Copying from a 144 byte structure arm_smccc_1_2_regs at an offset of 32
into an 112 byte struct ffa_send_direct_data2 causes a compile-time warning:

 | In file included from drivers/firmware/arm_ffa/driver.c:25:
 | In function 'fortify_memcpy_chk',
 |    inlined from 'ffa_msg_send_direct_req2' at drivers/firmware/arm_ffa/driver.c:504:3:
 | include/linux/fortify-string.h:580:4: warning: call to '__read_overflow2_field'
 | 	declared with 'warning' attribute: detected read beyond size of field
 | 	(2nd parameter); maybe use struct_group()? [-Wattribute-warning]
 |                         __read_overflow2_field(q_size_field, size);

Fix it by not passing a plain buffer to memcpy() to avoid the overflow
warning.

Fixes: aaef3bc98129 ("firmware: arm_ffa: Add support for FFA_MSG_SEND_DIRECT_{REQ,RESP}2")
Signed-off-by: Gavin Shan <gshan@redhat.com>
Message-Id: <20241014004724.991353-1-gshan@redhat.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Copying to a 16 byte structure into an 8-byte struct member
causes a compile-time warning:

 | In file included from drivers/firmware/arm_ffa/driver.c:25:
 | In function 'fortify_memcpy_chk',
 |    inlined from 'export_uuid' at include/linux/uuid.h:88:2,
 |    inlined from 'ffa_msg_send_direct_req2' at drivers/firmware/arm_ffa/driver.c:488:2:
 | include/linux/fortify-string.h:571:25: error: call to '__write_overflow_field'
 |   declared with attribute warning: detected write beyond size of field
 |   (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
 |                         __write_overflow_field(p_size_field, size);

Use a union for the conversion instead and make sure the byte order
is fixed in the process.

Fixes: aaef3bc98129 ("firmware: arm_ffa: Add support for FFA_MSG_SEND_DIRECT_{REQ,RESP}2")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Message-Id: <20240909110938.247976-1-arnd@kernel.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

An endpoint can discover the minimum size, maximum size and alignment
boundary for the Rx/Tx buffers by passing the function ID of the
FFA_RXTX_MAP ABI as input in the FFA_FEATURES interface. The maximum
size is an optional field and a value of 0 means that the partition
manager or the hypervisor does not enforce a maximum size.

Use the discovery mechanism and remove the hardcoded 4kB buffer size.
If the discovery fails, it still defaults to 4kB.

Message-Id: <20240820-ffa_v1-2-v2-7-18c0c5f3c65e@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Successful completion of both direct messaging function can be indicated
through an invocation of FFA_YIELD or GGA_INTERRUPT by the callee.

FFA_INTERRUPT indicates that the direct request was interrupted and must
be resumed through the FFA_RUN interface which is already done in the
driver.

FFA_YIELD indicates that the receiver endpoint has transitioned to the
blocked runtime state and must be resumed through the FFA_RUN interface.
However, the way receiver endpoint gets unblocked is implementation
defined. So, the driver just sleeps for 1 - 2ms and issues FFA_RUN. It
can return to the caller with FFA_YIELD is the receiver endpoint is still
blocked.

Message-Id: <20240820-ffa_v1-2-v2-6-18c0c5f3c65e@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

FFA_MSG_SEND_DIRECT_{REQ,RESP} supported only x3-x7 to pass implementation
defined values as part of the message. This may not be sufficient sometimes
and also it would be good to use all the registers supported by SMCCC v1.2
(x0-x17) for such register based communication.

Also another limitation with the FFA_MSG_SEND_DIRECT_{REQ,RESP} is the
ability to target a specific service within the partition based on it's
UUID.

In order to address both of the above limitation, FF-A v1.2 introduced
FFA_MSG_SEND_DIRECT_{REQ,RESP}2 which has the ability to target the
message to a specific service based on its UUID within a partition as
well as utilise all the available registers(x4-x17 specifically) for
the communication.

