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Diffstat (limited to 'arch/x86/platform/efi/efi.c')
-rw-r--r--arch/x86/platform/efi/efi.c1342
1 files changed, 1342 insertions, 0 deletions
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
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index 00000000000..87fc96bcc13
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+++ b/arch/x86/platform/efi/efi.c
@@ -0,0 +1,1342 @@
+/*
+ * Common EFI (Extensible Firmware Interface) support functions
+ * Based on Extensible Firmware Interface Specification version 1.0
+ *
+ * Copyright (C) 1999 VA Linux Systems
+ * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
+ * Copyright (C) 1999-2002 Hewlett-Packard Co.
+ * David Mosberger-Tang <davidm@hpl.hp.com>
+ * Stephane Eranian <eranian@hpl.hp.com>
+ * 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>
+ * Copyright (C) 2013 SuSE Labs
+ * Borislav Petkov <bp@suse.de> - runtime services VA mapping
+ *
+ * Copied from efi_32.c to eliminate the duplicated code between EFI
+ * 32/64 support code. --ying 2007-10-26
+ *
+ * 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: <goutham.rao@intel.com>
+ * Skip non-WB memory and ignore empty memory ranges.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/efi.h>
+#include <linux/efi-bgrt.h>
+#include <linux/export.h>
+#include <linux/bootmem.h>
+#include <linux/slab.h>
+#include <linux/memblock.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/time.h>
+#include <linux/io.h>
+#include <linux/reboot.h>
+#include <linux/bcd.h>
+
+#include <asm/setup.h>
+#include <asm/efi.h>
+#include <asm/time.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/x86_init.h>
+#include <asm/rtc.h>
+#include <asm/uv/uv.h>
+
+#define EFI_DEBUG
+
+#define EFI_MIN_RESERVE 5120
+
+#define EFI_DUMMY_GUID \
+ EFI_GUID(0x4424ac57, 0xbe4b, 0x47dd, 0x9e, 0x97, 0xed, 0x50, 0xf0, 0x9f, 0x92, 0xa9)
+
+static efi_char16_t efi_dummy_name[6] = { 'D', 'U', 'M', 'M', 'Y', 0 };
+
+struct efi_memory_map memmap;
+
+static struct efi efi_phys __initdata;
+static efi_system_table_t efi_systab __initdata;
+
+static efi_config_table_type_t arch_tables[] __initdata = {
+#ifdef CONFIG_X86_UV
+ {UV_SYSTEM_TABLE_GUID, "UVsystab", &efi.uv_systab},
+#endif
+ {NULL_GUID, NULL, NULL},
+};
+
+u64 efi_setup; /* efi setup_data physical address */
+
+static bool disable_runtime __initdata = false;
+static int __init setup_noefi(char *arg)
+{
+ disable_runtime = true;
+ return 0;
+}
+early_param("noefi", setup_noefi);
+
+int add_efi_memmap;
+EXPORT_SYMBOL(add_efi_memmap);
+
+static int __init setup_add_efi_memmap(char *arg)
+{
+ add_efi_memmap = 1;
+ return 0;
+}
+early_param("add_efi_memmap", setup_add_efi_memmap);
+
+static bool efi_no_storage_paranoia;
+
+static int __init setup_storage_paranoia(char *arg)
+{
+ efi_no_storage_paranoia = true;
+ return 0;
+}
+early_param("efi_no_storage_paranoia", setup_storage_paranoia);
+
+static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
+{
+ unsigned long flags;
+ efi_status_t status;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ status = efi_call_virt(get_time, tm, tc);
+ spin_unlock_irqrestore(&rtc_lock, flags);
+ return status;
+}
+
+static efi_status_t virt_efi_set_time(efi_time_t *tm)
+{
+ unsigned long flags;
+ efi_status_t status;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ status = efi_call_virt(set_time, tm);
+ spin_unlock_irqrestore(&rtc_lock, flags);
+ return status;
+}
+
+static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
+ efi_bool_t *pending,
+ efi_time_t *tm)
+{
+ unsigned long flags;
+ efi_status_t status;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ status = efi_call_virt(get_wakeup_time, enabled, pending, tm);
+ spin_unlock_irqrestore(&rtc_lock, flags);
+ return status;
+}
+
+static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
+{
+ unsigned long flags;
+ efi_status_t status;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ status = efi_call_virt(set_wakeup_time, enabled, tm);
+ spin_unlock_irqrestore(&rtc_lock, flags);
+ return status;
+}
+
+static efi_status_t virt_efi_get_variable(efi_char16_t *name,
+ efi_guid_t *vendor,
+ u32 *attr,
+ unsigned long *data_size,
+ void *data)
+{
+ return efi_call_virt(get_variable,
+ name, vendor, attr,
+ data_size, data);
+}
+
+static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
+ efi_char16_t *name,
+ efi_guid_t *vendor)
+{
+ return efi_call_virt(get_next_variable,
+ name_size, name, vendor);
+}
+
+static efi_status_t virt_efi_set_variable(efi_char16_t *name,
+ efi_guid_t *vendor,
+ u32 attr,
+ unsigned long data_size,
+ void *data)
+{
+ return efi_call_virt(set_variable,
+ name, vendor, attr,
+ data_size, data);
+}
+
+static efi_status_t virt_efi_query_variable_info(u32 attr,
+ u64 *storage_space,
+ u64 *remaining_space,
