Linux kernel enabled more compilation restrictions related to the stack
size, which caused compilation failures in our code. This commit reduces
the allocation size by allocating the required memory dynamically.
Reviewed-by: NHarry Wentland <Harry.Wentland@amd.com>
Reviewed-by: NAric Cyr <Aric.Cyr@amd.com>
Acked-by: NAlex Hung <alex.hung@amd.com>
Signed-off-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[why]
for the case edid change only changed audio format.
driver still need to update stream.
Reviewed-by: NAlvin Lee <Alvin.Lee2@amd.com>
Reviewed-by: NAric Cyr <Aric.Cyr@amd.com>
Acked-by: NAlex Hung <alex.hung@amd.com>
Signed-off-by: NCharlene Liu <Charlene.Liu@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
It changed since dcn30 but the hubbub31 constructor hasn't been
modified to reflect this.

[How]
Update the value in the constructor to 0x6 so we're checking the right
bits for p-state allow.

It worked before by accident, but can falsely assert 0 depending on HW
state transitions. The most frequent of which appears to be when
all pipes turn off during IGT tests.

Cc: Harry Wentland <harry.wentland@amd.com>

Fixes: e7031d82 ("drm/amd/display: Add pstate verification and recovery for DCN31")
Signed-off-by: NNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: NEric Yang <Eric.Yang2@amd.com>
Acked-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

It must check asic whether support smu
before call smu powerplay function, otherwise
it may cause null point on no support smu asic.
Signed-off-by: NStanley.Yang <Stanley.Yang@amd.com>
Reviewed-by: NEvan Quan <evan.quan@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

It is a hardware issue that VCN can't handle a GTT
backing stored TMZ buffer on CHIP_RAVEN series ASIC.

Move such a TMZ buffer to VRAM domain before command
submission as a workaround.

v2:
 - Use patch_cs_in_place callback.

v3:
 - Bail out early if unsecure IBs.
Suggested-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NLang Yu <Lang.Yu@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

If the GPU is passed through to a guest VM, use the PCI
BAR for CPU FB access rather than the physical address of
carve out.  The physical address is not valid in a guest.

v2: Fix HDP handing as suggested by Michel
Reviewed-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NMichel Dänzer <mdaenzer@redhat.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

This post-op should be a pre-op so that we do not pass -1 as the bit
number to test_bit().  The current code will loop downwards from 63 to
-1.  After changing to a pre-op, it loops from 63 to 0.

Fixes: 71c37505 ("drm/amdgpu/gfx: move more common KIQ code to amdgpu_gfx.c")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

If GFX DPM is disbaled, Stable pstate Test in amdgpu_test fails.
Check GFX DPM statue before change clock level

Log:
[   46.595274] [drm] Initialized amdgpu 3.46.0 20150101 for 0000:02:00.0 on minor 0
[   46.599929] fbcon: amdgpudrmfb (fb0) is primary device
[   46.785753] Console: switching to colour frame buffer device 240x67
[   46.811765] amdgpu 0000:02:00.0: [drm] fb0: amdgpudrmfb frame buffer device
[  131.398407] amdgpu 0000:02:00.0: amdgpu: Failed to set performance level!
Signed-off-by: NYifan Zhang <yifan1.zhang@amd.com>
Acked-by: NHuang Rui <ray.huang@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Use amdgpu_bo_free_kernel instead of amdgpu_bo_unref to
perform a proper cleanup of PDB bo.

v2: update subject to be more accurate
Signed-off-by: NGuchun Chen <guchun.chen@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

On GPUs with RAS enabled, below call trace is observed when
suspending or shutting down device. The cause is we have enabled
memory wipe flag for BOs on such GPUs by default, and such BOs
will go to memory wipe by amdgpu_fill_buffer, however, because
ring is off already, it fails to clean up the memory and throw
this error message. So add a suspend/shutdown check before
wipping memory.

