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 static pte_t *kmap_coherent_pte;
18
19 void __init kmap_coherent_init(void)
20 {
21 unsigned long vaddr;
22
23 /* cache the first coherent kmap pte */
24 vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
25 kmap_coherent_pte = virt_to_kpte(vaddr);
26 }
27
28 void *kmap_coherent(struct page *page, unsigned long addr)
29 {
30 struct folio *folio = page_folio(page);
31 enum fixed_addresses idx;
32 unsigned long vaddr;
33
34 BUG_ON(!test_bit(PG_dcache_clean, &folio->flags));
35
36 preempt_disable();
37 pagefault_disable();
38
39 idx = FIX_CMAP_END -
40 (((addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1)) +
41 (FIX_N_COLOURS * smp_processor_id()));
42
43 vaddr = __fix_to_virt(idx);
44
45 BUG_ON(!pte_none(*(kmap_coherent_pte - idx)));
46 set_pte(kmap_coherent_pte - idx, mk_pte(page, PAGE_KERNEL));
47
48 return (void *)vaddr;
49 }
50
51 void kunmap_coherent(void *kvaddr)
52 {
53 if (kvaddr >= (void *)FIXADDR_START) {
54 unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK;
55 enum fixed_addresses idx = __virt_to_fix(vaddr);
56
57 /* XXX.. Kill this later, here for sanity at the moment.. */
58 __flush_purge_region((void *)vaddr, PAGE_SIZE);
59
60 pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx);
61 local_flush_tlb_one(get_asid(), vaddr);
62 }
63
64 pagefault_enable();
65 preempt_enable();
66 }
67
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