+ u64 *max_variable_size)
+{
+ if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
+ return EFI_UNSUPPORTED;
+
+ return efi_call_virt(query_variable_info, attr, storage_space,
+ remaining_space, max_variable_size);
+}
+
+static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
+{
+ return efi_call_virt(get_next_high_mono_count, count);
+}
+
+static void virt_efi_reset_system(int reset_type,
+ efi_status_t status,
+ unsigned long data_size,
+ efi_char16_t *data)
+{
+ __efi_call_virt(reset_system, reset_type, status,
+ data_size, data);
+}
+
+static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
+ unsigned long count,
+ unsigned long sg_list)
+{
+ if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
+ return EFI_UNSUPPORTED;
+
+ return efi_call_virt(update_capsule, capsules, count, sg_list);
+}
+
+static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
+ unsigned long count,
+ u64 *max_size,
+ int *reset_type)
+{
+ if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
+ return EFI_UNSUPPORTED;
+
+ return efi_call_virt(query_capsule_caps, capsules, count, max_size,
+ reset_type);
+}
+
+static efi_status_t __init 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;
+}
+
+int efi_set_rtc_mmss(const struct timespec *now)
+{
+ unsigned long nowtime = now->tv_sec;
+ efi_status_t status;
+ efi_time_t eft;
+ efi_time_cap_t cap;
+ struct rtc_time tm;
+
+ status = efi.get_time(&eft, &cap);
+ if (status != EFI_SUCCESS) {
+ pr_err("Oops: efitime: can't read time!\n");
+ return -1;
+ }
+
+ rtc_time_to_tm(nowtime, &tm);
+ if (!rtc_valid_tm(&tm)) {
+ eft.year = tm.tm_year + 1900;
+ eft.month = tm.tm_mon + 1;
+ eft.day = tm.tm_mday;
+ eft.minute = tm.tm_min;
+ eft.second = tm.tm_sec;
+ eft.nanosecond = 0;
+ } else {
+ pr_err("%s: Invalid EFI RTC value: write of %lx to EFI RTC failed\n",
+ __func__, nowtime);
+ return -1;
+ }
+
+ status = efi.set_time(&eft);
+ if (status != EFI_SUCCESS) {
+ pr_err("Oops: efitime: can't write time!\n");
+ return -1;
+ }
+ return 0;
+}
+
+void efi_get_time(struct timespec *now)
+{
+ efi_status_t status;
+ efi_time_t eft;
+ efi_time_cap_t cap;
+
+ status = efi.get_time(&eft, &cap);
+ if (status != EFI_SUCCESS)
+ pr_err("Oops: efitime: can't read time!\n");
+
+ now->tv_sec = mktime(eft.year, eft.month, eft.day, eft.hour,
+ eft.minute, eft.second);
+ now->tv_nsec = 0;
+}
+
+/*
+ * Tell the kernel about the EFI memory map. This might include
+ * more than the max 128 entries that can fit in the e820 legacy
+ * (zeropage) memory map.
+ */
+
+static void __init do_add_efi_memmap(void)
+{
+ void *p;
+
+ for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+ efi_memory_desc_t *md = p;
+ unsigned long long start = md->phys_addr;
+ unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
+ int e820_type;
+
+ 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:
+ if (md->attribute & EFI_MEMORY_WB)
+ e820_type = E820_RAM;
+ else
+ e820_type = E820_RESERVED;
+ break;
+ case EFI_ACPI_RECLAIM_MEMORY:
+ e820_type = E820_ACPI;
+ break;
+ case EFI_ACPI_MEMORY_NVS:
+ e820_type = E820_NVS;
+ break;
+ case EFI_UNUSABLE_MEMORY:
+ e820_type = E820_UNUSABLE;
+ break;
+ default:
+ /*
+ * EFI_RESERVED_TYPE EFI_RUNTIME_SERVICES_CODE
+ * EFI_RUNTIME_SERVICES_DATA EFI_MEMORY_MAPPED_IO
+ * EFI_MEMORY_MAPPED_IO_PORT_SPACE EFI_PAL_CODE
+ */
+ e820_type = E820_RESERVED;
+ break;
+ }
+ e820_add_region(start, size, e820_type);
+ }
+ sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+}
+
+int __init efi_memblock_x86_reserve_range(void)
+{
+ struct efi_info *e = &boot_params.efi_info;
+ unsigned long pmap;
+
+#ifdef CONFIG_X86_32
+ /* Can't handle data above 4GB at this time */
+ if (e->efi_memmap_hi) {
+ pr_err("Memory map is above 4GB, disabling EFI.\n");
+ return -EINVAL;
+ }
+ pmap = e->efi_memmap;
+#else
+ pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32));
+#endif
+ memmap.phys_map = (void *)pmap;
+ memmap.nr_map = e->efi_memmap_size /
+ e->efi_memdesc_size;
+ memmap.desc_size = e->efi_memdesc_size;
+ memmap.desc_version = e->efi_memdesc_version;
+
+ memblock_reserve(pmap, memmap.nr_map * memmap.desc_size);
+
+ efi.memmap = &memmap;
+
+ return 0;
+}
+
+static void __init print_efi_memmap(void)
+{
+#ifdef EFI_DEBUG
+ 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;
+ pr_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 */
+}
+
+void __init efi_reserve_boot_services(void)
+{
+ void *p;
+
+ for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+ efi_memory_desc_t *md = p;
+ u64 start = md->phys_addr;
+ u64 size = md->num_pages << EFI_PAGE_SHIFT;
+
+ if (md->type != EFI_BOOT_SERVICES_CODE &&
+ md->type != EFI_BOOT_SERVICES_DATA)
+ continue;
+ /* Only reserve where possible:
+ * - Not within any already allocated areas
+ * - Not over any memory area (really needed, if above?)
