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 soft reset address needs to be entered at EL1 or EL2.
This implementation updates cpu_soft_restart() and soft_restart() to pass the return value of is_hyp_mode_available() as the switch argument to cpu_reset(). Also, update the comments of cpu_reset(), cpu_soft_restart() and soft_restart() to reflect this change. Signed-off-by: Geoff Levand <[email protected]> --- arch/arm64/include/asm/proc-fns.h | 4 ++-- arch/arm64/kernel/process.c | 6 ++++- arch/arm64/mm/proc.S | 47 +++++++++++++++++++++++++++++---------- 3 files changed, 42 insertions(+), 15 deletions(-) diff --git a/arch/arm64/include/asm/proc-fns.h b/arch/arm64/include/asm/proc-fns.h index 9a8fd84..339394d 100644 --- a/arch/arm64/include/asm/proc-fns.h +++ b/arch/arm64/include/asm/proc-fns.h @@ -32,8 +32,8 @@ extern void cpu_cache_off(void); extern void cpu_do_idle(void); extern void cpu_do_switch_mm(unsigned long pgd_phys, struct mm_struct *mm); extern void cpu_reset(unsigned long addr) __attribute__((noreturn)); -void cpu_soft_restart(phys_addr_t cpu_reset, - unsigned long addr) __attribute__((noreturn)); +void cpu_soft_restart(phys_addr_t cpu_reset, unsigned long el2_switch, + unsigned long addr) __attribute__((noreturn)); extern void cpu_do_suspend(struct cpu_suspend_ctx *ptr); extern u64 cpu_do_resume(phys_addr_t ptr, u64 idmap_ttbr); diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index c6b1f3b..d894d3e 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -51,6 +51,7 @@ #include <asm/mmu_context.h> #include <asm/processor.h> #include <asm/stacktrace.h> +#include <asm/virt.h> #ifdef CONFIG_CC_STACKPROTECTOR #include <linux/stackprotector.h> @@ -61,7 +62,10 @@ EXPORT_SYMBOL(__stack_chk_guard); void soft_restart(unsigned long addr) { setup_mm_for_reboot(); - cpu_soft_restart(virt_to_phys(cpu_reset), addr); + + cpu_soft_restart(virt_to_phys(cpu_reset), + is_hyp_mode_available(), addr); + /* Should never get here */ BUG(); } diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index fe69f6e..4fe4b7d 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -25,6 +25,7 @@ #include <asm/hwcap.h> #include <asm/pgtable-hwdef.h> #include <asm/pgtable.h> +#include <asm/virt.h> #ifdef CONFIG_ARM64_64K_PAGES #define TCR_TG_FLAGS TCR_TG0_64K | TCR_TG1_64K @@ -57,27 +58,48 @@ ENTRY(cpu_cache_off) ENDPROC(cpu_cache_off) /* - * cpu_reset(loc) + * cpu_reset(el2_switch, loc) - Helper for cpu_soft_restart. * - * Perform a soft reset of the system. 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. + * @cpu_reset: Physical address of the cpu_reset routine. + * @el2_switch: Flag to indicate a swich to EL2 is needed. + * @addr: Location to jump to for soft reset. * - * - loc - location to jump to for soft reset + * 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. */ + .align 5 + ENTRY(cpu_reset) - mrs x1, sctlr_el1 - bic x1, x1, #1 - msr sctlr_el1, x1 // disable the MMU + mrs x2, sctlr_el1 + bic x2, x2, #1 + msr sctlr_el1, x2 // disable the MMU isb - ret x0 + + cbz x0, 1f // el2_switch? + mov x0, x1 + mov x1, xzr + mov x2, xzr + mov x3, xzr + hvc #HVC_CALL_FUNC // no return + +1: ret x1 ENDPROC(cpu_reset) +/* + * cpu_soft_restart(cpu_reset, el2_switch, addr) - Perform a cpu soft reset. + * + * @cpu_reset: Physical address of the cpu_reset routine. + * @el2_switch: Flag to indicate a swich to EL2 is needed, passed to cpu_reset. + * @addr: Location to jump to for soft reset, passed to cpu_reset. + * + */ + ENTRY(cpu_soft_restart) - /* Save address of cpu_reset() and reset address */ - mov x19, x0 - mov x20, x1 + mov x19, x0 // cpu_reset + mov x20, x1 // el2_switch + mov x21, x2 // addr /* Turn D-cache off */ bl cpu_cache_off @@ -86,6 +108,7 @@ ENTRY(cpu_soft_restart) bl flush_cache_all mov x0, x20 + mov x1, x21 ret x19 ENDPROC(cpu_soft_restart) -- 2.1.0 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
