[Intel-gfx] [PATCH 0/3] Describe chipsets in struct intel_device_info
krh at bitplanet.net
Wed Dec 16 12:16:14 PST 2009
This patch series implements a change in how we detect chipsets and their
capabilities. Our IS_* macros are a pretty confusing, twisted maze to figure
out and they expand to a ton of equality tests (try counting how many
comparisons I915_HAS_FBC() expands to and how many of them overlap).
These patches introduce a struct intel_device_info, that has a bitfield
that describe which familiy (i8xx, i9xx etc) the chipset belongs to and
which capabilities is has (fbc, needs_cursor_physical etc). We map the
PCI ID of a chipset to one of these structs through the pci_device_id table
and make it available through dev_priv->info.
It's a lot less code than what I thought it would be and the collection of
struct intel_device_info structs provide a nice catalog of the intel
chipsets and their capabilities. It's a nice cleanup on it's own, but
it turns out that it drops 10% (!!!1) of the stripped driver size. This
particular build goes from 216K to 196K. Not that driver size is a concern,
and 20K savings in a typical Linux distro isn't gettng anybody excited,
but that 10% of the generated code came from the IS_* macros is surprising...
Did a bit of benchmarking using cairo-perf-trace in the hope that eliminating
some of these big conditionals in the fast path would should up, but I couldn't
measure any difference.
[ Resend - git send-email doesn't support mboxes as advertised is seems ]
Kristian Høgsberg (3):
drm/i915: Move PCI IDs into i915 driver
drm/i915: Implement IS_* macros using static tables
drm/i915: Track whether cursor needs physical address in
drivers/gpu/drm/i915/i915_dma.c | 12 +---
drivers/gpu/drm/i915/i915_drv.c | 121 +++++++++++++++++++++++++++++++++-
drivers/gpu/drm/i915/i915_drv.h | 115 ++++++++++++++------------------
drivers/gpu/drm/i915/intel_display.c | 4 +-
4 files changed, 172 insertions(+), 80 deletions(-)
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