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767209 commits

Author SHA1 Message Date
Michał Winiarski
adbe6cfe59 media: rc: nuvoton: Keep track of users on CIR enable/disable
Core rc keeps track of the users - let's use it to tweak the code and
use the common code path on suspend/resume.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 17:37:42 -04:00
Michał Winiarski
70c30b1ea7 media: rc: nuvoton: Tweak the interrupt enabling dance
It appears that we need to enable CIR device before attempting to touch
some of the registers. Previously, this was not a big issue, since we
were rarely seeing nvt_close() getting called.

Unfortunately, since commit cb84343fce ("media: lirc: do not call close()
or open() on unregistered devices") the initial open() during probe from
rc_setup_rx_device() is no longer successful, which means that userspace
clients will actually end up calling nvt_open()/nvt_close(). Since
nvt_open() is broken, the device doesn't seem to work as expected.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199597

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 17:36:31 -04:00
Rafael J. Wysocki
74cd8171c4 PM / QoS: Drop redundant declaration of pm_qos_get_value()
The extra forward declaration of pm_qos_get_value() is redundant, so
drop it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-28 23:21:41 +02:00
ming_qian
f620d1d7af media: uvcvideo: Support realtek's UVC 1.5 device
media: uvcvideo: Support UVC 1.5 video probe & commit controls

The length of UVC 1.5 video control is 48, and it is 34 for UVC 1.1.
Change it to 48 for UVC 1.5 device, and the UVC 1.5 device can be
recognized.

More changes to the driver are needed for full UVC 1.5 compatibility.
However, at least the UVC 1.5 Realtek RTS5847/RTS5852 cameras have been
reported to work well.

[laurent.pinchart@ideasonboard.com: Factor out code to helper function, update size checks]

Cc: stable@vger.kernel.org
Signed-off-by: ming_qian <ming_qian@realsil.com.cn>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Ana Guerrero Lopez <ana.guerrero@collabora.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:59:55 -04:00
Andy Shevchenko
ce4c3e19e5 bcache: Replace bch_read_string_list() by __sysfs_match_string()
Kernel library has a common function to match user input from sysfs
against an array of strings. Thus, replace bch_read_string_list() by
__sysfs_match_string().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-28 14:53:22 -06:00
Andy Shevchenko
ecb37ce9ba bcache: Move couple of functions to sysfs.c
There is couple of functions that are used exclusively in sysfs.c.
Move it to there and make them static.

Besides above, it will allow further clean up.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-28 14:53:20 -06:00
Andy Shevchenko
04cbc21137 bcache: Move couple of string arrays to sysfs.c
There is couple of string arrays that are used exclusively in sysfs.c.
Move it to there and make them static.

Besides above, it will allow further clean up.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-28 14:53:18 -06:00
Coly Li
0f0709e6bf bcache: stop bcache device when backing device is offline
Currently bcache does not handle backing device failure, if backing
device is offline and disconnected from system, its bcache device can still
be accessible. If the bcache device is in writeback mode, I/O requests even
can success if the requests hit on cache device. That is to say, when and
how bcache handles offline backing device is undefined.

This patch tries to handle backing device offline in a rather simple way,
- Add cached_dev->status_update_thread kernel thread to update backing
  device status in every 1 second.
- Add cached_dev->offline_seconds to record how many seconds the backing
  device is observed to be offline. If the backing device is offline for
  BACKING_DEV_OFFLINE_TIMEOUT (30) seconds, set dc->io_disable to 1 and
  call bcache_device_stop() to stop the bache device which linked to the
  offline backing device.

Now if a backing device is offline for BACKING_DEV_OFFLINE_TIMEOUT seconds,
its bcache device will be removed, then user space application writing on
it will get error immediately, and handler the device failure in time.

This patch is quite simple, does not handle more complicated situations.
Once the bcache device is stopped, users need to recovery the backing
device, register and attach it manually.

