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From: Chris Metcalf on 25 Jun 2010 17:20
This code is used in other places in our system than in Linux, so
to share it we now implement it as an inline function in our low-level
<arch> headers, and instantiate it in one file in Linux's arch/tile/lib.
The file is now cacheflush.c and is C code rather than the strangely-named
and assembler-implemented __invalidate_icache.S.

Signed-off-by: Chris Metcalf <cmetcalf(a)tilera.com>
---
arch/tile/include/arch/icache.h | 94 +++++++++++++++++++++++++++++++
arch/tile/include/asm/cacheflush.h | 9 +--
arch/tile/lib/Makefile | 2 +-
arch/tile/lib/__invalidate_icache.S | 106 -----------------------------------
arch/tile/lib/cacheflush.c | 23 ++++++++
5 files changed, 120 insertions(+), 114 deletions(-)
create mode 100644 arch/tile/include/arch/icache.h
delete mode 100644 arch/tile/lib/__invalidate_icache.S
create mode 100644 arch/tile/lib/cacheflush.c

diff --git a/arch/tile/include/arch/icache.h b/arch/tile/include/arch/icache.h
new file mode 100644
index 0000000..5c87c90
--- /dev/null
+++ b/arch/tile/include/arch/icache.h
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2010 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.
+ *
+ */
+
+/**
+ * @file
+ *
+ * Support for invalidating bytes in the instruction
+ */
+
+#ifndef __ARCH_ICACHE_H__
+#define __ARCH_ICACHE_H__
+
+#include <arch/chip.h>
+
+
+/**
+ * Invalidate the instruction cache for the given range of memory.
+ *
+ * @param addr The start of memory to be invalidated.
+ * @param size The number of bytes to be invalidated.
+ * @param page_size The system's page size, typically the PAGE_SIZE constant
+ * in sys/page.h. This value must be a power of two no larger
+ * than the page containing the code to be invalidated. If the value
+ * is smaller than the actual page size, this function will still
+ * work, but may run slower than necessary.
+ */
+static __inline void
+invalidate_icache(const void* addr, unsigned long size,
+ unsigned long page_size)
+{
+ const unsigned long cache_way_size =
+ CHIP_L1I_CACHE_SIZE() / CHIP_L1I_ASSOC();
+ unsigned long max_useful_size;
+ const char* start, *end;
+ long num_passes;
+
+ if (__builtin_expect(size == 0, 0))
+ return;
+
+#ifdef __tilegx__
+ /* Limit the number of bytes visited to avoid redundant iterations. */
+ max_useful_size = (page_size < cache_way_size) ? page_size : cache_way_size;
+
+ /* No PA aliasing is possible, so one pass always suffices. */
+ num_passes = 1;
+#else
+ /* Limit the number of bytes visited to avoid redundant iterations. */
+ max_useful_size = cache_way_size;
+
+ /*
+ * Compute how many passes we need (we'll treat 0 as if it were 1).
+ * This works because we know the page size is a power of two.
+ */
+ num_passes = cache_way_size >> __builtin_ctzl(page_size);
+#endif
+
+ if (__builtin_expect(size > max_useful_size, 0))
+ size = max_useful_size;
+
+ /* Locate the first and last bytes to be invalidated. */
+ start = (const char *)((unsigned long)addr & -CHIP_L1I_LINE_SIZE());
+ end = (const char*)addr + size - 1;
+
+ __insn_mf();
+
+ do
+ {
+ const char* p;
+
+ for (p = start; p <= end; p += CHIP_L1I_LINE_SIZE())
+ __insn_icoh(p);
+
+ start += page_size;
+ end += page_size;
+ }
+ while (--num_passes > 0);
+
+ __insn_drain();
+}
+
+
+#endif /* __ARCH_ICACHE_H__ */
diff --git a/arch/tile/include/asm/cacheflush.h b/arch/tile/include/asm/cacheflush.h
index 7e2096a..c5741da 100644
--- a/arch/tile/include/asm/cacheflush.h
+++ b/arch/tile/include/asm/cacheflush.h
@@ -21,6 +21,7 @@
#include <linux/mm.h>
#include <linux/cache.h>
#include <asm/system.h>
+#include <arch/icache.h>

/* Caches are physically-indexed and so don't need special treatment */
#define flush_cache_all() do { } while (0)
@@ -37,14 +38,8 @@
#define flush_icache_page(vma, pg) do { } while (0)
#define flush_icache_user_range(vma, pg, adr, len) do { } while (0)

-/* See "arch/tile/lib/__invalidate_icache.S". */
-extern void __invalidate_icache(unsigned long start, unsigned long size);
-
/* Flush the icache just on this cpu */
-static inline void __flush_icache_range(unsigned long start, unsigned long end)
-{
- __invalidate_icache(start, end - start);
-}
+extern void __flush_icache_range(unsigned long start, unsigned long end);