+ * - Not within any part of the kernel
+ * - Not the bios reserved area
+ */
+ if ((start + size > __pa_symbol(_text)
+ && start <= __pa_symbol(_end)) ||
+ !e820_all_mapped(start, start+size, E820_RAM) ||
+ memblock_is_region_reserved(start, size)) {
+ /* Could not reserve, skip it */
+ md->num_pages = 0;
+ memblock_dbg("Could not reserve boot range [0x%010llx-0x%010llx]\n",
+ start, start+size-1);
+ } else
+ memblock_reserve(start, size);
+ }
+}
+
+void __init efi_unmap_memmap(void)
+{
+ clear_bit(EFI_MEMMAP, &efi.flags);
+ if (memmap.map) {
+ early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size);
+ memmap.map = NULL;
+ }
+}
+
+void __init efi_free_boot_services(void)
+{
+ void *p;
+
+ for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+ efi_memory_desc_t *md = p;
+ unsigned long long start = md->phys_addr;
+ unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
+
+ if (md->type != EFI_BOOT_SERVICES_CODE &&
+ md->type != EFI_BOOT_SERVICES_DATA)
+ continue;
+
+ /* Could not reserve boot area */
+ if (!size)
+ continue;
+
+ free_bootmem_late(start, size);
+ }
+
+ efi_unmap_memmap();
+}
+
+static int __init efi_systab_init(void *phys)
+{
+ if (efi_enabled(EFI_64BIT)) {
+ efi_system_table_64_t *systab64;
+ struct efi_setup_data *data = NULL;
+ u64 tmp = 0;
+
+ if (efi_setup) {
+ data = early_memremap(efi_setup, sizeof(*data));
+ if (!data)
+ return -ENOMEM;
+ }
+ systab64 = early_ioremap((unsigned long)phys,
+ sizeof(*systab64));
+ if (systab64 == NULL) {
+ pr_err("Couldn't map the system table!\n");
+ if (data)
+ early_iounmap(data, sizeof(*data));
+ return -ENOMEM;
+ }
+
+ efi_systab.hdr = systab64->hdr;
+ efi_systab.fw_vendor = data ? (unsigned long)data->fw_vendor :
+ systab64->fw_vendor;
+ tmp |= data ? data->fw_vendor : systab64->fw_vendor;
+ efi_systab.fw_revision = systab64->fw_revision;
+ efi_systab.con_in_handle = systab64->con_in_handle;
+ tmp |= systab64->con_in_handle;
+ efi_systab.con_in = systab64->con_in;
+ tmp |= systab64->con_in;
+ efi_systab.con_out_handle = systab64->con_out_handle;
+ tmp |= systab64->con_out_handle;
+ efi_systab.con_out = systab64->con_out;
+ tmp |= systab64->con_out;
+ efi_systab.stderr_handle = systab64->stderr_handle;
+ tmp |= systab64->stderr_handle;
+ efi_systab.stderr = systab64->stderr;
+ tmp |= systab64->stderr;
+ efi_systab.runtime = data ?
