This is a note to let you know that I've just added the patch titled
powerpc/powernv: Enable HAIL (HV AIL) for ISA v3.1 processors
to the 5.12-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-enable-hail-hv-ail-for-isa-v3.1-processors.patch
and it can be found in the queue-5.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 49c1d07fd04f54eb588c4a1dfcedc8d22c5ffd50 Mon Sep 17 00:00:00 2001
From: Nicholas Piggin <npiggin@xxxxxxxxx>
Date: Fri, 2 Apr 2021 12:41:24 +1000
Subject: powerpc/powernv: Enable HAIL (HV AIL) for ISA v3.1 processors
From: Nicholas Piggin <npiggin@xxxxxxxxx>
commit 49c1d07fd04f54eb588c4a1dfcedc8d22c5ffd50 upstream.
Starting with ISA v3.1, LPCR[AIL] no longer controls the interrupt
mode for HV=1 interrupts. Instead, a new LPCR[HAIL] bit is defined
which behaves like AIL=3 for HV interrupts when set.
Set HAIL on bare metal to give us mmu-on interrupts and improve
performance.
This also fixes an scv bug: we don't implement scv real mode (AIL=0)
vectors because they are at an inconvenient location, so we just
disable scv support when AIL can not be set. However powernv assumes
that LPCR[AIL] will enable AIL mode so it enables scv support despite
HV interrupts being AIL=0, which causes scv interrupts to go off into
the weeds.
Fixes: 7fa95f9adaee ("powerpc/64s: system call support for scv/rfscv instructions")
Cc: stable@xxxxxxxxxxxxxxx # v5.9+
Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210402024124.545826-1-npiggin@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/reg.h | 1 +
arch/powerpc/kernel/setup_64.c | 19 ++++++++++++++++---
2 files changed, 17 insertions(+), 3 deletions(-)
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -441,6 +441,7 @@
#define LPCR_VRMA_LP1 ASM_CONST(0x0000800000000000)
#define LPCR_RMLS 0x1C000000 /* Implementation dependent RMO limit sel */
#define LPCR_RMLS_SH 26
+#define LPCR_HAIL ASM_CONST(0x0000000004000000) /* HV AIL (ISAv3.1) */
#define LPCR_ILE ASM_CONST(0x0000000002000000) /* !HV irqs set MSR:LE */
#define LPCR_AIL ASM_CONST(0x0000000001800000) /* Alternate interrupt location */
#define LPCR_AIL_0 ASM_CONST(0x0000000000000000) /* MMU off exception offset 0x0 */
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -232,10 +232,23 @@ static void cpu_ready_for_interrupts(voi
* If we are not in hypervisor mode the job is done once for
* the whole partition in configure_exceptions().
*/
- if (cpu_has_feature(CPU_FTR_HVMODE) &&
- cpu_has_feature(CPU_FTR_ARCH_207S)) {
+ if (cpu_has_feature(CPU_FTR_HVMODE)) {
unsigned long lpcr = mfspr(SPRN_LPCR);
- mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3);
+ unsigned long new_lpcr = lpcr;
+
+ if (cpu_has_feature(CPU_FTR_ARCH_31)) {
+ /* P10 DD1 does not have HAIL */
+ if (pvr_version_is(PVR_POWER10) &&
+ (mfspr(SPRN_PVR) & 0xf00) == 0x100)
+ new_lpcr |= LPCR_AIL_3;
+ else
+ new_lpcr |= LPCR_HAIL;
+ } else if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+ new_lpcr |= LPCR_AIL_3;
+ }
+
+ if (new_lpcr != lpcr)
+ mtspr(SPRN_LPCR, new_lpcr);
}
/*
Patches currently in stable-queue which might be from npiggin@xxxxxxxxx are
queue-5.12/powerpc-powernv-enable-hail-hv-ail-for-isa-v3.1-processors.patch
