.. | .. |
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5 | 5 | #include "pgtable.h" |
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6 | 6 | #include "../string.h" |
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7 | 7 | |
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8 | | -/* |
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9 | | - * __force_order is used by special_insns.h asm code to force instruction |
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10 | | - * serialization. |
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11 | | - * |
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12 | | - * It is not referenced from the code, but GCC < 5 with -fPIE would fail |
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13 | | - * due to an undefined symbol. Define it to make these ancient GCCs work. |
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14 | | - */ |
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15 | | -unsigned long __force_order; |
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16 | | - |
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17 | 8 | #define BIOS_START_MIN 0x20000U /* 128K, less than this is insane */ |
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18 | 9 | #define BIOS_START_MAX 0x9f000U /* 640K, absolute maximum */ |
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| 10 | + |
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| 11 | +#ifdef CONFIG_X86_5LEVEL |
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| 12 | +/* __pgtable_l5_enabled needs to be in .data to avoid being cleared along with .bss */ |
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| 13 | +unsigned int __section(".data") __pgtable_l5_enabled; |
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| 14 | +unsigned int __section(".data") pgdir_shift = 39; |
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| 15 | +unsigned int __section(".data") ptrs_per_p4d = 1; |
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| 16 | +#endif |
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19 | 17 | |
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20 | 18 | struct paging_config { |
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21 | 19 | unsigned long trampoline_start; |
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.. | .. |
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32 | 30 | * Avoid putting the pointer into .bss as it will be cleared between |
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33 | 31 | * paging_prepare() and extract_kernel(). |
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34 | 32 | */ |
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35 | | -unsigned long *trampoline_32bit __section(.data); |
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| 33 | +unsigned long *trampoline_32bit __section(".data"); |
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36 | 34 | |
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37 | 35 | extern struct boot_params *boot_params; |
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38 | 36 | int cmdline_find_option_bool(const char *option); |
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.. | .. |
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40 | 38 | static unsigned long find_trampoline_placement(void) |
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41 | 39 | { |
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42 | 40 | unsigned long bios_start = 0, ebda_start = 0; |
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43 | | - unsigned long trampoline_start; |
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44 | 41 | struct boot_e820_entry *entry; |
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45 | 42 | char *signature; |
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46 | 43 | int i; |
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.. | .. |
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208 | 205 | |
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209 | 206 | /* Restore trampoline memory */ |
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210 | 207 | memcpy(trampoline_32bit, trampoline_save, TRAMPOLINE_32BIT_SIZE); |
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| 208 | + |
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| 209 | + /* Initialize variables for 5-level paging */ |
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| 210 | +#ifdef CONFIG_X86_5LEVEL |
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| 211 | + if (__read_cr4() & X86_CR4_LA57) { |
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| 212 | + __pgtable_l5_enabled = 1; |
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| 213 | + pgdir_shift = 48; |
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| 214 | + ptrs_per_p4d = 512; |
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| 215 | + } |
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| 216 | +#endif |
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211 | 217 | } |
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