v2: Rebased onto Paulo's MHz->kHz change.

v3: Rebased on top of the Haswell pc8+ adjustements.

v4: Use the exact 337.5MHz clock, should have been done as part of v2.
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v1)
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

And it inherits some bits from the previous TRANS_CONF (aka PIPE_CONF
on previous gens).

v2: Rebase on to of the pipe config bpp handling rework.

v3: Rebased on top of the pipe_config->dither refactoring.

v4: Drop the read-modify-write cycle for PIPEMISC, similarly to how we
now also build up PIPECONF completely ourselves - keeping around
random stuff set by the BIOS just isn't a good idea. I've checked BDW
BSpec and we already set all relevant bits.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v1)
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

So you can use the panel fitter while the power well is disabled and
you also don't need to set the "pipe" bit.

v2: Rebased on top of Jesse's pfit refactor, which moved pfit state
into the pipe_config.

v3: Rebase on top of the latest Haswell/panel fitter rework, which
neatly resolves a FIXME we have in this patch here:

v4: Rebase on top of the new power domain framework.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v1)
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

The platforms we currently have all have LPT LP on them. As such, we
have no way to identify the new WPT PCH that will ship with Broadwell.

NOTE: For all purposes relevant to the driver that this point, LPT and
WPT are equivalent. Therefore there should be no need to actually change
this for some time.

v2: Don't assign dev_priv->num_pch_pll any more.

v3: Rebase on top of the PCH detection changes for virtualized
enviroments.

v4: Wrote commit message

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> (v3)
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Just like Haswell, but with the small twist that the panel fitter for pipe A is
now also in the always-on power well.

v2: Use the new HAS_POWER_WELL macro.

v3: Rebase on top of intel_using_power_well patches.

v4: This time actually update the PFIT check correctly so that the
pipe A pfit is in the always-on domain.

v5: Rebase on top of the VGA power domain addition.

v6: Rebase on top of the new power domain infrastructure. Also pimp the commit
message a bit while at it.

v7: Use IS_BROADWELL instead of IS_GEN8 (Ville).

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v1)
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Just make Broadwell follow the same code paths as Haswell here,
instead of running code for the even-older platforms.

v2: Shuffle around Ben's vma prep work.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

v2: Rebase (Paulo Zanoni)

v3: Rebase on top of num_pipes having moved to intel_device_info.

Signed-off-by: Damien Lespiau <damien.lespiau@intel.com> (v1)
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> (v2)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

For now it's just equivalent to IS_GEN8, but in the future we might
want to change that (e.g., on Gen 7 we have IS_VALLEYVIEW,
IS_IVYBRIDGE and IS_HASWELL).
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

This was an oversight and should have been in a previous series
somewhere.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

It's not so much that the information is terribly useful, but rather
that the gen6/7 information is completely useless.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

v2: Resolve rebase conflicts and switch to gen < 8 color for GenX
checking.

v3: Rebase on top of the address space refactoring.
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

PIPE_CONTROL added the high address dword. I'm not sure how the
simulator let me get away with this. I've explicitly left out all the
workarounds from Gen7 because in the minimal digging that I did, most
don't seem necessary, and the simulator doesn't complain without them

Note that BLT and BSD ring commands had already been updated previously.
Just render/pipe_control should have been broken.

v2: Squash in a fixup from Ville to follow the recent IVB PIPE_CONTROL
updates: "BDW uses the IVB PIPE_CONTROL style for specifying GTT vs.
PPGTT for the PIPE_CONTROL QW/DW write."

v3: Rebase on top of Chris' cleanup to have an explicit ring->scratch
buffer object instead of an opaque ring->private where everyone stores
the same stuff inside.
Reported-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net> (for the fixup)
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

v2: Squash in fix from Ben: Set PPGTT batches as necessary

This fixes the regression in the last couple of days when we enabled
PPGTT.

v3: Squash in fixup to still use GTT for secure batches from Ville:

BDW doesn't have a separate secure vs. non-secure bit in
MI_BATCH_BUFFER_START. So for secure batches we have to simply
leave the PPGTT bit unset. Fortunately older generations (except
HSW) had similar limitations so execbuffer already creates a GTT
mapping for all secure batches.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Legacy PPGTT on GEN8 requires programming 4 PDP registers per ring.
Since all rings are using the same address space with the current code
the logic is simply to program all the tables we've setup for the PPGTT.

