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  * rpavscsi_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 rpavscsi_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 static void rpavscsi_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  * rpavscsi_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 static int rpavscsi_send_crq(struct ibmvscsi_host_data *hostdata,
 117                              u64 word1, u64 word2)
 118 {
 119         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 120
 121         return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
 122 }
 123
 124 /**
 125  * rpavscsi_task: - Process srps asynchronously
 126  * @data:       ibmvscsi_host_data of host
 127  */
 128 static void rpavscsi_task(void *data)
 129 {
 130         struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
 131         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 132         struct viosrp_crq *crq;
 133         int done = 0;
 134
 135         while (!done) {
 136                 /* Pull all the valid messages off the CRQ */
 137                 while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 138                         ibmvscsi_handle_crq(crq, hostdata);
 139                         crq->valid = 0x00;
 140                 }
 141
 142                 vio_enable_interrupts(vdev);
 143                 if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 144                         vio_disable_interrupts(vdev);
 145                         ibmvscsi_handle_crq(crq, hostdata);
 146                         crq->valid = 0x00;
 147                 } else {
 148                         done = 1;
 149                 }
 150         }
 151 }
 152
 153 static void gather_partition_info(void)
 154 {
 155         struct device_node *rootdn;
 156
 157         const char *ppartition_name;
 158         const unsigned int *p_number_ptr;
 159
 160         /* Retrieve information about this partition */
 161         rootdn = of_find_node_by_path("/");
 162         if (!rootdn) {
 163                 return;
 164         }
 165
 166         ppartition_name = of_get_property(rootdn, "ibm,partition-name", NULL);
 167         if (ppartition_name)
 168                 strncpy(partition_name, ppartition_name,
 169                                 sizeof(partition_name));
 170         p_number_ptr = of_get_property(rootdn, "ibm,partition-no", NULL);
 171         if (p_number_ptr)
 172                 partition_number = *p_number_ptr;
 173         of_node_put(rootdn);
 174 }
 175
 176 static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
 177 {
 178         memset(&hostdata->madapter_info, 0x00,
 179                         sizeof(hostdata->madapter_info));
 180
 181         dev_info(hostdata->dev, "SRP_VERSION: %s\n", SRP_VERSION);
 182         strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);
 183
 184         strncpy(hostdata->madapter_info.partition_name, partition_name,
 185                         sizeof(hostdata->madapter_info.partition_name));
 186
 187         hostdata->madapter_info.partition_number = partition_number;
 188
 189         hostdata->madapter_info.mad_version = 1;
 190         hostdata->madapter_info.os_type = 2;
 191 }
 192
 193 /**
 194  * reset_crq_queue: - resets a crq after a failure
 195  * @queue:      crq_queue to initialize and register
 196  * @hostdata:   ibmvscsi_host_data of host
 197  *
 198  */
 199 static int rpavscsi_reset_crq_queue(struct crq_queue *queue,
 200                                     struct ibmvscsi_host_data *hostdata)
 201 {
 202         int rc;
 203         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 204
 205         /* Close the CRQ */
 206         do {
 207                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 208         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 209
 210         /* Clean out the queue */
 211         memset(queue->msgs, 0x00, PAGE_SIZE);
 212         queue->cur = 0;
 213
 214         set_adapter_info(hostdata);
 215
 216         /* And re-open it again */
 217         rc = plpar_hcall_norets(H_REG_CRQ,
 218                                 vdev->unit_address,
 219                                 queue->msg_token, PAGE_SIZE);
 220         if (rc == 2) {
 221                 /* Adapter is good, but other end is not ready */
 222                 dev_warn(hostdata->dev, "Partner adapter not ready\n");
 223         } else if (rc != 0) {
 224                 dev_warn(hostdata->dev, "couldn't register crq--rc 0x%x\n", rc);
 225         }
 226         return rc;
 227 }
 228
 229 /**
 230  * initialize_crq_queue: - Initializes and registers CRQ with hypervisor
 231  * @queue:      crq_queue to initialize and register
 232  * @hostdata:   ibmvscsi_host_data of host
 233  *
 234  * Allocates a page for messages, maps it for dma, and registers
 235  * the crq with the hypervisor.
