arm64: smp: remove pointless secondary_data maintenance

All reads and writes of secondary_data occur with the MMU on, using
coherent attributes, so there's no need to perform any cache maintenance
for this.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Suzuki Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20210520115031.18509-4-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index dcd7041b2b077f0ece865d5edfb4b1b67e04199c..92e83e8bac948f27524b76b21ec93a4448a89047 100644 (file)
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -122,7 +122,6 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
        secondary_data.task = idle;
        secondary_data.stack = task_stack_page(idle) + THREAD_SIZE;
        update_cpu_boot_status(CPU_MMU_OFF);
-       __flush_dcache_area(&secondary_data, sizeof(secondary_data));
 
        /* Now bring the CPU into our world */
        ret = boot_secondary(cpu, idle);
@@ -143,7 +142,6 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
        pr_crit("CPU%u: failed to come online\n", cpu);
        secondary_data.task = NULL;
        secondary_data.stack = NULL;
-       __flush_dcache_area(&secondary_data, sizeof(secondary_data));
        status = READ_ONCE(secondary_data.status);
        if (status == CPU_MMU_OFF)
                status = READ_ONCE(__early_cpu_boot_status);