v2: Turn on PPGTT in GFX_MODE

v3: v2 was the wrong patch

v4: Resolve conflicts due to patch series reordering.

v5: Squash in fixup from Ben: Use LRI to write PDPs

The docs (and simulator seems to back up) suggest that we can only
program legacy PPGTT PDPs with LRI commands.

v6: Rebase around context differences conflicts.

v7: Use #defines for per ring PDPs. (Damien)

v8: Don't use typede'f private_t.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (up to v3 and v7)
Reviewed-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

GEN8 insertion is very similar to GEN6.

v2: Rebase on top of Imre's for_each_sg_page helpers.

v3: Fixup my conversion (spotted by Ville).

v4: Rebase on top of the address space refactoring.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

GEN8 PPGTT range clearing is very similar to GEN6 if we assume that our
PDEs are all valid, which they should be.

v2: Rebase on top of the address space refactoring.

v3: Rebase on top of the bool use_scratch addition to the clear_range interface.
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

The upcoming clear and insert routines will expect that PDEs all point
to valid Page Directories. Doing that lazily doesn't really buy us
anything.

The page allocation is done regardless earlier in init so it shouldn't
hurt set the PDEs.

v2: Squash in patches to implement fixed PDE write function:

- If I had done this in the first place, the bug that's going to be
  fixed in an upcoming patch would have been much easier to find.

- Use WB for PDEs.

  The PAT bit is used for page size. 2ME PDEs aren't even supported in
  BDW, so this was completely invalid. The solution is to make our
  PDEs WB+LLC instead of the pervious WB+eLLC. As far as I can guess,
  this change won't matter for performance.

  Thanks to Ville for the quick correction when discussing on IRC.

v3: Return the pde type for pde encoding (Damien)
Reviewed-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Aside from the potential size increase of the PPGTT, the primary
difference from previous hardware is the Page Directories are no longer
carved out of the Global GTT.

Note that the PDE allocation is done as a 8MB contiguous allocation,
this needs to be eventually fixed (since driver reloading will be a
pain otherwise). Also, this will be a no-go for real PPGTT support.

v2: Move vtable initialization

v3: Resolve conflicts due to patch series reordering.

v4: Rebase on top of the address space refactoring of the PPGTT
support. Drop Imre's r-b tag for v2, too outdated by now.

v5: Free the correct amount of memory, "get_order takes size not a page
count." (Imre)
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

BDW caching works differently than the previous generations. Instead of
having bits in the PTE which directly control how the page is cached,
the 3 PTE bits PWT PCD and PAT provide an index into a PAT defined by
register 0x40e0. This style of caching is functionally equivalent to how
it works on HSW and before.

v2: Tiny bikeshed as discussed on internal irc.

v3: Squash in patch from Ville to mirror the x86 PAT setup more like
in arch/x86/mm/pat.c. Primarily, the 0th index will be WB, and not
uncached.

v4: Comment for reason to not use a 64b write on the PPAT.

v5: Add a FIXME comment that the caching bits in the PAT registers
might be wrong due to doc confusion.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

With the PTE clarifications, the bind and clear functions can now be
added for gen8.

v2: Use for_each_sg_pages in gen8_ggtt_insert_entries.

v3: Drop dev argument to pte encode functions, upstream lost it. Also
rebase on top of the scratch page movement.

v4: Rebase on top of the new address space vfuncs.

v5: Add the bool use_scratch argument to clear_range and the bool valid argument
to the PTE encode function to follow upstream changes.

v6: Add a FIXME(BDW) about the size mismatch of the readback check
that Jon Bloomfield spotted.

v7: Squash in fixup patch from Ben for the posting read to match the
64bit ptes and so shut up the WARN.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

With gen6 PTE type in place, pave the way for the new gen8 type.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Probing gen8 is similar to gen6. To make the code cleaner and more
maintainable however we can use the probe functions to split it out.

v2: Rebased on top of update gtt probe infrastructure.

v3: Rebased on top of Kenneth' Graunke's ->pte_encode refactoring.

