From: Steven Price <steven.price@arm.com>
To: Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
Catalin Marinas <catalin.marinas@arm.com>,
linux-doc@vger.kernel.org, Russell King <linux@armlinux.org.uk>,
Steven Price <steven.price@arm.com>,
Paolo Bonzini <pbonzini@redhat.com>
Subject: [PATCH v7 08/10] arm/arm64: Provide a wrapper for SMCCC 1.1 calls
Date: Mon, 21 Oct 2019 16:28:21 +0100 [thread overview]
Message-ID: <20191021152823.14882-9-steven.price@arm.com> (raw)
In-Reply-To: <20191021152823.14882-1-steven.price@arm.com>
SMCCC 1.1 calls may use either HVC or SMC depending on the PSCI
conduit. Rather than coding this in every call site, provide a macro
which uses the correct instruction. The macro also handles the case
where no conduit is configured/available returning a not supported error
in res, along with returning the conduit used for the call.
This allow us to remove some duplicated code and will be useful later
when adding paravirtualized time hypervisor calls.
Signed-off-by: Steven Price <steven.price@arm.com>
Acked-by: Will Deacon <will@kernel.org>
---
include/linux/arm-smccc.h | 45 +++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index 92e0046ce7a7..59494df0f55b 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -319,6 +319,51 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
#define SMCCC_RET_NOT_SUPPORTED -1
#define SMCCC_RET_NOT_REQUIRED -2
+/*
+ * Like arm_smccc_1_1* but always returns SMCCC_RET_NOT_SUPPORTED.
+ * Used when the SMCCC conduit is not defined. The empty asm statement
+ * avoids compiler warnings about unused variables.
+ */
+#define __fail_smccc_1_1(...) \
+ do { \
+ __declare_args(__count_args(__VA_ARGS__), __VA_ARGS__); \
+ asm ("" __constraints(__count_args(__VA_ARGS__))); \
+ if (___res) \
+ ___res->a0 = SMCCC_RET_NOT_SUPPORTED; \
+ } while (0)
+
+/*
+ * arm_smccc_1_1_invoke() - make an SMCCC v1.1 compliant call
+ *
+ * This is a variadic macro taking one to eight source arguments, and
+ * an optional return structure.
+ *
+ * @a0-a7: arguments passed in registers 0 to 7
+ * @res: result values from registers 0 to 3
+ *
+ * This macro will make either an HVC call or an SMC call depending on the
+ * current SMCCC conduit. If no valid conduit is available then -1
+ * (SMCCC_RET_NOT_SUPPORTED) is returned in @res.a0 (if supplied).
+ *
+ * The return value also provides the conduit that was used.
+ */
+#define arm_smccc_1_1_invoke(...) ({ \
+ int method = arm_smccc_1_1_get_conduit(); \
+ switch (method) { \
+ case SMCCC_CONDUIT_HVC: \
+ arm_smccc_1_1_hvc(__VA_ARGS__); \
+ break; \
+ case SMCCC_CONDUIT_SMC: \
+ arm_smccc_1_1_smc(__VA_ARGS__); \
+ break; \
+ default: \
+ __fail_smccc_1_1(__VA_ARGS__); \
+ method = SMCCC_CONDUIT_NONE; \
+ break; \
+ } \
+ method; \
+ })
+
/* Paravirtualised time calls (defined by ARM DEN0057A) */
#define ARM_SMCCC_HV_PV_TIME_FEATURES \
ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
--
2.20.1
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next prev parent reply other threads:[~2019-10-21 15:29 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-21 15:28 [PATCH v7 00/10] arm64: Stolen time support Steven Price
2019-10-21 15:28 ` [PATCH v7 01/10] KVM: arm64: Document PV-time interface Steven Price
2019-10-21 15:28 ` [PATCH v7 02/10] KVM: arm/arm64: Factor out hypercall handling from PSCI code Steven Price
2019-10-21 15:28 ` [PATCH v7 03/10] KVM: arm64: Implement PV_TIME_FEATURES call Steven Price
2019-10-21 15:28 ` [PATCH v7 04/10] KVM: Implement kvm_put_guest() Steven Price
2019-10-21 15:28 ` [PATCH v7 05/10] KVM: arm64: Support stolen time reporting via shared structure Steven Price
2019-10-21 15:28 ` [PATCH v7 06/10] KVM: Allow kvm_device_ops to be const Steven Price
2019-10-21 15:28 ` [PATCH v7 07/10] KVM: arm64: Provide VCPU attributes for stolen time Steven Price
2019-10-21 15:28 ` Steven Price [this message]
2019-10-21 15:28 ` [PATCH v7 09/10] arm/arm64: Make use of the SMCCC 1.1 wrapper Steven Price
2019-10-25 15:50 ` Catalin Marinas
2019-10-21 15:28 ` [PATCH v7 10/10] arm64: Retrieve stolen time as paravirtualized guest Steven Price
2019-10-25 15:57 ` Catalin Marinas
2019-10-21 18:37 ` [PATCH v7 00/10] arm64: Stolen time support Marc Zyngier
2019-10-23 12:39 ` Marc Zyngier
2019-10-23 13:50 ` Steven Price
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