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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/firmware/efi/libstub/arm64-stub.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/firmware/efi/libstub/arm64-stub.c')
-rw-r--r--drivers/firmware/efi/libstub/arm64-stub.c217
1 files changed, 217 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/arm64-stub.c b/drivers/firmware/efi/libstub/arm64-stub.c
new file mode 100644
index 000000000..e2f90566b
--- /dev/null
+++ b/drivers/firmware/efi/libstub/arm64-stub.c
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org>
+ *
+ * This file implements the EFI boot stub for the arm64 kernel.
+ * Adapted from ARM version by Mark Salter <msalter@redhat.com>
+ */
+
+
+#include <linux/efi.h>
+#include <asm/efi.h>
+#include <asm/memory.h>
+#include <asm/sections.h>
+#include <asm/sysreg.h>
+
+#include "efistub.h"
+
+static bool system_needs_vamap(void)
+{
+ const struct efi_smbios_type4_record *record;
+ const u32 __aligned(1) *socid;
+ const u8 *version;
+
+ /*
+ * Ampere eMAG, Altra, and Altra Max machines crash in SetTime() if
+ * SetVirtualAddressMap() has not been called prior. Most Altra systems
+ * can be identified by the SMCCC soc ID, which is conveniently exposed
+ * via the type 4 SMBIOS records. Otherwise, test the processor version
+ * field. eMAG systems all appear to have the processor version field
+ * set to "eMAG".
+ */
+ record = (struct efi_smbios_type4_record *)efi_get_smbios_record(4);
+ if (!record)
+ return false;
+
+ socid = (u32 *)record->processor_id;
+ switch (*socid & 0xffff000f) {
+ static char const altra[] = "Ampere(TM) Altra(TM) Processor";
+ static char const emag[] = "eMAG";
+
+ default:
+ version = efi_get_smbios_string(&record->header, 4,
+ processor_version);
+ if (!version || (strncmp(version, altra, sizeof(altra) - 1) &&
+ strncmp(version, emag, sizeof(emag) - 1)))
+ break;
+
+ fallthrough;
+
+ case 0x0a160001: // Altra
+ case 0x0a160002: // Altra Max
+ efi_warn("Working around broken SetVirtualAddressMap()\n");
+ return true;
+ }
+
+ return false;
+}
+
+efi_status_t check_platform_features(void)
+{
+ u64 tg;
+
+ /*
+ * If we have 48 bits of VA space for TTBR0 mappings, we can map the
+ * UEFI runtime regions 1:1 and so calling SetVirtualAddressMap() is
+ * unnecessary.
+ */
+ if (VA_BITS_MIN >= 48 && !system_needs_vamap())
+ efi_novamap = true;
+
+ /* UEFI mandates support for 4 KB granularity, no need to check */
+ if (IS_ENABLED(CONFIG_ARM64_4K_PAGES))
+ return EFI_SUCCESS;
+
+ tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_EL1_TGRAN_SHIFT) & 0xf;
+ if (tg < ID_AA64MMFR0_EL1_TGRAN_SUPPORTED_MIN || tg > ID_AA64MMFR0_EL1_TGRAN_SUPPORTED_MAX) {
+ if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
+ efi_err("This 64 KB granular kernel is not supported by your CPU\n");
+ else
+ efi_err("This 16 KB granular kernel is not supported by your CPU\n");
+ return EFI_UNSUPPORTED;
+ }
+ return EFI_SUCCESS;
+}
+
+/*
+ * Distro versions of GRUB may ignore the BSS allocation entirely (i.e., fail
+ * to provide space, and fail to zero it). Check for this condition by double
+ * checking that the first and the last byte of the image are covered by the
+ * same EFI memory map entry.
+ */
+static bool check_image_region(u64 base, u64 size)
+{
+ struct efi_boot_memmap *map;
+ efi_status_t status;
+ bool ret = false;
+ int map_offset;
+
+ status = efi_get_memory_map(&map, false);
+ if (status != EFI_SUCCESS)
+ return false;
+
+ for (map_offset = 0; map_offset < map->map_size; map_offset += map->desc_size) {
+ efi_memory_desc_t *md = (void *)map->map + map_offset;
+ u64 end = md->phys_addr + md->num_pages * EFI_PAGE_SIZE;
+
+ /*
+ * Find the region that covers base, and return whether
+ * it covers base+size bytes.