This change adds support for FFA_MSG_SEND_DIRECT_REQ2 and
FFA_MSG_SEND_DIRECT_RESP2.

Message-Id: <20240820-ffa_v1-2-v2-5-18c0c5f3c65e@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

FF-A v1.2 introduced FFA_PARTITION_INFO_GET_REGS which is similar to
FFA_PARTITION_INFO_GET except that the former uses the registers to
get the required information instead of the Rx buffer which the latter
uses.

We need to first check if the platform supports this new API using
FFA_FEATURES so that we can fallback to the FFA_PARTITION_INFO_GET
(which is mandatory) if FFA_PARTITION_INFO_GET_REGS is not implemented.

Message-Id: <20240820-ffa_v1-2-v2-4-18c0c5f3c65e@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

We need to use ffa_features() in ffa_partition_probe() to detect if
the newer FFA_PARTITION_INFO_GET_REGS API is supported in the platform
or not. To avoid unnecessary forward declaration within the file, let
us just move this ffa_features() earlier.

No funtional change.

Message-Id: <20240820-ffa_v1-2-v2-3-18c0c5f3c65e@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Arm Firmware Framework for A-profile(FFA) v1.2 introduces register based
discovery mechanism and direct messaging extensions that enables to target
specific UUID within a partition.

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

Message-Id: <20240820-ffa_v1-2-v2-2-18c0c5f3c65e@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

These changes fixes a set of below coding style issues:
1. spaces required around that '=' (ctx:VxW)
2. possible unnecessary 'out of memory' message
3. unnecessary for single statement blocks

Message-Id: <20240820-ffa_v1-2-v2-1-18c0c5f3c65e@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

Pull driver core updates from Greg KH:
 "Here is the big set of driver core changes for 6.11-rc1.

  Lots of stuff in here, with not a huge diffstat, but apis are evolving
  which required lots of files to be touched. Highlights of the changes
  in here are:

   - platform remove callback api final fixups (Uwe took many releases
     to get here, finally!)

   - Rust bindings for basic firmware apis and initial driver-core
     interactions.

     It's not all that useful for a "write a whole driver in rust" type
     of thing, but the firmware bindings do help out the phy rust
     drivers, and the driver core bindings give a solid base on which
     others can start their work.

     There is still a long way to go here before we have a multitude of
     rust drivers being added, but it's a great first step.

   - driver core const api changes.

     This reached across all bus types, and there are some fix-ups for
     some not-common bus types that linux-next and 0-day testing shook
     out.

     This work is being done to help make the rust bindings more safe,
     as well as the C code, moving toward the end-goal of allowing us to
     put driver structures into read-only memory. We aren't there yet,
     but are getting closer.

   - minor devres cleanups and fixes found by code inspection

   - arch_topology minor changes

   - other minor driver core cleanups

  All of these have been in linux-next for a very long time with no
  reported problems"

* tag 'driver-core-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (55 commits)
  ARM: sa1100: make match function take a const pointer
  sysfs/cpu: Make crash_hotplug attribute world-readable
  dio: Have dio_bus_match() callback take a const *
  zorro: make match function take a const pointer
  driver core: module: make module_[add|remove]_driver take a const *
  driver core: make driver_find_device() take a const *
  driver core: make driver_[create|remove]_file take a const *
  firmware_loader: fix soundness issue in `request_internal`
  firmware_loader: annotate doctests as `no_run`
  devres: Correct code style for functions that return a pointer type
  devres: Initialize an uninitialized struct member
  devres: Fix memory leakage caused by driver API devm_free_percpu()
  devres: Fix devm_krealloc() wasting memory
  driver core: platform: Switch to use kmemdup_array()
  driver core: have match() callback in struct bus_type take a const *
  MAINTAINERS: add Rust device abstractions to DRIVER CORE
  device: rust: improve safety comments
  MAINTAINERS: add Danilo as FIRMWARE LOADER maintainer
  MAINTAINERS: add Rust FW abstractions to FIRMWARE LOADER
  firmware: rust: improve safety comments
  ...