Release 4.11 arch/sparc/mm/highmem.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/highmem.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/pgalloc.h>
#include <asm/vaddrs.h>
pgprot_t kmap_prot;
static pte_t *kmap_pte;
void __init kmap_init(void)
{
unsigned long address;
pmd_t *dir;
address = __fix_to_virt(FIX_KMAP_BEGIN);
dir = pmd_offset(pgd_offset_k(address), address);
/* cache the first kmap pte */
kmap_pte = pte_offset_kernel(dir, address);
kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Sam Ravnborg | 56 | 100.00% | 1 | 100.00% |
| Total | 56 | 100.00% | 1 | 100.00% |
void *kmap_atomic(struct page *page)
{
unsigned long vaddr;
long idx, type;
preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
type = kmap_atomic_idx_push();
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;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| David S. Miller | 97 | 76.38% | 1 | 12.50% |
| Keith M. Wesolowski | 12 | 9.45% | 1 | 12.50% |
| Peter Zijlstra | 8 | 6.30% | 2 | 25.00% |
| Dave Hansen | 4 | 3.15% | 1 | 12.50% |
| David Hildenbrand | 3 | 2.36% | 1 | 12.50% |
| Akinobu Mita | 2 | 1.57% | 1 | 12.50% |
| Américo Wang | 1 | 0.79% | 1 | 12.50% |
| Total | 127 | 100.00% | 8 | 100.00% |
EXPORT_SYMBOL(kmap_atomic);
void __kunmap_atomic(void *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
int type;
if (vaddr < FIXADDR_START) { // FIXME
pagefault_enable();
preempt_enable();
return;
}
type = kmap_atomic_idx();
#ifdef CONFIG_DEBUG_HIGHMEM
{
unsigned long idx;
idx = type + KM_TYPE_NR * smp_processor_id();
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
kmap_atomic_idx_pop();
pagefault_enable();
preempt_enable();
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| David S. Miller | 71 | 57.72% | 2 | 25.00% |
| Peter Zijlstra | 31 | 25.20% | 3 | 37.50% |
| Keith M. Wesolowski | 11 | 8.94% | 1 | 12.50% |
| David Hildenbrand | 6 | 4.88% | 1 | 12.50% |
| Andrew Morton | 4 | 3.25% | 1 | 12.50% |
| Total | 123 | 100.00% | 8 | 100.00% |
EXPORT_SYMBOL(__kunmap_atomic);
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| David S. Miller | 181 | 52.16% | 2 | 13.33% |
| Sam Ravnborg | 77 | 22.19% | 3 | 20.00% |
| Peter Zijlstra | 40 | 11.53% | 3 | 20.00% |
| Keith M. Wesolowski | 25 | 7.20% | 1 | 6.67% |
| David Hildenbrand | 9 | 2.59% | 1 | 6.67% |
| Dave Hansen | 4 | 1.15% | 1 | 6.67% |
| Andrew Morton | 4 | 1.15% | 1 | 6.67% |
| Paul Gortmaker | 3 | 0.86% | 1 | 6.67% |
| Américo Wang | 2 | 0.58% | 1 | 6.67% |
| Akinobu Mita | 2 | 0.58% | 1 | 6.67% |
| Total | 347 | 100.00% | 15 | 100.00% |
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