[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>
diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
index 340730f..01f7120 100644
--- a/arch/powerpc/kernel/fpu.S
+++ b/arch/powerpc/kernel/fpu.S
@@ -72,7 +72,7 @@
std r12,_MSR(r1)
#endif
lfd fr0,THREAD_FPSCR(r5)
- mtfsf 0xff,fr0
+ MTFSF_L(fr0)
REST_32FPRS(0, r5)
#ifndef CONFIG_SMP
subi r4,r5,THREAD
@@ -127,7 +127,7 @@
_GLOBAL(cvt_fd)
lfd 0,THREAD_FPSCR(r5) /* load up fpscr value */
- mtfsf 0xff,0
+ MTFSF_L(0)
lfs 0,0(r3)
stfd 0,0(r4)
mffs 0
@@ -136,7 +136,7 @@
_GLOBAL(cvt_df)
lfd 0,THREAD_FPSCR(r5) /* load up fpscr value */
- mtfsf 0xff,0
+ MTFSF_L(0)
lfd 0,0(r3)
stfs 0,0(r4)
mffs 0
diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
index 66b3d03..9416b4a 100644
--- a/arch/powerpc/kernel/vector.S
+++ b/arch/powerpc/kernel/vector.S
@@ -53,12 +53,12 @@
stfd fr31,8(r1)
LDCONST(fr1, fpzero)
mffs fr31
- mtfsf 0xff,fr1
+ MTFSF_L(fr1)
blr
fpdisable:
mtlr r12
- mtfsf 0xff,fr31
+ MTFSF_L(fr31)
lfd fr31,8(r1)
lfd fr1,16(r1)
lfd fr0,24(r1)
diff --git a/include/asm-powerpc/reg.h b/include/asm-powerpc/reg.h
index 3779b21..bfc7dc1 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 */