lkml.org 
[lkml]   [2018]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4/4] powerpc/mm: Remove stale_map[] handling on non SMP processors
    Date
    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>
    ---
    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
    \
     
     \ /
      Last update: 2018-03-21 15:08    [W:5.379 / U:0.128 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site