[U-Boot] [PATCH v2 1/1] efi_loader: refactor switch to hypervisor mode

Heinrich Schuchardt xypron.glpk at gmx.de
Wed Dec 26 10:07:37 UTC 2018


Refactor the switch from supervisor to hypervisor to a new function called at
the beginning of do_bootefi().

Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
v2
	Use weak function with implementation in arch directories
---
 arch/arm/cpu/armv7/Makefile          |  1 +
 arch/arm/cpu/armv7/exception_level.c | 41 ++++++++++++++
 arch/arm/cpu/armv8/Makefile          |  1 +
 arch/arm/cpu/armv8/exception_level.c | 40 ++++++++++++++
 cmd/bootefi.c                        | 81 +++++-----------------------
 include/bootm.h                      |  5 ++
 6 files changed, 101 insertions(+), 68 deletions(-)
 create mode 100644 arch/arm/cpu/armv7/exception_level.c
 create mode 100644 arch/arm/cpu/armv8/exception_level.c

diff --git a/arch/arm/cpu/armv7/Makefile b/arch/arm/cpu/armv7/Makefile
index 4f4647c90ac..8c955d0d528 100644
--- a/arch/arm/cpu/armv7/Makefile
+++ b/arch/arm/cpu/armv7/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_SYS_ARM_MPU) += mpu_v7r.o
 
 ifneq ($(CONFIG_SPL_BUILD),y)
 obj-$(CONFIG_EFI_LOADER) += sctlr.o
+obj-$(CONFIG_ARMV7_NONSEC) += exception_level.o
 endif
 
 ifneq ($(CONFIG_SKIP_LOWLEVEL_INIT),y)
diff --git a/arch/arm/cpu/armv7/exception_level.c b/arch/arm/cpu/armv7/exception_level.c
new file mode 100644
index 00000000000..e231fc94633
--- /dev/null
+++ b/arch/arm/cpu/armv7/exception_level.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Switching exception levels
+ *
+ *  Copyright (c) 2018 Heinrich Schuchardt
+ */
+
+#include <common.h>
+#include <bootm.h>
+#include <asm/armv7.h>
+#include <asm/secure.h>
+#include <asm/setjmp.h>
+
+struct jmp_buf_data hyp_jmp;
+
+/**
+ * entry_hyp() - entry point when switching to hypervisor mode
+ */
+static void entry_hyp(void)
+{
+	dcache_enable();
+	debug("Reached HYP mode\n");
+	longjmp(&hyp_jmp, 1);
+}
+
+/**
+ * leave_supervisor() - switch to hypervisor mode
+ */
+void leave_supervisor(void)
+{
+	static bool is_nonsec;
+
+	if (armv7_boot_nonsec() && !is_nonsec) {
+		if (setjmp(&hyp_jmp))
+			return;
+		dcache_disable();	/* flush cache before switch to HYP */
+		armv7_init_nonsec();
+		is_nonsec = true;
+		secure_ram_addr(_do_nonsec_entry)(entry_hyp, 0, 0, 0);
+	}
+}
diff --git a/arch/arm/cpu/armv8/Makefile b/arch/arm/cpu/armv8/Makefile
index 52c8daa0496..8b0b887a696 100644
--- a/arch/arm/cpu/armv8/Makefile
+++ b/arch/arm/cpu/armv8/Makefile
@@ -14,6 +14,7 @@ ifdef CONFIG_SPL_BUILD
 obj-$(CONFIG_ARMV8_SPL_EXCEPTION_VECTORS) += exceptions.o
 else
 obj-y	+= exceptions.o
+obj-y   += exception_level.o
 endif
 obj-y	+= cache.o
 obj-y	+= tlb.o
diff --git a/arch/arm/cpu/armv8/exception_level.c b/arch/arm/cpu/armv8/exception_level.c
new file mode 100644
index 00000000000..ad8211bb85d
--- /dev/null
+++ b/arch/arm/cpu/armv8/exception_level.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  Switching exception levels
+ *
+ *  Copyright (c) 2018 Heinrich Schuchardt
+ */
+
+#include <common.h>
+#include <bootm.h>
+#include <asm/setjmp.h>
+
+static struct jmp_buf_data hyp_jmp;
+
+/**
+ * entry_hyp() - entry point when switching to hypervisor mode
+ */
+static void entry_hyp(void)
+{
+	dcache_enable();
+	debug("Reached HYP mode\n");
+	longjmp(&hyp_jmp, 1);
+}
+
+/**
+ * leave_supervisor() - switch to hypervisor mode
+ */
+void leave_supervisor(void)
+{
+	/* On AArch64 we need to make sure we call our payload in < EL3 */
+	if (current_el() == 3) {
+		if (setjmp(&hyp_jmp))
+			return;
+		smp_kick_all_cpus();
+		dcache_disable();	/* flush cache before switch to EL2 */
+
+		/* Move into EL2 and keep running there */
+		armv8_switch_to_el2(0, 0, 0, 0, (uintptr_t)entry_hyp,
+				    ES_TO_AARCH64);
+	}
+}
diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index 1aaf5319e13..804f527e730 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -5,8 +5,9 @@
  *  Copyright (c) 2016 Alexander Graf
  */
 
