Merge tag 'qcom-drivers-fixes-for-6.9' of https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux into for-next

Qualcomm driver fix for v6.9

This reworks the memory layout of the argument buffers passed to trusted
applications in QSEECOM, to avoid failures and system crashes.

* tag 'qcom-drivers-fixes-for-6.9' of https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux:
  firmware: qcom: uefisecapp: Fix memory related IO errors and crashes

Link: https://lore.kernel.org/r/20240420163816.1133528-1-andersson@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

2 files changed, 97 insertions, 77 deletions

diff --git a/drivers/firmware/qcom/qcom_qseecom_uefisecapp.c b/drivers/firmware/qcom/qcom_qseecom_uefisecapp.c
index 32188f098ef3..bc550ad0dbe0 100644
--- a/drivers/firmware/qcom/qcom_qseecom_uefisecapp.c
+++ b/drivers/firmware/qcom/qcom_qseecom_uefisecapp.c
@@ -221,6 +221,19 @@ struct qsee_rsp_uefi_query_variable_info {
  * alignment of 8 bytes (64 bits) for GUIDs. Our definition of efi_guid_t,
  * however, has an alignment of 4 byte (32 bits). So far, this seems to work
  * fine here. See also the comment on the typedef of efi_guid_t.
+ *
+ * Note: It looks like uefisecapp is quite picky about how the memory passed to
+ * it is structured and aligned. In particular the request/response setup used
+ * for QSEE_CMD_UEFI_GET_VARIABLE. While qcom_qseecom_app_send(), in theory,
+ * accepts separate buffers/addresses for the request and response parts, in
+ * practice, however, it seems to expect them to be both part of a larger
+ * contiguous block. We initially allocated separate buffers for the request
+ * and response but this caused the QSEE_CMD_UEFI_GET_VARIABLE command to
+ * either not write any response to the response buffer or outright crash the
+ * device. Therefore, we now allocate a single contiguous block of DMA memory
+ * for both and properly align the data using the macros below. In particular,
+ * request and response structs are aligned at 8 byte (via __reqdata_offs()),
+ * following the driver that this has been reverse-engineered from.
  */
 #define qcuefi_buf_align_fields(fields...)					\
 	({									\
@@ -244,6 +257,12 @@ struct qsee_rsp_uefi_query_variable_info {
 #define __array_offs(type, count, offset)					\
 	__field_impl(sizeof(type) * (count), __alignof__(type), offset)
 
+#define __array_offs_aligned(type, count, align, offset)			\
+	__field_impl(sizeof(type) * (count), align, offset)
+
+#define __reqdata_offs(size, offset)						\
+	__array_offs_aligned(u8, size, 8, offset)
+
 #define __array(type, count)		__array_offs(type, count, NULL)
 #define __field_offs(type, offset)	__array_offs(type, 1, offset)
 #define __field(type)			__array_offs(type, 1, NULL)
@@ -277,10 +296,15 @@ static efi_status_t qsee_uefi_get_variable(struct qcuefi_client *qcuefi, const e
 	unsigned long buffer_size = *data_size;
 	efi_status_t efi_status = EFI_SUCCESS;
 	unsigned long name_length;
+	dma_addr_t cmd_buf_dma;
+	size_t cmd_buf_size;
+	void *cmd_buf;
 	size_t guid_offs;
 	size_t name_offs;
 	size_t req_size;
 	size_t rsp_size;
+	size_t req_offs;
+	size_t rsp_offs;
 	ssize_t status;
 
 	if (!name || !guid)
@@ -304,17 +328,19 @@ static efi_status_t qsee_uefi_get_variable(struct qcuefi_client *qcuefi, const e
 		__array(u8, buffer_size)
 	);
 
-	req_data = kzalloc(req_size, GFP_KERNEL);
-	if (!req_data) {
+	cmd_buf_size = qcuefi_buf_align_fields(
+		__reqdata_offs(req_size, &req_offs)
+		__reqdata_offs(rsp_size, &rsp_offs)
+	);
+
+	cmd_buf = qseecom_dma_alloc(qcuefi->client, cmd_buf_size, &cmd_buf_dma, GFP_KERNEL);
+	if (!cmd_buf) {
 		efi_status = EFI_OUT_OF_RESOURCES;
 		goto out;
 	}
 
