[v5] Trusted Execution Environment (TEE) driver for Qualcomm TEE (QTEE)

[PATCH v5 08/12] firmware: qcom: tzmem: export shm_bridge create/delete

Posted by Amirreza Zarrabi 6 months, 3 weeks ago

Anyone with access to contiguous physical memory should be able to
share memory with QTEE using shm_bridge.

Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com>
---
 drivers/firmware/qcom/qcom_tzmem.c       | 57 +++++++++++++++++++++++++-------
 include/linux/firmware/qcom/qcom_tzmem.h | 15 +++++++++
 2 files changed, 60 insertions(+), 12 deletions(-)

diff --git a/drivers/firmware/qcom/qcom_tzmem.c b/drivers/firmware/qcom/qcom_tzmem.c
index 4fe333fd2f07..e9e4f06924ae 100644
--- a/drivers/firmware/qcom/qcom_tzmem.c
+++ b/drivers/firmware/qcom/qcom_tzmem.c
@@ -108,25 +108,61 @@ static int qcom_tzmem_init(void)
 	return 0;
 }
 
-static int qcom_tzmem_init_area(struct qcom_tzmem_area *area)
+/**
+ * qcom_tzmem_shm_bridge_create() - Create a SHM bridge.
+ * @paddr: Physical address of the memory to share.
+ * @size: Size of the memory to share.
+ * @handle: Handle to the SHM bridge.
+ *
+ * On platforms that support SHM bridge, this function creates a SHM bridge
+ * for the given memory region with QTEE. The handle returned by this function
+ * must be passed to qcom_tzmem_shm_bridge_delete() to free the SHM bridge.
+ *
+ * Return: On success, returns 0; on failure, returns < 0.
+ */
+int qcom_tzmem_shm_bridge_create(phys_addr_t paddr, size_t size, u64 *handle)
 {
 	u64 pfn_and_ns_perm, ipfn_and_s_perm, size_and_flags;
-	int ret;
 
 	if (!qcom_tzmem_using_shm_bridge)
 		return 0;
 
-	pfn_and_ns_perm = (u64)area->paddr | QCOM_SCM_PERM_RW;
-	ipfn_and_s_perm = (u64)area->paddr | QCOM_SCM_PERM_RW;
-	size_and_flags = area->size | (1 << QCOM_SHM_BRIDGE_NUM_VM_SHIFT);
+	pfn_and_ns_perm = paddr | QCOM_SCM_PERM_RW;
+	ipfn_and_s_perm = paddr | QCOM_SCM_PERM_RW;
+	size_and_flags = size | (1 << QCOM_SHM_BRIDGE_NUM_VM_SHIFT);
+	if (qcom_scm_shm_bridge_create(pfn_and_ns_perm, ipfn_and_s_perm,
+				       size_and_flags, QCOM_SCM_VMID_HLOS,
+				       handle))
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qcom_tzmem_shm_bridge_create);
+
+/**
+ * qcom_tzmem_shm_bridge_delete() - Delete a SHM bridge.
+ * @handle: Handle to the SHM bridge.
+ *
+ * On platforms that support SHM bridge, this function deletes the SHM bridge
+ * for the given memory region. The handle must be the same as the one
+ * returned by qcom_tzmem_shm_bridge_create().
+ */
+void qcom_tzmem_shm_bridge_delete(u64 handle)
+{
+	if (qcom_tzmem_using_shm_bridge)
+		qcom_scm_shm_bridge_delete(handle);
+}
+EXPORT_SYMBOL_GPL(qcom_tzmem_shm_bridge_delete);
+
+static int qcom_tzmem_init_area(struct qcom_tzmem_area *area)
+{
+	int ret;
 
 	u64 *handle __free(kfree) = kzalloc(sizeof(*handle), GFP_KERNEL);
 	if (!handle)
 		return -ENOMEM;
 
-	ret = qcom_scm_shm_bridge_create(pfn_and_ns_perm, ipfn_and_s_perm,
-					 size_and_flags, QCOM_SCM_VMID_HLOS,
-					 handle);
+	ret = qcom_tzmem_shm_bridge_create(area->paddr, area->size, handle);
 	if (ret)
 		return ret;
 
