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/gfp.h>
  36 #include <linux/interrupt.h>
  37 #include "ibmvscsi.h"
  38
  39 static char partition_name[97] = "UNKNOWN";
  40 static unsigned int partition_number = -1;
  41
  42 /* ------------------------------------------------------------
  43  * Routines for managing the command/response queue
  44  */
  45 /**
  46  * rpavscsi_handle_event: - Interrupt handler for crq events
  47  * @irq:        number of irq to handle, not used
  48  * @dev_instance: ibmvscsi_host_data of host that received interrupt
  49  *
  50  * Disables interrupts and schedules srp_task
  51  * Always returns IRQ_HANDLED
  52  */
  53 static irqreturn_t rpavscsi_handle_event(int irq, void *dev_instance)
  54 {
  55         struct ibmvscsi_host_data *hostdata =
  56             (struct ibmvscsi_host_data *)dev_instance;
  57         vio_disable_interrupts(to_vio_dev(hostdata->dev));
  58         tasklet_schedule(&hostdata->srp_task);
  59         return IRQ_HANDLED;
  60 }
  61
  62 /**
  63  * release_crq_queue: - Deallocates data and unregisters CRQ
  64  * @queue:      crq_queue to initialize and register
  65  * @host_data:  ibmvscsi_host_data of host
  66  *
  67  * Frees irq, deallocates a page for messages, unmaps dma, and unregisters
  68  * the crq with the hypervisor.
  69  */
  70 static void rpavscsi_release_crq_queue(struct crq_queue *queue,
  71                                        struct ibmvscsi_host_data *hostdata,
  72                                        int max_requests)
  73 {
  74         long rc;
  75         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
  76         free_irq(vdev->irq, (void *)hostdata);
  77         tasklet_kill(&hostdata->srp_task);
  78         do {
  79                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
  80         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
  81         dma_unmap_single(hostdata->dev,
  82                          queue->msg_token,
  83                          queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
  84         free_page((unsigned long)queue->msgs);
  85 }
  86
  87 /**
  88  * crq_queue_next_crq: - Returns the next entry in message queue
  89  * @queue:      crq_queue to use
  90  *
  91  * Returns pointer to next entry in queue, or NULL if there are no new
  92  * entried in the CRQ.
  93  */
  94 static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
  95 {
  96         struct viosrp_crq *crq;
  97         unsigned long flags;
  98
  99         spin_lock_irqsave(&queue->lock, flags);
 100         crq = &queue->msgs[queue->cur];
 101         if (crq->valid & 0x80) {
 102                 if (++queue->cur == queue->size)
 103                         queue->cur = 0;
 104         } else
 105                 crq = NULL;
 106         spin_unlock_irqrestore(&queue->lock, flags);
 107
 108         return crq;
 109 }
 110
 111 /**
 112  * rpavscsi_send_crq: - Send a CRQ
 113  * @hostdata:   the adapter
 114  * @word1:      the first 64 bits of the data
 115  * @word2:      the second 64 bits of the data
 116  */
 117 static int rpavscsi_send_crq(struct ibmvscsi_host_data *hostdata,
 118                              u64 word1, u64 word2)
 119 {
 120         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 121
 122         return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
 123 }
 124
 125 /**
 126  * rpavscsi_task: - Process srps asynchronously
 127  * @data:       ibmvscsi_host_data of host
 128  */
 129 static void rpavscsi_task(void *data)
 130 {
 131         struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
 132         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 133         struct viosrp_crq *crq;
 134         int done = 0;
 135
 136         while (!done) {
 137                 /* Pull all the valid messages off the CRQ */
 138                 while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 139                         ibmvscsi_handle_crq(crq, hostdata);
 140                         crq->valid = 0x00;
 141                 }
 142
 143                 vio_enable_interrupts(vdev);
 144                 if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 145                         vio_disable_interrupts(vdev);
 146                         ibmvscsi_handle_crq(crq, hostdata);
 147                         crq->valid = 0x00;
 148                 } else {
 149                         done = 1;
 150                 }
 151         }
 152 }
 153
 154 static void gather_partition_info(void)
 155 {
 156         struct device_node *rootdn;
 157
 158         const char *ppartition_name;
 159         const unsigned int *p_number_ptr;
 160
 161         /* Retrieve information about this partition */
 162         rootdn = of_find_node_by_path("/");
 163         if (!rootdn) {
 164                 return;
 165         }
 166
 167         ppartition_name = of_get_property(rootdn, "ibm,partition-name", NULL);
 168         if (ppartition_name)
 169                 strncpy(partition_name, ppartition_name,
 170                                 sizeof(partition_name));
 171         p_number_ptr = of_get_property(rootdn, "ibm,partition-no", NULL);
 172         if (p_number_ptr)
 173                 partition_number = *p_number_ptr;
 174         of_node_put(rootdn);
 175 }
 176
 177 static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
 178 {
 179         memset(&hostdata->madapter_info, 0x00,
 180                         sizeof(hostdata->madapter_info));
 181
 182         dev_info(hostdata->dev, "SRP_VERSION: %s\n", SRP_VERSION);
 183         strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);
 184
 185         strncpy(hostdata->madapter_info.partition_name, partition_name,
 186                         sizeof(hostdata->madapter_info.partition_name));
 187
 188         hostdata->madapter_info.partition_number = partition_number;
 189
 190         hostdata->madapter_info.mad_version = 1;
 191         hostdata->madapter_info.os_type = 2;
 192 }
 193
 194 /**
 195  * reset_crq_queue: - resets a crq after a failure
 196  * @queue:      crq_queue to initialize and register
 197  * @hostdata:   ibmvscsi_host_data of host
 198  *
 199  */
 200 static int rpavscsi_reset_crq_queue(struct crq_queue *queue,
 201                                     struct ibmvscsi_host_data *hostdata)
 202 {
 203         int rc;
 204         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 205
 206         /* Close the CRQ */
 207         do {
 208                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 209         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 210
 211         /* Clean out the queue */
 212         memset(queue->msgs, 0x00, PAGE_SIZE);
 213         queue->cur = 0;
 214
 215         set_adapter_info(hostdata);
 216
 217         /* And re-open it again */
 218         rc = plpar_hcall_norets(H_REG_CRQ,
 219                                 vdev->unit_address,
 220                                 queue->msg_token, PAGE_SIZE);
 221         if (rc == 2) {
 222                 /* Adapter is good, but other end is not ready */
 223                 dev_warn(hostdata->dev, "Partner adapter not ready\n");
 224         } else if (rc != 0) {
 225                 dev_warn(hostdata->dev, "couldn't register crq--rc 0x%x\n", rc);
 226         }
 227         return rc;
 228 }
 229
 230 /**
 231  * initialize_crq_queue: - Initializes and registers CRQ with hypervisor
 232  * @queue:      crq_queue to initialize and register
 233  * @hostdata:   ibmvscsi_host_data of host
 234  *
 235  * Allocates a page for messages, maps it for dma, and registers
 236  * the crq with the hypervisor.
