1 files changed, 105 insertions, 247 deletions

diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c
index e97370bdfdb0..9cb814c5ba1b 100644
--- a/drivers/firmware/efi/libstub/efi-stub.c
+++ b/drivers/firmware/efi/libstub/efi-stub.c
@@ -10,14 +10,17 @@
  */
 
 #include <linux/efi.h>
-#include <linux/libfdt.h>
+#include <linux/screen_info.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
+ * 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
@@ -25,42 +28,42 @@
  * 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
-#define EFI_RT_VIRTUAL_SIZE	SZ_512M
 
-#ifdef CONFIG_ARM64
-# define EFI_RT_VIRTUAL_LIMIT	DEFAULT_MAP_WINDOW_64
-#else
-# define EFI_RT_VIRTUAL_LIMIT	TASK_SIZE
+/*
+ * 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;
+static bool flat_va_mapping = (EFI_RT_VIRTUAL_OFFSET != 0);
 
-const efi_system_table_t *efi_system_table;
+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;
+	struct screen_info *si, tmp = {};
 
-	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;
-		}
-	}
+	if (efi_setup_graphics(&tmp, NULL) != EFI_SUCCESS)
+		return NULL;
+
+	si = alloc_screen_info();
+	if (!si)
+		return NULL;
+
+	*si = tmp;
 	return si;
 }
 
@@ -87,266 +90,119 @@ static void install_memreserve_table(void)
 		efi_err("Failed to install memreserve config table!\n");
 }
 
-static unsigned long get_dram_base(void)
+static u32 get_supported_rt_services(void)
 {
-	efi_status_t status;
-	unsigned long map_size, buff_size;
-	unsigned long membase  = EFI_ERROR;
-	struct efi_memory_map map;
-	efi_memory_desc_t *md;
-	struct efi_boot_memmap boot_map;
-
-	boot_map.map		= (efi_memory_desc_t **)&map.map;
-	boot_map.map_size	= &map_size;
-	boot_map.desc_size	= &map.desc_size;
-	boot_map.desc_ver	= NULL;
-	boot_map.key_ptr	= NULL;
-	boot_map.buff_size	= &buff_size;
-
-	status = efi_get_memory_map(&boot_map);
-	if (status != EFI_SUCCESS)
-		return membase;
+	const efi_rt_properties_table_t *rt_prop_table;
+	u32 supported = EFI_RT_SUPPORTED_ALL;
 
-	map.map_end = map.map + map_size;
-
-	for_each_efi_memory_desc_in_map(&map, md) {
-		if (md->attribute & EFI_MEMORY_WB) {
-			if (membase > md->phys_addr)
-				membase = md->phys_addr;
-		}
-	}
+	rt_prop_table = get_efi_config_table(EFI_RT_PROPERTIES_TABLE_GUID);
+	if (rt_prop_table)
+		supported &= rt_prop_table->runtime_services_supported;
 
-	efi_bs_call(free_pool, map.map);
-
-	return membase;
+	return supported;
 }
 
-/*
- * 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(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);
-
-asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint,
-					    unsigned long fdt_addr,
-					    unsigned long fdt_size);
-
-/*
- * 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.
- */
-efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
-				   efi_system_table_t *sys_table_arg)
+efi_status_t efi_handle_cmdline(efi_loaded_image_t *image, char **cmdline_ptr)
 {
-	efi_loaded_image_t *image;
+	char *cmdline __free(efi_pool) = NULL;
 	efi_status_t status;
-	unsigned long image_addr;
-	unsigned long image_size = 0;
-	unsigned long dram_base;
-	/* addr/point and size pairs for memory management*/
-	unsigned long initrd_addr = 0;
-	unsigned long initrd_size = 0;
-	unsigned long fdt_addr = 0;  /* Original DTB */
-	unsigned long fdt_size = 0;
-	char *cmdline_ptr = NULL;
-	int cmdline_size = 0;
-	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;
-	efi_properties_table_t *prop_tbl;
-	unsigned long max_addr;
-
-	efi_system_table = sys_table_arg;
-
-	/* Check if we were booted by the EFI firmware */
-	if (efi_system_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE) {
-		status = EFI_INVALID_PARAMETER;
-		goto fail;
-	}
-
-	status = check_platform_features();
-	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 = efi_system_table->boottime->handle_protocol(handle,
-					&loaded_image_proto, (void *)&image);
-	if (status != EFI_SUCCESS) {
-		efi_err("Failed to get loaded image protocol\n");
-		goto fail;
-	}
-
-	dram_base = get_dram_base();
-	if (dram_base == EFI_ERROR) {
-		efi_err("Failed to find DRAM base\n");
-		status = EFI_LOAD_ERROR;
-		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(image, &cmdline_size);
-	if (!cmdline_ptr) {
+	cmdline = efi_convert_cmdline(image);
+	if (!cmdline) {
 		efi_err("getting command line via LOADED_IMAGE_PROTOCOL\n");
-		status = EFI_OUT_OF_RESOURCES;
-		goto fail;
+		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 (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) {
+		status = efi_parse_options(cmdline);
 		if (status != EFI_SUCCESS) {
-			efi_err("Failed to parse options\n");
-			goto fail_free_cmdline;
+			efi_err("Failed to parse EFI load options\n");
+			return status;
 		}
 	}
 
-	if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && cmdline_size > 0) {
-		status = efi_parse_options(cmdline_ptr);
+	if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) ||
+	    IS_ENABLED(CONFIG_CMDLINE_FORCE) ||
+	    cmdline[0] == 0) {
+		status = efi_parse_options(CONFIG_CMDLINE);
 		if (status != EFI_SUCCESS) {
-			efi_err("Failed to parse options\n");
-			goto fail_free_cmdline;
+			efi_err("Failed to parse built-in command line\n");
+			return status;
 		}
 	}
 