Changelog:
v3: call wait_for_kthread_stop() before exits kernel thread.
v2: remove "bcache: " prefix when calling pr_warn().
v1: initial version.

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Michael Lyle <mlyle@lyle.org>
Cc: Junhui Tang <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-28 14:53:16 -06:00
Philipp Zabel
f9ffcb0a21 media: uvcvideo: Fix driver reference counting
kref_init initializes the reference count to 1, not 0. This additional
reference is never released since the conversion to reference counters.
As a result, uvc_delete is not called anymore when UVC cameras are
disconnected.
Fix this by adding an additional kref_put in uvc_disconnect and in the
probe error path. This also allows to remove the temporary additional
reference in uvc_unregister_video.

Fixes: 9d15cd958c ("media: uvcvideo: Convert from using an atomic variable to a reference count")

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:49:47 -04:00
Ondrej Zary
6c0e931c74 media: gspca_zc3xx: Enable short exposure times for OV7648
The 50Hz and 60Hz power line frequency settings disable short (1/120s
and 1/100s) exposure times for banding filter (causing overexposed
image near lamps). No flicker setting enables them (when banding
filter is disabled and they're not used).

Seems that the logic is just the wrong way around.
(This bug came from the Windows driver.)

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:35:41 -04:00
Ondrej Zary
8945dead54 media: gspca_zc3xx: Fix power line frequency settings for OV7648
Power line frequency settings for OV7648 sensor contain autogain
and exposure commands, affecting unrelated controls. Remove them.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:34:47 -04:00
Ondrej Zary
6f92c3a22c media: gspca_zc3xx: Implement proper autogain and exposure control for OV7648
The ZS0211 internal autogain causes pumping and flickering with OV7648
sensor on 0ac8:307b webcam.
Implement OV7648 autogain and exposure control and use that instead.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:33:37 -04:00
Hans Verkuil
73a110623e media: v4l2-core: push taking ioctl mutex down to ioctl handler
The ioctl serialization mutex (vdev->lock or q->lock for vb2 queues)
was taken at the highest level in v4l2-dev.c. This prevents more
fine-grained locking since at that level we cannot examine the ioctl
arguments, we can only do that after video_usercopy is called.

So push the locking down to __video_do_ioctl() and subdev_do_ioctl_lock().

This also allows us to make a few functions in v4l2-ioctl.c static and
video_usercopy() is no longer exported.

The locking scheme is not changed by this patch, just pushed down.

Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:31:44 -04:00
Hans Verkuil
eba09b5b3d media: pvrusb2: replace pvr2_v4l2_ioctl by video_ioctl2
This driver is the only V4L driver that does not set unlocked_ioctl
to video_ioctl2.

The only thing that pvr2_v4l2_ioctl does besides calling video_ioctl2
is calling pvr2_hdw_commit_ctl(). Add pvr2_hdw_commit_ctl() calls to
the various ioctls that need this, and we can replace pvr2_v4l2_ioctl
by video_ioctl2.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:28:09 -04:00
Gustavo A. R. Silva
b3b2d5b624 media: au8522: remove duplicate code
This code has been there for nine years now, and it has been
working "good enough" since then [1].

Remove duplicate code by getting rid of the if-else statement.

[1] https://marc.info/?l=linux-kernel&m=152693550225081&w=2

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:26:38 -04:00
Hans Verkuil
00f6f92dbb media: adv7511: fix incorrect clear of CEC receive interrupt
If a CEC message was received and the RX interrupt was set, but
not yet processed, and a new transmit was issues, then the
transmit code would inadvertently clear the RX interrupt and
after that no new messages would ever be received.

Instead it should only clear TX interrupts since register 0x97
is a clear-on-write register.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:25:45 -04:00
Hans Verkuil
7367815849 media: cec: fix wrong tx/rx_status values when canceling a msg
When a message was canceled it could return tx_status with
both OK and MAX_RETRIES set, which is illegal.

