Commit 318a197182 (device property: refactor built-in properties
support) went way too far and brought a union aliasing. Partially
revert it here to get rid of union aliasing.
Note, all Apple properties are considered as u8 arrays. To get a value
of any of them the caller must use device_property_read_u8_array().
What's union aliasing?
~~~~~~~~~~~~~~~~~~~~~~
The C99 standard in section 6.2.5 paragraph 20 defines union type as
"an overlapping nonempty set of member objects". It also states in
section 6.7.2.1 paragraph 14 that "the value of at most one of the
members can be stored in a union object at any time'.
Union aliasing is a type punning mechanism using union members to store
as one type and read back as another.
Why it's not good?
~~~~~~~~~~~~~~~~~~
Section 6.2.6.1 paragraph 6 says that a union object may not be a trap
representation, although its member objects may be.
Meanwhile annex J.1 says that "the value of a union member other than
the last one stored into" is unspecified [removed in C11].
In TC3, a footnote is added which specifies that accessing a member of a
union other than the last one stored causes "the object representation"
to be re-interpreted in the new type and specifically refers to this as
"type punning". This conflicts to some degree with Annex J.1.
While it's working in Linux with GCC, the use of union members to do
type punning is not clear area in the C standard and might lead to
unspecified behaviour.
More information is available in this [1] blog post.
[1]: https://davmac.wordpress.com/2010/02/26/c99-revisited/
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull driver core updates from Greg KH:
"Here is the set of "big" driver core patches for 4.16-rc1.
The majority of the work here is in the firmware subsystem, with
reworks to try to attempt to make the code easier to handle in the
long run, but no functional change. There's also some tree-wide sysfs
attribute fixups with lots of acks from the various subsystem
maintainers, as well as a handful of other normal fixes and changes.
And finally, some license cleanups for the driver core and sysfs code.
All have been in linux-next for a while with no reported issues"
* tag 'driver-core-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (48 commits)
device property: Define type of PROPERTY_ENRTY_*() macros
device property: Reuse property_entry_free_data()
device property: Move property_entry_free_data() upper
firmware: Fix up docs referring to FIRMWARE_IN_KERNEL
firmware: Drop FIRMWARE_IN_KERNEL Kconfig option
USB: serial: keyspan: Drop firmware Kconfig options
sysfs: remove DEBUG defines
sysfs: use SPDX identifiers
drivers: base: add coredump driver ops
sysfs: add attribute specification for /sysfs/devices/.../coredump
test_firmware: fix missing unlock on error in config_num_requests_store()
test_firmware: make local symbol test_fw_config static
sysfs: turn WARN() into pr_warn()
firmware: Fix a typo in fallback-mechanisms.rst
treewide: Use DEVICE_ATTR_WO
treewide: Use DEVICE_ATTR_RO
treewide: Use DEVICE_ATTR_RW
sysfs.h: Use octal permissions
component: add debugfs support
bus: simple-pm-bus: convert bool SIMPLE_PM_BUS to tristate
...
Pull networking updates from David Miller:
1) Significantly shrink the core networking routing structures. Result
of http://vger.kernel.org/~davem/seoul2017_netdev_keynote.pdf
2) Add netdevsim driver for testing various offloads, from Jakub
Kicinski.
3) Support cross-chip FDB operations in DSA, from Vivien Didelot.
4) Add a 2nd listener hash table for TCP, similar to what was done for
UDP. From Martin KaFai Lau.
5) Add eBPF based queue selection to tun, from Jason Wang.
6) Lockless qdisc support, from John Fastabend.
7) SCTP stream interleave support, from Xin Long.
8) Smoother TCP receive autotuning, from Eric Dumazet.
9) Lots of erspan tunneling enhancements, from William Tu.
10) Add true function call support to BPF, from Alexei Starovoitov.
11) Add explicit support for GRO HW offloading, from Michael Chan.
