Re: [PATCH v3 10/15] firmware: qcom: scm: make qcom_scm_qseecom_app_get_id() use the TZ allocator

From: Maximilian Luz
Date: Wed Oct 11 2023 - 16:09:19 EST


On 10/9/23 17:34, Bartosz Golaszewski wrote:
From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

Let's use the new TZ memory allocator to obtain a buffer for this call
instead of manually kmalloc()ing it and then mapping to physical space.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

Tested-by: Maximilian Luz <luzmaximilian@xxxxxxxxx>

I've tested the whole series with both QCOM_TZMEM_MODE_DEFAULT and
QCOM_TZMEM_MODE_SHMBRIDGE. Everything seems to work fine on my Surface
Pro X (sc8180x), but I've only really tested the qseecom-related parts
(hence my TB only for those).

I'll try to do a proper review of the two qseecom patches in the next
couple of days.

---
drivers/firmware/qcom/qcom_scm.c | 18 ++++--------------
1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index 11638daa2fe5..3a6cefb4eb2e 100644
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -1525,37 +1525,27 @@ int qcom_scm_qseecom_app_get_id(const char *app_name, u32 *app_id)
unsigned long app_name_len = strlen(app_name);
struct qcom_scm_desc desc = {};
struct qcom_scm_qseecom_resp res = {};
- dma_addr_t name_buf_phys;
- char *name_buf;
int status;
if (app_name_len >= name_buf_size)
return -EINVAL;
- name_buf = kzalloc(name_buf_size, GFP_KERNEL);
+ char *name_buf __free(qcom_tzmem) = qcom_tzmem_alloc(__scm->mempool,
+ name_buf_size,
+ GFP_KERNEL);
if (!name_buf)
return -ENOMEM;
memcpy(name_buf, app_name, app_name_len);
- name_buf_phys = dma_map_single(__scm->dev, name_buf, name_buf_size, DMA_TO_DEVICE);
- status = dma_mapping_error(__scm->dev, name_buf_phys);
- if (status) {
- kfree(name_buf);
- dev_err(__scm->dev, "qseecom: failed to map dma address\n");
- return status;
- }
-
desc.owner = QSEECOM_TZ_OWNER_QSEE_OS;
desc.svc = QSEECOM_TZ_SVC_APP_MGR;
desc.cmd = QSEECOM_TZ_CMD_APP_LOOKUP;
desc.arginfo = QCOM_SCM_ARGS(2, QCOM_SCM_RW, QCOM_SCM_VAL);
- desc.args[0] = name_buf_phys;
+ desc.args[0] = qcom_tzmem_to_phys(name_buf);
desc.args[1] = app_name_len;
status = qcom_scm_qseecom_call(&desc, &res);
- dma_unmap_single(__scm->dev, name_buf_phys, name_buf_size, DMA_TO_DEVICE);
- kfree(name_buf);
if (status)
return status;