original_kernel/arch/frv/mm/highmem.c

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/* highmem.c: arch-specific highmem stuff
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/highmem.h>
#include <linux/module.h>
void *kmap(struct page *page)
{
might_sleep();
if (!PageHighMem(page))
return page_address(page);
return kmap_high(page);
}
EXPORT_SYMBOL(kmap);
void kunmap(struct page *page)
{
if (in_interrupt())
BUG();
if (!PageHighMem(page))
return;
kunmap_high(page);
}
EXPORT_SYMBOL(kunmap);
struct page *kmap_atomic_to_page(void *ptr)
{
return virt_to_page(ptr);
}
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>
2010-10-27 05:21:51 +08:00
void *__kmap_atomic(struct page *page)
{
unsigned long paddr;
int type;
pagefault_disable();
type = kmap_atomic_idx_push();
paddr = page_to_phys(page);
switch (type) {
/*
* The first 4 primary maps are reserved for architecture code
*/
case 0: return __kmap_atomic_primary(4, paddr, 6);
case 1: return __kmap_atomic_primary(5, paddr, 7);
case 2: return __kmap_atomic_primary(6, paddr, 8);
case 3: return __kmap_atomic_primary(7, paddr, 9);
case 4: return __kmap_atomic_primary(8, paddr, 10);
case 5 ... 5 + NR_TLB_LINES - 1:
return __kmap_atomic_secondary(type - 5, paddr);
default:
BUG();
return NULL;
}
}
EXPORT_SYMBOL(__kmap_atomic);
void __kunmap_atomic(void *kvaddr)
{
int type = kmap_atomic_idx_pop();
switch (type) {
case 0: __kunmap_atomic_primary(4, 6); break;
case 1: __kunmap_atomic_primary(5, 7); break;
case 2: __kunmap_atomic_primary(6, 8); break;
case 3: __kunmap_atomic_primary(7, 9); break;
case 4: __kunmap_atomic_primary(8, 10); break;
case 5 ... 5 + NR_TLB_LINES - 1:
__kunmap_atomic_secondary(type - 5, kvaddr);
break;
default:
BUG();
}
pagefault_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);