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>
This commit is contained in:
David Hildenbrand 2015-05-11 17:52:09 +02:00 committed by Ingo Molnar
parent b3c395ef55
commit 2cb7c9cb42
15 changed files with 38 additions and 7 deletions

View File

@ -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);

View File

@ -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);

View File

@ -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();

View File

@ -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);

View File

@ -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();

View File

@ -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__ */

View File

@ -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)

View File

@ -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);

View File

@ -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);

View File

@ -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);

View File

@ -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);

View File

@ -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);

View File

@ -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);

View File

@ -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))

View File

@ -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 */