linuxdebug/include/linux/soc/apple/sart.h

54 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only OR MIT */
/*
* Apple SART device driver
* Copyright (C) The Asahi Linux Contributors
*
* Apple SART is a simple address filter for DMA transactions.
* Regions of physical memory must be added to the SART's allow
* list before any DMA can target these. Unlike a proper
* IOMMU no remapping can be done.
*/
#ifndef _LINUX_SOC_APPLE_SART_H_
#define _LINUX_SOC_APPLE_SART_H_
#include <linux/device.h>
#include <linux/err.h>
#include <linux/types.h>
struct apple_sart;
/*
* Get a reference to the SART attached to dev.
*
* Looks for the phandle reference in apple,sart and returns a pointer
* to the corresponding apple_sart struct to be used with
* apple_sart_add_allowed_region and apple_sart_remove_allowed_region.
*/
struct apple_sart *devm_apple_sart_get(struct device *dev);
/*
* Adds the region [paddr, paddr+size] to the DMA allow list.
*
* @sart: SART reference
* @paddr: Start address of the region to be used for DMA
* @size: Size of the region to be used for DMA.
*/
int apple_sart_add_allowed_region(struct apple_sart *sart, phys_addr_t paddr,
size_t size);
/*
* Removes the region [paddr, paddr+size] from the DMA allow list.
*
* Note that exact same paddr and size used for apple_sart_add_allowed_region
* have to be passed.
*
* @sart: SART reference
* @paddr: Start address of the region no longer used for DMA
* @size: Size of the region no longer used for DMA.
*/
int apple_sart_remove_allowed_region(struct apple_sart *sart, phys_addr_t paddr,
size_t size);
#endif /* _LINUX_SOC_APPLE_SART_H_ */