diff options
| -rw-r--r-- | arch/arm64/include/asm/assembler.h | 4 | ||||
| -rw-r--r-- | arch/arm64/kernel/setup.c | 11 | ||||
| -rw-r--r-- | arch/arm64/kernel/smp.c | 7 | ||||
| -rw-r--r-- | arch/arm64/mm/proc.S | 10 |
4 files changed, 16 insertions, 16 deletions
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index b27dac4a9c0f..6f9ad2d2bb40 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -50,10 +50,6 @@ msr daif, \flags .endm - .macro enable_dbg - msr daifclr, #8 - .endm - .macro disable_step_tsk, flgs, tmp tbz \flgs, #TIF_SINGLESTEP, 9990f mrs \tmp, mdscr_el1 diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 65a052bf741f..a096e2451044 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -298,8 +298,15 @@ void __init __no_sanitize_address setup_arch(char **cmdline_p) dynamic_scs_init(); /* - * Unmask SError as soon as possible after initializing earlycon so - * that we can report any SErrors immediately. + * The primary CPU enters the kernel with all DAIF exceptions masked. + * + * We must unmask Debug and SError before preemption or scheduling is + * possible to ensure that these are consistently unmasked across + * threads, and we want to unmask SError as soon as possible after + * initializing earlycon so that we can report any SErrors immediately. + * + * IRQ and FIQ will be unmasked after the root irqchip has been + * detected and initialized. */ local_daif_restore(DAIF_PROCCTX_NOIRQ); diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 4ced34f62dab..31c8b3094dd7 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -264,6 +264,13 @@ asmlinkage notrace void secondary_start_kernel(void) set_cpu_online(cpu, true); complete(&cpu_running); + /* + * Secondary CPUs enter the kernel with all DAIF exceptions masked. + * + * As with setup_arch() we must unmask Debug and SError exceptions, and + * as the root irqchip has already been detected and initialized we can + * unmask IRQ and FIQ at the same time. + */ local_daif_restore(DAIF_PROCCTX); /* diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 9d40f3ffd8d2..f4bc6c5bac06 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -135,14 +135,6 @@ SYM_FUNC_START(cpu_do_resume) msr tcr_el1, x8 msr vbar_el1, x9 - - /* - * __cpu_setup() cleared MDSCR_EL1.MDE and friends, before unmasking - * debug exceptions. By restoring MDSCR_EL1 here, we may take a debug - * exception. Mask them until local_daif_restore() in cpu_suspend() - * resets them. - */ - disable_daif msr mdscr_el1, x10 msr sctlr_el1, x12 @@ -466,8 +458,6 @@ SYM_FUNC_START(__cpu_setup) msr cpacr_el1, xzr // Reset cpacr_el1 mov x1, #1 << 12 // Reset mdscr_el1 and disable msr mdscr_el1, x1 // access to the DCC from EL0 - isb // Unmask debug exceptions now, - enable_dbg // since this is per-cpu reset_pmuserenr_el0 x1 // Disable PMU access from EL0 reset_amuserenr_el0 x1 // Disable AMU access from EL0 |