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  * @regs:       pt_regs with registers
  49  *
  50  * Disables interrupts and schedules srp_task
  51  * Always returns IRQ_HANDLED
  52  */
  53 static irqreturn_t ibmvscsi_handle_event(int irq,
  54                                          void *dev_instance,
  55                                          struct pt_regs *regs)
  56 {
  57         struct ibmvscsi_host_data *hostdata =
  58             (struct ibmvscsi_host_data *)dev_instance;
  59         vio_disable_interrupts(to_vio_dev(hostdata->dev));
  60         tasklet_schedule(&hostdata->srp_task);
  61         return IRQ_HANDLED;
  62 }
  63
  64 /**
  65  * release_crq_queue: - Deallocates data and unregisters CRQ
  66  * @queue:      crq_queue to initialize and register
  67  * @host_data:  ibmvscsi_host_data of host
  68  *
  69  * Frees irq, deallocates a page for messages, unmaps dma, and unregisters
  70  * the crq with the hypervisor.
  71  */
  72 void ibmvscsi_release_crq_queue(struct crq_queue *queue,
  73                                 struct ibmvscsi_host_data *hostdata,
  74                                 int max_requests)
  75 {
  76         long rc;
  77         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
  78         free_irq(vdev->irq, (void *)hostdata);
  79         tasklet_kill(&hostdata->srp_task);
  80         do {
  81                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
  82         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
  83         dma_unmap_single(hostdata->dev,
  84                          queue->msg_token,
  85                          queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
  86         free_page((unsigned long)queue->msgs);
  87 }
  88
  89 /**
  90  * crq_queue_next_crq: - Returns the next entry in message queue
  91  * @queue:      crq_queue to use
  92  *
  93  * Returns pointer to next entry in queue, or NULL if there are no new
  94  * entried in the CRQ.
  95  */
  96 static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
  97 {
  98         struct viosrp_crq *crq;
  99         unsigned long flags;
 100
 101         spin_lock_irqsave(&queue->lock, flags);
 102         crq = &queue->msgs[queue->cur];
 103         if (crq->valid & 0x80) {
 104                 if (++queue->cur == queue->size)
 105                         queue->cur = 0;
 106         } else
 107                 crq = NULL;
 108         spin_unlock_irqrestore(&queue->lock, flags);
 109
 110         return crq;
 111 }
 112
 113 /**
 114  * ibmvscsi_send_crq: - Send a CRQ
 115  * @hostdata:   the adapter
 116  * @word1:      the first 64 bits of the data
 117  * @word2:      the second 64 bits of the data
 118  */
 119 int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata, u64 word1, u64 word2)
 120 {
 121         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 122
 123         return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
 124 }
 125
 126 /**
 127  * ibmvscsi_task: - Process srps asynchronously
 128  * @data:       ibmvscsi_host_data of host
 129  */
 130 static void ibmvscsi_task(void *data)
 131 {
 132         struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
 133         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 134         struct viosrp_crq *crq;
 135         int done = 0;
 136
 137         while (!done) {
 138                 /* Pull all the valid messages off the CRQ */
 139                 while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 140                         ibmvscsi_handle_crq(crq, hostdata);
 141                         crq->valid = 0x00;
 142                 }
 143
 144                 vio_enable_interrupts(vdev);
 145                 if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 146                         vio_disable_interrupts(vdev);
 147                         ibmvscsi_handle_crq(crq, hostdata);
 148                         crq->valid = 0x00;
 149                 } else {
 150                         done = 1;
 151                 }
 152         }
 153 }
 154
 155 static void gather_partition_info(void)
 156 {
 157         struct device_node *rootdn;
 158
 159         char *ppartition_name;
 160         unsigned int *p_number_ptr;
 161
 162         /* Retrieve information about this partition */
 163         rootdn = find_path_device("/");
 164         if (!rootdn) {
 165                 return;
 166         }
 167
 168         ppartition_name =
 169                 get_property(rootdn, "ibm,partition-name", NULL);
 170         if (ppartition_name)
 171                 strncpy(partition_name, ppartition_name,
 172                                 sizeof(partition_name));
 173         p_number_ptr =
 174                 (unsigned int *)get_property(rootdn, "ibm,partition-no",
 175                                              NULL);
 176         if (p_number_ptr)
 177                 partition_number = *p_number_ptr;
 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         printk(KERN_INFO "rpa_vscsi: SPR_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  * initialize_crq_queue: - Initializes and registers CRQ with hypervisor
 199  * @queue:      crq_queue to initialize and register
 200  * @hostdata:   ibmvscsi_host_data of host
 201  *
 202  * Allocates a page for messages, maps it for dma, and registers
 203  * the crq with the hypervisor.
