mesa: Resurrect SPARC asm code.

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>

1 files changed, 2 insertions, 36 deletions

diff --git a/src/mesa/sparc/sparc.c b/src/mesa/sparc/sparc.c
index 84e8ac6723..3bde98e34b 100644
--- a/src/mesa/sparc/sparc.c
+++ b/src/mesa/sparc/sparc.c
@@ -109,10 +109,10 @@ void _mesa_init_all_sparc_transform_asm(void)
    ASSIGN_XFORM_GROUP(sparc, 2)
    ASSIGN_XFORM_GROUP(sparc, 3)
    ASSIGN_XFORM_GROUP(sparc, 4)
-
+#if 0
    _mesa_clip_tab[4] = _mesa_sparc_cliptest_points4;
    _mesa_clip_np_tab[4] = _mesa_sparc_cliptest_points4_np;
-
+#endif
 #if 0
    /* disable these too.  See bug 673938 */
    _mesa_normal_tab[NORM_TRANSFORM | NORM_NORMALIZE] =
@@ -140,38 +140,4 @@ void _mesa_init_all_sparc_transform_asm(void)
 #endif
 }
 
-extern unsigned int _mesa_sparc_glapi_begin;
-extern unsigned int _mesa_sparc_glapi_end;
-extern void __glapi_sparc_icache_flush(unsigned int *);
-
-#endif /* USE_SPARC_ASM */
-
-
-void _mesa_init_sparc_glapi_relocs(void)
-{
-#ifdef USE_SPARC_ASM
-	unsigned int *insn_ptr, *end_ptr;
-	unsigned long disp_addr;
-
-	insn_ptr = &_mesa_sparc_glapi_begin;
-	end_ptr = &_mesa_sparc_glapi_end;
-	disp_addr = (unsigned long) &_glapi_Dispatch;
-
-	while (insn_ptr < end_ptr) {
-#ifdef __arch64__
-		insn_ptr[0] |= (disp_addr >> (32 + 10));
-		insn_ptr[1] |= ((disp_addr & 0xffffffff) >> 10);
-		__glapi_sparc_icache_flush(&insn_ptr[0]);
-		insn_ptr[2] |= ((disp_addr >> 32) & ((1 << 10) - 1));
-		insn_ptr[3] |= (disp_addr & ((1 << 10) - 1));
-		__glapi_sparc_icache_flush(&insn_ptr[2]);
-		insn_ptr += 11;
-#else
-		insn_ptr[0] |= (disp_addr >> 10);
-		insn_ptr[1] |= (disp_addr & ((1 << 10) - 1));
-		__glapi_sparc_icache_flush(&insn_ptr[0]);
-		insn_ptr += 5;
-#endif
-	}
 #endif /* USE_SPARC_ASM */
-}