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From: Jiaxun Yang <jiaxun.yang@flygoat.com>
Date: Sat, 11 May 2024 17:00:09 +0100
Subject: [PATCH 2/7] MIPS: csrc-r4k: Apply verification clocksource flags
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Message-Id: <20240511-mips-clks-v1-2-ddb4a10ee9f9@flygoat.com>
References: <20240511-mips-clks-v1-0-ddb4a10ee9f9@flygoat.com>
In-Reply-To: <20240511-mips-clks-v1-0-ddb4a10ee9f9@flygoat.com>
To: Thomas Bogendoerfer <tsbogend@alpha.franken.de>, 
 Serge Semin <fancer.lancer@gmail.com>, 
 Daniel Lezcano <daniel.lezcano@linaro.org>, 
 Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, 
 Jiaxun Yang <jiaxun.yang@flygoat.com>

CP0 counter suffers from various problems like SMP sync,
behaviour on wait.

Set CLOCK_SOURCE_MUST_VERIFY and CLOCK_SOURCE_VERIFY_PERCPU,
as what x86 did to TSC, to let kernel test it before use.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/kernel/csrc-r4k.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/mips/kernel/csrc-r4k.c b/arch/mips/kernel/csrc-r4k.c
index 262896871351..5c37e41e8970 100644
--- a/arch/mips/kernel/csrc-r4k.c
+++ b/arch/mips/kernel/csrc-r4k.c
@@ -21,7 +21,9 @@ static struct clocksource clocksource_mips = {
 	.name		= "MIPS",
 	.read		= c0_hpt_read,
 	.mask		= CLOCKSOURCE_MASK(32),
-	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS |
+				  CLOCK_SOURCE_MUST_VERIFY |
+				  CLOCK_SOURCE_VERIFY_PERCPU,
 };
 
 static u64 __maybe_unused notrace r4k_read_sched_clock(void)

-- 
2.34.1