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path: root/drivers/firmware/efi/arm-init.c
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Diffstat (limited to 'drivers/firmware/efi/arm-init.c')
-rw-r--r--drivers/firmware/efi/arm-init.c209
1 files changed, 209 insertions, 0 deletions
diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c
new file mode 100644
index 000000000..9e15d571b
--- /dev/null
+++ b/drivers/firmware/efi/arm-init.c
@@ -0,0 +1,209 @@
+/*
+ * Extensible Firmware Interface
+ *
+ * Based on Extensible Firmware Interface Specification version 2.4
+ *
+ * Copyright (C) 2013 - 2015 Linaro Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/efi.h>
+#include <linux/init.h>
+#include <linux/memblock.h>
+#include <linux/mm_types.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+
+#include <asm/efi.h>
+
+struct efi_memory_map memmap;
+
+u64 efi_system_table;
+
+static int __init is_normal_ram(efi_memory_desc_t *md)
+{
+ if (md->attribute & EFI_MEMORY_WB)
+ 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 efi_to_phys(unsigned long addr)
+{
+ efi_memory_desc_t *md;
+
+ for_each_efi_memory_desc(&memmap, 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;
+}
+
+static int __init uefi_init(void)
+{
+ efi_char16_t *c16;
+ void *config_tables;
+ size_t table_size;
+ char vendor[100] = "unknown";
+ int i, retval;
+
+ efi.systab = early_memremap(efi_system_table,
+ sizeof(efi_system_table_t));
+ if (efi.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);
+
+ /*
+ * Verify the EFI Table
+ */
+ if (efi.systab->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
+ pr_err("System table signature incorrect\n");
+ retval = -EINVAL;
+ goto out;
+ }
+ if ((efi.systab->hdr.revision >> 16) < 2)
+ pr_warn("Warning: EFI system table version %d.%02d, expected 2.00 or greater\n",
+ efi.systab->hdr.revision >> 16,
+ efi.systab->hdr.revision & 0xffff);
+
+ /* Show what we know for posterity */
+ c16 = early_memremap(efi_to_phys(efi.systab->fw_vendor),
+ sizeof(vendor) * sizeof(efi_char16_t));
+ if (c16) {
+ for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
+ vendor[i] = c16[i];
+ vendor[i] = '\0';
+ early_memunmap(c16, sizeof(vendor) * sizeof(efi_char16_t));
+ }
+
+ pr_info("EFI v%u.%.02u by %s\n",
+ efi.systab->hdr.revision >> 16,
+ efi.systab->hdr.revision & 0xffff, vendor);
+
+ table_size = sizeof(efi_config_table_64_t) * efi.systab->nr_tables;
+ config_tables = early_memremap(efi_to_phys(efi.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, efi.systab->nr_tables,
+ sizeof(efi_config_table_t), NULL);
+
+ early_memunmap(config_tables, table_size);
+out:
+ early_memunmap(efi.systab, sizeof(efi_system_table_t));
+ return retval;
+}
+
+/*
+ * Return true for RAM regions we want to permanently reserve.
+ */
+static __init int is_reserve_region(efi_memory_desc_t *md)
+{
+ 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:
+ case EFI_PERSISTENT_MEMORY:
+ return 0;
+ default:
+ break;
+ }
+ return is_normal_ram(md);
+}
+
+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");
+
+ for_each_efi_memory_desc(&memmap, md) {
+ paddr = md->phys_addr;
+ npages = md->num_pages;
+
+ if (efi_enabled(EFI_DBG)) {
+ char buf[64];
+
+ pr_info(" 0x%012llx-0x%012llx %s",
+ 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_normal_ram(md))
+ early_init_dt_add_memory_arch(paddr, size);
+
+ if (is_reserve_region(md)) {
+ memblock_mark_nomap(paddr, size);
+ if (efi_enabled(EFI_DBG))
+ pr_cont("*");
+ }
+
+ if (efi_enabled(EFI_DBG))
+ pr_cont("\n");
+ }
+
+ set_bit(EFI_MEMMAP, &efi.flags);
+}
+
+void __init efi_init(void)
+{
+ struct efi_fdt_params params;
+
+ /* Grab UEFI information placed in FDT by stub */
+ if (!efi_get_fdt_params(&params))
+ return;
+
+ efi_system_table = params.system_table;
+
+ memmap.phys_map = params.mmap;
+ memmap.map = early_memremap(params.mmap, params.mmap_size);
+ if (memmap.map == NULL) {
+ /*
+ * 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");
+ }
+ memmap.map_end = memmap.map + params.mmap_size;
+ memmap.desc_size = params.desc_size;
+ memmap.desc_version = params.desc_ver;
+
+ if (uefi_init() < 0)
+ return;
+
+ reserve_regions();
+ early_memunmap(memmap.map, params.mmap_size);
+ memblock_mark_nomap(params.mmap & PAGE_MASK,
+ PAGE_ALIGN(params.mmap_size +
+ (params.mmap & ~PAGE_MASK)));
+}