mm: stack based kmap_atomic()
Keep the current interface but ignore the KM_type and use a stack based
approach.
The advantage is that we get rid of crappy code like:
#define __KM_PTE \
(in_nmi() ? KM_NMI_PTE : \
in_irq() ? KM_IRQ_PTE : \
KM_PTE0)
and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.
The downside is that FRV kmap_atomic() gets more expensive.
For now we use a CPP trick suggested by Andrew:
#define kmap_atomic(page, args...) __kmap_atomic(page)
to avoid having to touch all kmap_atomic() users in a single patch.
[ not compiled on:
- mn10300: the arch doesn't actually build with highmem to begin with ]
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/frv/include/asm/highmem.h b/arch/frv/include/asm/highmem.h
index cb4c317..a8d6565 100644
--- a/arch/frv/include/asm/highmem.h
+++ b/arch/frv/include/asm/highmem.h
@@ -112,12 +112,11 @@
(void *) damlr; \
})
-static inline void *kmap_atomic(struct page *page, enum km_type type)
+static inline void *kmap_atomic_primary(struct page *page, enum km_type type)
{
unsigned long paddr;
pagefault_disable();
- debug_kmap_atomic(type);
paddr = page_to_phys(page);
switch (type) {
@@ -125,14 +124,6 @@
case 1: return __kmap_atomic_primary(1, paddr, 3);
case 2: return __kmap_atomic_primary(2, paddr, 4);
case 3: return __kmap_atomic_primary(3, paddr, 5);
- case 4: return __kmap_atomic_primary(4, paddr, 6);
- case 5: return __kmap_atomic_primary(5, paddr, 7);
- case 6: return __kmap_atomic_primary(6, paddr, 8);
- case 7: return __kmap_atomic_primary(7, paddr, 9);
- case 8: return __kmap_atomic_primary(8, paddr, 10);
-
- case 9 ... 9 + NR_TLB_LINES - 1:
- return __kmap_atomic_secondary(type - 9, paddr);
default:
BUG();
@@ -152,22 +143,13 @@
asm volatile("tlbpr %0,gr0,#4,#1" : : "r"(vaddr) : "memory"); \
} while(0)
-static inline void kunmap_atomic_notypecheck(void *kvaddr, enum km_type type)
+static inline void kunmap_atomic_primary(void *kvaddr, enum km_type type)
{
switch (type) {
case 0: __kunmap_atomic_primary(0, 2); break;
case 1: __kunmap_atomic_primary(1, 3); break;
case 2: __kunmap_atomic_primary(2, 4); break;
case 3: __kunmap_atomic_primary(3, 5); break;
- case 4: __kunmap_atomic_primary(4, 6); break;
- case 5: __kunmap_atomic_primary(5, 7); break;
- case 6: __kunmap_atomic_primary(6, 8); break;
- case 7: __kunmap_atomic_primary(7, 9); break;
- case 8: __kunmap_atomic_primary(8, 10); break;
-
- case 9 ... 9 + NR_TLB_LINES - 1:
- __kunmap_atomic_secondary(type - 9, kvaddr);
- break;
default:
BUG();
@@ -175,6 +157,9 @@
pagefault_enable();
}
+void *__kmap_atomic(struct page *page);
+void __kunmap_atomic(void *kvaddr);
+
#endif /* !__ASSEMBLY__ */
#endif /* __KERNEL__ */