[SCSI] drivers/scsi: Use ARRAY_SIZE macro
[linux-2.6-block.git] / drivers / scsi / scsi_lib.c
index 3042520c413cc83a46ca038fe1e4f9b39f1122c9..3ca7b9d3086c0d4de4c49ec4137db2b954ad0730 100644 (file)
@@ -30,7 +30,7 @@
 #include "scsi_logging.h"
 
 
-#define SG_MEMPOOL_NR          (sizeof(scsi_sg_pools)/sizeof(struct scsi_host_sg_pool))
+#define SG_MEMPOOL_NR          ARRAY_SIZE(scsi_sg_pools)
 #define SG_MEMPOOL_SIZE                32
 
 struct scsi_host_sg_pool {
@@ -1479,6 +1479,8 @@ static inline int scsi_host_queue_ready(struct request_queue *q,
 static void scsi_kill_request(struct request *req, request_queue_t *q)
 {
        struct scsi_cmnd *cmd = req->special;
+       struct scsi_device *sdev = cmd->device;
+       struct Scsi_Host *shost = sdev->host;
 
        blkdev_dequeue_request(req);
 
@@ -1491,13 +1493,26 @@ static void scsi_kill_request(struct request *req, request_queue_t *q)
        scsi_init_cmd_errh(cmd);
        cmd->result = DID_NO_CONNECT << 16;
        atomic_inc(&cmd->device->iorequest_cnt);
+
+       /*
+        * SCSI request completion path will do scsi_device_unbusy(),
+        * bump busy counts.  To bump the counters, we need to dance
+        * with the locks as normal issue path does.
+        */
+       sdev->device_busy++;
+       spin_unlock(sdev->request_queue->queue_lock);
+       spin_lock(shost->host_lock);
+       shost->host_busy++;
+       spin_unlock(shost->host_lock);
+       spin_lock(sdev->request_queue->queue_lock);
+
        __scsi_done(cmd);
 }
 
 static void scsi_softirq_done(struct request *rq)
 {
        struct scsi_cmnd *cmd = rq->completion_data;
-       unsigned long wait_for = cmd->allowed * cmd->timeout_per_command;
+       unsigned long wait_for = (cmd->allowed + 1) * cmd->timeout_per_command;
        int disposition;
 
        INIT_LIST_HEAD(&cmd->eh_entry);
@@ -1787,9 +1802,8 @@ int __init scsi_init_queue(void)
                                        sgp->name);
                }
 
