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Groups > linux.kernel > #1622031
| From | "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 3/3] powernv:idle: Set LPCR_UPRT on wakeup from deep-stop |
| Date | 2017-04-12 13:50 +0200 |
| Message-ID | <tvoWC-3Wi-9@gated-at.bofh.it> (permalink) |
| References | <tvoWB-3Wi-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> On wakeup from a deep-stop used for CPU-Hotplug, we invoke cur_cpu_spec->cpu_restore() which would set sane default values to various SPRs including LPCR. On POWER9, the cpu_restore_power9() call would would restore LPCR to a sane value that is set at early boot time, thereby clearing LPCR_UPRT. However, LPCR_UPRT is required to be set if we are running in Radix mode. If this is not set we will end up with a crash when we enable IR,DR. To fix this, after returning from cur_cpu_spec->cpu_restore() in the idle exit path, set LPCR_UPRT if we are running in Radix mode. Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> --- arch/powerpc/kernel/idle_book3s.S | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index 6a9bd28..39a9b63 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -804,6 +804,19 @@ no_segments: #endif mtctr r12 bctrl +/* + * cur_cpu_spec->cpu_restore would restore LPCR to a + * sane value that is set at early boot time, + * thereby clearing LPCR_UPRT. + * LPCR_UPRT is required if we are running in Radix mode. + * Set it here if that be the case. + */ +BEGIN_MMU_FTR_SECTION + mfspr r3, SPRN_LPCR + LOAD_REG_IMMEDIATE(r4, LPCR_UPRT) + or r3, r3, r4 + mtspr SPRN_LPCR, r3 +END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX) hypervisor_state_restored: -- 1.9.4
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[PATCH 3/3] powernv:idle: Set LPCR_UPRT on wakeup from deep-stop "Gautham R. Shenoy" <ego@linux.vnet.ibm.com> - 2017-04-12 13:50 +0200
Re: [PATCH 3/3] powernv:idle: Set LPCR_UPRT on wakeup from deep-stop "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> - 2017-04-13 06:10 +0200
Re: [PATCH 3/3] powernv:idle: Set LPCR_UPRT on wakeup from deep-stop Benjamin Herrenschmidt <benh@kernel.crashing.org> - 2017-04-13 06:20 +0200
Re: [PATCH 3/3] powernv:idle: Set LPCR_UPRT on wakeup from deep-stop Michael Neuling <mikey@neuling.org> - 2017-04-13 08:30 +0200
Re: [PATCH 3/3] powernv:idle: Set LPCR_UPRT on wakeup from deep-stop Nicholas Piggin <npiggin@gmail.com> - 2017-04-13 09:20 +0200
Re: [PATCH 3/3] powernv:idle: Set LPCR_UPRT on wakeup from deep-stop Michael Ellerman <mpe@ellerman.id.au> - 2017-04-13 12:10 +0200
Re: [PATCH 3/3] powernv:idle: Set LPCR_UPRT on wakeup from deep-stop Gautham R Shenoy <ego@linux.vnet.ibm.com> - 2017-04-13 14:00 +0200
Re: [PATCH 3/3] powernv:idle: Set LPCR_UPRT on wakeup from deep-stop Nicholas Piggin <npiggin@gmail.com> - 2017-04-13 14:10 +0200
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