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UEFI 2.8 defines an EFI_MEMORY_SP attribute bit to augment the interpretation of the EFI Memory Types as "reserved for a specific purpose". The proposed Linux behavior for specific purpose memory is that it is reserved for direct-access (device-dax) by default and not available for any kernel usage, not even as an OOM fallback. Later, through udev scripts or another init mechanism, these device-dax claimed ranges can be reconfigured and hot-added to the available System-RAM with a unique node identifier. This device-dax management scheme implements "soft" in the "soft reserved" designation by allowing some or all of the reservation to be recovered as typical memory. This policy can be disabled at compile-time with CONFIG_EFI_SOFT_RESERVE=n, or runtime with efi=nosoftreserve. For this patch, update the ARM paths that consider EFI_CONVENTIONAL_MEMORY to optionally take the EFI_MEMORY_SP attribute into account as a reservation indicator. Publish the soft reservation as IORES_DESC_SOFT_RESERVED memory, similar to x86. (Based on an original patch by Ard) Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
291 lines
7.2 KiB
C
291 lines
7.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Extensible Firmware Interface
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*
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* Based on Extensible Firmware Interface Specification version 2.4
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*
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* Copyright (C) 2013 - 2015 Linaro Ltd.
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*/
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#define pr_fmt(fmt) "efi: " fmt
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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/mm_types.h>
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#include <linux/of.h>
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#include <linux/of_fdt.h>
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#include <linux/platform_device.h>
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#include <linux/screen_info.h>
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#include <asm/efi.h>
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u64 efi_system_table;
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static int __init is_memory(efi_memory_desc_t *md)
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{
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if (md->attribute & (EFI_MEMORY_WB|EFI_MEMORY_WT|EFI_MEMORY_WC))
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return 1;
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return 0;
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}
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/*
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* Translate a EFI virtual address into a physical address: this is necessary,
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* as some data members of the EFI system table are virtually remapped after
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* SetVirtualAddressMap() has been called.
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*/
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static phys_addr_t efi_to_phys(unsigned long addr)
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{
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efi_memory_desc_t *md;
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for_each_efi_memory_desc(md) {
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if (!(md->attribute & EFI_MEMORY_RUNTIME))
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continue;
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if (md->virt_addr == 0)
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/* no virtual mapping has been installed by the stub */
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break;
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if (md->virt_addr <= addr &&
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(addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
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return md->phys_addr + addr - md->virt_addr;
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}
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return addr;
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}
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static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;
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static __initdata efi_config_table_type_t arch_tables[] = {
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{LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, NULL, &screen_info_table},
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{NULL_GUID, NULL, NULL}
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};
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static void __init init_screen_info(void)
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{
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struct screen_info *si;
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if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
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si = early_memremap_ro(screen_info_table, sizeof(*si));
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if (!si) {
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pr_err("Could not map screen_info config table\n");
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return;
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}
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screen_info = *si;
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early_memunmap(si, sizeof(*si));
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/* dummycon on ARM needs non-zero values for columns/lines */
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screen_info.orig_video_cols = 80;
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screen_info.orig_video_lines = 25;
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}
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if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
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memblock_is_map_memory(screen_info.lfb_base))
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memblock_mark_nomap(screen_info.lfb_base, screen_info.lfb_size);
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}
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static int __init uefi_init(void)
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{
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efi_char16_t *c16;
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void *config_tables;
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size_t table_size;
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char vendor[100] = "unknown";
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int i, retval;
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efi.systab = early_memremap_ro(efi_system_table,
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sizeof(efi_system_table_t));
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if (efi.systab == NULL) {
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pr_warn("Unable to map EFI system table.\n");
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return -ENOMEM;
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}
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set_bit(EFI_BOOT, &efi.flags);
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if (IS_ENABLED(CONFIG_64BIT))
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set_bit(EFI_64BIT, &efi.flags);
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/*
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* Verify the EFI Table
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*/
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if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
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pr_err("System table signature incorrect\n");
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retval = -EINVAL;
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goto out;
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}
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if ((efi.systab->hdr.revision >> 16) < 2)
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pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
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efi.systab->hdr.revision >> 16,
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efi.systab->hdr.revision & 0xffff);
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efi.runtime_version = efi.systab->hdr.revision;
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/* Show what we know for posterity */
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c16 = early_memremap_ro(efi_to_phys(efi.systab->fw_vendor),
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sizeof(vendor) * sizeof(efi_char16_t));
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if (c16) {
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for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
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vendor[i] = c16[i];
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vendor[i] = '\0';
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early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
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}
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pr_info("EFI v%u.%.02u by %s\n",
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efi.systab->hdr.revision >> 16,
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efi.systab->hdr.revision & 0xffff, vendor);
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table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
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config_tables = early_memremap_ro(efi_to_phys(efi.systab->tables),
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table_size);
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if (config_tables == NULL) {
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pr_warn("Unable to map EFI config table array.\n");
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retval = -ENOMEM;
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goto out;
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}
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retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
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sizeof(efi_config_table_t),
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arch_tables);
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if (!retval)
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efi.config_table = (unsigned long)efi.systab->tables;
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early_memunmap(config_tables, table_size);
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out:
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early_memunmap(efi.systab, sizeof(efi_system_table_t));
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return retval;
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}
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/*
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* Return true for regions that can be used as System RAM.