 204  * Returns zero on success.
 205  */
 206 int ibmvscsi_init_crq_queue(struct crq_queue *queue,
 207                             struct ibmvscsi_host_data *hostdata,
 208                             int max_requests)
 209 {
 210         int rc;
 211         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 212
 213         queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
 214
 215         if (!queue->msgs)
 216                 goto malloc_failed;
 217         queue->size = PAGE_SIZE / sizeof(*queue->msgs);
 218
 219         queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
 220                                           queue->size * sizeof(*queue->msgs),
 221                                           DMA_BIDIRECTIONAL);
 222
 223         if (dma_mapping_error(queue->msg_token))
 224                 goto map_failed;
 225
 226         gather_partition_info();
 227         set_adapter_info(hostdata);
 228
 229         rc = plpar_hcall_norets(H_REG_CRQ,
 230                                 vdev->unit_address,
 231                                 queue->msg_token, PAGE_SIZE);
 232         if (rc == H_RESOURCE)
 233                 /* maybe kexecing and resource is busy. try a reset */
 234                 rc = ibmvscsi_reset_crq_queue(queue,
 235                                               hostdata);
 236
 237         if (rc == 2) {
 238                 /* Adapter is good, but other end is not ready */
 239                 printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
 240         } else if (rc != 0) {
 241                 printk(KERN_WARNING "ibmvscsi: Error %d opening adapter\n", rc);
 242                 goto reg_crq_failed;
 243         }
 244
 245         if (request_irq(vdev->irq,
 246                         ibmvscsi_handle_event,
 247                         0, "ibmvscsi", (void *)hostdata) != 0) {
 248                 printk(KERN_ERR "ibmvscsi: couldn't register irq 0x%x\n",
 249                        vdev->irq);
 250                 goto req_irq_failed;
 251         }
 252
 253         rc = vio_enable_interrupts(vdev);
 254         if (rc != 0) {
 255                 printk(KERN_ERR "ibmvscsi:  Error %d enabling interrupts!!!\n",
 256                        rc);
 257                 goto req_irq_failed;
 258         }
 259
 260         queue->cur = 0;
 261         spin_lock_init(&queue->lock);
 262
 263         tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
 264                      (unsigned long)hostdata);
 265
 266         return 0;
 267
 268       req_irq_failed:
 269         do {
 270                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 271         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 272       reg_crq_failed:
 273         dma_unmap_single(hostdata->dev,
 274                          queue->msg_token,
 275                          queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
 276       map_failed:
 277         free_page((unsigned long)queue->msgs);
 278       malloc_failed:
 279         return -1;
 280 }
 281
 282 /**
 283  * reenable_crq_queue: - reenables a crq after
 284  * @queue:      crq_queue to initialize and register
 285  * @hostdata:   ibmvscsi_host_data of host
 286  *
 287  */
 288 int ibmvscsi_reenable_crq_queue(struct crq_queue *queue,
 289                                  struct ibmvscsi_host_data *hostdata)
 290 {
 291         int rc;
 292         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 293
 294         /* Re-enable the CRQ */
 295         do {
 296                 rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
 297         } while ((rc == H_IN_PROGRESS) || (rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 298
 299         if (rc)
 300                 printk(KERN_ERR "ibmvscsi: Error %d enabling adapter\n", rc);
 301         return rc;
 302 }
 303
 304 /**
 305  * reset_crq_queue: - resets a crq after a failure
 306  * @queue:      crq_queue to initialize and register
 307  * @hostdata:   ibmvscsi_host_data of host
 308  *
 309  */
 310 int ibmvscsi_reset_crq_queue(struct crq_queue *queue,
 311                               struct ibmvscsi_host_data *hostdata)
 312 {
 313         int rc;
 314         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 315
 316         /* Close the CRQ */
 317         do {
 318                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 319         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 320
 321         /* Clean out the queue */
 322         memset(queue->msgs, 0x00, PAGE_SIZE);
 323         queue->cur = 0;
 324
 325         set_adapter_info(hostdata);
 326
 327         /* And re-open it again */
 328         rc = plpar_hcall_norets(H_REG_CRQ,
 329                                 vdev->unit_address,
 330                                 queue->msg_token, PAGE_SIZE);
 331         if (rc == 2) {
 332                 /* Adapter is good, but other end is not ready */
 333                 printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
 334         } else if (rc != 0) {
 335                 printk(KERN_WARNING
 336                        "ibmvscsi: couldn't register crq--rc 0x%x\n", rc);
 337         }
 338         return rc;
 339 }