If a canceled message was waiting for a reply, then rx_status
wasn't updated, so set that as well.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:25:25 -04:00
Colin Ian King
4ba610c8dc media: hdpvr: fix spelling mistake: "Hauppage" -> "Hauppauge"
Trivial fix to spelling mistake in name field

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:24:50 -04:00
Akinobu Mita
94ae1d6ba6 media: pxa_camera: avoid duplicate s_power calls
The open() operation for the pxa_camera driver always calls s_power()
operation to put its subdevice sensor in normal operation mode, and the
release() operation always call s_power() operation to put the subdevice
in power saving mode.

This requires the subdevice sensor driver to keep track of its power
state in order to avoid putting the subdevice in power saving mode while
the device is still opened by some users.

Many subdevice drivers handle it by the boilerplate code that increments
and decrements an internal counter in s_power() like below:

	/*
	 * If the power count is modified from 0 to != 0 or from != 0 to 0,
	 * update the power state.
	 */
	if (sensor->power_count == !on) {
		ret = ov5640_set_power(sensor, !!on);
		if (ret)
			goto out;
	}

	/* Update the power count. */
	sensor->power_count += on ? 1 : -1;

However, some subdevice drivers don't handle it and may cause a problem
with the pxa_camera driver if the video device is opened by more than
two users at the same time.

Instead of propagating the boilerplate code for each subdevice driver
that implement s_power, this introduces an trick that many V4L2 drivers
are using with v4l2_fh_is_singular_file().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:24:30 -04:00
Dmitry Osipenko
f68bbb2325 media: staging: tegra-vde: Reset memory client
DMA requests must be blocked before resetting VDE HW, otherwise it is
possible to get a memory corruption or a machine hang. Use the reset
control provided by the Memory Controller to block DMA before resetting
the VDE HW.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:22:58 -04:00
Ezequiel Garcia
636757ab6c media: tw686x: Fix incorrect vb2_mem_ops GFP flags
When the driver is configured in the "memcpy" dma-mode,
it uses vb2_vmalloc_memops, which is backed by a SLAB
allocator and so shouldn't be using GFP_DMA32.

Fix it.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:21:41 -04:00
Ezequiel Garcia
9e73d231b8 media: m2m-deinterlace: Remove DMA_ENGINE dependency
The DMA engine subsystem provides stubs for drivers
to build with !DMA_ENGINE. Drop the config dependency.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:20:25 -04:00
Ezequiel Garcia
31fa0d12c4 media: stk1160: Add missing calls to mutex_destroy
The mutexes are not being destroyed in the release path. Fix it.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:20:01 -04:00
Ezequiel Garcia
9141386c69 media: stk1160: Fix typo s/therwise/Otherwise
Fix a trivial typo.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:19:29 -04:00
Geert Uytterhoeven
4cff79e933 media: Remove depends on HAS_DMA in case of platform dependency
Remove dependencies on HAS_DMA where a Kconfig symbol depends on another
symbol that implies HAS_DMA, and, optionally, on "|| COMPILE_TEST".
In most cases this other symbol is an architecture or platform specific
symbol, or PCI.

Generic symbols and drivers without platform dependencies keep their
dependencies on HAS_DMA, to prevent compiling subsystems or drivers that
cannot work anyway.

This simplifies the dependencies, and allows to improve compile-testing.

Note:
  - The various VIDEOBUF*DMA* symbols had to loose their dependencies on
    HAS_DMA, as they are selected by several individual drivers.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:17:08 -04:00
Dan Carpenter
9329e7b03c media: vivid: potential integer overflow in vidioc_g_edid()
If we pick a very large "edid->blocks" value then the "edid->start_block
+ edid->blocks" addition could wrap around.

Fixes: ef834f7836 ("[media] vivid: add the video capture and output parts")

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:12:07 -04:00
Mauro Carvalho Chehab
a3d71f256c media: cec-pin-error-inj: avoid a false-positive Spectre detection
The current logic makes Smatch to false-detect a Spectre variant 1
vulnerability. The problem is that it initializes an u32 indirectly
from user space input.