+ (void *)(unsigned long)data->runtime :
+ (void *)(unsigned long)systab64->runtime;
+ tmp |= data ? data->runtime : systab64->runtime;
+ efi_systab.boottime = (void *)(unsigned long)systab64->boottime;
+ tmp |= systab64->boottime;
+ efi_systab.nr_tables = systab64->nr_tables;
+ efi_systab.tables = data ? (unsigned long)data->tables :
+ systab64->tables;
+ tmp |= data ? data->tables : systab64->tables;
+
+ early_iounmap(systab64, sizeof(*systab64));
+ if (data)
+ early_iounmap(data, sizeof(*data));
+#ifdef CONFIG_X86_32
+ if (tmp >> 32) {
+ pr_err("EFI data located above 4GB, disabling EFI.\n");
+ return -EINVAL;
+ }
+#endif
+ } else {
+ efi_system_table_32_t *systab32;
+
+ systab32 = early_ioremap((unsigned long)phys,
+ sizeof(*systab32));
+ if (systab32 == NULL) {
+ pr_err("Couldn't map the system table!\n");
+ return -ENOMEM;
+ }
+
+ efi_systab.hdr = systab32->hdr;
+ efi_systab.fw_vendor = systab32->fw_vendor;
+ efi_systab.fw_revision = systab32->fw_revision;
+ efi_systab.con_in_handle = systab32->con_in_handle;
+ efi_systab.con_in = systab32->con_in;
+ efi_systab.con_out_handle = systab32->con_out_handle;
+ efi_systab.con_out = systab32->con_out;
+ efi_systab.stderr_handle = systab32->stderr_handle;
+ efi_systab.stderr = systab32->stderr;
+ efi_systab.runtime = (void *)(unsigned long)systab32->runtime;
+ efi_systab.boottime = (void *)(unsigned long)systab32->boottime;
+ efi_systab.nr_tables = systab32->nr_tables;
+ efi_systab.tables = systab32->tables;
+
+ early_iounmap(systab32, sizeof(*systab32));
+ }
+
+ efi.systab = &efi_systab;
+
+ /*
+ * Verify the EFI Table
+ */
+ if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
+ pr_err("System table signature incorrect!\n");
+ return -EINVAL;
+ }
+ if ((efi.systab->hdr.revision >> 16) == 0)
+ pr_err("Warning: System table version %d.%02d, expected 1.00 or greater!\n",
+ efi.systab->hdr.revision >> 16,
+ efi.systab->hdr.revision & 0xffff);
+
+ set_bit(EFI_SYSTEM_TABLES, &efi.flags);
+
+ return 0;
+}
+
+static int __init efi_runtime_init32(void)
+{
+ efi_runtime_services_32_t *runtime;
+
+ runtime = early_ioremap((unsigned long)efi.systab->runtime,
+ sizeof(efi_runtime_services_32_t));
+ if (!runtime) {
+ pr_err("Could not map the runtime service table!\n");
+ return -ENOMEM;
+ }
+
+ /*
+ * We will only need *early* access to the following two
+ * EFI runtime services before set_virtual_address_map
+ * is invoked.
+ */
+ efi_phys.set_virtual_address_map =
+ (efi_set_virtual_address_map_t *)
+ (unsigned long)runtime->set_virtual_address_map;
+ early_iounmap(runtime, sizeof(efi_runtime_services_32_t));
+
+ return 0;
+}
+
+static int __init efi_runtime_init64(void)
+{
+ efi_runtime_services_64_t *runtime;
+
+ runtime = early_ioremap((unsigned long)efi.systab->runtime,
+ sizeof(efi_runtime_services_64_t));
+ if (!runtime) {
+ pr_err("Could not map the runtime service table!\n");
+ return -ENOMEM;
+ }
+
+ /*
+ * We will only need *early* access to the following two
+ * EFI runtime services before set_virtual_address_map
+ * is invoked.
+ */
+ efi_phys.set_virtual_address_map =
+ (efi_set_virtual_address_map_t *)
+ (unsigned long)runtime->set_virtual_address_map;
+ early_iounmap(runtime, sizeof(efi_runtime_services_64_t));
+
+ return 0;
+}
+
+static int __init efi_runtime_init(void)
+{
+ int rv;
+
+ /*
+ * Check out the runtime services table. We need to map
+ * the runtime services table so that we can grab the physical
+ * address of several of the EFI runtime functions, needed to
+ * set the firmware into virtual mode.
+ */
+ if (efi_enabled(EFI_64BIT))
+ rv = efi_runtime_init64();
+ else
+ rv = efi_runtime_init32();
+
+ if (rv)
+ return rv;
+
+ set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+
+ return 0;
+}
+
+static int __init efi_memmap_init(void)
+{
+ /* Map the EFI memory map */
+ memmap.map = early_ioremap((unsigned long)memmap.phys_map,
+ memmap.nr_map * memmap.desc_size);
+ if (memmap.map == NULL) {
+ pr_err("Could not map the memory map!\n");
+ return -ENOMEM;
+ }
+ memmap.map_end = memmap.map + (memmap.nr_map * memmap.desc_size);
+
+ if (add_efi_memmap)
+ do_add_efi_memmap();
+
+ set_bit(EFI_MEMMAP, &efi.flags);
+
+ return 0;
+}
+
+/*
+ * A number of config table entries get remapped to virtual addresses
+ * after entering EFI virtual mode. However, the kexec kernel requires
+ * their physical addresses therefore we pass them via setup_data and
+ * correct those entries to their respective physical addresses here.
+ *
+ * Currently only handles smbios which is necessary for some firmware
+ * implementation.
