[POWERPC] 64bit FPSCR support

Forthcoming machines will extend the FPSCR to 64 bits.  We already
had a 64-bit save area for the FPSCR, but we need to use a new form
of the mtfsf instruction.  Fortunately this new form is decoded as
an ordinary mtfsf by existing 64-bit processors.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/include/asm-powerpc/reg.h b/include/asm-powerpc/reg.h
index 3779b21a7c71..bfc7dc14ffcc 100644
--- a/include/asm-powerpc/reg.h
+++ b/include/asm-powerpc/reg.h
@@ -499,6 +499,19 @@
 #define MMCR0_PMC2_LOADMISSTIME 0x5
 #endif
 
+/*
+ * An mtfsf instruction with the L bit set. On CPUs that support this a
+ * full 64bits of FPSCR is restored and on other CPUs it is ignored.
+ *
+ * Until binutils gets the new form of mtfsf, hardwire the instruction.
+ */
+#ifdef CONFIG_PPC64
+#define MTFSF_L(REG) \
+        .long (0xfc00058e | ((0xff) << 17) | ((REG) << 11) | (1 << 25))
+#else
+#define MTFSF_L(REG)    mtfsf   0xff, (REG)
+#endif
+
 /* Processor Version Register (PVR) field extraction */
 
 #define PVR_VER(pvr)    (((pvr) >>  16) & 0xFFFF)       /* Version field */