[linux-2.6-block.git] / drivers / firmware / efi / fake_mem.c

/*
 * fake_mem.c
 *
 * Copyright (C) 2015 FUJITSU LIMITED
 * Author: Taku Izumi <izumi.taku@jp.fujitsu.com>
 *
 * This code introduces new boot option named "efi_fake_mem"
 * By specifying this parameter, you can add arbitrary attribute to
 * specific memory range by updating original (firmware provided) EFI
 * memmap.
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms and conditions of the GNU General Public License,
 *  version 2, as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope it will be useful, but WITHOUT
 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 *  more details.
 *
 *  You should have received a copy of the GNU General Public License along with
 *  this program; if not, see <http://www.gnu.org/licenses/>.
 *
 *  The full GNU General Public License is included in this distribution in
 *  the file called "COPYING".
 */

#include <linux/kernel.h>
#include <linux/efi.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/types.h>
#include <linux/sort.h>
#include <asm/efi.h>

#define EFI_MAX_FAKEMEM CONFIG_EFI_MAX_FAKE_MEM

static struct efi_mem_range fake_mems[EFI_MAX_FAKEMEM];
static int nr_fake_mem;

static int __init cmp_fake_mem(const void *x1, const void *x2)
{
	const struct efi_mem_range *m1 = x1;
	const struct efi_mem_range *m2 = x2;

	if (m1->range.start < m2->range.start)
		return -1;
	if (m1->range.start > m2->range.start)
		return 1;
	return 0;
}

void __init efi_fake_memmap(void)
{
	int new_nr_map = efi.memmap.nr_map;
	efi_memory_desc_t *md;
	phys_addr_t new_memmap_phy;
	void *new_memmap;
	int i;

	if (!nr_fake_mem)
		return;

	/* count up the number of EFI memory descriptor */
	for (i = 0; i < nr_fake_mem; i++) {
		for_each_efi_memory_desc(md) {
			struct range *r = &fake_mems[i].range;

			new_nr_map += efi_memmap_split_count(md, r);
		}
	}

	/* allocate memory for new EFI memmap */
	new_memmap_phy = memblock_alloc(efi.memmap.desc_size * new_nr_map,
					PAGE_SIZE);
	if (!new_memmap_phy)
		return;

	/* create new EFI memmap */
	new_memmap = early_memremap(new_memmap_phy,
				    efi.memmap.desc_size * new_nr_map);
	if (!new_memmap) {
		memblock_free(new_memmap_phy, efi.memmap.desc_size * new_nr_map);
		return;
	}

	for (i = 0; i < nr_fake_mem; i++)
		efi_memmap_insert(&efi.memmap, new_memmap, &fake_mems[i]);

	/* swap into new EFI memmap */
	early_memunmap(new_memmap, efi.memmap.desc_size * new_nr_map);

	efi_memmap_install(new_memmap_phy, new_nr_map);

	/* print new EFI memmap */
	efi_print_memmap();
}

static int __init setup_fake_mem(char *p)
{
	u64 start = 0, mem_size = 0, attribute = 0;
	int i;

	if (!p)
		return -EINVAL;

	while (*p != '\0') {
		mem_size = memparse(p, &p);
		if (*p == '@')
			start = memparse(p+1, &p);
		else
			break;

		if (*p == ':')
			attribute = simple_strtoull(p+1, &p, 0);
		else
			break;

		if (nr_fake_mem >= EFI_MAX_FAKEMEM)
			break;

		fake_mems[nr_fake_mem].range.start = start;
		fake_mems[nr_fake_mem].range.end = start + mem_size - 1;
		fake_mems[nr_fake_mem].attribute = attribute;
		nr_fake_mem++;

		if (*p == ',')
			p++;
	}

	sort(fake_mems, nr_fake_mem, sizeof(struct efi_mem_range),
	     cmp_fake_mem, NULL);

	for (i = 0; i < nr_fake_mem; i++)
		pr_info("efi_fake_mem: add attr=0x%016llx to [mem 0x%016llx-0x%016llx]",
			fake_mems[i].attribute, fake_mems[i].range.start,
			fake_mems[i].range.end);

