On Fri, Jan 03, 2020 at 01:22:11PM +0200, Mika Kuoppala wrote:
> Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> writes:
>
> > Empirically the minimal context image we use for rcs is insufficient to
> > state the engine. This is demonstrated if we poison the context image
> > such that any uninitialised state is invalid, and so if the engine
> > samples beyond our defined region, will fail to start.
Just out of curiosity, is this something we only need to worry about on
gen9 and not on gen11/gen12?
I'm not terribly familiar with the context management code, so I was
just curious how we know which parts of the context image are actually
important to define in the *cs_offsets[] arrays and which we can safely
leave uninitialized.
Thanks.
Matt
> >
> > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
>
> Reviewed-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
>
> > ---
> > drivers/gpu/drm/i915/gt/intel_lrc.c | 88 +++++++++++++++++++++++++-
> > drivers/gpu/drm/i915/gt/selftest_lrc.c | 7 ++
> > 2 files changed, 94 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
> > index 00895f83f61e..029496d2dfb5 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> > @@ -492,7 +492,7 @@ static u32 *set_offsets(u32 *regs,
> > const u8 *data,
> > const struct intel_engine_cs *engine)
> > #define NOP(x) (BIT(7) | (x))
> > -#define LRI(count, flags) ((flags) << 6 | (count))
> > +#define LRI(count, flags) ((flags) << 6 | (count) | BUILD_BUG_ON_ZERO(count >= BIT(6)))
> > #define POSTED BIT(0)
> > #define REG(x) (((x) >> 2) | BUILD_BUG_ON_ZERO(x >= 0x200))
> > #define REG16(x) \
> > @@ -728,6 +728,90 @@ static const u8 gen8_rcs_offsets[] = {
> > END(),
> > };
> >
> > +static const u8 gen9_rcs_offsets[] = {
> > + NOP(1),
> > + LRI(14, POSTED),
> > + REG16(0x244),
> > + REG(0x34),
> > + REG(0x30),
> > + REG(0x38),
> > + REG(0x3c),
> > + REG(0x168),
> > + REG(0x140),
> > + REG(0x110),
> > + REG(0x11c),
> > + REG(0x114),
> > + REG(0x118),
> > + REG(0x1c0),
> > + REG(0x1c4),
> > + REG(0x1c8),
> > +
> > + NOP(3),
> > + LRI(9, POSTED),
> > + REG16(0x3a8),
> > + REG16(0x28c),
> > + REG16(0x288),
> > + REG16(0x284),
> > + REG16(0x280),
> > + REG16(0x27c),
> > + REG16(0x278),
> > + REG16(0x274),
> > + REG16(0x270),
> > +
> > + NOP(13),
> > + LRI(1, 0),
> > + REG(0xc8),
> > +
> > + NOP(13),
> > + LRI(44, POSTED),
> > + REG(0x28),
> > + REG(0x9c),
> > + REG(0xc0),
> > + REG(0x178),
> > + REG(0x17c),
> > + REG16(0x358),
> > + REG(0x170),
> > + REG(0x150),
> > + REG(0x154),
> > + REG(0x158),
> > + REG16(0x41c),
> > + REG16(0x600),
> > + REG16(0x604),
> > + REG16(0x608),
> > + REG16(0x60c),
> > + REG16(0x610),
> > + REG16(0x614),
> > + REG16(0x618),
> > + REG16(0x61c),
> > + REG16(0x620),
> > + REG16(0x624),
> > + REG16(0x628),
> > + REG16(0x62c),
> > + REG16(0x630),
> > + REG16(0x634),
> > + REG16(0x638),
> > + REG16(0x63c),
> > + REG16(0x640),
> > + REG16(0x644),
> > + REG16(0x648),
> > + REG16(0x64c),
> > + REG16(0x650),
> > + REG16(0x654),
> > + REG16(0x658),
> > + REG16(0x65c),
> > + REG16(0x660),
> > + REG16(0x664),
> > + REG16(0x668),
> > + REG16(0x66c),
> > + REG16(0x670),
> > + REG16(0x674),
> > + REG16(0x678),
> > + REG16(0x67c),
> > + REG(0x68),
> > +
> > + END()
> > +};
> > +
> > static const u8 gen11_rcs_offsets[] = {
> > NOP(1),
> > LRI(15, POSTED),
> > @@ -832,6 +916,8 @@ static const u8 *reg_offsets(const struct intel_engine_cs *engine)
> > return gen12_rcs_offsets;
> > else if (INTEL_GEN(engine->i915) >= 11)
> > return gen11_rcs_offsets;
> > + else if (INTEL_GEN(engine->i915) >= 9)
> > + return gen9_rcs_offsets;
> > else
> > return gen8_rcs_offsets;
> > } else {
> > diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
> > index 9ec9833c9c7b..943b623f00e9 100644
> > --- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
> > +++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
> > @@ -3406,6 +3406,13 @@ static int live_lrc_layout(void *arg)
> > continue;
> > }
> >
> > + if (lrc[dw] == 0) {
> > + pr_debug("%s: skipped instruction %x at dword %d\n",
> > + engine->name, lri, dw);
> > + dw++;
> > + continue;
> > + }
> > +
> > if ((lri & GENMASK(31, 23)) != MI_INSTR(0x22, 0)) {
> > pr_err("%s: Expected LRI command at dword %d, found %08x\n",
> > engine->name, dw, lri);
> > --
> > 2.25.0.rc0
> _______________________________________________
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--
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation
(916) 356-2795
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