firmware: arm_ffa: Make ffa_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the ffa_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 <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20240211-bus_cleanup-firmware2-v1-1-1851c92c7be7@marliere.net
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Declare ffa_bus_type structure in the header

smatch reports:
drivers/firmware/arm_ffa/bus.c:108:17: warning:
symbol 'ffa_bus_type' was not declared. Should it be static?

ffa_bus_type is exported to be useful in the FF-A driver. So this
warning is not correct. However, declaring the ffa_bus_type structure
in the header like many other bus_types do already removes this warning.
So let us just do the same and get rid of the warning.

Link: https://lore.kernel.org/r/20231024105715.2369638-1-sudeep.holla@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Update memory descriptor to support v1.1 format

Update memory transaction descriptor structure to accommodate couple of
new entries in v1.1 which were previously marked reserved and MBZ(must
be zero).

It also removes the flexible array member ep_mem_access in the memory
transaction descriptor structure as it need not be at fixed offset.
Also update ffa_mem_desc_offset() accessor to handle both old and new
formats of memory transaction descriptors.

The updated ffa_mem_region structure aligns with new format in v1.1 and
hence the driver/user must take care not to use members beyond and
including ep_mem_offset when using the old format.

Link: https://lore.kernel.org/r/20231005-ffa_v1-1_notif-v4-16-cddd3237809c@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

KVM: arm64: FFA: Remove access of endpoint memory access descriptor array

FF-A v1.1 removes the fixed location of endpoint memory access descriptor
array within the memory transaction descriptor structure. In preparation
to remove the ep_mem_access member from the ffa_mem_region structure,
provide the accessor to fetch the offset and use the same in FF-A proxy
implementation.

The accessor take the FF-A version as the argument from which the memory
access descriptor format can be determined. v1.0 uses the old format while
v1.1 onwards use the new format specified in the v1.1 specification.

Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Will Deacon <will@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231005-ffa_v1-1_notif-v4-14-cddd3237809c@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Simplify the computation of transmit and fragment length

The computation of endpoint memory access descriptor's composite memory
region descriptor offset is using COMPOSITE_CONSTITUENTS_OFFSET which is
unnecessary complicated. Composite memory region descriptor always follow
the endpoint memory access descriptor array and hence it is computed
accordingly. COMPOSITE_CONSTITUENTS_OFFSET is useless and wrong for any
input other than endpoint memory access descriptor count.

Let us drop the usage of COMPOSITE_CONSTITUENTS_OFFSET to simplify the
computation of total transmit and fragment length in the memory
transactions.

Link: https://lore.kernel.org/r/20231005-ffa_v1-1_notif-v4-13-cddd3237809c@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Add interface to send a notification to a given partition

The framework provides an interface to the sender endpoint to specify
the notification to signal to the receiver endpoint. A sender signals
a notification by requesting its partition manager to set the
corresponding bit in the notifications bitmap of the receiver.

Expose the ability to send a notification to another partition.

Link: https://lore.kernel.org/r/20231005-ffa_v1-1_notif-v4-11-cddd3237809c@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Add interfaces to request notification callbacks

Add interface to the FFA driver to allow for client drivers to request
and relinquish a notification as well as provide a callback for the
notification.

Link: https://lore.kernel.org/r/20231005-ffa_v1-1_notif-v4-10-cddd3237809c@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Add schedule receiver callback mechanism

Enable client drivers to register a callback function that will be
called when one or more notifications are pending for a target
partition as part of schedule receiver interrupt handling.

Link: https://lore.kernel.org/r/20231005-ffa_v1-1_notif-v4-9-cddd3237809c@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Implement the FFA_RUN interface

FFA_RUN is used by a scheduler to allocate CPU cycles to a target
endpoint execution context specified in the target information parameter.

If the endpoint execution context is in the waiting/blocked state, it
transitions to the running state.

Expose the ability to call FFA_RUN in order to give any partition in the
system cpu cycles to perform IMPDEF functionality.

