From: Will Deacon <will.deacon@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: marc.zyngier@arm.com, mark.rutland@arm.com, kim.phillips@arm.com,
alex.bennee@linaro.org, christoffer.dall@linaro.org,
tglx@linutronix.de, peterz@infradead.org,
alexander.shishkin@linux.intel.com, robh@kernel.org,
suzuki.poulose@arm.com, pawel.moll@arm.com,
mathieu.poirier@linaro.org, mingo@redhat.com,
linux-kernel@vger.kernel.org, Will Deacon <will.deacon@arm.com>
Subject: [PATCH 04/10] arm64: head.S: Enable EL1 (host) access to SPE when entered at EL2
Date: Fri, 27 Jan 2017 18:07:43 +0000 [thread overview]
Message-ID: <1485540470-11469-5-git-send-email-will.deacon@arm.com> (raw)
In-Reply-To: <1485540470-11469-1-git-send-email-will.deacon@arm.com>
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 | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 4b1abac3485a..7f625d2e8e45 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -592,15 +592,26 @@ 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
ubfx x0, x0, #11, #5 // to EL2 and allow access to
4:
- csel x0, xzr, x0, lt // all PMU counters from EL1
- msr mdcr_el2, x0 // (if they exist)
+ csel x3, xzr, x0, lt // all PMU counters from EL1
+
+ /* Statistical profiling */
+ ubfx x0, x1, #32, #4 // Check ID_AA64DFR0_EL1 PMSVer
+ cbz x0, 6f // Skip if SPE not present
+ cbnz x2, 5f // VHE?
+ mov x1, #(MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT)
+ orr x3, x3, x1 // If we don't have VHE, then
+ b 6f // use EL1&0 translation.
+5: // For VHE, use EL2 translation
+ orr x3, x3, #MDCR_EL2_TPMS // and disable access from EL1
+6:
+ msr mdcr_el2, x3 // Configure debug traps
/* Stage-2 translation */
msr vttbr_el2, xzr
--
2.1.4
next prev parent reply other threads:[~2017-01-27 18:08 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-27 18:07 [PATCH 00/10] Add support for the ARMv8.2 Statistical Profiling Extension Will Deacon
2017-01-27 18:07 ` [PATCH 01/10] arm64: cpufeature: allow for version discrepancy in PMU implementations Will Deacon
2017-01-27 18:07 ` [PATCH 02/10] arm64: cpufeature: Don't enforce system-wide SPE capability Will Deacon
2017-01-27 18:07 ` [PATCH 03/10] arm64: KVM: Save/restore the host SPE state when entering/leaving a VM Will Deacon
2017-02-01 16:29 ` Marc Zyngier
2017-02-02 18:18 ` Will Deacon
2017-02-02 18:21 ` Marc Zyngier
2017-01-27 18:07 ` Will Deacon [this message]
2017-02-01 16:22 ` [PATCH 04/10] arm64: head.S: Enable EL1 (host) access to SPE when entered at EL2 Marc Zyngier
2017-02-09 18:26 ` Mark Rutland
2017-01-27 18:07 ` [PATCH 05/10] genirq: export irq_get_percpu_devid_partition to modules Will Deacon
2017-01-27 18:07 ` [PATCH 06/10] perf/core: Export AUX buffer helpers " Will Deacon
2017-01-27 18:07 ` [PATCH 07/10] perf: Directly pass PERF_AUX_* flags to perf_aux_output_end Will Deacon
2017-02-17 13:40 ` Alexander Shishkin
2017-02-17 14:00 ` Will Deacon
2017-02-17 14:06 ` Alexander Shishkin
2017-02-17 14:42 ` Will Deacon
2017-02-17 14:59 ` Alexander Shishkin
2017-01-27 18:07 ` [PATCH 08/10] perf/core: Add PERF_AUX_FLAG_COLLISION to report colliding samples Will Deacon
2017-03-31 16:44 ` Robin Murphy
2017-01-27 18:07 ` [PATCH 09/10] drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension Will Deacon
2017-01-30 19:03 ` Kim Phillips
2017-01-27 18:07 ` [PATCH 10/10] dt-bindings: Document devicetree binding for ARM SPE Will Deacon
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