1
linux/arch/tile/include/arch/icache.h
Chris Metcalf c78095bd8c arch/tile: Split the icache flush code off to a generic <arch> header.
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@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2010-07-06 13:41:46 -04:00

95 lines
2.6 KiB
C

/*
* 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__ */