drivers/dma/ioat.c

   1 /*
   2  * Intel I/OAT DMA Linux driver
   3  * Copyright(c) 2007 Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * The full GNU General Public License is included in this distribution in
  19  * the file called "COPYING".
  20  *
  21  */
  22
  23 /*
  24  * This driver supports an Intel I/OAT DMA engine, which does asynchronous
  25  * copy operations.
  26  */
  27
  28 #include <linux/init.h>
  29 #include <linux/module.h>
  30 #include <linux/pci.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/dca.h>
  33 #include "ioatdma.h"
  34 #include "ioatdma_registers.h"
  35 #include "ioatdma_hw.h"
  36
  37 MODULE_VERSION("1.24");
  38 MODULE_LICENSE("GPL");
  39 MODULE_AUTHOR("Intel Corporation");
  40
  41 static struct pci_device_id ioat_pci_tbl[] = {
  42         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT) },
  43         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_CNB)  },
  44         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_SCNB) },
  45         { PCI_DEVICE(PCI_VENDOR_ID_UNISYS, PCI_DEVICE_ID_UNISYS_DMA_DIRECTOR) },
  46         { 0, }
  47 };
  48
  49 struct ioat_device {
  50         struct pci_dev          *pdev;
  51         void __iomem            *iobase;
  52         struct ioatdma_device   *dma;
  53         struct dca_provider     *dca;
  54 };
  55
  56 static int __devinit ioat_probe(struct pci_dev *pdev,
  57                                 const struct pci_device_id *id);
  58 #ifdef IOAT_DMA_REMOVE
  59 static void __devexit ioat_remove(struct pci_dev *pdev);
  60 #endif
  61
  62 static int ioat_dca_enabled = 1;
  63 module_param(ioat_dca_enabled, int, 0644);
  64 MODULE_PARM_DESC(ioat_dca_enabled, "control support of dca service (default: 1)");
  65
  66 static int ioat_setup_functionality(struct pci_dev *pdev, void __iomem *iobase)
  67 {
  68         struct ioat_device *device = pci_get_drvdata(pdev);
  69         u8 version;
  70         int err = 0;
  71
  72         version = readb(iobase + IOAT_VER_OFFSET);
  73         switch (version) {
  74         case IOAT_VER_1_2:
  75                 device->dma = ioat_dma_probe(pdev, iobase);
  76                 if (ioat_dca_enabled)
  77                         device->dca = ioat_dca_init(pdev, iobase);
  78                 break;
  79         default:
  80                 err = -ENODEV;
  81                 break;
  82         }
  83         return err;
  84 }
  85
  86 static void ioat_shutdown_functionality(struct pci_dev *pdev)
  87 {
  88         struct ioat_device *device = pci_get_drvdata(pdev);
  89
  90         if (device->dma) {
  91                 ioat_dma_remove(device->dma);
  92                 device->dma = NULL;
  93         }
  94
  95         if (device->dca) {
  96                 unregister_dca_provider(device->dca);
  97                 free_dca_provider(device->dca);
  98                 device->dca = NULL;
  99         }
 100
 101 }
 102
 103 static struct pci_driver ioat_pci_drv = {
 104         .name           = "ioatdma",
 105         .id_table       = ioat_pci_tbl,
 106         .probe          = ioat_probe,
 107         .shutdown       = ioat_shutdown_functionality,
 108 #ifdef IOAT_DMA_REMOVE
 109         .remove         = __devexit_p(ioat_remove),
 110 #endif
 111 };
 112
 113 static int __devinit ioat_probe(struct pci_dev *pdev,
 114                                 const struct pci_device_id *id)
 115 {
 116         void __iomem *iobase;
 117         struct ioat_device *device;
 118         unsigned long mmio_start, mmio_len;
 119         int err;
 120
 121         err = pci_enable_device(pdev);
 122         if (err)
 123                 goto err_enable_device;
 124
 125         err = pci_request_regions(pdev, ioat_pci_drv.name);
 126         if (err)
 127                 goto err_request_regions;
 128
 129         err = pci_set_dma_mask(pdev, DMA_64BIT_MASK);
 130         if (err)
 131                 err = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
 132         if (err)
 133                 goto err_set_dma_mask;
 134
 135         err = pci_set_consistent_dma_mask(pdev, DMA_64BIT_MASK);
 136         if (err)
 137                 err = pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK);
 138         if (err)
 139                 goto err_set_dma_mask;
 140
 141         mmio_start = pci_resource_start(pdev, 0);
 142         mmio_len = pci_resource_len(pdev, 0);
 143         iobase = ioremap(mmio_start, mmio_len);
 144         if (!iobase) {
 145                 err = -ENOMEM;
 146                 goto err_ioremap;
 147         }
 148
 149         device = kzalloc(sizeof(*device), GFP_KERNEL);
 150         if (!device) {
 151                 err = -ENOMEM;
 152                 goto err_kzalloc;
 153         }
 154         device->pdev = pdev;
 155         pci_set_drvdata(pdev, device);
 156         device->iobase = iobase;
 157
 158         pci_set_master(pdev);
 159
 160         err = ioat_setup_functionality(pdev, iobase);
 161         if (err)
 162                 goto err_version;
 163
 164         return 0;
 165
 166 err_version:
 167         kfree(device);
 168 err_kzalloc:
 169         iounmap(iobase);
 170 err_ioremap:
 171 err_set_dma_mask:
 172         pci_release_regions(pdev);
 173         pci_disable_device(pdev);
 174 err_request_regions:
 175 err_enable_device:
 176         return err;
 177 }
 178
 179 #ifdef IOAT_DMA_REMOVE
 180 /*
 181  * It is unsafe to remove this module: if removed while a requested
 182  * dma is outstanding, esp. from tcp, it is possible to hang while
 183  * waiting for something that will never finish, thus hanging at
 184  * least one cpu.  However, if you're feeling lucky and need to do
 185  * some testing, this usually works just fine.
 186  */
 187 static void __devexit ioat_remove(struct pci_dev *pdev)
 188 {
 189         struct ioat_device *device = pci_get_drvdata(pdev);
 190
 191         ioat_shutdown_functionality(pdev);
 192
 193         kfree(device);
 194
 195         iounmap(device->iobase);
 196         pci_release_regions(pdev);
 197         pci_disable_device(pdev);
 198 }
 199 #endif
 200
 201 static int __init ioat_init_module(void)
 202 {
 203         return pci_register_driver(&ioat_pci_drv);
 204 }
 205 module_init(ioat_init_module);
 206
 207 static void __exit ioat_exit_module(void)
 208 {
 209         pci_unregister_driver(&ioat_pci_drv);
 210 }
 211 module_exit(ioat_exit_module);