[mirror_ubuntu-artful-kernel.git] / arch / x86 / kernel / efi_64.c

/*
 * x86_64 specific EFI support functions
 * Based on Extensible Firmware Interface Specification version 1.0
 *
 * Copyright (C) 2005-2008 Intel Co.
 *	Fenghua Yu <fenghua.yu@intel.com>
 *	Bibo Mao <bibo.mao@intel.com>
 *	Chandramouli Narayanan <mouli@linux.intel.com>
 *	Huang Ying <ying.huang@intel.com>
 *
 * Code to convert EFI to E820 map has been implemented in elilo bootloader
 * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
 * is setup appropriately for EFI runtime code.
 * - mouli 06/14/2007.
 *
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/bootmem.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/efi.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/reboot.h>

#include <asm/setup.h>
#include <asm/page.h>
#include <asm/e820.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/proto.h>
#include <asm/efi.h>

static pgd_t save_pgd __initdata;
static unsigned long efi_flags __initdata;

static void __init early_mapping_set_exec(unsigned long start,
					  unsigned long end,
					  int executable)
{
	pte_t *kpte;
	int level;

	while (start < end) {
		kpte = lookup_address((unsigned long)__va(start), &level);
		BUG_ON(!kpte);
		if (executable)
			set_pte(kpte, pte_mkexec(*kpte));
		else
			set_pte(kpte, __pte((pte_val(*kpte) | _PAGE_NX) & \
					    __supported_pte_mask));
		if (pte_huge(*kpte))
			start = (start + PMD_SIZE) & PMD_MASK;
		else
			start = (start + PAGE_SIZE) & PAGE_MASK;
	}
}

static void __init early_runtime_code_mapping_set_exec(int executable)
{
	efi_memory_desc_t *md;
	void *p;

	/* Make EFI runtime service code area executable */
	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
		md = p;
		if (md->type == EFI_RUNTIME_SERVICES_CODE) {
			unsigned long end;
			end = md->phys_addr + (md->num_pages << PAGE_SHIFT);
			early_mapping_set_exec(md->phys_addr, end, executable);
		}
	}
}

void __init efi_call_phys_prelog(void)
{
	unsigned long vaddress;

	local_irq_save(efi_flags);
	early_runtime_code_mapping_set_exec(1);
	vaddress = (unsigned long)__va(0x0UL);
	pgd_val(save_pgd) = pgd_val(*pgd_offset_k(0x0UL));
	set_pgd(pgd_offset_k(0x0UL), *pgd_offset_k(vaddress));
	__flush_tlb_all();
}

void __init efi_call_phys_epilog(void)
{
	/*
	 * After the lock is released, the original page table is restored.
	 */
	set_pgd(pgd_offset_k(0x0UL), save_pgd);
	early_runtime_code_mapping_set_exec(0);
	__flush_tlb_all();
	local_irq_restore(efi_flags);
}

/*
 * We need to map the EFI memory map again after init_memory_mapping().
 */
void __init efi_map_memmap(void)
{
	memmap.map = __va(memmap.phys_map);
	memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
}

void __init efi_reserve_bootmem(void)
{
	reserve_bootmem_generic((unsigned long)memmap.phys_map,
				memmap.nr_map * memmap.desc_size);
}

void __init runtime_code_page_mkexec(void)
{
	efi_memory_desc_t *md;
	void *p;

	/* Make EFI runtime service code area executable */
	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
		md = p;
		if (md->type == EFI_RUNTIME_SERVICES_CODE)
			change_page_attr_addr(md->virt_addr,
					      md->num_pages,
					      PAGE_KERNEL_EXEC);
	}
	__flush_tlb_all();
}

void __iomem * __init efi_ioremap(unsigned long offset,
				  unsigned long size)
{
	static unsigned pages_mapped;
	unsigned long last_addr;
	unsigned i, pages;

	last_addr = offset + size - 1;
	offset &= PAGE_MASK;
	pages = (PAGE_ALIGN(last_addr) - offset) >> PAGE_SHIFT;
	if (pages_mapped + pages > MAX_EFI_IO_PAGES)
		return NULL;

	for (i = 0; i < pages; i++) {
		set_fixmap_nocache(FIX_EFI_IO_MAP_FIRST_PAGE - pages_mapped,
				   offset);
		offset += PAGE_SIZE;
		pages_mapped++;
	}

