efi.c

linux-2.6.15.6

/*
 * Extensible Firmware Interface
 *
 * Based on Extensible Firmware Interface Specification version 1.0
 *
 * Copyright (C) 1999 VA Linux Systems
 * Copyright (C) 1999 Walt Drummond <[e-mail]>
 * Copyright (C) 1999-2002 Hewlett-Packard Co.
 *	David Mosberger-Tang <[e-mail]>
 *	Stephane Eranian <[e-mail]>
 *
 * 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: <[e-mail]>
 *	Skip non-WB memory and ignore empty memory ranges.
 */

#include <linux/config.h>
#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 EFI_DEBUG	0
#define PFX 		"EFI: "

extern efi_status_t asmlinkage efi_call_phys(void *, ...);

struct efi efi;
EXPORT_SYMBOL(efi);
static struct efi efi_phys;
struct efi_memory_map memmap;

/*
 * We require an early boot_ioremap mapping mechanism initially
 */
extern void * boot_ioremap(unsigned long, unsigned long);

/*
 * 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];

static void efi_call_phys_prelog(void)
{
	unsigned long cr4;
	unsigned long temp;

	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();

	cpu_gdt_descr[0].address = __pa(cpu_gdt_descr[0].address);
	load_gdt((struct Xgt_desc_struct *) __pa(&cpu_gdt_descr[0]));
}

static void efi_call_phys_epilog(void)
{
	unsigned long cr4;

	cpu_gdt_descr[0].address =
		(unsigned long) __va(cpu_gdt_descr[0].address);
	load_gdt(&cpu_gdt_descr[0]);
	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);
}

static efi_status_t
phys_efi_set_virtual_address_map(unsigned long memory_map_size,
				 unsigned long descriptor_size,
				 u32 descriptor_version,
				 efi_memory_desc_t *virtual_map)
{
	efi_status_t status;

	efi_call_phys_prelog();
	status = efi_call_phys(efi_phys.set_virtual_address_map,
				     memory_map_size, descriptor_size,
				     descriptor_version, virtual_map);
	efi_call_phys_epilog();
	return status;
}

static efi_status_t
phys_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
{
	efi_status_t status;

	efi_call_phys_prelog();
	status = efi_call_phys(efi_phys.get_time, tm, tc);
	efi_call_phys_epilog();
	return status;
}

inline int efi_set_rtc_mmss(unsigned long nowtime)
{
	int real_seconds, real_minutes;
	efi_status_t 	status;
	efi_time_t 	eft;
	efi_time_cap_t 	cap;

	spin_lock(&efi_rt_lock);
	status = efi.get_time(&eft, &cap);
	spin_unlock(&efi_rt_lock);
	if (status != EFI_SUCCESS)
		panic("Ooops, efitime: can't read time!\n");
	real_seconds = nowtime % 60;
	real_minutes = nowtime / 60;

	if (((abs(real_minutes - eft.minute) + 15)/30) & 1)
		real_minutes += 30;
	real_minutes %= 60;

	eft.minute = real_minutes;
	eft.second = real_seconds;

	if (status != EFI_SUCCESS) {
		printk("Ooops: efitime: can't read time!\n");
		return -1;
	}
	return 0;
}
/*
 * This should only be used during kernel init and before runtime
 * services have been remapped, therefore, we'll need to call in physical
 * mode.  Note, this call isn't used later, so mark it __init.
 */
inline unsigned long __init efi_get_time(void)
{
	efi_status_t status;
	efi_time_t eft;
	efi_time_cap_t cap;

	status = phys_efi_get_time(&eft, &cap);
	if (status != EFI_SUCCESS)
		printk("Oops: efitime: can't read time status: 0x%lx\n",status);

	return mktime(eft.year, eft.month, eft.day, eft.hour,
			eft.minute, eft.second);
}

int is_available_memory(efi_memory_desc_t * md)
{
	if (!(md->attribute & EFI_MEMORY_WB))
		return 0;

	switch (md->type) {
		case EFI_LOADER_CODE:
		case EFI_LOADER_DATA:
		case EFI_BOOT_SERVICES_CODE:
		case EFI_BOOT_SERVICES_DATA:
		case EFI_CONVENTIONAL_MEMORY:
			return 1;
	}
	return 0;
}

/*
 * 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);
}

#if EFI_DEBUG
static void __init print_efi_memmap(void)
{
	efi_memory_desc_t *md;
	void *p;
	int i;

	for (p = memmap.map, i = 0; p < memmap.map_end; p += memmap.desc_size, i++) {
		md = p;
		printk(KERN_INFO "mem%02u: type=%u, attr=0x%llx, "
			"range=[0x%016llx-0x%016llx) (%lluMB)\n",
			i, md->type, md->attribute, md->phys_addr,
			md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT),
			(md->num_pages >> (20 - EFI_PAGE_SHIFT)));
	}
}
#endif  /*  EFI_DEBUG  */

/*
 * Walks the EFI memory map and calls CALLBACK once for each EFI
 * memory descriptor that has memory that is available for kernel use.
 */
void efi_memmap_walk(efi_freemem_callback_t callback, void *arg)
{
	int prev_valid = 0;
	struct range {
		unsigned long start;
		unsigned long end;
	} prev, curr;
	efi_memory_desc_t *md;
	unsigned long start, end;
	void *p;

	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
		md = p;

		if ((md->num_pages == 0) || (!is_available_memory(md)))
			continue;

		curr.start = md->phys_addr;
		curr.end = curr.start + (md->num_pages << EFI_PAGE_SHIFT);

		if (!prev_valid) {
			prev = curr;
			prev_valid = 1;
		} else {
			if (curr.start < prev.start)
				printk(KERN_INFO PFX "Unordered memory map\n");
			if (prev.end == curr.start)
				prev.end = curr.end;
			else {
				start =
				    (unsigned long) (PAGE_ALIGN(prev.start));
				end = (unsigned long) (prev.end & PAGE_MASK);
				if ((end > start)
				    && (*callback) (start, end, arg) < 0)
					return;
				prev = curr;
			}
		}
	}
	if (prev_valid) {
		start = (unsigned long) PAGE_ALIGN(prev.start);
		end = (unsigned long) (prev.end & PAGE_MASK);
		if (end > start)
			(*callback) (start, end, arg);
	}
}

void __init efi_init(void)
{
	efi_config_table_t *config_tables;
	efi_runtime_services_t *runtime;
	efi_char16_t *c16;
	char vendor[100] = "unknown";
	unsigned long num_config_tables;
	int i = 0;