Scott Wood 9d378dfac8 powerpc/booke64: Use SPRG7 for VDSO ... Previously SPRG3 was marked for use by both VDSO and critical interrupts (though critical interrupts were not fully implemented). In commit 8b64a9dfb0 ("powerpc/booke64: Use SPRG0/3 scratch for bolted TLB miss & crit int"), Mihai Caraman made an attempt to resolve this conflict by restoring the VDSO value early in the critical interrupt, but this has some issues: - It's incompatible with EXCEPTION_COMMON which restores r13 from the by-then-overwritten scratch (this cost me some debugging time). - It forces critical exceptions to be a special case handled differently from even machine check and debug level exceptions. - It didn't occur to me that it was possible to make this work at all (by doing a final "ld r13, PACA_EXCRIT+EX_R13(r13)") until after I made (most of) this patch. :-) It might be worth investigating using a load rather than SPRG on return from all exceptions (except TLB misses where the scratch never leaves the SPRG) -- it could save a few cycles. Until then, let's stick with SPRG for all exceptions. Since we cannot use SPRG4-7 for scratch without corrupting the state of a KVM guest, move VDSO to SPRG7 on book3e. Since neither SPRG4-7 nor critical interrupts exist on book3s, SPRG3 is still used for VDSO there. Signed-off-by: Scott Wood <scottwood@freescale.com> Cc: Mihai Caraman <mihai.caraman@freescale.com> Cc: Anton Blanchard <anton@samba.org> Cc: Paul Mackerras <paulus@samba.org> Cc: kvm-ppc@vger.kernel.org		2014-03-19 19:57:14 -05:00
..
.gitignore
cacheflush.S
datapage.S
getcpu.S	powerpc/booke64: Use SPRG7 for VDSO	2014-03-19 19:57:14 -05:00
gettimeofday.S
Makefile
note.S
sigtramp.S	powerpc: Wrong DWARF CFI in the kernel vdso for little-endian / ELFv2	2013-11-21 09:19:23 +11:00
vdso64_wrapper.S	powerpc: Use unstripped VDSO image for more accurate profiling data	2014-02-17 11:19:37 +11:00
vdso64.lds.S	powerpc: Add ability to build little endian kernels	2013-10-11 16:48:56 +11:00