Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Dylan Van Assche <me@dylanvanassche.be>
To:     srinivas.kandagatla@linaro.org, amahesh@qti.qualcomm.com,
        arnd@arndb.de, gregkh@linuxfoundation.org
Cc:     linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
        ~postmarketos/upstreaming@lists.sr.ht, phone-devel@vger.kernel.org,
        Dylan Van Assche <me@dylanvanassche.be>,
        Caleb Connolly <caleb.connolly@linaro.org>
Subject: [PATCH v3 1/2] misc: fastrpc: support complete DMA pool access to the DSP
Date:   Sun,  7 May 2023 10:08:38 +0200
Message-Id: <20230507080839.37578-2-me@dylanvanassche.be>
In-Reply-To: <20230507080839.37578-1-me@dylanvanassche.be>
References: <20230507080839.37578-1-me@dylanvanassche.be>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

To support FastRPC Context Banks which aren't mapped via the SMMU,
make the whole reserved memory region available to the DSP to allow
access to coherent buffers.

This is performed by assigning the memory to the DSP via a hypervisor
call to set the correct permissions for the Virtual Machines on the DSP.
This is only necessary when a memory region is provided for SLPI DSPs
so guard this with a domain ID check.

Signed-off-by: Dylan Van Assche <me@dylanvanassche.be>
Reviewed-by: Caleb Connolly <caleb.connolly@linaro.org>
---
 drivers/misc/fastrpc.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index f48466960f1b..423272bcbbf5 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -2231,6 +2231,8 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 	int i, err, domain_id = -1, vmcount;
 	const char *domain;
 	bool secure_dsp;
+	struct device_node *rmem_node;
+	struct reserved_mem *rmem;
 	unsigned int vmids[FASTRPC_MAX_VMIDS];
 
 	err = of_property_read_string(rdev->of_node, "label", &domain);
@@ -2274,6 +2276,17 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
 		}
 	}
 
+	rmem_node = of_parse_phandle(rdev->of_node, "memory-region", 0);
+	if (domain_id == SDSP_DOMAIN_ID && rmem_node) {
+		rmem = of_reserved_mem_lookup(rmem_node);
+		if (!rmem)
+			return -EINVAL;
+
+		qcom_scm_assign_mem(rmem->base, rmem->size, &data->perms,
+				    data->vmperms, data->vmcount);
+
+	}
+
 	secure_dsp = !(of_property_read_bool(rdev->of_node, "qcom,non-secure-domain"));
 	data->secure = secure_dsp;
 
-- 
2.40.1