u-boot/include/smem.h
Ramon Fried 7b384eccc7 dm: SMEM (Shared memory) uclass
This is a uclass for Shared memory manager drivers.

A Shared Memory Manager driver implements an interface for allocating
and accessing items in the memory area shared among all of the
processors.

Signed-off-by: Ramon Fried <ramon.fried@gmail.com>

Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
2018-07-19 16:31:37 -04:00

91 lines
2.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* The shared memory system is an allocate-only heap structure that
* consists of one of more memory areas that can be accessed by the processors
* in the SoC.
*
* Allocation can be done globally for all processors or to an individual processor.
* This is controlled by the @host parameter.
*
* Allocation and management of heap can be implemented in various ways,
* The @item parameter should be used as an index/hash to the memory region.
*
* Copyright (c) 2018 Ramon Fried <ramon.fried@gmail.com>
*/
#ifndef _smemh_
#define _smemh_
/* struct smem_ops: Operations for the SMEM uclass */
struct smem_ops {
/**
* alloc() - allocate space for a smem item
*
* @host: remote processor id, or -1 for all processors.
* @item: smem item handle
* @size: number of bytes to be allocated
* @return 0 if OK, -ve on error
*/
int (*alloc)(unsigned int host,
unsigned int item, size_t size);
/**
* get() - Resolve ptr of size of a smem item
*
* @host: the remote processor, of -1 for all processors.
* @item: smem item handle
* @size: pointer to be filled out with the size of the item
* @return pointer on success, NULL on error
*/
void *(*get)(unsigned int host,
unsigned int item, size_t *size);
/**
* get_free_space() - Get free space in smem in bytes
*
* @host: the remote processor identifying a partition, or -1
* for all processors.
* @return free space, -ve on error
*/
int (*get_free_space)(unsigned int host);
};
#define smem_get_ops(dev) ((struct smem_ops *)(dev)->driver->ops)
/**
* smem_alloc() - allocate space for a smem item
* @host: remote processor id, or -1
* @item: smem item handle
* @size: number of bytes to be allocated
* @return 0 if OK, -ve on error
*
* Allocate space for a given smem item of size @size, given that the item is
* not yet allocated.
*/
int smem_alloc(struct udevice *dev, unsigned int host, unsigned int item, size_t size);
/**
* smem_get() - resolve ptr of size of a smem item
* @host: the remote processor, or -1 for all processors.
* @item: smem item handle
* @size: pointer to be filled out with size of the item
* @return pointer on success, NULL on error
*
* Looks up smem item and returns pointer to it. Size of smem
* item is returned in @size.
*/
void *smem_get(struct udevice *dev, unsigned int host, unsigned int item, size_t *size);
/**
* smem_get_free_space() - retrieve amount of free space in a partition
* @host: the remote processor identifying a partition, or -1
* for all processors.
* @return size in bytes, -ve on error
*
* To be used by smem clients as a quick way to determine if any new
* allocations has been made.
*/
int smem_get_free_space(struct udevice *dev, unsigned int host);
#endif /* _smem_h_ */