1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <linux/compiler.h>
3*4882a593Smuzhiyun #include <linux/init.h>
4*4882a593Smuzhiyun #include <linux/export.h>
5*4882a593Smuzhiyun #include <linux/highmem.h>
6*4882a593Smuzhiyun #include <linux/sched.h>
7*4882a593Smuzhiyun #include <linux/smp.h>
8*4882a593Smuzhiyun #include <asm/fixmap.h>
9*4882a593Smuzhiyun #include <asm/tlbflush.h>
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun static pte_t *kmap_pte;
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun unsigned long highstart_pfn, highend_pfn;
14*4882a593Smuzhiyun
kmap_flush_tlb(unsigned long addr)15*4882a593Smuzhiyun void kmap_flush_tlb(unsigned long addr)
16*4882a593Smuzhiyun {
17*4882a593Smuzhiyun flush_tlb_one(addr);
18*4882a593Smuzhiyun }
19*4882a593Smuzhiyun EXPORT_SYMBOL(kmap_flush_tlb);
20*4882a593Smuzhiyun
kmap_atomic_high_prot(struct page * page,pgprot_t prot)21*4882a593Smuzhiyun void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
22*4882a593Smuzhiyun {
23*4882a593Smuzhiyun unsigned long vaddr;
24*4882a593Smuzhiyun int idx, type;
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun type = kmap_atomic_idx_push();
27*4882a593Smuzhiyun idx = type + KM_TYPE_NR*smp_processor_id();
28*4882a593Smuzhiyun vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
29*4882a593Smuzhiyun #ifdef CONFIG_DEBUG_HIGHMEM
30*4882a593Smuzhiyun BUG_ON(!pte_none(*(kmap_pte - idx)));
31*4882a593Smuzhiyun #endif
32*4882a593Smuzhiyun set_pte(kmap_pte-idx, mk_pte(page, prot));
33*4882a593Smuzhiyun local_flush_tlb_one((unsigned long)vaddr);
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun return (void*) vaddr;
36*4882a593Smuzhiyun }
37*4882a593Smuzhiyun EXPORT_SYMBOL(kmap_atomic_high_prot);
38*4882a593Smuzhiyun
kunmap_atomic_high(void * kvaddr)39*4882a593Smuzhiyun void kunmap_atomic_high(void *kvaddr)
40*4882a593Smuzhiyun {
41*4882a593Smuzhiyun unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
42*4882a593Smuzhiyun int type __maybe_unused;
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun if (vaddr < FIXADDR_START)
45*4882a593Smuzhiyun return;
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun type = kmap_atomic_idx();
48*4882a593Smuzhiyun #ifdef CONFIG_DEBUG_HIGHMEM
49*4882a593Smuzhiyun {
50*4882a593Smuzhiyun int idx = type + KM_TYPE_NR * smp_processor_id();
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun /*
55*4882a593Smuzhiyun * force other mappings to Oops if they'll try to access
56*4882a593Smuzhiyun * this pte without first remap it
57*4882a593Smuzhiyun */
58*4882a593Smuzhiyun pte_clear(&init_mm, vaddr, kmap_pte-idx);
59*4882a593Smuzhiyun local_flush_tlb_one(vaddr);
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun #endif
62*4882a593Smuzhiyun kmap_atomic_idx_pop();
63*4882a593Smuzhiyun }
64*4882a593Smuzhiyun EXPORT_SYMBOL(kunmap_atomic_high);
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun /*
67*4882a593Smuzhiyun * This is the same as kmap_atomic() but can map memory that doesn't
68*4882a593Smuzhiyun * have a struct page associated with it.
69*4882a593Smuzhiyun */
kmap_atomic_pfn(unsigned long pfn)70*4882a593Smuzhiyun void *kmap_atomic_pfn(unsigned long pfn)
71*4882a593Smuzhiyun {
72*4882a593Smuzhiyun unsigned long vaddr;
73*4882a593Smuzhiyun int idx, type;
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun preempt_disable();
76*4882a593Smuzhiyun pagefault_disable();
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun type = kmap_atomic_idx_push();
79*4882a593Smuzhiyun idx = type + KM_TYPE_NR*smp_processor_id();
80*4882a593Smuzhiyun vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
81*4882a593Smuzhiyun set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
82*4882a593Smuzhiyun flush_tlb_one(vaddr);
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun return (void*) vaddr;
85*4882a593Smuzhiyun }
86*4882a593Smuzhiyun
kmap_init(void)87*4882a593Smuzhiyun void __init kmap_init(void)
88*4882a593Smuzhiyun {
89*4882a593Smuzhiyun unsigned long kmap_vstart;
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun /* cache the first kmap pte */
92*4882a593Smuzhiyun kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
93*4882a593Smuzhiyun kmap_pte = virt_to_kpte(kmap_vstart);
94*4882a593Smuzhiyun }
95