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(IOAT_DMA_VERSION);
  38 MODULE_LICENSE("GPL");
  39 MODULE_AUTHOR("Intel Corporation");
  40
  41 static struct pci_device_id ioat_pci_tbl[] = {
  42         /* I/OAT v1 platforms */
  43         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT) },
  44         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_CNB)  },
  45         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_SCNB) },
  46         { PCI_DEVICE(PCI_VENDOR_ID_UNISYS, PCI_DEVICE_ID_UNISYS_DMA_DIRECTOR) },
  47
  48         /* I/OAT v2 platforms */
  49         { PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IOAT_SNB) },
  50         { 0, }
  51 };
  52
  53 struct ioat_device {
  54         struct pci_dev          *pdev;
  55         void __iomem            *iobase;
  56         struct ioatdma_device   *dma;
  57         struct dca_provider     *dca;
  58 };
  59
  60 static int __devinit ioat_probe(struct pci_dev *pdev,
  61                                 const struct pci_device_id *id);
  62 static void __devexit ioat_remove(struct pci_dev *pdev);
  63
  64 static int ioat_dca_enabled = 1;
  65 module_param(ioat_dca_enabled, int, 0644);
  66 MODULE_PARM_DESC(ioat_dca_enabled, "control support of dca service (default: 1)");
  67
  68 static int ioat_setup_functionality(struct pci_dev *pdev, void __iomem *iobase)
  69 {
  70         struct ioat_device *device = pci_get_drvdata(pdev);
  71         u8 version;
  72         int err = 0;
  73
  74         version = readb(iobase + IOAT_VER_OFFSET);
  75         switch (version) {
  76         case IOAT_VER_1_2:
  77                 device->dma = ioat_dma_probe(pdev, iobase);
  78                 if (device->dma && ioat_dca_enabled)
  79                         device->dca = ioat_dca_init(pdev, iobase);
  80                 break;
  81         case IOAT_VER_2_0:
  82                 device->dma = ioat_dma_probe(pdev, iobase);
  83                 if (device->dma && ioat_dca_enabled)
  84                         device->dca = ioat2_dca_init(pdev, iobase);
  85                 break;
  86         default:
  87                 err = -ENODEV;
  88                 break;
  89         }
  90         if (!device->dma)
  91                 err = -ENODEV;
  92         return err;
  93 }
  94
  95 static void ioat_shutdown_functionality(struct pci_dev *pdev)
  96 {
  97         struct ioat_device *device = pci_get_drvdata(pdev);
  98
  99         dev_err(&pdev->dev, "Removing dma and dca services\n");
 100         if (device->dca) {
 101                 unregister_dca_provider(device->dca);
 102                 free_dca_provider(device->dca);
 103                 device->dca = NULL;
 104         }
 105
 106         if (device->dma) {
 107                 ioat_dma_remove(device->dma);
 108                 device->dma = NULL;
 109         }
 110 }
 111
 112 static struct pci_driver ioat_pci_driver = {
 113         .name           = "ioatdma",
 114         .id_table       = ioat_pci_tbl,
 115         .probe          = ioat_probe,
 116         .shutdown       = ioat_shutdown_functionality,
 117         .remove         = __devexit_p(ioat_remove),
 118 };
 119
 120 static int __devinit ioat_probe(struct pci_dev *pdev,
 121                                 const struct pci_device_id *id)
 122 {
 123         void __iomem *iobase;
 124         struct ioat_device *device;
 125         unsigned long mmio_start, mmio_len;
 126         int err;
 127
 128         err = pci_enable_device(pdev);
 129         if (err)
 130                 goto err_enable_device;
 131
 132         err = pci_request_regions(pdev, ioat_pci_driver.name);
 133         if (err)
 134                 goto err_request_regions;
 135
 136         err = pci_set_dma_mask(pdev, DMA_64BIT_MASK);
 137         if (err)
 138                 err = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
 139         if (err)
 140                 goto err_set_dma_mask;
 141
 142         err = pci_set_consistent_dma_mask(pdev, DMA_64BIT_MASK);
 143         if (err)
 144                 err = pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK);
 145         if (err)
 146                 goto err_set_dma_mask;
 147
 148         mmio_start = pci_resource_start(pdev, 0);
 149         mmio_len = pci_resource_len(pdev, 0);
 150         iobase = ioremap(mmio_start, mmio_len);
 151         if (!iobase) {
 152                 err = -ENOMEM;
 153                 goto err_ioremap;
 154         }
 155
 156         device = kzalloc(sizeof(*device), GFP_KERNEL);
 157         if (!device) {
 158                 err = -ENOMEM;
 159                 goto err_kzalloc;
 160         }
 161         device->pdev = pdev;
 162         pci_set_drvdata(pdev, device);
 163         device->iobase = iobase;
 164
 165         pci_set_master(pdev);
 166
 167         err = ioat_setup_functionality(pdev, iobase);
 168         if (err)
 169                 goto err_version;
 170
 171         return 0;
 172
 173 err_version:
 174         kfree(device);
 175 err_kzalloc:
 176         iounmap(iobase);
 177 err_ioremap:
 178 err_set_dma_mask:
 179         pci_release_regions(pdev);
 180         pci_disable_device(pdev);
 181 err_request_regions:
 182 err_enable_device:
 183         return err;
 184 }
 185
 186 /*
 187  * It is unsafe to remove this module: if removed while a requested
 188  * dma is outstanding, esp. from tcp, it is possible to hang while
 189  * waiting for something that will never finish.  However, if you're
 190  * feeling lucky, this usually works just fine.
 191  */
 192 static void __devexit ioat_remove(struct pci_dev *pdev)
 193 {
 194         struct ioat_device *device = pci_get_drvdata(pdev);
 195
 196         ioat_shutdown_functionality(pdev);
 197
 198         kfree(device);
 199 }
 200
 201 static int __init ioat_init_module(void)
 202 {
 203         return pci_register_driver(&ioat_pci_driver);
 204 }
 205 module_init(ioat_init_module);
 206
 207 static void __exit ioat_exit_module(void)
 208 {
 209         pci_unregister_driver(&ioat_pci_driver);
 210 }
 211 module_exit(ioat_exit_module);