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From: tip-bot for David Hildenbrand <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: torvalds@linux-foundation.org, linux-kernel@vger.kernel.org,
	hpa@zytor.com, peterz@infradead.org, tglx@linutronix.de,
	mingo@kernel.org, dahi@linux.vnet.ibm.com
Subject: [tip:sched/core] sched/preempt, mm/kmap: Explicitly disable/ enable preemption in kmap_atomic_*
Date: Tue, 19 May 2015 00:19:11 -0700	[thread overview]
Message-ID: <tip-2cb7c9cb426660b5ed58b643d9e7dd5d50ba901f@git.kernel.org> (raw)
In-Reply-To: <1431359540-32227-5-git-send-email-dahi@linux.vnet.ibm.com>

Commit-ID:  2cb7c9cb426660b5ed58b643d9e7dd5d50ba901f
Gitweb:     http://git.kernel.org/tip/2cb7c9cb426660b5ed58b643d9e7dd5d50ba901f
Author:     David Hildenbrand <dahi@linux.vnet.ibm.com>
AuthorDate: Mon, 11 May 2015 17:52:09 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 19 May 2015 08:39:14 +0200

sched/preempt, mm/kmap: Explicitly disable/enable preemption in kmap_atomic_*

The existing code relies on pagefault_disable() implicitly disabling
preemption, so that no schedule will happen between kmap_atomic() and
kunmap_atomic().

Let's make this explicit, to prepare for pagefault_disable() not
touching preemption anymore.

Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bigeasy@linutronix.de
Cc: borntraeger@de.ibm.com
Cc: daniel.vetter@intel.com
Cc: heiko.carstens@de.ibm.com
Cc: herbert@gondor.apana.org.au
Cc: hocko@suse.cz
Cc: hughd@google.com
Cc: mst@redhat.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: schwidefsky@de.ibm.com
Cc: yang.shi@windriver.com
Link: http://lkml.kernel.org/r/1431359540-32227-5-git-send-email-dahi@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/arm/mm/highmem.c                | 3 +++
 arch/frv/mm/highmem.c                | 2 ++
 arch/metag/mm/highmem.c              | 4 +++-
 arch/microblaze/mm/highmem.c         | 4 +++-
 arch/mips/mm/highmem.c               | 5 ++++-
 arch/mn10300/include/asm/highmem.h   | 3 +++
 arch/parisc/include/asm/cacheflush.h | 2 ++
 arch/powerpc/mm/highmem.c            | 4 +++-
 arch/sparc/mm/highmem.c              | 4 +++-
 arch/tile/mm/highmem.c               | 3 ++-
 arch/x86/mm/highmem_32.c             | 3 ++-
 arch/x86/mm/iomap_32.c               | 2 ++
 arch/xtensa/mm/highmem.c             | 2 ++
 include/linux/highmem.h              | 2 ++
 include/linux/io-mapping.h           | 2 ++
 15 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index b98895d..ee8dfa7 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -59,6 +59,7 @@ void *kmap_atomic(struct page *page)
 	void *kmap;
 	int type;
 
+	preempt_disable();
 	pagefault_disable();
 	if (!PageHighMem(page))
 		return page_address(page);
@@ -121,6 +122,7 @@ void __kunmap_atomic(void *kvaddr)
 		kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
 	}
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
@@ -130,6 +132,7 @@ void *kmap_atomic_pfn(unsigned long pfn)
 	int idx, type;
 	struct page *page = pfn_to_page(pfn);
 
+	preempt_disable();
 	pagefault_disable();
 	if (!PageHighMem(page))
 		return page_address(page);
diff --git a/arch/frv/mm/highmem.c b/arch/frv/mm/highmem.c
index bed9a9b..785344b 100644
--- a/arch/frv/mm/highmem.c
+++ b/arch/frv/mm/highmem.c
@@ -42,6 +42,7 @@ void *kmap_atomic(struct page *page)
 	unsigned long paddr;
 	int type;
 
+	preempt_disable();
 	pagefault_disable();
 	type = kmap_atomic_idx_push();
 	paddr = page_to_phys(page);
@@ -85,5 +86,6 @@ void __kunmap_atomic(void *kvaddr)
 	}
 	kmap_atomic_idx_pop();
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
diff --git a/arch/metag/mm/highmem.c b/arch/metag/mm/highmem.c
index d71f621..807f1b1 100644
--- a/arch/metag/mm/highmem.c
+++ b/arch/metag/mm/highmem.c
@@ -43,7 +43,7 @@ void *kmap_atomic(struct page *page)
 	unsigned long vaddr;
 	int type;
 
