @@ 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),
@@ -343,6 +357,7 @@ 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);
@@ -448,9 +463,7 @@ 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,