+ */
+static int __init efi_reuse_config(u64 tables, int nr_tables)
+{
+ int i, sz, ret = 0;
+ void *p, *tablep;
+ struct efi_setup_data *data;
+
+ if (!efi_setup)
+ return 0;
+
+ if (!efi_enabled(EFI_64BIT))
+ return 0;
+
+ data = early_memremap(efi_setup, sizeof(*data));
+ if (!data) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (!data->smbios)
+ goto out_memremap;
+
+ sz = sizeof(efi_config_table_64_t);
+
+ p = tablep = early_memremap(tables, nr_tables * sz);
+ if (!p) {
+ pr_err("Could not map Configuration table!\n");
+ ret = -ENOMEM;
+ goto out_memremap;
+ }
+
+ for (i = 0; i < efi.systab->nr_tables; i++) {
+ efi_guid_t guid;
+
+ guid = ((efi_config_table_64_t *)p)->guid;
+
+ if (!efi_guidcmp(guid, SMBIOS_TABLE_GUID))
+ ((efi_config_table_64_t *)p)->table = data->smbios;
+ p += sz;
+ }
+ early_iounmap(tablep, nr_tables * sz);
+
+out_memremap:
+ early_iounmap(data, sizeof(*data));
+out:
+ return ret;
+}
+
+void __init efi_init(void)
+{
+ efi_char16_t *c16;
+ char vendor[100] = "unknown";
+ int i = 0;
+ void *tmp;
+
+#ifdef CONFIG_X86_32
+ if (boot_params.efi_info.efi_systab_hi ||
+ boot_params.efi_info.efi_memmap_hi) {
+ pr_info("Table located above 4GB, disabling EFI.\n");
+ return;
+ }
+ efi_phys.systab = (efi_system_table_t *)boot_params.efi_info.efi_systab;
+#else
+ efi_phys.systab = (efi_system_table_t *)
+ (boot_params.efi_info.efi_systab |
+ ((__u64)boot_params.efi_info.efi_systab_hi<<32));
+#endif
+
+ if (efi_systab_init(efi_phys.systab))
+ return;
+
+ set_bit(EFI_SYSTEM_TABLES, &efi.flags);
+
+ efi.config_table = (unsigned long)efi.systab->tables;
+ efi.fw_vendor = (unsigned long)efi.systab->fw_vendor;
+ efi.runtime = (unsigned long)efi.systab->runtime;
+
+ /*
+ * Show what we know for posterity
+ */
+ c16 = tmp = early_ioremap(efi.systab->fw_vendor, 2);
+ if (c16) {
+ for (i = 0; i < sizeof(vendor) - 1 && *c16; ++i)
+ vendor[i] = *c16++;
+ vendor[i] = '\0';
+ } else
+ pr_err("Could not map the firmware vendor!\n");
+ early_iounmap(tmp, 2);
+
+ pr_info("EFI v%u.%.02u by %s\n",
+ efi.systab->hdr.revision >> 16,
+ efi.systab->hdr.revision & 0xffff, vendor);
+
+ if (efi_reuse_config(efi.systab->tables, efi.systab->nr_tables))
+ return;
+
+ if (efi_config_init(arch_tables))
+ return;
+
+ /*
+ * Note: We currently don't support runtime services on an EFI
+ * that doesn't match the kernel 32/64-bit mode.
+ */
+
+ if (!efi_runtime_supported())
+ pr_info("No EFI runtime due to 32/64-bit mismatch with kernel\n");
+ else {
+ if (disable_runtime || efi_runtime_init())
+ return;
+ }
+ if (efi_memmap_init())
+ return;
+
+ set_bit(EFI_MEMMAP, &efi.flags);
+
+ print_efi_memmap();
+}
+
+void __init efi_late_init(void)
+{
+ efi_bgrt_init();
+}
+
+void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
+{
+ u64 addr, npages;
+
+ addr = md->virt_addr;
+ npages = md->num_pages;
+
+ memrange_efi_to_native(&addr, &npages);
+
+ if (executable)
+ set_memory_x(addr, npages);
+ else
+ set_memory_nx(addr, npages);
+}
+
+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)
+ continue;
+
+ efi_set_executable(md, true);
+ }
+}
+
+void efi_memory_uc(u64 addr, unsigned long size)
+{
+ unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
+ u64 npages;
+
+ npages = round_up(size, page_shift) / page_shift;
+ memrange_efi_to_native(&addr, &npages);
+ set_memory_uc(addr, npages);
+}
+
+void __init old_map_region(efi_memory_desc_t *md)
+{
+ u64 start_pfn, end_pfn, end;
+ unsigned long size;
+ void *va;
+
+ start_pfn = PFN_DOWN(md->phys_addr);
+ size = md->num_pages << PAGE_SHIFT;
+ end = md->phys_addr + size;
+ end_pfn = PFN_UP(end);
+
+ if (pfn_range_is_mapped(start_pfn, end_pfn)) {
+ va = __va(md->phys_addr);
+
+ if (!(md->attribute & EFI_MEMORY_WB))
+ efi_memory_uc((u64)(unsigned long)va, size);
+ } else
+ va = efi_ioremap(md->phys_addr, size,
+ md->type, md->attribute);
+
+ md->virt_addr = (u64) (unsigned long) va;
+ if (!va)
+ pr_err("ioremap of 0x%llX failed!\n",
+ (unsigned long long)md->phys_addr);
+}
+
+static void native_runtime_setup(void)
+{
+ efi.get_time = virt_efi_get_time;
