[PATCH] powerpc: Set missing wakeup bit in LPCR on POWER9

[PATCH] powerpc: Set missing wakeup bit in LPCR on POWER9

[Benjamin Herrenschmidt]

There is a new bit, LPCR_PECEu0, which controls wakeup from STOP
states on Hypervisor Virtualization Interrupts (which happen to
also be all external interrupts in host or bare metal mode).

It needs to be set or we will miss wakeups.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

Paul, I haven't fixed KVM. You probably should include such a fix
as part of your KVM-on-power9 series.

Michael: That should probably go to -stable as far as P9 support goes.

 arch/powerpc/include/asm/reg.h        | 2 ++
 arch/powerpc/kernel/cpu_setup_power.S | 8 ++++----
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 9cd4e8c..decef22 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -341,6 +341,8 @@
 #define   LPCR_VRMA_L		ASM_CONST(0x0008000000000000)
 #define   LPCR_VRMA_LP0		ASM_CONST(0x0001000000000000)
 #define   LPCR_VRMA_LP1		ASM_CONST(0x0000800000000000)
+#define   LPCR_PECEu		ASM_CONST(0x0000700000000000)   /* P9 PECE "upper" */
+#define   LPCR_PECEu0		ASM_CONST(0x0000400000000000)   /* P9 Wakeup on HV interrupts" */
 #define   LPCR_RMLS		0x1C000000	/* Implementation dependent RMO limit sel */
 #define   LPCR_RMLS_SH		26
 #define   LPCR_ILE		ASM_CONST(0x0000000002000000)   /* !HV irqs set MSR:LE */
diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S
index 52ff3f0..cbf3375 100644
--- a/arch/powerpc/kernel/cpu_setup_power.S
+++ b/arch/powerpc/kernel/cpu_setup_power.S
@@ -98,8 +98,8 @@ _GLOBAL(__setup_cpu_power9)
 	li	r0,0
 	mtspr	SPRN_LPID,r0
 	mfspr	r3,SPRN_LPCR
-	ori	r3, r3, LPCR_PECEDH
-	ori	r3, r3, LPCR_HVICE
+	LOAD_REG_IMMEDIATE(r4, LPCR_PECEDH | LPCR_PECEu0 | LPCR_HVICE)
+	or	r3, r3, r4
 	bl	__init_LPCR
 	bl	__init_HFSCR
 	bl	__init_tlb_power9
@@ -118,8 +118,8 @@ _GLOBAL(__restore_cpu_power9)
 	li	r0,0
 	mtspr	SPRN_LPID,r0
 	mfspr   r3,SPRN_LPCR
-	ori	r3, r3, LPCR_PECEDH
-	ori	r3, r3, LPCR_HVICE
+	LOAD_REG_IMMEDIATE(r4, LPCR_PECEDH | LPCR_PECEu0 | LPCR_HVICE)
+	or	r3, r3, r4
 	bl	__init_LPCR
 	bl	__init_HFSCR
 	bl	__init_tlb_power9

Re: [PATCH] powerpc: Set missing wakeup bit in LPCR on POWER9

[Michael Ellerman]

Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:

> There is a new bit, LPCR_PECEu0, which controls wakeup from STOP
> states on Hypervisor Virtualization Interrupts (which happen to
> also be all external interrupts in host or bare metal mode).
>
> It needs to be set or we will miss wakeups.
>
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> ---
>
> Paul, I haven't fixed KVM. You probably should include such a fix
> as part of your KVM-on-power9 series.
>
> Michael: That should probably go to -stable as far as P9 support goes.

I ended up with:

    powerpc: Set missing wakeup bit in LPCR on POWER9
    
    There is a new bit, LPCR_PECE_HVEE (Hypervisor Virtualization Exit
    Enable), which controls wakeup from STOP states on Hypervisor
    Virtualization Interrupts (which happen to also be all external
    interrupts in host or bare metal mode).
    
    It needs to be set or we will miss wakeups.
    
    Fixes: 9baaef0a22c8 ("powerpc/irq: Add support for HV virtualization interrupts")
    Cc: stable@vger.kernel.org # v4.8+
    Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    [mpe: Rename it to HVEE to match the name in the ISA]
    Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>


cheers

Re: powerpc: Set missing wakeup bit in LPCR on POWER9

[Michael Ellerman]

On Mon, 2016-11-21 at 07:08:05 UTC, Benjamin Herrenschmidt wrote:
> There is a new bit, LPCR_PECEu0, which controls wakeup from STOP
> states on Hypervisor Virtualization Interrupts (which happen to
> also be all external interrupts in host or bare metal mode).
> 
> It needs to be set or we will miss wakeups.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/7a43906f5cbfb74712af168988455e

cheers