12) Support extack generation in more netlink subsystems. From Alexander
Aring, Quentin Monnet, and Jakub Kicinski.
13) Add 1000BaseX, flow control, and EEE support to mvneta driver. From
Russell King.
14) Add flow table abstraction to netfilter, from Pablo Neira Ayuso.
15) Many improvements and simplifications to the NFP driver bpf JIT,
from Jakub Kicinski.
16) Support for ipv6 non-equal cost multipath routing, from Ido
Schimmel.
17) Add resource abstration to devlink, from Arkadi Sharshevsky.
18) Packet scheduler classifier shared filter block support, from Jiri
Pirko.
19) Avoid locking in act_csum, from Davide Caratti.
20) devinet_ioctl() simplifications from Al viro.
21) More TCP bpf improvements from Lawrence Brakmo.
22) Add support for onlink ipv6 route flag, similar to ipv4, from David
Ahern.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1925 commits)
tls: Add support for encryption using async offload accelerator
ip6mr: fix stale iterator
net/sched: kconfig: Remove blank help texts
openvswitch: meter: Use 64-bit arithmetic instead of 32-bit
tcp_nv: fix potential integer overflow in tcpnv_acked
r8169: fix RTL8168EP take too long to complete driver initialization.
qmi_wwan: Add support for Quectel EP06
rtnetlink: enable IFLA_IF_NETNSID for RTM_NEWLINK
ipmr: Fix ptrdiff_t print formatting
ibmvnic: Wait for device response when changing MAC
qlcnic: fix deadlock bug
tcp: release sk_frag.page in tcp_disconnect
ipv4: Get the address of interface correctly.
net_sched: gen_estimator: fix lockdep splat
net: macb: Handle HRESP error
net/mlx5e: IPoIB, Fix copy-paste bug in flow steering refactoring
ipv6: addrconf: break critical section in addrconf_verify_rtnl()
ipv6: change route cache aging logic
i40e/i40evf: Update DESC_NEEDED value to reflect larger value
bnxt_en: cleanup DIM work on device shutdown
...
Some of the drivers may use the macro at runtime flow, like
struct property_entry p[10];
...
p[index++] = PROPERTY_ENTRY_U8("u8 property", u8_data);
In that case and absence of the data type compiler fails the build:
drivers/char/ipmi/ipmi_dmi.c:79:29: error: Expected ; at end of statement
drivers/char/ipmi/ipmi_dmi.c:79:29: error: got {
Acked-by: Corey Minyard <cminyard@mvista.com>
Cc: Corey Minyard <minyard@acm.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Implement a new helper function fwnode_get_next_available_child_node(),
which enables obtaining next enabled child fwnode, which
works on a similar basis to OF's of_get_next_available_child().
This commit also introduces a macro, thanks to which it is
possible to iterate over the available fwnodes, using the
new function described above.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Until now there were two very similar functions allowing
to get Linux IRQ number from ACPI handle (acpi_irq_get())
and OF node (of_irq_get()). The first one appeared to be used
only as a subroutine of platform_irq_get(), which (in the generic
code) limited IRQ obtaining from _CRS method only to nodes
associated to kernel's struct platform_device.
This patch introduces a new helper routine - fwnode_irq_get(),
which allows to get the IRQ number directly from the fwnode
to be used as common for OF/ACPI worlds. It is usable not
only for the parents fwnodes, but also for the child nodes
comprising their own _CRS methods with interrupts description.
In order to be able o satisfy compilation with !CONFIG_ACPI
and also simplify the new code, introduce a helper macro
(ACPI_HANDLE_FWNODE), with which it is possible to reach
an ACPI handle directly from its fwnode.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Until now there were two almost identical functions for
obtaining network PHY mode - of_get_phy_mode() and,
more generic, device_get_phy_mode(). However it is not uncommon,
that the network interface is represented as a child
of the actual controller, hence it is not associated
directly to any struct device, required by the latter
routine.
