Warn if the conditions to enter or exit DC5 are not satisfied such
as support for runtime PM, state of power well, CSR loading etc.

v2: Removed camelcase in functions and variables.

v3: Do some minimal check to assert if CSR program is not loaded.

v4:
1] Used an appropriate function lookup_power_well() to identify power well,
instead of using a magic number which can change in future.
2] Split the conditions further in assert_can_enable_DC5() and added more checks.
3] Removed all WARNs from assert_can_disable_DC5 as they were unnecessary and added two
   new ones.
4] Changed variable names as updated in earlier patches.

v5:
1] Change lookup_power_well function to take an int power well id.
2] Define a new intel_display_power_well_is_enabled helper function to check whether a
   particular power well is enabled.
3] Use CSR-related mutex in assert_csr_loaded function.

v6: Remove use of dc5_enabled variable as it's no longer needed.

v7:
1] Rebase to latest.
2] Move all DC5-related functions from intel_display.c to intel_runtime_pm.c.

v8: After adding dmc ver 1.0 support rebased on top of nightly. (Animesh)

v9: Modified below changes based on review comments from Imre.
- Moved intel_display_power_well_is_enabled() to intel_runtime_pm.c.
- Removed mutex lock from assert_csr_loaded(). (Animesh)

Issue: VIZ-2819
Signed-off-by: NA.Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NSuketu Shah <suketu.j.shah@intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch just implements the basic enable and disable
functions of DC5 state which is needed for both SKL and BXT.

Its important to load respective CSR program before calling
enable, which anyways will happen as CSR program is executed
during boot.

DC5 is a power saving state where hardware dynamically disables
power well 1 and the CDCLK PLL and saves the associated registers.

DC5 can be entered when software allows it, power well 2 is
disabled, and hardware detects that all pipes are disabled
or pipe A is enabled with PSR active.

Its better to configure display engine to have power well 2 disabled before
getting into DC5 enable function. Hence rpm framework will have to
ensure to check status of power well 2 before calling gen9_enable_dc5.

Rather dc5 entry criteria should be decided based on power well 2 status.
If disabled, then call gen9_enable_dc5.

v2: Replace HAS_ with IS_ check as per Daniel's review comments

v3: Cleared the bits dc5/dc6 enable of DC_STATE_EN register
before setting them as per Satheesh's review comments.

v4: call POSTING_READ for every write to a register to ensure that
its written immediately.

v5: Modified as per review comments from Imre.
- Squashed register definitions into this patch.
- Finetuned comments and functions.

v6:
Avoid redundant writes in gen9_set_dc_state_debugmask_memory_up function.

v7:
- Rebase to latest.
- Move all runtime PM functions defined in intel_display.c to
  intel_runtime_pm.c.

v8: Rebased to drm-intel-nightly. (Animesh)

Issue: VIZ-2819
Signed-off-by: NA.Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Add triggers as per expectations mentioned in gen9_enable_dc5
and gen9_disable_dc5 patch.

Also call POSTING_READ for every write to a register to ensure that
its written immediately.

v1: Remove POSTING_READ calls as they've already been added in previous patches.

v2: Rebase to move all runtime pm specific changes to intel_runtime_pm.c file.

Modified as per review comments from Imre:
1] Change variable name 'dc5_allowed' to 'dc5_enabled' to correspond to relevant
   functions.
2] Move the check dc5_enabled in skl_set_power_well() to disable DC5 into
   gen9_disable_DC5 which is a more appropriate place.
3] Convert checks for 'pm.dc5_enabled' and 'pm.suspended' in skl_set_power_well()
   to warnings. However, removing them for now as they'll be included in a future patch
   asserting DC-state entry/exit criteria.
4] Enable DC5, only when CSR firmware is verified to be loaded. Create new structure
   to track 'enabled' and 'deferred' status of DC5.
5] Ensure runtime PM reference is obtained, if CSR is not loaded, to avoid entering
   runtime-suspend and release it when it's loaded.
6] Protect necessary CSR-related code with locks.
7] Move CSR-loading call to runtime PM initialization, as power domains needed to be
   accessed during deferred DC5-enabling, are not initialized earlier.

v3: Rebase to latest.

