5 files changed, 501 insertions, 0 deletions

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index e6e4d3749a6e..82e21de5db3b 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -280,6 +280,19 @@ config CMDLINE_FORCE
           This is useful if you cannot or don't want to change the
           command-line options your boot loader passes to the kernel.
 
+config EFI
+        bool "UEFI runtime support"
+        depends on OF && !CPU_BIG_ENDIAN
+        select LIBFDT
+        select UCS2_STRING
+        select EFI_PARAMS_FROM_FDT
+        default y
+        help
+          This option provides support for runtime services provided
+          by UEFI firmware (such as non-volatile variables, realtime
+          clock, and platform reset). This is only useful on systems
+          that have UEFI firmware.
+
 endmenu
 
 menu "Userspace binary formats"
@@ -333,6 +346,8 @@ source "net/Kconfig"
 
 source "drivers/Kconfig"
 
+source "drivers/firmware/Kconfig"
+
 source "fs/Kconfig"
 
 source "arch/arm64/kvm/Kconfig"
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
new file mode 100644
index 000000000000..5a46c4e7f539
--- /dev/null
+++ b/arch/arm64/include/asm/efi.h
@@ -0,0 +1,14 @@
+#ifndef _ASM_EFI_H
+#define _ASM_EFI_H
+
+#include <asm/io.h>
+
+#ifdef CONFIG_EFI
+extern void efi_init(void);
+extern void efi_idmap_init(void);
+#else
+#define efi_init()
+#define efi_idmap_init()
+#endif
+
+#endif /* _ASM_EFI_H */
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index 7d811d9522bc..f57ccd755886 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -22,6 +22,7 @@ arm64-obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND)   += sleep.o suspend.o
 arm64-obj-$(CONFIG_JUMP_LABEL)          += jump_label.o
 arm64-obj-$(CONFIG_KGDB)                += kgdb.o
+arm64-obj-$(CONFIG_EFI)                 += efi.o
 
