2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
19 * Support for invalidating bytes in the instruction cache.
22 #ifndef __ARCH_ICACHE_H__
23 #define __ARCH_ICACHE_H__
25 #include <arch/chip.h>
29 * Invalidate the instruction cache for the given range of memory.
31 * @param addr The start of memory to be invalidated.
32 * @param size The number of bytes to be invalidated.
33 * @param page_size The system's page size, e.g. getpagesize() in userspace.
34 * This value must be a power of two no larger than the page containing
35 * the code to be invalidated. If the value is smaller than the actual page
36 * size, this function will still work, but may run slower than necessary.
39 invalidate_icache(const void* addr, unsigned long size,
40 unsigned long page_size)
42 const unsigned long cache_way_size =
43 CHIP_L1I_CACHE_SIZE() / CHIP_L1I_ASSOC();
44 unsigned long max_useful_size;
45 const char* start, *end;
48 if (__builtin_expect(size == 0, 0))
52 /* Limit the number of bytes visited to avoid redundant iterations. */
53 max_useful_size = (page_size < cache_way_size) ? page_size : cache_way_size;
55 /* No PA aliasing is possible, so one pass always suffices. */
58 /* Limit the number of bytes visited to avoid redundant iterations. */
59 max_useful_size = cache_way_size;
62 * Compute how many passes we need (we'll treat 0 as if it were 1).
63 * This works because we know the page size is a power of two.
65 num_passes = cache_way_size >> __builtin_ctzl(page_size);
68 if (__builtin_expect(size > max_useful_size, 0))
69 size = max_useful_size;
71 /* Locate the first and last bytes to be invalidated. */
72 start = (const char *)((unsigned long)addr & -CHIP_L1I_LINE_SIZE());
73 end = (const char*)addr + size - 1;
81 for (p = start; p <= end; p += CHIP_L1I_LINE_SIZE())
87 while (--num_passes > 0);
93 #endif /* __ARCH_ICACHE_H__ */