On some platform the remote processor's memory map is not statically
configured in TrustZone, so each memory region that is to be accessed by
the remote needs a call into TrustZone to set up the remote's
permissions.
Implement this for the rmtfs memory driver, to give the modem on 8996
access to the shared file system buffers.
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---
drivers/soc/qcom/Kconfig | 1 +
drivers/soc/qcom/rmtfs_mem.c | 34 ++++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index e050eb83341d..a993d19fa562 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -47,6 +47,7 @@ config QCOM_QMI_HELPERS
config QCOM_RMTFS_MEM
tristate "Qualcomm Remote Filesystem memory driver"
depends on ARCH_QCOM
+ select QCOM_SCM
help
The Qualcomm remote filesystem memory driver is used for allocating
and exposing regions of shared memory with remote processors for the
diff --git a/drivers/soc/qcom/rmtfs_mem.c b/drivers/soc/qcom/rmtfs_mem.c
index 0a43b2e8906f..c8999e38b005 100644
--- a/drivers/soc/qcom/rmtfs_mem.c
+++ b/drivers/soc/qcom/rmtfs_mem.c
@@ -37,6 +37,8 @@ struct qcom_rmtfs_mem {
phys_addr_t size;
unsigned int client_id;
+
+ unsigned int perms;
};
static ssize_t qcom_rmtfs_mem_show(struct device *dev,
@@ -151,9 +153,11 @@ static void qcom_rmtfs_mem_release_device(struct device *dev)
static int qcom_rmtfs_mem_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
+ struct qcom_scm_vmperm perms[2];
struct reserved_mem *rmem;
struct qcom_rmtfs_mem *rmtfs_mem;
u32 client_id;
+ u32 vmid;
int ret;
rmem = of_reserved_mem_lookup(node);
@@ -204,10 +208,31 @@ static int qcom_rmtfs_mem_probe(struct platform_device *pdev)
rmtfs_mem->dev.release = qcom_rmtfs_mem_release_device;
+ ret = of_property_read_u32(node, "qcom,vmid", &vmid);
+ if (ret < 0 && ret != -EINVAL) {
+ dev_err(&pdev->dev, "failed to parse qcom,vmid\n");
+ goto remove_cdev;
+ } else if (!ret) {
+ perms[0].vmid = QCOM_SCM_VMID_HLOS;
+ perms[0].perm = QCOM_SCM_PERM_RW;
+ perms[1].vmid = vmid;
+ perms[1].perm = QCOM_SCM_PERM_RW;
+
+ rmtfs_mem->perms = BIT(QCOM_SCM_VMID_HLOS);
+ ret = qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size,
+ &rmtfs_mem->perms, perms, 2);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "assign memory failed\n");
+ goto remove_cdev;
+ }
+ }
+
dev_set_drvdata(&pdev->dev, rmtfs_mem);
return 0;
+remove_cdev:
+ cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);
put_device:
put_device(&rmtfs_mem->dev);
@@ -217,6 +242,15 @@ static int qcom_rmtfs_mem_probe(struct platform_device *pdev)
static int qcom_rmtfs_mem_remove(struct platform_device *pdev)
{
struct qcom_rmtfs_mem *rmtfs_mem = dev_get_drvdata(&pdev->dev);
+ struct qcom_scm_vmperm perm;
+
+ if (rmtfs_mem->perms) {
+ perm.vmid = QCOM_SCM_VMID_HLOS;
+ perm.perm = QCOM_SCM_PERM_RW;
+
+ qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size,
+ &rmtfs_mem->perms, &perm, 1);
+ }
cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);
put_device(&rmtfs_mem->dev);
--
2.15.0
--
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