release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/scsi/ibmvscsi/rpa_vscsi.c

   1 /* ------------------------------------------------------------
   2  * rpa_vscsi.c
   3  * (C) Copyright IBM Corporation 1994, 2003
   4  * Authors: Colin DeVilbiss (devilbis@us.ibm.com)
   5  *          Santiago Leon (santil@us.ibm.com)
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
  20  * USA
  21  *
  22  * ------------------------------------------------------------
  23  * RPA-specific functions of the SCSI host adapter for Virtual I/O devices
  24  *
  25  * This driver allows the Linux SCSI peripheral drivers to directly
  26  * access devices in the hosting partition, either on an iSeries
  27  * hypervisor system or a converged hypervisor system.
  28  */
  29
  30 #include <asm/vio.h>
  31 #include <asm/prom.h>
  32 #include <asm/iommu.h>
  33 #include <asm/hvcall.h>
  34 #include <linux/delay.h>
  35 #include <linux/dma-mapping.h>
  36 #include <linux/gfp.h>
  37 #include <linux/interrupt.h>
  38 #include "ibmvscsi.h"
  39
  40 static char partition_name[97] = "UNKNOWN";
  41 static unsigned int partition_number = -1;
  42
  43 /* ------------------------------------------------------------
  44  * Routines for managing the command/response queue
  45  */
  46 /**
  47  * rpavscsi_handle_event: - Interrupt handler for crq events
  48  * @irq:        number of irq to handle, not used
  49  * @dev_instance: ibmvscsi_host_data of host that received interrupt
  50  *
  51  * Disables interrupts and schedules srp_task
  52  * Always returns IRQ_HANDLED
  53  */
  54 static irqreturn_t rpavscsi_handle_event(int irq, void *dev_instance)
  55 {
  56         struct ibmvscsi_host_data *hostdata =
  57             (struct ibmvscsi_host_data *)dev_instance;
  58         vio_disable_interrupts(to_vio_dev(hostdata->dev));
  59         tasklet_schedule(&hostdata->srp_task);
  60         return IRQ_HANDLED;
  61 }
  62
  63 /**
  64  * release_crq_queue: - Deallocates data and unregisters CRQ
  65  * @queue:      crq_queue to initialize and register
  66  * @host_data:  ibmvscsi_host_data of host
  67  *
  68  * Frees irq, deallocates a page for messages, unmaps dma, and unregisters
  69  * the crq with the hypervisor.
  70  */
  71 static void rpavscsi_release_crq_queue(struct crq_queue *queue,
  72                                        struct ibmvscsi_host_data *hostdata,
  73                                        int max_requests)
  74 {
  75         long rc = 0;
  76         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
  77         free_irq(vdev->irq, (void *)hostdata);
  78         tasklet_kill(&hostdata->srp_task);
  79         do {
  80                 if (rc)
  81                         msleep(100);
  82                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
  83         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
  84         dma_unmap_single(hostdata->dev,
  85                          queue->msg_token,
  86                          queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
  87         free_page((unsigned long)queue->msgs);
  88 }
  89
  90 /**
  91  * crq_queue_next_crq: - Returns the next entry in message queue
  92  * @queue:      crq_queue to use
  93  *
  94  * Returns pointer to next entry in queue, or NULL if there are no new
  95  * entried in the CRQ.
