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yaml
---
r: 154396
b: refs/heads/master
c: 850f6ac
h: refs/heads/master
v: v3
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Benjamin Herrenschmidt committed Jun 26, 2009
1 parent b7e439d commit ff86310
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Showing 4 changed files with 83 additions and 54 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 85355bb272db31a3f2dd99d547eef794805e1319
refs/heads/master: 850f6ac316cf84bba63fdb775c897834eccbfaa3
57 changes: 4 additions & 53 deletions trunk/arch/powerpc/include/asm/highmem.h
Original file line number Diff line number Diff line change
Expand Up @@ -22,9 +22,7 @@

#ifdef __KERNEL__

#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/highmem.h>
#include <asm/kmap_types.h>
#include <asm/tlbflush.h>
#include <asm/page.h>
Expand Down Expand Up @@ -62,6 +60,9 @@ extern pte_t *pkmap_page_table;

extern void *kmap_high(struct page *page);
extern void kunmap_high(struct page *page);
extern void *kmap_atomic_prot(struct page *page, enum km_type type,
pgprot_t prot);
extern void kunmap_atomic(void *kvaddr, enum km_type type);

static inline void *kmap(struct page *page)
{
Expand All @@ -79,62 +80,11 @@ static inline void kunmap(struct page *page)
kunmap_high(page);
}

/*
* The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
* gives a more generic (and caching) interface. But kmap_atomic can
* be used in IRQ contexts, so in some (very limited) cases we need
* it.
*/
static inline void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
{
unsigned int idx;
unsigned long vaddr;

/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);

debug_kmap_atomic(type);
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(*(kmap_pte-idx)));
#endif
__set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot), 1);
local_flush_tlb_page(NULL, vaddr);

return (void*) vaddr;
}

static inline void *kmap_atomic(struct page *page, enum km_type type)
{
return kmap_atomic_prot(page, type, kmap_prot);
}

static inline void kunmap_atomic(void *kvaddr, enum km_type type)
{
#ifdef CONFIG_DEBUG_HIGHMEM
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();

if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
pagefault_enable();
return;
}

BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));

/*
* force other mappings to Oops if they'll try to access
* this pte without first remap it
*/
pte_clear(&init_mm, vaddr, kmap_pte-idx);
local_flush_tlb_page(NULL, vaddr);
#endif
pagefault_enable();
}

static inline struct page *kmap_atomic_to_page(void *ptr)
{
unsigned long idx, vaddr = (unsigned long) ptr;
Expand All @@ -148,6 +98,7 @@ static inline struct page *kmap_atomic_to_page(void *ptr)
return pte_page(*pte);
}


#define flush_cache_kmaps() flush_cache_all()

#endif /* __KERNEL__ */
Expand Down
1 change: 1 addition & 0 deletions trunk/arch/powerpc/mm/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -30,3 +30,4 @@ obj-$(CONFIG_PPC_MM_SLICES) += slice.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_PPC_SUBPAGE_PROT) += subpage-prot.o
obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o
obj-$(CONFIG_HIGHMEM) += highmem.o
77 changes: 77 additions & 0 deletions trunk/arch/powerpc/mm/highmem.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,77 @@
/*
* highmem.c: virtual kernel memory mappings for high memory
*
* PowerPC version, stolen from the i386 version.
*
* Used in CONFIG_HIGHMEM systems for memory pages which
* are not addressable by direct kernel virtual addresses.
*
* Copyright (C) 1999 Gerhard Wichert, Siemens AG
* Gerhard.Wichert@pdb.siemens.de
*
*
* Redesigned the x86 32-bit VM architecture to deal with
* up to 16 Terrabyte physical memory. With current x86 CPUs
* we now support up to 64 Gigabytes physical RAM.
*
* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
*
* Reworked for PowerPC by various contributors. Moved from
* highmem.h by Benjamin Herrenschmidt (c) 2009 IBM Corp.
*/

#include <linux/highmem.h>
#include <linux/module.h>

/*
* The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
* gives a more generic (and caching) interface. But kmap_atomic can
* be used in IRQ contexts, so in some (very limited) cases we need
* it.
*/
void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
{
unsigned int idx;
unsigned long vaddr;

/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);

debug_kmap_atomic(type);
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(*(kmap_pte-idx)));
#endif
__set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot), 1);
local_flush_tlb_page(NULL, vaddr);

return (void*) vaddr;
}
EXPORT_SYMBOL(kmap_atomic_prot);

void kunmap_atomic(void *kvaddr, enum km_type type)
{
#ifdef CONFIG_DEBUG_HIGHMEM
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();

if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
pagefault_enable();
return;
}

BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));

/*
* force other mappings to Oops if they'll try to access
* this pte without first remap it
*/
pte_clear(&init_mm, vaddr, kmap_pte-idx);
local_flush_tlb_page(NULL, vaddr);
#endif
pagefault_enable();
}
EXPORT_SYMBOL(kunmap_atomic);

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