1 /*
2 * Contains routines needed to support swiotlb for ppc.
3 *
4 * Copyright (C) 2009-2010 Freescale Semiconductor, Inc.
5 * Author: Becky Bruce
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
11 *
12 */
13
14 #include <linux/dma-mapping.h>
15 #include <linux/memblock.h>
16 #include <linux/pfn.h>
17 #include <linux/of_platform.h>
18 #include <linux/platform_device.h>
19 #include <linux/pci.h>
20
21 #include <asm/machdep.h>
22 #include <asm/swiotlb.h>
23 #include <asm/dma.h>
24
25 unsigned int ppc_swiotlb_enable;
26
swiotlb_powerpc_get_required(struct device * dev)27 static u64 swiotlb_powerpc_get_required(struct device *dev)
28 {
29 u64 end, mask, max_direct_dma_addr = dev->archdata.max_direct_dma_addr;
30
31 end = memblock_end_of_DRAM();
32 if (max_direct_dma_addr && end > max_direct_dma_addr)
33 end = max_direct_dma_addr;
34 end += get_dma_offset(dev);
35
36 mask = 1ULL << (fls64(end) - 1);
37 mask += mask - 1;
38
39 return mask;
40 }
41
42 /*
43 * At the moment, all platforms that use this code only require
44 * swiotlb to be used if we're operating on HIGHMEM. Since
45 * we don't ever call anything other than map_sg, unmap_sg,
46 * map_page, and unmap_page on highmem, use normal dma_ops
47 * for everything else.
48 */
49 struct dma_map_ops swiotlb_dma_ops = {
50 .alloc = __dma_direct_alloc_coherent,
51 .free = __dma_direct_free_coherent,
52 .mmap = dma_direct_mmap_coherent,
53 .map_sg = swiotlb_map_sg_attrs,
54 .unmap_sg = swiotlb_unmap_sg_attrs,
55 .dma_supported = swiotlb_dma_supported,
56 .map_page = swiotlb_map_page,
57 .unmap_page = swiotlb_unmap_page,
58 .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
59 .sync_single_for_device = swiotlb_sync_single_for_device,
60 .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
61 .sync_sg_for_device = swiotlb_sync_sg_for_device,
62 .mapping_error = swiotlb_dma_mapping_error,
63 .get_required_mask = swiotlb_powerpc_get_required,
64 };
65
pci_dma_dev_setup_swiotlb(struct pci_dev * pdev)66 void pci_dma_dev_setup_swiotlb(struct pci_dev *pdev)
67 {
68 struct pci_controller *hose;
69 struct dev_archdata *sd;
70
71 hose = pci_bus_to_host(pdev->bus);
72 sd = &pdev->dev.archdata;
73 sd->max_direct_dma_addr =
74 hose->dma_window_base_cur + hose->dma_window_size;
75 }
76
ppc_swiotlb_bus_notify(struct notifier_block * nb,unsigned long action,void * data)77 static int ppc_swiotlb_bus_notify(struct notifier_block *nb,
78 unsigned long action, void *data)
79 {
80 struct device *dev = data;
81 struct dev_archdata *sd;
82
83 /* We are only intereted in device addition */
84 if (action != BUS_NOTIFY_ADD_DEVICE)
85 return 0;
86
87 sd = &dev->archdata;
88 sd->max_direct_dma_addr = 0;
89
90 /* May need to bounce if the device can't address all of DRAM */
91 if ((dma_get_mask(dev) + 1) < memblock_end_of_DRAM())
92 set_dma_ops(dev, &swiotlb_dma_ops);
93
94 return NOTIFY_DONE;
95 }
96
97 static struct notifier_block ppc_swiotlb_plat_bus_notifier = {
98 .notifier_call = ppc_swiotlb_bus_notify,
99 .priority = 0,
100 };
101
swiotlb_setup_bus_notifier(void)102 int __init swiotlb_setup_bus_notifier(void)
103 {
104 bus_register_notifier(&platform_bus_type,
105 &ppc_swiotlb_plat_bus_notifier);
106 return 0;
107 }
108
swiotlb_detect_4g(void)109 void __init swiotlb_detect_4g(void)
110 {
111 if ((memblock_end_of_DRAM() - 1) > 0xffffffff) {
112 ppc_swiotlb_enable = 1;
113 #ifdef CONFIG_ZONE_DMA32
114 limit_zone_pfn(ZONE_DMA32, (1ULL << 32) >> PAGE_SHIFT);
115 #endif
116 }
117 }
118
check_swiotlb_enabled(void)119 static int __init check_swiotlb_enabled(void)
120 {
121 if (ppc_swiotlb_enable)
122 swiotlb_print_info();
123 else
124 swiotlb_free();
125
126 return 0;
127 }
128 subsys_initcall(check_swiotlb_enabled);
129