Release per screen DRI driver configs during screen destruction.

This rewrites the sparc GLAPI code so that it's PIC friendly and works
with all of the TLS/PTHREADS/64-bit/32-bit combinations properly.

As a result we can turn SPARC asm back on.  Currently it's only
enabled on Linux, as that's the only place where I can test this
stuff out.

For the moment the cliptest SPARC asm routines are disabled as they
are non-working.  The problem is that they use register %g7 as a
temporary which is where the threading libraries store the thread
pointer on SPARC.  I will fix that code up in a future change as it's
a pretty important routine to optimize.

Like x86 we do the runtime patch as a pthread once-invoked initializer
in init_glapi_relocs().

Unlike x86, however, our GLAPI stubs on SPARC are just two instruction
sequences that branch to a trampoline and put the GLAPI offset into a
register.  The trampoline is what we run-time patch.  The stubs thus
all look like:

glFoo:
	ba		__glapi_sparc_foo_stub
	 sethi		GLAPI_OFFSET(glFOO) * PTR_SIZE, %g3

This actually makes generate_entrypoint() a lot simpler on SPARC.  For
this case in generate_entrypoint() we generate stubs using a 'call'
instead of the 'ba' above to make sure it can reach.

In order to get a proper tail call going here, in the unpatched case,
we do several tricks.  To get the current PC, for example, we save the
return address register into a temporary, do a call, save the return
address register written by the call to another temporary, then
restore the original return address register value.  This is to
avoid having to allocate a stack frame.

This is necessary for PIC address formation.

This new GLAPI scheme lets us get rid of the ugly SPARC GLAPI hacks in
__glXInitialize() and one_time_init().

Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 62688f1135.

This reverts commit 5369876501.

This uses a GLX VendorPrivate request. VendorPrivates are real GLX API
calls but use the same protocol request. XCB does not currently
support specific VendorPrivetes directly. See eg.:
http://lists.freedesktop.org/archives/xcb/2008-November/004036.html
for more information.

Embed the macro body into do { ... } while(0) .

Embed the macro body into do { ... } while(0) .

Under the terms of version 1.1, "once Covered Code has been published
under a particular version of the License, Recipient may, for the
duration of the License, continue to use it under the terms of that
version, or choose to use such Covered Code under the terms of any
subsequent version published by SGI."

FreeB 2.0 license refers to "dates of first publication".  They are here
taken to be 1991-2000, as noted in the original license text:

 ** Original Code. The Original Code is: OpenGL Sample Implementation,
 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
 ** Copyright in any portions created by third parties is as indicated
 ** elsewhere herein. All Rights Reserved.

Official FreeB 2.0 text:

http://oss.sgi.com/projects/FreeB/SGIFreeSWLicB.2.0.pdf

As always, this code has not been tested for conformance with the OpenGL
specification.  OpenGL conformance testing is available from
http://khronos.org/ and is required for use of the OpenGL logo in
product advertising and promotion.

Was only used to get the PUBLIC/USED macros.
Also, replace "GL_FALSE" with "False" in a couple places.

this disables accelerated DRI and fallbacks to client-side software rendering.

compile-tested only.

caveats:

- does not work with old (i.e. libGLcore) xserver:

- made unbindContext a noop

- extensions:

  GLX_SGI_make_current_read
  GLX_EXT_texture_from_pixmap
  GLX_MESA_copy_sub_buffer

also clean header inclusion after code movement

Add DRI2 direct rendering support to libGL and add DRI2 client side
protocol code.  Extend the GLX 1.3 create drawable functions in
glx_pbuffer.c to call into the DRI driver when possible.

Introduce __DRIconfig, opaque struct that represents a DRI driver
configuration.  Get's rid of the open coded __GLcontextModes in the
DRI driver interface and the context modes create and destroy
functions that the loader was requires to provide.  glcore.h is no
longer part of the DRI driver interface.  The DRI config is GL binding
agnostic, that is, not specific to GLX, EGL or other bindings.

The core API is now also an extension, and the driver exports a list
of extensions as the symbol __driDriverExtensions, which the loader
must dlsym() for.  The list of extension will always include the DRI
core extension, which allows creating and manipulating DRI screens,
drawables and contexts.  The DRI legacy extension, when available,
provides alternative entry points for creating the DRI objects that
work with the XF86DRI infrastructure.

Change DRI2 client code to not use drm drawables or contexts.  We
never used drm_drawable_t's and the only use for drm_context_t was as
a unique identifier when taking the lock.  We now just allocate a
unique lock ID out of the DRILock sarea block.  Once we get rid of the
lock entirely, we can drop this hack.

Change the interface between dri_util.c and the drivers, so that the
drivers now export the DriverAPI struct as driDriverAPI instead of the
InitScreen entry point.  This lets us avoid dlsym()'ing for the DRI2
init screen function to see if DRI2 is supported by the driver.

to check whether oldGC is used for direct rendering in
function MakeContextCurrent. However it is possible
oldGC->driContext is already freed. fix bug #14926.

This will be shared between dri and dri2 code.

Spotted by Chris Taylor.

Also drop isDirect flag; if gc->driContext is non-NULL, it's direct.

Temporarily rename the __DRIscreen member to __driScreen.  Eventually,
we'll move that into __GLXDRIscreen and only access it in dri_glx.c.

We avoid leaking the symbols and will be able to replace them with
DRI2 implementation later on.

This patch moves __DRIdisplayPrivateRec definition into dri_glx.c and
let's dri_glx.c allocate the __DRIdisplay struct pointer to from
__GLXdisplayPrivate.

A small step towards moving more of the dri functionality into dri_glx.c.

No need to jump through hoops to track __DRIdrivers and avoid dlopening the
same .so more than twice, dlopen() does this internally.  Besides, we
were already bypassing this and dlopening drivers for each screen,
whether or not they were already dlopened.

Move a lot of code over from glx_ext.c.

The old version just set GLX_DRAWABLE_TYPE to GLX_WINDOW_BIT for
configs received through glXGetVisualConfigs and to
GLX_WINDOW_BIT | GLX_PIXMAP_BIT for configs received as FBConfigs.
The X server needs to send this info, but keep the workaround for now.

Fixes #12835.