ide-tape: remove pipeline-specific members from struct ide_tape_obj

Bart:
- merge "ide-tape: remove pipeline-specific code from idetape_setup" patch
- cleanup __idetape_discard_read_pipeline()
- cleanup idetape_empty_write_pipeline()
- fix 't' assignment in idetape_setup()
- fix idetape_blkdev_ioctl() w.r.t. 'nr_stages'

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 14 insertions, 156 deletions

diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index c4b470999203..a81644b2473e 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -324,12 +324,8 @@ typedef struct ide_tape_obj {
          * At most, there is only one ide-tape originated data transfer request
          * in the device request queue. This allows ide.c to easily service
          * requests from the other device when we postpone our active request.
-         * In the pipelined operation mode, we use our internal pipeline
-         * structure to hold more data requests. The data buffer size is chosen
-         * based on the tape's recommendation.
          */
-        /* ptr to the request which is waiting in the device request queue */
-        struct request *active_data_rq;
+
         /* Data buffer size chosen based on the tape's recommendation */
         int stage_size;
         idetape_stage_t *merge_stage;
@@ -338,26 +334,7 @@ typedef struct ide_tape_obj {
         char *b_data;
         int b_count;
 
-        /*
-         * Pipeline parameters.
-         *
-         * To accomplish non-pipelined mode, we simply set the following
-         * variables to zero (or NULL, where appropriate).
-         */
-        /* Number of currently used stages */
-        int nr_stages;
-        /* Number of pending stages */
-        int nr_pending_stages;
-        /* We will not allocate more than this number of stages */
-        int max_stages, min_pipeline, max_pipeline;
-        /* The first stage which will be removed from the pipeline */
-        idetape_stage_t *first_stage;
-        /* The currently active stage */
-        idetape_stage_t *active_stage;
-        /* Will be serviced after the currently active request */
-        idetape_stage_t *next_stage;
-        /* New requests will be added to the pipeline here */
-        idetape_stage_t *last_stage;
+        /* Pipeline parameters. */
         int pages_per_stage;
         /* Wasted space in each stage */
         int excess_bh_size;
@@ -379,18 +356,6 @@ typedef struct ide_tape_obj {
         /* the tape is write protected (hardware or opened as read-only) */
         char write_prot;
 
-        /*
-         * Limit the number of times a request can be postponed, to avoid an
-         * infinite postpone deadlock.
-         */
-        int postpone_cnt;
-
-        /* Speed control at the tape buffers input/output */
-        unsigned long insert_time;
-        int insert_size;
-        int insert_speed;
-        int measure_insert_time;
-
         u32 debug_mask;
 } idetape_tape_t;
 
@@ -1193,17 +1158,7 @@ static ide_startstop_t idetape_rw_callback(ide_drive_t *drive)
         int blocks = tape->pc->xferred / tape->blk_size;
 
         tape->avg_size += blocks * tape->blk_size;
-        tape->insert_size += blocks * tape->blk_size;
-        if (tape->insert_size > 1024 * 1024)
-                tape->measure_insert_time = 1;
-        if (tape->measure_insert_time) {
-                tape->measure_insert_time = 0;
-                tape->insert_time = jiffies;
-                tape->insert_size = 0;
-        }
-        if (time_after(jiffies, tape->insert_time))
-                tape->insert_speed = tape->insert_size / 1024 * HZ /
-                                        (jiffies - tape->insert_time);
+
         if (time_after_eq(jiffies, tape->avg_time + HZ)) {
                 tape->avg_speed = tape->avg_size * HZ /
                                 (jiffies - tape->avg_time) / 1024;
@@ -1308,9 +1263,6 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
                 drive->post_reset = 0;
         }
 
-        if (time_after(jiffies, tape->insert_time))
-                tape->insert_speed = tape->insert_size / 1024 * HZ /
-                                        (jiffies - tape->insert_time);
         if (!test_and_clear_bit(IDETAPE_FLAG_IGNORE_DSC, &tape->flags) &&
             (stat & SEEK_STAT) == 0) {
                 if (postponed_rq == NULL) {
@@ -1334,14 +1286,12 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
                 return ide_stopped;
         }
         if (rq->cmd[0] & REQ_IDETAPE_READ) {
-                tape->postpone_cnt = 0;
                 pc = idetape_next_pc_storage(drive);
                 idetape_create_read_cmd(tape, pc, rq->current_nr_sectors,
                                         (struct idetape_bh *)rq->special);
                 goto out;
         }
         if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
-                tape->postpone_cnt = 0;
                 pc = idetape_next_pc_storage(drive);
                 idetape_create_write_cmd(tape, pc, rq->current_nr_sectors,
                                          (struct idetape_bh *)rq->special);
@@ -1707,16 +1657,11 @@ static int idetape_create_prevent_cmd(ide_drive_t *drive,
 static int __idetape_discard_read_pipeline(ide_drive_t *drive)
 {
         idetape_tape_t *tape = drive->driver_data;
-        unsigned long flags;
-        int cnt;
 
         if (tape->chrdev_dir != IDETAPE_DIR_READ)
                 return 0;
 