V4: Resolve conflicts with Ben's latest ppgtt patches, also switch to
gen < 8 testing instead of gen <= 7.

v5: Resolve conflicts with address space vfunc changes in upstream.

v6: Use 39b DMA mask. At least, for this mode, it is the correct mask.
(Imre)

Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

All the gen8 debugfs stuff I wasn't too lazy to update. We'll need more
later, I am certain.

v2: Fix up the register name in the debugfs output as suggested by
Paulo.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Reviewed-by: Paulo Zanoni <przanoni@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

The code is more verbose than necessary for the reader's sake, hopefully
the compiler optimizes away the if.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

The command to emit batch buffers has changed to address 48b addresses.
It seemed reasonable that we could still use the old instruction where
emitting 0 for length would do the right thing, but it seems to bother
the simulator when the code does that.

Now the second dword in the command has the upper 16b of the address of
the batchbuffer.

v2: Remove duplicated vfun assignment.

v3: Squash in VECS support changes from Zhao Yakui <yakui.zhao@intel.com>

v4: Make checkpatch happy.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v2)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

We don't actually return any to userspace yet, however we can pretend
like we do now so userspace will support it when it happens.

This is just to please Chris as the code itself isn't ready for > 64b
relocations.

v2: Rebase on top of the refactored relocate_entry_gtt|cpu functions.

v3: Squash in fixup from Rafal Barbalho for 64 byte relocs using cpu
relocs and those crossing a page boundary.

v4: Squash in a fixup for the fixup from Rafael.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Signed-off-by: Barbalho, Rafael <rafael.barbalho@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

v2: Add missed ring interrupt info
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

The interrupt handling implementation remains the same as previous
generations with the 4 types of registers, status, identity, mask, and
enable. However the layout of where the bits go have changed entirely.
To address these changes, all of the interrupt vfuncs needed special
gen8 code.

The way it works is there is a top level status register now which
informs the interrupt service routine which unit caused the interrupt,
and therefore which interrupt registers to read to process the
interrupt. For display the division is quite logical, a set of interrupt
registers for each pipe, and in addition to those, a set each for "misc"
and port.

For GT the things get a bit hairy, as seen by the code. Each of the GT
units has it's own bits defined. They all look *very similar* and
resides in 16 bits of a GT register. As an example, RCS and BCS share
register 0. To compact the code a bit, at a slight expense to
complexity, this is exactly how the code works as well. 2 structures are
added to the ring buffer so that our ring buffer interrupt handling code
knows which ring shares the interrupt registers, and a shift value (ie.
the top or bottom 16 bits of the register).

The above allows us to kept the interrupt register caching scheme, the
per interrupt enables, and the code to mask and unmask interrupts
relatively clean (again at the cost of some more complexity).

Most of the GT units mentioned above are command streamers, and so the
symmetry should work quite well for even the yet to be implemented rings
which Broadwell adds.

v2: Fixes up a couple of bugs, and is more verbose about errors in the
Broadwell interrupt handler.

v3: fix DE_MISC IER offset

v4: Simplify interrupts:
I totally misread the docs the first time I implemented interrupts, and
so this should greatly simplify the mess. Unlike GEN6, we never touch
the regular mask registers in irq_get/put.

v5: Rebased on to of recent pch hotplug setup changes.

v6: Fixup on top of moving num_pipes to intel_info.

v7: Rebased on top of Egbert Eich's hpd irq handling rework. Also
wired up ibx_hpd_irq_setup for gen8.

v8: Rebase on top of Jani's asle handling rework.

v9: Rebase on top of Ben's VECS enabling for Haswell, where he
unfortunately went OCD on the gt irq #defines. Not that they're still
not yet fully consistent:
- Used the GT_RENDER_ #defines + bdw shifts.
- Dropped the shift from the L3_PARITY stuff, seemed clearer.
- s/irq_refcount/irq_refcount.gt/

v10: Squash in VECS enabling patches and the gen8_gt_irq_handler
refactoring from Zhao Yakui <yakui.zhao@intel.com>

v11: Rebase on top of the interrupt cleanups in upstream.

v12: Rebase on top of Ben's DPF changes in upstream.

v13: Drop bdw from the HAS_L3_DPF feature flag for now, it's unclear what
exactly needs to be done. Requested by Ben.