@@ -139,10 +175,7 @@ static void qcom_tzmem_cleanup_area(struct qcom_tzmem_area *area)
 {
 	u64 *handle = area->priv;
 
-	if (!qcom_tzmem_using_shm_bridge)
-		return;
-
-	qcom_scm_shm_bridge_delete(*handle);
+	qcom_tzmem_shm_bridge_delete(*handle);
 	kfree(handle);
 }
 
diff --git a/include/linux/firmware/qcom/qcom_tzmem.h b/include/linux/firmware/qcom/qcom_tzmem.h
index b83b63a0c049..48ac0e5454c7 100644
--- a/include/linux/firmware/qcom/qcom_tzmem.h
+++ b/include/linux/firmware/qcom/qcom_tzmem.h
@@ -53,4 +53,19 @@ DEFINE_FREE(qcom_tzmem, void *, if (_T) qcom_tzmem_free(_T))
 
 phys_addr_t qcom_tzmem_to_phys(void *ptr);
 
+#if IS_ENABLED(CONFIG_QCOM_TZMEM_MODE_SHMBRIDGE)
+int qcom_tzmem_shm_bridge_create(phys_addr_t paddr, size_t size, u64 *handle);
+void qcom_tzmem_shm_bridge_delete(u64 handle);
+#else
+static inline int qcom_tzmem_shm_bridge_create(phys_addr_t paddr,
+					       size_t size, u64 *handle)
+{
+	return 0;
+}
+
+static inline void qcom_tzmem_shm_bridge_delete(u64 handle)
+{
+}
+#endif
+
 #endif /* __QCOM_TZMEM */

-- 
2.34.1

Re: [PATCH v5 08/12] firmware: qcom: tzmem: export shm_bridge create/delete

Posted by Kuldeep Singh 5 months, 2 weeks ago

On 5/27/2025 12:26 PM, Amirreza Zarrabi wrote:
> Anyone with access to contiguous physical memory should be able to
> share memory with QTEE using shm_bridge.
> 
> Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
> Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com>
> ---
>  drivers/firmware/qcom/qcom_tzmem.c       | 57 +++++++++++++++++++++++++-------
>  include/linux/firmware/qcom/qcom_tzmem.h | 15 +++++++++
>  2 files changed, 60 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/firmware/qcom/qcom_tzmem.c b/drivers/firmware/qcom/qcom_tzmem.c
> index 4fe333fd2f07..e9e4f06924ae 100644
> --- a/drivers/firmware/qcom/qcom_tzmem.c
> +++ b/drivers/firmware/qcom/qcom_tzmem.c
> @@ -108,25 +108,61 @@ static int qcom_tzmem_init(void)
>  	return 0;
>  }
>  
> -static int qcom_tzmem_init_area(struct qcom_tzmem_area *area)
> +/**
> + * qcom_tzmem_shm_bridge_create() - Create a SHM bridge.
> + * @paddr: Physical address of the memory to share.
> + * @size: Size of the memory to share.
> + * @handle: Handle to the SHM bridge.
> + *
> + * On platforms that support SHM bridge, this function creates a SHM bridge
> + * for the given memory region with QTEE. The handle returned by this function
> + * must be passed to qcom_tzmem_shm_bridge_delete() to free the SHM bridge.
> + *
> + * Return: On success, returns 0; on failure, returns < 0.
> + */
> +int qcom_tzmem_shm_bridge_create(phys_addr_t paddr, size_t size, u64 *handle)
>  {
>  	u64 pfn_and_ns_perm, ipfn_and_s_perm, size_and_flags;
> -	int ret;
>  
>  	if (!qcom_tzmem_using_shm_bridge)
>  		return 0;
>  
> -	pfn_and_ns_perm = (u64)area->paddr | QCOM_SCM_PERM_RW;
> -	ipfn_and_s_perm = (u64)area->paddr | QCOM_SCM_PERM_RW;
> -	size_and_flags = area->size | (1 << QCOM_SHM_BRIDGE_NUM_VM_SHIFT);
> +	pfn_and_ns_perm = paddr | QCOM_SCM_PERM_RW;
> +	ipfn_and_s_perm = paddr | QCOM_SCM_PERM_RW;
> +	size_and_flags = size | (1 << QCOM_SHM_BRIDGE_NUM_VM_SHIFT);
> +	if (qcom_scm_shm_bridge_create(pfn_and_ns_perm, ipfn_and_s_perm,
> +				       size_and_flags, QCOM_SCM_VMID_HLOS,
> +				       handle))

