From 0f96a99dab366333439e110d6ad253bc7c557c09 Mon Sep 17 00:00:00 2001 From: Taku Izumi Date: Wed, 30 Sep 2015 23:01:56 +0900 Subject: [PATCH] efi: Add "efi_fake_mem" boot option This patch introduces new boot option named "efi_fake_mem". By specifying this parameter, you can add arbitrary attribute to specific memory range. This is useful for debugging of Address Range Mirroring feature. For example, if "efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000" is specified, the original (firmware provided) EFI memmap will be updated so that the specified memory regions have EFI_MEMORY_MORE_RELIABLE attribute (0x10000): efi: mem36: [Conventional Memory| | | | | | |WB|WT|WC|UC] range=[0x0000000100000000-0x00000020a0000000) (129536MB) efi: mem36: [Conventional Memory| |MR| | | | |WB|WT|WC|UC] range=[0x0000000100000000-0x0000000180000000) (2048MB) efi: mem37: [Conventional Memory| | | | | | |WB|WT|WC|UC] range=[0x0000000180000000-0x00000010a0000000) (61952MB) efi: mem38: [Conventional Memory| |MR| | | | |WB|WT|WC|UC] range=[0x00000010a0000000-0x0000001120000000) (2048MB) efi: mem39: [Conventional Memory| | | | | | |WB|WT|WC|UC] range=[0x0000001120000000-0x00000020a0000000) (63488MB) And you will find that the following message is output: efi: Memory: 4096M/131455M mirrored memory Signed-off-by: Taku Izumi Cc: Tony Luck Cc: Xishi Qiu Cc: Kamezawa Hiroyuki Cc: Ard Biesheuvel Signed-off-by: Matt Fleming --- Documentation/kernel-parameters.txt | 15 ++ arch/x86/kernel/setup.c | 4 +- drivers/firmware/efi/Kconfig | 22 +++ drivers/firmware/efi/Makefile | 1 + drivers/firmware/efi/fake_mem.c | 238 ++++++++++++++++++++++++++++ include/linux/efi.h | 6 + 6 files changed, 285 insertions(+), 1 deletion(-) create mode 100644 drivers/firmware/efi/fake_mem.c diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 1d6f0459cd7b..cd5312f24981 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1092,6 +1092,21 @@ bytes respectively. Such letter suffixes can also be entirely omitted. you are really sure that your UEFI does sane gc and fulfills the spec otherwise your board may brick. + efi_fake_mem= nn[KMG]@ss[KMG]:aa[,nn[KMG]@ss[KMG]:aa,..] [EFI; X86] + Add arbitrary attribute to specific memory range by + updating original EFI memory map. + Region of memory which aa attribute is added to is + from ss to ss+nn. + If efi_fake_mem=2G@4G:0x10000,2G@0x10a0000000:0x10000 + is specified, EFI_MEMORY_MORE_RELIABLE(0x10000) + attribute is added to range 0x100000000-0x180000000 and + 0x10a0000000-0x1120000000. + + Using this parameter you can do debugging of EFI memmap + related feature. For example, you can do debugging of + Address Range Mirroring feature even if your box + doesn't support it. + eisa_irq_edge= [PARISC,HW] See header of drivers/parisc/eisa.c. diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 80f874bf999e..e3ed628f7db4 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1104,8 +1104,10 @@ void __init setup_arch(char **cmdline_p) memblock_set_current_limit(ISA_END_ADDRESS); memblock_x86_fill(); - if (efi_enabled(EFI_BOOT)) + if (efi_enabled(EFI_BOOT)) { + efi_fake_memmap(); efi_find_mirror(); + } /* * The EFI specification says that boot service code won't be called diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 54071c148340..1de6f0ed5077 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -52,6 +52,28 @@ config EFI_RUNTIME_MAP See also Documentation/ABI/testing/sysfs-firmware-efi-runtime-map. +config EFI_FAKE_MEMMAP + bool "Enable EFI fake memory map" + depends on EFI && X86 + default n + help + Saying Y here will enable "efi_fake_mem" boot option. + By specifying this parameter, you can add arbitrary attribute + to specific memory range by updating original (firmware provided) + EFI memmap. + This is useful for debugging of EFI memmap related feature. + e.g. Address Range Mirroring feature. + +config EFI_MAX_FAKE_MEM + int "maximum allowable number of ranges in efi_fake_mem boot option" + depends on EFI_FAKE_MEMMAP + range 1 128 + default 8 + help + Maximum allowable number of ranges in efi_fake_mem boot option. + Ranges can be set up to this value using comma-separated list. + The default value is 8. + config EFI_PARAMS_FROM_FDT bool help diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index 6fd3da938717..c24f00569acb 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -9,3 +9,4 @@ obj-$(CONFIG_UEFI_CPER) += cper.o obj-$(CONFIG_EFI_RUNTIME_MAP) += runtime-map.o obj-$(CONFIG_EFI_RUNTIME_WRAPPERS) += runtime-wrappers.o obj-$(CONFIG_EFI_STUB) += libstub/ +obj-$(CONFIG_EFI_FAKE_MEMMAP) += fake_mem.o diff --git a/drivers/firmware/efi/fake_mem.c b/drivers/firmware/efi/fake_mem.c new file mode 100644 index 000000000000..32bcb14df2c8 --- /dev/null +++ b/drivers/firmware/efi/fake_mem.c @@ -0,0 +1,238 @@ +/* + * fake_mem.c + * + * Copyright (C) 2015 FUJITSU LIMITED + * Author: Taku Izumi + * + * 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 . + * + * The full GNU General Public License is included in this distribution in + * the file called "COPYING". + */ + +#include +#include +#include +#include +#include +#include +#include + +#define EFI_MAX_FAKEMEM CONFIG_EFI_MAX_FAKE_MEM + +struct fake_mem { + struct range range; + u64 attribute; +}; +static struct fake_mem fake_mems[EFI_MAX_FAKEMEM]; +static int nr_fake_mem; + +static int __init cmp_fake_mem(const void *x1, const void *x2) +{ + const struct fake_mem *m1 = x1; + const struct fake_mem *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) +{ + u64 start, end, m_start, m_end, m_attr; + int new_nr_map = memmap.nr_map; + efi_memory_desc_t *md; + u64 new_memmap_phy; + void *new_memmap; + void *old, *new; + int i; + + if (!nr_fake_mem || !efi_enabled(EFI_MEMMAP)) + return; + + /* count up the number of EFI memory descriptor */ + for (old = memmap.map; old < memmap.map_end; old += memmap.desc_size) { + md = old; + start = md->phys_addr; + end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1; + + for (i = 0; i < nr_fake_mem; i++) { + /* modifying range */ + m_start = fake_mems[i].range.start; + m_end = fake_mems[i].range.end; + + if (m_start <= start) { + /* split into 2 parts */ + if (start < m_end && m_end < end) + new_nr_map++; + } + if (start < m_start && m_start < end) { + /* split into 3 parts */ + if (m_end < end) + new_nr_map += 2; + /* split into 2 parts */ + if (end <= m_end) + new_nr_map++; + } + } + } + + /* allocate memory for new EFI memmap */ + new_memmap_phy = memblock_alloc(memmap.desc_size * new_nr_map, + PAGE_SIZE); + if (!new_memmap_phy) + return; + + /* create new EFI memmap */ + new_memmap = early_memremap(new_memmap_phy, + memmap.desc_size * new_nr_map); + if (!new_memmap) { + memblock_free(new_memmap_phy, memmap.desc_size * new_nr_map); + return; + } + + for (old = memmap.map, new = new_memmap; + old < memmap.map_end; + old += memmap.desc_size, new += memmap.desc_size) { + + /* copy original EFI memory descriptor */ + memcpy(new, old, memmap.desc_size); + md = new; + start = md->phys_addr; + end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1; + + for (i = 0; i < nr_fake_mem; i++) { + /* modifying range */ + m_start = fake_mems[i].range.start; + m_end = fake_mems[i].range.end; + m_attr = fake_mems[i].attribute; + + if (m_start <= start && end <= m_end) + md->attribute |= m_attr; + + if (m_start <= start && + (start < m_end && m_end < end)) { + /* first part */ + md->attribute |= m_attr; + md->num_pages = (m_end - md->phys_addr + 1) >> + EFI_PAGE_SHIFT; + /* latter part */ + new += memmap.desc_size; + memcpy(new, old, memmap.desc_size); + md = new; + md->phys_addr = m_end + 1; + md->num_pages = (end - md->phys_addr + 1) >> + EFI_PAGE_SHIFT; + } + + if ((start < m_start && m_start < end) && m_end < end) { + /* first part */ + md->num_pages = (m_start - md->phys_addr) >> + EFI_PAGE_SHIFT; + /* middle part */ + new += memmap.desc_size; + memcpy(new, old, memmap.desc_size); + md = new; + md->attribute |= m_attr; + md->phys_addr = m_start; + md->num_pages = (m_end - m_start + 1) >> + EFI_PAGE_SHIFT; + /* last part */ + new += memmap.desc_size; + memcpy(new, old, memmap.desc_size); + md = new; + md->phys_addr = m_end + 1; + md->num_pages = (end - m_end) >> + EFI_PAGE_SHIFT; + } + + if ((start < m_start && m_start < end) && + (end <= m_end)) { + /* first part */ + md->num_pages = (m_start - md->phys_addr) >> + EFI_PAGE_SHIFT; + /* latter part */ + new += memmap.desc_size; + memcpy(new, old, memmap.desc_size); + md = new; + md->phys_addr = m_start; + md->num_pages = (end - md->phys_addr + 1) >> + EFI_PAGE_SHIFT; + md->attribute |= m_attr; + } + } + } + + /* swap into new EFI memmap */ + efi_unmap_memmap(); + memmap.map = new_memmap; + memmap.phys_map = (void *)new_memmap_phy; + memmap.nr_map = new_nr_map; + memmap.map_end = memmap.map + memmap.nr_map * memmap.desc_size; + set_bit(EFI_MEMMAP, &efi.flags); + + /* 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 fake_mem), + 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); diff --git a/include/linux/efi.h b/include/linux/efi.h index fa5106c2f9f5..4d01c1033fce 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -922,6 +922,12 @@ extern struct kobject *efi_kobj; extern int efi_reboot_quirk_mode; extern bool efi_poweroff_required(void); +#ifdef CONFIG_EFI_FAKE_MEMMAP +extern void __init efi_fake_memmap(void); +#else +static inline void efi_fake_memmap(void) { } +#endif + /* Iterate through an efi_memory_map */ #define for_each_efi_memory_desc(m, md) \ for ((md) = (m)->map; \ -- 2.20.1