cacheasm.h

linux-2.6.15.6

#ifndef XTENSA_CACHEASM_H
#define XTENSA_CACHEASM_H

/*
 * THIS FILE IS GENERATED -- DO NOT MODIFY BY HAND
 *
 * include/asm-xtensa/xtensa/cacheasm.h -- assembler-specific cache
 * related definitions that depend on CORE configuration.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2002 Tensilica Inc.
 */


#include <xtensa/coreasm.h>


/*
 *  This header file defines assembler macros of the form:
 *	<x>cache_<func>
 *  where <x> is 'i' or 'd' for instruction and data caches,
 *  and <func> indicates the function of the macro.
 *
 *  The following functions <func> are defined,
 *  and apply only to the specified cache (I or D):
 *
 *  reset
 *	Resets the cache.
 *
 *  sync
 *	Makes sure any previous cache instructions have been completed;
 *	ie. makes sure any previous cache control operations
 *	have had full effect and been synchronized to memory.
 *	Eg. any invalidate completed [so as not to generate a hit],
 *	any writebacks or other pipelined writes written to memory, etc.
 *
 *  invalidate_line		(single cache line)
 *  invalidate_region		(specified memory range)
 *  invalidate_all		(entire cache)
 *	Invalidates all cache entries that cache
 *	data from the specified memory range.
 *	NOTE: locked entries are not invalidated.
 *
 *  writeback_line		(single cache line)
 *  writeback_region		(specified memory range)
 *  writeback_all		(entire cache)
 *	Writes back to memory all dirty cache entries
 *	that cache data from the specified memory range,
 *	and marks these entries as clean.
 *	NOTE: on some future implementations, this might
 *		also invalidate.
 *	NOTE: locked entries are written back, but never invalidated.
 *	NOTE: instruction caches never implement writeback.
 *
 *  writeback_inv_line		(single cache line)
 *  writeback_inv_region	(specified memory range)
 *  writeback_inv_all		(entire cache)
 *	Writes back to memory all dirty cache entries
 *	that cache data from the specified memory range,
 *	and invalidates these entries (including all clean
 *	cache entries that cache data from that range).
 *	NOTE: locked entries are written back but not invalidated.
 *	NOTE: instruction caches never implement writeback.
 *
 *  lock_line			(single cache line)
 *  lock_region			(specified memory range)
 *	Prefetch and lock the specified memory range into cache.
 *	NOTE:  if any part of the specified memory range cannot
 *	be locked, a ??? exception occurs.  These macros don't
 *	do anything special (yet anyway) to handle this situation.
 *
 *  unlock_line			(single cache line)
 *  unlock_region		(specified memory range)
 *  unlock_all			(entire cache)
 *	Unlock cache entries that cache the specified memory range.
 *	Entries not already locked are unaffected.
 */



/***************************   GENERIC -- ALL CACHES   ***************************/


/*
 *  The following macros assume the following cache size/parameter limits
 *  in the current Xtensa core implementation:
 *	cache size:	1024 bytes minimum
 *	line size:	16 - 64 bytes
 *	way count:	1 - 4
 *
 *  Minimum entries per way (ie. per associativity) = 1024 / 64 / 4 = 4
 *  Hence the assumption that each loop can execute four cache instructions.
 *
 *  Correspondingly, the offset range of instructions is assumed able to cover
 *  four lines, ie. offsets {0,1,2,3} * line_size are assumed valid for
 *  both hit and indexed cache instructions.  Ie. these offsets are all
 *  valid:  0, 16, 32, 48, 64, 96, 128, 192 (for line sizes 16, 32, 64).
 *  This is true of all original cache instructions
 *  (dhi, ihi, dhwb, dhwbi, dii, iii) which have offsets
 *  of 0 to 1020 in multiples of 4 (ie. 8 bits shifted by 2).
 *  This is also true of subsequent cache instructions
 *  (dhu, ihu, diu, iiu, diwb, diwbi, dpfl, ipfl) which have offsets
 *  of 0 to 240 in multiples of 16 (ie. 4 bits shifted by 4).
 *
 *  (Maximum cache size, currently 32k, doesn't affect the following macros.
 *  Cache ways > MMU min page size cause aliasing but that's another matter.)
 */