Modified as per review comments from Imre:
1] Use blocking wait for CSR-loading to finish to enable DC5  for simplicity, instead of
   deferring enabling DC5 until CSR is loaded.
2] Obtain runtime PM reference during CSR-loading initialization itself as deferred DC5-
   enabling is removed and release it at the end of CSR-loading functionality.
3] Revert calling CSR-loading functionality to the beginning of i915 driver-load
   functionality to avoid any delay in loading.
4] Define another variable to track whether CSR-loading failed and use it to avoid enabling
   DC5 if it's true.
5] Define CSR-load-status accessor functions for use later.

v4:
1] Disable DC5 before enabling PG2 instead of after it.
2] DC5 was being mistaken enabled even when CSR-loading timed-out. Fix that.
3] Enable DC5-related functionality using a macro.
4] Remove dc5_enabled tracking variable and its use as it's not needed now.

v5:
1] Mark CSR failed to load where necessary in finish_csr_load function.
2] Use mutex-protected accessor function to check if CSR loaded instead of directly
   accessing the variable.
3] Prefix csr_load_status_get/set function names with intel_.

v6: rebase to latest.
v7: Rebase on top of nightly (Damien)
v8: Squashed the patch from Imre - added csr helper pointers to simplify the code. (Imre)
v9: After adding dmc ver 1.0 support rebased on top of nightly. (Animesh)
v10: Added a enum for different csr states, suggested by Imre. (Animesh)

v11: Based on review comments from Imre, Damien and Daniel following changes done
- enum name chnaged to csr_state (singular form).
- FW_UNINITIALIZED used as zeroth element in enum csr_state.
- Prototype changed for helper function(set/get csr status), using enum csr_state instead of bool.

v12: Based on review comment from Imre, introduced bool fw_loaded local to finish_csr_load() which helps
calling once to set the csr status. The same flag used to fail RPM if find any issue during
firmware loading.

Issue: VIZ-2819
Signed-off-by: NA.Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NSuketu Shah <suketu.j.shah@intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Display Context Save and Restore support is needed for
various SKL Display C states like DC5, DC6.

This implementation is added based on first version of DMC CSR program
that we received from h/w team.

Here we are using request_firmware based design.
Finally this firmware should end up in linux-firmware tree.

For SKL platform its mandatory to ensure that we load this
csr program before enabling DC states like DC5/DC6.

As CSR program gets reset on various conditions, we should ensure
to load it during boot and in future change to be added to load
this system resume sequence too.

v1: Initial relese as RFC patch

v2: Design change as per Daniel, Damien and Shobit's review comments
request firmware method followed.

v3: Some optimization and functional changes.
Pulled register defines into drivers/gpu/drm/i915/i915_reg.h
Used kmemdup to allocate and duplicate firmware content.
Ensured to free allocated buffer.

v4: Modified as per review comments from Satheesh and Daniel
Removed temporary buffer.
Optimized number of writes by replacing I915_WRITE with I915_WRITE64.

v5:
Modified as per review comemnts from Damien.
- Changed name for functions and firmware.
- Introduced HAS_CSR.
- Reverted back previous change and used csr_buf with u8 size.
- Using cpu_to_be64 for endianness change.

Modified as per review comments from Imre.
- Modified registers and macro names to be a bit closer to bspec terminology
and the existing register naming in the driver.
- Early return for non SKL platforms in intel_load_csr_program function.
- Added locking around CSR program load function as it may be called
concurrently during system/runtime resume.
- Releasing the fw before loading the program for consistency
- Handled error path during f/w load.

v6: Modified as per review comments from Imre.
- Corrected out_freecsr sequence.

v7: Modified as per review comments from Imre.
Fail loading fw if fw->size%8!=0.

v8: Rebase to latest.