+ efi.set_time = virt_efi_set_time;
+ efi.get_wakeup_time = virt_efi_get_wakeup_time;
+ efi.set_wakeup_time = virt_efi_set_wakeup_time;
+ efi.get_variable = virt_efi_get_variable;
+ efi.get_next_variable = virt_efi_get_next_variable;
+ efi.set_variable = virt_efi_set_variable;
+ efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
+ efi.reset_system = virt_efi_reset_system;
+ efi.query_variable_info = virt_efi_query_variable_info;
+ efi.update_capsule = virt_efi_update_capsule;
+ efi.query_capsule_caps = virt_efi_query_capsule_caps;
+}
+
+/* Merge contiguous regions of the same type and attribute */
+static void __init efi_merge_regions(void)
+{
+ void *p;
+ efi_memory_desc_t *md, *prev_md = NULL;
+
+ for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+ u64 prev_size;
+ md = p;
+
+ if (!prev_md) {
+ prev_md = md;
+ continue;
+ }
+
+ if (prev_md->type != md->type ||
+ prev_md->attribute != md->attribute) {
+ prev_md = md;
+ continue;
+ }
+
+ prev_size = prev_md->num_pages << EFI_PAGE_SHIFT;
+
+ if (md->phys_addr == (prev_md->phys_addr + prev_size)) {
+ prev_md->num_pages += md->num_pages;
+ md->type = EFI_RESERVED_TYPE;
+ md->attribute = 0;
+ continue;
+ }
+ prev_md = md;
+ }
+}
+
+static void __init get_systab_virt_addr(efi_memory_desc_t *md)
+{
+ unsigned long size;
+ u64 end, systab;
+
+ size = md->num_pages << EFI_PAGE_SHIFT;
+ end = md->phys_addr + size;
+ systab = (u64)(unsigned long)efi_phys.systab;
+ if (md->phys_addr <= systab && systab < end) {
+ systab += md->virt_addr - md->phys_addr;
+ efi.systab = (efi_system_table_t *)(unsigned long)systab;
+ }
+}
+
+static void __init save_runtime_map(void)
+{
+#ifdef CONFIG_KEXEC
+ efi_memory_desc_t *md;
+ void *tmp, *p, *q = NULL;
+ int count = 0;
+
+ if (efi_enabled(EFI_OLD_MEMMAP))
+ return;
+
+ for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+ md = p;
+
+ if (!(md->attribute & EFI_MEMORY_RUNTIME) ||
+ (md->type == EFI_BOOT_SERVICES_CODE) ||
+ (md->type == EFI_BOOT_SERVICES_DATA))
+ continue;
+ tmp = krealloc(q, (count + 1) * memmap.desc_size, GFP_KERNEL);
+ if (!tmp)
+ goto out;
+ q = tmp;
+
+ memcpy(q + count * memmap.desc_size, md, memmap.desc_size);
+ count++;
+ }
+
+ efi_runtime_map_setup(q, count, memmap.desc_size);
+ return;
+
+out:
+ kfree(q);
+ pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
+#endif
+}
+
+static void *realloc_pages(void *old_memmap, int old_shift)
+{
+ void *ret;
+
+ ret = (void *)__get_free_pages(GFP_KERNEL, old_shift + 1);
+ if (!ret)
+ goto out;
+
+ /*
+ * A first-time allocation doesn't have anything to copy.
+ */
+ if (!old_memmap)
+ return ret;
+
+ memcpy(ret, old_memmap, PAGE_SIZE << old_shift);
+
+out:
+ free_pages((unsigned long)old_memmap, old_shift);
+ return ret;
+}
+
+/*
+ * Map the efi memory ranges of the runtime services and update new_mmap with
+ * virtual addresses.
+ */
+static void * __init efi_map_regions(int *count, int *pg_shift)
+{
+ void *p, *new_memmap = NULL;
+ unsigned long left = 0;
+ efi_memory_desc_t *md;
+
+ for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+ md = p;
+ if (!(md->attribute & EFI_MEMORY_RUNTIME)) {
+#ifdef CONFIG_X86_64
+ if (md->type != EFI_BOOT_SERVICES_CODE &&
+ md->type != EFI_BOOT_SERVICES_DATA)
+#endif
+ continue;
+ }
+
+ efi_map_region(md);
+ get_systab_virt_addr(md);
+
+ if (left < memmap.desc_size) {
+ new_memmap = realloc_pages(new_memmap, *pg_shift);
+ if (!new_memmap)
+ return NULL;
+
+ left += PAGE_SIZE << *pg_shift;
+ (*pg_shift)++;
+ }
+
+ memcpy(new_memmap + (*count * memmap.desc_size), md,
+ memmap.desc_size);
+
+ left -= memmap.desc_size;
+ (*count)++;
+ }
+
+ return new_memmap;
+}
+
+static void __init kexec_enter_virtual_mode(void)
+{
+#ifdef CONFIG_KEXEC
+ efi_memory_desc_t *md;
+ void *p;
+
+ efi.systab = NULL;
+
+ /*
+ * We don't do virtual mode, since we don't do runtime services, on
+ * non-native EFI
+ */
+ if (!efi_is_native()) {
+ efi_unmap_memmap();
+ return;
+ }
+
+ /*
+ * Map efi regions which were passed via setup_data. The virt_addr is a
+ * fixed addr which was used in first kernel of a kexec boot.
