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path: root/drivers/firmware/efi/efi-init.c
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-rw-r--r--drivers/firmware/efi/efi-init.c226
1 files changed, 226 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi-init.c b/drivers/firmware/efi/efi-init.c
new file mode 100644
index 000000000..2fd770b49
--- /dev/null
+++ b/drivers/firmware/efi/efi-init.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Extensible Firmware Interface
+ *
+ * Based on Extensible Firmware Interface Specification version 2.4
+ *
+ * Copyright (C) 2013 - 2015 Linaro Ltd.
+ */
+
+#define pr_fmt(fmt) "efi: " fmt
+
+#include <linux/efi.h>
+#include <linux/fwnode.h>
+#include <linux/init.h>
+#include <linux/memblock.h>
+#include <linux/mm_types.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_fdt.h>
+#include <linux/platform_device.h>
+#include <linux/screen_info.h>
+
+#include <asm/efi.h>
+
+static int __init is_memory(efi_memory_desc_t *md)
+{
+ if (md->attribute & (EFI_MEMORY_WB|EFI_MEMORY_WT|EFI_MEMORY_WC))
+ return 1;
+ return 0;
+}
+
+/*
+ * Translate a EFI virtual address into a physical address: this is necessary,
+ * as some data members of the EFI system table are virtually remapped after
+ * SetVirtualAddressMap() has been called.
+ */
+static phys_addr_t __init efi_to_phys(unsigned long addr)
+{
+ efi_memory_desc_t *md;
+
+ for_each_efi_memory_desc(md) {
+ if (!(md->attribute & EFI_MEMORY_RUNTIME))
+ continue;
+ if (md->virt_addr == 0)
+ /* no virtual mapping has been installed by the stub */
+ break;
+ if (md->virt_addr <= addr &&
+ (addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
+ return md->phys_addr + addr - md->virt_addr;
+ }
+ return addr;
+}
+
+extern __weak const efi_config_table_type_t efi_arch_tables[];
+
+static void __init init_screen_info(void)
+{
+ if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
+ memblock_is_map_memory(screen_info.lfb_base))
+ memblock_mark_nomap(screen_info.lfb_base, screen_info.lfb_size);
+}
+
+static int __init uefi_init(u64 efi_system_table)
+{
+ efi_config_table_t *config_tables;
+ efi_system_table_t *systab;
+ size_t table_size;
+ int retval;
+
+ systab = early_memremap_ro(efi_system_table, sizeof(efi_system_table_t));
+ if (systab == NULL) {
+ pr_warn("Unable to map EFI system table.\n");
+ return -ENOMEM;
+ }
+
+ set_bit(EFI_BOOT, &efi.flags);
+ if (IS_ENABLED(CONFIG_64BIT))
+ set_bit(EFI_64BIT, &efi.flags);
+
+ retval = efi_systab_check_header(&systab->hdr, 2);
+ if (retval)
+ goto out;
+
+ efi.runtime = systab->runtime;
+ efi.runtime_version = systab->hdr.revision;
+
+ efi_systab_report_header(&systab->hdr, efi_to_phys(systab->fw_vendor));
+
+ table_size = sizeof(efi_config_table_t) * systab->nr_tables;
+ config_tables = early_memremap_ro(efi_to_phys(systab->tables),
+ table_size);
+ if (config_tables == NULL) {
+ pr_warn("Unable to map EFI config table array.\n");
+ retval = -ENOMEM;
+ goto out;
+ }
+ retval = efi_config_parse_tables(config_tables, systab->nr_tables,
+ efi_arch_tables);
+
+ early_memunmap(config_tables, table_size);
+out:
+ early_memunmap(systab, sizeof(efi_system_table_t));
+ return retval;
+}
+
+/*
+ * Return true for regions that can be used as System RAM.
+ */
+static __init int is_usable_memory(efi_memory_desc_t *md)
+{
+ switch (md->type) {
+ case EFI_LOADER_CODE:
+ case EFI_LOADER_DATA:
+ case EFI_ACPI_RECLAIM_MEMORY:
+ case EFI_BOOT_SERVICES_CODE:
+ case EFI_BOOT_SERVICES_DATA:
+ case EFI_CONVENTIONAL_MEMORY:
+ case EFI_PERSISTENT_MEMORY:
+ /*
+ * Special purpose memory is 'soft reserved', which means it
+ * is set aside initially, but can be hotplugged back in or
+ * be assigned to the dax driver after boot.
+ */
+ if (efi_soft_reserve_enabled() &&
+ (md->attribute & EFI_MEMORY_SP))
+ return false;
+
+ /*
+ * According to the spec, these regions are no longer reserved
+ * after calling ExitBootServices(). However, we can only use
+ * them as System RAM if they can be mapped writeback cacheable.
+ */
+ return (md->attribute & EFI_MEMORY_WB);
+ default:
+ break;
+ }
+ return false;
+}
+
+static __init void reserve_regions(void)
+{
+ efi_memory_desc_t *md;
+ u64 paddr, npages, size;
+
+ if (efi_enabled(EFI_DBG))
+ pr_info("Processing EFI memory map:\n");
+
+ /*
+ * Discard memblocks discovered so far: if there are any at this
+ * point, they originate from memory nodes in the DT, and UEFI
+ * uses its own memory map instead.
+ */
+ memblock_dump_all();
+ memblock_remove(0, PHYS_ADDR_MAX);
+
+ for_each_efi_memory_desc(md) {
+ paddr = md->phys_addr;
+ npages = md->num_pages;
+
+ if (efi_enabled(EFI_DBG)) {
+ char buf[64];
+
+ pr_info(" 0x%012llx-0x%012llx %s\n",
+ paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
+ efi_md_typeattr_format(buf, sizeof(buf), md));
+ }
+
+ memrange_efi_to_native(&paddr, &npages);
+ size = npages << PAGE_SHIFT;
+
+ if (is_memory(md)) {
+ early_init_dt_add_memory_arch(paddr, size);
+
+ if (!is_usable_memory(md))
+ memblock_mark_nomap(paddr, size);
+
+ /* keep ACPI reclaim memory intact for kexec etc. */
+ if (md->type == EFI_ACPI_RECLAIM_MEMORY)
+ memblock_reserve(paddr, size);
+ }
+ }
+}
+
+void __init efi_init(void)
+{
+ struct efi_memory_map_data data;
+ u64 efi_system_table;
+
+ /* Grab UEFI information placed in FDT by stub */
+ efi_system_table = efi_get_fdt_params(&data);
+ if (!efi_system_table)
+ return;
+
+ if (efi_memmap_init_early(&data) < 0) {
+ /*
+ * If we are booting via UEFI, the UEFI memory map is the only
+ * description of memory we have, so there is little point in
+ * proceeding if we cannot access it.
+ */
+ panic("Unable to map EFI memory map.\n");
+ }
+
+ WARN(efi.memmap.desc_version != 1,
+ "Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
+ efi.memmap.desc_version);
+
+ if (uefi_init(efi_system_table) < 0) {
+ efi_memmap_unmap();
+ return;
+ }
+
+ reserve_regions();
+ /*
+ * For memblock manipulation, the cap should come after the memblock_add().
+ * And now, memblock is fully populated, it is time to do capping.
+ */
+ early_init_dt_check_for_usable_mem_range();
+ efi_find_mirror();
+ efi_esrt_init();
+ efi_mokvar_table_init();
+
+ memblock_reserve(data.phys_map & PAGE_MASK,
+ PAGE_ALIGN(data.size + (data.phys_map & ~PAGE_MASK)));
+
+ init_screen_info();
+}