  96  */
  97 static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
  98 {
  99         struct viosrp_crq *crq;
 100         unsigned long flags;
 101
 102         spin_lock_irqsave(&queue->lock, flags);
 103         crq = &queue->msgs[queue->cur];
 104         if (crq->valid & 0x80) {
 105                 if (++queue->cur == queue->size)
 106                         queue->cur = 0;
 107         } else
 108                 crq = NULL;
 109         spin_unlock_irqrestore(&queue->lock, flags);
 110
 111         return crq;
 112 }
 113
 114 /**
 115  * rpavscsi_send_crq: - Send a CRQ
 116  * @hostdata:   the adapter
 117  * @word1:      the first 64 bits of the data
 118  * @word2:      the second 64 bits of the data
 119  */
 120 static int rpavscsi_send_crq(struct ibmvscsi_host_data *hostdata,
 121                              u64 word1, u64 word2)
 122 {
 123         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 124
 125         return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
 126 }
 127
 128 /**
 129  * rpavscsi_task: - Process srps asynchronously
 130  * @data:       ibmvscsi_host_data of host
 131  */
 132 static void rpavscsi_task(void *data)
 133 {
 134         struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
 135         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 136         struct viosrp_crq *crq;
 137         int done = 0;
 138
 139         while (!done) {
 140                 /* Pull all the valid messages off the CRQ */
 141                 while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 142                         ibmvscsi_handle_crq(crq, hostdata);
 143                         crq->valid = 0x00;
 144                 }
 145
 146                 vio_enable_interrupts(vdev);
 147                 if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 148                         vio_disable_interrupts(vdev);
 149                         ibmvscsi_handle_crq(crq, hostdata);
 150                         crq->valid = 0x00;
 151                 } else {
 152                         done = 1;
 153                 }
 154         }
 155 }
 156
 157 static void gather_partition_info(void)
 158 {
 159         struct device_node *rootdn;
 160
 161         const char *ppartition_name;
 162         const unsigned int *p_number_ptr;
 163
 164         /* Retrieve information about this partition */
 165         rootdn = of_find_node_by_path("/");
 166         if (!rootdn) {
 167                 return;
 168         }
 169
 170         ppartition_name = of_get_property(rootdn, "ibm,partition-name", NULL);
 171         if (ppartition_name)
 172                 strncpy(partition_name, ppartition_name,
 173                                 sizeof(partition_name));
 174         p_number_ptr = of_get_property(rootdn, "ibm,partition-no", NULL);
 175         if (p_number_ptr)
 176                 partition_number = *p_number_ptr;
 177         of_node_put(rootdn);
 178 }
 179
 180 static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
 181 {
 182         memset(&hostdata->madapter_info, 0x00,
 183                         sizeof(hostdata->madapter_info));
 184
 185         dev_info(hostdata->dev, "SRP_VERSION: %s\n", SRP_VERSION);
 186         strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);
 187
 188         strncpy(hostdata->madapter_info.partition_name, partition_name,
 189                         sizeof(hostdata->madapter_info.partition_name));
 190
 191         hostdata->madapter_info.partition_number = partition_number;
 192
 193         hostdata->madapter_info.mad_version = 1;
 194         hostdata->madapter_info.os_type = 2;
 195 }
 196
 197 /**
 198  * reset_crq_queue: - resets a crq after a failure
 199  * @queue:      crq_queue to initialize and register
 200  * @hostdata:   ibmvscsi_host_data of host
 201  *
 202  */
 203 static int rpavscsi_reset_crq_queue(struct crq_queue *queue,
 204                                     struct ibmvscsi_host_data *hostdata)
 205 {
 206         int rc = 0;
 207         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 208
 209         /* Close the CRQ */
 210         do {
 211                 if (rc)
 212                         msleep(100);
 213                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 214         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 215
 216         /* Clean out the queue */
 217         memset(queue->msgs, 0x00, PAGE_SIZE);
 218         queue->cur = 0;
 219
 220         set_adapter_info(hostdata);
 221
 222         /* And re-open it again */
 223         rc = plpar_hcall_norets(H_REG_CRQ,
 224                                 vdev->unit_address,
 225                                 queue->msg_token, PAGE_SIZE);
 226         if (rc == 2) {
 227                 /* Adapter is good, but other end is not ready */
 228                 dev_warn(hostdata->dev, "Partner adapter not ready\n");
 229         } else if (rc != 0) {
 230                 dev_warn(hostdata->dev, "couldn't register crq--rc 0x%x\n", rc);
 231         }
 232         return rc;
 233 }
 234
 235 /**
 236  * initialize_crq_queue: - Initializes and registers CRQ with hypervisor
 237  * @queue:      crq_queue to initialize and register
 238  * @hostdata:   ibmvscsi_host_data of host
 239  *
 240  * Allocates a page for messages, maps it for dma, and registers
 241  * the crq with the hypervisor.
 242  * Returns zero on success.
