+ arch-kmap-remove-bug_on.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: arch/kmap: remove BUG_ON()
has been added to the -mm tree.  Its filename is
     arch-kmap-remove-bug_on.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/arch-kmap-remove-bug_on.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/arch-kmap-remove-bug_on.patch

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------------------------------------------------------
From: Ira Weiny <ira.weiny@intel.com>
Subject: arch/kmap: remove BUG_ON()

Patch series "Remove duplicated kmap code", v1.

The kmap infrastructure has been copied almost verbatim to every
architecture.  This series consolidates obvious duplicated code by
defining core functions which call into the architectures only when
needed.

Some of the k[un]map_atomic() implementations have some similarities but
the similarities were not sufficient to warrant further changes.

In addition we remove a duplicate implementation of kmap() in DRM.


This patch (of 10):

Replace the use of BUG_ON(in_interrupt()) in the kmap() and kunmap() in
favor of might_sleep().

Besides the benefits of might_sleep(), this normalizes the implementations
such that they can be made generic in subsequent patches.

Link: http://lkml.kernel.org/r/20200430203845.582900-1-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20200430203845.582900-2-ira.weiny@intel.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>,
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/arc/include/asm/highmem.h        |    2 +-
 arch/arc/mm/highmem.c                 |    2 +-
 arch/arm/mm/highmem.c                 |    2 +-
 arch/csky/mm/highmem.c                |    2 +-
 arch/microblaze/include/asm/highmem.h |    2 +-
 arch/mips/mm/highmem.c                |    2 +-
 arch/nds32/mm/highmem.c               |    2 +-
 arch/powerpc/include/asm/highmem.h    |    2 +-
 arch/sparc/include/asm/highmem.h      |    4 ++--
 arch/x86/mm/highmem_32.c              |    3 +--
 arch/xtensa/include/asm/highmem.h     |    4 ++--
 11 files changed, 13 insertions(+), 14 deletions(-)

--- a/arch/arc/include/asm/highmem.h~arch-kmap-remove-bug_on
+++ a/arch/arc/include/asm/highmem.h
@@ -45,7 +45,7 @@ static inline void flush_cache_kmaps(voi
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
--- a/arch/arc/mm/highmem.c~arch-kmap-remove-bug_on
+++ a/arch/arc/mm/highmem.c
@@ -51,7 +51,7 @@ static pte_t * fixmap_page_table;
 
 void *kmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return page_address(page);
 
--- a/arch/arm/mm/highmem.c~arch-kmap-remove-bug_on
+++ a/arch/arm/mm/highmem.c
@@ -42,7 +42,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
--- a/arch/csky/mm/highmem.c~arch-kmap-remove-bug_on
+++ a/arch/csky/mm/highmem.c
@@ -29,7 +29,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
--- a/arch/microblaze/include/asm/highmem.h~arch-kmap-remove-bug_on
+++ a/arch/microblaze/include/asm/highmem.h
@@ -66,7 +66,7 @@ static inline void *kmap(struct page *pa
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
--- a/arch/mips/mm/highmem.c~arch-kmap-remove-bug_on
+++ a/arch/mips/mm/highmem.c
@@ -28,7 +28,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
--- a/arch/nds32/mm/highmem.c~arch-kmap-remove-bug_on
+++ a/arch/nds32/mm/highmem.c
@@ -24,7 +24,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
--- a/arch/powerpc/include/asm/highmem.h~arch-kmap-remove-bug_on
+++ a/arch/powerpc/include/asm/highmem.h
@@ -74,7 +74,7 @@ static inline void *kmap(struct page *pa
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
--- a/arch/sparc/include/asm/highmem.h~arch-kmap-remove-bug_on
+++ a/arch/sparc/include/asm/highmem.h
@@ -55,7 +55,7 @@ void kunmap_high(struct page *page);
 
 static inline void *kmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return page_address(page);
 	return kmap_high(page);
@@ -63,7 +63,7 @@ static inline void *kmap(struct page *pa
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
--- a/arch/x86/mm/highmem_32.c~arch-kmap-remove-bug_on
+++ a/arch/x86/mm/highmem_32.c
@@ -15,8 +15,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	if (in_interrupt())
-		BUG();
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
--- a/arch/xtensa/include/asm/highmem.h~arch-kmap-remove-bug_on
+++ a/arch/xtensa/include/asm/highmem.h
@@ -73,7 +73,7 @@ static inline void *kmap(struct page *pa
 	 */
 	BUILD_BUG_ON(PKMAP_BASE <
 		     TLBTEMP_BASE_1 + TLBTEMP_SIZE);
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return page_address(page);
 	return kmap_high(page);
@@ -81,7 +81,7 @@ static inline void *kmap(struct page *pa
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
_

Patches currently in -mm which might be from ira.weiny@intel.com are

arch-kmap-remove-bug_on.patch
arch-xtensa-move-kmap-build-bug-out-of-the-way.patch
arch-kmap-remove-redundant-arch-specific-kmaps.patch
arch-kunmap-remove-duplicate-kunmap-implementations.patch
arch-kmap_atomic-consolidate-duplicate-code.patch
arch-kunmap_atomic-consolidate-duplicate-code.patch
arch-kmap-ensure-kmap_prot-visibility.patch
arch-kmap-dont-hard-code-kmap_prot-values.patch
arch-kmap-define-kmap_atomic_prot-for-all-archs.patch
drm-remove-drm-specific-kmap_atomic-code.patch