From b3fa64170e21393b5790be89ab16cdfe1f5bddbc Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Mon, 18 Jun 2018 08:26:32 -0400 Subject: [PATCH] ppc: Convert mmu context allocation to new IDA API ida_alloc_range is the perfect fit for this use case. Eliminates a custom spinlock, a call to ida_pre_get and a local check for the allocated ID exceeding a maximum. Signed-off-by: Matthew Wilcox Reviewed-by: Nicholas Piggin --- arch/powerpc/mm/mmu_context_book3s64.c | 44 +++----------------------- 1 file changed, 4 insertions(+), 40 deletions(-) diff --git a/arch/powerpc/mm/mmu_context_book3s64.c b/arch/powerpc/mm/mmu_context_book3s64.c index f3d4b4a0e561..5a0cf2cc8ba0 100644 --- a/arch/powerpc/mm/mmu_context_book3s64.c +++ b/arch/powerpc/mm/mmu_context_book3s64.c @@ -26,48 +26,16 @@ #include #include -static DEFINE_SPINLOCK(mmu_context_lock); static DEFINE_IDA(mmu_context_ida); static int alloc_context_id(int min_id, int max_id) { - int index, err; - -again: - if (!ida_pre_get(&mmu_context_ida, GFP_KERNEL)) - return -ENOMEM; - - spin_lock(&mmu_context_lock); - err = ida_get_new_above(&mmu_context_ida, min_id, &index); - spin_unlock(&mmu_context_lock); - - if (err == -EAGAIN) - goto again; - else if (err) - return err; - - if (index > max_id) { - spin_lock(&mmu_context_lock); - ida_remove(&mmu_context_ida, index); - spin_unlock(&mmu_context_lock); - return -ENOMEM; - } - - return index; + return ida_alloc_range(&mmu_context_ida, min_id, max_id, GFP_KERNEL); } void hash__reserve_context_id(int id) { - int rc, result = 0; - - do { - if (!ida_pre_get(&mmu_context_ida, GFP_KERNEL)) - break; - - spin_lock(&mmu_context_lock); - rc = ida_get_new_above(&mmu_context_ida, id, &result); - spin_unlock(&mmu_context_lock); - } while (rc == -EAGAIN); + int result = ida_alloc_range(&mmu_context_ida, id, id, GFP_KERNEL); WARN(result != id, "mmu: Failed to reserve context id %d (rc %d)\n", id, result); } @@ -172,9 +140,7 @@ int init_new_context(struct task_struct *tsk, struct mm_struct *mm) void __destroy_context(int context_id) { - spin_lock(&mmu_context_lock); - ida_remove(&mmu_context_ida, context_id); - spin_unlock(&mmu_context_lock); + ida_free(&mmu_context_ida, context_id); } EXPORT_SYMBOL_GPL(__destroy_context); @@ -182,13 +148,11 @@ static void destroy_contexts(mm_context_t *ctx) { int index, context_id; - spin_lock(&mmu_context_lock); for (index = 0; index < ARRAY_SIZE(ctx->extended_id); index++) { context_id = ctx->extended_id[index]; if (context_id) - ida_remove(&mmu_context_ida, context_id); + ida_free(&mmu_context_ida, context_id); } - spin_unlock(&mmu_context_lock); } static void pte_frag_destroy(void *pte_frag) -- 2.45.2