	return *p == '\0' ? 0 : -EINVAL;
}

early_param("efi_fake_mem", setup_fake_mem);
Commit	Line	Data
0f96a99d TI	1	/*
	2	* fake_mem.c
	3	*
	4	* Copyright (C) 2015 FUJITSU LIMITED
	5	* Author: Taku Izumi <izumi.taku@jp.fujitsu.com>
	6	*
	7	* This code introduces new boot option named "efi_fake_mem"
	8	* By specifying this parameter, you can add arbitrary attribute to
	9	* specific memory range by updating original (firmware provided) EFI
	10	* memmap.
	11	*
	12	* This program is free software; you can redistribute it and/or modify it
	13	* under the terms and conditions of the GNU General Public License,
	14	* version 2, as published by the Free Software Foundation.
	15	*
	16	* This program is distributed in the hope it will be useful, but WITHOUT
	17	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	18	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	19	* more details.
	20	*
	21	* You should have received a copy of the GNU General Public License along with
	22	* this program; if not, see <http://www.gnu.org/licenses/>.
	23	*
	24	* The full GNU General Public License is included in this distribution in
	25	* the file called "COPYING".
	26	*/
	27
	28	#include <linux/kernel.h>
	29	#include <linux/efi.h>
	30	#include <linux/init.h>
	31	#include <linux/memblock.h>
	32	#include <linux/types.h>
	33	#include <linux/sort.h>
	34	#include <asm/efi.h>
	35
	36	#define EFI_MAX_FAKEMEM CONFIG_EFI_MAX_FAKE_MEM
	37
60863c0d	38	static struct efi_mem_range fake_mems[EFI_MAX_FAKEMEM];
0f96a99d TI	39	static int nr_fake_mem;
	40
	41	static int __init cmp_fake_mem(const void x1, const void x2)
	42	{
60863c0d MF	43	const struct efi_mem_range *m1 = x1;
60863c0d MF	44	const struct efi_mem_range *m2 = x2;
0f96a99d TI	45
	46	if (m1->range.start < m2->range.start)
	47	return -1;
	48	if (m1->range.start > m2->range.start)
	49	return 1;
	50	return 0;
	51	}
	52
	53	void __init efi_fake_memmap(void)
	54	{
884f4f66	55	int new_nr_map = efi.memmap.nr_map;
0f96a99d	56	efi_memory_desc_t *md;
78b9bc94	57	phys_addr_t new_memmap_phy;
0f96a99d	58	void *new_memmap;
0f96a99d TI	59	int i;
0f96a99d TI	60
4971531a	61	if (!nr_fake_mem)
0f96a99d TI	62	return;
	63
	64	/* count up the number of EFI memory descriptor */
c8c1a4c5 MF	65	for (i = 0; i < nr_fake_mem; i++) {
	66	for_each_efi_memory_desc(md) {
	67	struct range *r = &fake_mems[i].range;
	68
60863c0d	69	new_nr_map += efi_memmap_split_count(md, r);
0f96a99d TI	70	}
	71	}
	72
	73	/* allocate memory for new EFI memmap */
884f4f66	74	new_memmap_phy = memblock_alloc(efi.memmap.desc_size * new_nr_map,
0f96a99d TI	75	PAGE_SIZE);
	76	if (!new_memmap_phy)
	77	return;
	78
	79	/* create new EFI memmap */
	80	new_memmap = early_memremap(new_memmap_phy,
884f4f66	81	efi.memmap.desc_size * new_nr_map);
0f96a99d	82	if (!new_memmap) {
884f4f66	83	memblock_free(new_memmap_phy, efi.memmap.desc_size * new_nr_map);
0f96a99d TI	84	return;
	85	}
	86
c8c1a4c5	87	for (i = 0; i < nr_fake_mem; i++)
60863c0d	88	efi_memmap_insert(&efi.memmap, new_memmap, &fake_mems[i]);
0f96a99d TI	89
0f96a99d TI	90	/* swap into new EFI memmap */
9479c7ce	91	early_memunmap(new_memmap, efi.memmap.desc_size * new_nr_map);
9479c7ce	92
c45f4da3	93	efi_memmap_install(new_memmap_phy, new_nr_map);
0f96a99d TI	94
	95	/* print new EFI memmap */
	96	efi_print_memmap();
	97	}
	98
	99	static int __init setup_fake_mem(char *p)
	100	{
	101	u64 start = 0, mem_size = 0, attribute = 0;
	102	int i;
	103
	104	if (!p)
	105	return -EINVAL;
	106
	107	while (*p != '\0') {
	108	mem_size = memparse(p, &p);
	109	if (*p == '@')
	110	start = memparse(p+1, &p);
	111	else
	112	break;
	113
	114	if (*p == ':')
	115	attribute = simple_strtoull(p+1, &p, 0);
	116	else
	117	break;
	118
	119	if (nr_fake_mem >= EFI_MAX_FAKEMEM)
	120	break;
	121
	122	fake_mems[nr_fake_mem].range.start = start;
	123	fake_mems[nr_fake_mem].range.end = start + mem_size - 1;
	124	fake_mems[nr_fake_mem].attribute = attribute;
	125	nr_fake_mem++;
	126
	127	if (*p == ',')
	128	p++;
	129	}
	130
60863c0d	131	sort(fake_mems, nr_fake_mem, sizeof(struct efi_mem_range),
0f96a99d TI	132	cmp_fake_mem, NULL);
	133
	134	for (i = 0; i < nr_fake_mem; i++)
	135	pr_info("efi_fake_mem: add attr=0x%016llx to [mem 0x%016llx-0x%016llx]",
	136	fake_mems[i].attribute, fake_mems[i].range.start,
	137	fake_mems[i].range.end);
	138
	139	return *p == '\0' ? 0 : -EINVAL;
	140	}
	141
	142	early_param("efi_fake_mem", setup_fake_mem);