+ */
+ for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+ md = p;
+ efi_map_region_fixed(md); /* FIXME: add error handling */
+ get_systab_virt_addr(md);
+ }
+
+ save_runtime_map();
+
+ BUG_ON(!efi.systab);
+
+ efi_sync_low_kernel_mappings();
+
+ /*
+ * Now that EFI is in virtual mode, update the function
+ * pointers in the runtime service table to the new virtual addresses.
+ *
+ * Call EFI services through wrapper functions.
+ */
+ efi.runtime_version = efi_systab.hdr.revision;
+
+ native_runtime_setup();
+
+ efi.set_virtual_address_map = NULL;
+
+ if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
+ runtime_code_page_mkexec();
+
+ /* clean DUMMY object */
+ efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
+ EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS,
+ 0, NULL);
+#endif
+}
+
+/*
+ * This function will switch the EFI runtime services to virtual mode.
+ * Essentially, we look through the EFI memmap and map every region that
+ * has the runtime attribute bit set in its memory descriptor into the
+ * ->trampoline_pgd page table using a top-down VA allocation scheme.
+ *
+ * The old method which used to update that memory descriptor with the
+ * virtual address obtained from ioremap() is still supported when the
+ * kernel is booted with efi=old_map on its command line. Same old
+ * method enabled the runtime services to be called without having to
+ * thunk back into physical mode for every invocation.
+ *
+ * The new method does a pagetable switch in a preemption-safe manner
+ * so that we're in a different address space when calling a runtime
+ * function. For function arguments passing we do copy the PGDs of the
+ * kernel page table into ->trampoline_pgd prior to each call.
+ *
+ * Specially for kexec boot, efi runtime maps in previous kernel should
+ * be passed in via setup_data. In that case runtime ranges will be mapped
+ * to the same virtual addresses as the first kernel, see
+ * kexec_enter_virtual_mode().
+ */
+static void __init __efi_enter_virtual_mode(void)
+{
+ int count = 0, pg_shift = 0;
+ void *new_memmap = NULL;
+ efi_status_t status;
+
+ efi.systab = NULL;
+
+ efi_merge_regions();
+ new_memmap = efi_map_regions(&count, &pg_shift);
+ if (!new_memmap) {
+ pr_err("Error reallocating memory, EFI runtime non-functional!\n");
+ return;
+ }
+
+ save_runtime_map();
+
+ BUG_ON(!efi.systab);
+
+ if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift))
+ return;
+
+ efi_sync_low_kernel_mappings();
+ efi_dump_pagetable();
+
+ if (efi_is_native()) {
+ status = phys_efi_set_virtual_address_map(
+ memmap.desc_size * count,
+ memmap.desc_size,
+ memmap.desc_version,
+ (efi_memory_desc_t *)__pa(new_memmap));
+ } else {
+ status = efi_thunk_set_virtual_address_map(
+ efi_phys.set_virtual_address_map,
+ memmap.desc_size * count,
+ memmap.desc_size,
+ memmap.desc_version,
+ (efi_memory_desc_t *)__pa(new_memmap));
+ }
+
+ if (status != EFI_SUCCESS) {
+ pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
+ status);
+ panic("EFI call to SetVirtualAddressMap() failed!");
+ }
+
+ /*
+ * Now that EFI is in virtual mode, update the function
+ * pointers in the runtime service table to the new virtual addresses.
+ *
+ * Call EFI services through wrapper functions.
+ */
+ efi.runtime_version = efi_systab.hdr.revision;
+
+ if (efi_is_native())
+ native_runtime_setup();
+ else
+ efi_thunk_runtime_setup();
+
+ efi.set_virtual_address_map = NULL;
+
+ efi_runtime_mkexec();
+
+ /*
+ * We mapped the descriptor array into the EFI pagetable above but we're
+ * not unmapping it here. Here's why:
+ *
+ * We're copying select PGDs from the kernel page table to the EFI page
+ * table and when we do so and make changes to those PGDs like unmapping
+ * stuff from them, those changes appear in the kernel page table and we
+ * go boom.
+ *
+ * From setup_real_mode():
+ *
+ * ...
+ * trampoline_pgd[0] = init_level4_pgt[pgd_index(__PAGE_OFFSET)].pgd;
+ *
+ * In this particular case, our allocation is in PGD 0 of the EFI page
+ * table but we've copied that PGD from PGD[272] of the EFI page table:
+ *
+ * pgd_index(__PAGE_OFFSET = 0xffff880000000000) = 272
+ *
+ * where the direct memory mapping in kernel space is.
