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authorPaul Mundt <lethal@linux-sh.org>2009-09-03 12:21:10 +0400
committerPaul Mundt <lethal@linux-sh.org>2009-09-03 12:21:10 +0400
commit0906a3ad33a254094fb74828e3ddb9af8771a6da (patch)
tree33acc1be2e213ae2f13439d3d5f8e9dd8a4f2d46 /arch/sh/mm/kmap.c
parentd1af119a69fc9a625bd57a66d9c9fa88795b082c (diff)
downloadlinux-0906a3ad33a254094fb74828e3ddb9af8771a6da.tar.xz
sh: Fix up and optimize the kmap_coherent() interface.
This fixes up the kmap_coherent/kunmap_coherent() interface for recent changes both in the page fault path and the shared cache flushers, as well as adding in some optimizations. One of the key things to note here is that the TLB flush itself is deferred until the unmap, and the call in to update_mmu_cache() itself goes away, relying on the regular page fault path to handle the lazy dcache writeback if necessary. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/mm/kmap.c')
-rw-r--r--arch/sh/mm/kmap.c36
1 files changed, 17 insertions, 19 deletions
diff --git a/arch/sh/mm/kmap.c b/arch/sh/mm/kmap.c
index 3eecf0d42f1a..c52cd8c40a64 100644
--- a/arch/sh/mm/kmap.c
+++ b/arch/sh/mm/kmap.c
@@ -24,9 +24,6 @@ void __init kmap_coherent_init(void)
{
unsigned long vaddr;
- if (!boot_cpu_data.dcache.n_aliases)
- return;
-
/* cache the first coherent kmap pte */
vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
@@ -35,30 +32,31 @@ void __init kmap_coherent_init(void)
void *kmap_coherent(struct page *page, unsigned long addr)
{
enum fixed_addresses idx;
- unsigned long vaddr, flags;
- pte_t pte;
+ unsigned long vaddr;
BUG_ON(test_bit(PG_dcache_dirty, &page->flags));
- inc_preempt_count();
-
- idx = (addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT;
- vaddr = __fix_to_virt(FIX_CMAP_END - idx);
- pte = mk_pte(page, PAGE_KERNEL);
+ pagefault_disable();
- local_irq_save(flags);
- flush_tlb_one(get_asid(), vaddr);
- local_irq_restore(flags);
+ idx = FIX_CMAP_END -
+ ((addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT);
+ vaddr = __fix_to_virt(idx);
- update_mmu_cache(NULL, vaddr, pte);
-
- set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
+ BUG_ON(!pte_none(*(kmap_coherent_pte - idx)));
+ set_pte(kmap_coherent_pte - idx, mk_pte(page, PAGE_KERNEL));
return (void *)vaddr;
}
-void kunmap_coherent(void)
+void kunmap_coherent(void *kvaddr)
{
- dec_preempt_count();
- preempt_check_resched();
+ if (kvaddr >= (void *)FIXADDR_START) {
+ unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK;
+ enum fixed_addresses idx = __virt_to_fix(vaddr);
+
+ pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx);
+ local_flush_tlb_one(get_asid(), vaddr);
+ }
+
+ pagefault_enable();
}