This commit introduces the clocks found in the Allwinner A33 CCU.

Since this SoC is very similar to the A23, and we share a significant share
of the DTSI, the clock IDs that are going to be used will also be shared
with the A23, hence the name of the various header files.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NChen-Yu Tsai <wens@csie.org>

Add support for the class with a single factor, N, being a multiplier.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NChen-Yu Tsai <wens@csie.org>

Add a new macro to declare muxes based on a table and a gate.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NChen-Yu Tsai <wens@csie.org>

Some dividers might have a maximum value that is lower than the width of
the register.

Add a field to _ccu_div to handle those case properly. If the field is set
to 0, the code will assume that the maximum value is the maximum one that
can be used with the field register width.

Otherwise, we'll use whatever value has been set.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NChen-Yu Tsai <wens@csie.org>

The internal _ccu_div structure is meant to be embedded into other
structures to combine the various dividers and to form the clock classes
support.

Start to document those structures by using kerneldoc.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

Add some macros to ease the declaration of clocks that are using them.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NChen-Yu Tsai <wens@csie.org>

Add a new style driver for the clock control unit in Allwinner A31/A31s.

A few clocks are still missing:

    - MIPI PLL's HDMI mode support
    - EMAC clock
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

On sunxi we support cpufreq by changing the clock rate of PLL-CPU.
It's possible the clock output of the PLL goes out of the CPU's
operational limits when the PLL's multipliers / dividers are changed
and it hasn't stabilized yet. This would result in the CPU hanging.

To circumvent this, we temporarily switch the CPU mux clock to another
stable clock before the rate change, and switch it back after the PLL
stabilizes. This is done with clk notifiers registered on the PLL.

This patch adds common functions for notifiers to reparent mux clocks.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

Some clocks on the A31 have fixed pre-dividers on multiple parents.
Add support for them.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

Some clock muxes have holes, i.e. invalid or unconnected inputs,
between parent mux values.

Add support for specifying a mux table to map clock parents to
mux values.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

Rename the internal mux macro to be consistent with the other internal
structure macros.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

The MIPI mode of the MIPI-PLL on A31 is an NKM-style PLL with 2
selectable parents.

Add mux support to the NKM clock.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

Some clocks have a predivider value that is larger than what u8 can
store. One such example is the OUT clk found on A20/A31, which has
a /750 pre-divider on one of the osc24M parents.

Increase the size of the div field to u16.
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

Since commit 63a4cc24, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.

No intended functional changes in this commit.
Signed-off-by: NJens Axboe <axboe@fb.com>

The original commit missed this function, it needs to mark it a
write flush.

Cc: Mike Christie <mchristi@redhat.com>
Fixes: e742fc32 ("target: use bio op accessors")
Signed-off-by: NJens Axboe <axboe@fb.com>

Commit abf54548 changed it from an 'rw' flags type to the
newer ops based interface, but now we're effectively leaking
some bdev internals to the rest of the kernel. Since we only
care about whether it's a read or a write at that level, just
pass in a bool 'is_write' parameter instead.

Then we can also move op_is_write() and friends back under
CONFIG_BLOCK protection.
Reviewed-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Instead of a ramoops-specific node, use a child node of /reserved-memory.
This requires that of_platform_device_create() be explicitly called
for the node, though, since "/reserved-memory" does not have its own
"compatible" property.
Suggested-by: NRob Herring <robh@kernel.org>
Signed-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NRob Herring <robh@kernel.org>

Clean up duplicated expression by replacing it with the equivalent local
variable pdev.
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Acked-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

It will be useful to know the hardware configured BAR size to diagnose
issues with NTB memory windows.
Signed-off-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Acked-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

When the link goes down, the link_is_up flag did not return to
false. This could have caused some subtle corner case bugs
when the link goes up and down quickly.

Once that was fixed, there was found to be a race if the link was
brought down then immediately up. The link_cleanup work would
occasionally be scheduled after the next link up event. This would
cancel the link_work that was supposed to occur and leave ntb_perf
in an unusable state.

To fix this we get rid of the link_cleanup work and put the actions
directly in the link_down event.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

This commit adds a debugfs 'count' file to ntb_pingpong. This is so
testing with ntb_pingpong can be automated beyond just checking the
logs for pong messages.

The count file returns a number which increments every pong. The
counter can be cleared by writing a zero.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

In order to more successfully script with ntb_tool it's useful to
have a link file to check the link status so that the script
doesn't use the other files until the link is up.

This commit adds a 'link' file to the debugfs directory which reads
boolean (Y or N) depending on the link status. Writing to the file
change the link state using ntb_link_enable or ntb_link_disable.

