I couldn't figure out what drm_bo_type_dc was for; Dave Airlie finally clued
me in that it was the 'normal' buffer objects with kernel allocated pages
that could be mmapped from the drm device file.
I thought that 'drm_bo_type_device' was a more descriptive name.
I also added a bunch of comments describing the use of the type enum values and
the functions that use them.
Flags pending validation were stored in a misleadingly named field, 'mask'.
As 'mask' is already used to indicate pieces of a flags field which are
changing, it seems better to use a name reflecting the actual purpose of
this field. I chose 'proposed_flags' as they may not actually end up in
'flags', and in an case will be modified when they are moved over.
This affects the API, but not ABI of the user-mode interface.
Previously, dummy_read_page was used only for read-only user allocations; it
filled in pages that were not present in the user address map (presumably,
these were allocated but never written to pages).
This patch allows them to be used for read-only ttms allocated from the
kernel, so that applications can over-allocate buffers without forcing every
page to be allocated.
I'm hoping to use the dummy_read_page for kernel allocated buffers to avoid
allocating extra pages for read-only buffers (like vertex and batch buffers).
This also eliminates the 'write' parameter to drm_ttm_set_user and just
has DRM_TTM_PAGE_WRITE passed into drm_ttm_create.
Aside from changing drm_bind_ttm to drm_ttm_bind, this patch
adds only documentation and fixes the functions inside drm_ttm.c
to all be prefixed with drm_ttm_.
drivers/char/drm/mga_dma.c::mga_do_cleanup_dma() and I think there's a small
problem.
The variable is only used inside #if __OS_HAS_AGP which is fine, but all
that
ever happens is an assignment to the variable - it is never actually used
for
anything. The variable is nicely initialized to zero which is also what the
return statement at the end of function returns (always at the moment).
It looks to me like that function should be returning 'err' instead of
always
just returning 0. Here's a patch to do that.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
drmBOSetStatus does not bother to set the fence_class parameter.
Fortunately, drm_bo_setstatus_ioctl doesn't end up using it as it
calls drm_bo_handle_validate with use_old_fence_class = 1.
Document parameters and usage for drm_bo_handle_validate. Change parameter
order to match drm_bo_do_validate (fence_class has been moved to after
flags, hint and mask values). Existing users of this function have been
changed, but out-of-tree users must be modified separately.
Add comments about the parameters to drm_bo_do_validate, along
with comments for the DRM_BO_HINT options. Remove the 'do_wait'
parameter as it is duplicated by DRM_BO_HINT_DONT_BLOCK.
Creating a ttm was done with drm_ttm_init while destruction was done with
drm_destroy_ttm. Renaming these to drm_ttm_create and drm_ttm_destroy makes
their use clearer. Passing page_flags to the create function will allow that
to know whether user or kernel pages are needed, with the goal of allowing
kernel ttms to be saved for later reuse.
One of the costs of superioctl has been the need to perform relocations
inside the kernel. The cost of mapping the buffers to the CPU and writing
data is fairly high, especially if those buffers have been mapped and read
by the GPU.
If we assume that buffers don't move around very often, we can have the
client compute the relocations itself using the previous GPU address. When
that object doesn't move, the kernel can skip computing and writing the
updated data.
Here's a patch which adds a new field to struct drm_bo_info_req called
'presumed_offset', and a new DRM_BO_HINT_PRESUMED_OFFSET that is set when
this field has been filled in by the client.
There are two separate optimizations performed when the presumed_offset is
correct:
1. i915_exec_reloc checks to see if all previous buffer offsets were guessed
correctly. If so, there's no need for it to look at *any* of the
relocations for a buffer. When this happens, it skips the whole
relocation process, simply returning success.
2. i915_apply_reloc checks to see if the target buffer offset was guessed
correctly. If so, it skips mapping the relocatee, computing the
relocation and writing the value. If no relocations are needed, the
relocatee should never be mapped to the CPU, and so the kernel shouldn't
need to wait for any fences to pass.
If drmMinor >= 6, the intel DDX driver will enable vblank events on both
pipes. If drmMinor >= 10 on pre-965 chipsets, the intel DDX driver will
swap the pipe<->plane mapping to allow for framebuffer compression on
laptop screens. This means the secondary vblank counter (corresponding
to pipe B) will be incremented when vblank interrupts occur.
Now Mesa waits for vblank events on whichever plane has a greater
portion of the displayed window. So it will happly ask to wait for the
primary counter even though that one won't increment.
So we can fix this in either the DDX driver, Mesa or the kernel (though
I thought we already had several times).
Since current (and previous) userspace assumes it's talking about a pipe
== plane situation and now uses planes when talking to the kernel, we
should probably just hide the mapping details there (indeed they already
are hidden there for vblank swaps), which this patch does.
So as far as userland is concerned, whether we call things planes or
pipes is irrelevant, as long as kernel developers understand that
userland hands them planes and they have to figure out which pipe that
corresponds to (which will typically be the same on 965+ hardware and
reversed on pre-965 mobile chips).
Keith Packard
Dave Airlie
Jerome Glisse
Dave Airlie
Jakob Bornecrantz
Li Zefan
Jesper Juhl
Patrice Mandin
Alan Hourihane
José Fonseca
Jesse Barnes