linux-toradex.git/drivers/base/Kconfig, branch v4.4.93

cma: make default CMA area size zero for x86

2014-12-11T01:41:06+00:00

This makes CMA memory area size zero for x86 in default configuration
(doesn't change on the other architectures).  If default CMA size is
zero, DMA_CMA is disabled.  It can be enabled by passing cma= to the
kernel.

This makes less impact on x86.  Because there is no mainline driver that
requires it for x86, and Peter Hurley reported the performance
regression, as this is trying to drive _all_ dma mapping allocations
through a _very_ small window.

Signed-off-by: Akinobu Mita 
Reported-by: Peter Hurley 
Cc: Peter Hurley 
Cc: Chuck Ebbert 
Cc: Jean Delvare 
Acked-by: Marek Szyprowski 
Cc: Konrad Rzeszutek Wilk 
Cc: David Woodhouse 
Cc: Don Dutile 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Andi Kleen 
Cc: Yinghai Lu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tiny: rename ENABLE_DEV_COREDUMP to ALLOW_DEV_COREDUMP

2014-11-07T19:07:35+00:00

The ENABLE_DEV_COREDUMP option is misleading as it implies that
it gets the framework enabled, this isn't true it just allows it
to get enabled if a driver needs it.

Rename it to ALLOW_DEV_COREDUMP to better capture its semantics.

Signed-off-by: Johannes Berg 
Reviewed-by: Josh Triplett 
Acked-by: Aristeu Rozanski 
Signed-off-by: Greg Kroah-Hartman

tiny: reverse logic for DISABLE_DEV_COREDUMP

2014-11-07T19:07:35+00:00

It's desirable for allnconfig and tinyconfig targets to result in the
least amount of code possible. DISABLE_DEV_COREDUMP exists as a way to
switch off DEV_COREDUMP regardless if any drivers select
WANT_DEV_COREDUMP.

This patch renames the option to ENABLE_DEV_COREDUMP and setting it to
'n' (as in allnconfig or tinyconfig) will effectively disable device
coredump.

Cc: Josh Triplett 
Reviewed-by: Josh Triplett 
Signed-off-by: Aristeu Rozanski 
Reviewed-by: Johannes Berg 
Acked-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

CMA: document cma=0

2014-10-10T02:26:02+00:00

It isn't obvious that CMA can be disabled on the kernel's command line, so
document it.

Signed-off-by: Jean Delvare 
Cc: Joonsoo Kim 
Cc: Greg Kroah-Hartman 
Cc: Akinobu Mita 
Cc: Chuck Ebbert 
Cc: Marek Szyprowski 
Cc: Konrad Rzeszutek Wilk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

device coredump: add new device coredump class

2014-09-24T05:53:15+00:00

Many devices run firmware and/or complex hardware, and most of that
can have bugs. When it misbehaves, however, it is often much harder
to debug than software running on the host.

Introduce a "device coredump" mechanism to allow dumping internal
device/firmware state through a generalized mechanism. As devices
are different and information needed can vary accordingly, this
doesn't prescribe a file format - it just provides mechanism to
get data to be able to capture it in a generalized way (e.g. in
distributions.)

The dumped data will be readable in sysfs in the virtual device's
data file under /sys/class/devcoredump/devcd*/. Writing to it will
free the data and remove the device, as does a 5-minute timeout.

Note that generalized capturing of such data may result in privacy
issues, so users generally need to be involved. In order to allow
certain users/system integrators/... to disable the feature at all,
introduce a Kconfig option to override the drivers that would like
to have the feature.

For now, this provides two ways of dumping data:
 1) with a vmalloc'ed area, that is then given to the subsystem
    and freed after retrieval or timeout
 2) with a generalized reader/free function method

We could/should add more options, e.g. a list of pages, since the
vmalloc area is very limited on some architectures.

Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

CMA: generalize CMA reserved area management functionality

2014-08-07T01:01:16+00:00

Currently, there are two users on CMA functionality, one is the DMA
subsystem and the other is the KVM on powerpc.  They have their own code
to manage CMA reserved area even if they looks really similar.  From my
guess, it is caused by some needs on bitmap management.  KVM side wants
to maintain bitmap not for 1 page, but for more size.  Eventually it use
bitmap where one bit represents 64 pages.

When I implement CMA related patches, I should change those two places
to apply my change and it seem to be painful to me.  I want to change
this situation and reduce future code management overhead through this
patch.

This change could also help developer who want to use CMA in their new
feature development, since they can use CMA easily without copying &
pasting this reserved area management code.

In previous patches, we have prepared some features to generalize CMA
reserved area management and now it's time to do it.  This patch moves
core functions to mm/cma.c and change DMA APIs to use these functions.

There is no functional change in DMA APIs.

