Linux Kernel  3.7.1
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beat_iommu.c
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1 /*
2  * Support for IOMMU on Celleb platform.
3  *
4  * (C) Copyright 2006-2007 TOSHIBA CORPORATION
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License along
17  * with this program; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19  */
20 
21 #include <linux/kernel.h>
22 #include <linux/init.h>
23 #include <linux/dma-mapping.h>
24 #include <linux/pci.h>
25 #include <linux/of_platform.h>
26 
27 #include <asm/machdep.h>
28 
29 #include "beat_wrapper.h"
30 
31 #define DMA_FLAGS 0xf800000000000000UL /* r/w permitted, coherency required,
32  strongest order */
33 
34 static int __init find_dma_window(u64 *io_space_id, u64 *ioid,
35  u64 *base, u64 *size, u64 *io_page_size)
36 {
37  struct device_node *dn;
38  const unsigned long *dma_window;
39 
40  for_each_node_by_type(dn, "ioif") {
41  dma_window = of_get_property(dn, "toshiba,dma-window", NULL);
42  if (dma_window) {
43  *io_space_id = (dma_window[0] >> 32) & 0xffffffffUL;
44  *ioid = dma_window[0] & 0x7ffUL;
45  *base = dma_window[1];
46  *size = dma_window[2];
47  *io_page_size = 1 << dma_window[3];
48  of_node_put(dn);
49  return 1;
50  }
51  }
52  return 0;
53 }
54 
55 static unsigned long celleb_dma_direct_offset;
56 
57 static void __init celleb_init_direct_mapping(void)
58 {
59  u64 lpar_addr, io_addr;
60  u64 io_space_id, ioid, dma_base, dma_size, io_page_size;
61 
62  if (!find_dma_window(&io_space_id, &ioid, &dma_base, &dma_size,
63  &io_page_size)) {
64  pr_info("No dma window found !\n");
65  return;
66  }
67 
68  for (lpar_addr = 0; lpar_addr < dma_size; lpar_addr += io_page_size) {
69  io_addr = lpar_addr + dma_base;
70  (void)beat_put_iopte(io_space_id, io_addr, lpar_addr,
71  ioid, DMA_FLAGS);
72  }
73 
74  celleb_dma_direct_offset = dma_base;
75 }
76 
77 static void celleb_dma_dev_setup(struct device *dev)
78 {
79  set_dma_ops(dev, &dma_direct_ops);
80  set_dma_offset(dev, celleb_dma_direct_offset);
81 }
82 
83 static void celleb_pci_dma_dev_setup(struct pci_dev *pdev)
84 {
85  celleb_dma_dev_setup(&pdev->dev);
86 }
87 
88 static int celleb_of_bus_notify(struct notifier_block *nb,
89  unsigned long action, void *data)
90 {
91  struct device *dev = data;
92 
93  /* We are only intereted in device addition */
94  if (action != BUS_NOTIFY_ADD_DEVICE)
95  return 0;
96 
97  celleb_dma_dev_setup(dev);
98 
99  return 0;
100 }
101 
102 static struct notifier_block celleb_of_bus_notifier = {
103  .notifier_call = celleb_of_bus_notify
104 };
105 
106 static int __init celleb_init_iommu(void)
107 {
108  celleb_init_direct_mapping();
109  ppc_md.pci_dma_dev_setup = celleb_pci_dma_dev_setup;
110  bus_register_notifier(&platform_bus_type, &celleb_of_bus_notifier);
111 
112  return 0;
113 }
114 
115 machine_arch_initcall(celleb_beat, celleb_init_iommu);