1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * arch/sh/mm/kmap.c
4 *
5 * Copyright (C) 1999, 2000, 2002 Niibe Yutaka
6 * Copyright (C) 2002 - 2009 Paul Mundt
7 */
8 #include <linux/mm.h>
9 #include <linux/init.h>
10 #include <linux/mutex.h>
11 #include <linux/fs.h>
12 #include <linux/highmem.h>
13 #include <linux/module.h>
14 #include <asm/mmu_context.h>
15 #include <asm/cacheflush.h>
16
17 #define kmap_get_fixmap_pte(vaddr) \
18 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
19
20 static pte_t *kmap_coherent_pte;
21
kmap_coherent_init(void)22 void __init kmap_coherent_init(void)
23 {
24 unsigned long vaddr;
25
26 /* cache the first coherent kmap pte */
27 vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
28 kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
29 }
30
kmap_coherent(struct page * page,unsigned long addr)31 void *kmap_coherent(struct page *page, unsigned long addr)
32 {
33 enum fixed_addresses idx;
34 unsigned long vaddr;
35
36 BUG_ON(!test_bit(PG_dcache_clean, &page->flags));
37
38 preempt_disable();
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
kunmap_coherent(void * kvaddr)53 void 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 preempt_enable();
68 }
69