trampoline.c 989 Bytes
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#include <linux/io.h>

#include <asm/trampoline.h>
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#include <asm/e820.h>
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#if defined(CONFIG_X86_64) && defined(CONFIG_ACPI_SLEEP)
#define __trampinit
#define __trampinitdata
#else
#define __trampinit __cpuinit
#define __trampinitdata __cpuinitdata
#endif

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/* ready for x86_64 and x86 */
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unsigned char *__trampinitdata trampoline_base;
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void __init reserve_trampoline_memory(void)
{
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	unsigned long mem;

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	/* Has to be in very low memory so we can execute real-mode AP code. */
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	mem = find_e820_area(0, 1<<20, TRAMPOLINE_SIZE, PAGE_SIZE);
	if (mem == -1L)
		panic("Cannot allocate trampoline\n");

	trampoline_base = __va(mem);
	reserve_early(mem, mem + TRAMPOLINE_SIZE, "TRAMPOLINE");
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}

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/*
 * Currently trivial. Write the real->protected mode
 * bootstrap into the page concerned. The caller
 * has made sure it's suitably aligned.
 */
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unsigned long __trampinit setup_trampoline(void)
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{
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	memcpy(trampoline_base, trampoline_data, TRAMPOLINE_SIZE);
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	return virt_to_phys(trampoline_base);
}