v4.19.13 snapshot.
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
new file mode 100644
index 0000000..6920033
--- /dev/null
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -0,0 +1,374 @@
+/*
+ * EFI stub implementation that is shared by arm and arm64 architectures.
+ * This should be #included by the EFI stub implementation files.
+ *
+ * Copyright (C) 2013,2014 Linaro Limited
+ * Roy Franz <roy.franz@linaro.org
+ * Copyright (C) 2013 Red Hat, Inc.
+ * Mark Salter <msalter@redhat.com>
+ *
+ * This file is part of the Linux kernel, and is made available under the
+ * terms of the GNU General Public License version 2.
+ *
+ */
+
+#include <linux/efi.h>
+#include <linux/sort.h>
+#include <asm/efi.h>
+
+#include "efistub.h"
+
+/*
+ * This is the base address at which to start allocating virtual memory ranges
+ * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use
+ * any allocation we choose, and eliminate the risk of a conflict after kexec.
+ * The value chosen is the largest non-zero power of 2 suitable for this purpose
+ * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can
+ * be mapped efficiently.
+ * Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split,
+ * map everything below 1 GB. (512 MB is a reasonable upper bound for the
+ * entire footprint of the UEFI runtime services memory regions)
+ */
+#define EFI_RT_VIRTUAL_BASE SZ_512M
+#define EFI_RT_VIRTUAL_SIZE SZ_512M
+
+#ifdef CONFIG_ARM64
+# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE_64
+#else
+# define EFI_RT_VIRTUAL_LIMIT TASK_SIZE
+#endif
+
+static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;
+
+void efi_char16_printk(efi_system_table_t *sys_table_arg,
+ efi_char16_t *str)
+{
+ struct efi_simple_text_output_protocol *out;
+
+ out = (struct efi_simple_text_output_protocol *)sys_table_arg->con_out;
+ out->output_string(out, str);
+}
+
+static struct screen_info *setup_graphics(efi_system_table_t *sys_table_arg)
+{
+ efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
+ efi_status_t status;
+ unsigned long size;
+ void **gop_handle = NULL;
+ struct screen_info *si = NULL;
+
+ size = 0;
+ status = efi_call_early(locate_handle, EFI_LOCATE_BY_PROTOCOL,
+ &gop_proto, NULL, &size, gop_handle);
+ if (status == EFI_BUFFER_TOO_SMALL) {
+ si = alloc_screen_info(sys_table_arg);
+ if (!si)
+ return NULL;
+ efi_setup_gop(sys_table_arg, si, &gop_proto, size);
+ }
+ return si;
+}
+
+/*
+ * This function handles the architcture specific differences between arm and
+ * arm64 regarding where the kernel image must be loaded and any memory that
+ * must be reserved. On failure it is required to free all
+ * all allocations it has made.
+ */
+efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
+ unsigned long *image_addr,
+ unsigned long *image_size,
+ unsigned long *reserve_addr,
+ unsigned long *reserve_size,
+ unsigned long dram_base,
+ efi_loaded_image_t *image);
+/*
+ * EFI entry point for the arm/arm64 EFI stubs. This is the entrypoint
+ * that is described in the PE/COFF header. Most of the code is the same
+ * for both archictectures, with the arch-specific code provided in the
+ * handle_kernel_image() function.
+ */
+unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
+ unsigned long *image_addr)
+{
+ efi_loaded_image_t *image;
+ efi_status_t status;
+ unsigned long image_size = 0;
+ unsigned long dram_base;
+ /* addr/point and size pairs for memory management*/
+ unsigned long initrd_addr;
+ u64 initrd_size = 0;
+ unsigned long fdt_addr = 0; /* Original DTB */
+ unsigned long fdt_size = 0;
+ char *cmdline_ptr = NULL;
+ int cmdline_size = 0;
+ unsigned long new_fdt_addr;
+ efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
+ unsigned long reserve_addr = 0;
+ unsigned long reserve_size = 0;
+ enum efi_secureboot_mode secure_boot;
+ struct screen_info *si;
+
+ /* Check if we were booted by the EFI firmware */
+ if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
+ goto fail;
+
+ status = check_platform_features(sys_table);
+ if (status != EFI_SUCCESS)
+ goto fail;
+
+ /*
+ * Get a handle to the loaded image protocol. This is used to get
+ * information about the running image, such as size and the command
+ * line.
+ */
+ status = sys_table->boottime->handle_protocol(handle,
+ &loaded_image_proto, (void *)&image);
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table, "Failed to get loaded image protocol\n");
+ goto fail;
+ }
+
+ dram_base = get_dram_base(sys_table);
+ if (dram_base == EFI_ERROR) {
+ pr_efi_err(sys_table, "Failed to find DRAM base\n");
+ goto fail;
+ }
+
+ /*
+ * Get the command line from EFI, using the LOADED_IMAGE
+ * protocol. We are going to copy the command line into the
+ * device tree, so this can be allocated anywhere.
