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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/firmware/efi/libstub/efi-stub.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/firmware/efi/libstub/efi-stub.c')
-rw-r--r--drivers/firmware/efi/libstub/efi-stub.c282
1 files changed, 282 insertions, 0 deletions
diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
new file mode 100644
index 0000000000..f9c1e8a2bd
--- /dev/null
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+ */
+
+#include <linux/efi.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.
+ *
+ * For ARM/ARM64:
+ * 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)
+ *
+ * For RISC-V:
+ * There is no specific reason for which, this address (512MB) can't be used
+ * EFI runtime virtual address for RISC-V. It also helps to use EFI runtime
+ * services on both RV32/RV64. Keep the same runtime virtual address for RISC-V
+ * as well to minimize the code churn.
+ */
+#define EFI_RT_VIRTUAL_BASE SZ_512M
+
+/*
+ * Some architectures map the EFI regions into the kernel's linear map using a
+ * fixed offset.
+ */
+#ifndef EFI_RT_VIRTUAL_OFFSET
+#define EFI_RT_VIRTUAL_OFFSET 0
+#endif
+
+static u64 virtmap_base = EFI_RT_VIRTUAL_BASE;
+static bool flat_va_mapping = (EFI_RT_VIRTUAL_OFFSET != 0);
+
+void __weak free_screen_info(struct screen_info *si)
+{
+}
+
+static struct screen_info *setup_graphics(void)
+{
+ 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_bs_call(locate_handle, EFI_LOCATE_BY_PROTOCOL,
+ &gop_proto, NULL, &size, gop_handle);
+ if (status == EFI_BUFFER_TOO_SMALL) {
+ si = alloc_screen_info();
+ if (!si)
+ return NULL;
+ status = efi_setup_gop(si, &gop_proto, size);
+ if (status != EFI_SUCCESS) {
+ free_screen_info(si);
+ return NULL;
+ }
+ }
+ return si;
+}
+
+static void install_memreserve_table(void)
+{
+ struct linux_efi_memreserve *rsv;
+ efi_guid_t memreserve_table_guid = LINUX_EFI_MEMRESERVE_TABLE_GUID;
+ efi_status_t status;
+
+ status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, sizeof(*rsv),
+ (void **)&rsv);
+ if (status != EFI_SUCCESS) {
+ efi_err("Failed to allocate memreserve entry!\n");
+ return;
+ }
+
+ rsv->next = 0;
+ rsv->size = 0;
+ atomic_set(&rsv->count, 0);
+
+ status = efi_bs_call(install_configuration_table,
+ &memreserve_table_guid, rsv);
+ if (status != EFI_SUCCESS)
+ efi_err("Failed to install memreserve config table!\n");
+}
+
+static u32 get_supported_rt_services(void)
+{
+ const efi_rt_properties_table_t *rt_prop_table;
+ u32 supported = EFI_RT_SUPPORTED_ALL;
+
+ rt_prop_table = get_efi_config_table(EFI_RT_PROPERTIES_TABLE_GUID);
+ if (rt_prop_table)
+ supported &= rt_prop_table->runtime_services_supported;
+
+ return supported;
+}
+
+efi_status_t efi_handle_cmdline(efi_loaded_image_t *image, char **cmdline_ptr)
+{
+ int cmdline_size = 0;
+ efi_status_t status;
+ char *cmdline;
+
+ /*
+ * 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 = efi_convert_cmdline(image, &cmdline_size);
+ if (!cmdline) {
+ efi_err("getting command line via LOADED_IMAGE_PROTOCOL\n");
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
+ IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
+ cmdline_size == 0) {
+ status = efi_parse_options(CONFIG_CMDLINE);
+ if (status != EFI_SUCCESS) {
+ efi_err("Failed to parse options\n");
+ goto fail_free_cmdline;
+ }
+ }
+
+ if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0) {
+ status = efi_parse_options(cmdline);
+ if (status != EFI_SUCCESS) {
+ efi_err("Failed to parse options\n");
+ goto fail_free_cmdline;
+ }
+ }
+
+ *cmdline_ptr = cmdline;
+ return EFI_SUCCESS;
+
+fail_free_cmdline:
+ efi_bs_call(free_pool, cmdline_ptr);
+ return status;
+}
+
+efi_status_t efi_stub_common(efi_handle_t handle,
+ efi_loaded_image_t *image,
+ unsigned long image_addr,
+ char *cmdline_ptr)
+{
+ struct screen_info *si;
+ efi_status_t status;
+
+ status = check_platform_features();
+ if (status != EFI_SUCCESS)
+ return status;
+
+ si = setup_graphics();
+
+ efi_retrieve_tpm2_eventlog();
+
+ /* Ask the firmware to clear memory on unclean shutdown */
+ efi_enable_reset_attack_mitigation();
+
+ efi_load_initrd(image, ULONG_MAX, efi_get_max_initrd_addr(image_addr),
+ NULL);
+
+ efi_random_get_seed();
+
+ /* force efi_novamap if SetVirtualAddressMap() is unsupported */
+ efi_novamap |= !(get_supported_rt_services() &
+ EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP);
+
+ install_memreserve_table();
+
+ status = efi_boot_kernel(handle, image, image_addr, cmdline_ptr);
+
+ free_screen_info(si);
+ return status;
+}
+
+/*
+ * efi_allocate_virtmap() - create a pool allocation for the virtmap
+ *
+ * Create an allocation that is of sufficient size to hold all the memory
+ * descriptors that will be passed to SetVirtualAddressMap() to inform the
+ * firmware about the virtual mapping that will be used under the OS to call
+ * into the firmware.
+ */
+efi_status_t efi_alloc_virtmap(efi_memory_desc_t **virtmap,
+ unsigned long *desc_size, u32 *desc_ver)
+{
+ unsigned long size, mmap_key;
+ efi_status_t status;
+
+ /*
+ * Use the size of the current memory map as an upper bound for the
+ * size of the buffer we need to pass to SetVirtualAddressMap() to
+ * cover all EFI_MEMORY_RUNTIME regions.
+ */
+ size = 0;
+ status = efi_bs_call(get_memory_map, &size, NULL, &mmap_key, desc_size,
+ desc_ver);
+ if (status != EFI_BUFFER_TOO_SMALL)
+ return EFI_LOAD_ERROR;
+
+ return efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
+ (void **)virtmap);
+}
+
+/*
+ * 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, *out = runtime_map;
+ int l;
+
+ *count = 0;
+
+ for (l = 0; l < map_size; l += desc_size) {
+ 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;
+
+ in->virt_addr = in->phys_addr + EFI_RT_VIRTUAL_OFFSET;
+ if (efi_novamap) {
+ continue;
+ }
+
+ /*
+ * 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 (!flat_va_mapping) {
+
+ 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 - paddr;
+ efi_virt_base += size;
+ }
+
+ memcpy(out, in, desc_size);
+ out = (void *)out + desc_size;
+ ++*count;
+ }
+}