diff options
Diffstat (limited to 'arch/sh/mm/kmap.c')
-rw-r--r-- | arch/sh/mm/kmap.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/arch/sh/mm/kmap.c b/arch/sh/mm/kmap.c new file mode 100644 index 000000000..bf25d7c79 --- /dev/null +++ b/arch/sh/mm/kmap.c @@ -0,0 +1,69 @@ +/* + * arch/sh/mm/kmap.c + * + * Copyright (C) 1999, 2000, 2002 Niibe Yutaka + * Copyright (C) 2002 - 2009 Paul Mundt + * + * Released under the terms of the GNU GPL v2.0. + */ +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/mutex.h> +#include <linux/fs.h> +#include <linux/highmem.h> +#include <linux/module.h> +#include <asm/mmu_context.h> +#include <asm/cacheflush.h> + +#define kmap_get_fixmap_pte(vaddr) \ + pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr)) + +static pte_t *kmap_coherent_pte; + +void __init kmap_coherent_init(void) +{ + unsigned long vaddr; + + /* cache the first coherent kmap pte */ + vaddr = __fix_to_virt(FIX_CMAP_BEGIN); + kmap_coherent_pte = kmap_get_fixmap_pte(vaddr); +} + +void *kmap_coherent(struct page *page, unsigned long addr) +{ + enum fixed_addresses idx; + unsigned long vaddr; + + BUG_ON(!test_bit(PG_dcache_clean, &page->flags)); + + preempt_disable(); + pagefault_disable(); + + idx = FIX_CMAP_END - + (((addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1)) + + (FIX_N_COLOURS * smp_processor_id())); + + vaddr = __fix_to_virt(idx); + + 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 *kvaddr) +{ + if (kvaddr >= (void *)FIXADDR_START) { + unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK; + enum fixed_addresses idx = __virt_to_fix(vaddr); + + /* XXX.. Kill this later, here for sanity at the moment.. */ + __flush_purge_region((void *)vaddr, PAGE_SIZE); + + pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx); + local_flush_tlb_one(get_asid(), vaddr); + } + + pagefault_enable(); + preempt_enable(); +} |