[deliverable/linux.git] / arch / x86 / kernel / efi_32.c

/*
 * Extensible Firmware Interface
 *
 * Based on Extensible Firmware Interface Specification version 1.0
 *
 * Copyright (C) 1999 VA Linux Systems
 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
 * Copyright (C) 1999-2002 Hewlett-Packard Co.
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 *	Stephane Eranian <eranian@hpl.hp.com>
 *
 * All EFI Runtime Services are not implemented yet as EFI only
 * supports physical mode addressing on SoftSDV. This is to be fixed
 * in a future version.  --drummond 1999-07-20
 *
 * Implemented EFI runtime services and virtual mode calls.  --davidm
 *
 * Goutham Rao: <goutham.rao@intel.com>
 *	Skip non-WB memory and ignore empty memory ranges.
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/efi.h>

#include <asm/io.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/efi.h>

/*
 * To make EFI call EFI runtime service in physical addressing mode we need
 * prelog/epilog before/after the invocation to disable interrupt, to
 * claim EFI runtime service handler exclusively and to duplicate a memory in
 * low memory space say 0 - 3G.
 */

static unsigned long efi_rt_eflags;
static pgd_t efi_bak_pg_dir_pointer[2];

void efi_call_phys_prelog(void)
{
	unsigned long cr4;
	unsigned long temp;
	struct desc_ptr gdt_descr;

	local_irq_save(efi_rt_eflags);

	/*
	 * If I don't have PAE, I should just duplicate two entries in page
	 * directory. If I have PAE, I just need to duplicate one entry in
	 * page directory.
	 */
	cr4 = read_cr4_safe();

	if (cr4 & X86_CR4_PAE) {
		efi_bak_pg_dir_pointer[0].pgd =
		    swapper_pg_dir[pgd_index(0)].pgd;
		swapper_pg_dir[0].pgd =
		    swapper_pg_dir[pgd_index(PAGE_OFFSET)].pgd;
	} else {
		efi_bak_pg_dir_pointer[0].pgd =
		    swapper_pg_dir[pgd_index(0)].pgd;
		efi_bak_pg_dir_pointer[1].pgd =
		    swapper_pg_dir[pgd_index(0x400000)].pgd;
		swapper_pg_dir[pgd_index(0)].pgd =
		    swapper_pg_dir[pgd_index(PAGE_OFFSET)].pgd;
		temp = PAGE_OFFSET + 0x400000;
		swapper_pg_dir[pgd_index(0x400000)].pgd =
		    swapper_pg_dir[pgd_index(temp)].pgd;
	}

	/*
	 * After the lock is released, the original page table is restored.
	 */
	__flush_tlb_all();

	gdt_descr.address = __pa(get_cpu_gdt_table(0));
	gdt_descr.size = GDT_SIZE - 1;
	load_gdt(&gdt_descr);
}

void efi_call_phys_epilog(void)
{
	unsigned long cr4;
	struct desc_ptr gdt_descr;

	gdt_descr.address = (unsigned long)get_cpu_gdt_table(0);
	gdt_descr.size = GDT_SIZE - 1;
	load_gdt(&gdt_descr);

	cr4 = read_cr4_safe();

	if (cr4 & X86_CR4_PAE) {
		swapper_pg_dir[pgd_index(0)].pgd =
		    efi_bak_pg_dir_pointer[0].pgd;
	} else {
		swapper_pg_dir[pgd_index(0)].pgd =
		    efi_bak_pg_dir_pointer[0].pgd;
		swapper_pg_dir[pgd_index(0x400000)].pgd =
		    efi_bak_pg_dir_pointer[1].pgd;
	}

	/*
	 * After the lock is released, the original page table is restored.
	 */
	__flush_tlb_all();

