arch/powerpc/kernel/dma-swiotlb.c

   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 int swiotlb __read_mostly;
  25 unsigned int ppc_swiotlb_enable;
  26
  27 /*
  28  * At the moment, all platforms that use this code only require
  29  * swiotlb to be used if we're operating on HIGHMEM.  Since
  30  * we don't ever call anything other than map_sg, unmap_sg,
  31  * map_page, and unmap_page on highmem, use normal dma_ops
  32  * for everything else.
  33  */
  34 struct dma_map_ops swiotlb_dma_ops = {
  35         .alloc_coherent = dma_direct_alloc_coherent,
  36         .free_coherent = dma_direct_free_coherent,
  37         .map_sg = swiotlb_map_sg_attrs,
  38         .unmap_sg = swiotlb_unmap_sg_attrs,
  39         .dma_supported = swiotlb_dma_supported,
  40         .map_page = swiotlb_map_page,
  41         .unmap_page = swiotlb_unmap_page,
  42         .sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
  43         .sync_single_range_for_device = swiotlb_sync_single_range_for_device,
  44         .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
  45         .sync_sg_for_device = swiotlb_sync_sg_for_device,
  46         .mapping_error = swiotlb_dma_mapping_error,
  47 };
  48
  49 void pci_dma_dev_setup_swiotlb(struct pci_dev *pdev)
  50 {
  51         struct pci_controller *hose;
  52         struct dev_archdata *sd;
  53
  54         hose = pci_bus_to_host(pdev->bus);
  55         sd = &pdev->dev.archdata;
  56         sd->max_direct_dma_addr =
  57                 hose->dma_window_base_cur + hose->dma_window_size;
  58 }
  59
  60 static int ppc_swiotlb_bus_notify(struct notifier_block *nb,
  61                                   unsigned long action, void *data)
  62 {
  63         struct device *dev = data;
  64         struct dev_archdata *sd;
  65
  66         /* We are only intereted in device addition */
  67         if (action != BUS_NOTIFY_ADD_DEVICE)
  68                 return 0;
  69
  70         sd = &dev->archdata;
  71         sd->max_direct_dma_addr = 0;
  72
  73         /* May need to bounce if the device can't address all of DRAM */
  74         if (dma_get_mask(dev) < lmb_end_of_DRAM())
  75                 set_dma_ops(dev, &swiotlb_dma_ops);
  76
  77         return NOTIFY_DONE;
  78 }
  79
  80 static struct notifier_block ppc_swiotlb_plat_bus_notifier = {
  81         .notifier_call = ppc_swiotlb_bus_notify,
  82         .priority = 0,
  83 };
  84
  85 static struct notifier_block ppc_swiotlb_of_bus_notifier = {
  86         .notifier_call = ppc_swiotlb_bus_notify,
  87         .priority = 0,
  88 };
  89
  90 int __init swiotlb_setup_bus_notifier(void)
  91 {
  92         bus_register_notifier(&platform_bus_type,
  93                               &ppc_swiotlb_plat_bus_notifier);
  94         bus_register_notifier(&of_platform_bus_type,
  95                               &ppc_swiotlb_of_bus_notifier);
  96
  97         return 0;
  98 }