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  1. 07 10月, 2017 2 次提交
  3. 05 10月, 2017 1 次提交
    • C
      drm/i915/execlists: Preemption! · beecec90
      由 Chris Wilson 提交于 
      When we write to ELSP, it triggers a context preemption at the earliest
arbitration point (3DPRIMITIVE, some PIPECONTROLs, a few other
operations and the explicit MI_ARB_CHECK). If this is to the same
context, it triggers a LITE_RESTORE where the RING_TAIL is merely
updated (used currently to chain requests from the same context
together, avoiding bubbles). However, if it is to a different context, a
full context-switch is performed and it will start to execute the new
context saving the image of the old for later execution.

Previously we avoided preemption by only submitting a new context when
the old was idle. But now we wish embrace it, and if the new request has
a higher priority than the currently executing request, we write to the
ELSP regardless, thus triggering preemption, but we tell the GPU to
switch to our special preemption context (not the target). In the
context-switch interrupt handler, we know that the previous contexts
have finished execution and so can unwind all the incomplete requests
and compute the new highest priority request to execute.

It would be feasible to avoid the switch-to-idle intermediate by
programming the ELSP with the target context. The difficulty is in
tracking which request that should be whilst maintaining the dependency
change, the error comes in with coalesced requests. As we only track the
most recent request and its priority, we may run into the issue of being
tricked in preempting a high priority request that was followed by a
low priority request from the same context (e.g. for PI); worse still
that earlier request may be our own dependency and the order then broken
by preemption. By injecting the switch-to-idle and then recomputing the
priority queue, we avoid the issue with tracking in-flight coalesced
requests. Having tried the preempt-to-busy approach, and failed to find
a way around the coalesced priority issue, Michal's original proposal to
inject an idle context (based on handling GuC preemption) succeeds.

The current heuristic for deciding when to preempt are only if the new
request is of higher priority, and has the privileged priority of
greater than 0. Note that the scheduler remains unfair!

v2: Disable for gen8 (bdw/bsw) as we need additional w/a for GPGPU.
Since, the feature is now conditional and not always available when we
have a scheduler, make it known via the HAS_SCHEDULER GETPARAM (now a
capability mask).
v3: Stylistic tweaks.
v4: Appease Joonas with a snippet of kerneldoc, only to fuel to fire of
the preempt vs preempting debate.
Suggested-by: NMichal Winiarski <michal.winiarski@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.a.wang@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171003203453.15692-8-chris@chris-wilson.co.uk
      beecec90
  5. 04 10月, 2017 3 次提交
  7. 03 10月, 2017 1 次提交
  9. 22 9月, 2017 1 次提交
  11. 20 9月, 2017 1 次提交
  13. 15 9月, 2017 1 次提交
  15. 07 9月, 2017 3 次提交
  17. 01 9月, 2017 2 次提交
  19. 22 8月, 2017 1 次提交
  21. 27 7月, 2017 1 次提交
    • C
      drm/i915: Disable per-engine reset for Broxton · 2b49e721
      由 Chris Wilson 提交于 
      Triggering a GPU reset for one engine affects another, notably
corrupting the context status buffer (CSB) effectively losing track of
inflight requests.

Adding a few printks:
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index ad41836fa5e5..a969456bc0fa 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1953,6 +1953,7 @@ int i915_reset_engine(struct intel_engine_cs *engine)
                goto out;
        }

+       pr_err("Resetting %s\n", engine->name);
        ret = intel_gpu_reset(engine->i915, intel_engine_flag(engine));
        if (ret) {
                /* If we fail here, we expect to fallback to a global reset */
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 716e5c9ea222..a72bc35d0870 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -355,6 +355,7 @@ static void execlists_submit_ports(struct intel_engine_cs *engine)
                                execlists_context_status_change(rq, INTEL_CONTEXT_SCHEDULE_IN);
                        port_set(&port[n], port_pack(rq, count));
                        desc = execlists_update_context(rq);
+                       pr_err("%s: in (rq=%x) ctx=%d\n", engine->name, rq->global_seqno, upper_32_bits(desc));
                        GEM_DEBUG_EXEC(port[n].context_id = upper_32_bits(desc));
                } else {
                        GEM_BUG_ON(!n);
@@ -594,9 +595,23 @@ static void intel_lrc_irq_handler(unsigned long data)
                        if (!(status & GEN8_CTX_STATUS_COMPLETED_MASK))
                                continue;