+ *
+ * new_memmap's VA comes from that direct mapping and thus clearing it,
+ * it would get cleared in the kernel page table too.
+ *
+ * efi_cleanup_page_tables(__pa(new_memmap), 1 << pg_shift);
+ */
+ free_pages((unsigned long)new_memmap, pg_shift);
+
+ /* clean DUMMY object */
+ efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
+ EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS,
+ 0, NULL);
+}
+
+void __init efi_enter_virtual_mode(void)
+{
+ if (efi_setup)
+ kexec_enter_virtual_mode();
+ else
+ __efi_enter_virtual_mode();
+}
+
+/*
+ * Convenience functions to obtain memory types and attributes
+ */
+u32 efi_mem_type(unsigned long phys_addr)
+{
+ efi_memory_desc_t *md;
+ void *p;
+
+ if (!efi_enabled(EFI_MEMMAP))
+ return 0;
+
+ for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+ md = p;
+ if ((md->phys_addr <= phys_addr) &&
+ (phys_addr < (md->phys_addr +
+ (md->num_pages << EFI_PAGE_SHIFT))))
+ return md->type;
+ }
+ return 0;
+}
+
+u64 efi_mem_attributes(unsigned long phys_addr)
+{
+ efi_memory_desc_t *md;
+ void *p;
+
+ for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+ md = p;
+ if ((md->phys_addr <= phys_addr) &&
+ (phys_addr < (md->phys_addr +
+ (md->num_pages << EFI_PAGE_SHIFT))))
+ return md->attribute;
+ }
+ return 0;
+}
+
+/*
+ * Some firmware implementations refuse to boot if there's insufficient space
+ * in the variable store. Ensure that we never use more than a safe limit.
+ *
+ * Return EFI_SUCCESS if it is safe to write 'size' bytes to the variable
+ * store.
+ */
+efi_status_t efi_query_variable_store(u32 attributes, unsigned long size)
+{
+ efi_status_t status;
+ u64 storage_size, remaining_size, max_size;
+
+ if (!(attributes & EFI_VARIABLE_NON_VOLATILE))
+ return 0;
+
+ status = efi.query_variable_info(attributes, &storage_size,
+ &remaining_size, &max_size);
+ if (status != EFI_SUCCESS)
+ return status;
+
+ /*
+ * We account for that by refusing the write if permitting it would
+ * reduce the available space to under 5KB. This figure was provided by
+ * Samsung, so should be safe.
+ */
+ if ((remaining_size - size < EFI_MIN_RESERVE) &&
+ !efi_no_storage_paranoia) {
+
+ /*
+ * Triggering garbage collection may require that the firmware
+ * generate a real EFI_OUT_OF_RESOURCES error. We can force
+ * that by attempting to use more space than is available.
+ */
+ unsigned long dummy_size = remaining_size + 1024;
+ void *dummy = kzalloc(dummy_size, GFP_ATOMIC);
+
+ if (!dummy)
+ return EFI_OUT_OF_RESOURCES;
+
+ status = efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
+ EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS,
+ dummy_size, dummy);
+
+ if (status == EFI_SUCCESS) {
+ /*
+ * This should have failed, so if it didn't make sure
+ * that we delete it...
+ */
+ efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
+ EFI_VARIABLE_NON_VOLATILE |
+ EFI_VARIABLE_BOOTSERVICE_ACCESS |
+ EFI_VARIABLE_RUNTIME_ACCESS,
+ 0, dummy);
+ }
+
+ kfree(dummy);
+
+ /*
+ * The runtime code may now have triggered a garbage collection
+ * run, so check the variable info again
+ */
+ status = efi.query_variable_info(attributes, &storage_size,
+ &remaining_size, &max_size);
+
+ if (status != EFI_SUCCESS)
+ return status;
+
+ /*
+ * There still isn't enough room, so return an error
+ */
+ if (remaining_size - size < EFI_MIN_RESERVE)
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ return EFI_SUCCESS;
+}
+EXPORT_SYMBOL_GPL(efi_query_variable_store);
+
+static int __init parse_efi_cmdline(char *str)
+{
+ if (*str == '=')
+ str++;
+
+ if (!strncmp(str, "old_map", 7))
+ set_bit(EFI_OLD_MEMMAP, &efi.flags);
+
+ return 0;
+}
+early_param("efi", parse_efi_cmdline);
+
+void __init efi_apply_memmap_quirks(void)
+{
+ /*
+ * Once setup is done earlier, unmap the EFI memory map on mismatched
+ * firmware/kernel architectures since there is no support for runtime
+ * services.
+ */
+ if (!efi_runtime_supported()) {
+ pr_info("efi: Setup done, disabling due to 32/64-bit mismatch\n");
+ efi_unmap_memmap();
+ }
+
+ /*
+ * UV doesn't support the new EFI pagetable mapping yet.
+ */
+ if (is_uv_system())
+ set_bit(EFI_OLD_MEMMAP, &efi.flags);
+}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-09 14:52:05 +0000