/*
 *  Macro to apply an 'indexed' cache instruction to the entire cache.
 *
 *  Parameters:
 *	cainst		instruction/ that takes an address register parameter
 *			and an offset parameter (in range 0 .. 3*linesize).
 *	size		size of cache in bytes
 *	linesize	size of cache line in bytes
 *	assoc_or1	number of associativities (ways/sets) in cache
 *			if all sets affected by cainst,
 *			or 1 if only one set (or not all sets) of the cache
 *			is affected by cainst (eg. DIWB or DIWBI [not yet ISA defined]).
 *	aa, ab		unique address registers (temporaries)
 */

	.macro	cache_index_all		cainst, size, linesize, assoc_or1, aa, ab

	//  Sanity-check on cache parameters:
	.ifne	(\size % (\linesize * \assoc_or1 * 4))
	.err	//  cache configuration outside expected/supported range!
	.endif

	//  \size byte cache, \linesize byte lines, \assoc_or1 way(s) affected by each \cainst.
	movi	\aa, (\size / (\linesize * \assoc_or1 * 4))
	// Possible improvement: need only loop if \aa > 1 ;
	// however that particular condition is highly unlikely.
	movi	\ab, 0		// to iterate over cache
	floop		\aa, cachex\@
	\cainst		\ab, 0*\linesize
	\cainst		\ab, 1*\linesize
	\cainst		\ab, 2*\linesize
	\cainst		\ab, 3*\linesize
	addi		\ab, \ab, 4*\linesize	// move to next line
	floopend	\aa, cachex\@

	.endm


/*
 *  Macro to apply a 'hit' cache instruction to a memory region,
 *  ie. to any cache entries that cache a specified portion (region) of memory.
 *  Takes care of the unaligned cases, ie. may apply to one
 *  more cache line than $asize / lineSize if $aaddr is not aligned.
 *
 *
 *  Parameters are:
 *	cainst	instruction/macro that takes an address register parameter
 *		and an offset parameter (currently always zero)
 *		and generates a cache instruction (eg. "dhi", "dhwb", "ihi", etc.)
 *	linesize_log2	log2(size of cache line in bytes)
 *	addr	register containing start address of region (clobbered)
 *	asize	register containing size of the region in bytes (clobbered)
 *	askew	unique register used as temporary
 *
 * !?!?! 2DO: optimization: iterate max(cache_size and \asize) / linesize
 */

	.macro	cache_hit_region	cainst, linesize_log2, addr, asize, askew

	//  Make \asize the number of iterations:
	extui	\askew, \addr, 0, \linesize_log2	// get unalignment amount of \addr
	add	\asize, \asize, \askew			// ... and add it to \asize
	addi	\asize, \asize, (1 << \linesize_log2) - 1	// round up!
	srli	\asize, \asize, \linesize_log2

	//  Iterate over region:
	floopnez	\asize, cacheh\@
	\cainst		\addr, 0
	addi		\addr, \addr, (1 << \linesize_log2)	// move to next line
	floopend	\asize, cacheh\@

	.endm





/***************************   INSTRUCTION CACHE   ***************************/


/*
 *  Reset/initialize the instruction cache by simply invalidating it:
 *  (need to unlock first also, if cache locking implemented):
 *
 *  Parameters:
 *	aa, ab		unique address registers (temporaries)
 */
	.macro	icache_reset	aa, ab
	icache_unlock_all	\aa, \ab
	icache_invalidate_all	\aa, \ab
	.endm


/*
 * Synchronize after an instruction cache operation,
 * to be sure everything is in sync with memory as to be
 * expected following any previous instruction cache control operations.
 *
 * Parameters are:
 *	ar	an address register (temporary) (currently unused, but may be used in future)
 */
	.macro	icache_sync	ar
#if XCHAL_ICACHE_SIZE > 0
	isync
#endif
	.endm



