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/dma-mapping.h>
  35 #include <linux/interrupt.h>
  36 #include "ibmvscsi.h"
  37
  38 static char partition_name[97] = "UNKNOWN";
  39 static unsigned int partition_number = -1;
  40
  41 /* ------------------------------------------------------------
  42  * Routines for managing the command/response queue
  43  */
  44 /**
  45  * ibmvscsi_handle_event: - Interrupt handler for crq events
  46  * @irq:        number of irq to handle, not used
  47  * @dev_instance: ibmvscsi_host_data of host that received interrupt
  48  *
  49  * Disables interrupts and schedules srp_task
  50  * Always returns IRQ_HANDLED
  51  */
  52 static irqreturn_t ibmvscsi_handle_event(int irq, void *dev_instance)
  53 {
  54         struct ibmvscsi_host_data *hostdata =
  55             (struct ibmvscsi_host_data *)dev_instance;
  56         vio_disable_interrupts(to_vio_dev(hostdata->dev));
  57         tasklet_schedule(&hostdata->srp_task);
  58         return IRQ_HANDLED;
  59 }
  60
  61 /**
  62  * release_crq_queue: - Deallocates data and unregisters CRQ
  63  * @queue:      crq_queue to initialize and register
  64  * @host_data:  ibmvscsi_host_data of host
  65  *
  66  * Frees irq, deallocates a page for messages, unmaps dma, and unregisters
  67  * the crq with the hypervisor.
  68  */
  69 void ibmvscsi_release_crq_queue(struct crq_queue *queue,
  70                                 struct ibmvscsi_host_data *hostdata,
  71                                 int max_requests)
  72 {
  73         long rc;
  74         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
  75         free_irq(vdev->irq, (void *)hostdata);
  76         tasklet_kill(&hostdata->srp_task);
  77         do {
  78                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
  79         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
  80         dma_unmap_single(hostdata->dev,
  81                          queue->msg_token,
  82                          queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
  83         free_page((unsigned long)queue->msgs);
  84 }
  85
  86 /**
  87  * crq_queue_next_crq: - Returns the next entry in message queue
  88  * @queue:      crq_queue to use
  89  *
  90  * Returns pointer to next entry in queue, or NULL if there are no new
  91  * entried in the CRQ.
  92  */
  93 static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
  94 {
  95         struct viosrp_crq *crq;
  96         unsigned long flags;
  97
  98         spin_lock_irqsave(&queue->lock, flags);
  99         crq = &queue->msgs[queue->cur];
 100         if (crq->valid & 0x80) {
 101                 if (++queue->cur == queue->size)
 102                         queue->cur = 0;
 103         } else
 104                 crq = NULL;
 105         spin_unlock_irqrestore(&queue->lock, flags);
 106
 107         return crq;
 108 }
 109
 110 /**
 111  * ibmvscsi_send_crq: - Send a CRQ
 112  * @hostdata:   the adapter
 113  * @word1:      the first 64 bits of the data
 114  * @word2:      the second 64 bits of the data
 115  */
 116 int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata, u64 word1, u64 word2)
 117 {
 118         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 119
 120         return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
 121 }
 122
 123 /**
 124  * ibmvscsi_task: - Process srps asynchronously
 125  * @data:       ibmvscsi_host_data of host
 126  */
 127 static void ibmvscsi_task(void *data)
 128 {
 129         struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
 130         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 131         struct viosrp_crq *crq;
 132         int done = 0;
 133
 134         while (!done) {
 135                 /* Pull all the valid messages off the CRQ */
 136                 while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 137                         ibmvscsi_handle_crq(crq, hostdata);
 138                         crq->valid = 0x00;
 139                 }
 140
 141                 vio_enable_interrupts(vdev);
 142                 if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 143                         vio_disable_interrupts(vdev);
 144                         ibmvscsi_handle_crq(crq, hostdata);
 145                         crq->valid = 0x00;
 146                 } else {
 147                         done = 1;
 148                 }
 149         }
 150 }
 151
 152 static void gather_partition_info(void)
 153 {
 154         struct device_node *rootdn;
 155
 156         const char *ppartition_name;
 157         const unsigned int *p_number_ptr;
 158
 159         /* Retrieve information about this partition */
 160         rootdn = find_path_device("/");
 161         if (!rootdn) {
 162                 return;
 163         }
 164
 165         ppartition_name = get_property(rootdn, "ibm,partition-name", NULL);
 166         if (ppartition_name)
 167                 strncpy(partition_name, ppartition_name,
 168                                 sizeof(partition_name));
 169         p_number_ptr = get_property(rootdn, "ibm,partition-no", NULL);
 170         if (p_number_ptr)
 171                 partition_number = *p_number_ptr;
 172 }
 173
 174 static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
 175 {
 176         memset(&hostdata->madapter_info, 0x00,
 177                         sizeof(hostdata->madapter_info));
 178
 179         printk(KERN_INFO "rpa_vscsi: SPR_VERSION: %s\n", SRP_VERSION);
 180         strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);
 181
 182         strncpy(hostdata->madapter_info.partition_name, partition_name,
 183                         sizeof(hostdata->madapter_info.partition_name));
 184
 185         hostdata->madapter_info.partition_number = partition_number;
 186
 187         hostdata->madapter_info.mad_version = 1;
 188         hostdata->madapter_info.os_type = 2;
 189 }
 190
 191 /**
 192  * initialize_crq_queue: - Initializes and registers CRQ with hypervisor
 193  * @queue:      crq_queue to initialize and register
 194  * @hostdata:   ibmvscsi_host_data of host
 195  *
 196  * Allocates a page for messages, maps it for dma, and registers
 197  * the crq with the hypervisor.