After trying to write a fixup, after a while I realized that, in
practice, this shouldn't be a problem, as an u32 is initialized
from u8, but it took some time to discover it.

So, do some code cleanup to make it clearer for both humans
and machines about the valid range for "op".

Fix this warning:
	drivers/media/cec/cec-pin-error-inj.c:170 cec_pin_error_inj_parse_line() warn: potential spectre issue 'pin->error_inj_args'

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:11:17 -04:00
Ezequiel Garcia
6992effe53 media: gspca: Kill all URBs before releasing any of them
Some subdrivers access the gspca_dev->urb array in the completion handler.
To prevent use-after-free (actually, NULL dereferences) we need to
synchronously kill all the URBs before we release them.

In particular, this is currently the case for drivers such
as sn9c20x and sonixj, which access the gspca_dev->urb[0]
in the context of completion handler for *any* of the URBs.

This commit changes the destroy_urb implementation, so it kills
all URBs first, and then proceed to set the URBs to NULL in the
array and release them.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:05:03 -04:00
Hans Verkuil
df95e82f6b media: gspca: fix g/s_parm handling
Fix v4l2-compliance error: s_parm never set V4L2_CAP_TIMEPERFRAME.
Also various g/s_parm-related cleanups.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 16:02:45 -04:00
Hans Verkuil
0d5615d347 media: v4l2-ioctl: delete unused v4l2_disable_ioctl_locking
The last user of this 'feature' was the gspca driver. Now that
that driver has been converted to vb2 we can delete this code.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 15:58:49 -04:00
Hans Verkuil
8a7c5594c0 media: v4l2-ioctl: clear fields in s_parm
Zero the reserved capture/output array.

Zero the extendedmode (it is never used in drivers).

Clear all flags in capture/outputmode except for V4L2_MODE_HIGHQUALITY,
as that is the only valid flag.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 15:58:06 -04:00
Hans Verkuil
1f5965c4df media: gspca: convert to vb2
The gspca core has its own buffere implementation. Use the
core VB 2 instead.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 15:57:17 -04:00
Hans Verkuil
90b2da89a0 media: videobuf2-core: don't call memop 'finish' when queueing
When a buffer is queued or requeued in vb2_buffer_done, then don't
call the finish memop. In this case the buffer is only returned to vb2,
not to userspace.

Calling 'finish' here will cause an unbalance when the queue is
canceled, since the core will call the same memop again.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-28 15:51:46 -04:00
Masahiro Yamada
e1cfdc0e72 kconfig: add basic helper macros to scripts/Kconfig.include
Kconfig got text processing tools like we see in Make.  Add Kconfig
helper macros to scripts/Kconfig.include like we collect Makefile
macros in scripts/Kbuild.include.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
21c54b7747 kconfig: show compiler version text in the top comment
The kernel configuration phase is now tightly coupled with the compiler
in use.  It will be nice to show the compiler information in Kconfig.

The compiler information will be displayed like this:

  $ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- config
  scripts/kconfig/conf  --oldaskconfig Kconfig
  *
  * Linux/arm64 4.16.0-rc1 Kernel Configuration
  *
  *
  * Compiler: aarch64-linux-gnu-gcc (Linaro GCC 7.2-2017.11) 7.2.1 20171011
  *
  *
  * General setup
  *
  Compile also drivers which will not load (COMPILE_TEST) [N/y/?]

If you use GUI methods such as menuconfig, it will be displayed in the
top menu.

This is simply implemented by using the 'comment' statement.  So, it
will be saved into the .config file as well.

This commit has a very important meaning.  If the compiler is upgraded,
Kconfig must be re-run since different compilers have different sets
of supported options.

All referenced environments are written to include/config/auto.conf.cmd
so that any environment change triggers syncconfig, and prompt the user
to input new values if needed.

