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From: Leo Yan <leo.yan@linaro.org>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Kees Cook <keescook@chromium.org>,
	Ard Biesheuvel <ardb@kernel.org>,
	Sami Tolvanen <samitolvanen@google.com>,
	Nicholas Piggin <npiggin@gmail.com>,
	James Morse <james.morse@arm.com>, Marc Zyngier <maz@kernel.org>,
	Joey Gouly <joey.gouly@arm.com>,
	Peter Collingbourne <pcc@google.com>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>,
	Stephane Eranian <eranian@google.com>,
	James Clark <james.clark@arm.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Cc: Leo Yan <leo.yan@linaro.org>
Subject: [RFCv1 3/4] arm64: Introduce functions for controlling PID tracing
Date: Thu, 21 Oct 2021 21:45:29 +0800	[thread overview]
Message-ID: <20211021134530.206216-4-leo.yan@linaro.org> (raw)
In-Reply-To: <20211021134530.206216-1-leo.yan@linaro.org>

Introduce two functions contextidr_enable() and contextidr_disable(),
which can be used by kernel modules to turn on or off PID tracing in
contextidr register.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 arch/arm64/include/asm/mmu_context.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
index e1f33616f83a..0c1669db19a1 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -37,6 +37,16 @@ static inline void contextidr_thread_switch(struct task_struct *next)
 	isb();
 }
 
+static inline void contextidr_enable(void)
+{
+	static_branch_inc(&contextidr_in_use);
+}
+
+static inline void contextidr_disable(void)
+{
+	static_branch_dec(&contextidr_in_use);
+}
+
 /*
  * Set TTBR0 to reserved_pg_dir. No translations will be possible via TTBR0.
  */
-- 
2.25.1


  parent reply	other threads:[~2021-10-21 13:46 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-21 13:45 [RFCv1 0/4] arm64: Use static key for PID in CONTEXTIDR Leo Yan
2021-10-21 13:45 ` [RFCv1 1/4] arm64: Use static key for tracing " Leo Yan
2021-10-21 14:33   ` James Clark
2021-10-21 14:37     ` Leo Yan
2021-10-21 15:47     ` Kees Cook
2021-10-21 13:45 ` [RFCv1 2/4] arm64: entry: Always apply workaround for contextidr_el1 Leo Yan
2021-10-21 13:45 ` Leo Yan [this message]
2021-10-21 13:45 ` [RFCv1 4/4] perf: arm_spe: Dynamically switch PID tracing to contextidr Leo Yan
2021-10-21 15:49   ` Kees Cook
2021-10-22  2:09     ` Leo Yan
2021-11-01 15:28     ` Leo Yan
2021-12-03 16:22       ` Catalin Marinas
2021-12-05 13:51         ` Leo Yan
2021-12-07 11:48           ` Catalin Marinas
2021-12-07 12:31             ` Leo Yan
2021-12-08 17:29               ` Catalin Marinas
2021-12-10  7:59                 ` Leo Yan
2021-12-17  7:58                   ` Leo Yan
2022-01-17 18:48                   ` Catalin Marinas
2022-02-01 13:02                     ` Leo Yan
2021-10-22 15:36   ` James Clark
2021-10-22 15:40     ` James Clark
2021-10-22 16:23     ` James Clark
2021-10-24 10:25       ` Leo Yan

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