From 14b19ee94fa00ff749b2fa8a2131c14ccfdd3d09 Mon Sep 17 00:00:00 2001
From: Matthew Wilcox <willy@infradead.org>
Date: Mon, 18 Jun 2018 08:26:32 -0400
Subject: [PATCH] ppc: Convert mmu context allocation to new IDA API
References: bsc#1139619 LTC#178538
Patch-mainline: v4.19-rc1
Git-commit: b3fa64170e21393b5790be89ab16cdfe1f5bddbc
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 <willy@infradead.org>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
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 c2a8f15a7972..d77bd6ce33da 100644
--- a/arch/powerpc/mm/mmu_context_book3s64.c
+++ b/arch/powerpc/mm/mmu_context_book3s64.c
@@ -26,48 +26,16 @@
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
-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);
}
@@ -211,9 +179,7 @@ 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);
@@ -221,13 +187,11 @@ 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);
}
#ifdef CONFIG_PPC_64K_PAGES
--
2.22.0