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From:   Bartosz Golaszewski <brgl@bgdev.pl>
To:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Maximilian Luz <luzmaximilian@gmail.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc:     linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        kernel@quicinc.com,
        Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Subject: [PATCH v2 10/11] firmware: qcom-scm: add support for SHM bridge operations
Date:   Thu, 28 Sep 2023 11:20:39 +0200
Message-Id: <20230928092040.9420-11-brgl@bgdev.pl>
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References: <20230928092040.9420-1-brgl@bgdev.pl>
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From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Add low-level primitives for enabling SHM bridge support, creating SHM
bridge pools and testing the availability of SHM bridges to qcom-scm. We
don't yet provide a way to destroy the bridges as the first user will
not require it.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/firmware/qcom/qcom_scm.c       | 43 ++++++++++++++++++++++++++
 drivers/firmware/qcom/qcom_scm.h       |  2 ++
 include/linux/firmware/qcom/qcom_scm.h |  6 ++++
 3 files changed, 51 insertions(+)

diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index 1fa27c44f472..5969ff0c0beb 100644
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -1296,6 +1296,49 @@ bool qcom_scm_lmh_dcvsh_available(void)
 }
 EXPORT_SYMBOL_GPL(qcom_scm_lmh_dcvsh_available);
 
+int qcom_scm_enable_shm_bridge(void)
+{
+	struct qcom_scm_desc desc = {
+		.svc = QCOM_SCM_SVC_MP,
+		.cmd = QCOM_SCM_MP_SHM_BRIDGE_ENABLE,
+		.owner = ARM_SMCCC_OWNER_SIP
+	};
+
+	struct qcom_scm_res res;
+
+	if (!__qcom_scm_is_call_available(__scm->dev, QCOM_SCM_SVC_MP,
+					  QCOM_SCM_MP_SHM_BRIDGE_ENABLE))
+		return -EOPNOTSUPP;
+
+	return qcom_scm_call(__scm->dev, &desc, &res) ?: res.result[0];
+}
+EXPORT_SYMBOL_GPL(qcom_scm_enable_shm_bridge);
+
+int qcom_scm_create_shm_bridge(struct device *dev, u64 pfn_and_ns_perm_flags,
+			       u64 ipfn_and_s_perm_flags, u64 size_and_flags,
+			       u64 ns_vmids)
+{
+	struct qcom_scm_desc desc = {
+		.svc = QCOM_SCM_SVC_MP,
+		.cmd = QCOM_SCM_MP_SHM_BRDIGE_CREATE,
+		.owner = ARM_SMCCC_OWNER_SIP,
+		.args[0] = pfn_and_ns_perm_flags,
+		.args[1] = ipfn_and_s_perm_flags,
+		.args[2] = size_and_flags,
+		.args[3] = ns_vmids,
+		.arginfo = QCOM_SCM_ARGS(4, QCOM_SCM_VAL, QCOM_SCM_VAL,
+					 QCOM_SCM_VAL, QCOM_SCM_VAL),
+	};
+
+	struct qcom_scm_res res;
+	int ret;
+
+	ret = qcom_scm_call(__scm->dev, &desc, &res);
+
+	return ret ?: res.result[0];
+}
+EXPORT_SYMBOL_GPL(qcom_scm_create_shm_bridge);
+
 int qcom_scm_lmh_profile_change(u32 profile_id)
 {
 	struct qcom_scm_desc desc = {
diff --git a/drivers/firmware/qcom/qcom_scm.h b/drivers/firmware/qcom/qcom_scm.h
index 8c97e3906afa..f5a29bc0f549 100644
--- a/drivers/firmware/qcom/qcom_scm.h
+++ b/drivers/firmware/qcom/qcom_scm.h
@@ -116,6 +116,8 @@ extern int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc,
 #define QCOM_SCM_MP_IOMMU_SET_CP_POOL_SIZE	0x05
 #define QCOM_SCM_MP_VIDEO_VAR			0x08
 #define QCOM_SCM_MP_ASSIGN			0x16
+#define QCOM_SCM_MP_SHM_BRIDGE_ENABLE		0x1c
+#define QCOM_SCM_MP_SHM_BRDIGE_CREATE		0x1e
 
 #define QCOM_SCM_SVC_OCMEM		0x0f
 #define QCOM_SCM_OCMEM_LOCK_CMD		0x01
diff --git a/include/linux/firmware/qcom/qcom_scm.h b/include/linux/firmware/qcom/qcom_scm.h
index 291ef8fd21b0..dc26cfd6d011 100644
--- a/include/linux/firmware/qcom/qcom_scm.h
+++ b/include/linux/firmware/qcom/qcom_scm.h
@@ -6,6 +6,7 @@
 #define __QCOM_SCM_H
 
 #include <linux/cleanup.h>
+#include <linux/device.h>
 #include <linux/err.h>
 #include <linux/gfp.h>
 #include <linux/types.h>
@@ -122,6 +123,11 @@ int qcom_scm_lmh_dcvsh(u32 payload_fn, u32 payload_reg, u32 payload_val,
 int qcom_scm_lmh_profile_change(u32 profile_id);
 bool qcom_scm_lmh_dcvsh_available(void);
 
+int qcom_scm_enable_shm_bridge(void);
+int qcom_scm_create_shm_bridge(struct device *dev, u64 pfn_and_ns_perm_flags,
+			       u64 ipfn_and_s_perm_flags, u64 size_and_flags,
+			       u64 ns_vmids);
+
 #ifdef CONFIG_QCOM_QSEECOM
 
 int qcom_scm_qseecom_app_get_id(const char *app_name, u32 *app_id);
-- 
2.39.2