Commit f34b3e19 authored by Scott Wood's avatar Scott Wood
Browse files

powerpc/e6500: kexec: Handle hardware threads 



The new kernel will be expecting secondary threads to be disabled,
not spinning.

Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
parent 939fbf00

arch/powerpc/kernel/head_64.S

+16 −0
Original line number Diff line number Diff line
@@ -182,6 +182,8 @@ exception_marker: 


#ifdef CONFIG_PPC_BOOK3E

_GLOBAL(fsl_secondary_thread_init)

	mfspr	r4,SPRN_BUCSR



	/* Enable branch prediction */

	lis     r3,BUCSR_INIT@h

	ori     r3,r3,BUCSR_INIT@l
@@ -196,10 +198,24 @@ _GLOBAL(fsl_secondary_thread_init) 
	 * number.  There are two threads per core, so shift everything

	 * but the low bit right by two bits so that the cpu numbering is

	 * continuous.

	 *

	 * If the old value of BUCSR is non-zero, this thread has run

	 * before.  Thus, we assume we are coming from kexec or a similar

	 * scenario, and PIR is already set to the correct value.  This

	 * is a bit of a hack, but there are limited opportunities for

	 * getting information into the thread and the alternatives

	 * seemed like they'd be overkill.  We can't tell just by looking

	 * at the old PIR value which state it's in, since the same value

	 * could be valid for one thread out of reset and for a different

	 * thread in Linux.

	 */



	mfspr	r3, SPRN_PIR

	cmpwi	r4,0

	bne	1f

	rlwimi	r3, r3, 30, 2, 30

	mtspr	SPRN_PIR, r3

1:

#endif



_GLOBAL(generic_secondary_thread_init)

arch/powerpc/platforms/85xx/smp.c

+46 −0
Original line number Diff line number Diff line
@@ -374,9 +374,55 @@ static void mpc85xx_smp_kexec_down(void *arg) 
#else

void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary)

{

	int cpu = smp_processor_id();

	int sibling = cpu_last_thread_sibling(cpu);

	bool notified = false;

	int disable_cpu;

	int disable_threadbit = 0;

	long start = mftb();

	long now;



	local_irq_disable();

	hard_irq_disable();

	mpic_teardown_this_cpu(secondary);



	if (cpu == crashing_cpu && cpu_thread_in_core(cpu) != 0) {

		/*

		 * We enter the crash kernel on whatever cpu crashed,

		 * even if it's a secondary thread.  If that's the case,

		 * disable the corresponding primary thread.

		 */

		disable_threadbit = 1;

		disable_cpu = cpu_first_thread_sibling(cpu);

	} else if (sibling != crashing_cpu &&

		   cpu_thread_in_core(cpu) == 0 &&

		   cpu_thread_in_core(sibling) != 0) {

		disable_threadbit = 2;

		disable_cpu = sibling;

	}



	if (disable_threadbit) {

		while (paca[disable_cpu].kexec_state < KEXEC_STATE_REAL_MODE) {

			barrier();

			now = mftb();

			if (!notified && now - start > 1000000) {

				pr_info("%s/%d: waiting for cpu %d to enter KEXEC_STATE_REAL_MODE (%d)\n",

					__func__, smp_processor_id(),

					disable_cpu,

					paca[disable_cpu].kexec_state);

				notified = true;

			}

		}



		if (notified) {

			pr_info("%s: cpu %d done waiting\n",

				__func__, disable_cpu);

		}



		mtspr(SPRN_TENC, disable_threadbit);

		while (mfspr(SPRN_TENSR) & disable_threadbit)

			cpu_relax();

	}

}

#endif