 obj-y                                   += $(arm64-obj-y) vdso/
 obj-m                                   += $(arm64-obj-m)
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c
new file mode 100644
index 000000000000..7bfd65097210
--- /dev/null
+++ b/arch/arm64/kernel/efi.c
@@ -0,0 +1,466 @@
+/*
+ * Extensible Firmware Interface
+ *
+ * Based on Extensible Firmware Interface Specification version 2.4
+ *
+ * Copyright (C) 2013, 2014 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/export.h>
+#include <linux/memblock.h>
+#include <linux/bootmem.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include <asm/cacheflush.h>
+#include <asm/efi.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+
+struct efi_memory_map memmap;
+
+static efi_runtime_services_t *runtime;
+
+static u64 efi_system_table;
+
+static int uefi_debug __initdata;
+static int __init uefi_debug_setup(char *str)
+{
+        uefi_debug = 1;
+
+        return 0;
+}
+early_param("uefi_debug", uefi_debug_setup);
+
+static int __init is_normal_ram(efi_memory_desc_t *md)
+{
+        if (md->attribute & EFI_MEMORY_WB)
+                return 1;
+        return 0;
+}
+
+static void __init efi_setup_idmap(void)
+{
+        struct memblock_region *r;
+        efi_memory_desc_t *md;
+        u64 paddr, npages, size;
+
+        for_each_memblock(memory, r)
+                create_id_mapping(r->base, r->size, 0);
+
+        /* map runtime io spaces */
+        for_each_efi_memory_desc(&memmap, md) {
+                if (!(md->attribute & EFI_MEMORY_RUNTIME) || is_normal_ram(md))
+                        continue;
+                paddr = md->phys_addr;
+                npages = md->num_pages;
+                memrange_efi_to_native(&paddr, &npages);
+                size = npages << PAGE_SHIFT;
+                create_id_mapping(paddr, size, 1);
+        }
+}
+
+static int __init uefi_init(void)
+{
+        efi_char16_t *c16;
+        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);
+        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");
+                return -EINVAL;
+        }
+        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.systab->fw_vendor,
+                             sizeof(vendor));
+        if (c16) {
+                for (i = 0; i < (int) sizeof(vendor) - 1 && *c16; ++i)
+                        vendor[i] = c16[i];
+                vendor[i] = '\0';
+        }
+
+        pr_info("EFI v%u.%.02u by %s\n",
+                efi.systab->hdr.revision >> 16,
+                efi.systab->hdr.revision & 0xffff, vendor);
+
+        retval = efi_config_init(NULL);
+        if (retval == 0)
+                set_bit(EFI_CONFIG_TABLES, &efi.flags);
+
+        early_memunmap(c16, sizeof(vendor));
+        early_memunmap(efi.systab,  sizeof(efi_system_table_t));
+
+        return retval;
+}
+
+static __initdata char memory_type_name[][32] = {
+        {"Reserved"},
+        {"Loader Code"},
+        {"Loader Data"},
+        {"Boot Code"},
+        {"Boot Data"},
+        {"Runtime Code"},
+        {"Runtime Data"},
+        {"Conventional Memory"},
+        {"Unusable Memory"},
+        {"ACPI Reclaim Memory"},
+        {"ACPI Memory NVS"},
+        {"Memory Mapped I/O"},
+        {"MMIO Port Space"},
+        {"PAL Code"},
+};
+
+/*
+ * Return true for RAM regions we want to permanently reserve.
+ */
+static __init int is_reserve_region(efi_memory_desc_t *md)
+{
+        if (!is_normal_ram(md))
+                return 0;
+
+        if (md->attribute & EFI_MEMORY_RUNTIME)
+                return 1;
+
+        if (md->type == EFI_ACPI_RECLAIM_MEMORY ||
+            md->type == EFI_RESERVED_TYPE)
+                return 1;
+
+        return 0;
+}
+
+static __init void reserve_regions(void)
+{
+        efi_memory_desc_t *md;
+        u64 paddr, npages, size;
+
+        if (uefi_debug)
+                pr_info("Processing EFI memory map:\n");
+
+        for_each_efi_memory_desc(&memmap, md) {
+                paddr = md->phys_addr;
+                npages = md->num_pages;
+
+                if (uefi_debug)
+                        pr_info("  0x%012llx-0x%012llx [%s]",
+                                paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
+                                memory_type_name[md->type]);
+
+                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) ||
+                    md->type == EFI_BOOT_SERVICES_CODE ||
+                    md->type == EFI_BOOT_SERVICES_DATA) {
+                        memblock_reserve(paddr, size);
+                        if (uefi_debug)
+                                pr_cont("*");
+                }
+
+                if (uefi_debug)
+                        pr_cont("\n");
+        }
+}
+
+
+static u64 __init free_one_region(u64 start, u64 end)
+{
+        u64 size = end - start;
+
+        if (uefi_debug)
+                pr_info("  EFI freeing: 0x%012llx-0x%012llx\n", start, end - 1);
+
+        free_bootmem_late(start, size);