v9: Rebase on top of -nightly (Damien)

v10: Enabled support for dmc firmware ver 1.0.
According to ver 1.0 in a single binary package all the firmware's that are
required for different stepping's of the product will be stored. The package
contains the css header, followed by the package header and the actual dmc
firmwares. Package header contains the firmware/stepping mapping table and
the corresponding firmware offsets to the individual binaries, within the
package. Each individual program binary contains the header and the payload
sections whose size is specified in the header section. This changes are done
to extract the specific firmaware from the package. (Animesh)

v11: Modified as per review comemnts from Imre.
- Added code comment from bpec for header structure elements.
- Added __packed to avoid structure padding.
- Added helper functions for stepping and substepping info.
- Added code comment for CSR_MAX_FW_SIZE.
- Disabled BXT firmware loading, will be enabled with dmc 1.0 support.
- Changed skl_stepping_info based on bspec, earlier used from config DB.
- Removed duplicate call of cpu_to_be* from intel_csr_load_program function.
- Used cpu_to_be32 instead of cpu_to_be64 as firmware binary in dword aligned.
- Added sanity check for header length.
- Added sanity check for mmio address got from firmware binary.
- kmalloc done separately for dmc header and dmc firmware. (Animesh)

v12: Modified as per review comemnts from Imre.
- Corrected the typo error in skl stepping info structure.
- Added out-of-bound access for skl_stepping_info.
- Sanity check for mmio address modified.
- Sanity check added for stepping and substeppig.
- Modified the intel_dmc_info structure, cache only the required header info. (Animesh)

v13: clarify firmware load error message.
The reason for a firmware loading failure can be obscure if the driver
is built-in. Provide an explanation to the user about the likely reason for
the failure and how to resolve it. (Imre)

v14: Suggested by Jani.
- fix s/I915/CONFIG_DRM_I915/ typo
- add fw_path to the firmware object instead of using a static ptr (Jani)

v15:
1) Changed the firmware name as dmc_gen9.bin, everytime for a new firmware version a symbolic link
with same name will help not to build kernel again.
2) Changes done as per review comments from Imre.
- Error check removed for intel_csr_ucode_init.
- Moved csr-specific data structure to intel_csr.h and optimization done on structure definition.
- fw->data used directly for parsing the header info & memory allocation
only done separately for payload. (Animesh)

v16:
- No need for out_regs label in i915_driver_load(), so removed it.
- Changed the firmware name as skl_dmc_ver1.bin, followed naming convention <platform>_dmc_<api-version>.bin (Animesh)

Issue: VIZ-2569
Signed-off-by: NA.Sunil Kamath <sunil.kamath@intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NAnimesh Manna <animesh.manna@intel.com>
Signed-off-by: NImre Deak <imre.deak@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

i915_needs_cmd_parser already checks that for us.
Suggested-by: NMika Kuoppala <mika.kuoppala@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Signed-off-by: NNick Hoath <nicholas.hoath@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch enables skylake sprite plane display scaling using shared
scalers atomic desgin.

v2:
-use single copy of scaler limits (Matt)

v3:
-detaching scalers moved to crtc commit path (Matt)

v4:
-changes to align with updated scaler structures (Matt, me)
-keep sprite src rect in 16.16 format (Matt, Daniel)

v5:
-rebased on top of 90/270 rotation changes (me)
-Refactored skl_update_plane to reduce its size (Daniel)
 It is a step towards having a single function covering all planes.
Signed-off-by: NChandra Konduru <chandra.konduru@intel.com>
Reviewed-by: NMatt Roper <matthew.d.roper@intel.com>
Testcase: igt/kms_plane_scaling
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This patch enables skylake primary plane scaling using shared
scalers atomic desgin.

v2:
-use single copy of scaler limits (Matt)

v3:
-move detach_scalers to crtc commit path (Matt)
-use values in plane_state->src as regular integers (me)

v4:
-changes to align with updated scaler structures (Matt, me)
-keep plane src rect in 16.16 format (Matt, Daniel)

v5:
-Rebased on top of 90/270 rotation changes (me)
-Fixed an issue introduced by 90/270 changes where plane programming
 is using drm_plane->state rect instead of intel_plane->state rect.
 This change also required for scaling to work properly. (me)
-With 90/270, updated limits to cover both portrait and landscape usages (me)
-Refactored skylake_update_primary_plane to reduce its size (Daniel)
 Added helper functions for refactoring are comprehended enough to be
 used for skylake_update_plane (for sprite) too. One stop towards
 having single function for all planes.