Signed-off-by: Joonsoo Kim 
Acked-by: Michal Nazarewicz 
Acked-by: Zhang Yanfei 
Acked-by: Minchan Kim 
Reviewed-by: Aneesh Kumar K.V 
Cc: Alexander Graf 
Cc: Aneesh Kumar K.V 
Cc: Gleb Natapov 
Acked-by: Marek Szyprowski 
Tested-by: Marek Szyprowski 
Cc: Paolo Bonzini 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

firmware loader: allow disabling of udev as firmware loader

2014-07-08T22:24:39+00:00

[The patch was originally proposed by Tom Gundersen, and rewritten
 afterwards by me; most of changelogs below borrowed from Tom's
 original patch -- tiwai]

Currently (at least) the dell-rbu driver selects FW_LOADER_USER_HELPER,
which means that distros can't really stop loading firmware through
udev without breaking other users (though some have).

Ideally we would remove/disable the udev firmware helper in both the
kernel and in udev, but if we were to disable it in udev and not the
kernel, the result would be (seemingly) hung kernels as no one would
be around to cancel firmware requests.

This patch allows udev firmware loading to be disabled while still
allowing non-udev firmware loading, as done by the dell-rbu driver, to
continue working. This is achieved by only using the fallback
mechanism when the uevent is suppressed.

The patch renames the user-selectable Kconfig from FW_LOADER_USER_HELPER
to FW_LOADER_USER_HELPER_FALLBACK, and the former is reverse-selected
by the latter or the drivers that need userhelper like dell-rbu.

Also, the "default y" is removed together with this change, since it's
been deprecated in udev upstream, thus rather better to disable it
nowadays.

Tested with
    FW_LOADER_USER_HELPER=n
    LATTICE_ECP3_CONFIG=y
    DELL_RBU=y
and udev without the firmware loading support, but I don't have the
hardware to test the lattice/dell drivers, so additional testing would
be appreciated.

Reviewed-by: Tom Gundersen 
Cc: Ming Lei 
Cc: Abhay Salunke 
Cc: Stefan Roese 
Cc: Arnd Bergmann 
Cc: Kay Sievers 
Tested-by: Balaji Singh 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman

fence: dma-buf cross-device synchronization (v18)

2014-07-08T19:18:56+00:00

A fence can be attached to a buffer which is being filled or consumed
by hw, to allow userspace to pass the buffer without waiting to another
device.  For example, userspace can call page_flip ioctl to display the
next frame of graphics after kicking the GPU but while the GPU is still
rendering.  The display device sharing the buffer with the GPU would
attach a callback to get notified when the GPU's rendering-complete IRQ
fires, to update the scan-out address of the display, without having to
wake up userspace.

A driver must allocate a fence context for each execution ring that can
run in parallel. The function for this takes an argument with how many
contexts to allocate:
  + fence_context_alloc()

A fence is transient, one-shot deal.  It is allocated and attached
to one or more dma-buf's.  When the one that attached it is done, with
the pending operation, it can signal the fence:
  + fence_signal()

To have a rough approximation whether a fence is fired, call:
  + fence_is_signaled()

The dma-buf-mgr handles tracking, and waiting on, the fences associated
with a dma-buf.

The one pending on the fence can add an async callback:
  + fence_add_callback()

The callback can optionally be cancelled with:
  + fence_remove_callback()

To wait synchronously, optionally with a timeout:
  + fence_wait()
  + fence_wait_timeout()

When emitting a fence, call:
  + trace_fence_emit()

To annotate that a fence is blocking on another fence, call:
  + trace_fence_annotate_wait_on(fence, on_fence)

A default software-only implementation is provided, which can be used
by drivers attaching a fence to a buffer when they have no other means
for hw sync.  But a memory backed fence is also envisioned, because it
is common that GPU's can write to, or poll on some memory location for
synchronization.  For example:

  fence = custom_get_fence(...);
  if ((seqno_fence = to_seqno_fence(fence)) != NULL) {
    dma_buf *fence_buf = seqno_fence->sync_buf;
    get_dma_buf(fence_buf);

    ... tell the hw the memory location to wait ...
    custom_wait_on(fence_buf, seqno_fence->seqno_ofs, fence->seqno);
  } else {
    /* fall-back to sw sync * /
    fence_add_callback(fence, my_cb);
  }

On SoC platforms, if some other hw mechanism is provided for synchronizing
between IP blocks, it could be supported as an alternate implementation
with it's own fence ops in a similar way.

enable_signaling callback is used to provide sw signaling in case a cpu
waiter is requested or no compatible hardware signaling could be used.

