arch/kunmap: remove duplicate kunmap implementations

All architectures do exactly the same thing for kunmap(); remove all the
duplicate definitions and lift the call to the core.

This also has the benefit of changing kmap_unmap() on a number of
architectures to be an inline call rather than an actual function.

[akpm@linux-foundation.org: fix CONFIG_HIGHMEM=n build on various architectures]
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian König <christian.koenig@amd.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Helge Deller <deller@gmx.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200507150004.1423069-5-ira.weiny@intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/arc/include/asm/highmem.h

@@ -32,7 +32,6 @@
 
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
-extern void kunmap_high(struct page *page);
 
 extern void kmap_init(void);
 
@@ -41,15 +40,6 @@ static inline void flush_cache_kmaps(void)
 	flush_cache_all();
 }
 
-static inline void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-
-
 #endif
 
 #endif

arch/arm/include/asm/highmem.h

@@ -20,8 +20,6 @@
 
 extern pte_t *pkmap_page_table;
 
-extern void kunmap_high(struct page *page);
-
 /*
  * The reason for kmap_high_get() is to ensure that the currently kmap'd
  * page usage count does not decrease to zero while we're using its
@@ -62,7 +60,6 @@ static inline void *kmap_high_get(struct page *page)
  * when CONFIG_HIGHMEM is not set.
  */
 #ifdef CONFIG_HIGHMEM
-extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);

arch/arm/mm/highmem.c

@@ -31,15 +31,6 @@ static inline pte_t get_fixmap_pte(unsigned long vaddr)
 	return *ptep;
 }
 
-void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-EXPORT_SYMBOL(kunmap);
-
 void *kmap_atomic(struct page *page)
 {
 	unsigned int idx;

arch/csky/include/asm/highmem.h

@@ -30,11 +30,8 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void kunmap_high(struct page *page);
-
 #define ARCH_HAS_KMAP_FLUSH_TLB
 extern void kmap_flush_tlb(unsigned long addr);
-extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);

arch/csky/mm/highmem.c

@@ -21,15 +21,6 @@ EXPORT_SYMBOL(kmap_flush_tlb);
 
 EXPORT_SYMBOL(kmap);
 
-void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-EXPORT_SYMBOL(kunmap);
-
 void *kmap_atomic(struct page *page)
 {
 	unsigned long vaddr;

arch/microblaze/include/asm/highmem.h

@@ -51,18 +51,9 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void kunmap_high(struct page *page);
 extern void *kmap_atomic_prot(struct page *page, pgprot_t prot);
 extern void __kunmap_atomic(void *kvaddr);
 
-static inline void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-
 static inline void *kmap_atomic(struct page *page)
 {
 	return kmap_atomic_prot(page, kmap_prot);

arch/mips/include/asm/highmem.h

@@ -46,11 +46,8 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)	((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)	(PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void kunmap_high(struct page *page);
-
 #define ARCH_HAS_KMAP_FLUSH_TLB
 extern void kmap_flush_tlb(unsigned long addr);
-extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);

arch/mips/mm/highmem.c

@@ -18,15 +18,6 @@ void kmap_flush_tlb(unsigned long addr)
 }
 EXPORT_SYMBOL(kmap_flush_tlb);
 
-void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-EXPORT_SYMBOL(kunmap);
-
 /*
  * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
  * no global lock is needed and because the kmap code must perform a global TLB

arch/nds32/include/asm/highmem.h

@@ -44,16 +44,13 @@ extern unsigned long highstart_pfn, highend_pfn;
 
 extern pte_t *pkmap_page_table;
 
-extern void kunmap_high(struct page *page);
-
 extern void kmap_init(void);
 
 /*
  * The following functions are already defined by <linux/highmem.h>
  * when CONFIG_HIGHMEM is not set.
  */
 #ifdef CONFIG_HIGHMEM
-extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);

arch/nds32/mm/highmem.c

@@ -10,16 +10,6 @@
 #include <asm/fixmap.h>
 #include <asm/tlbflush.h>
 
-void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-
-EXPORT_SYMBOL(kunmap);
-
 void *kmap_atomic(struct page *page)
 {
 	unsigned int idx;

arch/powerpc/include/asm/highmem.h

@@ -59,18 +59,9 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void kunmap_high(struct page *page);
 extern void *kmap_atomic_prot(struct page *page, pgprot_t prot);
 extern void __kunmap_atomic(void *kvaddr);
 
-static inline void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-
 static inline void *kmap_atomic(struct page *page)
 {
 	return kmap_atomic_prot(page, kmap_prot);

arch/sparc/include/asm/highmem.h

@@ -50,16 +50,6 @@ void kmap_init(void) __init;
 
 #define PKMAP_END (PKMAP_ADDR(LAST_PKMAP))
 
-void kunmap_high(struct page *page);
-
-static inline void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-
 void *kmap_atomic(struct page *page);
 void __kunmap_atomic(void *kvaddr);
 

arch/x86/include/asm/highmem.h

@@ -58,10 +58,6 @@ extern unsigned long highstart_pfn, highend_pfn;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void kunmap_high(struct page *page);
-
-void kunmap(struct page *page);
-
 void *kmap_atomic_prot(struct page *page, pgprot_t prot);
 void *kmap_atomic(struct page *page);
 void __kunmap_atomic(void *kvaddr);

arch/x86/mm/highmem_32.c

@@ -4,15 +4,6 @@
 #include <linux/swap.h> /* for totalram_pages */
 #include <linux/memblock.h>
 
-void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-EXPORT_SYMBOL(kunmap);
-
 /*
  * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
  * no global lock is needed and because the kmap code must perform a global TLB

arch/xtensa/include/asm/highmem.h

@@ -63,16 +63,6 @@ static inline wait_queue_head_t *get_pkmap_wait_queue_head(unsigned int color)
 
 extern pte_t *pkmap_page_table;
 
-void kunmap_high(struct page *page);
-
-static inline void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-
 static inline void flush_cache_kmaps(void)
 {
 	flush_cache_all();

include/linux/highmem.h

@@ -52,6 +52,16 @@ static inline void *kmap(struct page *page)
 	return addr;
 }
 
+void kunmap_high(struct page *page);
+
+static inline void kunmap(struct page *page)
+{
+	might_sleep();
+	if (!PageHighMem(page))
+		return;
+	kunmap_high(page);
+}
+
 /* declarations for linux/mm/highmem.c */
 unsigned int nr_free_highpages(void);
 extern atomic_long_t _totalhigh_pages;
@@ -102,6 +112,10 @@ static inline void *kmap(struct page *page)
 	return page_address(page);
 }
 
+static inline void kunmap_high(struct page *page)
+{
+}
+
 static inline void kunmap(struct page *page)
 {
 }