-	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+	preempt_disable();
 	pagefault_disable();
 	if (!PageHighMem(page))
 		return page_address(page);
@@ -82,6 +82,7 @@ void __kunmap_atomic(void *kvaddr)
 	}
 
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
@@ -95,6 +96,7 @@ void *kmap_atomic_pfn(unsigned long pfn)
 	unsigned long vaddr;
 	int type;
 
+	preempt_disable();
 	pagefault_disable();
 
 	type = kmap_atomic_idx_push();
diff --git a/arch/microblaze/mm/highmem.c b/arch/microblaze/mm/highmem.c
index 5a92576..2fcc5a5 100644
--- a/arch/microblaze/mm/highmem.c
+++ b/arch/microblaze/mm/highmem.c
@@ -37,7 +37,7 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 	unsigned long vaddr;
 	int idx, type;
 
-	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+	preempt_disable();
 	pagefault_disable();
 	if (!PageHighMem(page))
 		return page_address(page);
@@ -63,6 +63,7 @@ void __kunmap_atomic(void *kvaddr)
 
 	if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
 		pagefault_enable();
+		preempt_enable();
 		return;
 	}
 
@@ -84,5 +85,6 @@ void __kunmap_atomic(void *kvaddr)
 #endif
 	kmap_atomic_idx_pop();
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index da815d2..11661cb 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -47,7 +47,7 @@ void *kmap_atomic(struct page *page)
 	unsigned long vaddr;
 	int idx, type;
 
-	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+	preempt_disable();
 	pagefault_disable();
 	if (!PageHighMem(page))
 		return page_address(page);
@@ -72,6 +72,7 @@ void __kunmap_atomic(void *kvaddr)
 
 	if (vaddr < FIXADDR_START) { // FIXME
 		pagefault_enable();
+		preempt_enable();
 		return;
 	}
 
@@ -92,6 +93,7 @@ void __kunmap_atomic(void *kvaddr)
 #endif
 	kmap_atomic_idx_pop();
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
@@ -104,6 +106,7 @@ void *kmap_atomic_pfn(unsigned long pfn)
 	unsigned long vaddr;
 	int idx, type;
 
+	preempt_disable();
 	pagefault_disable();
 
 	type = kmap_atomic_idx_push();
diff --git a/arch/mn10300/include/asm/highmem.h b/arch/mn10300/include/asm/highmem.h
index 2fbbe4d..1ddea5a 100644
--- a/arch/mn10300/include/asm/highmem.h
+++ b/arch/mn10300/include/asm/highmem.h
@@ -75,6 +75,7 @@ static inline void *kmap_atomic(struct page *page)
 	unsigned long vaddr;
 	int idx, type;
 
+	preempt_disable();
 	pagefault_disable();
 	if (page < highmem_start_page)
 		return page_address(page);
@@ -98,6 +99,7 @@ static inline void __kunmap_atomic(unsigned long vaddr)
 
 	if (vaddr < FIXADDR_START) { /* FIXME */
 		pagefault_enable();
+		preempt_enable();
 		return;
 	}
 
@@ -122,6 +124,7 @@ static inline void __kunmap_atomic(unsigned long vaddr)
 
 	kmap_atomic_idx_pop();
 	pagefault_enable();
+	preempt_enable();
 }
 #endif /* __KERNEL__ */
 
diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h
index de65f66..ec2df4b 100644
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/arch/parisc/include/asm/cacheflush.h
@@ -142,6 +142,7 @@ static inline void kunmap(struct page *page)
 
 static inline void *kmap_atomic(struct page *page)
 {
+	preempt_disable();
 	pagefault_disable();
 	return page_address(page);
 }
@@ -150,6 +151,7 @@ static inline void __kunmap_atomic(void *addr)
 {
 	flush_kernel_dcache_page_addr(addr);
 	pagefault_enable();
+	preempt_enable();
 }
 
 #define kmap_atomic_prot(page, prot)	kmap_atomic(page)
diff --git a/arch/powerpc/mm/highmem.c b/arch/powerpc/mm/highmem.c
index e7450bd..e292c8a 100644
--- a/arch/powerpc/mm/highmem.c
+++ b/arch/powerpc/mm/highmem.c
@@ -34,7 +34,7 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 	unsigned long vaddr;
 	int idx, type;
 
