[PATCHv7 2/3] optee: enable support for multi-stage bus enumeration

From: Maxim Uvarov
Date: Thu Jun 04 2020 - 11:04:03 EST

Some drivers (like ftpm) can operate only after tee-supplicant
runs because of tee-supplicant provides things like storage
services (rpmb, shm). ÂThis patch splits probe of non tee-supplicant
dependable drivers to the early stage, and after tee-supplicant run
probe other drivers.

Signed-off-by: Maxim Uvarov <maxim.uvarov@xxxxxxxxxx>
Suggested-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
Suggested-by: Arnd Bergmann <arnd@xxxxxxxxxx>
Reviewed-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
---
drivers/tee/optee/core.c | 27 ++++++++++++++++++++++++---
drivers/tee/optee/device.c | 29 +++++++++++------------------
drivers/tee/optee/optee_private.h | 10 +++++++++-
3 files changed, 44 insertions(+), 22 deletions(-)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index 99698b8a3a74..b373b1b08b6d 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -17,6 +17,7 @@
#include <linux/tee_drv.h>
#include <linux/types.h>
#include <linux/uaccess.h>
+#include <linux/workqueue.h>
#include "optee_private.h"
#include "optee_smc.h"
#include "shm_pool.h"
@@ -218,6 +219,11 @@ static void optee_get_version(struct tee_device *teedev,
*vers = v;
}

+static void optee_bus_scan(struct work_struct *work)
+{
+ WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
+}
+
static int optee_open(struct tee_context *ctx)
{
struct optee_context_data *ctxdata;
@@ -241,8 +247,18 @@ static int optee_open(struct tee_context *ctx)
kfree(ctxdata);
return -EBUSY;
}
- }

+ if (!optee->scan_bus_done) {
+ INIT_WORK(&optee->scan_bus_work, optee_bus_scan);
+ optee->scan_bus_wq = create_workqueue("optee_bus_scan");
+ if (!optee->scan_bus_wq) {
+ kfree(ctxdata);
+ return -ECHILD;
+ }
+ queue_work(optee->scan_bus_wq, &optee->scan_bus_work);
+ optee->scan_bus_done = true;
+ }
+ }
mutex_init(&ctxdata->mutex);
INIT_LIST_HEAD(&ctxdata->sess_list);

@@ -296,8 +312,13 @@ static void optee_release(struct tee_context *ctx)

ctx->data = NULL;

- if (teedev == optee->supp_teedev)
+ if (teedev == optee->supp_teedev) {
+ if (optee->scan_bus_wq) {
+ destroy_workqueue(optee->scan_bus_wq);
+ optee->scan_bus_wq = NULL;
+ }
optee_supp_release(&optee->supp);
+ }
}

static const struct tee_driver_ops optee_ops = {
@@ -675,7 +696,7 @@ static int optee_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, optee);

- rc = optee_enumerate_devices();
+ rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
if (rc) {
optee_remove(pdev);
return rc;
diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c
index 14d335cf8d34..663c4c90a063 100644
--- a/drivers/tee/optee/device.c
+++ b/drivers/tee/optee/device.c
@@ -11,18 +11,6 @@
#include <linux/uuid.h>
#include "optee_private.h"

-/*
- * Get device UUIDs
- *
- * [out] memref[0] Array of device UUIDs
- *
- * Return codes:
- * TEE_SUCCESS - Invoke command success
- * TEE_ERROR_BAD_PARAMETERS - Incorrect input param
- * TEE_ERROR_SHORT_BUFFER - Output buffer size less than required
- */
-#define PTA_CMD_GET_DEVICES 0x0
-
static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
{
if (ver->impl_id == TEE_IMPL_ID_OPTEE)
@@ -32,7 +20,8 @@ static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
}

static int get_devices(struct tee_context *ctx, u32 session,
- struct tee_shm *device_shm, u32 *shm_size)
+ struct tee_shm *device_shm, u32 *shm_size,
+ u32 func)
{
int ret = 0;
struct tee_ioctl_invoke_arg inv_arg;
@@ -41,8 +30,7 @@ static int get_devices(struct tee_context *ctx, u32 session,
memset(&inv_arg, 0, sizeof(inv_arg));
memset(&param, 0, sizeof(param));

- /* Invoke PTA_CMD_GET_DEVICES function */
- inv_arg.func = PTA_CMD_GET_DEVICES;
+ inv_arg.func = func;
inv_arg.session = session;
inv_arg.num_params = 4;

@@ -90,7 +78,7 @@ static int optee_register_device(const uuid_t *device_uuid)
return rc;
}

-int optee_enumerate_devices(void)
+static int __optee_enumerate_devices(u32 func)
{
const uuid_t pta_uuid =
UUID_INIT(0x7011a688, 0xddde, 0x4053,
@@ -121,7 +109,7 @@ int optee_enumerate_devices(void)
goto out_ctx;
}

- rc = get_devices(ctx, sess_arg.session, NULL, &shm_size);
+ rc = get_devices(ctx, sess_arg.session, NULL, &shm_size, func);
if (rc < 0 || !shm_size)
goto out_sess;

@@ -133,7 +121,7 @@ int optee_enumerate_devices(void)
goto out_sess;
}

- rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size);
+ rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size, func);
if (rc < 0)
goto out_shm;

@@ -161,3 +149,8 @@ int optee_enumerate_devices(void)

return rc;
}
+
+int optee_enumerate_devices(u32 func)
+{
+ return __optee_enumerate_devices(func);
+}
diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
index d9c5037b4e03..8b71839a357e 100644
--- a/drivers/tee/optee/optee_private.h
+++ b/drivers/tee/optee/optee_private.h
@@ -78,6 +78,9 @@ struct optee_supp {
* @memremaped_shm virtual address of memory in shared memory pool
* @sec_caps: secure world capabilities defined by
* OPTEE_SMC_SEC_CAP_* in optee_smc.h
+ * @scan_bus_done flag if device registation was already done.
+ * @scan_bus_wq workqueue to scan optee bus and register optee drivers
+ * @scan_bus_work workq to scan optee bus and register optee drivers
*/
struct optee {
struct tee_device *supp_teedev;
@@ -89,6 +92,9 @@ struct optee {
struct tee_shm_pool *pool;
void *memremaped_shm;
u32 sec_caps;
+ bool scan_bus_done;
+ struct workqueue_struct *scan_bus_wq;
+ struct work_struct scan_bus_work;
};

struct optee_session {
@@ -173,7 +179,9 @@ void optee_free_pages_list(void *array, size_t num_entries);
void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages,
size_t page_offset);

-int optee_enumerate_devices(void);
+#define PTA_CMD_GET_DEVICES 0x0
+#define PTA_CMD_GET_DEVICES_SUPP 0x1
+int optee_enumerate_devices(u32 func);

/*
* Small helpers
--
2.17.1