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- // SPDX-License-Identifier: GPL-2.0
- /*
- * 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/e820/api.h>
- #include <asm/time.h>
- #include <asm/set_memory.h>
- #include <asm/tlbflush.h>
- #include <asm/x86_init.h>
- #include <asm/uv/uv.h>
- 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 int add_efi_memmap __initdata;
- 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 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;
- unsigned long flags;
- pgd_t *save_pgd;
- save_pgd = efi_call_phys_prolog();
- /* Disable interrupts around EFI calls: */
- local_irq_save(flags);
- status = efi_call_phys(efi_phys.set_virtual_address_map,
- memory_map_size, descriptor_size,
- descriptor_version, virtual_map);
- local_irq_restore(flags);
- efi_call_phys_epilog(save_pgd);
- return status;
- }
- void __init efi_find_mirror(void)
- {
- efi_memory_desc_t *md;
- u64 mirror_size = 0, total_size = 0;
- for_each_efi_memory_desc(md) {
- unsigned long long start = md->phys_addr;
- unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
- total_size += size;
- if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
- memblock_mark_mirror(start, size);
- mirror_size += size;
- }
- }
- if (mirror_size)
- pr_info("Memory: %lldM/%lldM mirrored memory\n",
- mirror_size>>20, total_size>>20);
- }
- /*
- * 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)
- {
- efi_memory_desc_t *md;
- for_each_efi_memory_desc(md) {
- 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_TYPE_RAM;
- else
- e820_type = E820_TYPE_RESERVED;
- break;
- case EFI_ACPI_RECLAIM_MEMORY:
- e820_type = E820_TYPE_ACPI;
- break;
- case EFI_ACPI_MEMORY_NVS:
- e820_type = E820_TYPE_NVS;
- break;
- case EFI_UNUSABLE_MEMORY:
- e820_type = E820_TYPE_UNUSABLE;
- break;
- case EFI_PERSISTENT_MEMORY:
- e820_type = E820_TYPE_PMEM;
- 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_TYPE_RESERVED;
- break;
- }
- e820__range_add(start, size, e820_type);
- }
- e820__update_table(e820_table);
- }
- int __init efi_memblock_x86_reserve_range(void)
- {
- struct efi_info *e = &boot_params.efi_info;
- struct efi_memory_map_data data;
- phys_addr_t pmap;
- int rv;
- if (efi_enabled(EFI_PARAVIRT))
- return 0;
- #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
- data.phys_map = pmap;
- data.size = e->efi_memmap_size;
- data.desc_size = e->efi_memdesc_size;
- data.desc_version = e->efi_memdesc_version;
- rv = efi_memmap_init_early(&data);
- if (rv)
- return rv;
- if (add_efi_memmap)
- do_add_efi_memmap();
- WARN(efi.memmap.desc_version != 1,
- "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
- efi.memmap.desc_version);
- memblock_reserve(pmap, efi.memmap.nr_map * efi.memmap.desc_size);
- return 0;
- }
- #define OVERFLOW_ADDR_SHIFT (64 - EFI_PAGE_SHIFT)
- #define OVERFLOW_ADDR_MASK (U64_MAX << OVERFLOW_ADDR_SHIFT)
- #define U64_HIGH_BIT (~(U64_MAX >> 1))
- static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i)
- {
- u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1;
- u64 end_hi = 0;
- char buf[64];
- if (md->num_pages == 0) {
- end = 0;
- } else if (md->num_pages > EFI_PAGES_MAX ||
- EFI_PAGES_MAX - md->num_pages <
- (md->phys_addr >> EFI_PAGE_SHIFT)) {
- end_hi = (md->num_pages & OVERFLOW_ADDR_MASK)
- >> OVERFLOW_ADDR_SHIFT;
- if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT))
- end_hi += 1;
- } else {
- return true;
- }
- pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n");
- if (end_hi) {
- pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n",
- i, efi_md_typeattr_format(buf, sizeof(buf), md),
- md->phys_addr, end_hi, end);
- } else {
- pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n",
- i, efi_md_typeattr_format(buf, sizeof(buf), md),
- md->phys_addr, end);
- }
- return false;
- }
- static void __init efi_clean_memmap(void)
- {
- efi_memory_desc_t *out = efi.memmap.map;
- const efi_memory_desc_t *in = out;
- const efi_memory_desc_t *end = efi.memmap.map_end;
- int i, n_removal;
- for (i = n_removal = 0; in < end; i++) {
