Re: [PATCH v2 12/22] arm64: Delay cpu feature checks

From: Suzuki K. Poulose
Date: Tue Oct 13 2015 - 06:12:48 EST


On 08/10/15 12:08, Catalin Marinas wrote:
On Mon, Oct 05, 2015 at 06:02:01PM +0100, Suzuki K. Poulose wrote:
+ /*
+ * second pass allows enable() invoked on active each CPU
+ * to consider interacting capabilities.
+ */

This comment doesn't read properly.


Fixed locally

+ /*XXX: Are we really safe to call printk here ? */
+ pr_crit("FATAL: CPU%d is missing %s : %s \n",
+ smp_processor_id(), cap_type, cap->desc);

I'm not sure it's safe either, basically we haven't fully brought the
CPU into the system.

Btw, we already print "Booted secondary cpu" from secondary_start_kernel()
before we trigger the notifiers. So I think it should be safe to call it
at the moment.


+ asm volatile(
+ " 1: wfe \n\t"
+ " b 1b\n"
+ );
+}

We could add a wfi as well in the mix.

However, if we have PSCI, we should use it to park the CPUs back into
firmware (via cpu_operations.cpu_die), and only use the above loop if
that fails.

Added cpu_die() and falls back to the trap as above.



+/*
+ * Run through the enabled system capabilities and enable() it on this CPU.

s/it/them/


Fixed.

Thanks
Suzuki

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