-	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+	preempt_disable();
 	pagefault_disable();
 	if (!PageHighMem(page))
 		return page_address(page);
@@ -59,6 +59,7 @@ void __kunmap_atomic(void *kvaddr)
 
 	if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
 		pagefault_enable();
+		preempt_enable();
 		return;
 	}
 
@@ -82,5 +83,6 @@ void __kunmap_atomic(void *kvaddr)
 
 	kmap_atomic_idx_pop();
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
diff --git a/arch/sparc/mm/highmem.c b/arch/sparc/mm/highmem.c
index 449f864..a454ec5 100644
--- a/arch/sparc/mm/highmem.c
+++ b/arch/sparc/mm/highmem.c
@@ -53,7 +53,7 @@ void *kmap_atomic(struct page *page)
 	unsigned long vaddr;
 	long idx, type;
 
-	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+	preempt_disable();
 	pagefault_disable();
 	if (!PageHighMem(page))
 		return page_address(page);
@@ -91,6 +91,7 @@ void __kunmap_atomic(void *kvaddr)
 
 	if (vaddr < FIXADDR_START) { // FIXME
 		pagefault_enable();
+		preempt_enable();
 		return;
 	}
 
@@ -126,5 +127,6 @@ void __kunmap_atomic(void *kvaddr)
 
 	kmap_atomic_idx_pop();
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
diff --git a/arch/tile/mm/highmem.c b/arch/tile/mm/highmem.c
index 6aa2f26..fcd5450 100644
--- a/arch/tile/mm/highmem.c
+++ b/arch/tile/mm/highmem.c
@@ -201,7 +201,7 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 	int idx, type;
 	pte_t *pte;
 
-	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+	preempt_disable();
 	pagefault_disable();
 
 	/* Avoid icache flushes by disallowing atomic executable mappings. */
@@ -259,6 +259,7 @@ void __kunmap_atomic(void *kvaddr)
 	}
 
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index 4500142..eecb207a 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -35,7 +35,7 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 	unsigned long vaddr;
 	int idx, type;
 
-	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+	preempt_disable();
 	pagefault_disable();
 
 	if (!PageHighMem(page))
@@ -100,6 +100,7 @@ void __kunmap_atomic(void *kvaddr)
 #endif
 
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c
index 9ca35fc..2b7ece0 100644
--- a/arch/x86/mm/iomap_32.c
+++ b/arch/x86/mm/iomap_32.c
@@ -59,6 +59,7 @@ void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
 	unsigned long vaddr;
 	int idx, type;
 
+	preempt_disable();
 	pagefault_disable();
 
 	type = kmap_atomic_idx_push();
@@ -117,5 +118,6 @@ iounmap_atomic(void __iomem *kvaddr)
 	}
 
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL_GPL(iounmap_atomic);
diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c
index 8cfb71e..184cead 100644
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -42,6 +42,7 @@ void *kmap_atomic(struct page *page)
 	enum fixed_addresses idx;
 	unsigned long vaddr;
 
+	preempt_disable();
 	pagefault_disable();
 	if (!PageHighMem(page))
 		return page_address(page);
@@ -79,6 +80,7 @@ void __kunmap_atomic(void *kvaddr)
 	}
 
 	pagefault_enable();
+	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 9286a46..6aefcd0 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -65,6 +65,7 @@ static inline void kunmap(struct page *page)
 
 static inline void *kmap_atomic(struct page *page)
 {
+	preempt_disable();
 	pagefault_disable();
 	return page_address(page);
 }
@@ -73,6 +74,7 @@ static inline void *kmap_atomic(struct page *page)
 static inline void __kunmap_atomic(void *addr)
 {
 	pagefault_enable();
+	preempt_enable();
 }
 
 #define kmap_atomic_pfn(pfn)	kmap_atomic(pfn_to_page(pfn))
diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h
index 657fab4..c27dde7 100644
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -141,6 +141,7 @@ static inline void __iomem *
 io_mapping_map_atomic_wc(struct io_mapping *mapping,
 			 unsigned long offset)
 {
+	preempt_disable();
 	pagefault_disable();
 	return ((char __force __iomem *) mapping) + offset;
 }
@@ -149,6 +150,7 @@ static inline void
 io_mapping_unmap_atomic(void __iomem *vaddr)
 {
 	pagefault_enable();
+	preempt_enable();
 }
 