+        return size;
+}
+
+static u64 __init free_region(u64 start, u64 end)
+{
+        u64 map_start, map_end, total = 0;
+
+        if (end <= start)
+                return total;
+
+        map_start = (u64)memmap.phys_map;
+        map_end = PAGE_ALIGN(map_start + (memmap.map_end - memmap.map));
+        map_start &= PAGE_MASK;
+
+        if (start < map_end && end > map_start) {
+                /* region overlaps UEFI memmap */
+                if (start < map_start)
+                        total += free_one_region(start, map_start);
+
+                if (map_end < end)
+                        total += free_one_region(map_end, end);
+        } else
+                total += free_one_region(start, end);
+
+        return total;
+}
+
+static void __init free_boot_services(void)
+{
+        u64 total_freed = 0;
+        u64 keep_end, free_start, free_end;
+        efi_memory_desc_t *md;
+
+        /*
+         * If kernel uses larger pages than UEFI, we have to be careful
+         * not to inadvertantly free memory we want to keep if there is
+         * overlap at the kernel page size alignment. We do not want to
+         * free is_reserve_region() memory nor the UEFI memmap itself.
+         *
+         * The memory map is sorted, so we keep track of the end of
+         * any previous region we want to keep, remember any region
+         * we want to free and defer freeing it until we encounter
+         * the next region we want to keep. This way, before freeing
+         * it, we can clip it as needed to avoid freeing memory we
+         * want to keep for UEFI.
+         */
+
+        keep_end = 0;
+        free_start = 0;
+
+        for_each_efi_memory_desc(&memmap, md) {
+                u64 paddr, npages, size;
+
+                if (is_reserve_region(md)) {
+                        /*
+                         * We don't want to free any memory from this region.
+                         */
+                        if (free_start) {
+                                /* adjust free_end then free region */
+                                if (free_end > md->phys_addr)
+                                        free_end -= PAGE_SIZE;
+                                total_freed += free_region(free_start, free_end);
+                                free_start = 0;
+                        }
+                        keep_end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
+                        continue;
+                }
+
+                if (md->type != EFI_BOOT_SERVICES_CODE &&
+                    md->type != EFI_BOOT_SERVICES_DATA) {
+                        /* no need to free this region */
+                        continue;
+                }
+
+                /*
+                 * We want to free memory from this region.
+                 */
+                paddr = md->phys_addr;
+                npages = md->num_pages;
+                memrange_efi_to_native(&paddr, &npages);
+                size = npages << PAGE_SHIFT;
+
+                if (free_start) {
+                        if (paddr <= free_end)
+                                free_end = paddr + size;
+                        else {
+                                total_freed += free_region(free_start, free_end);
+                                free_start = paddr;
+                                free_end = paddr + size;
+                        }
+                } else {
+                        free_start = paddr;
+                        free_end = paddr + size;
+                }
+                if (free_start < keep_end) {
+                        free_start += PAGE_SIZE;
+                        if (free_start >= free_end)
+                                free_start = 0;
+                }
+        }
+        if (free_start)
+                total_freed += free_region(free_start, free_end);
+
+        if (total_freed)
+                pr_info("Freed 0x%llx bytes of EFI boot services memory",
+                        total_freed);
+}
+
+void __init efi_init(void)
+{
+        struct efi_fdt_params params;
+
+        /* Grab UEFI information placed in FDT by stub */
+        if (!efi_get_fdt_params(&params, uefi_debug))
+                return;
+
+        efi_system_table = params.system_table;
+
+        memblock_reserve(params.mmap & PAGE_MASK,
+                         PAGE_ALIGN(params.mmap_size + (params.mmap & ~PAGE_MASK)));
+        memmap.phys_map = (void *)params.mmap;
+        memmap.map = early_memremap(params.mmap, params.mmap_size);
+        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();
+}
+
+void __init efi_idmap_init(void)
+{
+        /* boot time idmap_pg_dir is incomplete, so fill in missing parts */
+        efi_setup_idmap();
+}
+
+static int __init remap_region(efi_memory_desc_t *md, void **new)
+{
+        u64 paddr, vaddr, npages, size;
+
+        paddr = md->phys_addr;
+        npages = md->num_pages;
+        memrange_efi_to_native(&paddr, &npages);
+        size = npages << PAGE_SHIFT;