+ */
+ cmdline_ptr = efi_convert_cmdline(sys_table, image, &cmdline_size);
+ if (!cmdline_ptr) {
+ pr_efi_err(sys_table, "getting command line via LOADED_IMAGE_PROTOCOL\n");
+ goto fail;
+ }
+
+ if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
+ IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
+ cmdline_size == 0)
+ efi_parse_options(CONFIG_CMDLINE);
+
+ if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0)
+ efi_parse_options(cmdline_ptr);
+
+ pr_efi(sys_table, "Booting Linux Kernel...\n");
+
+ si = setup_graphics(sys_table);
+
+ status = handle_kernel_image(sys_table, image_addr, &image_size,
+ &reserve_addr,
+ &reserve_size,
+ dram_base, image);
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table, "Failed to relocate kernel\n");
+ goto fail_free_cmdline;
+ }
+
+ /* Ask the firmware to clear memory on unclean shutdown */
+ efi_enable_reset_attack_mitigation(sys_table);
+
+ secure_boot = efi_get_secureboot(sys_table);
+
+ /*
+ * Unauthenticated device tree data is a security hazard, so ignore
+ * 'dtb=' unless UEFI Secure Boot is disabled. We assume that secure
+ * boot is enabled if we can't determine its state.
+ */
+ if (!IS_ENABLED(CONFIG_EFI_ARMSTUB_DTB_LOADER) ||
+ secure_boot != efi_secureboot_mode_disabled) {
+ if (strstr(cmdline_ptr, "dtb="))
+ pr_efi(sys_table, "Ignoring DTB from command line.\n");
+ } else {
+ status = handle_cmdline_files(sys_table, image, cmdline_ptr,
+ "dtb=",
+ ~0UL, &fdt_addr, &fdt_size);
+
+ if (status != EFI_SUCCESS) {
+ pr_efi_err(sys_table, "Failed to load device tree!\n");
+ goto fail_free_image;
+ }
+ }
+
+ if (fdt_addr) {
+ pr_efi(sys_table, "Using DTB from command line\n");
+ } else {
+ /* Look for a device tree configuration table entry. */
+ fdt_addr = (uintptr_t)get_fdt(sys_table, &fdt_size);
+ if (fdt_addr)
+ pr_efi(sys_table, "Using DTB from configuration table\n");
+ }
+
+ if (!fdt_addr)
+ pr_efi(sys_table, "Generating empty DTB\n");
+
+ status = handle_cmdline_files(sys_table, image, cmdline_ptr, "initrd=",
+ efi_get_max_initrd_addr(dram_base,
+ *image_addr),
+ (unsigned long *)&initrd_addr,
+ (unsigned long *)&initrd_size);
+ if (status != EFI_SUCCESS)
+ pr_efi_err(sys_table, "Failed initrd from command line!\n");
+
+ efi_random_get_seed(sys_table);
+
+ /* hibernation expects the runtime regions to stay in the same place */
+ if (!IS_ENABLED(CONFIG_HIBERNATION) && !nokaslr()) {
+ /*
+ * Randomize the base of the UEFI runtime services region.
+ * Preserve the 2 MB alignment of the region by taking a
+ * shift of 21 bit positions into account when scaling
+ * the headroom value using a 32-bit random value.
+ */
+ static const u64 headroom = EFI_RT_VIRTUAL_LIMIT -
+ EFI_RT_VIRTUAL_BASE -
+ EFI_RT_VIRTUAL_SIZE;
+ u32 rnd;
+
+ status = efi_get_random_bytes(sys_table, sizeof(rnd),
+ (u8 *)&rnd);
+ if (status == EFI_SUCCESS) {
+ virtmap_base = EFI_RT_VIRTUAL_BASE +
+ (((headroom >> 21) * rnd) >> (32 - 21));
+ }
+ }
+
+ new_fdt_addr = fdt_addr;
+ status = allocate_new_fdt_and_exit_boot(sys_table, handle,
+ &new_fdt_addr, efi_get_max_fdt_addr(dram_base),
+ initrd_addr, initrd_size, cmdline_ptr,
+ fdt_addr, fdt_size);
+
+ /*
+ * If all went well, we need to return the FDT address to the
+ * calling function so it can be passed to kernel as part of
+ * the kernel boot protocol.
