[PATCH v10 01/11] firmware: qcom: tzmem: export shm_bridge create/delete
From: Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com>
Date: 2025-09-10 00:11:19
Also in:
dri-devel, linux-arm-msm, linux-hardening, lkml, op-tee
Subsystem:
arm/qualcomm mailing list, arm/qualcomm support, qualcomm trust zone memory allocator, the rest · Maintainers:
Bjorn Andersson, Konrad Dybcio, Bartosz Golaszewski, Linus Torvalds
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> Tested-by: Harshal Dev <redacted> Reviewed-by: Kuldeep Singh <redacted> Signed-off-by: Amirreza Zarrabi <amirreza.zarrabi@oss.qualcomm.com> --- drivers/firmware/qcom/qcom_tzmem.c | 63 ++++++++++++++++++++++++++------ include/linux/firmware/qcom/qcom_tzmem.h | 15 ++++++++ 2 files changed, 67 insertions(+), 11 deletions(-)
diff --git a/drivers/firmware/qcom/qcom_tzmem.c b/drivers/firmware/qcom/qcom_tzmem.c
index 12e448669b8b..9f232e53115e 100644
--- a/drivers/firmware/qcom/qcom_tzmem.c
+++ b/drivers/firmware/qcom/qcom_tzmem.c@@ -110,7 +110,19 @@ 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;
@@ -118,17 +130,49 @@ static int qcom_tzmem_init_area(struct qcom_tzmem_area *area) 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); + + ret = qcom_scm_shm_bridge_create(pfn_and_ns_perm, ipfn_and_s_perm, + size_and_flags, QCOM_SCM_VMID_HLOS, + handle); + if (ret) { + dev_err(qcom_tzmem_dev, + "SHM Bridge failed: ret %d paddr 0x%pa, size %zu\n", + ret, &paddr, size); + + return ret; + } + + 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;
@@ -141,10 +185,7 @@ 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