[PATCH v10 10/15] firmware: qcom: scm: add support for SHM bridge operations

From: Bartosz Golaszewski
Date: Mon May 27 2024 - 08:59:59 EST


From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

SHM Bridge is a safety mechanism allowing to limit the amount of memory
shared between the kernel and the TrustZone to regions explicitly marked
as such.

Add low-level primitives for enabling SHM bridge support as well as
creating and destroying SHM bridges to qcom-scm.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
Acked-by: Andrew Halaney <ahalaney@xxxxxxxxxx>
Tested-by: Andrew Halaney <ahalaney@xxxxxxxxxx> # sc8280xp-lenovo-thinkpad-x13s
Tested-by: Deepti Jaggi <quic_djaggi@xxxxxxxxxxx> #sa8775p-ride
Reviewed-by: Elliot Berman <quic_eberman@xxxxxxxxxxx>
---
drivers/firmware/qcom/qcom_scm.c | 60 ++++++++++++++++++++++++++++++++++
drivers/firmware/qcom/qcom_scm.h | 3 ++
include/linux/firmware/qcom/qcom_scm.h | 6 ++++
3 files changed, 69 insertions(+)

diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index 04131e60b63a..94c34cde8179 100644
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -1344,6 +1344,66 @@ bool qcom_scm_lmh_dcvsh_available(void)
}
EXPORT_SYMBOL_GPL(qcom_scm_lmh_dcvsh_available);

+int qcom_scm_shm_bridge_enable(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_shm_bridge_enable);
+
+int qcom_scm_shm_bridge_create(struct device *dev, u64 pfn_and_ns_perm_flags,
+ u64 ipfn_and_s_perm_flags, u64 size_and_flags,
+ u64 ns_vmids, u64 *handle)
+{
+ struct qcom_scm_desc desc = {
+ .svc = QCOM_SCM_SVC_MP,
+ .cmd = QCOM_SCM_MP_SHM_BRIDGE_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);
+
+ if (handle && !ret)
+ *handle = res.result[1];
+
+ return ret ?: res.result[0];
+}
+EXPORT_SYMBOL_GPL(qcom_scm_shm_bridge_create);
+
+int qcom_scm_shm_bridge_delete(struct device *dev, u64 handle)
+{
+ struct qcom_scm_desc desc = {
+ .svc = QCOM_SCM_SVC_MP,
+ .cmd = QCOM_SCM_MP_SHM_BRIDGE_DELETE,
+ .owner = ARM_SMCCC_OWNER_SIP,
+ .args[0] = handle,
+ .arginfo = QCOM_SCM_ARGS(1, QCOM_SCM_VAL),
+ };
+
+ return qcom_scm_call(__scm->dev, &desc, NULL);
+}
+EXPORT_SYMBOL_GPL(qcom_scm_shm_bridge_delete);
+
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 aa7d06939f8e..cb7273aa0a5e 100644
--- a/drivers/firmware/qcom/qcom_scm.h
+++ b/drivers/firmware/qcom/qcom_scm.h
@@ -116,6 +116,9 @@ struct qcom_tzmem_pool *qcom_scm_get_tzmem_pool(void);
#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_BRIDGE_DELETE 0x1d
+#define QCOM_SCM_MP_SHM_BRIDGE_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 2c51987fb70a..767bffe20766 100644
--- a/include/linux/firmware/qcom/qcom_scm.h
+++ b/include/linux/firmware/qcom/qcom_scm.h
@@ -115,6 +115,12 @@ 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_shm_bridge_enable(void);
+int qcom_scm_shm_bridge_create(struct device *dev, u64 pfn_and_ns_perm_flags,
+ u64 ipfn_and_s_perm_flags, u64 size_and_flags,
+ u64 ns_vmids, u64 *handle);
+int qcom_scm_shm_bridge_delete(struct device *dev, u64 handle);
+
#ifdef CONFIG_QCOM_QSEECOM

int qcom_scm_qseecom_app_get_id(const char *app_name, u32 *app_id);

--
2.43.0