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Commit 41dd03a9 authored by Tony Breeds's avatar Tony Breeds Committed by Benjamin Herrenschmidt
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powerpc/le: Ensure that the 'stop-self' RTAS token is handled correctly 



Currently we're storing a host endian RTAS token in
rtas_stop_self_args.token.  We then pass that directly to rtas.  This is
fine on big endian however on little endian the token is not what we
expect.

This will typically result in hitting:
	panic("Alas, I survived.\n");

To fix this we always use the stop-self token in host order and always
convert it to be32 before passing this to rtas.

Signed-off-by: default avatarTony Breeds <tony@bakeyournoodle.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 66f9af83

arch/powerpc/platforms/pseries/hotplug-cpu.c

+11 −11
Original line number Diff line number Diff line
@@ -35,12 +35,7 @@ 
#include "offline_states.h"



/* This version can't take the spinlock, because it never returns */

static struct rtas_args rtas_stop_self_args = {

	.token = RTAS_UNKNOWN_SERVICE,

	.nargs = 0,

	.nret = 1,

	.rets = &rtas_stop_self_args.args[0],

};

static int rtas_stop_self_token = RTAS_UNKNOWN_SERVICE;



static DEFINE_PER_CPU(enum cpu_state_vals, preferred_offline_state) =

							CPU_STATE_OFFLINE;
@@ -93,15 +88,20 @@ void set_default_offline_state(int cpu) 


static void rtas_stop_self(void)

{

	struct rtas_args *args = &rtas_stop_self_args;

	struct rtas_args args = {

		.token = cpu_to_be32(rtas_stop_self_token),

		.nargs = 0,

		.nret = 1,

		.rets = &args.args[0],

	};



	local_irq_disable();



	BUG_ON(args->token == RTAS_UNKNOWN_SERVICE);

	BUG_ON(rtas_stop_self_token == RTAS_UNKNOWN_SERVICE);



	printk("cpu %u (hwid %u) Ready to die...\n",

	       smp_processor_id(), hard_smp_processor_id());

	enter_rtas(__pa(args));

	enter_rtas(__pa(&args));



	panic("Alas, I survived.\n");

}
@@ -392,10 +392,10 @@ static int __init pseries_cpu_hotplug_init(void) 
		}

	}



	rtas_stop_self_args.token = rtas_token("stop-self");

	rtas_stop_self_token = rtas_token("stop-self");

	qcss_tok = rtas_token("query-cpu-stopped-state");



	if (rtas_stop_self_args.token == RTAS_UNKNOWN_SERVICE ||

	if (rtas_stop_self_token == RTAS_UNKNOWN_SERVICE ||

			qcss_tok == RTAS_UNKNOWN_SERVICE) {

		printk(KERN_INFO "CPU Hotplug not supported by firmware "

				"- disabling.\n");