140 lines
3.4 KiB
C
140 lines
3.4 KiB
C
/*
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* fake_mem.c
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*
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* Copyright (C) 2015 FUJITSU LIMITED
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* Author: Taku Izumi <izumi.taku@jp.fujitsu.com>
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*
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* This code introduces new boot option named "efi_fake_mem"
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* By specifying this parameter, you can add arbitrary attribute to
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* specific memory range by updating original (firmware provided) EFI
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* memmap.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, see <http://www.gnu.org/licenses/>.
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*
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* The full GNU General Public License is included in this distribution in
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* the file called "COPYING".
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*/
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#include <linux/kernel.h>
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#include <linux/efi.h>
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#include <linux/init.h>
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#include <linux/memblock.h>
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#include <linux/types.h>
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#include <linux/sort.h>
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#include <asm/efi.h>
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#define EFI_MAX_FAKEMEM CONFIG_EFI_MAX_FAKE_MEM
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static struct efi_mem_range fake_mems[EFI_MAX_FAKEMEM];
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static int nr_fake_mem;
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static int __init cmp_fake_mem(const void *x1, const void *x2)
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{
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const struct efi_mem_range *m1 = x1;
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const struct efi_mem_range *m2 = x2;
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if (m1->range.start < m2->range.start)
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return -1;
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if (m1->range.start > m2->range.start)
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return 1;
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return 0;
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}
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void __init efi_fake_memmap(void)
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{
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struct efi_memory_map_data data = { 0 };
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int new_nr_map = efi.memmap.nr_map;
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efi_memory_desc_t *md;
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void *new_memmap;
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int i;
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if (!efi_enabled(EFI_MEMMAP) || !nr_fake_mem)
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return;
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/* count up the number of EFI memory descriptor */
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for (i = 0; i < nr_fake_mem; i++) {
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for_each_efi_memory_desc(md) {
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struct range *r = &fake_mems[i].range;
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new_nr_map += efi_memmap_split_count(md, r);
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}
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}
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/* allocate memory for new EFI memmap */
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if (efi_memmap_alloc(new_nr_map, &data) != 0)
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return;
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/* create new EFI memmap */
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new_memmap = early_memremap(data.phys_map, data.size);
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if (!new_memmap) {
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memblock_free(data.phys_map, data.size);
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return;
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}
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for (i = 0; i < nr_fake_mem; i++)
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efi_memmap_insert(&efi.memmap, new_memmap, &fake_mems[i]);
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/* swap into new EFI memmap */
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early_memunmap(new_memmap, data.size);
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efi_memmap_install(&data);
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/* print new EFI memmap */
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efi_print_memmap();
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}
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static int __init setup_fake_mem(char *p)
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{
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u64 start = 0, mem_size = 0, attribute = 0;
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int i;
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if (!p)
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return -EINVAL;
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while (*p != '\0') {
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mem_size = memparse(p, &p);
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if (*p == '@')
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start = memparse(p+1, &p);
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else
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break;
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if (*p == ':')
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attribute = simple_strtoull(p+1, &p, 0);
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else
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break;
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if (nr_fake_mem >= EFI_MAX_FAKEMEM)
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break;
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fake_mems[nr_fake_mem].range.start = start;
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fake_mems[nr_fake_mem].range.end = start + mem_size - 1;
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fake_mems[nr_fake_mem].attribute = attribute;
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nr_fake_mem++;
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if (*p == ',')
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p++;
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}
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sort(fake_mems, nr_fake_mem, sizeof(struct efi_mem_range),
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cmp_fake_mem, NULL);
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for (i = 0; i < nr_fake_mem; i++)
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pr_info("efi_fake_mem: add attr=0x%016llx to [mem 0x%016llx-0x%016llx]",
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fake_mems[i].attribute, fake_mems[i].range.start,
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fake_mems[i].range.end);
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return *p == '\0' ? 0 : -EINVAL;
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}
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early_param("efi_fake_mem", setup_fake_mem);
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