1 /*
2  * Contains routines needed to support swiotlb for ppc.
3  *
4  * Copyright (C) 2009 Becky Bruce, Freescale Semiconductor
5  *
6  * This program is free software; you can redistribute  it and/or modify it
7  * under  the terms of  the GNU General  Public License as published by the
8  * Free Software Foundation;  either version 2 of the  License, or (at your
9  * option) any later version.
10  *
11  */
12 
13 #include <linux/dma-mapping.h>
14 #include <linux/pfn.h>
15 #include <linux/of_platform.h>
16 #include <linux/platform_device.h>
17 #include <linux/pci.h>
18 
19 #include <asm/machdep.h>
20 #include <asm/swiotlb.h>
21 #include <asm/dma.h>
22 #include <asm/abs_addr.h>
23 
24 unsigned int ppc_swiotlb_enable;
25 
26 /*
27  * At the moment, all platforms that use this code only require
28  * swiotlb to be used if we're operating on HIGHMEM.  Since
29  * we don't ever call anything other than map_sg, unmap_sg,
30  * map_page, and unmap_page on highmem, use normal dma_ops
31  * for everything else.
32  */
33 struct dma_map_ops swiotlb_dma_ops = {
34 	.alloc_coherent = dma_direct_alloc_coherent,
35 	.free_coherent = dma_direct_free_coherent,
36 	.map_sg = swiotlb_map_sg_attrs,
37 	.unmap_sg = swiotlb_unmap_sg_attrs,
38 	.dma_supported = swiotlb_dma_supported,
39 	.map_page = swiotlb_map_page,
40 	.unmap_page = swiotlb_unmap_page,
41 	.sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
42 	.sync_single_range_for_device = swiotlb_sync_single_range_for_device,
43 	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
44 	.sync_sg_for_device = swiotlb_sync_sg_for_device,
45 	.mapping_error = swiotlb_dma_mapping_error,
46 };
47 
48 void pci_dma_dev_setup_swiotlb(struct pci_dev *pdev)
49 {
50 	struct pci_controller *hose;
51 	struct dev_archdata *sd;
52 
53 	hose = pci_bus_to_host(pdev->bus);
54 	sd = &pdev->dev.archdata;
55 	sd->max_direct_dma_addr =
56 		hose->dma_window_base_cur + hose->dma_window_size;
57 }
58 
59 static int ppc_swiotlb_bus_notify(struct notifier_block *nb,
60 				  unsigned long action, void *data)
61 {
62 	struct device *dev = data;
63 	struct dev_archdata *sd;
64 
65 	/* We are only intereted in device addition */
66 	if (action != BUS_NOTIFY_ADD_DEVICE)
67 		return 0;
68 
69 	sd = &dev->archdata;
70 	sd->max_direct_dma_addr = 0;
71 
72 	/* May need to bounce if the device can't address all of DRAM */
73 	if (dma_get_mask(dev) < lmb_end_of_DRAM())
74 		set_dma_ops(dev, &swiotlb_dma_ops);
75 
76 	return NOTIFY_DONE;
77 }
78 
79 static struct notifier_block ppc_swiotlb_plat_bus_notifier = {
80 	.notifier_call = ppc_swiotlb_bus_notify,
81 	.priority = 0,
82 };
83 
84 static struct notifier_block ppc_swiotlb_of_bus_notifier = {
85 	.notifier_call = ppc_swiotlb_bus_notify,
86 	.priority = 0,
87 };
88 
89 int __init swiotlb_setup_bus_notifier(void)
90 {
91 	bus_register_notifier(&platform_bus_type,
92 			      &ppc_swiotlb_plat_bus_notifier);
93 	bus_register_notifier(&of_platform_bus_type,
94 			      &ppc_swiotlb_of_bus_notifier);
95 
96 	return 0;
97 }
98