1/*
2 * arch/sh/mm/kmap.c
3 *
4 * Copyright (C) 1999, 2000, 2002  Niibe Yutaka
5 * Copyright (C) 2002 - 2009  Paul Mundt
6 *
7 * Released under the terms of the GNU GPL v2.0.
8 */
9#include <linux/mm.h>
10#include <linux/init.h>
11#include <linux/mutex.h>
12#include <linux/fs.h>
13#include <linux/highmem.h>
14#include <linux/module.h>
15#include <asm/mmu_context.h>
16#include <asm/cacheflush.h>
17
18#define kmap_get_fixmap_pte(vaddr)                                     \
19	pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
20
21static pte_t *kmap_coherent_pte;
22
23void __init kmap_coherent_init(void)
24{
25	unsigned long vaddr;
26
27	/* cache the first coherent kmap pte */
28	vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
29	kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
30}
31
32void *kmap_coherent(struct page *page, unsigned long addr)
33{
34	enum fixed_addresses idx;
35	unsigned long vaddr;
36
37	BUG_ON(!test_bit(PG_dcache_clean, &page->flags));
38
39	pagefault_disable();
40
41	idx = FIX_CMAP_END -
42		(((addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1)) +
43		 (FIX_N_COLOURS * smp_processor_id()));
44
45	vaddr = __fix_to_virt(idx);
46
47	BUG_ON(!pte_none(*(kmap_coherent_pte - idx)));
48	set_pte(kmap_coherent_pte - idx, mk_pte(page, PAGE_KERNEL));
49
50	return (void *)vaddr;
51}
52
53void kunmap_coherent(void *kvaddr)
54{
55	if (kvaddr >= (void *)FIXADDR_START) {
56		unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK;
57		enum fixed_addresses idx = __virt_to_fix(vaddr);
58
59		/* XXX.. Kill this later, here for sanity at the moment.. */
60		__flush_purge_region((void *)vaddr, PAGE_SIZE);
61
62		pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx);
63		local_flush_tlb_one(get_asid(), vaddr);
64	}
65
66	pagefault_enable();
67}
68