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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: d74361881f ("powerpc/xics: Add ICP OPAL backend")
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
hifive-unleashed-5.1
Benjamin Herrenschmidt 2017-01-16 11:58:53 -06:00 committed by Michael Ellerman
parent 32b53c012e
commit 9728a7c8ab
1 changed files with 24 additions and 7 deletions
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31
arch/powerpc/sysdev/xics/icp-opal.c
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@ -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;
}