arch/tile: finish enabling support for TILE-Gx 64-bit chip

This support was partially present in the existing code (look for
"__tilegx__" ifdefs) but with this change you can build a working
kernel using the TILE-Gx toolchain and ARCH=tilegx.

Most of these files are new, generally adding a foo_64.c file
where previously there was just a foo_32.c file.

The ARCH=tilegx directive redirects to arch/tile, not arch/tilegx,
using the existing SRCARCH mechanism in the top-level Makefile.

Changes to existing files:

- <asm/bitops.h> and <asm/bitops_32.h> changed to factor the
  include of <asm-generic/bitops/non-atomic.h> in the common header.

- <asm/compat.h> and arch/tile/kernel/compat.c changed to remove
  the "const" markers I had put on compat_sys_execve() when trying
  to match some recent similar changes to the non-compat execve.
  It turns out the compat version wasn't "upgraded" to use const.

- <asm/opcode-tile_64.h> and <asm/opcode_constants_64.h> were
  previously included accidentally, with the 32-bit contents.  Now
  they have the proper 64-bit contents.

Finally, I had to hack the existing hacky drivers/input/input-compat.h
to add yet another "#ifdef" for INPUT_COMPAT_TEST (same as x86_64).

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> [drivers/input]

1 files changed, 220 insertions, 0 deletions

diff --git a/arch/tile/lib/memcpy_64.c b/arch/tile/lib/memcpy_64.c
new file mode 100644
index 00000000000..3fab9a6a2bb
--- /dev/null
+++ b/arch/tile/lib/memcpy_64.c
@@ -0,0 +1,220 @@
+/*
+ * Copyright 2011 Tilera Corporation. 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, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/module.h>
+#define __memcpy memcpy
+/* EXPORT_SYMBOL() is in arch/tile/lib/exports.c since this should be asm. */
+
+/* Must be 8 bytes in size. */
+#define word_t uint64_t
+
+#if CHIP_L2_LINE_SIZE() != 64 && CHIP_L2_LINE_SIZE() != 128
+#error "Assumes 64 or 128 byte line size"
+#endif
+
+/* How many cache lines ahead should we prefetch? */
+#define PREFETCH_LINES_AHEAD 3
+
+/*
+ * Provide "base versions" of load and store for the normal code path.
+ * The kernel provides other versions for userspace copies.
+ */
+#define ST(p, v) (*(p) = (v))
+#define LD(p) (*(p))
+
+#ifndef USERCOPY_FUNC
+#define ST1 ST
+#define ST2 ST
+#define ST4 ST
+#define ST8 ST
+#define LD1 LD
+#define LD2 LD
+#define LD4 LD
+#define LD8 LD
+#define RETVAL dstv
+void *memcpy(void *__restrict dstv, const void *__restrict srcv, size_t n)
+#else
+/*
+ * Special kernel version will provide implementation of the LDn/STn
+ * macros to return a count of uncopied bytes due to mm fault.
+ */
+#define RETVAL 0
+int USERCOPY_FUNC(void *__restrict dstv, const void *__restrict srcv, size_t n)
+#endif
+{
+	char *__restrict dst1 = (char *)dstv;
+	const char *__restrict src1 = (const char *)srcv;
+	const char *__restrict src1_end;
+	const char *__restrict prefetch;
+	word_t *__restrict dst8;    /* 8-byte pointer to destination memory. */
+	word_t final; /* Final bytes to write to trailing word, if any */
+	long i;
+
+	if (n < 16) {
+		for (; n; n--)
+			ST1(dst1++, LD1(src1++));
+		return RETVAL;
+	}
+
+	/*
+	 * Locate the end of source memory we will copy.  Don't
+	 * prefetch past this.
+	 */
+	src1_end = src1 + n - 1;
+
