ptp: annotate data-race around q->head and q->tail

As I was working on a syzbot report, I found that KCSAN would
probably complain that reading q->head or q->tail without
barriers could lead to invalid results.

Add corresponding READ_ONCE() and WRITE_ONCE() to avoid
load-store tearing.

Fixes: d94ba80ebbea ("ptp: Added a brand new class driver for ptp clocks.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Link: https://lore.kernel.org/r/20231109174859.3995880-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Revert "ptp: Fixes a null pointer dereference in ptp_ioctl"

This reverts commit 8a4f030dbced6fc255cbe67b2d0a129947e18493.

Richard says:

The test itself is harmless, but keeping it will make people think,
"oh this pointer can be invalid."

In fact the core stack ensures that ioctl() can't be invoked after
release(), otherwise Bad Stuff happens.

Fixes: 8a4f030dbced ("ptp: Fixes a null pointer dereference in ptp_ioctl")
Link: https://lore.kernel.org/all/ZVAf_qdRfDAQYUt-@hoboy.vegasvil.org/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

ptp: Fixes a null pointer dereference in ptp_ioctl

Syzkaller found a null pointer dereference in ptp_ioctl
originating from the lack of a null check for tsevq.

```
general protection fault, probably for non-canonical
address 0xdffffc000000020b: 0000 [#1] PREEMPT SMP KASAN
KASAN: probably user-memory-access in range
[0x0000000000001058-0x000000000000105f]
CPU: 0 PID: 5053 Comm: syz-executor353 Not tainted
6.6.0-syzkaller-10396-g4652b8e4f3ff #0
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 10/09/2023
RIP: 0010:ptp_ioctl+0xcb7/0x1d10 drivers/ptp/ptp_chardev.c:476
...
Call Trace:
<TASK>
posix_clock_ioctl+0xf8/0x160 kernel/time/posix-clock.c:86
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:871 [inline]
__se_sys_ioctl fs/ioctl.c:857 [inline]
__x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
```

This patch fixes the issue by adding a check for tsevq and
ensuring ptp_ioctl returns with an error if tsevq is null.

Reported-by: syzbot+8a78ecea7ac1a2ea26e5@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=8a78ecea7ac1a2ea26e5
Fixes: c5a445b1e934 ("ptp: support event queue reader channel masks")
Signed-off-by: Yuran Pereira <yuran.pereira@hotmail.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: fix corrupted list in ptp_open

There is no lock protection when writing ptp->tsevqs in ptp_open() and
ptp_release(), which can cause data corruption, use spin lock to avoid this
issue.

Moreover, ptp_release() should not be used to release the queue in ptp_read(),
and it should be deleted altogether.

Acked-by: Richard Cochran <richardcochran@gmail.com>
Reported-and-tested-by: syzbot+df3f3ef31f60781fa911@syzkaller.appspotmail.com
Fixes: 8f5de6fb2453 ("ptp: support multiple timestamp event readers")
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Link: https://lore.kernel.org/r/tencent_CD19564FFE8DA8A5918DFE92325D92DD8107@qq.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

ptp: ptp_read should not release queue

Firstly, queue is not the memory allocated in ptp_read;
Secondly, other processes may block at ptp_read and wait for conditions to be
met to perform read operations.

Acked-by: Richard Cochran <richardcochran@gmail.com>
Reported-and-tested-by: syzbot+df3f3ef31f60781fa911@syzkaller.appspotmail.com
Fixes: 8f5de6fb2453 ("ptp: support multiple timestamp event readers")
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Link: https://lore.kernel.org/r/tencent_18747D76F1675A3C633772960237544AAA09@qq.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

ptp: add debugfs interface to see applied channel masks

Use debugfs to be able to view channel mask applied to every timestamp
event queue.

Every time the device is opened, a new entry is created in
`$DEBUGFS_MOUNTPOINT/ptpN/$INSTANCE_ADDRESS/mask`.

The mask value can be viewed grouped in 32bit decimal values using cat,
or converted to hexadecimal with the included `ptpchmaskfmt.sh` script.
32 bit values are listed from least significant to most significant.

Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: support event queue reader channel masks

On systems with multiple timestamp event channels, some readers might
want to receive only a subset of those channels.

Add the necessary modifications to support timestamp event channel
filtering, including two IOCTL operations:

- Clear all channels
- Enable one channel

The mask modification operations will be applied exclusively on the
event queue assigned to the file descriptor used on the IOCTL operation,
so the typical procedure to have a reader receiving only a subset of the
enabled channels would be:

- Open device file
- ioctl: clear all channels
- ioctl: enable one channel
- start reading

Calling the enable one channel ioctl more than once will result in
multiple enabled channels.

Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: support multiple timestamp event readers

Use linked lists to create one event queue per open file. This enables
simultaneous readers for timestamp event queues.

Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: Replace timestamp event queue with linked list

Introduce linked lists to access the timestamp event queue.

Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

posix-clock: introduce posix_clock_context concept

Add the necessary structure to support custom private-data per
posix-clock user.

The previous implementation of posix-clock assumed all file open
instances need access to the same clock structure on private_data.

The need for individual data structures per file open instance has been
identified when developing support for multiple timestamp event queue
users for ptp_clock.

Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: Add .getmaxphase callback to ptp_clock_info

Enables advertisement of the maximum offset supported by the phase control
functionality of PHCs. The callback is used to return an error if an offset
not supported by the PHC is used in ADJ_OFFSET. The ioctls
PTP_CLOCK_GETCAPS and PTP_CLOCK_GETCAPS2 now advertise the maximum offset a
PHC's phase control functionality is capable of supporting. Introduce new
sysfs node, max_phase_adjustment.

Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Maciek Machnikowski <maciek@machnikowski.net>
Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: only allow phase values lower than 1 period

The way we define the phase (the difference between the time of the
signal's rising edge, and the closest integer multiple of the period),
it doesn't make sense to have a phase value equal or larger than 1
period.

So deny these settings coming from the user.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: add ability to configure duty cycle for periodic output

There are external event timestampers (PHCs with support for
PTP_EXTTS_REQUEST) that timestamp both event edges.

When those edges are very close (such as in the case of a short pulse),
there is a chance that the collected timestamp might be of the rising,
or of the falling edge, we never know.

There are also PHCs capable of generating periodic output with a
configurable duty cycle. This is good news, because we can space the
rising and falling edge out enough in time, that the risks to overrun
the 1-entry timestamp FIFO of the extts PHC are lower (example: the
perout PHC can be configured for a period of 1 second, and an "on" time
of 0.5 seconds, resulting in a duty cycle of 50%).

A flag is introduced for signaling that an on time is present in the
perout request structure, for preserving compatibility. Logically
speaking, the duty cycle cannot exceed 100% and the PTP core checks for
this.

PHC drivers that don't support this flag emit a periodic output of an
unspecified duty cycle, same as before.

The duty cycle is encoded as an "on" time, similar to the "start" and
"period" times, and reuses the reserved space while preserving overall
binary layout.

Pahole reported before:

struct ptp_perout_request {
struct ptp_clock_time start; /* 0 16 */
struct ptp_clock_time period; /* 16 16 */
unsigned int index; /* 32 4 */
unsigned int flags; /* 36 4 */
unsigned int rsv[4]; /* 40 16 */

/* size: 56, cachelines: 1, members: 5 */
/* last cacheline: 56 bytes */
};

And now:

struct ptp_perout_request {
struct ptp_clock_time start; /* 0 16 */
struct ptp_clock_time period; /* 16 16 */
unsigned int index; /* 32 4 */
unsigned int flags; /* 36 4 */
union {
struct ptp_clock_time on; /* 40 16 */
unsigned int rsv[4]; /* 40 16 */
}; /* 40 16 */

/* size: 56, cachelines: 1, members: 5 */
/* last cacheline: 56 bytes */
};

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: Add adjust_phase to ptp_clock_caps capability.

Add adjust_phase to ptp_clock_caps capability to allow
user to query if a PHC driver supports adjust phase with
ioctl PTP_CLOCK_GETCAPS command.

Signed-off-by: Vincent Cheng <vincent.cheng.xh@renesas.com>
Reviewed-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: Avoid deadlocks in the programmable pin code.

The PTP Hardware Clock (PHC) subsystem offers an API for configuring
programmable pins. User space sets or gets the settings using ioctls,
and drivers verify dialed settings via a callback. Drivers may also
query pin settings by calling the ptp_find_pin() method.

Although the core subsystem protects concurrent access to the pin
settings, the implementation places illogical restrictions on how
drivers may call ptp_find_pin(). When enabling an auxiliary function
via the .enable(on=1) callback, drivers may invoke the pin finding
method, but when disabling with .enable(on=0) drivers are not
permitted to do so. With the exception of the mv88e6xxx, all of the
PHC drivers do respect this restriction, but still the locking pattern
is both confusing and unnecessary.

This patch changes the locking implementation to allow PHC drivers to
freely call ptp_find_pin() from their .enable() and .verify()
callbacks.

V2 ChangeLog:
- fixed spelling in the kernel doc
- add Vladimir's tested by tag

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Reported-by: Yangbo Lu <yangbo.lu@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: Introduce strict checking of external time stamp options.

