1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * arch/sh/mm/kmap.c
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 1999, 2000, 2002 Niibe Yutaka
6*4882a593Smuzhiyun * Copyright (C) 2002 - 2009 Paul Mundt
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun #include <linux/mm.h>
9*4882a593Smuzhiyun #include <linux/init.h>
10*4882a593Smuzhiyun #include <linux/mutex.h>
11*4882a593Smuzhiyun #include <linux/fs.h>
12*4882a593Smuzhiyun #include <linux/highmem.h>
13*4882a593Smuzhiyun #include <linux/module.h>
14*4882a593Smuzhiyun #include <asm/mmu_context.h>
15*4882a593Smuzhiyun #include <asm/cacheflush.h>
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun static pte_t *kmap_coherent_pte;
18*4882a593Smuzhiyun
kmap_coherent_init(void)19*4882a593Smuzhiyun void __init kmap_coherent_init(void)
20*4882a593Smuzhiyun {
21*4882a593Smuzhiyun unsigned long vaddr;
22*4882a593Smuzhiyun
23*4882a593Smuzhiyun /* cache the first coherent kmap pte */
24*4882a593Smuzhiyun vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
25*4882a593Smuzhiyun kmap_coherent_pte = virt_to_kpte(vaddr);
26*4882a593Smuzhiyun }
27*4882a593Smuzhiyun
kmap_coherent(struct page * page,unsigned long addr)28*4882a593Smuzhiyun void *kmap_coherent(struct page *page, unsigned long addr)
29*4882a593Smuzhiyun {
30*4882a593Smuzhiyun enum fixed_addresses idx;
31*4882a593Smuzhiyun unsigned long vaddr;
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun BUG_ON(!test_bit(PG_dcache_clean, &page->flags));
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun preempt_disable();
36*4882a593Smuzhiyun pagefault_disable();
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun idx = FIX_CMAP_END -
39*4882a593Smuzhiyun (((addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1)) +
40*4882a593Smuzhiyun (FIX_N_COLOURS * smp_processor_id()));
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun vaddr = __fix_to_virt(idx);
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun BUG_ON(!pte_none(*(kmap_coherent_pte - idx)));
45*4882a593Smuzhiyun set_pte(kmap_coherent_pte - idx, mk_pte(page, PAGE_KERNEL));
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun return (void *)vaddr;
48*4882a593Smuzhiyun }
49*4882a593Smuzhiyun
kunmap_coherent(void * kvaddr)50*4882a593Smuzhiyun void kunmap_coherent(void *kvaddr)
51*4882a593Smuzhiyun {
52*4882a593Smuzhiyun if (kvaddr >= (void *)FIXADDR_START) {
53*4882a593Smuzhiyun unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK;
54*4882a593Smuzhiyun enum fixed_addresses idx = __virt_to_fix(vaddr);
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun /* XXX.. Kill this later, here for sanity at the moment.. */
57*4882a593Smuzhiyun __flush_purge_region((void *)vaddr, PAGE_SIZE);
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx);
60*4882a593Smuzhiyun local_flush_tlb_one(get_asid(), vaddr);
61*4882a593Smuzhiyun }
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun pagefault_enable();
64*4882a593Smuzhiyun preempt_enable();
65*4882a593Smuzhiyun }
66