+
+        if (is_normal_ram(md))
+                vaddr = (__force u64)ioremap_cache(paddr, size);
+        else
+                vaddr = (__force u64)ioremap(paddr, size);
+
+        if (!vaddr) {
+                pr_err("Unable to remap 0x%llx pages @ %p\n",
+                       npages, (void *)paddr);
+                return 0;
+        }
+
+        /* adjust for any rounding when EFI and system pagesize differs */
+        md->virt_addr = vaddr + (md->phys_addr - paddr);
+
+        if (uefi_debug)
+                pr_info("  EFI remap 0x%012llx => %p\n",
+                        md->phys_addr, (void *)md->virt_addr);
+
+        memcpy(*new, md, memmap.desc_size);
+        *new += memmap.desc_size;
+
+        return 1;
+}
+
+/*
+ * Switch UEFI from an identity map to a kernel virtual map
+ */
+static int __init arm64_enter_virtual_mode(void)
+{
+        efi_memory_desc_t *md;
+        phys_addr_t virtmap_phys;
+        void *virtmap, *virt_md;
+        efi_status_t status;
+        u64 mapsize;
+        int count = 0;
+        unsigned long flags;
+
+        if (!efi_enabled(EFI_BOOT)) {
+                pr_info("EFI services will not be available.\n");
+                return -1;
+        }
+
+        pr_info("Remapping and enabling EFI services.\n");
+
+        /* replace early memmap mapping with permanent mapping */
+        mapsize = memmap.map_end - memmap.map;
+        early_memunmap(memmap.map, mapsize);
+        memmap.map = (__force void *)ioremap_cache((phys_addr_t)memmap.phys_map,
+                                                   mapsize);
+        memmap.map_end = memmap.map + mapsize;
+
+        efi.memmap = &memmap;
+
+        /* Map the runtime regions */
+        virtmap = kmalloc(mapsize, GFP_KERNEL);
+        if (!virtmap) {
+                pr_err("Failed to allocate EFI virtual memmap\n");
+                return -1;
+        }
+        virtmap_phys = virt_to_phys(virtmap);
+        virt_md = virtmap;
+
+        for_each_efi_memory_desc(&memmap, md) {
+                if (!(md->attribute & EFI_MEMORY_RUNTIME))
+                        continue;
+                if (remap_region(md, &virt_md))
+                        ++count;
+        }
+
+        efi.systab = (__force void *)efi_lookup_mapped_addr(efi_system_table);
+        if (efi.systab)
+                set_bit(EFI_SYSTEM_TABLES, &efi.flags);
+
+        local_irq_save(flags);
+        cpu_switch_mm(idmap_pg_dir, &init_mm);
+
+        /* Call SetVirtualAddressMap with the physical address of the map */
+        runtime = efi.systab->runtime;
+        efi.set_virtual_address_map = runtime->set_virtual_address_map;
+
+        status = efi.set_virtual_address_map(count * memmap.desc_size,
+                                             memmap.desc_size,
+                                             memmap.desc_version,
+                                             (efi_memory_desc_t *)virtmap_phys);
+        cpu_set_reserved_ttbr0();
+        flush_tlb_all();
+        local_irq_restore(flags);
+
+        kfree(virtmap);
+
+        free_boot_services();
+
+        if (status != EFI_SUCCESS) {
+                pr_err("Failed to set EFI virtual address map! [%lx]\n",
+                        status);
+                return -1;
+        }
+
+        /* Set up runtime services function pointers */
+        runtime = efi.systab->runtime;
+        efi.get_time = runtime->get_time;
+        efi.set_time = runtime->set_time;
+        efi.get_wakeup_time = runtime->get_wakeup_time;
+        efi.set_wakeup_time = runtime->set_wakeup_time;
+        efi.get_variable = runtime->get_variable;
+        efi.get_next_variable = runtime->get_next_variable;
+        efi.set_variable = runtime->set_variable;
+        efi.query_variable_info = runtime->query_variable_info;
+        efi.update_capsule = runtime->update_capsule;
+        efi.query_capsule_caps = runtime->query_capsule_caps;
+        efi.get_next_high_mono_count = runtime->get_next_high_mono_count;
+        efi.reset_system = runtime->reset_system;
+
+        set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
+
+        return 0;
+}
+early_initcall(arm64_enter_virtual_mode);
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 720853f70b6b..0a14aaffc834 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -41,6 +41,7 @@
 #include <linux/memblock.h>
 #include <linux/of_fdt.h>
 #include <linux/of_platform.h>
+#include <linux/efi.h>
 
 #include <asm/fixmap.h>
 #include <asm/cputype.h>
@@ -55,6 +56,7 @@
 #include <asm/traps.h>
 #include <asm/memblock.h>
 #include <asm/psci.h>
+#include <asm/efi.h>
 
 unsigned int processor_id;
 EXPORT_SYMBOL(processor_id);
@@ -366,11 +368,14 @@ void __init setup_arch(char **cmdline_p)
 
         parse_early_param();
 
+        efi_init();
         arm64_memblock_init();
 
         paging_init();
         request_standard_resources();
 
+        efi_idmap_init();
+
         unflatten_device_tree();
 
         psci_init();