-	rsp_data = kzalloc(rsp_size, GFP_KERNEL);
-	if (!rsp_data) {
-		efi_status = EFI_OUT_OF_RESOURCES;
-		goto out_free_req;
-	}
+	req_data = cmd_buf + req_offs;
+	rsp_data = cmd_buf + rsp_offs;
 
 	req_data->command_id = QSEE_CMD_UEFI_GET_VARIABLE;
 	req_data->data_size = buffer_size;
@@ -332,7 +358,9 @@ static efi_status_t qsee_uefi_get_variable(struct qcuefi_client *qcuefi, const e
 
 	memcpy(((void *)req_data) + req_data->guid_offset, guid, req_data->guid_size);
 
-	status = qcom_qseecom_app_send(qcuefi->client, req_data, req_size, rsp_data, rsp_size);
+	status = qcom_qseecom_app_send(qcuefi->client,
+				       cmd_buf_dma + req_offs, req_size,
+				       cmd_buf_dma + rsp_offs, rsp_size);
 	if (status) {
 		efi_status = EFI_DEVICE_ERROR;
 		goto out_free;
@@ -407,9 +435,7 @@ static efi_status_t qsee_uefi_get_variable(struct qcuefi_client *qcuefi, const e
 	memcpy(data, ((void *)rsp_data) + rsp_data->data_offset, rsp_data->data_size);
 
 out_free:
-	kfree(rsp_data);
-out_free_req:
-	kfree(req_data);
+	qseecom_dma_free(qcuefi->client, cmd_buf_size, cmd_buf, cmd_buf_dma);
 out:
 	return efi_status;
 }
@@ -422,10 +448,15 @@ static efi_status_t qsee_uefi_set_variable(struct qcuefi_client *qcuefi, const e
 	struct qsee_rsp_uefi_set_variable *rsp_data;
 	efi_status_t efi_status = EFI_SUCCESS;
 	unsigned long name_length;
+	dma_addr_t cmd_buf_dma;
+	size_t cmd_buf_size;
+	void *cmd_buf;
 	size_t name_offs;
 	size_t guid_offs;
 	size_t data_offs;
 	size_t req_size;
+	size_t req_offs;
+	size_t rsp_offs;
 	ssize_t status;
 
 	if (!name || !guid)
@@ -450,17 +481,19 @@ static efi_status_t qsee_uefi_set_variable(struct qcuefi_client *qcuefi, const e
 		__array_offs(u8, data_size, &data_offs)
 	);
 
-	req_data = kzalloc(req_size, GFP_KERNEL);
-	if (!req_data) {
+	cmd_buf_size = qcuefi_buf_align_fields(
+		__reqdata_offs(req_size, &req_offs)
+		__reqdata_offs(sizeof(*rsp_data), &rsp_offs)
+	);
+
+	cmd_buf = qseecom_dma_alloc(qcuefi->client, cmd_buf_size, &cmd_buf_dma, GFP_KERNEL);
+	if (!cmd_buf) {
 		efi_status = EFI_OUT_OF_RESOURCES;
 		goto out;
 	}
 
-	rsp_data = kzalloc(sizeof(*rsp_data), GFP_KERNEL);
-	if (!rsp_data) {
-		efi_status = EFI_OUT_OF_RESOURCES;
-		goto out_free_req;
-	}
+	req_data = cmd_buf + req_offs;
+	rsp_data = cmd_buf + rsp_offs;
 
 	req_data->command_id = QSEE_CMD_UEFI_SET_VARIABLE;
 	req_data->attributes = attributes;
@@ -483,8 +516,9 @@ static efi_status_t qsee_uefi_set_variable(struct qcuefi_client *qcuefi, const e
 	if (data_size)
 		memcpy(((void *)req_data) + req_data->data_offset, data, req_data->data_size);
 
-	status = qcom_qseecom_app_send(qcuefi->client, req_data, req_size, rsp_data,
-				       sizeof(*rsp_data));
+	status = qcom_qseecom_app_send(qcuefi->client,
+				       cmd_buf_dma + req_offs, req_size,
+				       cmd_buf_dma + rsp_offs, sizeof(*rsp_data));
 	if (status) {
 		efi_status = EFI_DEVICE_ERROR;
 		goto out_free;
@@ -507,9 +541,7 @@ static efi_status_t qsee_uefi_set_variable(struct qcuefi_client *qcuefi, const e
 	}
 