+                       pr_err("%s: out CSB (%x head=%d, tail=%d), ctx=%d, rq=%d\n",
+                                       engine->name,
+                                       readl(csb_mmio),
+                                       head, tail,
+                                       readl(buf+2*head+1),
+                                       port->context_id);
+
                        /* Check the context/desc id for this event matches */
-                       GEM_DEBUG_BUG_ON(readl(buf + 2 * head + 1) !=
-                                        port->context_id);
+                       if (readl(buf + 2 * head + 1) != port->context_id) {
+                               pr_err("%s: BUG CSB (%x head=%d, tail=%d), ctx=%d, rq=%d\n",
+                                               engine->name,
+                                               readl(csb_mmio),
+                                               head, tail,
+                                               readl(buf+2*head+1),
+                                               port->context_id);
+                               BUG();
+                       }

                        rq = port_unpack(port, &count);
                        GEM_BUG_ON(count == 0);

Results in:

[ 6423.006602] Resetting rcs0
[ 6423.009080] rcs0: in (rq=fffffe70) ctx=1
[ 6423.009216] rcs0: in (rq=fffffe6f) ctx=3
[ 6423.009542] rcs0: out CSB (2 head=1, tail=2), ctx=3, rq=3
[ 6423.009619] Resetting bcs0
[ 6423.009980] rcs0: BUG CSB (0 head=1, tail=2), ctx=0, rq=3

Note that this bug may be affect all machines and not just Broxton,
Broxton is just the first machine on which I have confirmed this bug.

Fixes: 142bc7d9 ("drm/i915: Modify error handler for per engine hang recovery")
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Acked-by: NMichel Thierry <michel.thierry@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170721123238.16428-13-chris@chris-wilson.co.ukSigned-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      2b49e721
  23. 07 7月, 2017 1 次提交
  25. 21 6月, 2017 1 次提交
    • M
      drm/i915: Modify error handler for per engine hang recovery · 142bc7d9
      由 Michel Thierry 提交于 
      This is a preparatory patch which modifies error handler to do per engine
hang recovery. The actual patch which implements this sequence follows
later in the series. The aim is to prepare existing recovery function to
adapt to this new function where applicable (which fails at this point
because core implementation is lacking) and continue recovery using legacy
full gpu reset.

A helper function is also added to query the availability of engine
reset. A subsequent patch will add the capability to query which type
of reset is present (engine -> full -> no-reset) via the get-param
ioctl.

It has been decided that the error events that are used to notify user of
reset will only be sent in case if full chip reset. In case of just
single (or multiple) engine resets, userspace won't be notified by these
events.

Note that this implementation of engine reset is for i915 directly
submitting to the ELSP, where the driver manages the hang detection,
recovery and resubmission. With GuC submission these tasks are shared
between driver and firmware; i915 will still responsible for detecting a
hang, and when it does it will have to request GuC to reset that Engine and
remind the firmware about the outstanding submissions. This will be
added in different patch.

v2: rebase, advertise engine reset availability in platform definition,
add note about GuC submission.
v3: s/*engine_reset*/*reset_engine*/. (Chris)
Handle reset as 2 level resets, by first going to engine only and fall
backing to full/chip reset as needed, i.e. reset_engine will need the
struct_mutex.
v4: Pass the engine mask to i915_reset. (Chris)
v5: Rebase, update selftests.
v6: Rebase, prepare for mutex-less reset engine.
v7: Pass reset_engine mask as a function parameter, and iterate over the
engine mask for reset_engine. (Chris)
v8: Use i915.reset >=2 in has_reset_engine; remove redundant reset
logging; add a reset-engine-in-progress flag to prevent concurrent
resets, and avoid dual purposing of reset-backoff. (Chris)
v9: Support reset of different engines in parallel (Chris)
v10: Handle reset-engine flag locking better (Chris)
v11: Squash in reporting of per-engine-reset availability.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Signed-off-by: NIan Lister <ian.lister@intel.com>
Signed-off-by: NTomas Elf <tomas.elf@intel.com>
Signed-off-by: NArun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: NMichel Thierry <michel.thierry@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170615201828.23144-4-michel.thierry@intel.comReviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170620095751.13127-5-chris@chris-wilson.co.uk
      142bc7d9
  27. 13 6月, 2017 1 次提交
  29. 10 6月, 2017 5 次提交
  31. 09 6月, 2017 2 次提交
  33. 07 6月, 2017 6 次提交
  35. 30 5月, 2017 1 次提交
  37. 28 4月, 2017 1 次提交
    • J
      drm/i915: Eliminate HAS_HW_CONTEXTS · f2e4d76e
      由 Joonas Lahtinen 提交于 
      HAS_HW_CONTEXTS is misleading condition for GPU reset and CCID,
replace it with Gen specific (to be updated in next patches).

