[PATCH v2 04/10] ARM: add file for HYP mode related setup

Fri Mar 23 16:14:16 PDT 2018

This adds routines to add hyp mode vectors and switch back to HYP
mode from SVC. This is needed in both the PBL and Barebox proper.

Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
---
 arch/arm/cpu/Makefile         |   4 ++
 arch/arm/cpu/hyp.S            | 115 ++++++++++++++++++++++++++++++++++++++++++
 arch/arm/cpu/sm_as.S          |  11 ----
 arch/arm/include/asm/secure.h |   8 +++
 4 files changed, 127 insertions(+), 11 deletions(-)
 create mode 100644 arch/arm/cpu/hyp.S

diff --git a/arch/arm/cpu/Makefile b/arch/arm/cpu/Makefile
index 13fe12c31f6f..f86dff975bb4 100644
--- a/arch/arm/cpu/Makefile
+++ b/arch/arm/cpu/Makefile
@@ -9,6 +9,10 @@ obj-$(CONFIG_ARM_EXCEPTIONS) += exceptions.o
 obj-$(CONFIG_MMU) += mmu.o mmu-early.o
 pbl-$(CONFIG_MMU) += mmu-early.o
 lwl-y += lowlevel.o
+obj-y += hyp.o
+AFLAGS_hyp.o :=-Wa,-march=armv7-a -Wa,-mcpu=all
+pbl-y += hyp.o
+AFLAGS_pbl-hyp.o :=-Wa,-march=armv7-a -Wa,-mcpu=all
 endif
 