 out_free:
-	kfree(rsp_data);
-out_free_req:
-	kfree(req_data);
+	qseecom_dma_free(qcuefi->client, cmd_buf_size, cmd_buf, cmd_buf_dma);
 out:
 	return efi_status;
 }
@@ -521,10 +553,15 @@ static efi_status_t qsee_uefi_get_next_variable(struct qcuefi_client *qcuefi,
 	struct qsee_req_uefi_get_next_variable *req_data;
 	struct qsee_rsp_uefi_get_next_variable *rsp_data;
 	efi_status_t efi_status = EFI_SUCCESS;
+	dma_addr_t cmd_buf_dma;
+	size_t cmd_buf_size;
+	void *cmd_buf;
 	size_t guid_offs;
 	size_t name_offs;
 	size_t req_size;
 	size_t rsp_size;
+	size_t req_offs;
+	size_t rsp_offs;
 	ssize_t status;
 
 	if (!name_size || !name || !guid)
@@ -545,17 +582,19 @@ static efi_status_t qsee_uefi_get_next_variable(struct qcuefi_client *qcuefi,
 		__array(*name, *name_size / sizeof(*name))
 	);
 
-	req_data = kzalloc(req_size, GFP_KERNEL);
-	if (!req_data) {
+	cmd_buf_size = qcuefi_buf_align_fields(
+		__reqdata_offs(req_size, &req_offs)
+		__reqdata_offs(rsp_size, &rsp_offs)
+	);
+
+	cmd_buf = qseecom_dma_alloc(qcuefi->client, cmd_buf_size, &cmd_buf_dma, GFP_KERNEL);
+	if (!cmd_buf) {
 		efi_status = EFI_OUT_OF_RESOURCES;
 		goto out;
 	}
 
-	rsp_data = kzalloc(rsp_size, GFP_KERNEL);
-	if (!rsp_data) {
-		efi_status = EFI_OUT_OF_RESOURCES;
-		goto out_free_req;
-	}
+	req_data = cmd_buf + req_offs;
+	rsp_data = cmd_buf + rsp_offs;
 
 	req_data->command_id = QSEE_CMD_UEFI_GET_NEXT_VARIABLE;
 	req_data->guid_offset = guid_offs;
@@ -572,7 +611,9 @@ static efi_status_t qsee_uefi_get_next_variable(struct qcuefi_client *qcuefi,
 		goto out_free;
 	}
 
-	status = qcom_qseecom_app_send(qcuefi->client, req_data, req_size, rsp_data, rsp_size);
+	status = qcom_qseecom_app_send(qcuefi->client,
+				       cmd_buf_dma + req_offs, req_size,
+				       cmd_buf_dma + rsp_offs, rsp_size);
 	if (status) {
 		efi_status = EFI_DEVICE_ERROR;
 		goto out_free;
@@ -645,9 +686,7 @@ static efi_status_t qsee_uefi_get_next_variable(struct qcuefi_client *qcuefi,
 	}
 
 out_free:
-	kfree(rsp_data);
-out_free_req:
-	kfree(req_data);
+	qseecom_dma_free(qcuefi->client, cmd_buf_size, cmd_buf, cmd_buf_dma);
 out:
 	return efi_status;
 }
@@ -659,26 +698,34 @@ static efi_status_t qsee_uefi_query_variable_info(struct qcuefi_client *qcuefi,
 	struct qsee_req_uefi_query_variable_info *req_data;
 	struct qsee_rsp_uefi_query_variable_info *rsp_data;
 	efi_status_t efi_status = EFI_SUCCESS;
+	dma_addr_t cmd_buf_dma;
+	size_t cmd_buf_size;
+	void *cmd_buf;
+	size_t req_offs;
+	size_t rsp_offs;
 	int status;
 
-	req_data = kzalloc(sizeof(*req_data), GFP_KERNEL);
-	if (!req_data) {
+	cmd_buf_size = qcuefi_buf_align_fields(
+		__reqdata_offs(sizeof(*req_data), &req_offs)
+		__reqdata_offs(sizeof(*rsp_data), &rsp_offs)
+	);
+
+	cmd_buf = qseecom_dma_alloc(qcuefi->client, cmd_buf_size, &cmd_buf_dma, GFP_KERNEL);
+	if (!cmd_buf) {
 		efi_status = EFI_OUT_OF_RESOURCES;
 		goto out;
 	}
 
-	rsp_data = kzalloc(sizeof(*rsp_data), GFP_KERNEL);
-	if (!rsp_data) {
-		efi_status = EFI_OUT_OF_RESOURCES;
-		goto out_free_req;
-	}
+	req_data = cmd_buf + req_offs;
+	rsp_data = cmd_buf + rsp_offs;
 
 	req_data->command_id = QSEE_CMD_UEFI_QUERY_VARIABLE_INFO;
 	req_data->attributes = attr;
 	req_data->length = sizeof(*req_data);
 