	local_irq_restore(efi_rt_eflags);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Extensible Firmware Interface
	3	*
	4	* Based on Extensible Firmware Interface Specification version 1.0
	5	*
	6	* Copyright (C) 1999 VA Linux Systems
	7	* Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
	8	* Copyright (C) 1999-2002 Hewlett-Packard Co.
	9	* David Mosberger-Tang <davidm@hpl.hp.com>
	10	* Stephane Eranian <eranian@hpl.hp.com>
	11	*
	12	* All EFI Runtime Services are not implemented yet as EFI only
	13	* supports physical mode addressing on SoftSDV. This is to be fixed
	14	* in a future version. --drummond 1999-07-20
	15	*
	16	* Implemented EFI runtime services and virtual mode calls. --davidm
	17	*
	18	* Goutham Rao: <goutham.rao@intel.com>
	19	* Skip non-WB memory and ignore empty memory ranges.
	20	*/
	21
1da177e4	22	#include <linux/kernel.h>
1da177e4	23	#include <linux/types.h>
1da177e4	24	#include <linux/ioport.h>
1da177e4 LT	25	#include <linux/efi.h>
1da177e4 LT	26
1da177e4 LT	27	#include <asm/io.h>
	28	#include <asm/page.h>
	29	#include <asm/pgtable.h>
1da177e4	30	#include <asm/tlbflush.h>
cc7e73f3	31	#include <asm/efi.h>
1da177e4	32
1da177e4 LT	33	/*
	34	* To make EFI call EFI runtime service in physical addressing mode we need
	35	* prelog/epilog before/after the invocation to disable interrupt, to
	36	* claim EFI runtime service handler exclusively and to duplicate a memory in
	37	* low memory space say 0 - 3G.
	38	*/
	39
	40	static unsigned long efi_rt_eflags;
1da177e4 LT	41	static pgd_t efi_bak_pg_dir_pointer[2];
1da177e4 LT	42
8b2cb7a8	43	void efi_call_phys_prelog(void)
1da177e4 LT	44	{
	45	unsigned long cr4;
	46	unsigned long temp;
6b68f01b	47	struct desc_ptr gdt_descr;
1da177e4	48
1da177e4 LT	49	local_irq_save(efi_rt_eflags);
	50
	51	/*
216705d2 HD	52	* If I don't have PAE, I should just duplicate two entries in page
216705d2 HD	53	* directory. If I have PAE, I just need to duplicate one entry in
1da177e4 LT	54	* page directory.
1da177e4 LT	55	*/
e532c06f	56	cr4 = read_cr4_safe();
1da177e4	57
216705d2	58	if (cr4 & X86_CR4_PAE) {
1da177e4 LT	59	efi_bak_pg_dir_pointer[0].pgd =
	60	swapper_pg_dir[pgd_index(0)].pgd;
	61	swapper_pg_dir[0].pgd =
	62	swapper_pg_dir[pgd_index(PAGE_OFFSET)].pgd;
	63	} else {
	64	efi_bak_pg_dir_pointer[0].pgd =
	65	swapper_pg_dir[pgd_index(0)].pgd;
	66	efi_bak_pg_dir_pointer[1].pgd =
	67	swapper_pg_dir[pgd_index(0x400000)].pgd;
	68	swapper_pg_dir[pgd_index(0)].pgd =
	69	swapper_pg_dir[pgd_index(PAGE_OFFSET)].pgd;
	70	temp = PAGE_OFFSET + 0x400000;
	71	swapper_pg_dir[pgd_index(0x400000)].pgd =
	72	swapper_pg_dir[pgd_index(temp)].pgd;
	73	}
	74
	75	/*
	76	* After the lock is released, the original page table is restored.
	77	*/
8b2cb7a8	78	__flush_tlb_all();
1da177e4	79
4fbb5968 RR	80	gdt_descr.address = __pa(get_cpu_gdt_table(0));
	81	gdt_descr.size = GDT_SIZE - 1;
	82	load_gdt(&gdt_descr);
1da177e4 LT	83	}
1da177e4 LT	84
8b2cb7a8	85	void efi_call_phys_epilog(void)
1da177e4 LT	86	{
1da177e4 LT	87	unsigned long cr4;
6b68f01b	88	struct desc_ptr gdt_descr;
1da177e4	89
4fbb5968 RR	90	gdt_descr.address = (unsigned long)get_cpu_gdt_table(0);
	91	gdt_descr.size = GDT_SIZE - 1;
	92	load_gdt(&gdt_descr);
2b932f6c	93
e532c06f	94	cr4 = read_cr4_safe();
1da177e4	95
216705d2	96	if (cr4 & X86_CR4_PAE) {
1da177e4 LT	97	swapper_pg_dir[pgd_index(0)].pgd =
	98	efi_bak_pg_dir_pointer[0].pgd;
	99	} else {
	100	swapper_pg_dir[pgd_index(0)].pgd =
	101	efi_bak_pg_dir_pointer[0].pgd;
	102	swapper_pg_dir[pgd_index(0x400000)].pgd =
	103	efi_bak_pg_dir_pointer[1].pgd;
	104	}
	105
	106	/*
	107	* After the lock is released, the original page table is restored.
	108	*/
8b2cb7a8	109	__flush_tlb_all();
1da177e4 LT	110
1da177e4 LT	111	local_irq_restore(efi_rt_eflags);
1da177e4	112	}