-#include <charset.h>
 #include <common.h>
+#include <bootm.h>
+#include <charset.h>
 #include <command.h>
 #include <dm.h>
 #include <efi_dxe.h>
@@ -21,17 +22,11 @@
 #include <asm-generic/unaligned.h>
 #include <linux/linkage.h>
 
-#ifdef CONFIG_ARMV7_NONSEC
-#include <asm/armv7.h>
-#include <asm/secure.h>
-#endif
-
 DECLARE_GLOBAL_DATA_PTR;
 
 #define OBJ_LIST_NOT_INITIALIZED 1
 
 static efi_status_t efi_obj_list_initialized = OBJ_LIST_NOT_INITIALIZED;
-
 static struct efi_device_path *bootefi_image_path;
 static struct efi_device_path *bootefi_device_path;
 
@@ -122,6 +117,15 @@ void __weak allow_unaligned(void)
 {
 }
 
+/**
+ * leave_supervisor() - switch to hypervisor mode
+ *
+ * This routine is overridden by architectures requiring this feature.
+ */
+void __weak leave_supervisor(void)
+{
+}
+
 /*
  * Set the load options of an image from an environment variable.
  *
@@ -233,34 +237,6 @@ static efi_status_t efi_do_enter(
 	return ret;
 }
 
-#ifdef CONFIG_ARM64
-static efi_status_t efi_run_in_el2(EFIAPI efi_status_t (*entry)(
-			efi_handle_t image_handle, struct efi_system_table *st),
-			efi_handle_t image_handle, struct efi_system_table *st)
-{
-	/* Enable caches again */
-	dcache_enable();
-
-	return efi_do_enter(image_handle, st, entry);
-}
-#endif
-
-#ifdef CONFIG_ARMV7_NONSEC
-static bool is_nonsec;
-
-static efi_status_t efi_run_in_hyp(EFIAPI efi_status_t (*entry)(
-			efi_handle_t image_handle, struct efi_system_table *st),
-			efi_handle_t image_handle, struct efi_system_table *st)
-{
-	/* Enable caches again */
-	dcache_enable();
-
-	is_nonsec = true;
-
-	return efi_do_enter(image_handle, st, entry);
-}
-#endif
-
 /*
  * efi_carve_out_dt_rsv() - Carve out DT reserved memory ranges
  *
@@ -440,39 +416,6 @@ static efi_status_t do_bootefi_exec(void *efi,
 		goto err_prepare;
 	}
 
-#ifdef CONFIG_ARM64
-	/* On AArch64 we need to make sure we call our payload in < EL3 */
-	if (current_el() == 3) {
-		smp_kick_all_cpus();
-		dcache_disable();	/* flush cache before switch to EL2 */
-
-		/* Move into EL2 and keep running there */
-		armv8_switch_to_el2((ulong)entry,
-				    (ulong)&image_obj->header,
-				    (ulong)&systab, 0, (ulong)efi_run_in_el2,
-				    ES_TO_AARCH64);
-
-		/* Should never reach here, efi exits with longjmp */
-		while (1) { }
-	}
-#endif
-
-#ifdef CONFIG_ARMV7_NONSEC
-	if (armv7_boot_nonsec() && !is_nonsec) {
-		dcache_disable();	/* flush cache before switch to HYP */
-
-		armv7_init_nonsec();
-		secure_ram_addr(_do_nonsec_entry)(
-					efi_run_in_hyp,
-					(uintptr_t)entry,
-					(uintptr_t)&image_obj->header,
-					(uintptr_t)&systab);
-
-		/* Should never reach here, efi exits with longjmp */
-		while (1) { }
-	}
-#endif
-
 	ret = efi_do_enter(&image_obj->header, &systab, entry);
 
 err_prepare:
@@ -558,6 +501,8 @@ static int do_bootefi(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	/* Allow unaligned memory access */
 	allow_unaligned();
 
+	leave_supervisor();
+
 	/* Initialize EFI drivers */
 	r = efi_init_obj_list();
 	if (r != EFI_SUCCESS) {
diff --git a/include/bootm.h b/include/bootm.h
index 0501414e0dc..c64874c98b5 100644
--- a/include/bootm.h
+++ b/include/bootm.h
@@ -80,4 +80,9 @@ int bootm_decomp_image(int comp, ulong load, ulong image_start, int type,
  */
 void board_quiesce_devices(void);
 
+/**
+ * leave_supervisor() - switch to hypervisor mode
+ */
+void leave_supervisor(void);
+
 #endif
-- 
2.19.2



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