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	preempt_disable();
40	pagefault_disable();
41
42	idx = FIX_CMAP_END -
43		(((addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1)) +
44		 (FIX_N_COLOURS * smp_processor_id()));
45
46	vaddr = __fix_to_virt(idx);
47
48	BUG_ON(!pte_none(*(kmap_coherent_pte - idx)));
49	set_pte(kmap_coherent_pte - idx, mk_pte(page, PAGE_KERNEL));
50
51	return (void *)vaddr;
52}
53
54void kunmap_coherent(void *kvaddr)
55{
56	if (kvaddr >= (void *)FIXADDR_START) {
57		unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK;
58		enum fixed_addresses idx = __virt_to_fix(vaddr);
59
60		/* XXX.. Kill this later, here for sanity at the moment.. */
61		__flush_purge_region((void *)vaddr, PAGE_SIZE);
62
63		pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx);
64		local_flush_tlb_one(get_asid(), vaddr);
65	}
66
67	pagefault_enable();
68	preempt_enable();
69}
70