User space may request time stamps on rising edges, falling edges, or
both. However, the particular mode may or may not be supported in the
hardware or in the driver. This patch adds a "strict" flag that tells
drivers to ensure that the requested mode will be honored.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: Validate requests to enable time stamping of external signals.

Commit 415606588c61 ("PTP: introduce new versions of IOCTLs")
introduced a new external time stamp ioctl that validates the flags.
This patch extends the validation to ensure that at least one rising
or falling edge flag is set when enabling external time stamps.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: correctly disable flags on old ioctls

Commit 415606588c61 ("PTP: introduce new versions of IOCTLs",
2019-09-13) introduced new versions of the PTP ioctls which actually
validate that the flags are acceptable values.

As part of this, it cleared the flags value using a bitwise
and+negation, in an attempt to prevent the old ioctl from accidentally
enabling new features.

This is incorrect for a couple of reasons. First, it results in
accidentally preventing previously working flags on the request ioctl.
By clearing the "valid" flags, we now no longer allow setting the
enable, rising edge, or falling edge flags.

Second, if we add new additional flags in the future, they must not be
set by the old ioctl. (Since the flag wasn't checked before, we could
potentially break userspace programs which sent garbage flag data.

The correct way to resolve this is to check for and clear all but the
originally valid flags.

Create defines indicating which flags are correctly checked and
interpreted by the original ioctls. Use these to clear any bits which
will not be correctly interpreted by the original ioctls.

In the future, new flags must be added to the VALID_FLAGS macros, but
*not* to the V1_VALID_FLAGS macros. In this way, new features may be
exposed over the v2 ioctls, but without breaking previous userspace
which happened to not clear the flags value properly. The old ioctl will
continue to behave the same way, while the new ioctl gains the benefit
of using the flags fields.

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Christopher Hall <christopher.s.hall@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

PTP: introduce new versions of IOCTLs

The current version of the IOCTL have a small problem which prevents us
from extending the API by making use of reserved fields. In these new
IOCTLs, we are now making sure that flags and rsv fields are zero which
will allow us to extend the API in the future.

Reviewed-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
675 mass ave cambridge ma 02139 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 441 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520071858.739733335@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ptp: check that rsv field is zero in struct ptp_sys_offset_extended

Otherwise it is impossible to use it for something else, as it will break
userspace that puts garbage there.

The same check should be done in other structures, but the fact that
data in reserved fields is ignored is already part of the kernel ABI.

Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: deprecate gettime64() in favor of gettimex64()

When a driver provides gettimex64(), use it in the PTP_SYS_OFFSET ioctl
and POSIX clock's gettime() instead of gettime64(). Drivers should
provide only one of the functions.

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: add PTP_SYS_OFFSET_EXTENDED ioctl

The PTP_SYS_OFFSET ioctl, which can be used to measure the offset
between a PHC and the system clock, includes the total time that the
driver needs to read the PHC timestamp.

This typically involves reading of multiple PCI registers (sometimes in
multiple iterations) and the register that contains the lowest bits of
the timestamp is not read in the middle between the two readings of the
system clock. This asymmetry causes the measured offset to have a
significant error.

Introduce a new ioctl, driver function, and helper functions, which
allow the reading of the lowest register to be isolated from the other
readings in order to reduce the asymmetry. The ioctl returns three
timestamps for each measurement:
- system time right before reading the lowest bits of the PHC timestamp
- PHC time
- system time immediately after reading the lowest bits of the PHC
timestamp

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: check gettime64 return code in PTP_SYS_OFFSET ioctl

If a gettime64 call fails, return the error and avoid copying data back
to user.

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: reorder declarations in ptp_ioctl()

Reorder declarations of variables as reversed Christmas tree.

Cc: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: fix Spectre v1 vulnerability

pin_index can be indirectly controlled by user-space, hence leading
to a potential exploitation of the Spectre variant 1 vulnerability.

This issue was detected with the help of Smatch:

drivers/ptp/ptp_chardev.c:253 ptp_ioctl() warn: potential spectre issue
'ops->pin_config' [r] (local cap)

Fix this by sanitizing pin_index before using it to index
ops->pin_config, and before passing it as an argument to
function ptp_set_pinfunc(), in which it is used to index
info->pin_config.

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2

Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: fix missing break in switch

It seems that a *break* is missing in order to avoid falling through
to the default case. Otherwise, checking *chan* makes no sense.

Fixes: 72df7a7244c0 ("ptp: Allow reassigning calibration pin function")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: replace getnstimeofday64() with ktime_get_real_ts64()

getnstimeofday64() is deprecated and getting replaced throughout
the kernel with ktime_get_*() based helpers for a more consistent
interface.