 obj-$(CONFIG_ARM_EXCEPTIONS) += interrupts.o
diff --git a/arch/arm/cpu/hyp.S b/arch/arm/cpu/hyp.S
new file mode 100644
index 000000000000..435d416f980a
--- /dev/null
+++ b/arch/arm/cpu/hyp.S
@@ -0,0 +1,115 @@
+#include <linux/linkage.h>
+#include <asm/system.h>
+#include <asm/opcodes-virt.h>
+
+.arch_extension sec
+.arch_extension virt
+
+.section ".text_bare_init_","ax"
+
+.data
+	.align  2
+ENTRY(__boot_cpu_mode)
+	.long   0
+.text
+
+ENTRY(__hyp_install)
+	mrs	r12, cpsr
+	and	r12, r12, #MODE_MASK
+
+	@ Save the initial CPU state
+	adr	r0, .L__boot_cpu_mode_offset
+	ldr	r1, [r0]
+	str	r12, [r0, r1]
+
+	cmp	r12, #HYP_MODE
+	movne	pc, lr			@ give up if the CPU is not in HYP mode
+
+	@ Now install the hypervisor stub:
+	adr	r12, __hyp_vectors
+	mcr	p15, 4, r12, c12, c0, 0	@ set hypervisor vector base (HVBAR)
+
+	@ Disable all traps, so we don't get any nasty surprise
+	mov	r12, #0
+	mcr	p15, 4, r12, c1, c1, 0	@ HCR
+	mcr	p15, 4, r12, c1, c1, 2	@ HCPTR
+	mcr	p15, 4, r12, c1, c1, 3	@ HSTR
+
+THUMB(	orr	r12, #(1 << 30)	)	@ HSCTLR.TE
+	mcr	p15, 4, r12, c1, c0, 0	@ HSCTLR
+
+	mrc	p15, 4, r12, c1, c1, 1	@ HDCR
+	and	r12, #0x1f		@ Preserve HPMN
+	mcr	p15, 4, r12, c1, c1, 1	@ HDCR
+
+	@ Make sure NS-SVC is initialised appropriately
+	mrc	p15, 0, r12, c1, c0, 0	@ SCTLR
+	orr	r12, #(1 << 5)		@ CP15 barriers enabled
+	bic	r12, #(3 << 7)		@ Clear SED/ITD for v8 (RES0 for v7)
+	bic	r12, #(3 << 19)		@ WXN and UWXN disabled
+	mcr	p15, 0, r12, c1, c0, 0	@ SCTLR
+
+	mrc	p15, 0, r12, c0, c0, 0	@ MIDR
+	mcr	p15, 4, r12, c0, c0, 0	@ VPIDR
+
+	mrc	p15, 0, r12, c0, c0, 5	@ MPIDR
+	mcr	p15, 4, r12, c0, c0, 5	@ VMPIDR
+	bx	lr
+ENDPROC(__hyp_install)
+
+ENTRY(armv7_hyp_install)
+	mov	r2, lr
+
+	bl	__hyp_install
+
+	/* set the cpu to SVC32 mode, mask irq and fiq */
+	mrs	r12 , cpsr
+	eor	r12, r12, #HYP_MODE
+	tst	r12, #MODE_MASK
+	bic	r12 , r12 , #MODE_MASK
+	orr	r12 , r12 , #(PSR_I_BIT | PSR_F_BIT | SVC_MODE)
+THUMB(	orr	r12 , r12 , #PSR_T_BIT	)
+	bne	1f
+	orr	r12, r12, #PSR_A_BIT
+	adr	lr, 2f
+	msr	spsr_cxsf, r12
+	__MSR_ELR_HYP(14)
+	__ERET
+1:	msr	cpsr_c, r12
+2:
+	mov	pc, r2
+ENDPROC(armv7_hyp_install)
+
+ENTRY(armv7_switch_to_hyp)
+	mov	r0, lr
+	mov	r1, sp		@ save SVC copy of LR and SP
+	isb
+	hvc #0			@ for older asm: .byte 0x70, 0x00, 0x40, 0xe1
+	mov	sp, r1
+	mov	lr, r0		@ restore SVC copy of LR and SP
+
+	bx	lr
+ENDPROC(armv7_switch_to_hyp)
+
+.align 2
+.L__boot_cpu_mode_offset:
+	.long	__boot_cpu_mode - .
+
+/* The HYP trap is crafted to match armv7_switch_to_hyp() */
+__hyp_do_trap:
+	mov lr, r0
+	mov sp, r1
+	bx  lr
+ENDPROC(__hyp_do_trap)
+
+.align 5
+__hyp_vectors:
+__hyp_reset:	W(b)	.
+__hyp_und:	W(b)	.
+__hyp_svc:	W(b)	.
+__hyp_pabort:	W(b)	.
+__hyp_dabort:	W(b)	.
+__hyp_trap:	W(b)	__hyp_do_trap
+__hyp_irq:	W(b)	.
+__hyp_fiq:	W(b)	.
+ENDPROC(__hyp_vectors)
diff --git a/arch/arm/cpu/sm_as.S b/arch/arm/cpu/sm_as.S
index 0d01e1bf2435..de6cd0406f4f 100644
--- a/arch/arm/cpu/sm_as.S
+++ b/arch/arm/cpu/sm_as.S
@@ -148,17 +148,6 @@ hyp_trap:
         mov pc, lr                              @ do no switch modes, but
                                                 @ return to caller
 
-ENTRY(armv7_switch_to_hyp)
-	mov	r0, lr
-	mov	r1, sp		@ save SVC copy of LR and SP
-	isb
-	hvc #0			@ for older asm: .byte 0x70, 0x00, 0x40, 0xe1
-	mov	sp, r1
-	mov	lr, r0		@ restore SVC copy of LR and SP
-
-	bx	lr
-ENDPROC(armv7_switch_to_hyp)
-
 ENTRY(psci_cpu_entry)
 	mrc	p15, 0, r0, c1, c0, 1	@ ACTLR
 	orr	r0, r0, #(1 << 6)	@ Set SMP bit
diff --git a/arch/arm/include/asm/secure.h b/arch/arm/include/asm/secure.h
index a4cb1f6c1c44..4eb2c3ec3011 100644
--- a/arch/arm/include/asm/secure.h
+++ b/arch/arm/include/asm/secure.h
@@ -5,9 +5,17 @@
 
 int armv7_secure_monitor_install(void);
 int __armv7_secure_monitor_install(void);
+
+#ifndef CONFIG_CPU_V8
 void armv7_switch_to_hyp(void);
+void armv7_hyp_install(void);
+#else
+static inline void armv7_switch_to_hyp(void) { };
+static inline void armv7_hyp_install(void) { };
+#endif
 
 extern unsigned char secure_monitor_init_vectors[];
+extern int __boot_cpu_mode;
 
 enum arm_security_state {
 	ARM_STATE_SECURE,
-- 
2.16.1