v6:
-Added fixme note when checking plane_state->src width in update_plane (Daniel)
-Release lock when failing to colorkey request with active scaler (Daniel)
Signed-off-by: NChandra Konduru <chandra.konduru@intel.com>
Reviewed-by: matthew.d.roper@intel.com
Reviewed-by: sonika.jindal@intel.com (v5)
Testcase: igt/kms_plane_scaling
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Merge tag 'drm-intel-next-2015-04-23-fixed' of git://anongit.freedesktop.org/drm-intel into drm-next

drm-intel-next-2015-04-23:
- dither support for ns2501 dvo (Thomas Richter)
- some polish for the gtt code and fixes to finally enable the cmd parser on hsw
- first pile of bxt stage 1 enabling (too many different people to list ...)
- more psr fixes from Rodrigo
- skl rotation support from Chandra
- more atomic work from Ander and Matt
- pile of cleanups and micro-ops for execlist from Chris
drm-intel-next-2015-04-10:
- cdclk handling cleanup and fixes from Ville
- more prep patches for olr removal from John Harrison
- gmbus pin naming rework from Jani (prep for bxt)
- remove ->new_config from Ander (more atomic conversion work)
- rps (boost) tuning and unification with byt/bsw from Chris
- cmd parser batch bool tuning from Chris
- gen8 dynamic pte allocation (Michel Thierry, based on work from Ben Widawsky)
- execlist tuning (not yet all of it) from Chris
- add drm_plane_from_index (Chandra)
- various small things all over

* tag 'drm-intel-next-2015-04-23-fixed' of git://anongit.freedesktop.org/drm-intel: (204 commits)
  drm/i915/gtt: Allocate va range only if vma is not bound
  drm/i915: Enable cmd parser to do secure batch promotion for aliasing ppgtt
  drm/i915: fix intel_prepare_ddi
  drm/i915: factor out ddi_get_encoder_port
  drm/i915/hdmi: check port in ibx_infoframe_enabled
  drm/i915/hdmi: fix vlv infoframe port check
  drm/i915: Silence compiler warning in dvo
  drm/i915: Update DRIVER_DATE to 20150423
  drm/i915: Enable dithering on NatSemi DVO2501 for Fujitsu S6010
  rm/i915: Move i915_get_ggtt_vma_pages into ggtt_bind_vma
  drm/i915: Don't try to outsmart gcc in i915_gem_gtt.c
  drm/i915: Unduplicate i915_ggtt_unbind/bind_vma
  drm/i915: Move ppgtt_bind/unbind around
  drm/i915: move i915_gem_restore_gtt_mappings around
  drm/i915: Fix up the vma aliasing ppgtt binding
  drm/i915: Remove misleading comment around bind_to_vm
  drm/i915: Don't use atomics for pg_dirty_rings
  drm/i915: Don't look at pg_dirty_rings for aliasing ppgtt
  drm/i915/skl: Support Y tiling in MMIO flips
  drm/i915: Fixup kerneldoc for struct intel_context
  ...

Conflicts:
	drivers/gpu/drm/i915/i915_drv.c

Completely different approach:  Instead of encoding each and every
framebuffer update as spice operation simply update the shadow
framebuffer and maintain a dirty rectangle.  Also schedule a worker
to push an update for the dirty rectangle as spice operation.  Usually
a bunch of dirty rectangle updates are collected before the worker
actually runs.

What changes:  Updates get batched now.  Instead of sending tons of
small updates a few large ones are sent.  When the same region is
updated multiple times within a short timeframe (scrolling multiple
lines for example) we send a single update only.  Spice server has an
easier job now:  The dependency tree for display operations which spice
server maintains for lazy rendering is alot smaller now.  Spice server's
image compression probably works better too with the larger image blits.

Net effect:  framebuffer console @ qxldrmfb is an order of magnitude
faster now.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

misc drm core patches.

