f37240f16b
Added header for trampoline code that can be used to supply input data to it. This makes interface between real mode code and kernel cleaner and simpler. Replaced two confusing pointers to level4 pgt in trampoline_64.S with a single pointer to the beginning of the page table. Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com> Link: http://lkml.kernel.org/r/1336501366-28617-21-git-send-email-jarkko.sakkinen@intel.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
104 lines
2.8 KiB
C
104 lines
2.8 KiB
C
#include <linux/io.h>
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#include <linux/memblock.h>
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#include <asm/cacheflush.h>
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#include <asm/pgtable.h>
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#include <asm/realmode.h>
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struct real_mode_header *real_mode_header;
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void __init setup_real_mode(void)
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{
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phys_addr_t mem;
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u16 real_mode_seg;
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u32 *rel;
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u32 count;
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u32 *ptr;
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u16 *seg;
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int i;
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unsigned char *base;
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struct trampoline_header *trampoline_header;
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size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
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#ifdef CONFIG_X86_64
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u64 *trampoline_pgd;
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#endif
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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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base = __va(mem);
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memblock_reserve(mem, size);
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real_mode_header = (struct real_mode_header *) base;
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printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
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base, (unsigned long long)mem, size);
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memcpy(base, real_mode_blob, size);
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real_mode_seg = __pa(base) >> 4;
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rel = (u32 *) real_mode_relocs;
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/* 16-bit segment relocations. */
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count = rel[0];
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rel = &rel[1];
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for (i = 0; i < count; i++) {
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seg = (u16 *) (base + rel[i]);
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*seg = real_mode_seg;
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}
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/* 32-bit linear relocations. */
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count = rel[i];
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rel = &rel[i + 1];
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for (i = 0; i < count; i++) {
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ptr = (u32 *) (base + rel[i]);
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*ptr += __pa(base);
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}
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/* Must be perfomed *after* relocation. */
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trampoline_header = (struct trampoline_header *)
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__va(real_mode_header->trampoline_header);
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#ifdef CONFIG_X86_32
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trampoline_header->start = __pa(startup_32_smp);
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trampoline_header->gdt_limit = __BOOT_DS + 7;
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trampoline_header->gdt_base = __pa(boot_gdt);
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#else
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trampoline_header->start = (u64) secondary_startup_64;
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trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd);
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trampoline_pgd[0] = __pa(level3_ident_pgt) + _KERNPG_TABLE;
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trampoline_pgd[511] = __pa(level3_kernel_pgt) + _KERNPG_TABLE;
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#endif
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}
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/*
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* set_real_mode_permissions() 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 set_real_mode_permissions(void)
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{
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unsigned char *base = (unsigned char *) real_mode_header;
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size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
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size_t ro_size =
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PAGE_ALIGN(real_mode_header->ro_end) -
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__pa(base);
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size_t text_size =
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PAGE_ALIGN(real_mode_header->ro_end) -
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real_mode_header->text_start;
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unsigned long text_start =
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(unsigned long) __va(real_mode_header->text_start);
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set_memory_nx((unsigned long) base, size >> PAGE_SHIFT);
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set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT);
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set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT);
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return 0;
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}
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arch_initcall(set_real_mode_permissions);
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