4 * Copyright (C) 1999, 2000, 2002 Niibe Yutaka
5 * Copyright (C) 2002 - 2009 Paul Mundt
7 * Released under the terms of the GNU GPL v2.0.
10 #include <linux/init.h>
11 #include <linux/mutex.h>
13 #include <linux/highmem.h>
14 #include <linux/module.h>
15 #include <asm/mmu_context.h>
16 #include <asm/cacheflush.h>
18 #define kmap_get_fixmap_pte(vaddr) \
19 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
21 static pte_t *kmap_coherent_pte;
23 void __init kmap_coherent_init(void)
27 if (!boot_cpu_data.dcache.n_aliases)
30 /* cache the first coherent kmap pte */
31 vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
32 kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
35 void *kmap_coherent(struct page *page, unsigned long addr)
37 enum fixed_addresses idx;
38 unsigned long vaddr, flags;
41 BUG_ON(test_bit(PG_dcache_dirty, &page->flags));
45 idx = (addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT;
46 vaddr = __fix_to_virt(FIX_CMAP_END - idx);
47 pte = mk_pte(page, PAGE_KERNEL);
49 local_irq_save(flags);
50 flush_tlb_one(get_asid(), vaddr);
51 local_irq_restore(flags);
53 update_mmu_cache(NULL, vaddr, pte);
55 set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
60 void kunmap_coherent(void)
63 preempt_check_resched();