HAS_HW_CONTEXTS in i915_l3_write is bogus because each HAS_L3_DPF
match also has .has_hw_contexts = 1 set.

This leads to us being able to get rid of the property completely.

v2:
- Keep the checks at Gen6 for no functional change (Ville)
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      f2e4d76e
  39. 29 3月, 2017 1 次提交
  41. 27 3月, 2017 1 次提交
  43. 14 2月, 2017 1 次提交
    • C
      drm/i915: Provide a hook for selftests · 953c7f82
      由 Chris Wilson 提交于 
      Some pieces of code are independent of hardware but are very tricky to
exercise through the normal userspace ABI or via debugfs hooks. Being
able to create mock unit tests and execute them through CI is vital.
Start by adding a central point where we can execute unit tests and
a parameter to enable them. This is disabled by default as the
expectation is that these tests will occasionally explode.

To facilitate integration with igt, any parameter beginning with
i915.igt__ is interpreted as a subtest executable independently via
igt/drv_selftest.

Two classes of selftests are recognised: mock unit tests and integration
tests. Mock unit tests are run as soon as the module is loaded, before
the device is probed. At that point there is no driver instantiated and
all hw interactions must be "mocked". This is very useful for writing
universal tests to exercise code not typically run on a broad range of
architectures. Alternatively, you can hook into the live selftests and
run when the device has been instantiated - hw interactions are real.

v2: Add a macro for compiling conditional code for mock objects inside
real objects.
v3: Differentiate between mock unit tests and late integration test.
v4: List the tests in natural order, use igt to sort after modparam.
v5: s/late/live/
v6: s/unsigned long/unsigned int/
v7: Use igt_ prefixes for long helpers.
v8: Deobfuscate macros overriding functions, stop using -I$(src)
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-1-chris@chris-wilson.co.uk
      953c7f82
  45. 30 1月, 2017 1 次提交
  47. 05 1月, 2017 1 次提交
    • P
      drm/i915: actually drive the BDW reserved IDs · 98b2f01c
      由 Paulo Zanoni 提交于 
      Back in 2014, commit fb7023e0 ("drm/i915: BDW: Adding Reserved PCI
IDs.") added the reserved PCI IDs in order to try to make sure we had
working drivers in case we ever released products using these IDs
(since we had instances of this type of problem in the past). The
problem is that the patch only touched the macros used by
early-quirks.c and by the user space components that rely on
i915_pciids.h, it didn't touch the macros used by i915_pci.c. So we
correctly handled the stolen memory for these theoretical IDs, but we
didn't actually drive the devices from i915.ko.

So this patch fixes the original commit by actually making i915.ko
drive these IDs, which was the goal. There's no information on what
would be the GT count on these IDs, so we just go with the safer
intel_broadwell_info, at the risk of ignoring a possibly inexistent
BSD2_RING.

I did some checking, and it seems that these IDs are driven by
intel-gpu-tools, xf86-video-intel and libdrm (since they contain old
copies of i915_pciids.h), but they are not checked by mesa.

The alternative to this patch would be to just assume we're actually
never going to use these IDs, and then remove them from our ID lists
and make sure our user space components sync the latest i915_pciids.h
copy. I'm fine with either approaches, as long as we make sure that
every component tries to drive the same list of PCI IDs.

Fixes: fb7023e0 ("drm/i915: BDW: Adding Reserved PCI IDs.")
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1483473860-17644-3-git-send-email-paulo.r.zanoni@intel.com
      98b2f01c