- if (efi_memmap_entry_valid(in, i)) {
- if (out != in)
- memcpy(out, in, efi.memmap.desc_size);
- out = (void *)out + efi.memmap.desc_size;
- } else {
- n_removal++;
- }
- in = (void *)in + efi.memmap.desc_size;
- }
- if (n_removal > 0) {
- u64 size = efi.memmap.nr_map - n_removal;
- pr_warn("Removing %d invalid memory map entries.\n", n_removal);
- efi_memmap_install(efi.memmap.phys_map, size);
- }
- }
- void __init efi_print_memmap(void)
- {
- efi_memory_desc_t *md;
- int i = 0;
- for_each_efi_memory_desc(md) {
- char buf[64];
- pr_info("mem%02u: %s range=[0x%016llx-0x%016llx] (%lluMB)\n",
- i++, efi_md_typeattr_format(buf, sizeof(buf), md),
- md->phys_addr,
- md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1,
- (md->num_pages >> (20 - EFI_PAGE_SHIFT)));
- }
- }
- 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_memremap((unsigned long)phys,
- sizeof(*systab64));
- if (systab64 == NULL) {
- pr_err("Couldn't map the system table!\n");
- if (data)
- early_memunmap(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_memunmap(systab64, sizeof(*systab64));
- if (data)
- early_memunmap(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_memremap((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_memunmap(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);
- return 0;
- }
- static int __init efi_runtime_init32(void)
- {
- efi_runtime_services_32_t *runtime;
- runtime = early_memremap((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 SetVirtualAddressMap
- * EFI runtime service. All other runtime services will be called
- * via the virtual mapping.
- */
- efi_phys.set_virtual_address_map =
- (efi_set_virtual_address_map_t *)
- (unsigned long)runtime->set_virtual_address_map;
- early_memunmap(runtime, sizeof(efi_runtime_services_32_t));
- return 0;
- }
- static int __init efi_runtime_init64(void)
- {
- efi_runtime_services_64_t *runtime;
- runtime = early_memremap((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 SetVirtualAddressMap
- * EFI runtime service. All other runtime services will be called
- * via the virtual mapping.
- */
- efi_phys.set_virtual_address_map =
- (efi_set_virtual_address_map_t *)
- (unsigned long)runtime->set_virtual_address_map;
- early_memunmap(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.
- *
- * When EFI_PARAVIRT is in force then we could not map runtime
- * service memory region because we do not have direct access to it.
- * However, runtime services are available through proxy functions
- * (e.g. in case of Xen dom0 EFI implementation they call special
- * hypercall which executes relevant EFI functions) and that is why
- * they are always enabled.
- */
- if (!efi_enabled(EFI_PARAVIRT)) {
- 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;
- }
- 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;
- 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_memremap(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_memunmap(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 (efi_runtime_disabled() || efi_runtime_init()) {
- efi_memmap_unmap();
- return;
- }
- }
- efi_clean_memmap();
- if (efi_enabled(EFI_DBG))
- efi_print_memmap();
- }
- 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;
- /* Make EFI runtime service code area executable */
- for_each_efi_memory_desc(md) {
- if (md->type != EFI_RUNTIME_SERVICES_CODE)
- continue;
- efi_set_executable(md, true);
- }
- }
- void __init 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);
- }
- /* Merge contiguous regions of the same type and attribute */
- static void __init efi_merge_regions(void)
- {
- efi_memory_desc_t *md, *prev_md = NULL;
- for_each_efi_memory_desc(md) {
- u64 prev_size;
- 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 *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;
- }
- /*
- * Iterate the EFI memory map in reverse order because the regions
- * will be mapped top-down. The end result is the same as if we had
- * mapped things forward, but doesn't require us to change the
- * existing implementation of efi_map_region().