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*/
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static __init int is_usable_memory(efi_memory_desc_t *md)
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{
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switch (md->type) {
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case EFI_LOADER_CODE:
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case EFI_LOADER_DATA:
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case EFI_ACPI_RECLAIM_MEMORY:
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case EFI_BOOT_SERVICES_CODE:
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case EFI_BOOT_SERVICES_DATA:
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case EFI_CONVENTIONAL_MEMORY:
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case EFI_PERSISTENT_MEMORY:
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/*
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* Special purpose memory is 'soft reserved', which means it
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* is set aside initially, but can be hotplugged back in or
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* be assigned to the dax driver after boot.
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*/
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if (efi_soft_reserve_enabled() &&
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(md->attribute & EFI_MEMORY_SP))
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return false;
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/*
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* According to the spec, these regions are no longer reserved
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* after calling ExitBootServices(). However, we can only use
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* them as System RAM if they can be mapped writeback cacheable.
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*/
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return (md->attribute & EFI_MEMORY_WB);
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default:
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break;
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}
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return false;
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}
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static __init void reserve_regions(void)
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{
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efi_memory_desc_t *md;
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u64 paddr, npages, size;
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if (efi_enabled(EFI_DBG))
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pr_info("Processing EFI memory map:\n");
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/*
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* Discard memblocks discovered so far: if there are any at this
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* point, they originate from memory nodes in the DT, and UEFI
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* uses its own memory map instead.
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*/
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memblock_dump_all();
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memblock_remove(0, PHYS_ADDR_MAX);
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for_each_efi_memory_desc(md) {
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paddr = md->phys_addr;
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npages = md->num_pages;
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if (efi_enabled(EFI_DBG)) {
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char buf[64];
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pr_info(" 0x%012llx-0x%012llx %s\n",
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paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
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efi_md_typeattr_format(buf, sizeof(buf), md));
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}
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memrange_efi_to_native(&paddr, &npages);
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size = npages << PAGE_SHIFT;
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if (is_memory(md)) {
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early_init_dt_add_memory_arch(paddr, size);
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if (!is_usable_memory(md))
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memblock_mark_nomap(paddr, size);
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/* keep ACPI reclaim memory intact for kexec etc. */
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if (md->type == EFI_ACPI_RECLAIM_MEMORY)
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memblock_reserve(paddr, size);
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}
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}
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}
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void __init efi_init(void)
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{
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struct efi_memory_map_data data;
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struct efi_fdt_params params;
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/* Grab UEFI information placed in FDT by stub */
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if (!efi_get_fdt_params(¶ms))
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return;
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efi_system_table = params.system_table;
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data.desc_version = params.desc_ver;
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data.desc_size = params.desc_size;
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data.size = params.mmap_size;
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data.phys_map = params.mmap;
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if (efi_memmap_init_early(&data) < 0) {
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/*
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* If we are booting via UEFI, the UEFI memory map is the only
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* description of memory we have, so there is little point in
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* proceeding if we cannot access it.
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*/
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panic("Unable to map EFI memory map.\n");
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}
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WARN(efi.memmap.desc_version != 1,
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"Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
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efi.memmap.desc_version);
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if (uefi_init() < 0) {
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efi_memmap_unmap();
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return;
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}
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reserve_regions();
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efi_esrt_init();
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memblock_reserve(params.mmap & PAGE_MASK,
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PAGE_ALIGN(params.mmap_size +
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(params.mmap & ~PAGE_MASK)));
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init_screen_info();
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/* ARM does not permit early mappings to persist across paging_init() */
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if (IS_ENABLED(CONFIG_ARM))
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efi_memmap_unmap();
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}
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static int __init register_gop_device(void)
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{
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void *pd;
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if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
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return 0;
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pd = platform_device_register_data(NULL, "efi-framebuffer", 0,
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&screen_info, sizeof(screen_info));
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return PTR_ERR_OR_ZERO(pd);
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}
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subsys_initcall(register_gop_device);
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