v14: Fix the patch.
- Drop the mask of reserved bits and assorted logic, it doesn't match
  the spec.
- Do the posting read inconditionally instead of commenting it out.
- Add a GEN8_MASTER_IRQ_CONTROL definition and use it.
- Fix up the GEN8_PIPE interrupt defines and give the GEN8_ prefixes -
  we actually will need to use them.
- Enclose macros in do {} while (0) (checkpatch).
- Clear DE_MISC interrupt bits only after having processed them.
- Fix whitespace fail (checkpatch).
- Fix overtly long lines where appropriate (checkpatch).
- Don't use typedef'ed private_t (maintainer-scripts).
- Align the function parameter list correctly.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v4)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

bikeshed

All the BARs have the ability to grow.

v2: Pulled out the simulator workaround to a separate patch.
Rebased.

v3: Rebase onto latest vlv patches from Jesse.

v4: Rebased on top of the early stolen quirk patch from Jesse.

v5: Use the new macro names.
s/INTEL_BDW_PCI_IDS_D/INTEL_BDW_D_IDS
s/INTEL_BDW_PCI_IDS_M/INTEL_BDW_M_IDS
It's Jesse's fault for not following the convention I originally set.

Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Just enough to make the code not barf...

Init BDW display to look like HSW. For the simulator this should be
fine, but this will probably require more work.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
[danvet: Add a FIXME comment about RCS flips being untested on bdw.
Also add a note that hblank events are reserved on bdw+ in DERRMR.]
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Clock gating init is really a catch all function for registers we need
to write early in loading the driver.

Atm just the bare metal stuff we need, more will surely come.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

BDW context sizes varies a bit.

v2: Squash in fixup for the hw context size from Ben.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

v2: Squash in "drm/i915/bdw: Add BDW to the HAS_DDI check" as
suggested by Damien.

v3: Squash in VEBOX enabling from  Zhao Yakui <yakui.zhao@intel.com>

v4: Rebase on top of Jesse's patch to extract all pci ids to
include/drm/i915_pciids.h.

v4: Replace Halo by its marketing moniker Iris. Requested by Ben.

v5: Switch from info->has*ring to info->ring_mask.

v6: Add 0x16X2 variant (which is newer than this patch)
Rename to use new naming scheme (Chris)
Remove Simulator PCI ids. These snuck in during rebase (Chris)

v7: Fix poor sed job from v6
Make the desktop variants use the desktop macro (Rebase error). Notice
that this makes no functional difference - it's just confusing.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

This will be changed once the gen8 code is fully implemented.

v2: Use ENOSYS instead of ENXIO as suggested by Chris.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Somehow this got missed or dropped during development. The simulator
does not use forcewake, so it's entirely possible it never worked
correctly. After the mmio rework, this will end up in an OOPs, and the
system will not boot.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
[danvet: Use IS_GEN8 instead of IS_BROADWELL.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

GEN8 removes the GT FIFO which we've all come to know and love. Instead
it offers a wider range of optimized registers which always keep a
shadowed copy, and are fed to the GPU when it wakes.

How this is implemented in hardware is still somewhat of a mystery. As
far as I can tell, the basic design is as follows:

If the register is not optimized, you must use the old forcewake
mechanism to bring the GT out of sleep. [1]

If register is in the optimized list the write will signal that the
GT should begin to come out of whatever sleep state it is in.

While the GT is coming out of sleep, the requested write will be stored
in an intermediate shadow register.

Do to the fact that the implementation details are not clear, I see
several risks:
1. Order is not preserved as it is with GT FIFO. If we issue multiple
writes to optimized registers, where order matters, we may need to
serialize it with forcewake.
2. The optimized registers have only 1 shadowed slot, meaning if we
issue multiple writes to the same register, and those values need to
reach the GPU in order, forcewake will be required.

[1] We could implement a SW queue the way the GT FIFO used to work if
desired.

NOTE: Compile tested only until we get real silicon.

v2:
- Use a default case to make future platforms also work.
- Get rid of IS_BROADWELL since that's not yet defined, but we want to
  MMIO as soon as possible.

v3: Apply suggestions from Mika's review:
- s/optimized/shadowed/
- invert the logic of the helper so that it does what it says (the
  code itself was correct, just confusing to read).

v4:
- Squash in lost break.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v1)
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

No PCI ids yet, so nothing should happen.

Rebase-Note: This one needs replacement ;-)
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>