[drm:amdgpu_fill_buffer [amdgpu]] *ERROR* Trying to clear memory with ring turned off.

v2: fix coding style issue

Fixes: fc6ea4be ("drm/amdgpu: Wipe all VRAM on free when RAS is enabled")
Signed-off-by: NGuchun Chen <guchun.chen@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Acked-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why&How] Add a dedicated AMDGPU specific ID for use with
newer ASICs that support USB-C output
Signed-off-by: NAurabindo Pillai <aurabindo.pillai@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Merge tag 'amd-drm-next-5.18-2022-03-18' of https://gitlab.freedesktop.org/agd5f/linux into drm-next

amd-drm-next-5.18-2022-03-18:

amdgpu:
- Aldebaran fixes
- SMU 13.0.5 fixes
- DCN 3.1.5 fixes
- DCN 3.1.6 fixes
- Pipe split fixes
- More display FP cleanup
- DP 2.0 UHBR fix
- DC GPU reset fix
- DC deep color ratio fix
- SMU robustness fixes
- Runtime PM fix for APUs
- IGT reload fixes
- SR-IOV fix
- Misc fixes and cleanups

amdkfd:
- CRIU fixes
- SVM fixes

UAPI:
- Properly handle SDMA transfers with CRIU
  Proposed user mode change: https://github.com/checkpoint-restore/criu/pull/1709Signed-off-by: NDave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220318203717.5833-1-alexander.deucher@amd.com

Merge tag 'drm-intel-next-fixes-2022-03-17' of git://anongit.freedesktop.org/drm/drm-intel into drm-next

- Do not re-enable PSR after it was marked as not reliable (Jose)
- Add missing boundary check in vm_access to avoid out-of-bounds access (Mastan)
- Naming fix for HPD short pulse handling for eDP (Jose)
Signed-off-by: NDave Airlie <airlied@redhat.com>
From: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/YjLnofpe5sMHX7Pt@jlahtine-mobl.ger.corp.intel.com

If a error happens and sink_not_reliable is set, PSR should be disabled
for good but that is not happening.
It would be disabled by the function handling the PSR error but then
on the next fastset it would be enabled again in
_intel_psr_post_plane_update().
It would only be disabled for good in the next modeset where has_psr
will be set false.

v2:
- release psr lock before continue

Fixes: 9ce5884e ("drm/i915/display: Only keep PSR enabled if there is active planes")
Reported-by: NKhaled Almahallawy <khaled.almahallawy@intel.com>
Reported-by: NCharlton Lin <charlton.lin@intel.com>
Cc: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Reviewed-by: NJouni Högander <jouni.hogander@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220311185149.110527-2-jose.souza@intel.com
(cherry picked from commit 15f26bdc)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

Commit 13ea6db2 ("drm/i915/edp: Ignore short pulse when panel
powered off") completely broke short pulse handling for eDP as it is
usually generated by sink when it is displaying image and there is
some error or status that source needs to handle.

When power panel is enabled, this state is enough to power aux
transactions and VDD override is disabled, so intel_pps_have_power()
is always returning false causing short pulses to be ignored.

So here better naming this function that intends to check if aux
lines are powered to avoid the endless cycle mentioned in the commit
being fixed and fixing the check for what it is intended.

v2:
- renamed to intel_pps_have_panel_power_or_vdd()
- fixed indentation

Fixes: 13ea6db2 ("drm/i915/edp: Ignore short pulse when panel powered off")
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJosé Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220311185149.110527-1-jose.souza@intel.com
(cherry picked from commit 8f0c1c09)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>

struct drm_display_mode embeds a list head, so overwriting
the full struct with another one will corrupt the list
(if the destination mode is on a list). Use drm_mode_copy()
instead which explicitly preserves the list head of
the destination mode.

Even if we know the destination mode is not on any list
using drm_mode_copy() seems decent as it sets a good
example. Bad examples of not using it might eventually
get copied into code where preserving the list head
actually matters.

Obviously one case not covered here is when the mode
itself is embedded in a larger structure and the whole
structure is copied. But if we are careful when copying
into modes embedded in structures I think we can be a
little more reassured that bogus list heads haven't been
propagated in.

@is_mode_copy@
@@
drm_mode_copy(...)
{
...
}

@depends on !is_mode_copy@
struct drm_display_mode *mode;
expression E, S;
@@
(
- *mode = E
+ drm_mode_copy(mode, &E)
|
- memcpy(mode, E, S)
+ drm_mode_copy(mode, E)
)

@depends on !is_mode_copy@
struct drm_display_mode mode;
expression E;
@@
(
- mode = E
+ drm_mode_copy(&mode, &E)
|
- memcpy(&mode, E, S)
+ drm_mode_copy(&mode, E)
)

@@
struct drm_display_mode *mode;
@@
- &*mode
+ mode

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Reviewed-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

struct drm_display_mode embeds a list head, so overwriting
the full struct with another one will corrupt the list
(if the destination mode is on a list). Use drm_mode_copy()
instead which explicitly preserves the list head of
the destination mode.