* tag 'topic/drm-misc-2015-05-06' of git://anongit.freedesktop.org/drm-intel:
  drm: simplify master cleanup
  drm: simplify authentication management
  drm: drop unused 'magicfree' list
  drm: fix a memleak on mutex failure path
  drm/atomic-helper: Really recover pre-atomic plane/cursor behavior
  drm/qxl: Fix qxl_noop_get_vblank_counter()
  drm: Zero out invalid vblank timestamp in drm_update_vblank_count. (v2)
  drm: Prevent invalid use of vblank_disable_immediate. (v2)
  drm/vblank: Fixup and document timestamp update/read barriers
  DRM: Don't re-poll connector for disconnect
  drm: Fix for DP CTS test 4.2.2.5 - I2C DEFER handling
  drm: Fix the 'native defer' message in drm_dp_i2c_do_msg()
  drm/atomic-helper: Don't call atomic_update_plane when it stays off

In drm_master_destroy() we _free_ the master object. There is no reason to
hold any locks while dropping its static members, nor do we have to reset
it to 0.

Furthermore, kfree() already does NULL checks, so call it directly on
master->unique and drop the redundant reset-code.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The magic auth tokens we have are a simple map from cyclic IDs to drm_file
objects. Remove all the old bulk of code and replace it with a simple,
direct IDR.

The previous behavior is kept. Especially calling authmagic multiple times
on the same magic results in EINVAL except on the first call. The only
difference in behavior is that we never allocate IDs multiple times as
long as a client has its FD open.

v2:
 - Fix return code of GetMagic()
 - Use non-cyclic IDR allocator
 - fix off-by-one in "magic > INT_MAX" sanity check

v3:
 - drop redundant "magic > INT_MAX" check
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This list is write-only. It's never used for read-access, so no reason to
keep it around. Drop it!
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Need to free just allocated ctx allocation if we cannot
get our config mutex.

This one has been flagged by kbuild bot all the way back in August,
but somehow nobody picked it up:
https://lists.01.org/pipermail/kbuild/2014-August/001691.html

In addition there is another failure path that leaks the same
ctx reference that is fixed.

Found with smatch.
Signed-off-by: NOleg Drokin <green@linuxhacker.ru>
CC: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

I've fumbled this in

commit f02ad907
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Jan 22 16:36:23 2015 +0100

    drm/atomic-helpers: Recover full cursor plane behaviour

and accidentally put the assignment for legacy_cursor_upate after the
atomic commit, where it is pretty useless.
Reported-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

This breaks under the vblank timestamp cleanup patch
by Daniel Vetter. Also it is pointless to return anything
but zero (or any other constant) if the function doesn't
actually query a hw vblank counter. The bogus return of
the current drm vblank counter via direct readout or via
drm_vblank_count() is found in many of the new kms drivers,
but it does exactly nothing different from returning any
arbitrary constant - it's a no operation.

Let's simply return 0 - Easy and fast.
Signed-off-by: NMario Kleiner <mario.kleiner.de@gmail.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since commit 844b03f2 we make
sure that after vblank irq off, we return the last valid
(vblank count, vblank timestamp) pair to clients, e.g., during
modesets, which is good.

An overlooked side effect of that commit for kms drivers without
support for precise vblank timestamping is that at vblank irq
enable, when we update the vblank counter from the hw counter, we
can't update the corresponding vblank timestamp, so now we have a
totally mismatched timestamp for the new count to confuse clients.

Restore old client visible behaviour from before Linux 3.18, but
zero out the timestamp at vblank counter update (instead of disable
as in original implementation) if we can't generate a meaningful
timestamp immediately for the new vblank counter. This will fix
this regression, so callers know they need to retry again later
if they need a valid timestamp, but at the same time preserves
the improvements made in the commit mentioned above.

v2: Rebased on top of Daniel Vetter's fixup and documentation
    patch for timestamp updates. Drop request for stable kernel
    backport as this would be more difficult, unless the original
    patch would get applied to stable kernels.
Signed-off-by: NMario Kleiner <mario.kleiner.de@gmail.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For a kms driver to support immediate disable of vblank
irq's reliably without introducing off by one errors or
other mayhem for clients, it must not only support a
hardware vblank counter query, but also high precision
vblank timestamping, so vblank count and timestamp can be
instantaneously reinitialzed to valid values. Additionally
the exposed hardware counter must behave as if it is
incrementing at leading edge of vblank to avoid off by
one errors during reinitialization of the counter while
the display happens to be inside or close to vblank.

