On Thu, 28 Mar 2024 at 21:39, Jens Wiklander jens.wiklander@linaro.org wrote:
On Fri, Mar 1, 2024 at 11:28 AM Sumit Garg sumit.garg@linaro.org wrote:
Hi Jens,
On Tue, 27 Feb 2024 at 21:01, Jens Wiklander jens.wiklander@linaro.org wrote:
Adds support in the OP-TEE drivers (both SMC and FF-A ABIs) to probe and use an RPMB device via the RPBM subsystem instead of passing the RPMB
s/RPBM/RPMB/
Here are other places too in this patch-set.
frames via tee-supplicant in user space. A fallback mechanism is kept to route RPMB frames via tee-supplicant if the RPMB subsystem isn't available.
The OP-TEE RPC ABI is extended to support iterating over all RPMB devices until one is found with the expected RPMB key already programmed.
I would appreciate it if you could add a link to OP-TEE OS changes in the cover-letter although I have found them here [1].
[1] https://github.com/jenswi-linaro/optee_os/commits/rpmb_probe/
OK, I'll add a link in the coverletter of the next patch set.
Signed-off-by: Jens Wiklander jens.wiklander@linaro.org
drivers/tee/optee/core.c | 55 +++++++ drivers/tee/optee/ffa_abi.c | 7 + drivers/tee/optee/optee_private.h | 16 ++ drivers/tee/optee/optee_rpc_cmd.h | 35 +++++ drivers/tee/optee/rpc.c | 233 ++++++++++++++++++++++++++++++ drivers/tee/optee/smc_abi.c | 6 + 6 files changed, 352 insertions(+)
diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index 3aed554bc8d8..6b32d3e7865b 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -11,6 +11,7 @@ #include <linux/io.h> #include <linux/mm.h> #include <linux/module.h> +#include <linux/rpmb.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/tee_drv.h> @@ -80,6 +81,57 @@ void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm, shm->pages = NULL; }
+static void optee_rpmb_scan(struct work_struct *work) +{
struct optee *optee = container_of(work, struct optee, scan_rpmb_work);bool scan_done = false;u32 res;do {mutex_lock(&optee->rpmb_dev_mutex);/* No need to rescan if we haven't started scanning yet */optee->rpmb_dev_request_rescan = false;mutex_unlock(&optee->rpmb_dev_mutex);res = optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB);if (res && res != TEE_ERROR_STORAGE_NOT_AVAILABLE)I suppose this hasn't been tested for a negative case since optee_enumerate_devices() won't return this error code (see [2]). However, I would prefer to use GP Client error code: TEEC_ERROR_ITEM_NOT_FOUND here instead.
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/driv...
I prefer TEE_ERROR_STORAGE_NOT_AVAILABLE since that's the code GP says a TA should get when storage is unavailable. TEEC_ERROR_ITEM_NOT_FOUND is less specific. Anyway, I'll need to translate the code in get_devices().
Okay, that's fair.
pr_info("Scanning for RPMB device: res %#x\n", res);mutex_lock(&optee->rpmb_dev_mutex);/** If another RPMB device came online while scanning, scan one* more time, unless we have already found an RPBM device.*/scan_done = (optee->rpmb_dev ||I suppose we don't need to check for optee->rpmb_dev here since a successful return from optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB) would ensure that the RPMB device has been found.
That makes sense, I'll check the return value instead.
!optee->rpmb_dev_request_rescan);optee->rpmb_dev_request_rescan = false;optee->rpmb_dev_scan_in_progress = !scan_done;mutex_unlock(&optee->rpmb_dev_mutex);} while (!scan_done);+}
+void optee_rpmb_intf_add_rdev(struct rpmb_interface *intf,
struct rpmb_dev *rdev)+{
struct optee *optee = container_of(intf, struct optee, rpmb_intf);bool queue_work = true;mutex_lock(&optee->rpmb_dev_mutex);if (optee->rpmb_dev || optee->rpmb_dev_scan_in_progress) {Can we use work_pending() instead of our custom optee->rpmb_dev_scan_in_progress flag?
That seems racy, or am I missing something?
You are right and even work_busy() is documented to provide unreliable results. So I am rather thinking about just queuing the work and thereby scanning for devices unconditionally. I suppose the extra logic to check if we don't try to register duplicate devices can go under optee_enumerate_devices().
queue_work = false;if (optee->rpmb_dev_scan_in_progress)optee->rpmb_dev_request_rescan = true;}if (queue_work)optee->rpmb_dev_scan_in_progress = true;mutex_unlock(&optee->rpmb_dev_mutex);if (queue_work) {INIT_WORK(&optee->scan_rpmb_work, optee_rpmb_scan);schedule_work(&optee->scan_rpmb_work);Can we reuse optee->scan_bus_work rather than introducing a new one here?
