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Groups > linux.kernel > #1550046
| From | Will Deacon <will.deacon@arm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [RFC PATCH 04/10] arm64: head.S: Enable EL1 (host) access to SPE when entered at EL2 |
| Date | 2017-01-03 19:20 +0100 |
| Message-ID | <sVBQJ-1Kc-21@gated-at.bofh.it> (permalink) |
| References | <sVBQJ-1Kc-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
The SPE architecture requires each exception level to enable access to the SPE controls for the exception level below it, since additional context-switch logic may be required to handle the buffer safely. This patch allows EL1 (host) access to the SPE controls when entered at EL2. Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm64/kernel/head.S | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 4b1abac3485a..6a97831dcf3b 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -592,8 +592,8 @@ CPU_LE( movk x0, #0x30d0, lsl #16 ) // Clear EE and E0E on LE systems #endif /* EL2 debug */ - mrs x0, id_aa64dfr0_el1 // Check ID_AA64DFR0_EL1 PMUVer - sbfx x0, x0, #8, #4 + mrs x1, id_aa64dfr0_el1 // Check ID_AA64DFR0_EL1 PMUVer + sbfx x0, x1, #8, #4 cmp x0, #1 b.lt 4f // Skip if no PMU present mrs x0, pmcr_el0 // Disable debug access traps @@ -601,6 +601,16 @@ CPU_LE( movk x0, #0x30d0, lsl #16 ) // Clear EE and E0E on LE systems 4: csel x0, xzr, x0, lt // all PMU counters from EL1 msr mdcr_el2, x0 // (if they exist) + /* Statistical profiling */ + ubfx x0, x1, #32, #4 // Check ID_AA64DFR0_EL1 PMSVer + cbz x0, 5f // Skip if SPE not present + mrs x0, mdcr_el2 // Preserve HPMN field + cmp x2, xzr // If VHE is not enabled, + mov x1, #3 // use EL1&0 translations, + cinc x1, x1, ne // otherwise use EL2 and + bfi x0, x1, #12, #3 // enable/disable access + msr mdcr_el2, x0 // traps accordingly. +5: /* Stage-2 translation */ msr vttbr_el2, xzr -- 2.1.4
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[RFC PATCH 00/10] Add support for the ARMv8.2 Statistical Profiling Extension Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
[RFC PATCH 02/10] arm64: cpufeature: Don't enforce system-wide SPE capability Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
Re: [RFC PATCH 02/10] arm64: cpufeature: Don't enforce system-wide SPE capability Mark Rutland <mark.rutland@arm.com> - 2017-01-04 12:10 +0100
[RFC PATCH 05/10] genirq: export irq_get_percpu_devid_partition to modules Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
[RFC PATCH 01/10] arm64: cpufeature: allow for version discrepancy in PMU implementations Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
Re: [RFC PATCH 01/10] arm64: cpufeature: allow for version discrepancy in PMU implementations Mark Rutland <mark.rutland@arm.com> - 2017-01-04 11:30 +0100
[RFC PATCH 04/10] arm64: head.S: Enable EL1 (host) access to SPE when entered at EL2 Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
[RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Peter Zijlstra <peterz@infradead.org> - 2017-01-04 11:40 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Will Deacon <will.deacon@arm.com> - 2017-01-04 20:20 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Peter Zijlstra <peterz@infradead.org> - 2017-01-05 12:40 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Kim Phillips <kim.phillips@arm.com> - 2017-01-10 23:10 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Will Deacon <will.deacon@arm.com> - 2017-01-11 13:40 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Kim Phillips <kim.phillips@arm.com> - 2017-01-11 22:10 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Will Deacon <will.deacon@arm.com> - 2017-01-13 14:40 +0100
Re: [RFC PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Marc Zyngier <marc.zyngier@arm.com> - 2017-01-12 12:40 +0100
[RFC PATCH 07/10] perf: Directly pass PERF_AUX_* flags to perf_aux_output_end Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
[RFC PATCH 03/10] arm64: KVM: Save/restore the host SPE state when entering/leaving a VM Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
[RFC PATCH 10/10] dt-bindings: Document devicetree binding for ARM SPE Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
[RFC PATCH 08/10] perf/core: Add PERF_AUX_FLAG_COLLISION to report colliding samples Will Deacon <will.deacon@arm.com> - 2017-01-03 19:20 +0100
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