Check during drm_vblank_init that a driver which claims to
be capable of vblank_disable_immediate at least supports
high precision timestamping and prevent use of instant
disable if that isn't present as a minimum requirement.

v2: Changed from DRM_ERROR to DRM_INFO and made message
    more clear, as suggested by Michel Dänzer.
Signed-off-by: NMario Kleiner <mario.kleiner.de@gmail.com>
Reviewed-by: NMichel Dänzer <michel.daenzer@amd.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This was a bit too much cargo-culted, so lets make it solid:
- vblank->count doesn't need to be an atomic, writes are always done
  under the protection of dev->vblank_time_lock. Switch to an unsigned
  long instead and update comments. Note that atomic_read is just a
  normal read of a volatile variable, so no need to audit all the
  read-side access specifically.

- The barriers for the vblank counter seqlock weren't complete: The
  read-side was missing the first barrier between the counter read and
  the timestamp read, it only had a barrier between the ts and the
  counter read. We need both.

- Barriers weren't properly documented. Since barriers only work if
  you have them on boths sides of the transaction it's prudent to
  reference where the other side is. To avoid duplicating the
  write-side comment 3 times extract a little store_vblank() helper.
  In that helper also assert that we do indeed hold
  dev->vblank_time_lock, since in some cases the lock is acquired a
  few functions up in the callchain.

Spotted while reviewing a patch from Chris Wilson to add a fastpath to
the vblank_wait ioctl.

v2: Add comment to better explain how store_vblank works, suggested by
Chris.

v3: Peter noticed that as-is the 2nd smp_wmb is redundant with the
implicit barrier in the spin_unlock. But that can only be proven by
auditing all callers and my point in extracting this little helper was
to localize all the locking into just one place. Hence I think that
additional optimization is too risky.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mario Kleiner <mario.kleiner.de@gmail.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Michel Dänzer <michel@daenzer.net>
Cc: Peter Hurley <peter@hurleysoftware.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-and-tested-by: NMario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Pull in patches Jani applied while I was on vacation.
Signed-off-by: NDaniel Vetter <daniel.vetter@intel.com>

Pull ext4 fixes from Ted Ts'o:
 "Some miscellaneous bug fixes and some final on-disk and ABI changes
  for ext4 encryption which provide better security and performance"

* tag 'for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix growing of tiny filesystems
  ext4: move check under lock scope to close a race.
  ext4: fix data corruption caused by unwritten and delayed extents
  ext4 crypto: remove duplicated encryption mode definitions
  ext4 crypto: do not select from EXT4_FS_ENCRYPTION
  ext4 crypto: add padding to filenames before encrypting
  ext4 crypto: simplify and speed up filename encryption

Pull drm fixes from Dave Airlie:
 "One intel fix, one rockchip fix, and a bunch of radeon fixes for some
  regressions from audio rework and vm stability"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/i915/chv: Implement WaDisableShadowRegForCpd
  drm/radeon: fix userptr return value checking (v2)
  drm/radeon: check new address before removing old one
  drm/radeon: reset BOs address after clearing it.
  drm/radeon: fix lockup when BOs aren't part of the VM on release
  drm/radeon: add SI DPM quirk for Sapphire R9 270 Dual-X 2G GDDR5
  drm/radeon: adjust pll when audio is not enabled
  drm/radeon: only enable audio streams if the monitor supports it
  drm/radeon: only mark audio as connected if the monitor supports it (v3)
  drm/radeon/audio: don't enable packets until the end
  drm/radeon: drop dce6_dp_enable
  drm/radeon: fix ordering of AVI packet setup
  drm/radeon: Use drm_calloc_ab for CS relocs
  drm/rockchip: fix error check when getting irq
  MAINTAINERS: add entry for Rockchip drm drivers

Just a single intel fix
* tag 'drm-intel-fixes-2015-04-30' of git://anongit.freedesktop.org/drm-intel:
  drm/i915/chv: Implement WaDisableShadowRegForCpd

one fix and maintainers update
* 'drm-next0420' of https://github.com/markyzq/kernel-drm-rockchip:
  drm/rockchip: fix error check when getting irq
  MAINTAINERS: add entry for Rockchip drm drivers

Pull SCSI fixes from James Bottomley:
 "This is three logical fixes (as 5 patches).

