cacheCoherentMemoryProvider.cpp File Reference

Provides a way to easily allocate memory areas that are coherent between CPU and DMA. More...

#include <stdint.h>
#include <stdlib.h>
#include "../notMine/mailbox.h"
#include <CCRCodingUtils/include/errorManagement.h>
#include <memoryManagement/physMemoryManagement.h>
#include <memoryManagement/addressing.h>
#include <memoryManagement/cacheCoherentMemoryProvider.h>

Functions
int	ccmp_malloc (size_t reqSize, Ccmb_desc *allocatedAreaDesc, unsigned int byteAlignment)
	Provides a way to easily allocate memory areas that are coherent between CPU and DMA. More...
int	ccmp_free (Ccmb_desc *allocatedAreaDesc)
	Frees a block allocated with ccmp_malloc() More...
uintptr_t	ccmp_virtAddrToBusAddr (Ccmb_desc *desc, void *virtAddr)
	Converts a virtual address inside the block described by desc to it's bus address. More...

Detailed Description

Provides a way to easily allocate memory areas that are coherent between CPU and DMA.

See cacheCoherentMemoryProvider.h

This file uses the "mailbox property interface". I didn't find a complete and clear documentation but only vague and sparse informations. So I'll use the files mailbox.c and mailbox.h taken from https://github.com/raspberrypi/userland/blob/master/host_applications/linux/apps/hello_pi/hello_fft/ And some information taken from the sources of servoblaster and piblaster. Thanks to servoblaster, piblaster, the raspberry foundation and broadcom.

Function Documentation

int ccmp_free

(

Ccmb_desc *

allocatedAreaDesc

)

Frees a block allocated with ccmp_malloc()

Returns

negative in case of error

int ccmp_malloc	(	size_t	reqSize,
		Ccmb_desc *	allocatedAreaDesc,
		unsigned int	byteAlignment
	)

Provides a way to easily allocate memory areas that are coherent between CPU and DMA.

Parameters

reqSize	The size of the block to be allocated.
allocatedAreaDesc	Here will be returned the descriptor for the allocated block
byteAlignment	The allocated block will be aligned to this value

Returns

negative in case of error

uintptr_t ccmp_virtAddrToBusAddr	(	Ccmb_desc *	desc,
		void *	virtAddr
	)

Converts a virtual address inside the block described by desc to it's bus address.

Returns

the bus address