- */
- static inline void *efi_map_next_entry_reverse(void *entry)
- {
- /* Initial call */
- if (!entry)
- return efi.memmap.map_end - efi.memmap.desc_size;
- entry -= efi.memmap.desc_size;
- if (entry < efi.memmap.map)
- return NULL;
- return entry;
- }
- /*
- * efi_map_next_entry - Return the next EFI memory map descriptor
- * @entry: Previous EFI memory map descriptor
- *
- * This is a helper function to iterate over the EFI memory map, which
- * we do in different orders depending on the current configuration.
- *
- * To begin traversing the memory map @entry must be %NULL.
- *
- * Returns %NULL when we reach the end of the memory map.
- */
- static void *efi_map_next_entry(void *entry)
- {
- if (!efi_enabled(EFI_OLD_MEMMAP) && efi_enabled(EFI_64BIT)) {
- /*
- * Starting in UEFI v2.5 the EFI_PROPERTIES_TABLE
- * config table feature requires us to map all entries
- * in the same order as they appear in the EFI memory
- * map. That is to say, entry N must have a lower
- * virtual address than entry N+1. This is because the
- * firmware toolchain leaves relative references in
- * the code/data sections, which are split and become
- * separate EFI memory regions. Mapping things
- * out-of-order leads to the firmware accessing
- * unmapped addresses.
- *
- * Since we need to map things this way whether or not
- * the kernel actually makes use of
- * EFI_PROPERTIES_TABLE, let's just switch to this
- * scheme by default for 64-bit.
- */
- return efi_map_next_entry_reverse(entry);
- }
- /* Initial call */
- if (!entry)
- return efi.memmap.map;
- entry += efi.memmap.desc_size;
- if (entry >= efi.memmap.map_end)
- return NULL;
- return entry;
- }
- static bool should_map_region(efi_memory_desc_t *md)
- {
- /*
- * Runtime regions always require runtime mappings (obviously).
- */
- if (md->attribute & EFI_MEMORY_RUNTIME)
- return true;
- /*
- * 32-bit EFI doesn't suffer from the bug that requires us to
- * reserve boot services regions, and mixed mode support
- * doesn't exist for 32-bit kernels.
- */
- if (IS_ENABLED(CONFIG_X86_32))
- return false;
- /*
- * Map all of RAM so that we can access arguments in the 1:1
- * mapping when making EFI runtime calls.
- */
- if (IS_ENABLED(CONFIG_EFI_MIXED) && !efi_is_native()) {
- if (md->type == EFI_CONVENTIONAL_MEMORY ||
- md->type == EFI_LOADER_DATA ||
- md->type == EFI_LOADER_CODE)
- return true;
- }
- /*
- * Map boot services regions as a workaround for buggy
- * firmware that accesses them even when they shouldn't.
- *
- * See efi_{reserve,free}_boot_services().
- */
- if (md->type == EFI_BOOT_SERVICES_CODE ||
- md->type == EFI_BOOT_SERVICES_DATA)
- return true;
- return false;
- }
- /*
- * 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;
- unsigned long desc_size;
- efi_memory_desc_t *md;
- desc_size = efi.memmap.desc_size;
- p = NULL;
- while ((p = efi_map_next_entry(p))) {
- md = p;
- if (!should_map_region(md))
- continue;
- efi_map_region(md);
- get_systab_virt_addr(md);
- if (left < 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 * desc_size), md, desc_size);
- left -= desc_size;
- (*count)++;
- }
- return new_memmap;
- }
- static void __init kexec_enter_virtual_mode(void)
- {
- #ifdef CONFIG_KEXEC_CORE
- efi_memory_desc_t *md;
- unsigned int num_pages;
- efi.systab = NULL;
- /*
- * We don't do virtual mode, since we don't do runtime services, on
- * non-native EFI. With efi=old_map, we don't do runtime services in
- * kexec kernel because in the initial boot something else might
- * have been mapped at these virtual addresses.
