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 000000000000..12cb90bc209c
--- /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