With this commit, something like follows will be added to
include/config/auto.conf.cmd

  ifneq "$(CC_VERSION_TEXT)" "aarch64-linux-gnu-gcc (Linaro GCC 7.2-2017.11) 7.2.1 20171011"
  include/config/auto.conf: FORCE
  endif

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
2bece88f89 kconfig: test: add Kconfig macro language tests
Here are the test cases I used for developing the text expansion
feature.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
316d55d55f Documentation: kconfig: document a new Kconfig macro language
Add a document for the macro language introduced to Kconfig.

The motivation of this work is to move the compiler option tests to
Kconfig from Makefile.  A number of kernel features require the
compiler support.  Enabling such features blindly in Kconfig ends up
with a lot of nasty build-time testing in Makefiles.  If a chosen
feature turns out unsupported by the compiler, what the build system
can do is either to disable it (silently!) or to forcibly break the
build, despite Kconfig has let the user to enable it.  By moving the
compiler capability tests to Kconfig, features unsupported by the
compiler will be hidden automatically.

This change was strongly prompted by Linus Torvalds.  You can find
his suggestions [1] [2] in ML.  The original idea was to add a new
attribute with 'option shell=...', but I found more generalized text
expansion would make Kconfig more powerful and lovely.  The basic
ideas are from Make, but there are some differences.

[1]: https://lkml.org/lkml/2016/12/9/577
[2]: https://lkml.org/lkml/2018/2/7/527

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
915f64901e kconfig: error out if a recursive variable references itself
When using a recursively expanded variable, it is a common mistake
to make circular reference.

For example, Make terminates the following code:

  X = $(X)
  Y := $(X)

Let's detect the circular expansion in Kconfig, too.

On the other hand, a function that recurses itself is a commonly-used
programming technique.  So, Make does not check recursion in the
reference with 'call'.  For example, the following code continues
running eternally:

  X = $(call X)
  Y := $(X)

Kconfig allows circular expansion if one or more arguments are given,
but terminates when the same function is recursively invoked 1000 times,
assuming it is a programming mistake.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
a702a6176e kconfig: add 'filename' and 'lineno' built-in variables
The special variables, $(filename) and $(lineno), are expanded to a
file name and its line number being parsed, respectively.

Suggested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
1d6272e6fe kconfig: add 'info', 'warning-if', and 'error-if' built-in functions
Syntax:
  $(info,<text>)
  $(warning-if,<condition>,<text>)
  $(error-if,<condition>,<text)

The 'info' function prints a message to stdout as in Make.

The 'warning-if' and 'error-if' are similar to 'warning' and 'error'
in Make, but take the condition parameter.  They are effective only
when the <condition> part is y.

Kconfig does not implement the lazy expansion as used in the 'if'
'and, 'or' functions in Make.  In other words, Kconfig does not
support conditional expansion.  The unconditional 'error' function
would always terminate the parsing, hence would be useless in Kconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
82bc8bd82e kconfig: expand lefthand side of assignment statement
Make expands the lefthand side of assignment statements.  In fact,
Kbuild relies on it since kernel makefiles mostly look like this:

  obj-$(CONFIG_FOO) += foo.o

Do likewise in Kconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
ed2a22f277 kconfig: support append assignment operator
Support += operator.  This appends a space and the text on the
righthand side to a variable.

The timing of the evaluation of the righthand side depends on the
flavor of the variable.  If the lefthand side was originally defined
as a simple variable, the righthand side is expanded immediately.
Otherwise, the expansion is deferred.  Appending something to an
undefined variable results in a recursive variable.

To implement this, we need to remember the flavor of variables.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
1175c02506 kconfig: support simply expanded variable
The previous commit added variable and user-defined function.  They
work similarly in the sense that the evaluation is deferred until
they are used.

This commit adds another type of variable, simply expanded variable,
as we see in Make.