The intention is to provide a userspace interface (presumably via eventfd)
later, to be used in conjunction with dma-buf's mmap support for sw access
to buffers (or for userspace apps that would prefer to do their own
synchronization).

v1: Original
v2: After discussion w/ danvet and mlankhorst on #dri-devel, we decided
    that dma-fence didn't need to care about the sw->hw signaling path
    (it can be handled same as sw->sw case), and therefore the fence->ops
    can be simplified and more handled in the core.  So remove the signal,
    add_callback, cancel_callback, and wait ops, and replace with a simple
    enable_signaling() op which can be used to inform a fence supporting
    hw->hw signaling that one or more devices which do not support hw
    signaling are waiting (and therefore it should enable an irq or do
    whatever is necessary in order that the CPU is notified when the
    fence is passed).
v3: Fix locking fail in attach_fence() and get_fence()
v4: Remove tie-in w/ dma-buf..  after discussion w/ danvet and mlankorst
    we decided that we need to be able to attach one fence to N dma-buf's,
    so using the list_head in dma-fence struct would be problematic.
v5: [ Maarten Lankhorst ] Updated for dma-bikeshed-fence and dma-buf-manager.
v6: [ Maarten Lankhorst ] I removed dma_fence_cancel_callback and some comments
    about checking if fence fired or not. This is broken by design.
    waitqueue_active during destruction is now fatal, since the signaller
    should be holding a reference in enable_signalling until it signalled
    the fence. Pass the original dma_fence_cb along, and call __remove_wait
    in the dma_fence_callback handler, so that no cleanup needs to be
    performed.
v7: [ Maarten Lankhorst ] Set cb->func and only enable sw signaling if
    fence wasn't signaled yet, for example for hardware fences that may
    choose to signal blindly.
v8: [ Maarten Lankhorst ] Tons of tiny fixes, moved __dma_fence_init to
    header and fixed include mess. dma-fence.h now includes dma-buf.h
    All members are now initialized, so kmalloc can be used for
    allocating a dma-fence. More documentation added.
v9: Change compiler bitfields to flags, change return type of
    enable_signaling to bool. Rework dma_fence_wait. Added
    dma_fence_is_signaled and dma_fence_wait_timeout.
    s/dma// and change exports to non GPL. Added fence_is_signaled and
    fence_enable_sw_signaling calls, add ability to override default
    wait operation.
v10: remove event_queue, use a custom list, export try_to_wake_up from
    scheduler. Remove fence lock and use a global spinlock instead,
    this should hopefully remove all the locking headaches I was having
    on trying to implement this. enable_signaling is called with this
    lock held.
v11:
    Use atomic ops for flags, lifting the need for some spin_lock_irqsaves.
    However I kept the guarantee that after fence_signal returns, it is
    guaranteed that enable_signaling has either been called to completion,
    or will not be called any more.

    Add contexts and seqno to base fence implementation. This allows you
    to wait for less fences, by testing for seqno + signaled, and then only
    wait on the later fence.

    Add FENCE_TRACE, FENCE_WARN, and FENCE_ERR. This makes debugging easier.
    An CONFIG_DEBUG_FENCE will be added to turn off the FENCE_TRACE
    spam, and another runtime option can turn it off at runtime.
v12:
    Add CONFIG_FENCE_TRACE. Add missing documentation for the fence->context
    and fence->seqno members.
v13:
    Fixup CONFIG_FENCE_TRACE kconfig description.
    Move fence_context_alloc to fence.
    Simplify fence_later.
    Kill priv member to fence_cb.
v14:
    Remove priv argument from fence_add_callback, oops!
v15:
    Remove priv from documentation.
    Explicitly include linux/atomic.h.
v16:
    Add trace events.
    Import changes required by android syncpoints.
v17:
    Use wake_up_state instead of try_to_wake_up. (Colin Cross)
    Fix up commit description for seqno_fence. (Rob Clark)
v18:
    Rename release_fence to fence_release.
    Move to drivers/dma-buf/.
    Rename __fence_is_signaled and __fence_signal to *_locked.
    Rename __fence_init to fence_init.
    Make fence_default_wait return a signed long, and fix wait ops too.

Signed-off-by: Maarten Lankhorst 
Signed-off-by: Thierry Reding  #use smp_mb__before_atomic()
Acked-by: Sumit Semwal 
Acked-by: Daniel Vetter 
Reviewed-by: Rob Clark 
Signed-off-by: Greg Kroah-Hartman

cma: increase CMA_ALIGNMENT upper limit to 12

2014-06-04T23:54:08+00:00

Some systems require a larger maximum PAGE_SIZE order for CMA allocations.
 To accommodate such systems, increase the upper-bound of the
CMA_ALIGNMENT range to 12 (which ends up being 16MB on systems with 4K
pages).

Signed-off-by: Marc Carino 
Cc: Marek Szyprowski 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kobject: Make support for uevent_helper optional.

2014-04-25T19:00:49+00:00

Support for uevent_helper, aka hotplug, is not required on many systems
these days but it can still be enabled via sysfs or sysctl.

Reported-by: Darren Shepherd 
Signed-off-by: Michael Marineau 
Signed-off-by: Greg Kroah-Hartman