- */
- if (!efi_is_native() || efi_enabled(EFI_OLD_MEMMAP)) {
- efi_memmap_unmap();
- clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
- return;
- }
- if (efi_alloc_page_tables()) {
- pr_err("Failed to allocate EFI page tables\n");
- clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
- 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_each_efi_memory_desc(md) {
- efi_map_region_fixed(md); /* FIXME: add error handling */
- get_systab_virt_addr(md);
- }
- /*
- * Unregister the early EFI memmap from efi_init() and install
- * the new EFI memory map.
- */
- efi_memmap_unmap();
- if (efi_memmap_init_late(efi.memmap.phys_map,
- efi.memmap.desc_size * efi.memmap.nr_map)) {
- pr_err("Failed to remap late EFI memory map\n");
- clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
- return;
- }
- BUG_ON(!efi.systab);
- num_pages = ALIGN(efi.memmap.nr_map * efi.memmap.desc_size, PAGE_SIZE);
- num_pages >>= PAGE_SHIFT;
- if (efi_setup_page_tables(efi.memmap.phys_map, num_pages)) {
- clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
- return;
- }
- 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;
- efi_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_delete_dummy_variable();
- #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
- * efi_pgd page table.
- *
- * 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 PUDs of the
- * kernel page table into efi_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;
- unsigned long pa;
- efi.systab = NULL;
- if (efi_alloc_page_tables()) {
- pr_err("Failed to allocate EFI page tables\n");
- clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
- return;
- }
- efi_merge_regions();
- new_memmap = efi_map_regions(&count, &pg_shift);
- if (!new_memmap) {
- pr_err("Error reallocating memory, EFI runtime non-functional!\n");
- clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
- return;
- }
- pa = __pa(new_memmap);
- /*
- * Unregister the early EFI memmap from efi_init() and install
- * the new EFI memory map that we are about to pass to the
- * firmware via SetVirtualAddressMap().
- */
- efi_memmap_unmap();
- if (efi_memmap_init_late(pa, efi.memmap.desc_size * count)) {
- pr_err("Failed to remap late EFI memory map\n");
- clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
- return;
- }
- if (efi_enabled(EFI_DBG)) {
- pr_info("EFI runtime memory map:\n");
- efi_print_memmap();
- }
- BUG_ON(!efi.systab);
- if (efi_setup_page_tables(pa, 1 << pg_shift)) {
- clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
- return;
- }
- efi_sync_low_kernel_mappings();
- if (efi_is_native()) {
- status = phys_efi_set_virtual_address_map(
- efi.memmap.desc_size * count,
- efi.memmap.desc_size,
- efi.memmap.desc_version,
- (efi_memory_desc_t *)pa);
- } else {
- status = efi_thunk_set_virtual_address_map(
- efi_phys.set_virtual_address_map,
- efi.memmap.desc_size * count,
- efi.memmap.desc_size,
- efi.memmap.desc_version,
- (efi_memory_desc_t *)pa);
- }
- 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())
- efi_native_runtime_setup();
- else
- efi_thunk_runtime_setup();
- efi.set_virtual_address_map = NULL;
- /*
- * Apply more restrictive page table mapping attributes now that
- * SVAM() has been called and the firmware has performed all
- * necessary relocation fixups for the new virtual addresses.
- */
- efi_runtime_update_mappings();
- /* clean DUMMY object */
- efi_delete_dummy_variable();
- }
- void __init efi_enter_virtual_mode(void)
- {
- if (efi_enabled(EFI_PARAVIRT))
- return;
- if (efi_setup)
- kexec_enter_virtual_mode();
- else
- __efi_enter_virtual_mode();
- efi_dump_pagetable();
- }
- static int __init arch_parse_efi_cmdline(char *str)
- {
- if (!str) {
- pr_warn("need at least one option\n");
- return -EINVAL;
- }
- if (parse_option_str(str, "old_map"))
- set_bit(EFI_OLD_MEMMAP, &efi.flags);
- return 0;
- }
- early_param("efi", arch_parse_efi_cmdline);
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