mirror of https://gitee.com/openkylin/linux.git
43 lines
1.2 KiB
C
43 lines
1.2 KiB
C
#include <linux/io.h>
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#include <linux/memblock.h>
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#include <asm/trampoline.h>
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#include <asm/cacheflush.h>
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#include <asm/pgtable.h>
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unsigned char *x86_trampoline_base;
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void __init setup_trampolines(void)
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{
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phys_addr_t mem;
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size_t size = PAGE_ALIGN(x86_trampoline_end - x86_trampoline_start);
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/* Has to be in very low memory so we can execute real-mode AP code. */
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mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
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if (!mem)
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panic("Cannot allocate trampoline\n");
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x86_trampoline_base = __va(mem);
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memblock_reserve(mem, size);
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printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
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x86_trampoline_base, (unsigned long long)mem, size);
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memcpy(x86_trampoline_base, x86_trampoline_start, size);
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}
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/*
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* setup_trampolines() gets called very early, to guarantee the
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* availability of low memory. This is before the proper kernel page
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* tables are set up, so we cannot set page permissions in that
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* function. Thus, we use an arch_initcall instead.
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*/
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static int __init configure_trampolines(void)
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{
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size_t size = PAGE_ALIGN(x86_trampoline_end - x86_trampoline_start);
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set_memory_x((unsigned long)x86_trampoline_base, size >> PAGE_SHIFT);
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return 0;
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}
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arch_initcall(configure_trampolines);
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