 198  * Returns zero on success.
 199  */
 200 int ibmvscsi_init_crq_queue(struct crq_queue *queue,
 201                             struct ibmvscsi_host_data *hostdata,
 202                             int max_requests)
 203 {
 204         int rc;
 205         int retrc;
 206         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 207
 208         queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
 209
 210         if (!queue->msgs)
 211                 goto malloc_failed;
 212         queue->size = PAGE_SIZE / sizeof(*queue->msgs);
 213
 214         queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
 215                                           queue->size * sizeof(*queue->msgs),
 216                                           DMA_BIDIRECTIONAL);
 217
 218         if (dma_mapping_error(queue->msg_token))
 219                 goto map_failed;
 220
 221         gather_partition_info();
 222         set_adapter_info(hostdata);
 223
 224         retrc = rc = plpar_hcall_norets(H_REG_CRQ,
 225                                 vdev->unit_address,
 226                                 queue->msg_token, PAGE_SIZE);
 227         if (rc == H_RESOURCE)
 228                 /* maybe kexecing and resource is busy. try a reset */
 229                 rc = ibmvscsi_reset_crq_queue(queue,
 230                                               hostdata);
 231
 232         if (rc == 2) {
 233                 /* Adapter is good, but other end is not ready */
 234                 printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
 235                 retrc = 0;
 236         } else if (rc != 0) {
 237                 printk(KERN_WARNING "ibmvscsi: Error %d opening adapter\n", rc);
 238                 goto reg_crq_failed;
 239         }
 240
 241         if (request_irq(vdev->irq,
 242                         ibmvscsi_handle_event,
 243                         0, "ibmvscsi", (void *)hostdata) != 0) {
 244                 printk(KERN_ERR "ibmvscsi: couldn't register irq 0x%x\n",
 245                        vdev->irq);
 246                 goto req_irq_failed;
 247         }
 248
 249         rc = vio_enable_interrupts(vdev);
 250         if (rc != 0) {
 251                 printk(KERN_ERR "ibmvscsi:  Error %d enabling interrupts!!!\n",
 252                        rc);
 253                 goto req_irq_failed;
 254         }
 255
 256         queue->cur = 0;
 257         spin_lock_init(&queue->lock);
 258
 259         tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
 260                      (unsigned long)hostdata);
 261
 262         return retrc;
 263
 264       req_irq_failed:
 265         do {
 266                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 267         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 268       reg_crq_failed:
 269         dma_unmap_single(hostdata->dev,
 270                          queue->msg_token,
 271                          queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
 272       map_failed:
 273         free_page((unsigned long)queue->msgs);
 274       malloc_failed:
 275         return -1;
 276 }
 277
 278 /**
 279  * reenable_crq_queue: - reenables a crq after
 280  * @queue:      crq_queue to initialize and register
 281  * @hostdata:   ibmvscsi_host_data of host
 282  *
 283  */
 284 int ibmvscsi_reenable_crq_queue(struct crq_queue *queue,
 285                                  struct ibmvscsi_host_data *hostdata)
 286 {
 287         int rc;
 288         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 289
 290         /* Re-enable the CRQ */
 291         do {
 292                 rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
 293         } while ((rc == H_IN_PROGRESS) || (rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 294
 295         if (rc)
 296                 printk(KERN_ERR "ibmvscsi: Error %d enabling adapter\n", rc);
 297         return rc;
 298 }
 299
 300 /**
 301  * reset_crq_queue: - resets a crq after a failure
 302  * @queue:      crq_queue to initialize and register
 303  * @hostdata:   ibmvscsi_host_data of host
 304  *
 305  */
 306 int ibmvscsi_reset_crq_queue(struct crq_queue *queue,
 307                               struct ibmvscsi_host_data *hostdata)
 308 {
 309         int rc;
 310         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 311
 312         /* Close the CRQ */
 313         do {
 314                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 315         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 316
 317         /* Clean out the queue */
 318         memset(queue->msgs, 0x00, PAGE_SIZE);
 319         queue->cur = 0;
 320
 321         set_adapter_info(hostdata);
 322
 323         /* And re-open it again */
 324         rc = plpar_hcall_norets(H_REG_CRQ,
 325                                 vdev->unit_address,
 326                                 queue->msg_token, PAGE_SIZE);
 327         if (rc == 2) {
 328                 /* Adapter is good, but other end is not ready */
 329                 printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
 330         } else if (rc != 0) {
 331                 printk(KERN_WARNING
 332                        "ibmvscsi: couldn't register crq--rc 0x%x\n", rc);
 333         }
 334         return rc;
 335 }