 237  * Returns zero on success.
 238  */
 239 static int rpavscsi_init_crq_queue(struct crq_queue *queue,
 240                                    struct ibmvscsi_host_data *hostdata,
 241                                    int max_requests)
 242 {
 243         int rc;
 244         int retrc;
 245         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 246
 247         queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
 248
 249         if (!queue->msgs)
 250                 goto malloc_failed;
 251         queue->size = PAGE_SIZE / sizeof(*queue->msgs);
 252
 253         queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
 254                                           queue->size * sizeof(*queue->msgs),
 255                                           DMA_BIDIRECTIONAL);
 256
 257         if (dma_mapping_error(hostdata->dev, queue->msg_token))
 258                 goto map_failed;
 259
 260         gather_partition_info();
 261         set_adapter_info(hostdata);
 262
 263         retrc = rc = plpar_hcall_norets(H_REG_CRQ,
 264                                 vdev->unit_address,
 265                                 queue->msg_token, PAGE_SIZE);
 266         if (rc == H_RESOURCE)
 267                 /* maybe kexecing and resource is busy. try a reset */
 268                 rc = rpavscsi_reset_crq_queue(queue,
 269                                               hostdata);
 270
 271         if (rc == 2) {
 272                 /* Adapter is good, but other end is not ready */
 273                 dev_warn(hostdata->dev, "Partner adapter not ready\n");
 274                 retrc = 0;
 275         } else if (rc != 0) {
 276                 dev_warn(hostdata->dev, "Error %d opening adapter\n", rc);
 277                 goto reg_crq_failed;
 278         }
 279
 280         queue->cur = 0;
 281         spin_lock_init(&queue->lock);
 282
 283         tasklet_init(&hostdata->srp_task, (void *)rpavscsi_task,
 284                      (unsigned long)hostdata);
 285
 286         if (request_irq(vdev->irq,
 287                         rpavscsi_handle_event,
 288                         0, "ibmvscsi", (void *)hostdata) != 0) {
 289                 dev_err(hostdata->dev, "couldn't register irq 0x%x\n",
 290                         vdev->irq);
 291                 goto req_irq_failed;
 292         }
 293
 294         rc = vio_enable_interrupts(vdev);
 295         if (rc != 0) {
 296                 dev_err(hostdata->dev, "Error %d enabling interrupts!!!\n", rc);
 297                 goto req_irq_failed;
 298         }
 299
 300         return retrc;
 301
 302       req_irq_failed:
 303         tasklet_kill(&hostdata->srp_task);
 304         do {
 305                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 306         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 307       reg_crq_failed:
 308         dma_unmap_single(hostdata->dev,
 309                          queue->msg_token,
 310                          queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
 311       map_failed:
 312         free_page((unsigned long)queue->msgs);
 313       malloc_failed:
 314         return -1;
 315 }
 316
 317 /**
 318  * reenable_crq_queue: - reenables a crq after
 319  * @queue:      crq_queue to initialize and register
 320  * @hostdata:   ibmvscsi_host_data of host
 321  *
 322  */
 323 static int rpavscsi_reenable_crq_queue(struct crq_queue *queue,
 324                                        struct ibmvscsi_host_data *hostdata)
 325 {
 326         int rc;
 327         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 328
 329         /* Re-enable the CRQ */
 330         do {
 331                 rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
 332         } while ((rc == H_IN_PROGRESS) || (rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 333
 334         if (rc)
 335                 dev_err(hostdata->dev, "Error %d enabling adapter\n", rc);
 336         return rc;
 337 }
 338
 339 /**
 340  * rpavscsi_resume: - resume after suspend
 341  * @hostdata:   ibmvscsi_host_data of host
 342  *
 343  */
 344 static int rpavscsi_resume(struct ibmvscsi_host_data *hostdata)
 345 {
 346         vio_disable_interrupts(to_vio_dev(hostdata->dev));
 347         tasklet_schedule(&hostdata->srp_task);
 348         return 0;
 349 }
 350
 351 struct ibmvscsi_ops rpavscsi_ops = {
 352         .init_crq_queue = rpavscsi_init_crq_queue,
 353         .release_crq_queue = rpavscsi_release_crq_queue,
 354         .reset_crq_queue = rpavscsi_reset_crq_queue,
 355         .reenable_crq_queue = rpavscsi_reenable_crq_queue,
 356         .send_crq = rpavscsi_send_crq,
 357         .resume = rpavscsi_resume,
 358 };