No, both may be active at the same time.
Actually both of them are using system_wq underneath, so it shouldn't be a problem if both are active at the same time as they can be queued simultaneously, right?
We'd have to merge optee_rpmb_scan() and optee_bus_scan(), but I'm not sure it's worth it.
}+}
static void optee_bus_scan(struct work_struct *work) { WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP)); @@ -161,6 +213,7 @@ void optee_release_supp(struct tee_context *ctx)
void optee_remove_common(struct optee *optee) {
rpmb_interface_unregister(&optee->rpmb_intf); /* Unregister OP-TEE specific client devices on TEE bus */ optee_unregister_devices();@@ -177,6 +230,8 @@ void optee_remove_common(struct optee *optee) tee_shm_pool_free(optee->pool); optee_supp_uninit(&optee->supp); mutex_destroy(&optee->call_queue.mutex);
rpmb_dev_put(optee->rpmb_dev);mutex_destroy(&optee->rpmb_dev_mutex);}
static int smc_abi_rc; diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c index ecb5eb079408..befe19ecc30a 100644 --- a/drivers/tee/optee/ffa_abi.c +++ b/drivers/tee/optee/ffa_abi.c @@ -7,6 +7,7 @@
#include <linux/arm_ffa.h> #include <linux/errno.h> +#include <linux/rpmb.h> #include <linux/scatterlist.h> #include <linux/sched.h> #include <linux/slab.h> @@ -934,6 +935,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) optee_cq_init(&optee->call_queue, 0); optee_supp_init(&optee->supp); optee_shm_arg_cache_init(optee, arg_cache_flags);
mutex_init(&optee->rpmb_dev_mutex); ffa_dev_set_drvdata(ffa_dev, optee); ctx = teedev_open(optee->teedev); if (IS_ERR(ctx)) {@@ -955,6 +957,8 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) if (rc) goto err_unregister_devices;
optee->rpmb_intf.add_rdev = optee_rpmb_intf_add_rdev;rpmb_interface_register(&optee->rpmb_intf); pr_info("initialized driver\n"); return 0;@@ -968,6 +972,9 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) teedev_close_context(ctx); err_rhashtable_free: rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
rpmb_dev_put(optee->rpmb_dev);mutex_destroy(&optee->rpmb_dev_mutex);rpmb_interface_unregister(&optee->rpmb_intf); optee_supp_uninit(&optee->supp); mutex_destroy(&optee->call_queue.mutex); mutex_destroy(&optee->ffa.mutex);diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index 7a5243c78b55..1e4c33baef43 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -8,6 +8,7 @@
#include <linux/arm-smccc.h> #include <linux/rhashtable.h> +#include <linux/rpmb.h> #include <linux/semaphore.h> #include <linux/tee_drv.h> #include <linux/types.h> @@ -20,11 +21,13 @@ /* Some Global Platform error codes used in this driver */ #define TEEC_SUCCESS 0x00000000 #define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006 +#define TEEC_ERROR_ITEM_NOT_FOUND 0xFFFF0008 #define TEEC_ERROR_NOT_SUPPORTED 0xFFFF000A #define TEEC_ERROR_COMMUNICATION 0xFFFF000E #define TEEC_ERROR_OUT_OF_MEMORY 0xFFFF000C #define TEEC_ERROR_BUSY 0xFFFF000D #define TEEC_ERROR_SHORT_BUFFER 0xFFFF0010 +#define TEE_ERROR_STORAGE_NOT_AVAILABLE 0xF0100003
#define TEEC_ORIGIN_COMMS 0x00000002
@@ -197,6 +200,8 @@ struct optee_ops {
- @notif: notification synchronization struct
- @supp: supplicant synchronization struct for RPC to supplicant
- @pool: shared memory pool
- @mutex: mutex protecting @rpmb_dev
- @rpmb_dev: current RPMB device or NULL
- @rpc_param_count: If > 0 number of RPC parameters to make room for
- @scan_bus_done flag if device registation was already done.
- @scan_bus_work workq to scan optee bus and register optee drivers
@@ -215,9 +220,17 @@ struct optee { struct optee_notif notif; struct optee_supp supp; struct tee_shm_pool *pool;
/* Protects rpmb_dev pointer and rpmb_dev_* */struct mutex rpmb_dev_mutex;Given my comments above, do we really need this mutex?
I don't see how we can do without the mutex.
See if it is possible with the above mentioned approach.
-Sumit