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authorKeerthy <j-keerthy@ti.com>2016-09-14 10:43:32 +0530
committerTom Rini <trini@konsulko.com>2016-10-06 20:58:16 -0400
commitd31d4a2d7523c73b5da03a1697b6438e1fe1b027 (patch)
tree1bfe4392313b45845b4e4abae169f3f611852138 /arch/arm
parent60d42e9d519857921118b91c23a0062935c9d085 (diff)
ARM: Introduce function to switch to hypervisor mode
On some of the SoCs one cannot enable hypervisor mode directly from the u-boot because the ROM code puts the chip to supervisor mode after it jumps to boot loader. Hence introduce a weak function which can be overridden based on the SoC type and switch to hypervisor mode in a custom way. Cc: beagleboard-x15@googlegroups.com Signed-off-by: Keerthy <j-keerthy@ti.com> Reviewed-by: Tom Rini <trini@konsulko.com>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/cpu/armv7/start.S21
-rw-r--r--arch/arm/include/asm/system.h4
2 files changed, 25 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S
index 691e5d3fe1..7eee54ba70 100644
--- a/arch/arm/cpu/armv7/start.S
+++ b/arch/arm/cpu/armv7/start.S
@@ -17,6 +17,7 @@
#include <config.h>
#include <asm/system.h>
#include <linux/linkage.h>
+#include <asm/armv7.h>
/*************************************************************************
*
@@ -30,11 +31,24 @@
.globl reset
.globl save_boot_params_ret
+#ifdef CONFIG_ARMV7_LPAE
+ .global switch_to_hypervisor_ret
+#endif
reset:
/* Allow the board to save important registers */
b save_boot_params
save_boot_params_ret:
+#ifdef CONFIG_ARMV7_LPAE
+/*
+ * check for Hypervisor support
+ */
+ mrc p15, 0, r0, c0, c1, 1 @ read ID_PFR1
+ and r0, r0, #CPUID_ARM_VIRT_MASK @ mask virtualization bits
+ cmp r0, #(1 << CPUID_ARM_VIRT_SHIFT)
+ beq switch_to_hypervisor
+switch_to_hypervisor_ret:
+#endif
/*
* disable interrupts (FIQ and IRQ), also set the cpu to SVC32 mode,
* except if in HYP mode already
@@ -103,6 +117,13 @@ ENTRY(save_boot_params)
ENDPROC(save_boot_params)
.weak save_boot_params
+#ifdef CONFIG_ARMV7_LPAE
+ENTRY(switch_to_hypervisor)
+ b switch_to_hypervisor_ret
+ENDPROC(switch_to_hypervisor)
+ .weak switch_to_hypervisor
+#endif
+
/*************************************************************************
*
* cpu_init_cp15
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 7b7b867521..c18e1e3a10 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -223,6 +223,10 @@ void __noreturn psci_system_reset(bool smc);
*/
void save_boot_params_ret(void);
+#ifdef CONFIG_ARMV7_LPAE
+void switch_to_hypervisor_ret(void);
+#endif
+
#define nop() __asm__ __volatile__("mov\tr0,r0\t@ nop\n\t");
#ifdef __ARM_ARCH_7A__