powerpc: Merge enough to start building in arch/powerpc.

This creates the directory structure under arch/powerpc and a bunch
of Kconfig files.  It does a first-cut merge of arch/powerpc/mm,
arch/powerpc/lib and arch/powerpc/platforms/powermac.  This is enough
to build a 32-bit powermac kernel with ARCH=powerpc.

For now we are getting some unmerged files from arch/ppc/kernel and
arch/ppc/syslib, or arch/ppc64/kernel.  This makes some minor changes
to files in those directories and files outside arch/powerpc.

The boot directory is still not merged.  That's going to be interesting.

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

1 files changed, 197 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
new file mode 100644
index 00000000000..12cb90bc209
--- /dev/null
+++ b/arch/powerpc/kernel/vector.S
@@ -0,0 +1,197 @@
+#include <linux/config.h>
+#include <asm/ppc_asm.h>
+#include <asm/processor.h>
+
+/*
+ * The routines below are in assembler so we can closely control the
+ * usage of floating-point registers.  These routines must be called
+ * with preempt disabled.
+ */
+#ifdef CONFIG_PPC32
+	.data
+fpzero:
+	.long	0
+fpone:
+	.long	0x3f800000	/* 1.0 in single-precision FP */
+fphalf:
+	.long	0x3f000000	/* 0.5 in single-precision FP */
+
+#define LDCONST(fr, name)	\
+	lis	r11,name@ha;	\
+	lfs	fr,name@l(r11)
+#else
+
+	.section ".toc","aw"
+fpzero:
+	.tc	FD_0_0[TC],0
+fpone:
+	.tc	FD_3ff00000_0[TC],0x3ff0000000000000	/* 1.0 */
+fphalf:
+	.tc	FD_3fe00000_0[TC],0x3fe0000000000000	/* 0.5 */
+
+#define LDCONST(fr, name)	\
+	lfd	fr,name@toc(r2)
+#endif
+
+	.text
+/*
+ * Internal routine to enable floating point and set FPSCR to 0.
+ * Don't call it from C; it doesn't use the normal calling convention.
+ */
+fpenable:
+#ifdef CONFIG_PPC32
+	stwu	r1,-64(r1)
+#else
+	stdu	r1,-64(r1)
+#endif
+	mfmsr	r10
+	ori	r11,r10,MSR_FP
+	mtmsr	r11
+	isync
+	stfd	fr0,24(r1)
+	stfd	fr1,16(r1)
+	stfd	fr31,8(r1)
+	LDCONST(fr1, fpzero)
+	mffs	fr31
+	mtfsf	0xff,fr1
+	blr
+
+fpdisable:
+	mtlr	r12
+	mtfsf	0xff,fr31
+	lfd	fr31,8(r1)
+	lfd	fr1,16(r1)
+	lfd	fr0,24(r1)
+	mtmsr	r10
+	isync
+	addi	r1,r1,64
+	blr
+
+/*
+ * Vector add, floating point.
+ */
+_GLOBAL(vaddfp)
+	mflr	r12
+	bl	fpenable
+	li	r0,4
+	mtctr	r0
+	li	r6,0
+1:	lfsx	fr0,r4,r6
+	lfsx	fr1,r5,r6
+	fadds	fr0,fr0,fr1
+	stfsx	fr0,r3,r6
+	addi	r6,r6,4
+	bdnz	1b
+	b	fpdisable
+
+/*
+ * Vector subtract, floating point.
+ */
+_GLOBAL(vsubfp)
+	mflr	r12
+	bl	fpenable
+	li	r0,4
+	mtctr	r0
+	li	r6,0
+1:	lfsx	fr0,r4,r6
+	lfsx	fr1,r5,r6
+	fsubs	fr0,fr0,fr1
+	stfsx	fr0,r3,r6
+	addi	r6,r6,4
+	bdnz	1b
+	b	fpdisable
+
+/*
+ * Vector multiply and add, floating point.
+ */
+_GLOBAL(vmaddfp)
+	mflr	r12
+	bl	fpenable
+	stfd	fr2,32(r1)
+	li	r0,4
+	mtctr	r0
+	li	r7,0
+1:	lfsx	fr0,r4,r7
+	lfsx	fr1,r5,r7
+	lfsx	fr2,r6,r7
+	fmadds	fr0,fr0,fr2,fr1
+	stfsx	fr0,r3,r7
+	addi	r7,r7,4
+	bdnz	1b
+	lfd	fr2,32(r1)
+	b	fpdisable
+
+/*
+ * Vector negative multiply and subtract, floating point.
+ */
+_GLOBAL(vnmsubfp)
+	mflr	r12
+	bl	fpenable
+	stfd	fr2,32(r1)
+	li	r0,4
+	mtctr	r0
+	li	r7,0
+1:	lfsx	fr0,r4,r7
+	lfsx	fr1,r5,r7
+	lfsx	fr2,r6,r7
+	fnmsubs	fr0,fr0,fr2,fr1
+	stfsx	fr0,r3,r7
+	addi	r7,r7,4
+	bdnz	1b
+	lfd	fr2,32(r1)
+	b	fpdisable
+
+/*
+ * Vector reciprocal estimate.  We just compute 1.0/x.
+ * r3 -> destination, r4 -> source.
+ */
+_GLOBAL(vrefp)
+	mflr	r12
+	bl	fpenable
+	li	r0,4
+	LDCONST(fr1, fpone)
+	mtctr	r0
+	li	r6,0
+1:	lfsx	fr0,r4,r6
+	fdivs	fr0,fr1,fr0
+	stfsx	fr0,r3,r6
+	addi	r6,r6,4
+	bdnz	1b
+	b	fpdisable
+
+/*
+ * Vector reciprocal square-root estimate, floating point.
+ * We use the frsqrte instruction for the initial estimate followed
+ * by 2 iterations of Newton-Raphson to get sufficient accuracy.
+ * r3 -> destination, r4 -> source.
+ */
+_GLOBAL(vrsqrtefp)
+	mflr	r12
+	bl	fpenable
+	stfd	fr2,32(r1)
+	stfd	fr3,40(r1)
+	stfd	fr4,48(r1)
+	stfd	fr5,56(r1)
+	li	r0,4
+	LDCONST(fr4, fpone)
+	LDCONST(fr5, fphalf)
+	mtctr	r0
+	li	r6,0
+1:	lfsx	fr0,r4,r6
+	frsqrte	fr1,fr0		/* r = frsqrte(s) */
+	fmuls	fr3,fr1,fr0	/* r * s */
+	fmuls	fr2,fr1,fr5	/* r * 0.5 */
+	fnmsubs	fr3,fr1,fr3,fr4	/* 1 - s * r * r */
+	fmadds	fr1,fr2,fr3,fr1	/* r = r + 0.5 * r * (1 - s * r * r) */
+	fmuls	fr3,fr1,fr0	/* r * s */
+	fmuls	fr2,fr1,fr5	/* r * 0.5 */
+	fnmsubs	fr3,fr1,fr3,fr4	/* 1 - s * r * r */
+	fmadds	fr1,fr2,fr3,fr1	/* r = r + 0.5 * r * (1 - s * r * r) */
+	stfsx	fr1,r3,r6
+	addi	r6,r6,4
+	bdnz	1b
+	lfd	fr5,56(r1)
+	lfd	fr4,48(r1)
+	lfd	fr3,40(r1)
+	lfd	fr2,32(r1)
+	b	fpdisable