This is a note to let you know that I've just added the patch titled
powerpc/powernv: Fix CPU hotplug to handle waking on HVI
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-powernv-fix-cpu-hotplug-to-handle-waking-on-hvi.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9b256714979fad61ae11d90b53cf67dd5e6484eb Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Date: Tue, 7 Feb 2017 11:35:31 +1100
Subject: powerpc/powernv: Fix CPU hotplug to handle waking on HVI
From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
commit 9b256714979fad61ae11d90b53cf67dd5e6484eb upstream.
The IPIs come in as HVI not EE, so we need to test the appropriate
SRR1 bits. The encoding is such that it won't have false positives
on P7 and P8 so we can just test it like that. We also need to handle
the icp-opal variant of the flush.
Fixes: d74361881f0d ("powerpc/xics: Add ICP OPAL backend")
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/reg.h | 3 ++-
arch/powerpc/include/asm/xics.h | 1 +
arch/powerpc/platforms/powernv/smp.c | 12 ++++++++++--
arch/powerpc/sysdev/xics/icp-opal.c | 29 +++++++++++++++++++++++++++++
4 files changed, 42 insertions(+), 3 deletions(-)
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -641,9 +641,10 @@
#define SRR1_ISI_N_OR_G 0x10000000 /* ISI: Access is no-exec or G */
#define SRR1_ISI_PROT 0x08000000 /* ISI: Other protection fault */
#define SRR1_WAKEMASK 0x00380000 /* reason for wakeup */
-#define SRR1_WAKEMASK_P8 0x003c0000 /* reason for wakeup on POWER8 */
+#define SRR1_WAKEMASK_P8 0x003c0000 /* reason for wakeup on POWER8 and 9 */
#define SRR1_WAKESYSERR 0x00300000 /* System error */
#define SRR1_WAKEEE 0x00200000 /* External interrupt */
+#define SRR1_WAKEHVI 0x00240000 /* Hypervisor Virtualization Interrupt (P9) */
#define SRR1_WAKEMT 0x00280000 /* mtctrl */
#define SRR1_WAKEHMI 0x00280000 /* Hypervisor maintenance */
#define SRR1_WAKEDEC 0x00180000 /* Decrementer interrupt */
--- a/arch/powerpc/include/asm/xics.h
+++ b/arch/powerpc/include/asm/xics.h
@@ -44,6 +44,7 @@ static inline int icp_hv_init(void) { re
#ifdef CONFIG_PPC_POWERNV
extern int icp_opal_init(void);
+extern void icp_opal_flush_interrupt(void);
#else
static inline int icp_opal_init(void) { return -ENODEV; }
#endif
--- a/arch/powerpc/platforms/powernv/smp.c
+++ b/arch/powerpc/platforms/powernv/smp.c
@@ -155,8 +155,10 @@ static void pnv_smp_cpu_kill_self(void)
wmask = SRR1_WAKEMASK_P8;
idle_states = pnv_get_supported_cpuidle_states();
+
/* We don't want to take decrementer interrupts while we are offline,
- * so clear LPCR:PECE1. We keep PECE2 enabled.
+ * so clear LPCR:PECE1. We keep PECE2 (and LPCR_PECE_HVEE on P9)
+ * enabled as to let IPIs in.
*/
mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1);
@@ -206,8 +208,12 @@ static void pnv_smp_cpu_kill_self(void)
* contains 0.
*/
if (((srr1 & wmask) == SRR1_WAKEEE) ||
+ ((srr1 & wmask) == SRR1_WAKEHVI) ||
(local_paca->irq_happened & PACA_IRQ_EE)) {
- icp_native_flush_interrupt();
+ if (cpu_has_feature(CPU_FTR_ARCH_300))
+ icp_opal_flush_interrupt();
+ else
+ icp_native_flush_interrupt();
} else if ((srr1 & wmask) == SRR1_WAKEHDBELL) {
unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER);
asm volatile(PPC_MSGCLR(%0) : : "r" (msg));
@@ -221,6 +227,8 @@ static void pnv_smp_cpu_kill_self(void)
if (srr1 && !generic_check_cpu_restart(cpu))
DBG("CPU%d Unexpected exit while offline !\n", cpu);
}
+
+ /* Re-enable decrementer interrupts */
mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_PECE1);
DBG("CPU%d coming online...\n", cpu);
}
--- a/arch/powerpc/sysdev/xics/icp-opal.c
+++ b/arch/powerpc/sysdev/xics/icp-opal.c
@@ -132,6 +132,35 @@ static irqreturn_t icp_opal_ipi_action(i
return smp_ipi_demux();
}
+/*
+ * Called when an interrupt is received on an off-line CPU to
+ * clear the interrupt, so that the CPU can go back to nap mode.
+ */
+void icp_opal_flush_interrupt(void)
+{
+ unsigned int xirr;
+ unsigned int vec;
+
+ do {
+ xirr = icp_opal_get_xirr();
+ vec = xirr & 0x00ffffff;
+ if (vec == XICS_IRQ_SPURIOUS)
+ break;
+ if (vec == XICS_IPI) {
+ /* Clear pending IPI */
+ int cpu = smp_processor_id();
+ kvmppc_set_host_ipi(cpu, 0);
+ opal_int_set_mfrr(get_hard_smp_processor_id(cpu), 0xff);
+ } else {
+ pr_err("XICS: hw interrupt 0x%x to offline cpu, "
+ "disabling\n", vec);
+ xics_mask_unknown_vec(vec);
+ }
+
+ /* EOI the interrupt */
+ } while (opal_int_eoi(xirr) > 0);
+}
+
#endif /* CONFIG_SMP */
static const struct icp_ops icp_opal_ops = {
Patches currently in stable-queue which might be from benh@xxxxxxxxxxxxxxxxxxx are
queue-4.9/powerpc-mm-radix-update-erat-flushes-when-invalidating-tlb.patch
queue-4.9/powerpc-powernv-fix-cpu-hotplug-to-handle-waking-on-hvi.patch
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