From: Jia He <justin.he@arm.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
James Morse <james.morse@arm.com>, Marc Zyngier <maz@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Suzuki Poulose <Suzuki.Poulose@arm.com>
Cc: "Punit Agrawal" <punitagrawal@gmail.com>,
"Anshuman Khandual" <anshuman.khandual@arm.com>,
"Alex Van Brunt" <avanbrunt@nvidia.com>,
"Robin Murphy" <robin.murphy@arm.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Ralph Campbell" <rcampbell@nvidia.com>,
hejianet@gmail.com, "Kaly Xin" <Kaly.Xin@arm.com>,
nd@arm.com, "Jia He" <justin.he@arm.com>
Subject: [PATCH v7 1/3] arm64: cpufeature: introduce helper cpu_has_hw_af()
Date: Fri, 20 Sep 2019 21:54:35 +0800 [thread overview]
Message-ID: <20190920135437.25622-2-justin.he@arm.com> (raw)
In-Reply-To: <20190920135437.25622-1-justin.he@arm.com>
We unconditionally set the HW_AFDBM capability and only enable it on
CPUs which really have the feature. But sometimes we need to know
whether this cpu has the capability of HW AF. So decouple AF from
DBM by new helper cpu_has_hw_af().
Reported-by: kbuild test robot <lkp@intel.com>
Suggested-by: Suzuki Poulose <Suzuki.Poulose@arm.com>
Signed-off-by: Jia He <justin.he@arm.com>
---
arch/arm64/include/asm/cpufeature.h | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index c96ffa4722d3..46caf934ba4e 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -667,6 +667,16 @@ static inline u32 id_aa64mmfr0_parange_to_phys_shift(int parange)
default: return CONFIG_ARM64_PA_BITS;
}
}
+
+/* Decouple AF from AFDBM. */
+static inline bool cpu_has_hw_af(void)
+{
+ if (IS_ENABLED(CONFIG_ARM64_HW_AFDBM))
+ return read_cpuid(ID_AA64MMFR1_EL1) & 0xf;
+
+ return false;
+}
+
#endif /* __ASSEMBLY__ */
#endif
--
2.17.1
next prev parent reply other threads:[~2019-09-20 13:55 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-20 13:54 [PATCH v7 0/3] fix double page fault on arm64 Jia He
2019-09-20 13:54 ` Jia He [this message]
2019-09-20 13:54 ` [PATCH v7 2/3] arm64: mm: implement arch_faults_on_old_pte() " Jia He
2019-09-20 13:54 ` [PATCH v7 3/3] mm: fix double page fault on arm64 if PTE_AF is cleared Jia He
2019-09-20 14:21 ` Kirill A. Shutemov
2019-09-20 14:24 ` Justin He (Arm Technology China)
2019-09-20 15:53 ` Matthew Wilcox
2019-09-20 17:00 ` Kirill A. Shutemov
2019-09-21 13:19 ` Jia He
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