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From: Elliot Berman <quic_eberman@quicinc.com>
Date: Tue, 9 Jan 2024 11:37:44 -0800
Subject: [PATCH v16 06/34] virt: gunyah: msgq: Add hypercalls to send and
 receive messages
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Message-ID: <20240109-gunyah-v16-6-634904bf4ce9@quicinc.com>
References: <20240109-gunyah-v16-0-634904bf4ce9@quicinc.com>
In-Reply-To: <20240109-gunyah-v16-0-634904bf4ce9@quicinc.com>
To: Alex Elder <elder@linaro.org>,
        Srinivas Kandagatla
	<srinivas.kandagatla@linaro.org>,
        Murali Nalajal <quic_mnalajal@quicinc.com>,
        Trilok Soni <quic_tsoni@quicinc.com>,
        Srivatsa Vaddagiri
	<quic_svaddagi@quicinc.com>,
        Carl van Schaik <quic_cvanscha@quicinc.com>,
        Philip Derrin <quic_pderrin@quicinc.com>,
        Prakruthi Deepak Heragu
	<quic_pheragu@quicinc.com>,
        Jonathan Corbet <corbet@lwn.net>, Rob Herring
	<robh+dt@kernel.org>,
        Krzysztof Kozlowski
	<krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Bjorn Andersson
	<andersson@kernel.org>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        "Fuad
 Tabba" <tabba@google.com>,
        Sean Christopherson <seanjc@google.com>,
        "Andrew
 Morton" <akpm@linux-foundation.org>
CC: <linux-arm-msm@vger.kernel.org>, <linux-doc@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>, <linux-mm@kvack.org>,
        Elliot Berman
	<quic_eberman@quicinc.com>

Add hypercalls to send and receive messages on a Gunyah message queue.

Reviewed-by: Alex Elder <elder@linaro.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
---
 arch/arm64/gunyah/gunyah_hypercall.c | 55 ++++++++++++++++++++++++++++++++++++
 include/linux/gunyah.h               |  8 ++++++
 2 files changed, 63 insertions(+)

diff --git a/arch/arm64/gunyah/gunyah_hypercall.c b/arch/arm64/gunyah/gunyah_hypercall.c
index d44663334f38..1302e128be6e 100644
--- a/arch/arm64/gunyah/gunyah_hypercall.c
+++ b/arch/arm64/gunyah/gunyah_hypercall.c
@@ -37,6 +37,8 @@ EXPORT_SYMBOL_GPL(arch_is_gunyah_guest);
 
 /* clang-format off */
 #define GUNYAH_HYPERCALL_HYP_IDENTIFY		GUNYAH_HYPERCALL(0x8000)
+#define GUNYAH_HYPERCALL_MSGQ_SEND		GUNYAH_HYPERCALL(0x801B)
+#define GUNYAH_HYPERCALL_MSGQ_RECV		GUNYAH_HYPERCALL(0x801C)
 /* clang-format on */
 
 /**
@@ -58,5 +60,58 @@ void gunyah_hypercall_hyp_identify(
 }
 EXPORT_SYMBOL_GPL(gunyah_hypercall_hyp_identify);
 
+/**
+ * gunyah_hypercall_msgq_send() - Send a buffer on a message queue
+ * @capid: capability ID of the message queue to add message
+ * @size: Size of @buff
+ * @buff: Address of buffer to send
+ * @tx_flags: See GUNYAH_HYPERCALL_MSGQ_TX_FLAGS_*
+ * @ready: If the send was successful, ready is filled with true if more
+ *         messages can be sent on the queue. If false, then the tx IRQ will
+ *         be raised in future when send can succeed.
+ */
+enum gunyah_error gunyah_hypercall_msgq_send(u64 capid, size_t size, void *buff,
+					     u64 tx_flags, bool *ready)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_hvc(GUNYAH_HYPERCALL_MSGQ_SEND, capid, size,
+			  (uintptr_t)buff, tx_flags, 0, &res);
+
+	if (res.a0 == GUNYAH_ERROR_OK)
+		*ready = !!res.a1;
+
+	return res.a0;
+}
+EXPORT_SYMBOL_GPL(gunyah_hypercall_msgq_send);
+
+/**
+ * gunyah_hypercall_msgq_recv() - Send a buffer on a message queue
+ * @capid: capability ID of the message queue to add message
+ * @buff: Address of buffer to copy received data into
+ * @size: Size of @buff
+ * @recv_size: If the receive was successful, recv_size is filled with the
+ *             size of data received. Will be <= size.
+ * @ready: If the receive was successful, ready is filled with true if more
+ *         messages are ready to be received on the queue. If false, then the
+ *         rx IRQ will be raised in future when recv can succeed.
+ */
+enum gunyah_error gunyah_hypercall_msgq_recv(u64 capid, void *buff, size_t size,
+					     size_t *recv_size, bool *ready)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_hvc(GUNYAH_HYPERCALL_MSGQ_RECV, capid, (uintptr_t)buff,
+			  size, 0, &res);
+
+	if (res.a0 == GUNYAH_ERROR_OK) {
+		*recv_size = res.a1;
+		*ready = !!res.a2;
+	}
+
+	return res.a0;
+}
+EXPORT_SYMBOL_GPL(gunyah_hypercall_msgq_recv);
+
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Gunyah Hypervisor Hypercalls");
diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h
index 33bcbd22d39f..acd70f982425 100644
--- a/include/linux/gunyah.h
+++ b/include/linux/gunyah.h
@@ -141,4 +141,12 @@ gunyah_api_version(const struct gunyah_hypercall_hyp_identify_resp *gunyah_api)
 void gunyah_hypercall_hyp_identify(
 	struct gunyah_hypercall_hyp_identify_resp *hyp_identity);
 
+/* Immediately raise RX vIRQ on receiver VM */
+#define GUNYAH_HYPERCALL_MSGQ_TX_FLAGS_PUSH BIT(0)
+
+enum gunyah_error gunyah_hypercall_msgq_send(u64 capid, size_t size, void *buff,
+					     u64 tx_flags, bool *ready);
+enum gunyah_error gunyah_hypercall_msgq_recv(u64 capid, void *buff, size_t size,
+					     size_t *recv_size, bool *ready);
+
 #endif

-- 
2.34.1