+ */
+ if (status == EFI_SUCCESS)
+ return new_fdt_addr;
+
+ pr_efi_err(sys_table, "Failed to update FDT and exit boot services\n");
+
+ efi_free(sys_table, initrd_size, initrd_addr);
+ efi_free(sys_table, fdt_size, fdt_addr);
+
+fail_free_image:
+ efi_free(sys_table, image_size, *image_addr);
+ efi_free(sys_table, reserve_size, reserve_addr);
+fail_free_cmdline:
+ free_screen_info(sys_table, si);
+ efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);
+fail:
+ return EFI_ERROR;
+}
+
+static int cmp_mem_desc(const void *l, const void *r)
+{
+ const efi_memory_desc_t *left = l, *right = r;
+
+ return (left->phys_addr > right->phys_addr) ? 1 : -1;
+}
+
+/*
+ * Returns whether region @left ends exactly where region @right starts,
+ * or false if either argument is NULL.
+ */
+static bool regions_are_adjacent(efi_memory_desc_t *left,
+ efi_memory_desc_t *right)
+{
+ u64 left_end;
+
+ if (left == NULL || right == NULL)
+ return false;
+
+ left_end = left->phys_addr + left->num_pages * EFI_PAGE_SIZE;
+
+ return left_end == right->phys_addr;
+}
+
+/*
+ * Returns whether region @left and region @right have compatible memory type
+ * mapping attributes, and are both EFI_MEMORY_RUNTIME regions.
+ */
+static bool regions_have_compatible_memory_type_attrs(efi_memory_desc_t *left,
+ efi_memory_desc_t *right)
+{
+ static const u64 mem_type_mask = EFI_MEMORY_WB | EFI_MEMORY_WT |
+ EFI_MEMORY_WC | EFI_MEMORY_UC |
+ EFI_MEMORY_RUNTIME;
+
+ return ((left->attribute ^ right->attribute) & mem_type_mask) == 0;
+}
+
+/*
+ * efi_get_virtmap() - create a virtual mapping for the EFI memory map
+ *
+ * This function populates the virt_addr fields of all memory region descriptors
+ * in @memory_map whose EFI_MEMORY_RUNTIME attribute is set. Those descriptors
+ * are also copied to @runtime_map, and their total count is returned in @count.
+ */
+void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
+ unsigned long desc_size, efi_memory_desc_t *runtime_map,
+ int *count)
+{
+ u64 efi_virt_base = virtmap_base;
+ efi_memory_desc_t *in, *prev = NULL, *out = runtime_map;
+ int l;
+
+ /*
+ * To work around potential issues with the Properties Table feature
+ * introduced in UEFI 2.5, which may split PE/COFF executable images
+ * in memory into several RuntimeServicesCode and RuntimeServicesData
+ * regions, we need to preserve the relative offsets between adjacent
+ * EFI_MEMORY_RUNTIME regions with the same memory type attributes.
+ * The easiest way to find adjacent regions is to sort the memory map
+ * before traversing it.
+ */
+ if (IS_ENABLED(CONFIG_ARM64))
+ sort(memory_map, map_size / desc_size, desc_size, cmp_mem_desc,
+ NULL);
+
+ for (l = 0; l < map_size; l += desc_size, prev = in) {
+ u64 paddr, size;
+
+ in = (void *)memory_map + l;
+ if (!(in->attribute & EFI_MEMORY_RUNTIME))
+ continue;
+
+ paddr = in->phys_addr;
+ size = in->num_pages * EFI_PAGE_SIZE;
+
+ /*
+ * Make the mapping compatible with 64k pages: this allows
+ * a 4k page size kernel to kexec a 64k page size kernel and
+ * vice versa.
+ */
+ if ((IS_ENABLED(CONFIG_ARM64) &&
+ !regions_are_adjacent(prev, in)) ||
+ !regions_have_compatible_memory_type_attrs(prev, in)) {
+
+ paddr = round_down(in->phys_addr, SZ_64K);
+ size += in->phys_addr - paddr;
+
+ /*
+ * Avoid wasting memory on PTEs by choosing a virtual
+ * base that is compatible with section mappings if this
+ * region has the appropriate size and physical
+ * alignment. (Sections are 2 MB on 4k granule kernels)
+ */
+ if (IS_ALIGNED(in->phys_addr, SZ_2M) && size >= SZ_2M)
+ efi_virt_base = round_up(efi_virt_base, SZ_2M);
+ else
+ efi_virt_base = round_up(efi_virt_base, SZ_64K);
+ }
+
+ in->virt_addr = efi_virt_base + in->phys_addr - paddr;
+ efi_virt_base += size;
+
+ memcpy(out, in, desc_size);
+ out = (void *)out + desc_size;
+ ++*count;
+ }
+}