The two functions do the exact same thing, so this is just
a cosmetic change.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

vfs: do bulk POLL* -> EPOLL* replacement

This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

the rest of drivers/*: annotate ->poll() instances

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/ptp: Fix kernel memory disclosure

The reserved field precise_offset->rsv is not cleared before being
copied to user space, leaking kernel stack memory. Clear the struct
before it's copied.

Signed-off-by: Vlad Tsyrklevich <vlad@tsyrklevich.net>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: oops in ptp_ioctl()

If we pass ERR_PTR(-EFAULT) to kfree() then it's going to oops.

Fixes: 2ece068e1b1d ('ptp: use memdup_user().')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: use memdup_user().

Use memdup_user to duplicate a memory region from user-space to
kernel-space, instead of open coding using kmalloc & copy_from_user.

Signed-off-by: Muhammad Falak R Wani <falakreyaz@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: Add PTP_SYS_OFFSET_PRECISE for driver crosstimestamping

Currently, network /system cross-timestamping is performed in the
PTP_SYS_OFFSET ioctl. The PTP clock driver reads gettimeofday() and
the gettime64() callback provided by the driver. The cross-timestamp
is best effort where the latency between the capture of system time
(getnstimeofday()) and the device time (driver callback) may be
significant.

The getcrosststamp() callback and corresponding PTP_SYS_OFFSET_PRECISE
ioctl allows the driver to perform this device/system correlation when
for example cross timestamp hardware is available. Modern Intel
systems can do this for onboard Ethernet controllers using the ART
counter. There is virtually zero latency between captures of the ART
and network device clock.

The capabilities ioctl (PTP_CLOCK_GETCAPS), is augmented allowing
applications to query whether or not drivers implement the
getcrosststamp callback, providing more precise cross timestamping.

Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: kevin.b.stanton@intel.com
Cc: kevin.j.clarke@intel.com
Cc: hpa@zytor.com
Cc: jeffrey.t.kirsher@intel.com
Cc: netdev@vger.kernel.org
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Christopher S. Hall <christopher.s.hall@intel.com>
[jstultz: Commit subject tweaks]
Signed-off-by: John Stultz <john.stultz@linaro.org>

ptp: remove 32 bit get/set methods.

All of the PHC drivers have been converted to the new methods. This patch
converts the three remaining callers within the core code and removes the
older methods for good. As a result, the core PHC code is ready for the
year 2038. However, some of the PHC drivers are not quite ready yet.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: use the 64 bit gettime method for the SYS_OFFSET ioctl.

This patch changes the code to use the new method whenever implemented by
the PHC driver.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: Allow reassigning calibration pin function

The ptp pin function programming does not allow calibration pin to change
function. This is problematic on hardware that uses the default calibration
pin for other purposes.

Removing this limitation does not impact calibration if userspace does not
reprogram the calibration pin.

Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: introduce programmable pins.

This patch adds a pair of new ioctls to the PTP Hardware Clock device
interface. Using the ioctls, user space programs can query each pin to
find out its current function and also reprogram a different function
if desired.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: reduce stack usage when measuring the system time offset

This patch removes the large buffer from the stack of the system
offset ioctl and replaces it with a kmalloced buffer.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: reduce stack usage when reading external time stamps

This patch removes the large buffer from the stack of the read file
operation and replaces it with a kmalloced buffer.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: add an ioctl to compare PHC time with system time

This patch adds an ioctl for PTP Hardware Clock (PHC) devices that allows
user space to measure the time offset between the PHC and the system
clock. Rather than hard coding any kind of estimation algorithm into the
kernel, this patch takes the more flexible approach of just delivering
an array of raw clock readings. In that way, the user space clock servo
may be adapted to new and different hardware clocks.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Acked-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: Fix some locking bugs in ptp_read()

In ptp_read there is an unlock missing on an error path, and a double
unlock on another error path.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: John Stultz <john.stultz@linaro.org>

ptp: Return -EFAULT on copy_to_user() errors

copy_to_user() returns the number of bytes remaining, but we want a
negative error code in ptp_ioctl.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: John Stultz <john.stultz@linaro.org>

ptp: Added a brand new class driver for ptp clocks.

This patch adds an infrastructure for hardware clocks that implement
IEEE 1588, the Precision Time Protocol (PTP). A class driver offers a
registration method to particular hardware clock drivers. Each clock is
presented as a standard POSIX clock.

The ancillary clock features are exposed in two different ways, via
the sysfs and by a character device.

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John Stultz <john.stultz@linaro.org>