/* Flush the entire icache on this cpu. */
#define __flush_icache() __flush_icache_range(0, CHIP_L1I_CACHE_SIZE())
diff --git a/arch/tile/lib/Makefile b/arch/tile/lib/Makefile
index ea9c209..438af38 100644
--- a/arch/tile/lib/Makefile
+++ b/arch/tile/lib/Makefile
@@ -2,7 +2,7 @@
# Makefile for TILE-specific library files..
#

-lib-y = checksum.o cpumask.o delay.o __invalidate_icache.o \
+lib-y = cacheflush.o checksum.o cpumask.o delay.o \
mb_incoherent.o uaccess.o \
memcpy_$(BITS).o memchr_$(BITS).o memmove_$(BITS).o memset_$(BITS).o \
strchr_$(BITS).o strlen_$(BITS).o
diff --git a/arch/tile/lib/__invalidate_icache.S b/arch/tile/lib/__invalidate_icache.S
deleted file mode 100644
index 92e7050..0000000
--- a/arch/tile/lib/__invalidate_icache.S
+++ /dev/null
@@ -1,106 +0,0 @@
-/*
- * Copyright 2010 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.
- * A routine for synchronizing the instruction and data caches.
- * Useful for self-modifying code.
- *
- * r0 holds the buffer address
- * r1 holds the size in bytes
- */
-
-#include <arch/chip.h>
-#include <feedback.h>
-
-#if defined(__NEWLIB__) || defined(__BME__)
-#include <sys/page.h>
-#else
-#include <asm/page.h>
-#endif
-
-#ifdef __tilegx__
-/* Share code among Tile family chips but adjust opcodes appropriately. */
-#define slt cmpltu
-#define bbst blbst
-#define bnezt bnzt
-#endif
-
-#if defined(__tilegx__) && __SIZEOF_POINTER__ == 4
-/* Force 32-bit ops so pointers wrap around appropriately. */
-#define ADD_PTR addx
-#define ADDI_PTR addxi
-#else
-#define ADD_PTR add
-#define ADDI_PTR addi
-#endif
-
- .section .text.__invalidate_icache, "ax"
- .global __invalidate_icache
- .type __invalidate_icache,@function
- .hidden __invalidate_icache
- .align 8
-__invalidate_icache:
- FEEDBACK_ENTER(__invalidate_icache)
- {
- ADD_PTR r1, r0, r1 /* end of buffer */
- blez r1, .Lexit /* skip out if size <= 0 */
- }
- {
- ADDI_PTR r1, r1, -1 /* point to last byte to flush */
- andi r0, r0, -CHIP_L1I_LINE_SIZE() /* align to cache-line size */
- }
- {
- andi r1, r1, -CHIP_L1I_LINE_SIZE() /* last cache line to flush */
- mf
- }
-#if CHIP_L1I_CACHE_SIZE() > PAGE_SIZE
- {
- moveli r4, CHIP_L1I_CACHE_SIZE() / PAGE_SIZE /* loop counter */
- move r2, r0 /* remember starting address */
- }
-#endif
- drain
- {
- slt r3, r0, r1 /* set up loop invariant */
-#if CHIP_L1I_CACHE_SIZE() > PAGE_SIZE
- moveli r6, PAGE_SIZE
-#endif
- }
-.Lentry:
- {
- icoh r0
- ADDI_PTR r0, r0, CHIP_L1I_LINE_SIZE() /* advance buffer */
- }
- {
- slt r3, r0, r1 /* check if buffer < buffer + size */
- bbst r3, .Lentry /* loop if buffer < buffer + size */
- }
-#if CHIP_L1I_CACHE_SIZE() > PAGE_SIZE
- {
- ADD_PTR r2, r2, r6
- ADD_PTR r1, r1, r6
- }
- {
- move r0, r2
- addi r4, r4, -1
- }
- {
- slt r3, r0, r1 /* set up loop invariant */
- bnezt r4, .Lentry
- }
-#endif
- drain
-.Lexit:
- jrp lr
-
-.Lend___invalidate_icache:
- .size __invalidate_icache, \
- .Lend___invalidate_icache - __invalidate_icache
diff --git a/arch/tile/lib/cacheflush.c b/arch/tile/lib/cacheflush.c
new file mode 100644
index 0000000..11b6164
--- /dev/null
+++ b/arch/tile/lib/cacheflush.c
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2010 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 <asm/page.h>
+#include <asm/cacheflush.h>
+#include <arch/icache.h>
+
+
+void __flush_icache_range(unsigned long start, unsigned long end)
+{
+ invalidate_icache((const void *)start, end - start, PAGE_SIZE);
+}
--
1.6.5.2

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Pages: 1
Prev: [PATCH] arch/tile: Fix bug in support for atomic64_xx() ops.
Next: [PATCH] arch/tile: Shrink the tile-opcode files considerably.