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 --- arch/arm/cpu/armv7/start.S | 21 +++++++++++++++++++++ arch/arm/include/asm/system.h | 4 ++++ 2 files changed, 25 insertions(+)
diff --git a/arch/arm/cpu/armv7/start.S b/arch/arm/cpu/armv7/start.S index 691e5d3..7eee54b 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 7b7b867..c18e1e3 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__