/*
 *  Invalidate a single line of the instruction cache.
 *  Parameters are:
 *	ar	address register that contains (virtual) address to invalidate
 *		(may get clobbered in a future implementation, but not currently)
 *	offset	(optional) offset to add to \ar to compute effective address to invalidate
 *		(note: some number of lsbits are ignored)
 */
	.macro	icache_invalidate_line	ar, offset
#if XCHAL_ICACHE_SIZE > 0
	ihi	\ar, \offset		// invalidate icache line
	/*
	 *  NOTE:  in some version of the silicon [!!!SHOULD HAVE BEEN DOCUMENTED!!!]
	 *  'ihi' doesn't work, so it had been replaced with 'iii'
	 *  (which would just invalidate more than it should,
	 *  which should be okay other than the performance hit
	 *  because cache locking did not exist in that version,
	 *  unless user somehow relies on something being cached).
	 *  [WHAT VERSION IS IT!!?!?
	 *  IS THERE ANY WAY TO TEST FOR THAT HERE, TO OUTPUT 'III' ONLY IF NEEDED!?!?].
	 *
	 *	iii	\ar, \offset
	 */
	icache_sync	\ar
#endif
	.endm




/*
 *  Invalidate instruction  cache entries that cache a specified portion of memory.
 *  Parameters are:
 *	astart	start address (register gets clobbered)
 *	asize	size of the region in bytes (register gets clobbered)
 *	ac	unique register used as temporary
 */
	.macro	icache_invalidate_region	astart, asize, ac
#if XCHAL_ICACHE_SIZE > 0
	//  Instruction cache region invalidation:
	cache_hit_region	ihi, XCHAL_ICACHE_LINEWIDTH, \astart, \asize, \ac
	icache_sync	\ac
	//  End of instruction cache region invalidation
#endif
	.endm



/*
 *  Invalidate entire instruction cache.
 *
 *  Parameters:
 *	aa, ab		unique address registers (temporaries)
 */
	.macro	icache_invalidate_all	aa, ab
#if XCHAL_ICACHE_SIZE > 0
	//  Instruction cache invalidation:
	cache_index_all		iii, XCHAL_ICACHE_SIZE, XCHAL_ICACHE_LINESIZE, XCHAL_ICACHE_WAYS, \aa, \ab
	icache_sync	\aa
	//  End of instruction cache invalidation
#endif
	.endm



/*
 *  Lock (prefetch & lock) a single line of the instruction cache.
 *
 *  Parameters are:
 *	ar	address register that contains (virtual) address to lock
 *		(may get clobbered in a future implementation, but not currently)
 *	offset	offset to add to \ar to compute effective address to lock
 *		(note: some number of lsbits are ignored)
 */
	.macro	icache_lock_line	ar, offset
#if XCHAL_ICACHE_SIZE > 0 && XCHAL_ICACHE_LINE_LOCKABLE
	ipfl	\ar, \offset	/* prefetch and lock icache line */
	icache_sync	\ar
#endif
	.endm



/*
 *  Lock (prefetch & lock) a specified portion of memory into the instruction cache.
 *  Parameters are:
 *	astart	start address (register gets clobbered)
 *	asize	size of the region in bytes (register gets clobbered)
 *	ac	unique register used as temporary
 */
	.macro	icache_lock_region	astart, asize, ac
#if XCHAL_ICACHE_SIZE > 0 && XCHAL_ICACHE_LINE_LOCKABLE
	//  Instruction cache region lock:
	cache_hit_region	ipfl, XCHAL_ICACHE_LINEWIDTH, \astart, \asize, \ac
	icache_sync	\ac
	//  End of instruction cache region lock
#endif
	.endm



/*
 *  Unlock a single line of the instruction cache.
 *
 *  Parameters are:
 *	ar	address register that contains (virtual) address to unlock
 *		(may get clobbered in a future implementation, but not currently)
 *	offset	offset to add to \ar to compute effective address to unlock
 *		(note: some number of lsbits are ignored)
 */
	.macro	icache_unlock_line	ar, offset
#if XCHAL_ICACHE_SIZE > 0 && XCHAL_ICACHE_LINE_LOCKABLE
	ihu	\ar, \offset	/* unlock icache line */
	icache_sync	\ar
#endif
	.endm



/*
 *  Unlock a specified portion of memory from the instruction cache.
 *  Parameters are:
 *	astart	start address (register gets clobbered)
 *	asize	size of the region in bytes (register gets clobbered)
 *	ac	unique register used as temporary
 */
	.macro	icache_unlock_region	astart, asize, ac
#if XCHAL_ICACHE_SIZE > 0 && XCHAL_ICACHE_LINE_LOCKABLE
	//  Instruction cache region unlock:
	cache_hit_region	ihu, XCHAL_ICACHE_LINEWIDTH, \astart, \asize, \ac
	icache_sync	\ac
	//  End of instruction cache region unlock
#endif