-	efi_info("Booting Linux Kernel...\n");
+	*cmdline_ptr = no_free_ptr(cmdline);
+	return EFI_SUCCESS;
+}
 
-	si = setup_graphics();
+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 = handle_kernel_image(&image_addr, &image_size,
-				     &reserve_addr,
-				     &reserve_size,
-				     dram_base, image);
-	if (status != EFI_SUCCESS) {
-		efi_err("Failed to relocate kernel\n");
-		goto fail_free_screeninfo;
-	}
+	status = check_platform_features();
+	if (status != EFI_SUCCESS)
+		return status;
 
-	efi_retrieve_tpm2_eventlog();
+	si = setup_graphics();
+
+	efi_retrieve_eventlog();
 
 	/* Ask the firmware to clear memory on unclean shutdown */
 	efi_enable_reset_attack_mitigation();
 
-	secure_boot = efi_get_secureboot();
-
-	/*
-	 * 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="))
-			efi_err("Ignoring DTB from command line.\n");
-	} else {
-		status = efi_load_dtb(image, &fdt_addr, &fdt_size);
-
-		if (status != EFI_SUCCESS) {
-			efi_err("Failed to load device tree!\n");
-			goto fail_free_image;
-		}
-	}
-
-	if (fdt_addr) {
-		efi_info("Using DTB from command line\n");
-	} else {
-		/* Look for a device tree configuration table entry. */
-		fdt_addr = (uintptr_t)get_fdt(&fdt_size);
-		if (fdt_addr)
-			efi_info("Using DTB from configuration table\n");
-	}
-
-	if (!fdt_addr)
-		efi_info("Generating empty DTB\n");
-
-	if (!efi_noinitrd) {
-		max_addr = efi_get_max_initrd_addr(dram_base, image_addr);
-		status = efi_load_initrd(image, &initrd_addr, &initrd_size,
-					 ULONG_MAX, max_addr);
-		if (status != EFI_SUCCESS)
-			efi_err("Failed to load initrd!\n");
-	}
+	efi_load_initrd(image, ULONG_MAX, efi_get_max_initrd_addr(image_addr),
+			NULL);
 
 	efi_random_get_seed();
 
-	/*
-	 * If the NX PE data feature is enabled in the properties table, we
-	 * should take care not to create a virtual mapping that changes the
-	 * relative placement of runtime services code and data regions, as
-	 * they may belong to the same PE/COFF executable image in memory.
-	 * The easiest way to achieve that is to simply use a 1:1 mapping.
-	 */
-	prop_tbl = get_efi_config_table(EFI_PROPERTIES_TABLE_GUID);
-	flat_va_mapping = prop_tbl &&
-			  (prop_tbl->memory_protection_attribute &
-			   EFI_PROPERTIES_RUNTIME_MEMORY_PROTECTION_NON_EXECUTABLE_PE_DATA);
-
-	/* hibernation expects the runtime regions to stay in the same place */
-	if (!IS_ENABLED(CONFIG_HIBERNATION) && !efi_nokaslr && !flat_va_mapping) {
-		/*
-		 * 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(sizeof(rnd), (u8 *)&rnd);
-		if (status == EFI_SUCCESS) {
-			virtmap_base = EFI_RT_VIRTUAL_BASE +
-				       (((headroom >> 21) * rnd) >> (32 - 21));
-		}
-	}
+	/* force efi_novamap if SetVirtualAddressMap() is unsupported */
+	efi_novamap |= !(get_supported_rt_services() &
+			 EFI_RT_SUPPORTED_SET_VIRTUAL_ADDRESS_MAP);
 
 	install_memreserve_table();
 
-	status = allocate_new_fdt_and_exit_boot(handle, &fdt_addr,
-						efi_get_max_fdt_addr(dram_base),
-						initrd_addr, initrd_size,
-						cmdline_ptr, fdt_addr, fdt_size);
-	if (status != EFI_SUCCESS)
-		goto fail_free_initrd;
+	status = efi_boot_kernel(handle, image, image_addr, cmdline_ptr);
 
-	efi_enter_kernel(image_addr, fdt_addr, fdt_totalsize((void *)fdt_addr));
-	/* not reached */
+	free_screen_info(si);
+	return status;
+}
 
-fail_free_initrd:
-	efi_err("Failed to update FDT and exit boot services\n");
+/*
+ * 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;
 
-	efi_free(initrd_size, initrd_addr);
-	efi_free(fdt_size, fdt_addr);
+	/*
+	 * 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;
 
-fail_free_image:
-	efi_free(image_size, image_addr);
-	efi_free(reserve_size, reserve_addr);
-fail_free_screeninfo:
-	free_screen_info(si);
-fail_free_cmdline:
-	efi_bs_call(free_pool, cmdline_ptr);
-fail:
-	return status;
+	return efi_bs_call(allocate_pool, EFI_LOADER_DATA, size,
+			   (void **)virtmap);
 }
 
 /*
@@ -364,6 +220,8 @@ void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
 	efi_memory_desc_t *in, *out = runtime_map;
 	int l;
 
+	*count = 0;
+
 	for (l = 0; l < map_size; l += desc_size) {
 		u64 paddr, size;
 
@@ -374,7 +232,7 @@ void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
 		paddr = in->phys_addr;
 		size = in->num_pages * EFI_PAGE_SIZE;
 
-		in->virt_addr = in->phys_addr;
+		in->virt_addr = in->phys_addr + EFI_RT_VIRTUAL_OFFSET;
 		if (efi_novamap) {
 			continue;
 		}