+ */
+ if (base >= md->phys_addr && base < end) {
+ ret = (base + size) <= end;
+ break;
+ }
+ }
+
+ efi_bs_call(free_pool, map);
+
+ return ret;
+}
+
+efi_status_t handle_kernel_image(unsigned long *image_addr,
+ unsigned long *image_size,
+ unsigned long *reserve_addr,
+ unsigned long *reserve_size,
+ efi_loaded_image_t *image,
+ efi_handle_t image_handle)
+{
+ efi_status_t status;
+ unsigned long kernel_size, kernel_memsize = 0;
+ u32 phys_seed = 0;
+
+ /*
+ * Although relocatable kernels can fix up the misalignment with
+ * respect to MIN_KIMG_ALIGN, the resulting virtual text addresses are
+ * subtly out of sync with those recorded in the vmlinux when kaslr is
+ * disabled but the image required relocation anyway. Therefore retain
+ * 2M alignment if KASLR was explicitly disabled, even if it was not
+ * going to be activated to begin with.
+ */
+ u64 min_kimg_align = efi_nokaslr ? MIN_KIMG_ALIGN : EFI_KIMG_ALIGN;
+
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
+ efi_guid_t li_fixed_proto = LINUX_EFI_LOADED_IMAGE_FIXED_GUID;
+ void *p;
+
+ if (efi_nokaslr) {
+ efi_info("KASLR disabled on kernel command line\n");
+ } else if (efi_bs_call(handle_protocol, image_handle,
+ &li_fixed_proto, &p) == EFI_SUCCESS) {
+ efi_info("Image placement fixed by loader\n");
+ } else {
+ status = efi_get_random_bytes(sizeof(phys_seed),
+ (u8 *)&phys_seed);
+ if (status == EFI_NOT_FOUND) {
+ efi_info("EFI_RNG_PROTOCOL unavailable\n");
+ efi_nokaslr = true;
+ } else if (status != EFI_SUCCESS) {
+ efi_err("efi_get_random_bytes() failed (0x%lx)\n",
+ status);
+ efi_nokaslr = true;
+ }
+ }
+ }
+
+ if (image->image_base != _text)
+ efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n");
+
+ if (!IS_ALIGNED((u64)_text, SEGMENT_ALIGN))
+ efi_err("FIRMWARE BUG: kernel image not aligned on %dk boundary\n",
+ SEGMENT_ALIGN >> 10);
+
+ kernel_size = _edata - _text;
+ kernel_memsize = kernel_size + (_end - _edata);
+ *reserve_size = kernel_memsize;
+
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) {
+ /*
+ * If KASLR is enabled, and we have some randomness available,
+ * locate the kernel at a randomized offset in physical memory.
+ */
+ status = efi_random_alloc(*reserve_size, min_kimg_align,
+ reserve_addr, phys_seed);
+ if (status != EFI_SUCCESS)
+ efi_warn("efi_random_alloc() failed: 0x%lx\n", status);
+ } else {
+ status = EFI_OUT_OF_RESOURCES;
+ }
+
+ if (status != EFI_SUCCESS) {
+ if (!check_image_region((u64)_text, kernel_memsize)) {
+ efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n");
+ } else if (IS_ALIGNED((u64)_text, min_kimg_align)) {
+ /*
+ * Just execute from wherever we were loaded by the
+ * UEFI PE/COFF loader if the alignment is suitable.
+ */
+ *image_addr = (u64)_text;
+ *reserve_size = 0;
+ return EFI_SUCCESS;
+ }
+
+ status = efi_allocate_pages_aligned(*reserve_size, reserve_addr,
+ ULONG_MAX, min_kimg_align);
+
+ if (status != EFI_SUCCESS) {
+ efi_err("Failed to relocate kernel\n");
+ *reserve_size = 0;
+ return status;
+ }
+ }
+
+ *image_addr = *reserve_addr;
+ memcpy((void *)*image_addr, _text, kernel_size);
+
+ return EFI_SUCCESS;
+}