linux/arch/x86/kernel/trampoline.c

40 lines
989 B
C

#include <linux/io.h>
#include <asm/trampoline.h>
#include <asm/e820.h>
#if defined(CONFIG_X86_64) && defined(CONFIG_ACPI_SLEEP)
#define __trampinit
#define __trampinitdata
#else
#define __trampinit __cpuinit
#define __trampinitdata __cpuinitdata
#endif
/* ready for x86_64 and x86 */
unsigned char *__trampinitdata trampoline_base;
void __init reserve_trampoline_memory(void)
{
unsigned long mem;
/* Has to be in very low memory so we can execute real-mode AP code. */
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");
}
/*
* Currently trivial. Write the real->protected mode
* bootstrap into the page concerned. The caller
* has made sure it's suitably aligned.
*/
unsigned long __trampinit setup_trampoline(void)
{
memcpy(trampoline_base, trampoline_data, TRAMPOLINE_SIZE);
return virt_to_phys(trampoline_base);
}