+	/* Prefetch ahead a few cache lines, but not past the end. */
+	prefetch = src1;
+	for (i = 0; i < PREFETCH_LINES_AHEAD; i++) {
+		__insn_prefetch(prefetch);
+		prefetch += CHIP_L2_LINE_SIZE();
+		prefetch = (prefetch > src1_end) ? prefetch : src1;
+	}
+
+	/* Copy bytes until dst is word-aligned. */
+	for (; (uintptr_t)dst1 & (sizeof(word_t) - 1); n--)
+		ST1(dst1++, LD1(src1++));
+
+	/* 8-byte pointer to destination memory. */
+	dst8 = (word_t *)dst1;
+
+	if (__builtin_expect((uintptr_t)src1 & (sizeof(word_t) - 1), 0)) {
+		/*
+		 * Misaligned copy.  Copy 8 bytes at a time, but don't
+		 * bother with other fanciness.
+		 *
+		 * TODO: Consider prefetching and using wh64 as well.
+		 */
+
+		/* Create an aligned src8. */
+		const word_t *__restrict src8 =
+			(const word_t *)((uintptr_t)src1 & -sizeof(word_t));
+		word_t b;
+
+		word_t a = LD8(src8++);
+		for (; n >= sizeof(word_t); n -= sizeof(word_t)) {
+			b = LD8(src8++);
+			a = __insn_dblalign(a, b, src1);
+			ST8(dst8++, a);
+			a = b;
+		}
+
+		if (n == 0)
+			return RETVAL;
+
+		b = ((const char *)src8 <= src1_end) ? *src8 : 0;
+
+		/*
+		 * Final source bytes to write to trailing partial
+		 * word, if any.
+		 */
+		final = __insn_dblalign(a, b, src1);
+	} else {
+		/* Aligned copy. */
+
+		const word_t* __restrict src8 = (const word_t *)src1;
+
+		/* src8 and dst8 are both word-aligned. */
+		if (n >= CHIP_L2_LINE_SIZE()) {
+			/* Copy until 'dst' is cache-line-aligned. */
+			for (; (uintptr_t)dst8 & (CHIP_L2_LINE_SIZE() - 1);
+			     n -= sizeof(word_t))
+				ST8(dst8++, LD8(src8++));
+
+			for (; n >= CHIP_L2_LINE_SIZE(); ) {
+				__insn_wh64(dst8);
+
+				/*
+				 * Prefetch and advance to next line
+				 * to prefetch, but don't go past the end
+				 */
+				__insn_prefetch(prefetch);
+				prefetch += CHIP_L2_LINE_SIZE();
+				prefetch = (prefetch > src1_end) ? prefetch :
+					(const char *)src8;
+
+				/*
+				 * Copy an entire cache line.  Manually
+				 * unrolled to avoid idiosyncracies of
+				 * compiler unrolling.
+				 */
+#define COPY_WORD(offset) ({ ST8(dst8+offset, LD8(src8+offset)); n -= 8; })
+				COPY_WORD(0);
+				COPY_WORD(1);
+				COPY_WORD(2);
+				COPY_WORD(3);
+				COPY_WORD(4);
+				COPY_WORD(5);
+				COPY_WORD(6);
+				COPY_WORD(7);
+#if CHIP_L2_LINE_SIZE() == 128
+				COPY_WORD(8);
+				COPY_WORD(9);
+				COPY_WORD(10);
+				COPY_WORD(11);
+				COPY_WORD(12);
+				COPY_WORD(13);
+				COPY_WORD(14);
+				COPY_WORD(15);
+#elif CHIP_L2_LINE_SIZE() != 64
+# error Fix code that assumes particular L2 cache line sizes
+#endif
+
+				dst8 += CHIP_L2_LINE_SIZE() / sizeof(word_t);
+				src8 += CHIP_L2_LINE_SIZE() / sizeof(word_t);
+			}
+		}
+
+		for (; n >= sizeof(word_t); n -= sizeof(word_t))
+			ST8(dst8++, LD8(src8++));
+
+		if (__builtin_expect(n == 0, 1))
+			return RETVAL;
+
+		final = LD8(src8);
+	}
+
+	/* n != 0 if we get here.  Write out any trailing bytes. */
+	dst1 = (char *)dst8;
+	if (n & 4) {
+		ST4((uint32_t *)dst1, final);
+		dst1 += 4;
+		final >>= 32;
+		n &= 3;
+	}
+	if (n & 2) {
+		ST2((uint16_t *)dst1, final);
+		dst1 += 2;
+		final >>= 16;
+		n &= 1;
+	}
+	if (n)
+		ST1((uint8_t *)dst1, final);
+
+	return RETVAL;
+}
+
+
+#ifdef USERCOPY_FUNC
+#undef ST1
+#undef ST2
+#undef ST4
+#undef ST8
+#undef LD1
+#undef LD2
+#undef LD4
+#undef LD8
+#undef USERCOPY_FUNC
+#endif