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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
084ee1c6 | 2 | #include <linux/io.h> |
5ff3e2c3 | 3 | #include <linux/slab.h> |
084ee1c6 | 4 | #include <linux/memblock.h> |
163ea3c8 | 5 | #include <linux/mem_encrypt.h> |
084ee1c6 | 6 | |
d1163651 | 7 | #include <asm/set_memory.h> |
084ee1c6 JS |
8 | #include <asm/pgtable.h> |
9 | #include <asm/realmode.h> | |
18bc7bd5 | 10 | #include <asm/tlbflush.h> |
084ee1c6 | 11 | |
b429dbf6 | 12 | struct real_mode_header *real_mode_header; |
cda846f1 | 13 | u32 *trampoline_cr4_features; |
084ee1c6 | 14 | |
b234e8a0 TG |
15 | /* Hold the pgd entry used on booting additional CPUs */ |
16 | pgd_t trampoline_pgd_entry; | |
17 | ||
5ff3e2c3 AL |
18 | void __init set_real_mode_mem(phys_addr_t mem, size_t size) |
19 | { | |
20 | void *base = __va(mem); | |
21 | ||
22 | real_mode_header = (struct real_mode_header *) base; | |
23 | printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n", | |
24 | base, (unsigned long long)mem, size); | |
25 | } | |
26 | ||
4f7b9226 | 27 | void __init reserve_real_mode(void) |
084ee1c6 JS |
28 | { |
29 | phys_addr_t mem; | |
5ff3e2c3 AL |
30 | size_t size = real_mode_size_needed(); |
31 | ||
32 | if (!size) | |
33 | return; | |
34 | ||
35 | WARN_ON(slab_is_available()); | |
4f7b9226 YL |
36 | |
37 | /* Has to be under 1M so we can execute real-mode AP code. */ | |
38 | mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE); | |
5ff3e2c3 AL |
39 | if (!mem) { |
40 | pr_info("No sub-1M memory is available for the trampoline\n"); | |
41 | return; | |
42 | } | |
4f7b9226 | 43 | |
4f7b9226 | 44 | memblock_reserve(mem, size); |
5ff3e2c3 | 45 | set_real_mode_mem(mem, size); |
4f7b9226 YL |
46 | } |
47 | ||
d0de0f68 | 48 | static void __init setup_real_mode(void) |
4f7b9226 | 49 | { |
084ee1c6 | 50 | u16 real_mode_seg; |
7306006f | 51 | const u32 *rel; |
084ee1c6 | 52 | u32 count; |
b429dbf6 | 53 | unsigned char *base; |
7306006f | 54 | unsigned long phys_base; |
f37240f1 | 55 | struct trampoline_header *trampoline_header; |
b429dbf6 | 56 | size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob); |
f37240f1 JS |
57 | #ifdef CONFIG_X86_64 |
58 | u64 *trampoline_pgd; | |
638d957b | 59 | u64 efer; |
f37240f1 | 60 | #endif |
084ee1c6 | 61 | |
4f7b9226 | 62 | base = (unsigned char *)real_mode_header; |
084ee1c6 | 63 | |
163ea3c8 TL |
64 | /* |
65 | * If SME is active, the trampoline area will need to be in | |
66 | * decrypted memory in order to bring up other processors | |
67 | * successfully. | |
68 | */ | |
69 | set_memory_decrypted((unsigned long)base, size >> PAGE_SHIFT); | |
70 | ||
b429dbf6 | 71 | memcpy(base, real_mode_blob, size); |
084ee1c6 | 72 | |
7306006f PA |
73 | phys_base = __pa(base); |
74 | real_mode_seg = phys_base >> 4; | |
75 | ||
084ee1c6 JS |
76 | rel = (u32 *) real_mode_relocs; |
77 | ||
78 | /* 16-bit segment relocations. */ | |
7306006f PA |
79 | count = *rel++; |
80 | while (count--) { | |
81 | u16 *seg = (u16 *) (base + *rel++); | |
084ee1c6 JS |
82 | *seg = real_mode_seg; |
83 | } | |
84 | ||
85 | /* 32-bit linear relocations. */ | |
7306006f PA |
86 | count = *rel++; |
87 | while (count--) { | |