-	status = qcom_qseecom_app_send(qcuefi->client, req_data, sizeof(*req_data), rsp_data,
-				       sizeof(*rsp_data));
+	status = qcom_qseecom_app_send(qcuefi->client,
+				       cmd_buf_dma + req_offs, sizeof(*req_data),
+				       cmd_buf_dma + rsp_offs, sizeof(*rsp_data));
 	if (status) {
 		efi_status = EFI_DEVICE_ERROR;
 		goto out_free;
@@ -711,9 +758,7 @@ static efi_status_t qsee_uefi_query_variable_info(struct qcuefi_client *qcuefi,
 		*max_variable_size = rsp_data->max_variable_size;
 
 out_free:
-	kfree(rsp_data);
-out_free_req:
-	kfree(req_data);
+	qseecom_dma_free(qcuefi->client, cmd_buf_size, cmd_buf, cmd_buf_dma);
 out:
 	return efi_status;
 }
diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c
index 520de9b5633a..90283f160a22 100644
--- a/drivers/firmware/qcom/qcom_scm.c
+++ b/drivers/firmware/qcom/qcom_scm.c
@@ -1576,9 +1576,9 @@ EXPORT_SYMBOL_GPL(qcom_scm_qseecom_app_get_id);
 /**
  * qcom_scm_qseecom_app_send() - Send to and receive data from a given QSEE app.
  * @app_id:   The ID of the target app.
- * @req:      Request buffer sent to the app (must be DMA-mappable).
+ * @req:      DMA address of the request buffer sent to the app.
  * @req_size: Size of the request buffer.
- * @rsp:      Response buffer, written to by the app (must be DMA-mappable).
+ * @rsp:      DMA address of the response buffer, written to by the app.
  * @rsp_size: Size of the response buffer.
  *
  * Sends a request to the QSEE app associated with the given ID and read back
@@ -1589,33 +1589,13 @@ EXPORT_SYMBOL_GPL(qcom_scm_qseecom_app_get_id);
  *
  * Return: Zero on success, nonzero on failure.
  */
-int qcom_scm_qseecom_app_send(u32 app_id, void *req, size_t req_size, void *rsp,
-			      size_t rsp_size)
+int qcom_scm_qseecom_app_send(u32 app_id, dma_addr_t req, size_t req_size,
+			      dma_addr_t rsp, size_t rsp_size)
 {
 	struct qcom_scm_qseecom_resp res = {};
 	struct qcom_scm_desc desc = {};
-	dma_addr_t req_phys;
-	dma_addr_t rsp_phys;
 	int status;
 
-	/* Map request buffer */
-	req_phys = dma_map_single(__scm->dev, req, req_size, DMA_TO_DEVICE);
-	status = dma_mapping_error(__scm->dev, req_phys);
-	if (status) {
-		dev_err(__scm->dev, "qseecom: failed to map request buffer\n");
-		return status;
-	}
-
-	/* Map response buffer */
-	rsp_phys = dma_map_single(__scm->dev, rsp, rsp_size, DMA_FROM_DEVICE);
-	status = dma_mapping_error(__scm->dev, rsp_phys);
-	if (status) {
-		dma_unmap_single(__scm->dev, req_phys, req_size, DMA_TO_DEVICE);
-		dev_err(__scm->dev, "qseecom: failed to map response buffer\n");
-		return status;
-	}
-
-	/* Set up SCM call data */
 	desc.owner = QSEECOM_TZ_OWNER_TZ_APPS;
 	desc.svc = QSEECOM_TZ_SVC_APP_ID_PLACEHOLDER;
 	desc.cmd = QSEECOM_TZ_CMD_APP_SEND;
@@ -1623,18 +1603,13 @@ int qcom_scm_qseecom_app_send(u32 app_id, void *req, size_t req_size, void *rsp,
 				     QCOM_SCM_RW, QCOM_SCM_VAL,
 				     QCOM_SCM_RW, QCOM_SCM_VAL);
 	desc.args[0] = app_id;
-	desc.args[1] = req_phys;
+	desc.args[1] = req;
 	desc.args[2] = req_size;
-	desc.args[3] = rsp_phys;
+	desc.args[3] = rsp;
 	desc.args[4] = rsp_size;
 
-	/* Perform call */
 	status = qcom_scm_qseecom_call(&desc, &res);
 
-	/* Unmap buffers */
-	dma_unmap_single(__scm->dev, rsp_phys, rsp_size, DMA_FROM_DEVICE);
-	dma_unmap_single(__scm->dev, req_phys, req_size, DMA_TO_DEVICE);
-
 	if (status)
 		return status;