Can we add a debug log here to ease debugging in future?
Something like this can also work.

pr_err("Shm bridge creation failed, ret: %d, NS PA|Perm: 0x%llx,
size|flags: 0x%llx\n", ret, pfn_and_ns_perm_flags, size_and_flags);

> +		return -EINVAL;
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(qcom_tzmem_shm_bridge_create);

-- 
Regards
Kuldeep

Re: [PATCH v5 08/12] firmware: qcom: tzmem: export shm_bridge create/delete

Posted by Amirreza Zarrabi 5 months, 1 week ago

Hi Kuldeep,

On 7/1/2025 9:47 PM, Kuldeep Singh wrote:
> 
> On 5/27/2025 12:26 PM, Amirreza Zarrabi wrote:
>> Anyone with access to contiguous physical memory should be able to
>> share memory with QTEE using shm_bridge.
>>
>> Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
>> Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com>
>> ---
>>  drivers/firmware/qcom/qcom_tzmem.c       | 57 +++++++++++++++++++++++++-------
>>  include/linux/firmware/qcom/qcom_tzmem.h | 15 +++++++++
>>  2 files changed, 60 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/firmware/qcom/qcom_tzmem.c b/drivers/firmware/qcom/qcom_tzmem.c
>> index 4fe333fd2f07..e9e4f06924ae 100644
>> --- a/drivers/firmware/qcom/qcom_tzmem.c
>> +++ b/drivers/firmware/qcom/qcom_tzmem.c
>> @@ -108,25 +108,61 @@ static int qcom_tzmem_init(void)
>>  	return 0;
>>  }
>>  
>> -static int qcom_tzmem_init_area(struct qcom_tzmem_area *area)
>> +/**
>> + * qcom_tzmem_shm_bridge_create() - Create a SHM bridge.
>> + * @paddr: Physical address of the memory to share.
>> + * @size: Size of the memory to share.
>> + * @handle: Handle to the SHM bridge.
>> + *
>> + * On platforms that support SHM bridge, this function creates a SHM bridge
>> + * for the given memory region with QTEE. The handle returned by this function
>> + * must be passed to qcom_tzmem_shm_bridge_delete() to free the SHM bridge.
>> + *
>> + * Return: On success, returns 0; on failure, returns < 0.
>> + */
>> +int qcom_tzmem_shm_bridge_create(phys_addr_t paddr, size_t size, u64 *handle)
>>  {
>>  	u64 pfn_and_ns_perm, ipfn_and_s_perm, size_and_flags;
>> -	int ret;
>>  
>>  	if (!qcom_tzmem_using_shm_bridge)
>>  		return 0;
>>  
>> -	pfn_and_ns_perm = (u64)area->paddr | QCOM_SCM_PERM_RW;
>> -	ipfn_and_s_perm = (u64)area->paddr | QCOM_SCM_PERM_RW;
>> -	size_and_flags = area->size | (1 << QCOM_SHM_BRIDGE_NUM_VM_SHIFT);
>> +	pfn_and_ns_perm = paddr | QCOM_SCM_PERM_RW;
>> +	ipfn_and_s_perm = paddr | QCOM_SCM_PERM_RW;
>> +	size_and_flags = size | (1 << QCOM_SHM_BRIDGE_NUM_VM_SHIFT);
>> +	if (qcom_scm_shm_bridge_create(pfn_and_ns_perm, ipfn_and_s_perm,
>> +				       size_and_flags, QCOM_SCM_VMID_HLOS,
>> +				       handle))
> 
> Can we add a debug log here to ease debugging in future?
> Something like this can also work.
> 
> pr_err("Shm bridge creation failed, ret: %d, NS PA|Perm: 0x%llx,
> size|flags: 0x%llx\n", ret, pfn_and_ns_perm_flags, size_and_flags);
> 

Sure.

Regards,
Amir

>> +		return -EINVAL;
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(qcom_tzmem_shm_bridge_create);
>