| Message ID | 20221118124816.545034-1-matthew.auld@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] drm/i915/migrate: Account for the reserved_space | expand |
On 11/18/2022 1:48 PM, Matthew Auld wrote: > From: Chris Wilson <chris.p.wilson@intel.com> > > If the ring is nearly full when calling into emit_pte(), we might > incorrectly trample the reserved_space when constructing the packet to > emit the PTEs. This then triggers the GEM_BUG_ON(rq->reserved_space > > ring->space) when later submitting the request, since the request itself > doesn't have enough space left in the ring to emit things like > workarounds, breadcrumbs etc. > > Testcase: igt@i915_selftests@live_emit_pte_full_ring > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/7535 > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6889 > Fixes: cf586021642d ("drm/i915/gt: Pipelined page migration") > Signed-off-by: Chris Wilson <chris.p.wilson@intel.com> > Signed-off-by: Matthew Auld <matthew.auld@intel.com> > Cc: Andrzej Hajda <andrzej.hajda@intel.com> > Cc: Nirmoy Das <nirmoy.das@intel.com> Tested this on ATS-M. Tested-by: Nirmoy Das <nirmoy.das@intel.com> Reviewed-by: Nirmoy Das <nirmoy.das@intel.com> > Cc: <stable@vger.kernel.org> # v5.15+ > --- > drivers/gpu/drm/i915/gt/intel_migrate.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_migrate.c b/drivers/gpu/drm/i915/gt/intel_migrate.c > index b405a04135ca..48c3b5168558 100644 > --- a/drivers/gpu/drm/i915/gt/intel_migrate.c > +++ b/drivers/gpu/drm/i915/gt/intel_migrate.c > @@ -342,6 +342,16 @@ static int emit_no_arbitration(struct i915_request *rq) > return 0; > } > > +static int max_pte_pkt_size(struct i915_request *rq, int pkt) > +{ > + struct intel_ring *ring = rq->ring; > + > + pkt = min_t(int, pkt, (ring->space - rq->reserved_space) / sizeof(u32) + 5); > + pkt = min_t(int, pkt, (ring->size - ring->emit) / sizeof(u32) + 5); > + > + return pkt; > +} > + > static int emit_pte(struct i915_request *rq, > struct sgt_dma *it, > enum i915_cache_level cache_level, > @@ -388,8 +398,7 @@ static int emit_pte(struct i915_request *rq, > return PTR_ERR(cs); > > /* Pack as many PTE updates as possible into a single MI command */ > - pkt = min_t(int, dword_length, ring->space / sizeof(u32) + 5); > - pkt = min_t(int, pkt, (ring->size - ring->emit) / sizeof(u32) + 5); > + pkt = max_pte_pkt_size(rq, dword_length); > > hdr = cs; > *cs++ = MI_STORE_DATA_IMM | REG_BIT(21); /* as qword elements */ > @@ -422,8 +431,7 @@ static int emit_pte(struct i915_request *rq, > } > } > > - pkt = min_t(int, dword_rem, ring->space / sizeof(u32) + 5); > - pkt = min_t(int, pkt, (ring->size - ring->emit) / sizeof(u32) + 5); > + pkt = max_pte_pkt_size(rq, dword_rem); > > hdr = cs; > *cs++ = MI_STORE_DATA_IMM | REG_BIT(21);
diff --git a/drivers/gpu/drm/i915/gt/intel_migrate.c b/drivers/gpu/drm/i915/gt/intel_migrate.c index b405a04135ca..48c3b5168558 100644 --- a/drivers/gpu/drm/i915/gt/intel_migrate.c +++ b/drivers/gpu/drm/i915/gt/intel_migrate.c @@ -342,6 +342,16 @@ static int emit_no_arbitration(struct i915_request *rq) return 0; } +static int max_pte_pkt_size(struct i915_request *rq, int pkt) +{ + struct intel_ring *ring = rq->ring; + + pkt = min_t(int, pkt, (ring->space - rq->reserved_space) / sizeof(u32) + 5); + pkt = min_t(int, pkt, (ring->size - ring->emit) / sizeof(u32) + 5); + + return pkt; +} + static int emit_pte(struct i915_request *rq, struct sgt_dma *it, enum i915_cache_level cache_level, @@ -388,8 +398,7 @@ static int emit_pte(struct i915_request *rq, return PTR_ERR(cs); /* Pack as many PTE updates as possible into a single MI command */ - pkt = min_t(int, dword_length, ring->space / sizeof(u32) + 5); - pkt = min_t(int, pkt, (ring->size - ring->emit) / sizeof(u32) + 5); + pkt = max_pte_pkt_size(rq, dword_length); hdr = cs; *cs++ = MI_STORE_DATA_IMM | REG_BIT(21); /* as qword elements */ @@ -422,8 +431,7 @@ static int emit_pte(struct i915_request *rq, } } - pkt = min_t(int, dword_rem, ring->space / sizeof(u32) + 5); - pkt = min_t(int, pkt, (ring->size - ring->emit) / sizeof(u32) + 5); + pkt = max_pte_pkt_size(rq, dword_rem); hdr = cs; *cs++ = MI_STORE_DATA_IMM | REG_BIT(21);