 /* Non-atomic map/unmap */

  reply	other threads:[~2015-05-19  7:19 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-11 15:52 [PATCH v1 00/15] decouple pagefault_disable() from preempt_disable() David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 01/15] uaccess: count pagefault_disable() levels in pagefault_disabled David Hildenbrand
2015-05-19  7:18   ` [tip:sched/core] sched/preempt, mm/fault: Count pagefault_disable () " tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 02/15] mm, uaccess: trigger might_sleep() in might_fault() with disabled pagefaults David Hildenbrand
2015-05-19  7:18   ` [tip:sched/core] sched/preempt, mm/fault: Trigger " tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 03/15] uaccess: clarify that uaccess may only sleep if pagefaults are enabled David Hildenbrand
2015-05-19  7:18   ` [tip:sched/core] mm/uaccess, mm/fault: Clarify " tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 04/15] mm: explicitly disable/enable preemption in kmap_atomic_* David Hildenbrand
2015-05-19  7:19   ` tip-bot for David Hildenbrand [this message]
2015-05-11 15:52 ` [PATCH v1 05/15] mips: kmap_coherent relies on disabled preemption David Hildenbrand
2015-05-19  7:19   ` [tip:sched/core] sched/preempt, mm/kmap, MIPS: Disable preemption in kmap_coherent() explicitly tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 06/15] mm: use pagefault_disable() to check for disabled pagefaults in the handler David Hildenbrand
2015-05-19  7:19   ` [tip:sched/core] mm/fault, arch: Use " tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 07/15] drm/i915: use pagefault_disabled() to check for disabled pagefaults David Hildenbrand
2015-05-19  7:20   ` [tip:sched/core] mm/fault, drm/i915: Use " tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 08/15] futex: UP futex_atomic_op_inuser() relies on disabled preemption David Hildenbrand
2015-05-19  7:20   ` [tip:sched/core] sched/preempt, futex: Disable preemption in UP futex_atomic_op_inuser() explicitly tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 09/15] futex: UP futex_atomic_cmpxchg_inatomic() relies on disabled preemption David Hildenbrand
2015-05-19  7:20   ` [tip:sched/core] sched/preempt, futex: Disable preemption in UP futex_atomic_cmpxchg_inatomic() explicitly tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 10/15] arm/futex: UP futex_atomic_cmpxchg_inatomic() relies on disabled preemption David Hildenbrand
2015-05-19  7:21   ` [tip:sched/core] sched/preempt, arm/futex: Disable preemption in UP futex_atomic_cmpxchg_inatomic() explicitly tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 11/15] arm/futex: UP futex_atomic_op_inuser() relies on disabled preemption David Hildenbrand
2015-05-12 19:00   ` Sebastian Andrzej Siewior
2015-05-13  7:38     ` David Hildenbrand
2015-05-13  8:19       ` Sebastian Andrzej Siewior
2015-05-13  8:55         ` David Hildenbrand
2015-05-19  7:21   ` [tip:sched/core] sched/preempt, arm/futex: Disable preemption in UP futex_atomic_op_inuser() explicitly tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 12/15] futex: clarify that preemption doesn't have to be disabled David Hildenbrand
2015-05-19  7:21   ` [tip:sched/core] sched/preempt, futex: Update comments to " tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 13/15] powerpc: enable_kernel_altivec() requires disabled preemption David Hildenbrand
2015-05-19  7:22   ` [tip:sched/core] sched/preempt, powerpc: Disable preemption in enable_kernel_altivec() explicitly tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 14/15] mips: properly lock access to the fpu David Hildenbrand
2015-05-19  7:22   ` [tip:sched/core] sched/preempt, MIPS: Properly lock access to the FPU tip-bot for David Hildenbrand
2015-05-11 15:52 ` [PATCH v1 15/15] uaccess: decouple preemption from the pagefault logic David Hildenbrand
2015-05-19  7:22   ` [tip:sched/core] sched/preempt, mm/fault: Decouple preemption from the page fault logic tip-bot for David Hildenbrand
2015-05-15 14:23 ` [PATCH v1 00/15] decouple pagefault_disable() from preempt_disable() Thomas Gleixner
2015-05-18 12:46   ` David Hildenbrand
2015-05-18 13:04     ` Peter Zijlstra

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