kernel/linux.git/include/linux/tee_drv.h, branch v6.12.80

driver core: have match() callback in struct bus_type take a const *

2024-07-03T13:16:54+00:00

In the match() callback, the struct device_driver * should not be changed, so change the function callback to be a const *. This is one step of many towards making the driver core safe to have struct device_driver in read-only memory. Because the match() callback is in all busses, all busses are modified to handle this properly. This does entail switching some container_of() calls to container_of_const() to properly handle the constant *. For some busses, like PCI and USB and HV, the const * is cast away in the match callback as those busses do want to modify those structures at this point in time (they have a local lock in the driver structure.) That will have to be changed in the future if they wish to have their struct device * in read-only-memory. Cc: Rafael J. Wysocki Reviewed-by: Alex Elder Acked-by: Sumit Garg Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh Signed-off-by: Greg Kroah-Hartman

tee: Refactor TEE subsystem header files

2024-04-03T07:19:31+00:00

Since commit 25559c22cef8 ("tee: add kernel internal client interface"), it has been a common include/linux/tee_drv.h header file which is shared to hold TEE subsystem internal bits along with the APIs exposed to the TEE client drivers. However, this practice is prone to TEE subsystem internal APIs abuse and especially so with the new TEE implementation drivers being added to reuse existing functionality. In order to address this split TEE subsystem internal bits as a separate header file: include/linux/tee_core.h which should be the one used by TEE implementation drivers. With that include/linux/tee_drv.h lists only APIs exposed by TEE subsystem to the TEE client drivers. Signed-off-by: Sumit Garg Signed-off-by: Balint Dobszay Signed-off-by: Jens Wiklander

tee: make tee_bus_type const

2024-03-04T16:25:09+00:00

Since commit d492cc2573a0 ("driver core: device.h: make struct bus_type a const *"), the driver core can properly handle constant struct bus_type, move the tee_bus_type variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman Suggested-by: Greg Kroah-Hartman Signed-off-by: Ricardo B. Marliere Reviewed-by: Sumit Garg Reviewed-by: Greg Kroah-Hartman Signed-off-by: Jens Wiklander Signed-off-by: Arnd Bergmann

tee: system session

2023-11-17T14:48:03+00:00

Adds kernel client API function tee_client_system_session() for a client to request a system service entry in TEE context. This feature is needed to prevent a system deadlock when several TEE client applications invoke TEE, consuming all TEE thread contexts available in the secure world. The deadlock can happen in the OP-TEE driver for example if all these TEE threads issue an RPC call from TEE to Linux OS to access an eMMC RPMB partition (TEE secure storage) which device clock or regulator controller is accessed through an OP-TEE SCMI services. In that case, Linux SCMI driver must reach OP-TEE SCMI service without waiting until one of the consumed TEE threads is freed. Reviewed-by: Sumit Garg Co-developed-by: Jens Wiklander Signed-off-by: Etienne Carriere Signed-off-by: Jens Wiklander

tee: remove tee_shm_va2pa() and tee_shm_pa2va()

2022-04-26T08:16:48+00:00

We should not need to index into SHMs based on absolute VA/PA. These functions are not used and this kind of usage should not be encouraged anyway. Remove these functions. Signed-off-by: Andrew Davis Reviewed-by: Sumit Garg Signed-off-by: Jens Wiklander

tee: refactor TEE_SHM_* flags

2022-02-16T06:49:41+00:00

Removes the redundant TEE_SHM_DMA_BUF, TEE_SHM_EXT_DMA_BUF, TEE_SHM_MAPPED and TEE_SHM_KERNEL_MAPPED flags. TEE_SHM_REGISTER is renamed to TEE_SHM_DYNAMIC in order to better match its usage. Assigns new values to the remaining flags to void gaps. Reviewed-by: Sumit Garg Signed-off-by: Jens Wiklander

tee: replace tee_shm_register()

2022-02-16T06:49:41+00:00

tee_shm_register() is replaced by the previously introduced functions tee_shm_register_user_buf() and tee_shm_register_kernel_buf(). Since there are not external callers left we can remove tee_shm_register() and refactor the remains. Reviewed-by: Sumit Garg Signed-off-by: Jens Wiklander

tee: add tee_shm_register_{user,kernel}_buf()

2022-02-16T06:49:41+00:00

Adds the two new functions tee_shm_register_user_buf() and tee_shm_register_kernel_buf() which should be used instead of the old tee_shm_register(). This avoids having the caller supplying the flags parameter which exposes a bit more than desired of the internals of the TEE subsystem. Reviewed-by: Sumit Garg Signed-off-by: Jens Wiklander

tee: replace tee_shm_alloc()

2022-02-16T06:49:41+00:00

tee_shm_alloc() is replaced by three new functions, tee_shm_alloc_user_buf() - for user mode allocations, replacing passing the flags TEE_SHM_MAPPED | TEE_SHM_DMA_BUF tee_shm_alloc_kernel_buf() - for kernel mode allocations, slightly optimized compared to using the flags TEE_SHM_MAPPED | TEE_SHM_DMA_BUF. tee_shm_alloc_priv_buf() - primarily for TEE driver internal use. This also makes the interface easier to use as we can get rid of the somewhat hard to use flags parameter. The TEE subsystem and the TEE drivers are updated to use the new functions instead. Reviewed-by: Sumit Garg Signed-off-by: Jens Wiklander

tee: simplify shm pool handling

2022-02-16T06:49:41+00:00

Replaces the shared memory pool based on two pools with a single pool. The alloc() function pointer in struct tee_shm_pool_ops gets another parameter, align. This makes it possible to make less than page aligned allocations from the optional reserved shared memory pool while still making user space allocations page aligned. With in practice unchanged behaviour using only a single pool for bookkeeping. The allocation algorithm in the static OP-TEE shared memory pool is changed from best-fit to first-fit since only the latter supports an alignment parameter. The best-fit algorithm was previously the default choice and not a conscious one. The optee and amdtee drivers are updated as needed to work with this changed pool handling. This also removes OPTEE_SHM_NUM_PRIV_PAGES which becomes obsolete with this change as the private pages can be mixed with the payload pages. The OP-TEE driver changes minimum alignment for argument struct from 8 bytes to 512 bytes. A typical OP-TEE private shm allocation is 224 bytes (argument struct with 6 parameters, needed for open session). So with an alignment of 512 well waste a bit more than 50%. Before this we had a single page reserved for this so worst case usage compared to that would be 3 pages instead of 1 page. However, this worst case only occurs if there is a high pressure from multiple threads on secure world. All in all this should scale up and down better than fixed boundaries. Reviewed-by: Sumit Garg Signed-off-by: Jens Wiklander