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Commit 9728a7c8 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Michael Ellerman
Browse files

powerpc/icp-opal: Fix missing KVM case and harden replay 



The icp-opal call is missing the code from icp-native to recover
interrupts snatched by KVM. Without that, when running KVM, we can
get into a situation where an interrupt is lost and the CPU stuck
with an elevated CPPR.

Also harden replay by always checking the return from opal_int_eoi().

Fixes: d7436188 ("powerpc/xics: Add ICP OPAL backend")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 32b53c01

arch/powerpc/sysdev/xics/icp-opal.c

+24 −7
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <asm/xics.h>

#include <asm/io.h>

#include <asm/opal.h>

#include <asm/kvm_ppc.h>



static void icp_opal_teardown_cpu(void)

{
@@ -39,7 +40,26 @@ static void icp_opal_flush_ipi(void) 
	 * Should we be flagging idle loop instead?

	 * Or creating some task to be scheduled?

	 */

	opal_int_eoi((0x00 << 24) | XICS_IPI);

	if (opal_int_eoi((0x00 << 24) | XICS_IPI) > 0)

		force_external_irq_replay();

}



static unsigned int icp_opal_get_xirr(void)

{

	unsigned int kvm_xirr;

	__be32 hw_xirr;

	int64_t rc;



	/* Handle an interrupt latched by KVM first */

	kvm_xirr = kvmppc_get_xics_latch();

	if (kvm_xirr)

		return kvm_xirr;



	/* Then ask OPAL */

	rc = opal_int_get_xirr(&hw_xirr, false);

	if (rc < 0)

		return 0;

	return be32_to_cpu(hw_xirr);

}



static unsigned int icp_opal_get_irq(void)
@@ -47,12 +67,8 @@ static unsigned int icp_opal_get_irq(void) 
	unsigned int xirr;

	unsigned int vec;

	unsigned int irq;

	int64_t rc;



	rc = opal_int_get_xirr(&xirr, false);

	if (rc < 0)

		return 0;

	xirr = be32_to_cpu(xirr);

	xirr = icp_opal_get_xirr();

	vec = xirr & 0x00ffffff;

	if (vec == XICS_IRQ_SPURIOUS)

		return 0;
@@ -67,7 +83,8 @@ static unsigned int icp_opal_get_irq(void) 
	xics_mask_unknown_vec(vec);



	/* We might learn about it later, so EOI it */

	opal_int_eoi(xirr);

	if (opal_int_eoi(xirr) > 0)

		force_external_irq_replay();



	return 0;

}