ARM: 8784/1: NOMMU: Allow enter in Hyp mode

ARMv8R adds support for virtualisation extension (with some deviation
from v8A). With this patch hyp-unaware boot code can offload to kernel
setting up HYP stuff in a sane state.
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

arch/arm/kernel/head-nommu.S

@@ -53,7 +53,11 @@ ENTRY(stext)
  THUMB(1:			)
 #endif
 
-	setmode	PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode
+#ifdef CONFIG_ARM_VIRT_EXT
+	bl	__hyp_stub_install
+#endif
+	@ ensure svc mode and all interrupts masked
+	safe_svcmode_maskall r9
 						@ and irqs disabled
 #if defined(CONFIG_CPU_CP15)
 	mrc	p15, 0, r9, c0, c0		@ get processor id
@@ -89,7 +93,11 @@ ENTRY(secondary_startup)
 	 * the processor type - there is no need to check the machine type
 	 * as it has already been validated by the primary processor.
 	 */
-	setmode	PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9
+#ifdef CONFIG_ARM_VIRT_EXT
+	bl	__hyp_stub_install_secondary
+#endif
+	safe_svcmode_maskall r9
+
 #ifndef CONFIG_CPU_CP15
 	ldr	r9, =CONFIG_PROCESSOR_ID
 #else

arch/arm/mm/Kconfig

@@ -702,7 +702,6 @@ config ARM_THUMBEE
 
 config ARM_VIRT_EXT
 	bool
-	depends on MMU
 	default y if CPU_V7
 	help
 	  Enable the kernel to make use of the ARM Virtualization