Even if we know the destination mode is not on any list
using drm_mode_copy() seems decent as it sets a good
example. Bad examples of not using it might eventually
get copied into code where preserving the list head
actually matters.

Obviously one case not covered here is when the mode
itself is embedded in a larger structure and the whole
structure is copied. But if we are careful when copying
into modes embedded in structures I think we can be a
little more reassured that bogus list heads haven't been
propagated in.

@is_mode_copy@
@@
drm_mode_copy(...)
{
...
}

@depends on !is_mode_copy@
struct drm_display_mode *mode;
expression E, S;
@@
(
- *mode = E
+ drm_mode_copy(mode, &E)
|
- memcpy(mode, E, S)
+ drm_mode_copy(mode, E)
)

@depends on !is_mode_copy@
struct drm_display_mode mode;
expression E;
@@
(
- mode = E
+ drm_mode_copy(&mode, &E)
|
- memcpy(&mode, E, S)
+ drm_mode_copy(&mode, E)
)

@@
struct drm_display_mode *mode;
@@
- &*mode
+ mode

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Remove the boilerplate of declaring a variable and using an if else
statement by using the ternary operator.
Reviewed-by: NJames Zhu <James.Zhu@amd.com>
Signed-off-by: NPaul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

These on stack copies of the modes appear to be pointless.
Just look at the originals directly.

Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Cc: Nikola Cornij <nikola.cornij@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Reviewed-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Smatch complains that the dev_err_ratelimited() is indented one tab more
than the surrounding lines.

	drivers/gpu/drm/amd/amdgpu/../pm/swsmu/smu_cmn.c:174
	__smu_cmn_reg_print_error() warn: inconsistent indenting

It looks like it's not a bug, just that the indenting needs to be cleaned
up.
Reviewed-by: NLuben Tuikov <luben.tuikov@amd.com>
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Various spelling mistakes in comments.
Detected with the help of Coccinelle.
Signed-off-by: NJulia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Various spelling mistakes in comments.
Detected with the help of Coccinelle.
Signed-off-by: NJulia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Various spelling mistakes in comments.
Detected with the help of Coccinelle.
Signed-off-by: NJulia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

MI25 SRIOV guest driver loading failed due to allocated memory overlaps
with firmware reserved area.
Allocate stolen reserved memory for MI25 SRIOV specifically to avoid the
memory overlap.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NYongqiang Sun <yongqiang.sun@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Some ASICs need reserved memory for firmware or other components,
which is not allowed to be used by driver.
amdgpu_gmc_get_reserved_allocation is to handle additional areas.
To avoid any missing calling,
merged amdgpu_gmc_get_reserved_allocation to
amdgpu_gmc_get_vbios_allocations.
Acked-by: NChristian König <christian.koenig@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NYongqiang Sun <yongqiang.sun@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Migrate vram to ram may fail to find the vma if process is exiting
and vma is removed, evict svm bo worker sets prange->svm_bo to NULL
and warn svm_bo ref count != 1 only if migrating vram to ram
successfully.
Signed-off-by: NPhilip Yang <Philip.Yang@amd.com>
Reviewed-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[why]
On Renoir, vcn ring test failed on the second time insmod in the reload
test. After investigation, it proves that vcn only can disable dpg under
dpg unpause mode (dpg unpause mode is default for dec only, dpg pause
mode is for dec/enc).

[how]
unpause dpg in dpg stopping procedure.
Reviewed-by: NJames Zhu <James.Zhu@amd.com>
Signed-off-by: NTianci Yin <tianci.yin@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Only GFX ring, SDMA ring and VCN decode ring support secure submission
at the moment.
Suggested-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NLang Yu <Lang.Yu@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

The reported warnings are as follows:
  1.warning:no-previous-prototype-for-amdgpu_hdp_ras_fini.
  2.warning:no-previous-prototype-for-amdgpu_mmhub_ras_fini.

