1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Fixmap manipulation code
*/
#include <linux/bug.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/libfdt.h>
#include <linux/memory.h>
#include <linux/mm.h>
#include <linux/sizes.h>
#include <asm/fixmap.h>
#include <asm/kernel-pgtable.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
/* ensure that the fixmap region does not grow down into the PCI I/O region */
static_assert(FIXADDR_TOT_START > PCI_IO_END);
#define NR_BM_PTE_TABLES \
SPAN_NR_ENTRIES(FIXADDR_TOT_START, FIXADDR_TOP, PMD_SHIFT)
#define NR_BM_PMD_TABLES \
SPAN_NR_ENTRIES(FIXADDR_TOT_START, FIXADDR_TOP, PUD_SHIFT)
static_assert(NR_BM_PMD_TABLES == 1);
#define __BM_TABLE_IDX(addr, shift) \
(((addr) >> (shift)) - (FIXADDR_TOT_START >> (shift)))
#define BM_PTE_TABLE_IDX(addr) __BM_TABLE_IDX(addr, PMD_SHIFT)
static pte_t bm_pte[NR_BM_PTE_TABLES][PTRS_PER_PTE] __page_aligned_bss;
static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss __maybe_unused;
static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss __maybe_unused;
static inline pte_t *fixmap_pte(unsigned long addr)
{
return &bm_pte[BM_PTE_TABLE_IDX(addr)][pte_index(addr)];
}
static void __init early_fixmap_init_pte(pmd_t *pmdp, unsigned long addr)
{
pmd_t pmd = READ_ONCE(*pmdp);
pte_t *ptep;
if (pmd_none(pmd)) {
ptep = bm_pte[BM_PTE_TABLE_IDX(addr)];
__pmd_populate(pmdp, __pa_symbol(ptep), PMD_TYPE_TABLE);
}
}
static void __init early_fixmap_init_pmd(pud_t *pudp, unsigned long addr,
unsigned long end)
{
unsigned long next;
pud_t pud = READ_ONCE(*pudp);
pmd_t *pmdp;
if (pud_none(pud))
__pud_populate(pudp, __pa_symbol(bm_pmd), PUD_TYPE_TABLE);
pmdp = pmd_offset_kimg(pudp, addr);
do {
next = pmd_addr_end(addr, end);
early_fixmap_init_pte(pmdp, addr);
} while (pmdp++, addr = next, addr != end);
}
static void __init early_fixmap_init_pud(p4d_t *p4dp, unsigned long addr,
unsigned long end)
{
p4d_t p4d = READ_ONCE(*p4dp);
pud_t *pudp;
if (CONFIG_PGTABLE_LEVELS > 3 && !p4d_none(p4d) &&
p4d_page_paddr(p4d) != __pa_symbol(bm_pud)) {
/*
* We only end up here if the kernel mapping and the fixmap
* share the top level pgd entry, which should only happen on
* 16k/4 levels configurations.
*/
BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES));
}
if (p4d_none(p4d))
__p4d_populate(p4dp, __pa_symbol(bm_pud), P4D_TYPE_TABLE);
pudp = pud_offset_kimg(p4dp, addr);
early_fixmap_init_pmd(pudp, addr, end);
}
/*
* The p*d_populate functions call virt_to_phys implicitly so they can't be used
* directly on kernel symbols (bm_p*d). This function is called too early to use
* lm_alias so __p*d_populate functions must be used to populate with the
* physical address from __pa_symbol.
*/
void __init early_fixmap_init(void)
{
unsigned long addr = FIXADDR_TOT_START;
unsigned long end = FIXADDR_TOP;
pgd_t *pgdp = pgd_offset_k(addr);
p4d_t *p4dp = p4d_offset_kimg(pgdp, addr);
early_fixmap_init_pud(p4dp, addr, end);
}
/*
* Unusually, this is also called in IRQ context (ghes_iounmap_irq) so if we
* ever need to use IPIs for TLB broadcasting, then we're in trouble here.
*/
void __set_fixmap(enum fixed_addresses idx,
phys_addr_t phys, pgprot_t flags)
{
unsigned long addr = __fix_to_virt(idx);
pte_t *ptep;
BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
ptep = fixmap_pte(addr);
if (pgprot_val(flags)) {
__set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, flags));
} else {
__pte_clear(&init_mm, addr, ptep);
flush_tlb_kernel_range(addr, addr+PAGE_SIZE);
}
}
void *__init fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
{
const u64 dt_virt_base = __fix_to_virt(FIX_FDT);
phys_addr_t dt_phys_base;
int offset;
void *dt_virt;
/*
* Check whether the physical FDT address is set and meets the minimum
* alignment requirement. Since we are relying on MIN_FDT_ALIGN to be
* at least 8 bytes so that we can always access the magic and size
* fields of the FDT header after mapping the first chunk, double check
* here if that is indeed the case.
*/
BUILD_BUG_ON(MIN_FDT_ALIGN < 8);
if (!dt_phys || dt_phys % MIN_FDT_ALIGN)
return NULL;
dt_phys_base = round_down(dt_phys, PAGE_SIZE);
offset = dt_phys % PAGE_SIZE;
dt_virt = (void *)dt_virt_base + offset;
/* map the first chunk so we can read the size from the header */
create_mapping_noalloc(dt_phys_base, dt_virt_base, PAGE_SIZE, prot);
if (fdt_magic(dt_virt) != FDT_MAGIC)
return NULL;
*size = fdt_totalsize(dt_virt);
if (*size > MAX_FDT_SIZE)
return NULL;
if (offset + *size > PAGE_SIZE) {
create_mapping_noalloc(dt_phys_base, dt_virt_base,
offset + *size, prot);
}
return dt_virt;
}
|
