1 | /* SPDX-License-Identifier: GPL-2.0-only OR MIT */ |
2 | /* |
3 | * Apple SART device driver |
4 | * Copyright (C) The Asahi Linux Contributors |
5 | * |
6 | * Apple SART is a simple address filter for DMA transactions. |
7 | * Regions of physical memory must be added to the SART's allow |
8 | * list before any DMA can target these. Unlike a proper |
9 | * IOMMU no remapping can be done. |
10 | */ |
11 | |
12 | #ifndef _LINUX_SOC_APPLE_SART_H_ |
13 | #define _LINUX_SOC_APPLE_SART_H_ |
14 | |
15 | #include <linux/device.h> |
16 | #include <linux/err.h> |
17 | #include <linux/types.h> |
18 | |
19 | struct apple_sart; |
20 | |
21 | /* |
22 | * Get a reference to the SART attached to dev. |
23 | * |
24 | * Looks for the phandle reference in apple,sart and returns a pointer |
25 | * to the corresponding apple_sart struct to be used with |
26 | * apple_sart_add_allowed_region and apple_sart_remove_allowed_region. |
27 | */ |
28 | struct apple_sart *devm_apple_sart_get(struct device *dev); |
29 | |
30 | /* |
31 | * Adds the region [paddr, paddr+size] to the DMA allow list. |
32 | * |
33 | * @sart: SART reference |
34 | * @paddr: Start address of the region to be used for DMA |
35 | * @size: Size of the region to be used for DMA. |
36 | */ |
37 | int apple_sart_add_allowed_region(struct apple_sart *sart, phys_addr_t paddr, |
38 | size_t size); |
39 | |
40 | /* |
41 | * Removes the region [paddr, paddr+size] from the DMA allow list. |
42 | * |
43 | * Note that exact same paddr and size used for apple_sart_add_allowed_region |
44 | * have to be passed. |
45 | * |
46 | * @sart: SART reference |
47 | * @paddr: Start address of the region no longer used for DMA |
48 | * @size: Size of the region no longer used for DMA. |
49 | */ |
50 | int apple_sart_remove_allowed_region(struct apple_sart *sart, phys_addr_t paddr, |
51 | size_t size); |
52 | |
53 | #endif /* _LINUX_SOC_APPLE_SART_H_ */ |
54 | |