drm/i915: Extend the parser to check register writes against a mask/value pair.

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In some cases it might be unnecessary or dangerous to give userspace
the right to write arbitrary values to some register, even though it
might be desirable to give it control of some of its bits.  This patch
extends the register whitelist entries to contain a mask/value pair in
addition to the register offset.  For registers with non-zero mask,
any LRM writes and LRI writes where the bits of the immediate given by
the mask don't match the specified value will be rejected.

This will be used in my next patch to grant userspace partial write
access to some sensitive registers.

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Reviewed-by: Zhigang Gong <zhigang.gong@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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Francisco Jerez 2015-05-29 16:44:14 +03:00 • committed by Daniel Vetter

parent 6a65c5b932

commit 4e86f725ce

2 changed files with 96 additions and 47 deletions

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138

drivers/gpu/drm/i915/i915_cmd_parser.c

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5

drivers/gpu/drm/i915/intel_ringbuffer.h

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