 236  * Returns zero on success.
 237  */
 238 static int rpavscsi_init_crq_queue(struct crq_queue *queue,
 239                                    struct ibmvscsi_host_data *hostdata,
 240                                    int max_requests)
 241 {
 242         int rc;
 243         int retrc;
 244         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 245
 246         queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
 247
 248         if (!queue->msgs)
 249                 goto malloc_failed;
 250         queue->size = PAGE_SIZE / sizeof(*queue->msgs);
 251
 252         queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
 253                                           queue->size * sizeof(*queue->msgs),
 254                                           DMA_BIDIRECTIONAL);
 255
 256         if (dma_mapping_error(queue->msg_token))
 257                 goto map_failed;
 258
 259         gather_partition_info();
 260         set_adapter_info(hostdata);
 261
 262         retrc = rc = plpar_hcall_norets(H_REG_CRQ,
 263                                 vdev->unit_address,
 264                                 queue->msg_token, PAGE_SIZE);
 265         if (rc == H_RESOURCE)
 266                 /* maybe kexecing and resource is busy. try a reset */
 267                 rc = rpavscsi_reset_crq_queue(queue,
 268                                               hostdata);
 269
 270         if (rc == 2) {
 271                 /* Adapter is good, but other end is not ready */
 272                 dev_warn(hostdata->dev, "Partner adapter not ready\n");
 273                 retrc = 0;
 274         } else if (rc != 0) {
 275                 dev_warn(hostdata->dev, "Error %d opening adapter\n", rc);
 276                 goto reg_crq_failed;
 277         }
 278
 279         if (request_irq(vdev->irq,
 280                         rpavscsi_handle_event,
 281                         0, "ibmvscsi", (void *)hostdata) != 0) {
 282                 dev_err(hostdata->dev, "couldn't register irq 0x%x\n",
 283                         vdev->irq);
 284                 goto req_irq_failed;
 285         }
 286
 287         rc = vio_enable_interrupts(vdev);
 288         if (rc != 0) {
 289                 dev_err(hostdata->dev, "Error %d enabling interrupts!!!\n", rc);
 290                 goto req_irq_failed;
 291         }
 292
 293         queue->cur = 0;
 294         spin_lock_init(&queue->lock);
 295
 296         tasklet_init(&hostdata->srp_task, (void *)rpavscsi_task,
 297                      (unsigned long)hostdata);
 298
 299         return retrc;
 300
 301       req_irq_failed:
 302         do {
 303                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 304         } while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 305       reg_crq_failed:
 306         dma_unmap_single(hostdata->dev,
 307                          queue->msg_token,
 308                          queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
 309       map_failed:
 310         free_page((unsigned long)queue->msgs);
 311       malloc_failed:
 312         return -1;
 313 }
 314
 315 /**
 316  * reenable_crq_queue: - reenables a crq after
 317  * @queue:      crq_queue to initialize and register
 318  * @hostdata:   ibmvscsi_host_data of host
 319  *
 320  */
 321 static int rpavscsi_reenable_crq_queue(struct crq_queue *queue,
 322                                        struct ibmvscsi_host_data *hostdata)
 323 {
 324         int rc;
 325         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 326
 327         /* Re-enable the CRQ */
 328         do {
 329                 rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
 330         } while ((rc == H_IN_PROGRESS) || (rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 331
 332         if (rc)
 333                 dev_err(hostdata->dev, "Error %d enabling adapter\n", rc);
 334         return rc;
 335 }
 336
 337 struct ibmvscsi_ops rpavscsi_ops = {
 338         .init_crq_queue = rpavscsi_init_crq_queue,
 339         .release_crq_queue = rpavscsi_release_crq_queue,
 340         .reset_crq_queue = rpavscsi_reset_crq_queue,
 341         .reenable_crq_queue = rpavscsi_reenable_crq_queue,
 342         .send_crq = rpavscsi_send_crq,
 343 };