Link: https://lore.kernel.org/r/20231005-ffa_v1-1_notif-v4-4-cddd3237809c@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Update the FF-A command list with v1.1 additions

Arm Firmware Framework for A-profile(FFA) v1.1 introduces notifications
and indirect messaging based upon notifications support and extends some
of the memory interfaces.

Let us add all the newly supported FF-A function IDs in the spec.
Also update to the error values and associated handling.

Link: https://lore.kernel.org/r/20231005-ffa_v1-1_notif-v4-1-cddd3237809c@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

KVM: arm64: Handle FFA_RXTX_MAP and FFA_RXTX_UNMAP calls from the host

Handle FFA_RXTX_MAP and FFA_RXTX_UNMAP calls from the host by sharing
the host's mailbox memory with the hypervisor and establishing a
separate pair of mailboxes between the hypervisor and the SPMD at EL3.

Co-developed-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230523101828.7328-5-will@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

firmware: arm_ffa: Fix FFA device names for logical partitions

Each physical partition can provide multiple services each with UUID.
Each such service can be presented as logical partition with a unique
combination of VM ID and UUID. The number of distinct UUID in a system
will be less than or equal to the number of logical partitions.

However, currently it fails to register more than one logical partition
or service within a physical partition as the device name contains only
VM ID while both VM ID and UUID are maintained in the partition information.
The kernel complains with the below message:

| sysfs: cannot create duplicate filename '/devices/arm-ffa-8001'
| CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.3.0-rc7 #8
| Hardware name: FVP Base RevC (DT)
| Call trace:
| dump_backtrace+0xf8/0x118
| show_stack+0x18/0x24
| dump_stack_lvl+0x50/0x68
| dump_stack+0x18/0x24
| sysfs_create_dir_ns+0xe0/0x13c
| kobject_add_internal+0x220/0x3d4
| kobject_add+0x94/0x100
| device_add+0x144/0x5d8
| device_register+0x20/0x30
| ffa_device_register+0x88/0xd8
| ffa_setup_partitions+0x108/0x1b8
| ffa_init+0x2ec/0x3a4
| do_one_initcall+0xcc/0x240
| do_initcall_level+0x8c/0xac
| do_initcalls+0x54/0x94
| do_basic_setup+0x1c/0x28
| kernel_init_freeable+0x100/0x16c
| kernel_init+0x20/0x1a0
| ret_from_fork+0x10/0x20
| kobject_add_internal failed for arm-ffa-8001 with -EEXIST, don't try to
| register things with the same name in the same directory.
| arm_ffa arm-ffa: unable to register device arm-ffa-8001 err=-17
| ARM FF-A: ffa_setup_partitions: failed to register partition ID 0x8001

By virtue of being random enough to avoid collisions when generated in a
distributed system, there is no way to compress UUID keys to the number
of bits required to identify each. We can eliminate '-' in the name but
it is not worth eliminating 4 bytes and add unnecessary logic for doing
that. Also v1.0 doesn't provide the UUID of the partitions which makes
it hard to use the same for the device name.

So to keep it simple, let us alloc an ID using ida_alloc() and append the
same to "arm-ffa" to make up a unique device name. Also stash the id value
in ffa_dev to help freeing the ID later when the device is destroyed.

Fixes: e781858488b9 ("firmware: arm_ffa: Add initial FFA bus support for device enumeration")
Reported-by: Lucian Paul-Trifu <lucian.paul-trifu@arm.com>
Link: https://lore.kernel.org/r/20230419-ffa_fixes_6-4-v2-3-d9108e43a176@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Move comment before the field it is documenting

This is consistent with the other comments in the struct.

Co-developed-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20221116170335.2341003-3-qperret@google.com
Signed-off-by: Will Deacon <will@kernel.org>

firmware: arm_ffa: Move constants to header file

FF-A function IDs and error codes will be needed in the hypervisor too,
so move to them to the header file where they can be shared. Rename the
version constants with an "FFA_" prefix so that they are less likely
to clash with other code in the tree.

