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 #include "srp.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  * ibmvscsi_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  * @regs:       pt_regs with registers
  50  *
  51  * Disables interrupts and schedules srp_task
  52  * Always returns IRQ_HANDLED
  53  */
  54 static irqreturn_t ibmvscsi_handle_event(int irq,
  55                                          void *dev_instance,
  56                                          struct pt_regs *regs)
  57 {
  58         struct ibmvscsi_host_data *hostdata =
  59             (struct ibmvscsi_host_data *)dev_instance;
  60         vio_disable_interrupts(to_vio_dev(hostdata->dev));
  61         tasklet_schedule(&hostdata->srp_task);
  62         return IRQ_HANDLED;
  63 }
  64
  65 /**
  66  * release_crq_queue: - Deallocates data and unregisters CRQ
  67  * @queue:      crq_queue to initialize and register
  68  * @host_data:  ibmvscsi_host_data of host
  69  *
  70  * Frees irq, deallocates a page for messages, unmaps dma, and unregisters
  71  * the crq with the hypervisor.
  72  */
  73 void ibmvscsi_release_crq_queue(struct crq_queue *queue,
  74                                 struct ibmvscsi_host_data *hostdata,
  75                                 int max_requests)
  76 {
  77         long rc;
  78         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
  79         free_irq(vdev->irq, (void *)hostdata);
  80         tasklet_kill(&hostdata->srp_task);
  81         do {
  82                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
  83         } while ((rc == H_Busy) || (H_isLongBusy(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  * ibmvscsi_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 int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata, u64 word1, u64 word2)
 121 {
 122         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 123
 124         return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
 125 }
 126
 127 /**
 128  * ibmvscsi_task: - Process srps asynchronously
 129  * @data:       ibmvscsi_host_data of host
 130  */
 131 static void ibmvscsi_task(void *data)
 132 {
 133         struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
 134         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 135         struct viosrp_crq *crq;
 136         int done = 0;
 137
 138         while (!done) {
 139                 /* Pull all the valid messages off the CRQ */
 140                 while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 141                         ibmvscsi_handle_crq(crq, hostdata);
 142                         crq->valid = 0x00;
 143                 }
 144
 145                 vio_enable_interrupts(vdev);
 146                 if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 147                         vio_disable_interrupts(vdev);
 148                         ibmvscsi_handle_crq(crq, hostdata);
 149                         crq->valid = 0x00;
 150                 } else {
 151                         done = 1;
 152                 }
 153         }
 154 }
 155
 156 static void gather_partition_info(void)
 157 {
 158         struct device_node *rootdn;
 159
 160         char *ppartition_name;
 161         unsigned int *p_number_ptr;
 162
 163         /* Retrieve information about this partition */
 164         rootdn = find_path_device("/");
 165         if (!rootdn) {
 166                 return;
 167         }
 168
 169         ppartition_name =
 170                 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 =
 175                 (unsigned int *)get_property(rootdn, "ibm,partition-no",
 176                                              NULL);
 177         if (p_number_ptr)
 178                 partition_number = *p_number_ptr;
 179 }
 180
 181 static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
 182 {
 183         memset(&hostdata->madapter_info, 0x00,
 184                         sizeof(hostdata->madapter_info));
 185
 186         printk(KERN_INFO "rpa_vscsi: SPR_VERSION: %s\n", SRP_VERSION);
 187         strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);
 188
 189         strncpy(hostdata->madapter_info.partition_name, partition_name,
 190                         sizeof(hostdata->madapter_info.partition_name));
 191
 192         hostdata->madapter_info.partition_number = partition_number;
 193
 194         hostdata->madapter_info.mad_version = 1;
 195         hostdata->madapter_info.os_type = 2;
 196 }
 197
 198 /**
 199  * initialize_crq_queue: - Initializes and registers CRQ with hypervisor
 200  * @queue:      crq_queue to initialize and register
 201  * @hostdata:   ibmvscsi_host_data of host
 202  *
 203  * Allocates a page for messages, maps it for dma, and registers
 204  * the crq with the hypervisor.
 205  * Returns zero on success.
 206  */
 207 int ibmvscsi_init_crq_queue(struct crq_queue *queue,
 208                             struct ibmvscsi_host_data *hostdata,
 209                             int max_requests)
 210 {
 211         int rc;
 212         struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 213
 214         queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);
 215
 216         if (!queue->msgs)
 217                 goto malloc_failed;
 218         queue->size = PAGE_SIZE / sizeof(*queue->msgs);
 219
 220         queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
 221                                           queue->size * sizeof(*queue->msgs),
 222                                           DMA_BIDIRECTIONAL);
 223
 224         if (dma_mapping_error(queue->msg_token))
 225                 goto map_failed;
 226
 227         gather_partition_info();
 228         set_adapter_info(hostdata);
 229
 230         rc = plpar_hcall_norets(H_REG_CRQ,
 231                                 vdev->unit_address,
 232                                 queue->msg_token, PAGE_SIZE);
 233         if (rc == 2) {
 234                 /* Adapter is good, but other end is not ready */
 235                 printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
 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 0;
 263
 264       req_irq_failed:
 265         do {
 266                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 267         } while ((rc == H_Busy) || (H_isLongBusy(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  * reset_crq_queue: - resets a crq after a failure
 280  * @queue:      crq_queue to initialize and register
 281  * @hostdata:   ibmvscsi_host_data of host
 282  *
 283  */
 284 void ibmvscsi_reset_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         /* Close the CRQ */
 291         do {
 292                 rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 293         } while ((rc == H_Busy) || (H_isLongBusy(rc)));
 294
 295         /* Clean out the queue */
 296         memset(queue->msgs, 0x00, PAGE_SIZE);
 297         queue->cur = 0;
 298
 299         set_adapter_info(hostdata);
 300
 301         /* And re-open it again */
 302         rc = plpar_hcall_norets(H_REG_CRQ,
 303                                 vdev->unit_address,
 304                                 queue->msg_token, PAGE_SIZE);
 305         if (rc == 2) {
 306                 /* Adapter is good, but other end is not ready */
 307                 printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
 308         } else if (rc != 0) {
 309                 printk(KERN_WARNING
 310                        "ibmvscsi: couldn't register crq--rc 0x%x\n", rc);
 311         }
 312 }