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authorMichael Neuling <mikey@neuling.org>2013-08-26 03:55:57 (GMT)
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-08-27 05:05:22 (GMT)
commitbc683a7e51c5c838bc74316125bebec92af74f12 (patch)
tree5e747e76bff1b853ec1a97dbb2fdb37f89d76460 /arch/powerpc/kernel/traps.c
parent3f1f4311881b330a7b5429dd101e676df191b159 (diff)
downloadlinux-fsl-qoriq-bc683a7e51c5c838bc74316125bebec92af74f12.tar.xz
powerpc: Cleanup handling of the DSCR bit in the FSCR register
As suggested by paulus we can simplify the Data Stream Control Register (DSCR) Facility Status and Control Register (FSCR) handling. Firstly, we simplify the asm by using a rldimi. Secondly, we now use the FSCR only to control the DSCR facility, rather than both the FSCR and HFSCR. Users will see no functional change from this but will get a minor speedup as they will trap into the kernel only once (rather than twice) when they first touch the DSCR. Also, this changes removes a bunch of ugly FTR_SECTION code. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/traps.c')
-rw-r--r--arch/powerpc/kernel/traps.c7
1 files changed, 2 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 529a932..f783c93 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1342,13 +1342,10 @@ void facility_unavailable_exception(struct pt_regs *regs)
if (status == FSCR_DSCR_LG) {
/* User is acessing the DSCR. Set the inherit bit and allow
* the user to set it directly in future by setting via the
- * H/FSCR DSCR bit.
+ * FSCR DSCR bit. We always leave HFSCR DSCR set.
*/
current->thread.dscr_inherit = 1;
- if (hv)
- mtspr(SPRN_HFSCR, value | HFSCR_DSCR);
- else
- mtspr(SPRN_FSCR, value | FSCR_DSCR);
+ mtspr(SPRN_FSCR, value | FSCR_DSCR);
return;
}