 243  */
 244 static int rpavscsi_init_crq_queue(struct crq_queue *queue,
 245                                    struct ibmvscsi_host_data *hostdata,
 246                                    int max_requests)
 247 {
 248         int rc;
 249         int retrc;
 250         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 251
 252         queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
 253
 254         if (!queue->msgs)
 255                 goto malloc_failed;
 256         queue->size = PAGE_SIZE / sizeof(*queue->msgs);
 257
 258         queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
 259                                           queue->size * sizeof(*queue->msgs),
 260                                           DMA_BIDIRECTIONAL);
 261
 262         if (dma_mapping_error(hostdata->dev, queue->msg_token))
 263                 goto map_failed;
 264
 265         gather_partition_info();
 266         set_adapter_info(hostdata);
 267
 268         retrc = rc = plpar_hcall_norets(H_REG_CRQ,
 269                                 vdev->unit_address,
 270                                 queue->msg_token, PAGE_SIZE);
 271         if (rc == H_RESOURCE)
 272                 /* maybe kexecing and resource is busy. try a reset */
 273                 rc = rpavscsi_reset_crq_queue(queue,
 274                                               hostdata);
 275
 276         if (rc == 2) {
 277                 /* Adapter is good, but other end is not ready */
 278                 dev_warn(hostdata->dev, "Partner adapter not ready\n");
 279                 retrc = 0;
 280         } else if (rc != 0) {
 281                 dev_warn(hostdata->dev, "Error %d opening adapter\n", rc);
 282                 goto reg_crq_failed;
 283         }
 284
 285         queue->cur = 0;
 286         spin_lock_init(&queue->lock);
 287
 288         tasklet_init(&hostdata->srp_task, (void *)rpavscsi_task,
 289                      (unsigned long)hostdata);
 290
 291         if (request_irq(vdev->irq,
 292                         rpavscsi_handle_event,
 293                         0, "ibmvscsi", (void *)hostdata) != 0) {
 294                 dev_err(hostdata->dev, "couldn't register irq 0x%x\n",
 295                         vdev->irq);
 296                 goto req_irq_failed;
 297         }
 298
 299         rc = vio_enable_interrupts(vdev);
 300         if (rc != 0) {
 301                 dev_err(hostdata->dev, "Error %d enabling interrupts!!!\n", rc);
 302                 goto req_irq_failed;
 303         }
 304
 305         return retrc;
 306
 307       req_irq_failed:
 308         tasklet_kill(&hostdata->srp_task);
 309         rc = 0;
 310         do {
 311                 if (rc)
 312                         msleep(100);
 313                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 314         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 315       reg_crq_failed:
 316         dma_unmap_single(hostdata->dev,
 317                          queue->msg_token,
 318                          queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
 319       map_failed:
 320         free_page((unsigned long)queue->msgs);
 321       malloc_failed:
 322         return -1;
 323 }
 324
 325 /**
 326  * reenable_crq_queue: - reenables a crq after
 327  * @queue:      crq_queue to initialize and register
 328  * @hostdata:   ibmvscsi_host_data of host
 329  *
 330  */
 331 static int rpavscsi_reenable_crq_queue(struct crq_queue *queue,
 332                                        struct ibmvscsi_host_data *hostdata)
 333 {
 334         int rc = 0;
 335         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 336
 337         /* Re-enable the CRQ */
 338         do {
 339                 if (rc)
 340                         msleep(100);
 341                 rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
 342         } while ((rc == H_IN_PROGRESS) || (rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 343
 344         if (rc)
 345                 dev_err(hostdata->dev, "Error %d enabling adapter\n", rc);
 346         return rc;
 347 }
 348
 349 /**
 350  * rpavscsi_resume: - resume after suspend
 351  * @hostdata:   ibmvscsi_host_data of host
 352  *
 353  */
 354 static int rpavscsi_resume(struct ibmvscsi_host_data *hostdata)
 355 {
 356         vio_disable_interrupts(to_vio_dev(hostdata->dev));
 357         tasklet_schedule(&hostdata->srp_task);
 358         return 0;
 359 }
 360
 361 struct ibmvscsi_ops rpavscsi_ops = {
 362         .init_crq_queue = rpavscsi_init_crq_queue,
 363         .release_crq_queue = rpavscsi_release_crq_queue,
 364         .reset_crq_queue = rpavscsi_reset_crq_queue,
 365         .reenable_crq_queue = rpavscsi_reenable_crq_queue,
 366         .send_crq = rpavscsi_send_crq,
 367         .resume = rpavscsi_resume,
 368 };