arch/powerpc/platforms/celleb/iommu.c

   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 void __init celleb_init_direct_mapping(void)
  56 {
  57         u64 lpar_addr, io_addr;
  58         u64 io_space_id, ioid, dma_base, dma_size, io_page_size;
  59
  60         if (!find_dma_window(&io_space_id, &ioid, &dma_base, &dma_size,
  61                              &io_page_size)) {
  62                 pr_info("No dma window found !\n");
  63                 return;
  64         }
  65
  66         for (lpar_addr = 0; lpar_addr < dma_size; lpar_addr += io_page_size) {
  67                 io_addr = lpar_addr + dma_base;
  68                 (void)beat_put_iopte(io_space_id, io_addr, lpar_addr,
  69                                      ioid, DMA_FLAGS);
  70         }
  71
  72         dma_direct_offset = dma_base;
  73 }
  74
  75 static int celleb_of_bus_notify(struct notifier_block *nb,
  76                                 unsigned long action, void *data)
  77 {
  78         struct device *dev = data;
  79
  80         /* We are only intereted in device addition */
  81         if (action != BUS_NOTIFY_ADD_DEVICE)
  82                 return 0;
  83
  84         dev->archdata.dma_ops = get_pci_dma_ops();
  85
  86         return 0;
  87 }
  88
  89 static struct notifier_block celleb_of_bus_notifier = {
  90         .notifier_call = celleb_of_bus_notify
  91 };
  92
  93 static int __init celleb_init_iommu(void)
  94 {
  95         if (!machine_is(celleb_beat))
  96                 return -ENODEV;
  97
  98         celleb_init_direct_mapping();
  99         set_pci_dma_ops(&dma_direct_ops);
 100         bus_register_notifier(&of_platform_bus_type, &celleb_of_bus_notifier);
 101
 102         return 0;
 103 }
 104
 105 arch_initcall(celleb_init_iommu);