[linux-2.6-block.git] / arch / x86 / kernel / realmode.c

#include <linux/io.h>
#include <linux/memblock.h>

#include <asm/cacheflush.h>
#include <asm/pgtable.h>
#include <asm/realmode.h>

struct real_mode_header *real_mode_header;

void __init setup_real_mode(void)
{
	phys_addr_t mem;
	u16 real_mode_seg;
	u32 *rel;
	u32 count;
	u32 *ptr;
	u16 *seg;
	int i;
	unsigned char *base;
	struct trampoline_header *trampoline_header;
	size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
#ifdef CONFIG_X86_64
	u64 *trampoline_pgd;
#endif

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

	base = __va(mem);
	memblock_reserve(mem, size);
	real_mode_header = (struct real_mode_header *) base;
	printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
	       base, (unsigned long long)mem, size);

	memcpy(base, real_mode_blob, size);

	real_mode_seg = __pa(base) >> 4;
	rel = (u32 *) real_mode_relocs;

	/* 16-bit segment relocations. */
	count = rel[0];
	rel = &rel[1];
	for (i = 0; i < count; i++) {
		seg = (u16 *) (base + rel[i]);
		*seg = real_mode_seg;
	}

	/* 32-bit linear relocations. */
	count = rel[i];
	rel =  &rel[i + 1];
	for (i = 0; i < count; i++) {
		ptr = (u32 *) (base + rel[i]);
		*ptr += __pa(base);
	}

	/* Must be perfomed *after* relocation. */
	trampoline_header = (struct trampoline_header *)
		__va(real_mode_header->trampoline_header);

#ifdef CONFIG_X86_32
	trampoline_header->start = __pa(startup_32_smp);
	trampoline_header->gdt_limit = __BOOT_DS + 7;
	trampoline_header->gdt_base = __pa(boot_gdt);
#else
	trampoline_header->start = (u64) secondary_startup_64;
	trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd);
	trampoline_pgd[0] = __pa(level3_ident_pgt) + _KERNPG_TABLE;
	trampoline_pgd[511] = __pa(level3_kernel_pgt) + _KERNPG_TABLE;
#endif
}

/*
 * set_real_mode_permissions() gets called very early, to guarantee the
 * availability of low memory.  This is before the proper kernel page
 * tables are set up, so we cannot set page permissions in that
 * function.  Thus, we use an arch_initcall instead.
 */
static int __init set_real_mode_permissions(void)
{
	unsigned char *base = (unsigned char *) real_mode_header;
	size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);

	size_t ro_size =
		PAGE_ALIGN(real_mode_header->ro_end) -
		__pa(base);

	size_t text_size =
		PAGE_ALIGN(real_mode_header->ro_end) -
		real_mode_header->text_start;

	unsigned long text_start =
		(unsigned long) __va(real_mode_header->text_start);

	set_memory_nx((unsigned long) base, size >> PAGE_SHIFT);
	set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT);
	set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT);

	return 0;
}

arch_initcall(set_real_mode_permissions);
Commit	Line	Data
084ee1c6 JS	1	#include <linux/io.h>
	2	#include <linux/memblock.h>
	3
	4	#include <asm/cacheflush.h>
	5	#include <asm/pgtable.h>
	6	#include <asm/realmode.h>
	7
b429dbf6	8	struct real_mode_header *real_mode_header;
084ee1c6 JS	9
	10	void __init setup_real_mode(void)
	11	{
	12	phys_addr_t mem;
	13	u16 real_mode_seg;
	14	u32 *rel;
	15	u32 count;
	16	u32 *ptr;
	17	u16 *seg;
	18	int i;
b429dbf6	19	unsigned char *base;
f37240f1	20	struct trampoline_header *trampoline_header;
b429dbf6	21	size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
f37240f1 JS	22	#ifdef CONFIG_X86_64
	23	u64 *trampoline_pgd;
	24	#endif
084ee1c6 JS	25
	26	/* Has to be in very low memory so we can execute real-mode AP code. */
	27	mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
	28	if (!mem)
	29	panic("Cannot allocate trampoline\n");
	30
b429dbf6	31	base = __va(mem);
084ee1c6	32	memblock_reserve(mem, size);
b429dbf6	33	real_mode_header = (struct real_mode_header *) base;
084ee1c6	34	printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
b429dbf6	35	base, (unsigned long long)mem, size);
084ee1c6	36
b429dbf6	37	memcpy(base, real_mode_blob, size);
084ee1c6	38
b429dbf6	39	real_mode_seg = __pa(base) >> 4;
084ee1c6 JS	40	rel = (u32 *) real_mode_relocs;
	41
	42	/* 16-bit segment relocations. */
	43	count = rel[0];
	44	rel = &rel[1];
	45	for (i = 0; i < count; i++) {
b429dbf6	46	seg = (u16 *) (base + rel[i]);
084ee1c6 JS	47	*seg = real_mode_seg;
	48	}
	49
	50	/* 32-bit linear relocations. */
	51	count = rel[i];
	52	rel = &rel[i + 1];
	53	for (i = 0; i < count; i++) {
b429dbf6 JS	54	ptr = (u32 *) (base + rel[i]);
b429dbf6 JS	55	*ptr += __pa(base);
084ee1c6 JS	56	}
084ee1c6 JS	57
f37240f1 JS	58	/* Must be perfomed after relocation. */
	59	trampoline_header = (struct trampoline_header *)
	60	__va(real_mode_header->trampoline_header);
	61
48927bbb	62	#ifdef CONFIG_X86_32
f37240f1 JS	63	trampoline_header->start = __pa(startup_32_smp);
	64	trampoline_header->gdt_limit = __BOOT_DS + 7;
	65	trampoline_header->gdt_base = __pa(boot_gdt);
48927bbb	66	#else
f37240f1 JS	67	trampoline_header->start = (u64) secondary_startup_64;
	68	trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd);
	69	trampoline_pgd[0] = __pa(level3_ident_pgt) + _KERNPG_TABLE;
	70	trampoline_pgd[511] = __pa(level3_kernel_pgt) + _KERNPG_TABLE;
48927bbb	71	#endif
084ee1c6 JS	72	}
	73
	74	/*
	75	* set_real_mode_permissions() gets called very early, to guarantee the
	76	* availability of low memory. This is before the proper kernel page
	77	* tables are set up, so we cannot set page permissions in that
	78	* function. Thus, we use an arch_initcall instead.
	79	*/
	80	static int __init set_real_mode_permissions(void)
	81	{
b429dbf6 JS	82	unsigned char base = (unsigned char ) real_mode_header;
b429dbf6 JS	83	size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
084ee1c6	84
f156ffc4	85	size_t ro_size =
b429dbf6 JS	86	PAGE_ALIGN(real_mode_header->ro_end) -
b429dbf6 JS	87	__pa(base);
f156ffc4 JS	88
f156ffc4 JS	89	size_t text_size =
b429dbf6 JS	90	PAGE_ALIGN(real_mode_header->ro_end) -
b429dbf6 JS	91	real_mode_header->text_start;
f156ffc4 JS	92
f156ffc4 JS	93	unsigned long text_start =
b429dbf6	94	(unsigned long) __va(real_mode_header->text_start);
f156ffc4	95
b429dbf6 JS	96	set_memory_nx((unsigned long) base, size >> PAGE_SHIFT);
b429dbf6 JS	97	set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT);
f156ffc4 JS	98	set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT);
f156ffc4 JS	99
084ee1c6 JS	100	return 0;
	101	}
	102
	103	arch_initcall(set_real_mode_permissions);