Co-developed-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Andrew Walbran <qwandor@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20221116170335.2341003-2-qperret@google.com
Signed-off-by: Will Deacon <will@kernel.org>

firmware: arm_ffa: Split up ffa_ops into info, message and memory operations

In preparation to make memory operations accessible for a non
ffa_driver/device, it is better to split the ffa_ops into different
categories of operations: info, message and memory. The info and memory
are ffa_device independent and can be used without any associated
ffa_device from a non ffa_driver.

However, we don't export these info and memory APIs yet without the user.
The first users of these APIs can export them.

Link: https://lore.kernel.org/r/20220907145240.1683088-11-sudeep.holla@arm.com
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Set up 32bit execution mode flag using partiion property

FF-A v1.1 adds a flag in the partition properties to indicate if the
partition runs in the AArch32 or AArch64 execution state. Use the same
to set-up the 32-bit execution flag mode in the ffa_dev automatically
if the detected firmware version is above v1.0 and ignore any requests
to do the same from the ffa_driver.

Link: https://lore.kernel.org/r/20220907145240.1683088-10-sudeep.holla@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Add v1.1 get_partition_info support

FF-A v1.1 adds support to discovery the UUIDs of the partitions that was
missing in v1.0 and which the driver workarounds by using UUIDs supplied
by the ffa_drivers.

Add the v1.1 get_partition_info support and disable the workaround if
the detected FF-A version is greater than v1.0.

Link: https://lore.kernel.org/r/20220907145240.1683088-9-sudeep.holla@arm.com
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Rename ffa_dev_ops as ffa_ops

Except the message APIs, all other APIs are ffa_device independent and can
be used without any associated ffa_device from a non ffa_driver.

In order to reflect the same, just rename ffa_dev_ops as ffa_ops to
avoid any confusion or to keep it simple.

Link: https://lore.kernel.org/r/20220907145240.1683088-8-sudeep.holla@arm.com
Suggested-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Make memory apis ffa_device independent

There is a requirement to make memory APIs independent of the ffa_device.
One of the use-case is to have a common memory driver that manages the
memory for all the ffa_devices. That common memory driver won't be a
ffa_driver or won't have any ffa_device associated with it. So having
these memory APIs accessible without a ffa_device is needed and should
be possible as most of these are handled by the partition manager(SPM
or hypervisor).

Drop the ffa_device argument to the memory APIs and make them ffa_device
independent.

Link: https://lore.kernel.org/r/20220907145240.1683088-7-sudeep.holla@arm.com
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Remove ffa_dev_ops_get()

The only user of this exported ffa_dev_ops_get() was OPTEE driver which
now uses ffa_dev->ops directly, there are no other users for this.

Also, since any ffa driver can use ffa_dev->ops directly, there will be
no need for ffa_dev_ops_get(), so just remove ffa_dev_ops_get().

Link: https://lore.kernel.org/r/20220907145240.1683088-4-sudeep.holla@arm.com
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Add pointer to the ffa_dev_ops in struct ffa_dev

Currently ffa_dev_ops_get() is the way to fetch the ffa_dev_ops pointer.
It checks if the ffa_dev structure pointer is valid before returning the
ffa_dev_ops pointer.

Instead, the pointer can be made part of the ffa_dev structure and since
the core driver is incharge of creating ffa_device for each identified
partition, there is no need to check for the validity explicitly if the
pointer is embedded in the structure.

Add the pointer to the ffa_dev_ops in the ffa_dev structure itself and
initialise the same as part of creation of the device.

Link: https://lore.kernel.org/r/20220907145240.1683088-2-sudeep.holla@arm.com
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

firmware: arm_ffa: Add ffa_dev_get_drvdata helper function

Add a helper function to fetch ffa_dev's driver_data using
dev_get_drvdata. At the same time move existing ffa_dev_set_drvdata
to use dev_set_drvdata.

Link: https://lore.kernel.org/r/20220429113946.2087145-3-sudeep.holla@arm.com
Suggested-by: Arunachalam Ganapathy <arunachalam.ganapathy@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

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>

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>

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>

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>