This commit allows for getting the PHY mode for
children nodes in the ACPI world by introducing a new function -
fwnode_get_phy_mode(). This commit also changes
device_get_phy_mode() routine to be its wrapper, in order
to prevent unnecessary duplication.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Until now there were two almost identical functions for
obtaining MAC address - of_get_mac_address() and, more generic,
device_get_mac_address(). However it is not uncommon,
that the network interface is represented as a child
of the actual controller, hence it is not associated
directly to any struct device, required by the latter
routine.
This commit allows for getting the MAC address for
children nodes in the ACPI world by introducing a new function -
fwnode_get_mac_address(). This commit also changes
device_get_mac_address() routine to be its wrapper, in order
to prevent unnecessary duplication.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is an OF/ACPI function to obtain the driver data. We want to hide
OF/ACPI details from the device drivers and abstract following the device
family of functions.
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Add a convenience macro for iterating over graph endpoints. Iterating over
graph endpoints using fwnode_graph_get_next_endpoint() is a recurring
pattern, and this macro allows calling that function in a slightly more
convenient way. For instance,
for (child = NULL;
(child = fwnode_graph_get_next_endpoint(fwnode, child)); )
becomes
fwnode_graph_for_each_endpoint(fwnode, child)
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The fwnode_handle_get() function is used to obtain a reference to an
fwnode. A common usage pattern for the OF equivalent of the function is:
mynode = of_node_get(node);
Similarly make fwnode_handle_get() return the fwnode to which the
reference was obtained.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The new fwnode_property_get_reference_args() interface amends the fwnode
property API with the functionality of both of_parse_phandle_with_args()
and __acpi_node_get_property_reference().
The semantics is slightly different: the cells property is ignored on ACPI
as the number of arguments can be explicitly obtained from the firmware
interface.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Similar to OF endpoints, endpoint type nodes can be also supported on
ACPI. In order to make it possible for drivers to ignore the matter,
add a type for fwnode_endpoint and a function to parse them.
On ACPI, find the child node index instead of relying on the "endpoint"
property.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The function to obtain a fwnode related to a struct device is useful for
drivers that use the fwnode property API: it allows not being aware of the
underlying firmware implementation.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
fwnode_handle_get() is used to obtain a reference to a fwnode_handle
container. In this case this is OF specific struct device_node.
This complements fwnode_handle_put() which is already implemented.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This follows DT implementation of of_graph_* APIs but we call them
fwnode_graph_* instead. For DT nodes the existing of_graph_* implementation
will be used. For ACPI we use the new ACPI graph implementation instead.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Since now we have means to enumerate all children of any fwnode even in
ACPI we can implement fwnode_get_named_child_node(). This is similar than
device_get_named_child_node() with the exception that it can be called to
any fwnode handle. Make device_get_named_child_node() call directly this
new function.
This is useful in cases where we need to be able to find child nodes which
are not direct descendants of the parent device.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The ACPI _DSD hierarchical data extension makes it possible to have
hierarchies deeper than one level in similar way than DT allows. These
"subsubnodes" have not been accessible because device property
implementation only provides device_get_next_child_node() that is limited
to direct descendants of a device.
We need this ability in order support things like remote endpoints
currently supported in DT with of_graph_* APIs.
Modify acpi_get_next_subnode() to accept fwnode handle instead and update
callers accordingly. Also add a new function fwnode_get_next_child_node()
that works directly with fwnodes and modify device_get_next_child_node() to
call it directly. While there add a macro fwnode_for_each_child_node()
analogous to the current device_for_each_child_node() but it works with
fwnodes instead of devices.
Link: http://www.uefi.org/sites/default/files/resources/_DSD-hierarchical-data-extension-UUID-v1.pdf
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Now that ACPI has support for returning parent firmware node for both types
of nodes we can expose this to others as well. This adds a new function
fwnode_get_parent() that can be used for DT and ACPI nodes to retrieve the
parent firmware node.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