The := operator defines a simply expanded variable, expanding the
righthand side immediately.  This works like traditional programming
language variables.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
9ced3bddec kconfig: support user-defined function and recursively expanded variable
Now, we got a basic ability to test compiler capability in Kconfig.

config CC_HAS_STACKPROTECTOR
        def_bool $(shell,($(CC) -Werror -fstack-protector -E -x c /dev/null -o /dev/null 2>/dev/null) && echo y || echo n)

This works, but it is ugly to repeat this long boilerplate.

We want to describe like this:

config CC_HAS_STACKPROTECTOR
        bool
        default $(cc-option,-fstack-protector)

It is straight-forward to add a new function, but I do not like to
hard-code specialized functions like that.  Hence, here is another
feature, user-defined function.  This works as a textual shorthand
with parameterization.

A user-defined function is defined by using the = operator, and can
be referenced in the same way as built-in functions.  A user-defined
function in Make is referenced like $(call my-func,arg1,arg2), but I
omitted the 'call' to make the syntax shorter.

The definition of a user-defined function contains $(1), $(2), etc.
in its body to reference the parameters.  It is grammatically valid
to pass more or fewer arguments when calling it.  We already exploit
this feature in our makefiles; scripts/Kbuild.include defines cc-option
which takes two arguments at most, but most of the callers pass only
one argument.

By the way, a variable is supported as a subset of this feature since
a variable is "a user-defined function with zero argument".  In this
context, I mean "variable" as recursively expanded variable.  I will
add a different flavored variable in the next commit.

The code above can be written as follows:

[Example Code]

  success = $(shell,($(1)) >/dev/null 2>&1 && echo y || echo n)
  cc-option = $(success,$(CC) -Werror $(1) -E -x c /dev/null -o /dev/null)

  config CC_HAS_STACKPROTECTOR
          def_bool $(cc-option,-fstack-protector)

[Result]
  $ make -s alldefconfig && tail -n 1 .config
  CONFIG_CC_HAS_STACKPROTECTOR=y

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
9de071536c kconfig: begin PARAM state only when seeing a command keyword
Currently, any statement line starts with a keyword with TF_COMMAND
flag.  So, the following three lines are dead code.

        alloc_string(yytext, yyleng);
        zconflval.string = text;
        return T_WORD;

If a T_WORD token is returned in this context, it will cause syntax
error in the parser anyway.

The next commit will support the assignment statement where a line
starts with an arbitrary identifier.  So, I want the lexer to switch
to the PARAM state only when it sees a command keyword.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
2972666ac9 kconfig: replace $(UNAME_RELEASE) with function call
Now that 'shell' function is supported, this can be self-contained in
Kconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
2fd5b09c20 kconfig: add 'shell' built-in function
This accepts a single command to execute.  It returns the standard
output from it.

[Example code]

  config HELLO
          string
          default "$(shell,echo hello world)"

  config Y
          def_bool $(shell,echo y)

[Result]

  $ make -s alldefconfig && tail -n 2 .config
  CONFIG_HELLO="hello world"
  CONFIG_Y=y

Caveat:
Like environments, functions are expanded in the lexer.  You cannot
pass symbols to function arguments.  This is a limitation to simplify
the implementation.  I want to avoid the dynamic function evaluation,
which would introduce much more complexity.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
e298f3b49d kconfig: add built-in function support
This commit adds a new concept 'function' to do more text processing
in Kconfig.

A function call looks like this:

  $(function,arg1,arg2,arg3,...)

This commit adds the basic infrastructure to expand functions.
Change the text expansion helpers to take arguments.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
137c0118a9 kconfig: make default prompt of mainmenu less specific
If "mainmenu" is not specified, "Linux Kernel Configuration" is used
as a default prompt.

Given that Kconfig is used in other projects than Linux, let's use
a more generic prompt, "Main menu".

Suggested-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-29 03:31:19 +09:00
Masahiro Yamada
5b31a97467 kconfig: remove sym_expand_string_value()
There is no more caller of sym_expand_string_value().

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2018-05-29 03:31:19 +09:00