diff mbox series

[V3,13/15] parisc/kmap: Remove duplicate kmap code

Message ID 20200507150004.1423069-14-ira.weiny@intel.com
State New
Headers show
Series Remove duplicated kmap code | expand

Commit Message

Ira Weiny May 7, 2020, 3 p.m. UTC 
From: Ira Weiny <ira.weiny@intel.com>

parisc reimplements the kmap calls except to flush it's dcache.  This is
arguably an abuse of kmap but regardless it is messy and confusing.

Remove the duplicate code and have parisc define
ARCH_HAS_FLUSH_ON_KUNMAP for a kunmap_flush_on_unmap() architecture
specific call to flush the cache.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Changes from V2:
	New Patch for this series
---
 arch/parisc/include/asm/cacheflush.h | 28 ++--------------------------
 include/linux/highmem.h              | 10 +++++++---
 2 files changed, 9 insertions(+), 29 deletions(-)

Comments

Andrew Morton May 7, 2020, 8:52 p.m. UTC | #1 
On Thu,  7 May 2020 08:00:01 -0700 ira.weiny@intel.com wrote:

> parisc reimplements the kmap calls except to flush it's dcache.  This is
> arguably an abuse of kmap but regardless it is messy and confusing.
> 
> Remove the duplicate code and have parisc define
> ARCH_HAS_FLUSH_ON_KUNMAP for a kunmap_flush_on_unmap() architecture
> specific call to flush the cache.

checkpatch says:

ERROR: #define of 'ARCH_HAS_FLUSH_ON_KUNMAP' is wrong - use Kconfig variables or standard guards instead
#69: FILE: arch/parisc/include/asm/cacheflush.h:103:
+#define ARCH_HAS_FLUSH_ON_KUNMAP

which is fair enough, I guess.  More conventional would be

arch/parisc/include/asm/cacheflush.h:

static inline void kunmap_flush_on_unmap(void *addr)
{
	...
}
#define kunmap_flush_on_unmap kunmap_flush_on_unmap


include/linux/highmem.h:

#ifndef kunmap_flush_on_unmap
static inline void kunmap_flush_on_unmap(void *addr)
{
}
#define kunmap_flush_on_unmap kunmap_flush_on_unmap
#endif


static inline void kunmap_atomic_high(void *addr)
{
	/* Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
	 * handles re-enabling faults + preemption */
	kunmap_flush_on_unmap(addr);
}


but I don't really think it's worth bothering changing it.	

(Ditto patch 3/15)
Ira Weiny May 7, 2020, 10:50 p.m. UTC | #2 
On Thu, May 07, 2020 at 01:52:58PM -0700, Andrew Morton wrote:
> On Thu,  7 May 2020 08:00:01 -0700 ira.weiny@intel.com wrote:
> 
> > parisc reimplements the kmap calls except to flush it's dcache.  This is
> > arguably an abuse of kmap but regardless it is messy and confusing.
> > 
> > Remove the duplicate code and have parisc define
> > ARCH_HAS_FLUSH_ON_KUNMAP for a kunmap_flush_on_unmap() architecture
> > specific call to flush the cache.
> 
> checkpatch says:
> 
> ERROR: #define of 'ARCH_HAS_FLUSH_ON_KUNMAP' is wrong - use Kconfig variables or standard guards instead
> #69: FILE: arch/parisc/include/asm/cacheflush.h:103:
> +#define ARCH_HAS_FLUSH_ON_KUNMAP
> 
> which is fair enough, I guess.  More conventional would be
> 
> arch/parisc/include/asm/cacheflush.h:
> 
> static inline void kunmap_flush_on_unmap(void *addr)
> {
> 	...
> }
> #define kunmap_flush_on_unmap kunmap_flush_on_unmap
> 
> 
> include/linux/highmem.h:
> 
> #ifndef kunmap_flush_on_unmap
> static inline void kunmap_flush_on_unmap(void *addr)
> {
> }
> #define kunmap_flush_on_unmap kunmap_flush_on_unmap
> #endif
> 
> 
> static inline void kunmap_atomic_high(void *addr)
> {
> 	/* Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
> 	 * handles re-enabling faults + preemption */
> 	kunmap_flush_on_unmap(addr);
> }
> 
> 
> but I don't really think it's worth bothering changing it.	
> 
> (Ditto patch 3/15)

Yes I was following the pattern already there.

I'll fix up the last patch now.
Ira
diff mbox series

Patch

diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h
index 119c9a7681bc..99663fc1f997 100644
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/arch/parisc/include/asm/cacheflush.h
@@ -100,35 +100,11 @@  flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vma
 	}
 }
 
-#include <asm/kmap_types.h>
-
-#define ARCH_HAS_KMAP
-
-static inline void *kmap(struct page *page)
-{
-	might_sleep();
-	return page_address(page);
-}
-
-static inline void kunmap(struct page *page)
-{
-	flush_kernel_dcache_page_addr(page_address(page));
-}
-
-static inline void *kmap_atomic(struct page *page)
-{
-	preempt_disable();
-	pagefault_disable();
-	return page_address(page);
-}
-
-static inline void kunmap_atomic_high(void *addr)
+#define ARCH_HAS_FLUSH_ON_KUNMAP
+static inline void kunmap_flush_on_unmap(void *addr)
 {
 	flush_kernel_dcache_page_addr(addr);
 }
 
-#define kmap_atomic_prot(page, prot)	kmap_atomic(page)
-#define kmap_atomic_pfn(pfn)	kmap_atomic(pfn_to_page(pfn))
-
 #endif /* _PARISC_CACHEFLUSH_H */
 
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 89838306f50d..cc0c3904e501 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -129,7 +129,6 @@  static inline struct page *kmap_to_page(void *addr)
 
 static inline unsigned long totalhigh_pages(void) { return 0UL; }
 
-#ifndef ARCH_HAS_KMAP
 static inline void *kmap(struct page *page)
 {
 	might_sleep();
@@ -138,6 +137,9 @@  static inline void *kmap(struct page *page)
 
 static inline void kunmap(struct page *page)
 {
+#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
+	kunmap_flush_on_unmap(page_address(page));
+#endif
 }
 
 static inline void *kmap_atomic(struct page *page)
@@ -150,14 +152,16 @@  static inline void *kmap_atomic(struct page *page)
 
 static inline void kunmap_atomic_high(void *addr)
 {
-	/* Nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
+	/* Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
 	 * handles re-enabling faults + preemption */
+#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
+	kunmap_flush_on_unmap(addr);
+#endif
 }
 
 #define kmap_atomic_pfn(pfn)	kmap_atomic(pfn_to_page(pfn))
 
 #define kmap_flush_unused()	do {} while(0)
-#endif
 
 #endif /* CONFIG_HIGHMEM */