Amdgpu_hdp_ras_fini and amdgpu_mmhub_ras_fini are unused
in the code, they are the only functions in amdgpu_hdp.c
and amdgpu_mmhub.c. After removing these two functions,
both amdgpu_hdp.c and amdgpu_mmhub.c are empty, so these
two files can be deleted to fix the warning.
Signed-off-by: Nyipechai <YiPeng.Chai@amd.com>
Reviewed-by: NTao Zhou <tao.zhou1@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

    This version brings along following fixes:
    - Added I2C escape to support query exist
    - Functionality to get pipe from stream context
    - debugfs entry fixes
    - Block zstate when more than one plane enabled
    - Update to engine ddc
    - Reading lante status during LT fixes
    - Null point filters
    - [FW Promotion] Release 0.0.108.0
Acked-by: NAgustin Gutierrez <agustin.gutierrez@amd.com>
Signed-off-by: NAric Cyr <aric.cyr@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Reviewed-by: NAric Cyr <Aric.Cyr@amd.com>
Acked-by: NAgustin Gutierrez <agustin.gutierrez@amd.com>
Signed-off-by: NAnthony Koo <Anthony.Koo@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[why]
DCN31 has this in zstate save/restore sequence.
need for non_zstate supported ASIC

[how]
add this PANEL_PWRSEQ_REF_DIV2 to existing panel_cntl_hw_init structure.
Reviewed-by: NNicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: NAgustin Gutierrez <agustin.gutierrez@amd.com>
Signed-off-by: NCharlene Liu <Charlene.Liu@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
Underflow occurred while hubp ret pipe read is idle and the
second pipe is powered up and added. Flickering and underflow
are only observed on Pollock.

[How]
Check the hubp ret pipe read prior to unlock pipes.
Reviewed-by: NHersen Wu <hersenxs.wu@amd.com>
Reviewed-by: NAric Cyr <Aric.Cyr@amd.com>
Acked-by: NAgustin Gutierrez <agustin.gutierrez@amd.com>
Signed-off-by: NBecle Lee <becle.lee@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why & How]
Add null pointer filter for logical integrity.
Reviewed-by: NCharlene Liu <Charlene.Liu@amd.com>
Acked-by: NAgustin Gutierrez <agustin.gutierrez@amd.com>
Signed-off-by: NJing Zhou <Jing.Zhou@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
In dp_get_lane_status_and_lane_adjust(), we call core_link_read_dpcd()
to get lane status but we ignore the return value of the function. If
there is problem with AUX and we eventually can only get partial data
from monitor, we might misuse the data to jude the link training result.
Which could have us trapped in the dc_link_dp_perform_link_training()
since we thought that we can still give a try on another link setting.

[How]
In dp_get_lane_status_and_lane_adjust(), take return value of
core_link_read_dpcd() into account. If we fail to read all requested
data, we treat lanes status as previous one and repeat LT steps again.
Reviewed-by: NWenjing Liu <Wenjing.Liu@amd.com>
Acked-by: NAgustin Gutierrez <agustin.gutierrez@amd.com>
Signed-off-by: NWayne Lin <Wayne.Lin@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
We must support a new type of partial edid return in the future

[How]
Add interface and case hander for partial edid
Reviewed-by: NCharlene Liu <Charlene.Liu@amd.com>
Acked-by: NAgustin Gutierrez <agustin.gutierrez@amd.com>
Signed-off-by: NDale Zhao <dale.zhao@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
Currently Z10 save/restore only covers 1 plane case. If we enter
Z10 with 2 planes enabled, 1 of the 2 planes will not be restored.
causing black screen.

[How]
Disable Zstate when more than 1 plane is enabled. Right now Z9 enable
but Z10 disable is not a supported config, so we disable both.
Reviewed-by: NNicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Reviewed-by: NNevenko Stupar <Nevenko.Stupar@amd.com>
Acked-by: NAgustin Gutierrez <agustin.gutierrez@amd.com>
Signed-off-by: NEric Yang <Eric.Yang2@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
Crash caused by a ddc update failure

[How]
Update engine ddc before release engine.
Reviewed-by: NWyatt Wood <Wyatt.Wood@amd.com>
Reviewed-by: NAric Cyr <Aric.Cyr@amd.com>
Acked-by: NAgustin Gutierrez <agustin.gutierrez@amd.com>
Signed-off-by: NJing Zhou <Jing.Zhou@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why & How]
1. To leverage and simplify the igt tool. Change the value of
retrain when calling preferred training settings.
Now, writing value to link settings triggers link training immediately.

2. Add dc lock when triggering link training in edp_ilr_write()
Reviewed-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: NAgustin Gutierrez <agustin.gutierrez@amd.com>
Signed-off-by: NWayne Lin <Wayne.Lin@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

[Why]
We need a helper function in dc to grab the pipe from the stream
context.

[How]
Add it.
Reviewed-by: NMartin Leung <Martin.Leung@amd.com>
Acked-by: NAgustin Gutierrez <agustin.gutierrez@amd.com>
Signed-off-by: NLeo (Hanghong) Ma <hanghong.ma@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>