linux/arch/sparc/mm/highmem.c
Sam Ravnborg 6943f3da3e sparc: move EXPORT_SYMBOL to the symbols definition
Move all applicable EXPORT_SYMBOL()s to the file where the respective
symbol is defined.

Removed all the includes that are no longer needed in sparc_ksyms_32.c

Comment all remaining EXPORT_SYMBOL()s in sparc_ksyms_32.c

Two symbols are shared with sparc64 thus the exports were removed from
the sparc_ksyms_64.c too, along with the include their ommission made
redundant.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Additions by Julian Calaby:
* Moved EXPORT_SYMBOL()s for prom functions to their rightful places.
* Made some minor cleanups to the includes and comments of sparc_ksyms_32.c
* Made another subtraction from sparc_ksyms_64.c
* Updated and tidied commit message.
* Rebased patch over sparc-2.6.git HEAD.
* Ensured that all modified files have the correct includes.

Signed-off-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-08 16:58:05 -08:00

121 lines
3.0 KiB
C

/*
* highmem.c: virtual kernel memory mappings for high memory
*
* Provides kernel-static versions of atomic kmap functions originally
* found as inlines in include/asm-sparc/highmem.h. These became
* needed as kmap_atomic() and kunmap_atomic() started getting
* called from within modules.
* -- Tomas Szepe <szepe@pinerecords.com>, September 2002
*
* But kmap_atomic() and kunmap_atomic() cannot be inlined in
* modules because they are loaded with btfixup-ped functions.
*/
/*
* 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.
*
* XXX This is an old text. Actually, it's good to use atomic kmaps,
* provided you remember that they are atomic and not try to sleep
* with a kmap taken, much like a spinlock. Non-atomic kmaps are
* shared by CPUs, and so precious, and establishing them requires IPI.
* Atomic kmaps are lightweight and we may have NCPUS more of them.
*/
#include <linux/mm.h>
#include <linux/highmem.h>
#include <asm/pgalloc.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/fixmap.h>
void *kmap_atomic(struct page *page, enum km_type type)
{
unsigned long 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);
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
/* XXX Fix - Anton */
#if 0
__flush_cache_one(vaddr);
#else
flush_cache_all();
#endif
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(*(kmap_pte-idx)));
#endif
set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
/* XXX Fix - Anton */
#if 0
__flush_tlb_one(vaddr);
#else
flush_tlb_all();
#endif
return (void*) vaddr;
}
EXPORT_SYMBOL(kmap_atomic);
void kunmap_atomic(void *kvaddr, enum km_type type)
{
#ifdef CONFIG_DEBUG_HIGHMEM
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
unsigned long idx = type + KM_TYPE_NR*smp_processor_id();
if (vaddr < FIXADDR_START) { // FIXME
pagefault_enable();
return;
}
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx));
/* XXX Fix - Anton */
#if 0
__flush_cache_one(vaddr);
#else
flush_cache_all();
#endif
/*
* 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);
/* XXX Fix - Anton */
#if 0
__flush_tlb_one(vaddr);
#else
flush_tlb_all();
#endif
#endif
pagefault_enable();
}
EXPORT_SYMBOL(kunmap_atomic);
/* We may be fed a pagetable here by ptep_to_xxx and others. */
struct page *kmap_atomic_to_page(void *ptr)
{
unsigned long idx, vaddr = (unsigned long)ptr;
pte_t *pte;
if (vaddr < SRMMU_NOCACHE_VADDR)
return virt_to_page(ptr);
if (vaddr < PKMAP_BASE)
return pfn_to_page(__nocache_pa(vaddr) >> PAGE_SHIFT);
BUG_ON(vaddr < FIXADDR_START);
BUG_ON(vaddr > FIXADDR_TOP);
idx = virt_to_fix(vaddr);
pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
return pte_page(*pte);
}