	return (void __iomem *)__fix_to_virt(FIX_EFI_IO_MAP_FIRST_PAGE - \
					     (pages_mapped - pages));
}
Commit	Line	Data
5b83683f HY	1	/*
	2	* x86_64 specific EFI support functions
	3	* Based on Extensible Firmware Interface Specification version 1.0
	4	*
	5	* Copyright (C) 2005-2008 Intel Co.
	6	* Fenghua Yu <fenghua.yu@intel.com>
	7	* Bibo Mao <bibo.mao@intel.com>
	8	* Chandramouli Narayanan <mouli@linux.intel.com>
	9	* Huang Ying <ying.huang@intel.com>
	10	*
	11	* Code to convert EFI to E820 map has been implemented in elilo bootloader
	12	* based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
	13	* is setup appropriately for EFI runtime code.
	14	* - mouli 06/14/2007.
	15	*
	16	*/
	17
	18	#include <linux/kernel.h>
	19	#include <linux/init.h>
	20	#include <linux/mm.h>
	21	#include <linux/types.h>
	22	#include <linux/spinlock.h>
	23	#include <linux/bootmem.h>
	24	#include <linux/ioport.h>
	25	#include <linux/module.h>
	26	#include <linux/efi.h>
	27	#include <linux/uaccess.h>
	28	#include <linux/io.h>
	29	#include <linux/reboot.h>
	30
	31	#include <asm/setup.h>
	32	#include <asm/page.h>
	33	#include <asm/e820.h>
	34	#include <asm/pgtable.h>
	35	#include <asm/tlbflush.h>
	36	#include <asm/cacheflush.h>
	37	#include <asm/proto.h>
	38	#include <asm/efi.h>
	39
	40	static pgd_t save_pgd __initdata;
	41	static unsigned long efi_flags __initdata;
	42
5b83683f HY	43	static void __init early_mapping_set_exec(unsigned long start,
	44	unsigned long end,
	45	int executable)
	46	{
	47	pte_t *kpte;
	48	int level;
	49
	50	while (start < end) {
	51	kpte = lookup_address((unsigned long)__va(start), &level);
	52	BUG_ON(!kpte);
	53	if (executable)
	54	set_pte(kpte, pte_mkexec(*kpte));
	55	else
	56	set_pte(kpte, __pte((pte_val(*kpte) \| _PAGE_NX) & \
	57	__supported_pte_mask));
	58	if (pte_huge(*kpte))
	59	start = (start + PMD_SIZE) & PMD_MASK;
	60	else
	61	start = (start + PAGE_SIZE) & PAGE_MASK;
	62	}
	63	}
	64
	65	static void __init early_runtime_code_mapping_set_exec(int executable)
	66	{
	67	efi_memory_desc_t *md;
	68	void *p;
	69
	70	/* Make EFI runtime service code area executable */
	71	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
	72	md = p;
	73	if (md->type == EFI_RUNTIME_SERVICES_CODE) {
	74	unsigned long end;
	75	end = md->phys_addr + (md->num_pages << PAGE_SHIFT);
	76	early_mapping_set_exec(md->phys_addr, end, executable);
	77	}
	78	}
	79	}
	80
	81	void __init efi_call_phys_prelog(void)
	82	{
	83	unsigned long vaddress;
	84
	85	local_irq_save(efi_flags);
	86	early_runtime_code_mapping_set_exec(1);
	87	vaddress = (unsigned long)__va(0x0UL);
	88	pgd_val(save_pgd) = pgd_val(*pgd_offset_k(0x0UL));
	89	set_pgd(pgd_offset_k(0x0UL), *pgd_offset_k(vaddress));
	90	__flush_tlb_all();
	91	}
	92
	93	void __init efi_call_phys_epilog(void)
	94	{
	95	/*
	96	* After the lock is released, the original page table is restored.
	97	*/
	98	set_pgd(pgd_offset_k(0x0UL), save_pgd);
	99	early_runtime_code_mapping_set_exec(0);
	100	__flush_tlb_all();
	101	local_irq_restore(efi_flags);
	102	}
	103
	104	/*
	105	* We need to map the EFI memory map again after init_memory_mapping().
	106	*/
107	void __init efi_map_memmap(void)
108	{
109	memmap.map = __va(memmap.phys_map);
110	memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
111	}
112
113	void __init efi_reserve_bootmem(void)
114	{
115	reserve_bootmem_generic((unsigned long)memmap.phys_map,
116	memmap.nr_map * memmap.desc_size);
117	}
118
119	void __init runtime_code_page_mkexec(void)
120	{
121	efi_memory_desc_t *md;
122	void *p;
123
124	/* Make EFI runtime service code area executable */
125	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
126	md = p;
127	if (md->type == EFI_RUNTIME_SERVICES_CODE)
128	change_page_attr_addr(md->virt_addr,
129	md->num_pages,
130	PAGE_KERNEL_EXEC);
131	}
132	__flush_tlb_all();
133	}
134
135	void __iomem * __init efi_ioremap(unsigned long offset,
136	unsigned long size)
137	{
138	static unsigned pages_mapped;
139	unsigned long last_addr;
140	unsigned i, pages;
141
142	last_addr = offset + size - 1;
143	offset &= PAGE_MASK;
144	pages = (PAGE_ALIGN(last_addr) - offset) >> PAGE_SHIFT;
145	if (pages_mapped + pages > MAX_EFI_IO_PAGES)
146	return NULL;
147
148	for (i = 0; i < pages; i++) {
149	set_fixmap_nocache(FIX_EFI_IO_MAP_FIRST_PAGE - pages_mapped,
150	offset);
151	offset += PAGE_SIZE;
152	pages_mapped++;
153	}
154
155	return (void __iomem *)__fix_to_virt(FIX_EFI_IO_MAP_FIRST_PAGE - \
156	(pages_mapped - pages));
157	}