-               sgp->pool = mempool_create(SG_MEMPOOL_SIZE,
-                               mempool_alloc_slab, mempool_free_slab,
-                               sgp->slab);
+               sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE,
+                                                    sgp->slab);
                if (!sgp->pool) {
                        printk(KERN_ERR "SCSI: can't init sg mempool %s\n",
                                        sgp->name);
@@ -1811,6 +1825,84 @@ void scsi_exit_queue(void)
                kmem_cache_destroy(sgp->slab);
        }
 }
+
+/**
+ *     scsi_mode_select - issue a mode select
+ *     @sdev:  SCSI device to be queried
+ *     @pf:    Page format bit (1 == standard, 0 == vendor specific)
+ *     @sp:    Save page bit (0 == don't save, 1 == save)
+ *     @modepage: mode page being requested
+ *     @buffer: request buffer (may not be smaller than eight bytes)
+ *     @len:   length of request buffer.
+ *     @timeout: command timeout
+ *     @retries: number of retries before failing
+ *     @data: returns a structure abstracting the mode header data
+ *     @sense: place to put sense data (or NULL if no sense to be collected).
+ *             must be SCSI_SENSE_BUFFERSIZE big.
+ *
+ *     Returns zero if successful; negative error number or scsi
+ *     status on error
+ *
+ */
+int
+scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage,
+                unsigned char *buffer, int len, int timeout, int retries,
+                struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
+{
+       unsigned char cmd[10];
+       unsigned char *real_buffer;
+       int ret;
+
+       memset(cmd, 0, sizeof(cmd));
+       cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0);
+
+       if (sdev->use_10_for_ms) {
+               if (len > 65535)
+                       return -EINVAL;
+               real_buffer = kmalloc(8 + len, GFP_KERNEL);
+               if (!real_buffer)
+                       return -ENOMEM;
+               memcpy(real_buffer + 8, buffer, len);
+               len += 8;
+               real_buffer[0] = 0;
+               real_buffer[1] = 0;
+               real_buffer[2] = data->medium_type;
+               real_buffer[3] = data->device_specific;
+               real_buffer[4] = data->longlba ? 0x01 : 0;
+               real_buffer[5] = 0;
+               real_buffer[6] = data->block_descriptor_length >> 8;
+               real_buffer[7] = data->block_descriptor_length;
+
+               cmd[0] = MODE_SELECT_10;
+               cmd[7] = len >> 8;
+               cmd[8] = len;
+       } else {
+               if (len > 255 || data->block_descriptor_length > 255 ||
+                   data->longlba)
+                       return -EINVAL;
+
+               real_buffer = kmalloc(4 + len, GFP_KERNEL);
+               if (!real_buffer)
+                       return -ENOMEM;
+               memcpy(real_buffer + 4, buffer, len);
+               len += 4;
+               real_buffer[0] = 0;
+               real_buffer[1] = data->medium_type;
+               real_buffer[2] = data->device_specific;
+               real_buffer[3] = data->block_descriptor_length;
+               
+
+               cmd[0] = MODE_SELECT;
+               cmd[4] = len;
+       }
+
+       ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len,
+                              sshdr, timeout, retries);
+       kfree(real_buffer);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(scsi_mode_select);
+
 /**
  *     scsi_mode_sense - issue a mode sense, falling back from 10 to 
  *             six bytes if necessary.
@@ -1832,7 +1924,8 @@ void scsi_exit_queue(void)
 int
 scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
                  unsigned char *buffer, int len, int timeout, int retries,
-                 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) {
+                 struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
+{
        unsigned char cmd[12];
        int use_10_for_ms;
        int header_length;
@@ -2257,3 +2350,61 @@ scsi_target_unblock(struct device *dev)
                device_for_each_child(dev, NULL, target_unblock);
 }
 EXPORT_SYMBOL_GPL(scsi_target_unblock);
+
+/**
+ * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
+ * @sg:                scatter-gather list
+ * @sg_count:  number of segments in sg
+ * @offset:    offset in bytes into sg, on return offset into the mapped area
+ * @len:       bytes to map, on return number of bytes mapped
+ *
+ * Returns virtual address of the start of the mapped page
+ */
+void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
+                         size_t *offset, size_t *len)
+{
+       int i;
+       size_t sg_len = 0, len_complete = 0;
+       struct page *page;
+
+       for (i = 0; i < sg_count; i++) {
+               len_complete = sg_len; /* Complete sg-entries */
+               sg_len += sg[i].length;
+               if (sg_len > *offset)
+                       break;
+       }
+
+       if (unlikely(i == sg_count)) {
+               printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
+                       "elements %d\n",
+                      __FUNCTION__, sg_len, *offset, sg_count);
+               WARN_ON(1);
+               return NULL;
+       }
+
+       /* Offset starting from the beginning of first page in this sg-entry */
+       *offset = *offset - len_complete + sg[i].offset;
+
+       /* Assumption: contiguous pages can be accessed as "page + i" */
+       page = nth_page(sg[i].page, (*offset >> PAGE_SHIFT));
+       *offset &= ~PAGE_MASK;
+
+       /* Bytes in this sg-entry from *offset to the end of the page */
+       sg_len = PAGE_SIZE - *offset;
+       if (*len > sg_len)
+               *len = sg_len;
+
+       return kmap_atomic(page, KM_BIO_SRC_IRQ);
+}
+EXPORT_SYMBOL(scsi_kmap_atomic_sg);
+
+/**
+ * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously
+ *                        mapped with scsi_kmap_atomic_sg
+ * @virt:      virtual address to be unmapped
+ */
+void scsi_kunmap_atomic_sg(void *virt)
+{
+       kunmap_atomic(virt, KM_BIO_SRC_IRQ);
+}
+EXPORT_SYMBOL(scsi_kunmap_atomic_sg);