1#include <linux/io.h>
 2#include <linux/memblock.h>
 3
 4#include <asm/trampoline.h>
 5#include <asm/cacheflush.h>
 6#include <asm/pgtable.h>
 7
 8unsigned char *x86_trampoline_base;
 9
10void __init setup_trampolines(void)
11{
12	phys_addr_t mem;
13	size_t size = PAGE_ALIGN(x86_trampoline_end - x86_trampoline_start);
14
15	/* Has to be in very low memory so we can execute real-mode AP code. */
16	mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
17	if (mem == MEMBLOCK_ERROR)
18		panic("Cannot allocate trampoline\n");
19
20	x86_trampoline_base = __va(mem);
21	memblock_x86_reserve_range(mem, mem + size, "TRAMPOLINE");
22
23	printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
24	       x86_trampoline_base, (unsigned long long)mem, size);
25
26	memcpy(x86_trampoline_base, x86_trampoline_start, size);
27}
28
29/*
30 * setup_trampolines() gets called very early, to guarantee the
31 * availability of low memory.  This is before the proper kernel page
32 * tables are set up, so we cannot set page permissions in that
33 * function.  Thus, we use an arch_initcall instead.
34 */
35static int __init configure_trampolines(void)
36{
37	size_t size = PAGE_ALIGN(x86_trampoline_end - x86_trampoline_start);
38
39	set_memory_x((unsigned long)x86_trampoline_base, size >> PAGE_SHIFT);
40	return 0;
41}
42arch_initcall(configure_trampolines);