88 | u32 *ptr = (u32 *) (base + *rel++); | |
89 | *ptr += phys_base; | |
084ee1c6 JS |
90 | } |
91 | ||
f37240f1 JS |
92 | /* Must be perfomed *after* relocation. */ |
93 | trampoline_header = (struct trampoline_header *) | |
94 | __va(real_mode_header->trampoline_header); | |
95 | ||
48927bbb | 96 | #ifdef CONFIG_X86_32 |
fc8d7826 | 97 | trampoline_header->start = __pa_symbol(startup_32_smp); |
f37240f1 | 98 | trampoline_header->gdt_limit = __BOOT_DS + 7; |
fc8d7826 | 99 | trampoline_header->gdt_base = __pa_symbol(boot_gdt); |
48927bbb | 100 | #else |
79603879 PA |
101 | /* |
102 | * Some AMD processors will #GP(0) if EFER.LMA is set in WRMSR | |
103 | * so we need to mask it out. | |
104 | */ | |
638d957b PA |
105 | rdmsrl(MSR_EFER, efer); |
106 | trampoline_header->efer = efer & ~EFER_LMA; | |
cda846f1 | 107 | |
f37240f1 | 108 | trampoline_header->start = (u64) secondary_startup_64; |
cda846f1 | 109 | trampoline_cr4_features = &trampoline_header->cr4; |
18bc7bd5 | 110 | *trampoline_cr4_features = mmu_cr4_features; |
cda846f1 | 111 | |
46d010e0 TL |
112 | trampoline_header->flags = 0; |
113 | if (sme_active()) | |
114 | trampoline_header->flags |= TH_FLAGS_SME_ACTIVE; | |
115 | ||
f37240f1 | 116 | trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd); |
b234e8a0 | 117 | trampoline_pgd[0] = trampoline_pgd_entry.pgd; |
65ade2f8 | 118 | trampoline_pgd[511] = init_top_pgt[511].pgd; |
48927bbb | 119 | #endif |
084ee1c6 JS |
120 | } |
121 | ||
122 | /* | |
4f7b9226 | 123 | * reserve_real_mode() gets called very early, to guarantee the |
231b3642 | 124 | * availability of low memory. This is before the proper kernel page |
084ee1c6 | 125 | * tables are set up, so we cannot set page permissions in that |
231b3642 YL |
126 | * function. Also trampoline code will be executed by APs so we |
127 | * need to mark it executable at do_pre_smp_initcalls() at least, | |
128 | * thus run it as a early_initcall(). | |
084ee1c6 | 129 | */ |
d0de0f68 | 130 | static void __init set_real_mode_permissions(void) |
084ee1c6 | 131 | { |
b429dbf6 JS |
132 | unsigned char *base = (unsigned char *) real_mode_header; |
133 | size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob); | |
084ee1c6 | 134 | |
f156ffc4 | 135 | size_t ro_size = |
b429dbf6 JS |
136 | PAGE_ALIGN(real_mode_header->ro_end) - |
137 | __pa(base); | |
f156ffc4 JS |
138 | |
139 | size_t text_size = | |
b429dbf6 JS |
140 | PAGE_ALIGN(real_mode_header->ro_end) - |
141 | real_mode_header->text_start; | |
f156ffc4 JS |
142 | |
143 | unsigned long text_start = | |
b429dbf6 | 144 | (unsigned long) __va(real_mode_header->text_start); |
f156ffc4 | 145 | |
b429dbf6 JS |
146 | set_memory_nx((unsigned long) base, size >> PAGE_SHIFT); |
147 | set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT); | |
f156ffc4 | 148 | set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT); |
d0de0f68 AL |
149 | } |
150 | ||
151 | static int __init init_real_mode(void) | |
152 | { | |
153 | if (!real_mode_header) | |
154 | panic("Real mode trampoline was not allocated"); | |
155 | ||
156 | setup_real_mode(); | |
157 | set_real_mode_permissions(); | |
f156ffc4 | 158 | |
084ee1c6 JS |
159 | return 0; |
160 | } | |
d0de0f68 | 161 | early_initcall(init_real_mode); |