@@ -16,6 +16,7 @@
#include <asm/assembler.h>
#include <asm/cpufeature.h>
#include <asm/alternative.h>
+#include <asm/virt.h>
.text
.pushsection .idmap.text, "ax"
@@ -23,9 +24,14 @@
.align 5
/*
- * cpu_reset(addr) - Helper for cpu_soft_restart.
+ * cpu_reset(addr, el2_switch) - Helper for cpu_soft_restart.
*
* @addr: Location to jump to for soft reset.
+ * @el2_switch: Flag to indicate a swich to EL2 is needed.
+ *
+ * Put the CPU into the same state as it would be if it had been reset, and
+ * branch to what would be the reset vector. It must be executed with the
+ * flat identity mapping.
*/
ENTRY(cpu_reset)
@@ -33,19 +39,28 @@ ENTRY(cpu_reset)
bic x2, x2, #1
msr sctlr_el1, x2 // disable the MMU
isb
- ret x0
+
+ cbz x1, 1f // el2_switch?
+ mov x1, xzr
+ mov x2, xzr
+ mov x3, xzr
+ hvc #HVC_CALL_FUNC // no return
+
+1: ret x0
ENDPROC(cpu_reset)
/*
- * cpu_soft_restart(cpu_reset, addr) - Perform a cpu soft reset.
+ * cpu_soft_restart(cpu_reset, addr, el2_switch) - Perform a cpu soft reset.
*
* @cpu_reset: Physical address of the cpu_reset routine.
* @addr: Location to jump to for soft reset, passed to cpu_reset.
+ * @el2_switch: Flag to indicate a swich to EL2 is needed, passed to cpu_reset.
*/
ENTRY(cpu_soft_restart)
mov x19, x0 // cpu_reset
mov x20, x1 // addr
+ mov x21, x2 // el2_switch
/* Turn D-cache off */
mrs x0, sctlr_el1
@@ -54,6 +69,7 @@ ENTRY(cpu_soft_restart)
isb
mov x0, x20
+ mov x1, x21
ret x19
ENDPROC(cpu_soft_restart)
@@ -11,8 +11,10 @@
#if !defined(_ARM64_CPU_RESET_H)
#define _ARM64_CPU_RESET_H
+#include <asm/virt.h>
+
void __attribute__((noreturn)) cpu_reset(unsigned long addr);
void __attribute__((noreturn)) cpu_soft_restart(phys_addr_t cpu_reset,
- unsigned long addr);
+ unsigned long addr, unsigned long el2_switch);
#endif
When a CPU is reset it needs to be put into the exception level it had when it entered the kernel. Update cpu_reset() to accept an argument which signals if the reset address needs to be entered at EL1 or EL2. Also, update the comments of cpu_reset() and cpu_soft_restart() to reflect this change. Signed-off-by: Geoff Levand <geoff@infradead.org> --- arch/arm64/kernel/cpu-reset.S | 22 +++++++++++++++++++--- arch/arm64/kernel/cpu-reset.h | 4 +++- 2 files changed, 22 insertions(+), 4 deletions(-)