A 'link_event' file is also provided so an application can block until
the link changes to the desired state. If the user writes a 1, it will
block until the link is up. If the user writes a 0, it will block until
the link is down.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

In order to make the interface closer to the raw NTB API, this commit
changes memory windows so they are not initialized on link up.
Instead, the 'peer_trans*' debugfs files are introduced. When read,
they return information provided by ntb_mw_get_range. When written,
they create a buffer and initialize the memory window. The
value written is taken as the requested size of the buffer (which
is then rounded for alignment). Writing a value of zero frees the buffer
and tears down the memory window translation. The 'peer_mw*' file is
only created once the memory window translation is setup by the user.

Additionally, it was noticed that the read and write functions for the
'peer_mw*' files should have checked for a NULL pointer.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Instead of returning immediately with an error when the link is
down, wait for the link to come up (or the user sends a SIGINT).

This is to make scripting ntb_perf easier.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Instead of having to watch logs, allow the results to be retrieved
by reading back the run file. This file will return "running" when
the test is running and nothing if no tests have been run yet.
It returns 1 line per thread, and will display an error message if the
corresponding thread returns an error.

With the above change, the pr_info calls that returned the results are
then changed to pr_debug calls.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

This commit accomplishes a few things:

1) Properly prevent multiple sets of threads from running at once using
a mutex. Lots of race issues existed with the thread_cleanup.

2) The mutex allows us to ensure that threads are finished before
tearing down the device or module.

3) Don't use kthread_stop when the threads can exit by themselves, as
this is counter-indicated by the kthread_create documentation. Threads
now wait for kthread_stop to occur.

4) Writing to the run file now blocks until the threads are complete.
The test can then be safely interrupted by a SIGINT.

Also, while I was at it:

5) debugfs_run_write shouldn't return 0 in the early check cases as this
could cause debugfs_run_write to loop undesirably.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

When debugging performance problems, if some issue causes the ntb
hardware to be significantly slower than expected, ntb_perf will
hang requiring a reboot because it only schedules once every 4GB.

Instead, schedule based on jiffies so it will not hang the CPU if
the transfer is slow.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

I'm working on hardware that currently has a limited number of
scratchpad registers and ntb_ndev fails with no clue as to why. I
feel it is better to fail early and provide a reasonable error message
then to fail later on.

The same is done to ntb_perf, but it doesn't currently require enough
spads to actually fail. I've also removed the unused SPAD_MSG and
SPAD_ACK enums so that MAX_SPAD accurately reflects the number of
spads used.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

We allocate some memory window buffers when the link comes up, then we
provide debugfs files to read/write each side of the link.

This is useful for debugging the mapping when writing new drivers.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

On my system, dma_alloc_coherent won't produce memory anywhere
near the size of the BAR. So I needed a way to limit this.

It's pretty much copied straight from ntb_transport.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NDave Jiang <dave.jiang@intel.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

Currently we only allocate a fixed default number of descriptors for the tx
and rx side. We should dynamically resize it to the number of descriptors
resides in the transport rings. We should know the number of transmit
descriptors at initializaiton. We will allocate the default number of
descriptors for receive side and allocate additional ones when we know the
actual max entries for receive.
Signed-off-by: NDave Jiang <dave.jiang@intel.com>
Acked-by: NAllen Hubbe <allen.hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

On hardware with 32 scratchpad registers the spad field in ntb tool
could chop off the end. The maximum buffer size is increased from
256 to 15 times the number or scratchpads.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

If you tried to write two spads in one line, as per the example:

root@peer# echo '0 0x01010101 1 0x7f7f7f7f' > $DBG_DIR/peer_spad

then the CPU would freeze in an infinite loop.

This wasn't immediately obvious but 'pos' was not incrementing the
buffer, so after reading the second pair of values, 'pos' would once
again be 3 and it would re-read the second pair of values ad infinitum.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Acked-by: NAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

If a PCI bridge (or PCIe port) that is runtime-suspended gets an ACPI
hotplug notification, such as a bus check, it has to be resumed before
re-scanning the devices below it, or those devices will not be
accessible and will be treated as hot-removed.

Make that happen and let the bridge suspend again after the bus below it
has been re-scanned.

This is a replacement for commit 16468c78 ("ACPI / hotplug / PCI:
Runtime resume bridge before rescan") that has been reverted, because it
introduced a system resume regression (due to missing bridge->pci_dev
checks that are necessary in case the notification is targeted at the
host bridge) and it is necessary for the code added by commit
006d44e4 ("PCI: Add runtime PM support for PCIe ports") to work as
expected.
Tested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The rw_page users were not converted to use bio/req ops. As a result
bdev_write_page is not passing down REQ_OP_WRITE and the IOs will
be sent down as reads.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Fixes: 4e1b2d52 ("block, fs, drivers: remove REQ_OP compat defs and related code")

Modified by me to:

1) Drop op_flags passing into ->rw_page(), as we don't use it.
2) Make op_is_write() and friends safe to use for !CONFIG_BLOCK
Signed-off-by: NJens Axboe <axboe@fb.com>

Use a switch statement to iterate over the possible operations and
error out if it's an incorrect one.
Signed-off-by: NJens Axboe <axboe@fb.com>

