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
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
|
/*
* x86_64 specific EFI support functions
* Based on Extensible Firmware Interface Specification version 1.0
*
* Copyright (C) 2005-2008 Intel Co.
* Fenghua Yu <fenghua.yu@intel.com>
* Bibo Mao <bibo.mao@intel.com>
* Chandramouli Narayanan <mouli@linux.intel.com>
* Huang Ying <ying.huang@intel.com>
*
* Code to convert EFI to E820 map has been implemented in elilo bootloader
* based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
* is setup appropriately for EFI runtime code.
* - mouli 06/14/2007.
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/bootmem.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/efi.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <asm/setup.h>
#include <asm/page.h>
#include <asm/e820.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/proto.h>
#include <asm/efi.h>
#include <asm/cacheflush.h>
#include <asm/fixmap.h>
#include <asm/realmode.h>
static pgd_t *save_pgd __initdata;
static unsigned long efi_flags __initdata;
/*
* We allocate runtime services regions bottom-up, starting from -4G, i.e.
* 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G.
*/
static u64 efi_va = -4 * (1UL << 30);
#define EFI_VA_END (-68 * (1UL << 30))
/*
* Scratch space used for switching the pagetable in the EFI stub
*/
struct efi_scratch {
u64 r15;
u64 prev_cr3;
pgd_t *efi_pgt;
bool use_pgd;
};
static void __init early_code_mapping_set_exec(int executable)
{
efi_memory_desc_t *md;
void *p;
if (!(__supported_pte_mask & _PAGE_NX))
return;
/* Make EFI service code area executable */
for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
md = p;
if (md->type == EFI_RUNTIME_SERVICES_CODE ||
md->type == EFI_BOOT_SERVICES_CODE)
efi_set_executable(md, executable);
}
}
void __init efi_call_phys_prelog(void)
{
unsigned long vaddress;
int pgd;
int n_pgds;
if (!efi_enabled(EFI_OLD_MEMMAP))
return;
early_code_mapping_set_exec(1);
local_irq_save(efi_flags);
n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
save_pgd = kmalloc(n_pgds * sizeof(pgd_t), GFP_KERNEL);
for (pgd = 0; pgd < n_pgds; pgd++) {
save_pgd[pgd] = *pgd_offset_k(pgd * PGDIR_SIZE);
vaddress = (unsigned long)__va(pgd * PGDIR_SIZE);
set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), *pgd_offset_k(vaddress));
}
__flush_tlb_all();
}
void __init efi_call_phys_epilog(void)
{
/*
* After the lock is released, the original page table is restored.
*/
int pgd;
int n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
if (!efi_enabled(EFI_OLD_MEMMAP))
return;
for (pgd = 0; pgd < n_pgds; pgd++)
set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), save_pgd[pgd]);
kfree(save_pgd);
__flush_tlb_all();
local_irq_restore(efi_flags);
early_code_mapping_set_exec(0);
}
/*
* Add low kernel mappings for passing arguments to EFI functions.
*/
void efi_sync_low_kernel_mappings(void)
{
unsigned num_pgds;
pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
if (efi_enabled(EFI_OLD_MEMMAP))
return;
num_pgds = pgd_index(MODULES_END - 1) - pgd_index(PAGE_OFFSET);
memcpy(pgd + pgd_index(PAGE_OFFSET),
init_mm.pgd + pgd_index(PAGE_OFFSET),
sizeof(pgd_t) * num_pgds);
}
void efi_setup_page_tables(void)
{
efi_scratch.efi_pgt = (pgd_t *)(unsigned long)real_mode_header->trampoline_pgd;
if (!efi_enabled(EFI_OLD_MEMMAP))
efi_scratch.use_pgd = true;
}
static void __init __map_region(efi_memory_desc_t *md, u64 va)
{
pgd_t *pgd = (pgd_t *)__va(real_mode_header->trampoline_pgd);
unsigned long pf = 0;
if (!(md->attribute & EFI_MEMORY_WB))
pf |= _PAGE_PCD;
if (kernel_map_pages_in_pgd(pgd, md->phys_addr, va, md->num_pages, pf))
pr_warn("Error mapping PA 0x%llx -> VA 0x%llx!\n",
md->phys_addr, va);
}
void __init efi_map_region(efi_memory_desc_t *md)
{
unsigned long size = md->num_pages << PAGE_SHIFT;
u64 pa = md->phys_addr;
if (efi_enabled(EFI_OLD_MEMMAP))
return old_map_region(md);
/*
* Make sure the 1:1 mappings are present as a catch-all for b0rked
* firmware which doesn't update all internal pointers after switching
* to virtual mode and would otherwise crap on us.
*/
__map_region(md, md->phys_addr);
efi_va -= size;
/* Is PA 2M-aligned? */
if (!(pa & (PMD_SIZE - 1))) {
efi_va &= PMD_MASK;
} else {
u64 pa_offset = pa & (PMD_SIZE - 1);
u64 prev_va = efi_va;
/* get us the same offset within this 2M page */
efi_va = (efi_va & PMD_MASK) + pa_offset;
if (efi_va > prev_va)
efi_va -= PMD_SIZE;
}
if (efi_va < EFI_VA_END) {
pr_warn(FW_WARN "VA address range overflow!\n");
return;
}
/* Do the VA map */
__map_region(md, efi_va);
md->virt_addr = efi_va;
}
/*
* kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges.
* md->virt_addr is the original virtual address which had been mapped in kexec
* 1st kernel.
*/
void __init efi_map_region_fixed(efi_memory_desc_t *md)
{
__map_region(md, md->virt_addr);
}
void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
u32 type, u64 attribute)
{
unsigned long last_map_pfn;
if (type == EFI_MEMORY_MAPPED_IO)
return ioremap(phys_addr, size);
last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) {
unsigned long top = last_map_pfn << PAGE_SHIFT;
efi_ioremap(top, size - (top - phys_addr), type, attribute);
}
if (!(attribute & EFI_MEMORY_WB))
efi_memory_uc((u64)(unsigned long)__va(phys_addr), size);
return (void __iomem *)__va(phys_addr);
}
void __init parse_efi_setup(u64 phys_addr, u32 data_len)
{
efi_setup = phys_addr + sizeof(struct setup_data);
}
void __init efi_runtime_mkexec(void)
{
if (!efi_enabled(EFI_OLD_MEMMAP))
return;
if (__supported_pte_mask & _PAGE_NX)
runtime_code_page_mkexec();
}
|
