[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/init.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <linux/time.h>
#include <linux/spinlock.h>
#include <linux/bootmem.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/efi.h>
#include <linux/kexec.h>

#include <asm/setup.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/desc.h>
#include <asm/tlbflush.h>

#define PFX 		"EFI: "

/*
 * 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 DEFINE_SPINLOCK(efi_rt_lock);
static pgd_t efi_bak_pg_dir_pointer[2];

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

	spin_lock(&efi_rt_lock);
	local_irq_save(efi_rt_eflags);

	/*
	 * If I don't have PSE, I should just duplicate two entries in page
	 * directory. If I have PSE, I just need to duplicate one entry in
	 * page directory.
	 */
	cr4 = read_cr4();

	if (cr4 & X86_CR4_PSE) {
		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.
	 */
	local_flush_tlb();

	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) __releases(efi_rt_lock)
{
	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();

	if (cr4 & X86_CR4_PSE) {
		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.
	 */
	local_flush_tlb();

	local_irq_restore(efi_rt_eflags);
	spin_unlock(&efi_rt_lock);
}

/*
 * We need to map the EFI memory map again after paging_init().
 */
void __init efi_map_memmap(void)
{
	memmap.map = NULL;

	memmap.map = bt_ioremap((unsigned long) memmap.phys_map,
			(memmap.nr_map * memmap.desc_size));
	if (memmap.map == NULL)
		printk(KERN_ERR PFX "Could not remap the EFI memmap!\n");

	memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
}
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 LT	22	#include <linux/kernel.h>
	23	#include <linux/init.h>
	24	#include <linux/mm.h>
	25	#include <linux/types.h>
	26	#include <linux/time.h>
	27	#include <linux/spinlock.h>
	28	#include <linux/bootmem.h>
	29	#include <linux/ioport.h>
	30	#include <linux/module.h>
	31	#include <linux/efi.h>
1bc3b91a	32	#include <linux/kexec.h>
1da177e4 LT	33
	34	#include <asm/setup.h>
	35	#include <asm/io.h>
	36	#include <asm/page.h>
	37	#include <asm/pgtable.h>
	38	#include <asm/processor.h>
	39	#include <asm/desc.h>
	40	#include <asm/tlbflush.h>
	41
1da177e4 LT	42	#define PFX "EFI: "
1da177e4 LT	43
1da177e4 LT	44	/*
	45	* To make EFI call EFI runtime service in physical addressing mode we need
	46	* prelog/epilog before/after the invocation to disable interrupt, to
	47	* claim EFI runtime service handler exclusively and to duplicate a memory in
	48	* low memory space say 0 - 3G.
	49	*/
	50
	51	static unsigned long efi_rt_eflags;
	52	static DEFINE_SPINLOCK(efi_rt_lock);
	53	static pgd_t efi_bak_pg_dir_pointer[2];
	54
e429795c	55	void efi_call_phys_prelog(void) __acquires(efi_rt_lock)
1da177e4 LT	56	{
	57	unsigned long cr4;
	58	unsigned long temp;
6b68f01b	59	struct desc_ptr gdt_descr;
1da177e4 LT	60
	61	spin_lock(&efi_rt_lock);
	62	local_irq_save(efi_rt_eflags);
	63
	64	/*
	65	* If I don't have PSE, I should just duplicate two entries in page
	66	* directory. If I have PSE, I just need to duplicate one entry in
	67	* page directory.
	68	*/
4bb0d3ec	69	cr4 = read_cr4();
1da177e4 LT	70
	71	if (cr4 & X86_CR4_PSE) {
	72	efi_bak_pg_dir_pointer[0].pgd =
	73	swapper_pg_dir[pgd_index(0)].pgd;
	74	swapper_pg_dir[0].pgd =
	75	swapper_pg_dir[pgd_index(PAGE_OFFSET)].pgd;
	76	} else {
	77	efi_bak_pg_dir_pointer[0].pgd =
	78	swapper_pg_dir[pgd_index(0)].pgd;
	79	efi_bak_pg_dir_pointer[1].pgd =
	80	swapper_pg_dir[pgd_index(0x400000)].pgd;
	81	swapper_pg_dir[pgd_index(0)].pgd =
	82	swapper_pg_dir[pgd_index(PAGE_OFFSET)].pgd;
	83	temp = PAGE_OFFSET + 0x400000;
	84	swapper_pg_dir[pgd_index(0x400000)].pgd =
	85	swapper_pg_dir[pgd_index(temp)].pgd;
	86	}
	87
	88	/*
	89	* After the lock is released, the original page table is restored.
	90	*/
	91	local_flush_tlb();
	92
4fbb5968 RR	93	gdt_descr.address = __pa(get_cpu_gdt_table(0));
	94	gdt_descr.size = GDT_SIZE - 1;
	95	load_gdt(&gdt_descr);
1da177e4 LT	96	}
1da177e4 LT	97
e429795c	98	void efi_call_phys_epilog(void) __releases(efi_rt_lock)
1da177e4 LT	99	{
1da177e4 LT	100	unsigned long cr4;
6b68f01b	101	struct desc_ptr gdt_descr;
1da177e4	102
4fbb5968 RR	103	gdt_descr.address = (unsigned long)get_cpu_gdt_table(0);
	104	gdt_descr.size = GDT_SIZE - 1;
	105	load_gdt(&gdt_descr);
2b932f6c	106
4bb0d3ec	107	cr4 = read_cr4();
1da177e4 LT	108
	109	if (cr4 & X86_CR4_PSE) {
	110	swapper_pg_dir[pgd_index(0)].pgd =
	111	efi_bak_pg_dir_pointer[0].pgd;
	112	} else {
	113	swapper_pg_dir[pgd_index(0)].pgd =
	114	efi_bak_pg_dir_pointer[0].pgd;
	115	swapper_pg_dir[pgd_index(0x400000)].pgd =
	116	efi_bak_pg_dir_pointer[1].pgd;
	117	}
	118
	119	/*
	120	* After the lock is released, the original page table is restored.
	121	*/
	122	local_flush_tlb();
	123
	124	local_irq_restore(efi_rt_eflags);
	125	spin_unlock(&efi_rt_lock);
	126	}
	127
1da177e4 LT	128	/*
	129	* We need to map the EFI memory map again after paging_init().
	130	*/
	131	void __init efi_map_memmap(void)
	132	{
	133	memmap.map = NULL;
	134
7ae65fd3 MT	135	memmap.map = bt_ioremap((unsigned long) memmap.phys_map,
7ae65fd3 MT	136	(memmap.nr_map * memmap.desc_size));
1da177e4 LT	137	if (memmap.map == NULL)
1da177e4 LT	138	printk(KERN_ERR PFX "Could not remap the EFI memmap!\n");
7ae65fd3 MT	139
7ae65fd3 MT	140	memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
1da177e4	141	}