Fix a fat-fingered conversion to the req_op accessors, and also
use a switch statement to make it more obvious what is being checked.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reported-by: NDave Chinner <david@fromorbit.com>
Fixes: c2df40 ("drivers: use req op accessor");
Reviewed-by: NMing Lei <ming.lei@canonical.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Quentin ran into this bug:

WARNING: CPU: 64 PID: 10085 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x65/0x80
sysfs: cannot create duplicate filename '/devices/virtual/block/nbd3/pid'
Modules linked in: nbd
CPU: 64 PID: 10085 Comm: qemu-nbd Tainted: G      D         4.6.0+ #7
 0000000000000000 ffff8820330bba68 ffffffff814b8791 ffff8820330bbac8
 0000000000000000 ffff8820330bbab8 ffffffff810d04ab ffff8820330bbaa8
 0000001f00000296 0000000000017681 ffff8810380bf000 ffffffffa0001790
Call Trace:
 [<ffffffff814b8791>] dump_stack+0x4d/0x6c
 [<ffffffff810d04ab>] __warn+0xdb/0x100
 [<ffffffff810d0574>] warn_slowpath_fmt+0x44/0x50
 [<ffffffff81218c65>] sysfs_warn_dup+0x65/0x80
 [<ffffffff81218a02>] sysfs_add_file_mode_ns+0x172/0x180
 [<ffffffff81218a35>] sysfs_create_file_ns+0x25/0x30
 [<ffffffff81594a76>] device_create_file+0x36/0x90
 [<ffffffffa0000e8d>] __nbd_ioctl+0x32d/0x9b0 [nbd]
 [<ffffffff814cc8e8>] ? find_next_bit+0x18/0x20
 [<ffffffff810f7c29>] ? select_idle_sibling+0xe9/0x120
 [<ffffffff810f6cd7>] ? __enqueue_entity+0x67/0x70
 [<ffffffff810f9bf0>] ? enqueue_task_fair+0x630/0xe20
 [<ffffffff810efa76>] ? resched_curr+0x36/0x70
 [<ffffffff810f0078>] ? check_preempt_curr+0x78/0x90
 [<ffffffff810f00a2>] ? ttwu_do_wakeup+0x12/0x80
 [<ffffffff810f01b1>] ? ttwu_do_activate.constprop.86+0x61/0x70
 [<ffffffff810f0c15>] ? try_to_wake_up+0x185/0x2d0
 [<ffffffff810f0d6d>] ? default_wake_function+0xd/0x10
 [<ffffffff81105471>] ? autoremove_wake_function+0x11/0x40
 [<ffffffffa0001577>] nbd_ioctl+0x67/0x94 [nbd]
 [<ffffffff814ac0fd>] blkdev_ioctl+0x14d/0x940
 [<ffffffff811b0da2>] ? put_pipe_info+0x22/0x60
 [<ffffffff811d96cc>] block_ioctl+0x3c/0x40
 [<ffffffff811ba08d>] do_vfs_ioctl+0x8d/0x5e0
 [<ffffffff811aa329>] ? ____fput+0x9/0x10
 [<ffffffff810e9092>] ? task_work_run+0x72/0x90
 [<ffffffff811ba627>] SyS_ioctl+0x47/0x80
 [<ffffffff8185f5df>] entry_SYSCALL_64_fastpath+0x17/0x93
---[ end trace 7899b295e4f850c8 ]---

It seems fairly obvious that device_create_file() is not being protected
from being run concurrently on the same nbd.

Quentin found the following relevant commits:

1a2ad211 nbd: add locking to nbd_ioctl
90b8f282 [PATCH] end of methods switch: remove the old ones
d4430d62 [PATCH] beginning of methods conversion
08f85851 [PATCH] move block_device_operations to blkdev.h

It would seem that the race was introduced in the process of moving nbd
from BKL to unlocked ioctls.

By setting nbd->task_recv while the mutex is held, we can prevent other
processes from running concurrently (since nbd->task_recv is also checked
while the mutex is held).
Reported-and-tested-by: NQuentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Markus Pargmann <mpa@pengutronix.de>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Pavel Machek <pavel@suse.cz>
Cc: Jens Axboe <axboe@fb.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NVegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Commit 09954bad ("floppy: refactor open() flags handling"), as a
side-effect, causes open(/dev/fdX, O_ACCMODE) to fail. It turns out that
this is being used setfdprm userspace for ioctl-only open().

Reintroduce back the original behavior wrt !(FMODE_READ|FMODE_WRITE)
modes, while still keeping the original O_NDELAY bug fixed.

Cc: stable@vger.kernel.org # v4.5+
Reported-by: NWim Osterholt <wim@djo.tudelft.nl>
Tested-by: NWim Osterholt <wim@djo.tudelft.nl>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

buf[0] is an unsigned char.  touch_nr is an int.  The test for negative
here doesn't make sense so I have removed it.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>