Commit Graph

14 Commits

Author SHA1 Message Date
Arnd Bergmann 01537a078b firmware: arm_ffa: Remove unused 'compat_version' variable
The newly added ffa_compatible_version_find() function causes a
build warning because of a variable that is never used:

drivers/firmware/arm_ffa/driver.c:180:6: error: unused variable 'compat_version' [-Werror,-Wunused-variable]
        u32 compat_version;

Link: https://lore.kernel.org/r/20211026083400.3444946-1-arnd@kernel.org
Fixes: 8e3f9da608 ("firmware: arm_ffa: Handle compatibility with different firmware versions")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-10-26 12:46:15 +01:00
Marc Bonnici 82a8daaecf firmware: arm_ffa: Add support for MEM_LEND
As part of the FF-A spec, an endpoint is allowed to transfer access of,
or lend, a memory region to one or more borrowers.

Extend the existing memory sharing implementation to support
FF-A MEM_LEND functionality and expose this to other kernel drivers.

Note that upon a successful MEM_LEND request the caller must ensure that
the memory region specified is not accessed until a successful
MEM_RECALIM call has been made. On systems with a hypervisor present
this will been enforced, however on systems without a hypervisor the
responsibility falls to the calling kernel driver to prevent access.

Link: https://lore.kernel.org/r/20211015165742.2513065-1-marc.bonnici@arm.com
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Marc Bonnici <marc.bonnici@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-10-18 13:11:06 +01:00
Sudeep Holla 8e3f9da608 firmware: arm_ffa: Handle compatibility with different firmware versions
The driver currently just support v1.0 of Arm FFA specification. It also
expects the firmware implementation to match the same and bail out if it
doesn't match. This is causing issue when running with higher version of
firmware implementation(e.g. v1.1 which will released soon).

In order to support compatibility with different firmware versions, let
us add additional checks and find the compatible version the driver can
work with.

Link: https://lore.kernel.org/r/20211013091127.990992-1-sudeep.holla@arm.com
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-10-18 13:10:38 +01:00
Sudeep Holla eb7b52e6db firmware: arm_ffa: Fix __ffa_devices_unregister
When arm_ffa firmware driver module is unloaded or removed we call
__ffa_devices_unregister on all the devices on the ffa bus. It must
unregister all the devices instead it is currently just releasing the
devices without unregistering. That is pure wrong as when we try to
load the module back again, it will result in the kernel crash something
like below.

-->8
 CPU: 2 PID: 232 Comm: modprobe Not tainted 5.15.0-rc2+ #169
 Hardware name: FVP Base RevC (DT)
 Call trace:
  dump_backtrace+0x0/0x1cc
  show_stack+0x18/0x64
  dump_stack_lvl+0x64/0x7c
  dump_stack+0x18/0x38
  sysfs_create_dir_ns+0xe4/0x140
  kobject_add_internal+0x170/0x358
  kobject_add+0x94/0x100
  device_add+0x178/0x5f0
  device_register+0x20/0x30
  ffa_device_register+0x80/0xcc [ffa_module]
  ffa_setup_partitions+0x7c/0x108 [ffa_module]
  init_module+0x290/0x2dc [ffa_module]
  do_one_initcall+0xbc/0x230
  do_init_module+0x58/0x304
  load_module+0x15e0/0x1f68
  __arm64_sys_finit_module+0xb8/0xf4
  invoke_syscall+0x44/0x140
  el0_svc_common+0xb4/0xf0
  do_el0_svc+0x24/0x80
  el0_svc+0x20/0x50
  el0t_64_sync_handler+0x84/0xe4
  el0t_64_sync+0x1a0/0x1a4
 kobject_add_internal failed for arm-ffa-8001 with -EEXIST, don't try to
 register things with the same name in the same directory.
----

Fix the issue by calling device_unregister in __ffa_devices_unregister
which will also take care of calling device_release(which is mapped to
ffa_release_device)

Link: https://lore.kernel.org/r/20210924092859.3057562-2-sudeep.holla@arm.com
Fixes: e781858488 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration")
Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-10-05 10:39:47 +01:00
Sudeep Holla 244f5d597e firmware: arm_ffa: Add missing remove callback to ffa_bus_type
Currently the arm_ffa firmware driver can be built as module and hence
all the users of FFA driver. If any driver on the ffa bus is removed or
unregistered, the remove callback on all the device bound to the driver
being removed should be callback. For that to happen, we must register
a remove callback on the ffa_bus which is currently missing. This results
in the probe getting called again without the previous remove callback
on a device which may result in kernel crash.

Fix the issue by registering the remove callback on the FFA bus.

