Added a new function which waits for the ringbuffer space to be equal to
(total - 8). This is the empty condition of the ringbuffer, and
equivalent to head==tail.
Also modified two users of this functionality elsewhere in the code.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Required so that we don't obliterate the queue if initialising the
rings after the global IRQ handler is installed.
[Jesse, you recently looked at refactoring the IRQ installation
routines, does moving the initialisation of ring buffer data structures away
from that routine make sense in your grand scheme?]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
We always skipped flushing the BLT ring if the request flush did not
include the RENDER domain. However, this neglects that we try to flush
the COMMAND domain after every batch and before the breadcrumb interrupt
(to make sure the batch is indeed completed prior to the interrupt
firing and so insuring CPU coherency). As a result of the missing flush,
incoherency did indeed creep in, most notable when using lots of command
buffers and so potentially rewritting an active command buffer (i.e.
the GPU was still executing from it even though the following interrupt
had already fired and the request/buffer retired).
As all ring->flush routines now have the same preconditions, de-duplicate
and move those checks up into i915_gem_flush_ring().
Fixes gem_linear_blit.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=35284
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: mengmeng.meng@intel.com
Grab the latest stabilisation bits from -fixes and some suspend and
resume fixes from linus.
Conflicts:
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/i915_irq.c
A lot of minor tweaks to fix the tracepoints, improve the outputting for
ftrace, and to generally make the tracepoints useful again. It is a start
and enough to begin identifying performance issues and gaps in our
coverage.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Instead of reporting EIO upfront in the entrance of an ioctl that may or
may not attempt to use the GPU, defer the actual detection of an invalid
ioctl to when we issue a GPU instruction. This allows us to continue to
use bo in video memory (via pread/pwrite and mmap) after the GPU has hung.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
During suspend, Linus found that his machine would hang for 3 seconds,
and identified that intel_ring_buffer_wait() was the culprit:
"Because from looking at the code, I get the notion that
"intel_read_status_page()" may not be exact. But what happens if that
inexact value matches our cached ring->actual_head, so we never even
try to read the exact case? Does it _stay_ inexact for arbitrarily
long times? If so, we might wait for the ring to empty forever (well,
until the timeout - the behavior I see), even though the ring really
_is_ empty."
As the reported HEAD position is only updated every time it crosses a
64k boundary, whilst draining the ring it is indeed likely to remain one
value. If that value matches the last known HEAD position, we never read
the true value from the register and so trigger a timeout.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
As the IMR for the USER interrupts are not modified elsewhere, we can
separate the spinlock used for these from that of hpd and pipestats.
Those two IMR are manipulated under an IRQ and so need heavier locking.
Reported-and-tested-by: Alexey Fisher <bug-track@fisher-privat.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
On i830 if the tail pointer is set to within 2 cachelines of the end of
the buffer, the chip may hang. So instead if the tail were to land in
that location, we pad the end of the buffer with NOPs, and start again
at the beginning.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Restore PIPE_CONTROL once again just for Ironlake, as it appears that
MI_USER_INTERRUPT does not have the same coherency guarantees, that is
on Ironlake the interrupt following a GPU write is not guaranteed to
arrive after the write is coherent from the CPU, as it does on the
other generations.
Reported-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Reported-by: Shuang He <shuang.he@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=32402
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
In order to enforce the correct memory barriers for irq get/put, we need
to perform the actual counting using atomic operations.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
If the tail advances beyond the autoreport HEAD value, then we need to
fallback to an uncached read of the HEAD register in order to ascertain
the correct amount of remaining space in the ringbuffer.
Reported-by: Fang, Xun <xunx.fang@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=32259
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
The workaround is hideous and we are using the STORE_DWORD on all other
generations on all other rings, so use for the gen5 render ring as
well.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
There's not much we can do here but hope for the best. However the first
failure happens quite frequently and if often remedied by the second
attempt to reset HEAD. So only print the error if that attempt also
fails.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=19802
Reported-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
The bulk of the change is to convert the growing list of rings into an
array so that the relationship between the rings and the semaphore sync
registers can be easily computed.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
This makes the various rings more consistent by removing the anomalous
handing of the rendering ring execbuffer dispatch.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
The pipe control object is allocated by the device for the sole use of the
render ringbuffer. Move this detail from the general code to the render
ring buffer initialisation.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Before reading ring register, set FORCE_WAKE bit to prevent GT core
power down to low power state, otherwise we may read stale values.
Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
[ickle: added a udelay which seemed to do the trick on my SNB]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
My Sandybridge only reports 0 for the ring buffer registers, causing it
to hang as soon as we exhaust the available ring. As a workaround, take
advantage of our huge ring buffers and use the auto-reporting mechanism
to update the status page with the HEAD location every 64 KiB.
Cherry-picked from 6aa56062ea.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=31404
Tested-by: Zhao Jian <jian.j.zhao@intel.com>
Cc: stable@kernel.org
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
The ring buffer registers return 0 whilst idle (for some values of idle)
on early Sandybridge hw. Persevere even when all appears hopeless...
Fortunately the head auto-reporting prevents most hangs.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=31370
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
a00b10c360 "Only enforce fence limits inside the GTT" also
added a fenceable/mappable disdinction when binding/pinning buffers.
This only complicates the code with no pratical gain:
- In execbuffer this matters on for g33/pineview, as this is the only
chip that needs fences and has an unmappable gtt area. But fences
are only possible in the mappable part of the gtt, so need_fence
implies need_mappable. And need_mappable is only set independantly
with relocations which implies (for sane userspace) that the buffer
is untiled.
- The overlay code is only really used on i8xx, which doesn't have
unmappable gtt. And it doesn't support tiled buffers, currently.
- For all other buffers it's a bug to pass in a tiled bo.
In short, this disdinction doesn't have any practical gain.
I've also reverted mapping the overlay and context pages as possibly
unmappable. It's not worth being overtly clever here, all the big
gains from unmappable are for execbuf bos.
Also add a comment for a clever optimization that confused me
while reading the original patch by Chris Wilson.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
I presumed that we would be writing to the batch through the GTT having
bound it, so I converted it to use iomem. Even later as I spotted that
we didn't even move the batch to the GTT (now an issue since we default
to uncached memory on SNB) I still didn't realise that using iomem for
kmapped memory was incorrect. Fix it.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
On some stepping of SNB cpu, the first command to be parsed in BLT
command streamer should be MI_BATCHBUFFER_START otherwise the GPU
may hang.
(cherry picked from commit 8d19215be8)
Conflicts:
drivers/gpu/drm/i915/intel_ringbuffer.c
drivers/gpu/drm/i915/intel_ringbuffer.h
Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Cc: stable@kernel.org
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
On some stepping of SNB cpu, the first command to be parsed in BLT
command streamer should be MI_BATCHBUFFER_START otherwise the GPU
may hang.
Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
[ickle: rebased for -next]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
My Sandybridge only reports 0 for the ring buffer registers, causing it
to hang as soon as we exhaust the available ring. As a workaround, take
advantage of our huge ring buffers and use the auto-reporting mechanism
to update the status page with the HEAD location every 64 KiB.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
So long as we adhere to the fence registers rules for alignment and no
overlaps (including with unfenced accesses to linear memory) and account
for the tiled access in our size allocation, we do not have to allocate
the full fenced region for the object. This allows us to fight the bloat
tiling imposed on pre-i965 chipsets and frees up RAM for real use. [Inside
the GTT we still suffer the additional alignment constraints, so it doesn't
magic allow us to render larger scenes without stalls -- we need the
expanded GTT and fence pipelining to overcome those...]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Like before add a parameter mappable (also to gem_object_pin) and
set it depending upon the context. Only bos that are brought into
the gtt due to an execbuffer call can be put into the unmappable
part of the gtt, everything else (especially pinned objects) need
to be put into the mappable part of the gtt.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Preparing the ringbuffer for adding new commands can fail (a timeout
whilst waiting for the GPU to catch up and free some space). So check
for any potential error before overwriting HEAD with new commands, and
propagate that error back to the user where possible.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
The ringbuffer keeps a pointer to the parent device, so we can use that
instead of passing around the pointer on the stack.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
... to prevent flush processing of an idle (or even absent) ring.
This fixes a regression during suspend from 87acb0a5.
Reported-and-tested-by: Alexey Fisher <bug-track@fisher-privat.net>
Tested-by: Peter Clifton <pcjc2@cam.ac.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
This should fix the error along the reset path were we tried to clear the
tail register by setting it to 0, but were in fact setting it to the
current value and complaining when it did not reset to 0.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
