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 000000000000..3fab9a6a2bbe
--- /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