[PATCH 4/5] arch/kmap_atomic: Consolidate duplicate code

From: ira . weiny
Date: Sun Apr 26 2020 - 01:54:33 EST


From: Ira Weiny <ira.weiny@xxxxxxxxx>

Every arch has the same check for a not HIGHMEM page. Define
kmap_atomic_fast() to quickly return already mapped pages and reduce the
code duplication by lifting this check to the core.

Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
---
arch/arc/mm/highmem.c | 7 +++----
arch/arm/mm/highmem.c | 8 +++-----
arch/csky/mm/highmem.c | 7 +++----
arch/microblaze/mm/highmem.c | 8 +++-----
arch/mips/mm/highmem.c | 7 +++----
arch/nds32/mm/highmem.c | 7 +++----
arch/powerpc/mm/highmem.c | 7 +++----
arch/sparc/mm/highmem.c | 7 +++----
arch/x86/mm/highmem_32.c | 8 +++-----
arch/xtensa/mm/highmem.c | 7 +++----
include/linux/highmem.h | 9 +++++++++
11 files changed, 39 insertions(+), 43 deletions(-)

diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
index 4db13a6b9f3b..1cae4b911a33 100644
--- a/arch/arc/mm/highmem.c
+++ b/arch/arc/mm/highmem.c
@@ -53,11 +53,10 @@ void *kmap_atomic(struct page *page)
{
int idx, cpu_idx;
unsigned long vaddr;
+ void *addr = kmap_atomic_fast(page);

- preempt_disable();
- pagefault_disable();
- if (!PageHighMem(page))
- return page_address(page);
+ if (addr)
+ return addr;

cpu_idx = kmap_atomic_idx_push();
idx = cpu_idx + KM_TYPE_NR * smp_processor_id();
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index c700b32350ee..4a629f616a6a 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -35,13 +35,11 @@ void *kmap_atomic(struct page *page)
{
unsigned int idx;
unsigned long vaddr;
- void *kmap;
+ void *kmap = kmap_atomic_fast(page);
int type;

- preempt_disable();
- pagefault_disable();
- if (!PageHighMem(page))
- return page_address(page);
+ if (kmap)
+ return kmap;

#ifdef CONFIG_DEBUG_HIGHMEM
/*
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index 69b1931986ae..1191f57f53ae 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -25,12 +25,11 @@ EXPORT_SYMBOL(kmap);
void *kmap_atomic(struct page *page)
{
unsigned long vaddr;
+ void *addr = kmap_atomic_fast(page);
int idx, type;

- preempt_disable();
- pagefault_disable();
- if (!PageHighMem(page))
- return page_address(page);
+ if (addr)
+ return addr;

type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
diff --git a/arch/microblaze/mm/highmem.c b/arch/microblaze/mm/highmem.c
index d7569f77fa15..99fdf826edc2 100644
--- a/arch/microblaze/mm/highmem.c
+++ b/arch/microblaze/mm/highmem.c
@@ -36,13 +36,11 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{

unsigned long vaddr;
+ void *addr = kmap_atomic_fast(page);
int idx, type;

- preempt_disable();
- pagefault_disable();
- if (!PageHighMem(page))
- return page_address(page);
-
+ if (addr)
+ return addr;

type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index c3c9fe962f0f..ba03ca75d4a1 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -33,12 +33,11 @@ EXPORT_SYMBOL(kmap);
void *kmap_atomic(struct page *page)
{
unsigned long vaddr;
+ void *addr = kmap_atomic_fast(page);
int idx, type;

- preempt_disable();
- pagefault_disable();
- if (!PageHighMem(page))
- return page_address(page);
+ if (addr)
+ return addr;

type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
index f9348bec0ecb..4aabde586489 100644
--- a/arch/nds32/mm/highmem.c
+++ b/arch/nds32/mm/highmem.c
@@ -14,13 +14,12 @@ void *kmap_atomic(struct page *page)
{
unsigned int idx;
unsigned long vaddr, pte;
+ void *addr = kmap_atomic_fast(page);
int type;
pte_t *ptep;

- preempt_disable();
- pagefault_disable();
- if (!PageHighMem(page))
- return page_address(page);
+ if (addr)
+ return addr;

type = kmap_atomic_idx_push();

diff --git a/arch/powerpc/mm/highmem.c b/arch/powerpc/mm/highmem.c
index 320c1672b2ae..cdf5b716801a 100644
--- a/arch/powerpc/mm/highmem.c
+++ b/arch/powerpc/mm/highmem.c
@@ -33,12 +33,11 @@
void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
unsigned long vaddr;
+ void *addr = kmap_atomic_fast(page);
int idx, type;

- preempt_disable();
- pagefault_disable();
- if (!PageHighMem(page))
- return page_address(page);
+ if (addr)
+ return addr;

type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
diff --git a/arch/sparc/mm/highmem.c b/arch/sparc/mm/highmem.c
index d4a80adea7e5..178641805567 100644
--- a/arch/sparc/mm/highmem.c
+++ b/arch/sparc/mm/highmem.c
@@ -56,12 +56,11 @@ void __init kmap_init(void)
void *kmap_atomic(struct page *page)
{
unsigned long vaddr;
+ void *addr = kmap_atomic_fast(page);
long idx, type;

- preempt_disable();
- pagefault_disable();
- if (!PageHighMem(page))
- return page_address(page);
+ if (addr)
+ return addr;

type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index c4ebfd0ae401..34770499b0ff 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -15,13 +15,11 @@
void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
unsigned long vaddr;
+ void *addr = kmap_atomic_fast(page);
int idx, type;

- preempt_disable();
- pagefault_disable();
-
- if (!PageHighMem(page))
- return page_address(page);
+ if (addr)
+ return addr;

type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c
index 184ceadccc1a..38c14e0b578c 100644
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -41,11 +41,10 @@ void *kmap_atomic(struct page *page)
{
enum fixed_addresses idx;
unsigned long vaddr;
+ void *addr = kmap_atomic_fast(page);

- preempt_disable();
- pagefault_disable();
- if (!PageHighMem(page))
- return page_address(page);
+ if (addr)
+ return addr;

idx = kmap_idx(kmap_atomic_idx_push(),
DCACHE_ALIAS(page_to_phys(page)));
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 1a3b7690c78c..eee53e151900 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -60,6 +60,15 @@ static inline void kunmap(struct page *page)
kunmap_high(page);
}

+static inline void *kmap_atomic_fast(struct page *page)
+{
+ preempt_disable();
+ pagefault_disable();
+ if (!PageHighMem(page))
+ return page_address(page);
+ return NULL;
+}
+
/* declarations for linux/mm/highmem.c */
unsigned int nr_free_highpages(void);
extern atomic_long_t _totalhigh_pages;
--
2.25.1