  The 3ware class of drivers were causing an oops with multiqueue by
  tearing down the command mappings after completing the command (where
  the variables in the command used to tear down the mapping were
  no-longer valid).  There's also a fix for the qnap iscsi target which
  was choking on us sending it commands that were too long and a fix for
  the reworked aha1542 allocating GFP_KERNEL under a lock"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  3w-9xxx: fix command completion race
  3w-xxxx: fix command completion race
  3w-sas: fix command completion race
  aha1542: Allocate memory before taking a lock
  SCSI: add 1024 max sectors black list flag

Pull slave dmaengine fixes from Vinod Koul:
 "Here are the fixes in dmaengine subsystem for rc2:

   - privatecnt fix for slave dma request API by Christopher

   - warn fix for PM ifdef in usb-dmac by Geert

   - fix hardware dependency for xgene by Jean"

* 'next' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: increment privatecnt when using dma_get_any_slave_channel
  dmaengine: xgene: Set hardware dependency
  dmaengine: usb-dmac: Protect PM-only functions to kill warning

Pull powerpc fixes from Michael Ellerman:
 - build fix for SMP=n in book3s_xics.c
 - fix for Daniel's pci_controller_ops on powernv.
 - revert the TM syscall abort patch for now.
 - CPU affinity fix from Nathan.
 - two EEH fixes from Gavin.
 - fix for CR corruption from Sam.
 - selftest build fix.

* tag 'powerpc-4.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
  powerpc/powernv: Restore non-volatile CRs after nap
  powerpc/eeh: Delay probing EEH device during hotplug
  powerpc/eeh: Fix race condition in pcibios_set_pcie_reset_state()
  powerpc/pseries: Correct cpu affinity for dlpar added cpus
  selftests/powerpc: Fix the pmu install rule
  Revert "powerpc/tm: Abort syscalls in active transactions"
  powerpc/powernv: Fix early pci_controller_ops loading.
  powerpc/kvm: Fix SMP=n build error in book3s_xics.c

The estimate of necessary transaction credits in ext4_flex_group_add()
is too pessimistic. It reserves credit for sb, resize inode, and resize
inode dindirect block for each group added in a flex group although they
are always the same block and thus it is enough to account them only
once. Also the number of modified GDT block is overestimated since we
fit EXT4_DESC_PER_BLOCK(sb) descriptors in one block.

Make the estimation more precise. That reduces number of requested
credits enough that we can grow 20 MB filesystem (which has 1 MB
journal, 79 reserved GDT blocks, and flex group size 16 by default).
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>

fallocate() checks that the file is extent-based and returns
EOPNOTSUPP in case is not. Other tasks can convert from and to
indirect and extent so it's safe to check only after grabbing
the inode mutex.
Signed-off-by: NDavide Italiano <dccitaliano@gmail.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

Currently it is possible to lose whole file system block worth of data
when we hit the specific interaction with unwritten and delayed extents
in status extent tree.

The problem is that when we insert delayed extent into extent status
tree the only way to get rid of it is when we write out delayed buffer.
However there is a limitation in the extent status tree implementation
so that when inserting unwritten extent should there be even a single
delayed block the whole unwritten extent would be marked as delayed.

At this point, there is no way to get rid of the delayed extents,
because there are no delayed buffers to write out. So when a we write
into said unwritten extent we will convert it to written, but it still
remains delayed.

When we try to write into that block later ext4_da_map_blocks() will set
the buffer new and delayed and map it to invalid block which causes
the rest of the block to be zeroed loosing already written data.

For now we can fix this by simply not allowing to set delayed status on
written extent in the extent status tree. Also add WARN_ON() to make
sure that we notice if this happens in the future.

This problem can be easily reproduced by running the following xfs_io.

xfs_io -f -c "pwrite -S 0xaa 4096 2048" \
          -c "falloc 0 131072" \
          -c "pwrite -S 0xbb 65536 2048" \
          -c "fsync" /mnt/test/fff

echo 3 > /proc/sys/vm/drop_caches
xfs_io -c "pwrite -S 0xdd 67584 2048" /mnt/test/fff

This can be theoretically also reproduced by at random by running fsx,
but it's not very reliable, though on machines with bigger page size
(like ppc) this can be seen more often (especially xfstest generic/127)
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

This patch removes duplicated encryption modes which were already in
ext4.h. They were duplicated from commit 3edc18d8 and commit f542fb.

Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Michael Halcrow <mhalcrow@google.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: NChanho Park <chanho61.park@samsung.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

This patch adds a tristate EXT4_ENCRYPTION to do the selections
for EXT4_FS_ENCRYPTION because selecting from a bool causes all
the selected options to be built-in, even if EXT4 itself is a
module.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Pull networking fixes from David Miller:

 1) Receive packet length needs to be adjust by 2 on RX to accomodate
    the two padding bytes in altera_tse driver.  From Vlastimil Setka.

 2) If rx frame is dropped due to out of memory in macb driver, we leave
    the receive ring descriptors in an undefined state.  From Punnaiah
    Choudary Kalluri

 3) Some netlink subsystems erroneously signal NLM_F_MULTI.  That is
    only for dumps.  Fix from Nicolas Dichtel.

 4) Fix mis-use of raw rt->rt_pmtu value in ipv4, one must always go via
    the ipv4_mtu() helper.  From Herbert Xu.

 5) Fix null deref in bridge netfilter, and miscalculated lengths in
    jump/goto nf_tables verdicts.  From Florian Westphal.

 6) Unhash ping sockets properly.

 7) Software implementation of BPF divide did 64/32 rather than 64/64
    bit divide.  The JITs got it right.  Fix from Alexei Starovoitov.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (30 commits)
  ipv4: Missing sk_nulls_node_init() in ping_unhash().
  net: fec: Fix RGMII-ID mode
  net/mlx4_en: Schedule napi when RX buffers allocation fails
  netxen_nic: use spin_[un]lock_bh around tx_clean_lock
  net/mlx4_core: Fix unaligned accesses
  mlx4_en: Use correct loop cursor in error path.
  cxgb4: Fix MC1 memory offset calculation
  bnx2x: Delay during kdump load
  net: Fix Kernel Panic in bonding driver debugfs file: rlb_hash_table
  net: dsa: Fix scope of eeprom-length property
  net: macb: Fix race condition in driver when Rx frame is dropped
  hv_netvsc: Fix a bug in netvsc_start_xmit()
  altera_tse: Correct rx packet length
  mlx4: Fix tx ring affinity_mask creation
  tipc: fix problem with parallel link synchronization mechanism
  tipc: remove wrong use of NLM_F_MULTI
  bridge/nl: remove wrong use of NLM_F_MULTI
  bridge/mdb: remove wrong use of NLM_F_MULTI
  net: sched: act_connmark: don't zap skb->nfct
  trivial: net: systemport: bcmsysport.h: fix 0x0x prefix
  ...

Here the "other side" refers to the guest or host.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With my job change kernel work will be "own time"; I'm keeping lguest
and modules (and the virtio standards work), but virtio kernel has to
go.

This makes it clear that Michael is in charge.  He's good, but having
me watch over his shoulder won't help.

Good luck Michael!
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull Ceph RBD fix from Sage Weil.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: end I/O the entire obj_request on error

If we don't do that, then the poison value is left in the ->pprev
backlink.

This can cause crashes if we do a disconnect, followed by a connect().
Tested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Reported-by: NWen Xu <hotdog3645@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we end I/O struct request with error, we need to pass
obj_request->length as @nr_bytes so that the entire obj_request worth
of bytes is completed.  Otherwise block layer ends up confused and we
trip on

    rbd_assert(more ^ (which == img_request->obj_request_count));

in rbd_img_obj_callback() due to more being true no matter what.  We
already do it in most cases but we are missing some, in particular
those where we don't even get a chance to submit any obj_requests, due
to an early -ENOMEM for example.

A number of obj_request->xferred assignments seem to be redundant but
I haven't touched any of obj_request->xferred stuff to keep this small
and isolated.

Cc: Alex Elder <elder@linaro.org>
Cc: stable@vger.kernel.org # 3.10+
Reported-by: NShawn Edwards <lesser.evil@gmail.com>
Reviewed-by: NSage Weil <sage@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>