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1// SPDX-License-Identifier: GPL-2.0
2// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3
4#include <linux/module.h>
5#include <linux/highmem.h>
6#include <linux/smp.h>
7#include <linux/memblock.h>
8#include <asm/fixmap.h>
9#include <asm/tlbflush.h>
10#include <asm/cacheflush.h>
11
12static pte_t *kmap_pte;
13
14unsigned long highstart_pfn, highend_pfn;
15
16void *kmap(struct page *page)
17{
18 void *addr;
19
20 might_sleep();
21 if (!PageHighMem(page))
22 return page_address(page);
23 addr = kmap_high(page);
24 flush_tlb_one((unsigned long)addr);
25
26 return addr;
27}
28EXPORT_SYMBOL(kmap);
29
30void kunmap(struct page *page)
31{
32 BUG_ON(in_interrupt());
33 if (!PageHighMem(page))
34 return;
35 kunmap_high(page);
36}
37EXPORT_SYMBOL(kunmap);
38
39void *kmap_atomic(struct page *page)
40{
41 unsigned long vaddr;
42 int idx, type;
43
44 preempt_disable();
45 pagefault_disable();
46 if (!PageHighMem(page))
47 return page_address(page);
48
49 type = kmap_atomic_idx_push();
50 idx = type + KM_TYPE_NR*smp_processor_id();
51 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
52#ifdef CONFIG_DEBUG_HIGHMEM
53 BUG_ON(!pte_none(*(kmap_pte - idx)));
54#endif
55 set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL));
56 flush_tlb_one((unsigned long)vaddr);
57
58 return (void *)vaddr;
59}
60EXPORT_SYMBOL(kmap_atomic);
61
62void __kunmap_atomic(void *kvaddr)
63{
64 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
65 int idx;
66
67 if (vaddr < FIXADDR_START)
68 goto out;
69
70#ifdef CONFIG_DEBUG_HIGHMEM
71 idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
72
73 BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
74
75 pte_clear(&init_mm, vaddr, kmap_pte - idx);
76 flush_tlb_one(vaddr);
77#else
78 (void) idx; /* to kill a warning */
79#endif
80 kmap_atomic_idx_pop();
81out:
82 pagefault_enable();
83 preempt_enable();
84}
85EXPORT_SYMBOL(__kunmap_atomic);
86
87/*
88 * This is the same as kmap_atomic() but can map memory that doesn't
89 * have a struct page associated with it.
90 */
91void *kmap_atomic_pfn(unsigned long pfn)
92{
93 unsigned long vaddr;
94 int idx, type;
95
96 pagefault_disable();
97
98 type = kmap_atomic_idx_push();
99 idx = type + KM_TYPE_NR*smp_processor_id();
100 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
101 set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
102 flush_tlb_one(vaddr);
103
104 return (void *) vaddr;
105}
106
107struct page *kmap_atomic_to_page(void *ptr)
108{
109 unsigned long idx, vaddr = (unsigned long)ptr;
110 pte_t *pte;
111
112 if (vaddr < FIXADDR_START)
113 return virt_to_page(ptr);
114
115 idx = virt_to_fix(vaddr);
116 pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
117 return pte_page(*pte);
118}
119
120static void __init fixrange_init(unsigned long start, unsigned long end,
121 pgd_t *pgd_base)
122{
123#ifdef CONFIG_HIGHMEM
124 pgd_t *pgd;
125 pud_t *pud;
126 pmd_t *pmd;
127 pte_t *pte;
128 int i, j, k;
129 unsigned long vaddr;
130
131 vaddr = start;
132 i = __pgd_offset(vaddr);
133 j = __pud_offset(vaddr);
134 k = __pmd_offset(vaddr);
135 pgd = pgd_base + i;
136
137 for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
138 pud = (pud_t *)pgd;
139 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
140 pmd = (pmd_t *)pud;
141 for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
142 if (pmd_none(*pmd)) {
143 pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
144 if (!pte)
145 panic("%s: Failed to allocate %lu bytes align=%lx\n",
146 __func__, PAGE_SIZE,
147 PAGE_SIZE);
148
149 set_pmd(pmd, __pmd(__pa(pte)));
150 BUG_ON(pte != pte_offset_kernel(pmd, 0));
151 }
152 vaddr += PMD_SIZE;
153 }
154 k = 0;
155 }
156 j = 0;
157 }
158#endif
159}
160
161void __init fixaddr_kmap_pages_init(void)
162{
163 unsigned long vaddr;
164 pgd_t *pgd_base;
165#ifdef CONFIG_HIGHMEM
166 pgd_t *pgd;
167 pmd_t *pmd;
168 pud_t *pud;
169 pte_t *pte;
170#endif
171 pgd_base = swapper_pg_dir;
172
173 /*
174 * Fixed mappings:
175 */
176 vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
177 fixrange_init(vaddr, 0, pgd_base);
178
179#ifdef CONFIG_HIGHMEM
180 /*
181 * Permanent kmaps:
182 */
183 vaddr = PKMAP_BASE;
184 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
185
186 pgd = swapper_pg_dir + __pgd_offset(vaddr);
187 pud = (pud_t *)pgd;
188 pmd = pmd_offset(pud, vaddr);
189 pte = pte_offset_kernel(pmd, vaddr);
190 pkmap_page_table = pte;
191#endif
192}
193
194void __init kmap_init(void)
195{
196 unsigned long vaddr;
197
198 fixaddr_kmap_pages_init();
199
200 vaddr = __fix_to_virt(FIX_KMAP_BEGIN);
201
202 kmap_pte = pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr);
203}
1// SPDX-License-Identifier: GPL-2.0
2// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3
4#include <linux/module.h>
5#include <linux/highmem.h>
6#include <linux/smp.h>
7#include <linux/memblock.h>
8#include <asm/fixmap.h>
9#include <asm/tlbflush.h>
10#include <asm/cacheflush.h>
11
12unsigned long highstart_pfn, highend_pfn;
13
14void kmap_flush_tlb(unsigned long addr)
15{
16 flush_tlb_one(addr);
17}
18EXPORT_SYMBOL(kmap_flush_tlb);
19
20void __init kmap_init(void)
21{
22 unsigned long vaddr;
23 pgd_t *pgd;
24 pmd_t *pmd;
25 pud_t *pud;
26 pte_t *pte;
27
28 vaddr = PKMAP_BASE;
29 fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir);
30
31 pgd = swapper_pg_dir + pgd_index(vaddr);
32 pud = (pud_t *)pgd;
33 pmd = pmd_offset(pud, vaddr);
34 pte = pte_offset_kernel(pmd, vaddr);
35 pkmap_page_table = pte;
36}