Link: https://lore.kernel.org/r/20210924092859.3057562-1-sudeep.holla@arm.com
Fixes: e781858488 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration")
Reported-by: Jens Wiklander <jens.wiklander@linaro.org>
Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-10-05 10:39:46 +01:00
Sudeep Holla dd925db6f0 firmware: arm_ffa: Fix a possible ffa_linux_errmap buffer overflow
The ffa_linux_errmap buffer access index is supposed to range from 0-8
but it ranges from 1-9 instead. It reads one element out of bounds. It
also changes the success into -EINVAL though ffa_to_linux_errno is never
used in case of success, it is expected to work for success case too.

It is slightly confusing code as the negative of the error code
is used as index to the buffer. Fix it by negating it at the start and
make it more readable.

Link: https://lore.kernel.org/r/20210707134739.1869481-1-sudeep.holla@arm.com
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-07-12 14:20:08 +01:00
Sudeep Holla ba684a31d3 firmware: arm_ffa: Fix the comment style
clang produces the following warning:

    drivers/firmware/arm_ffa/driver.c:123: warning: expecting
    prototype for FF(). Prototype was for FFA_PAGE_SIZE() instead

    This comment starts with '/**', but isn't a kernel-doc comment.
    Refer Documentation/doc-guide/kernel-doc.rst

Fix the same by removing the kernel-doc style comment here.

Link: https://lore.kernel.org/r/20210622162202.3485866-1-sudeep.holla@arm.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-07-12 14:20:08 +01:00
Uwe Kleine-König e362547add firmware: arm_ffa: Simplify probe function
When the driver core calls the probe callback it already checked that
the devices match, so there is no need to call the match callback again.

Link: https://lore.kernel.org/r/20210621201652.127611-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-07-12 14:20:07 +01:00
Uwe Kleine-König 9274307146 firmware: arm_ffa: Ensure drivers provide a probe function
The bus probe callback calls the driver callback without further
checking. Better be safe than sorry and refuse registration of a driver
without a probe function to prevent a NULL pointer exception.

Link: https://lore.kernel.org/r/20210621201652.127611-1-u.kleine-koenig@pengutronix.de
Fixes: e781858488 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-07-12 14:20:06 +01:00
Sudeep Holla cc2195fe53 firmware: arm_ffa: Add support for MEM_* interfaces
Most of the MEM_* APIs share the same parameters, so they can be
generalised. Currently only MEM_SHARE is implemented and the user space
interface for that is not added yet.

Link: https://lore.kernel.org/r/20210521151033.181846-6-sudeep.holla@arm.com
Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-05-26 22:38:43 +01:00
Sudeep Holla d0c0bce831 firmware: arm_ffa: Setup in-kernel users of FFA partitions
Parse the FFA nodes from the device-tree and register all the partitions
whose services will be used in the kernel.

In order to also enable in-kernel users of FFA interface, let us add
simple set of operations for such devices.

The in-kernel users are registered without the character device interface.

Link: https://lore.kernel.org/r/20210521151033.181846-5-sudeep.holla@arm.com
Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-05-26 22:38:43 +01:00
Sudeep Holla 714be77e97 firmware: arm_ffa: Add support for SMCCC as transport to FFA driver
There are requests to keep the transport separate in order to allow
other possible transports like virtio. So let us keep the SMCCC transport
specific routines abstracted.

It is kept simple for now. Once we add another transport, we can develop
better abstraction.

Link: https://lore.kernel.org/r/20210521151033.181846-4-sudeep.holla@arm.com
Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-05-26 22:36:46 +01:00
Sudeep Holla 3bbfe98710 firmware: arm_ffa: Add initial Arm FFA driver support
This just add a basic driver that sets up the transport(e.g. SMCCC),
checks the FFA version implemented, get the partition ID for self and
sets up the Tx/Rx buffers for communication.

Link: https://lore.kernel.org/r/20210521151033.181846-3-sudeep.holla@arm.com
Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-05-26 22:36:46 +01:00
Sudeep Holla e781858488 firmware: arm_ffa: Add initial FFA bus support for device enumeration
The Arm FF for Armv8-A specification has concept of endpoints or
partitions. In the Normal world, a partition could be a VM when
the Virtualization extension is enabled or the kernel itself.

In order to handle multiple partitions, we can create a FFA device for
each such partition on a dedicated FFA bus. Similarly, different drivers
requiring FFA transport can be registered on the same bus. We can match
the device and drivers using UUID. This is mostly for the in-kernel
users with FFA drivers.

Link: https://lore.kernel.org/r/20210521151033.181846-2-sudeep.holla@arm.com
Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2021-05-26 22:36:46 +01:00