wut/include/coreinit/cache.h
James Benton 7492ff0483 Fix formatting.
Maybe we should start using clang-format for wut.
2020-05-07 15:29:59 +01:00

203 lines
6.2 KiB
C

#pragma once
#include <wut.h>
/**
* \defgroup coreinit_cache Cache
* \ingroup coreinit
*
* Interface to the low-level caching system of the PowerPC processor.
*
* The cache acts as a middleman between main
* memory and the processor, speeding up access to frequently-used data.
* However, the Wii U is not cache-coherent - written data may be cached
* without updating main memory, and data read from the cache may be out of date
* with respect to memory. While this isn't a problem for most code, certain
* hardware accesses may require manual synchronisation of the cache. This is
* achieved with coreinit's Cache group of functions.
*
* Since the PowerPC has a seperate cache for data and instructions, any data
* written with the intent of executing it as instructions requires manual
* flushing and invalidation of the data and instruction caches.
* @{
*/
#ifdef __cplusplus
extern "C" {
#endif
/**
* Invalidates a range of cached data, in blocks. Equivalent to a loop of
* PowerPC \c dcbi instructions.
*
* This function forces the next reads from the given address to bypass the
* the cache and go straight to memory, resulting in slower reads that are
* guaranteed to reflect main memory.
*
* \param addr
* The effective address of the data to invalidate.
*
* \param size
* The size of the range to invalidate. Will be rounded up to the next 0x20.
*
* \note
* Unnecessary use of caching functions can have an adverse performance impact.
* They should only be used when needed while interfacing with hardware.
*/
void
DCInvalidateRange(void *addr,
uint32_t size);
/**
* Flushes a range of cached data, in blocks. Equivalent to a loop of PowerPC
* \c dcbf instructions, followed by a \c sync and \c eieio.
*
* This function flushes any recently cached data into main memory.
* This allows other hardware in the console to read the data without worry
* of main memory being outdated. It will also invalidate cached data.
*
* \param addr
* The effective address of the data to flush.
*
* \param size
* The size of the range to flush. Will be rounded up to the next 0x20.
*
* \note
* Unnecessary use of caching functions can have an adverse performance impact.
* They should only be used when needed while interfacing with hardware.
*/
void
DCFlushRange(void *addr,
uint32_t size);
/**
* Stores a range of cached data, in blocks. Equivalent to a loop of PowerPC
* \c dcbst instructions, followed by a \c sync and \c eieio.
*
* This function writes any recently cached data into main memory.
* This allows other hardware in the console to read the data without worry
* of main memory being outdated. This function does <em>not</em> invalidate
* the cached data.
*
* \param addr
* The effective address of the data to store.
*
* \param size
* The size of the range to store. Will be rounded up to the next 0x20.
*
* \note
* Unnecessary use of caching functions can have an adverse performance impact.
* They should only be used when needed while interfacing with hardware.
*/
void
DCStoreRange(void *addr,
uint32_t size);
/**
* Similar to \link DCFlushRange \endlink, though this function will
* <em>not</em> run PowerPC \c sync and \c eieio instructions after flushing.
*
* \param addr
* The effective address of the data to flush.
*
* \param size
* The size of the range to flush. Will be rounded up to the next 0x20.
*
* \note
* Unnecessary use of caching functions can have an adverse performance impact.
* They should only be used when needed while interfacing with hardware.
*/
void
DCFlushRangeNoSync(void *addr,
uint32_t size);
/**
* Similar to \link DCStoreRange \endlink, though this function will
* <em>not</em> run PowerPC \c sync and \c eieio instructions after storing.
*
* \param addr
* The effective address of the data to store.
*
* \param size
* The size of the range to store. Will be rounded up to the next 0x20.
*
* \note
* Unnecessary use of caching functions can have an adverse performance impact.
* They should only be used when needed while interfacing with hardware.
*/
void
DCStoreRangeNoSync(void *addr,
uint32_t size);
/**
* Zeroes the given area of the data cache (to the nearest block) with a loop of
* PowerPC \c dcbz instructions.
* This will not affect main memory immediately, though it will eventually
* trickle down. Can be combined with \link DCFlushRange \endlink or
* \link DCStoreRange \endlink to efficiently set memory to 0.
*
* \warning
* The size of the range passed into this function will be internally rounded up
* to the next multiple of 0x20. Failing to account for this could result in
* delayed, hard-to-diagnose memory corruption.
*
* \param addr
* The effective address of the data to zero.
*
* \param size
* The size of the range to zero. Will be rounded up to the next 0x20.
*/
void
DCZeroRange(void *addr,
uint32_t size);
/**
* Gives the processor a hint that the given range of memory is likely to be
* accessed soon, and that performance would be improved if it were cached.
* The processor does not have to cache the requested area, but it may do so in
* response to this function. This function is equvalent to a loop of PowerPC
* \c dcbt instructions.
*
* \param addr
* The effective address of the data to cache.
*
* \param size
* The size of the range to cache. Will be rounded up to the next 0x20.
*/
void
DCTouchRange(void *addr,
uint32_t size);
/**
* Invalidates a range of cached instructions, in blocks. Equivalent to a loop
* of PowerPC \c icbi instructions.
*
* This function forces the next instruction fetches from the given address to
* bypass the the cache and go straight to memory, resulting in slower fetches
* that are guaranteed to reflect main memory.
*
* \param addr
* The effective address of the instructions to invalidate.
*
* \param size
* The size of the range to invalidate. Will be rounded up to the next 0x20.
*
* \note
* Unnecessary use of caching functions can have an adverse performance impact.
* They should only be used when needed while interfacing with hardware.
*/
void
ICInvalidateRange(void *addr,
uint32_t size);
void
OSMemoryBarrier();
#ifdef __cplusplus
}
#endif
/** @} */