From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@ppc970.osdl.org>
Date: Sat, 16 Apr 2005 15:20:36 -0700
Subject: Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
---
 drivers/md/raid6altivec.uc | 122 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 122 insertions(+)
 create mode 100644 drivers/md/raid6altivec.uc

(limited to 'drivers/md/raid6altivec.uc')

diff --git a/drivers/md/raid6altivec.uc b/drivers/md/raid6altivec.uc
new file mode 100644
index 00000000000..1de8f030eee
--- /dev/null
+++ b/drivers/md/raid6altivec.uc
@@ -0,0 +1,122 @@
+/* -*- linux-c -*- ------------------------------------------------------- *
+ *
+ *   Copyright 2002-2004 H. Peter Anvin - All Rights Reserved
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
+ *   Bostom MA 02111-1307, USA; either version 2 of the License, or
+ *   (at your option) any later version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * raid6altivec$#.c
+ *
+ * $#-way unrolled portable integer math RAID-6 instruction set
+ *
+ * This file is postprocessed using unroll.pl
+ *
+ * <benh> hpa: in process,
+ * you can just "steal" the vec unit with enable_kernel_altivec() (but
+ * bracked this with preempt_disable/enable or in a lock)
+ */
+
+#include "raid6.h"
+
+#ifdef CONFIG_ALTIVEC
+
+#include <altivec.h>
+#include <asm/system.h>
+#include <asm/cputable.h>
+
+/*
+ * This is the C data type to use
+ */
+
+typedef vector unsigned char unative_t;
+
+#define NBYTES(x) ((vector unsigned char) {x,x,x,x, x,x,x,x, x,x,x,x, x,x,x,x})
+#define NSIZE	sizeof(unative_t)
+
+/*
+ * The SHLBYTE() operation shifts each byte left by 1, *not*
+ * rolling over into the next byte
+ */
+static inline __attribute_const__ unative_t SHLBYTE(unative_t v)
+{
+	return vec_add(v,v);
+}
+
+/*
+ * The MASK() operation returns 0xFF in any byte for which the high
+ * bit is 1, 0x00 for any byte for which the high bit is 0.
+ */
+static inline __attribute_const__ unative_t MASK(unative_t v)
+{
+	unative_t zv = NBYTES(0);
+
+	/* vec_cmpgt returns a vector bool char; thus the need for the cast */
+	return (unative_t)vec_cmpgt(zv, v);
+}
+
+
+/* This is noinline to make damned sure that gcc doesn't move any of the
+   Altivec code around the enable/disable code */
+static void noinline
+raid6_altivec$#_gen_syndrome_real(int disks, size_t bytes, void **ptrs)
+{
+	u8 **dptr = (u8 **)ptrs;
+	u8 *p, *q;
+	int d, z, z0;
+
+	unative_t wd$$, wq$$, wp$$, w1$$, w2$$;
+	unative_t x1d = NBYTES(0x1d);
+
+	z0 = disks - 3;		/* Highest data disk */
+	p = dptr[z0+1];		/* XOR parity */
+	q = dptr[z0+2];		/* RS syndrome */
+
+	for ( d = 0 ; d < bytes ; d += NSIZE*$# ) {
+		wq$$ = wp$$ = *(unative_t *)&dptr[z0][d+$$*NSIZE];
+		for ( z = z0-1 ; z >= 0 ; z-- ) {
+			wd$$ = *(unative_t *)&dptr[z][d+$$*NSIZE];
+			wp$$ = vec_xor(wp$$, wd$$);
+			w2$$ = MASK(wq$$);
+			w1$$ = SHLBYTE(wq$$);
+			w2$$ = vec_and(w2$$, x1d);
+			w1$$ = vec_xor(w1$$, w2$$);
+			wq$$ = vec_xor(w1$$, wd$$);
+		}
+		*(unative_t *)&p[d+NSIZE*$$] = wp$$;
+		*(unative_t *)&q[d+NSIZE*$$] = wq$$;
+	}
+}
+
+static void raid6_altivec$#_gen_syndrome(int disks, size_t bytes, void **ptrs)
+{
+	preempt_disable();
+	enable_kernel_altivec();
+
+	raid6_altivec$#_gen_syndrome_real(disks, bytes, ptrs);
+
+	preempt_enable();
+}
+
+int raid6_have_altivec(void);
+#if $# == 1
+int raid6_have_altivec(void)
+{
+	/* This assumes either all CPUs have Altivec or none does */
+	return cpu_has_feature(CPU_FTR_ALTIVEC);
+}
+#endif
+
+const struct raid6_calls raid6_altivec$# = {
+	raid6_altivec$#_gen_syndrome,
+	raid6_have_altivec,
+	"altivecx$#",
+	0
+};
+
+#endif /* CONFIG_ALTIVEC */
-- 
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