-        /* Remove merge stage. */
-        cnt = tape->merge_stage_size / tape->blk_size;
-        if (test_and_clear_bit(IDETAPE_FLAG_FILEMARK, &tape->flags))
-                ++cnt;          /* Filemarks count as 1 sector */
+        clear_bit(IDETAPE_FLAG_FILEMARK, &tape->flags);
         tape->merge_stage_size = 0;
         if (tape->merge_stage != NULL) {
                 __idetape_kfree_stage(tape->merge_stage);
@@ -1725,24 +1670,7 @@ static int __idetape_discard_read_pipeline(ide_drive_t *drive)
 
         tape->chrdev_dir = IDETAPE_DIR_NONE;
 
-        /* Remove pipeline stages. */
-        if (tape->first_stage == NULL)
-                return 0;
-
-        spin_lock_irqsave(&tape->lock, flags);
-        tape->next_stage = NULL;
-        spin_unlock_irqrestore(&tape->lock, flags);
-
-        while (tape->first_stage != NULL) {
-                struct request *rq_ptr = &tape->first_stage->rq;
-
-                cnt += rq_ptr->nr_sectors - rq_ptr->current_nr_sectors;
-                if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
-                        ++cnt;
-        }
-        tape->nr_pending_stages = 0;
-        tape->max_stages = tape->min_pipeline;
-        return cnt;
+        return 0;
 }
 
 /*
@@ -1919,27 +1847,9 @@ static void idetape_empty_write_pipeline(ide_drive_t *drive)
                 tape->merge_stage = NULL;
         }
         tape->chrdev_dir = IDETAPE_DIR_NONE;
-
-        /*
-         * On the next backup, perform the feedback loop again. (I don't want to
-         * keep sense information between backups, as some systems are
-         * constantly on, and the system load can be totally different on the
-         * next backup).
-         */
-        tape->max_stages = tape->min_pipeline;
-        if (tape->first_stage != NULL ||
-            tape->next_stage != NULL ||
-            tape->last_stage != NULL ||
-            tape->nr_stages != 0) {
-                printk(KERN_ERR "ide-tape: ide-tape pipeline bug, "
-                        "first_stage %p, next_stage %p, "
-                        "last_stage %p, nr_stages %d\n",
-                        tape->first_stage, tape->next_stage,
-                        tape->last_stage, tape->nr_stages);
-        }
 }
 
-static int idetape_init_read(ide_drive_t *drive, int max_stages)
+static int idetape_init_read(ide_drive_t *drive)
 {
         idetape_tape_t *tape = drive->driver_data;
         int bytes_read;
@@ -1979,13 +1889,6 @@ static int idetape_init_read(ide_drive_t *drive, int max_stages)
                 }
         }
 
-        if (tape->nr_pending_stages >= 3 * max_stages / 4) {
-                tape->measure_insert_time = 1;
-                tape->insert_time = jiffies;
-                tape->insert_size = 0;
-                tape->insert_speed = 0;
-        }
-
         return 0;
 }
 
@@ -2003,7 +1906,7 @@ static int idetape_add_chrdev_read_request(ide_drive_t *drive, int blocks)
         if (test_bit(IDETAPE_FLAG_FILEMARK, &tape->flags))
                 return 0;
 
-        idetape_init_read(drive, tape->max_stages);
+        idetape_init_read(drive);
 
         return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks,
                                      tape->merge_stage->bh);
@@ -2079,11 +1982,10 @@ static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd,
                 if (copy_from_user(&config, argp, sizeof(config)))
                         return -EFAULT;
                 tape->best_dsc_rw_freq = config.dsc_rw_frequency;
-                tape->max_stages = config.nr_stages;
                 break;
         case 0x0350:
                 config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
-                config.nr_stages = tape->max_stages;
+                config.nr_stages = 1;
                 if (copy_to_user(argp, &config, sizeof(config)))
                         return -EFAULT;
                 break;
@@ -2175,7 +2077,7 @@ static ssize_t idetape_chrdev_read(struct file *file, char __user *buf,
                             (count % tape->blk_size) == 0)
                                 tape->user_bs_factor = count / tape->blk_size;
         }
-        rc = idetape_init_read(drive, tape->max_stages);
+        rc = idetape_init_read(drive);
         if (rc < 0)
                 return rc;
         if (count == 0)
@@ -2793,18 +2695,6 @@ static void idetape_add_settings(ide_drive_t *drive)
 
         ide_add_setting(drive, "buffer", SETTING_READ, TYPE_SHORT, 0, 0xffff,
                         1, 2, (u16 *)&tape->caps[16], NULL);
-        ide_add_setting(drive, "pipeline_min", SETTING_RW, TYPE_INT, 1, 0xffff,
-                        tape->stage_size / 1024, 1, &tape->min_pipeline, NULL);
-        ide_add_setting(drive, "pipeline", SETTING_RW, TYPE_INT, 1, 0xffff,
-                        tape->stage_size / 1024, 1, &tape->max_stages, NULL);
-        ide_add_setting(drive, "pipeline_max", SETTING_RW, TYPE_INT, 1, 0xffff,
-                        tape->stage_size / 1024, 1, &tape->max_pipeline, NULL);
-        ide_add_setting(drive, "pipeline_used", SETTING_READ, TYPE_INT, 0,
-                        0xffff, tape->stage_size / 1024, 1, &tape->nr_stages,
-                        NULL);
-        ide_add_setting(drive, "pipeline_pending", SETTING_READ, TYPE_INT, 0,
-                        0xffff, tape->stage_size / 1024, 1,
-                        &tape->nr_pending_stages, NULL);
         ide_add_setting(drive, "speed", SETTING_READ, TYPE_SHORT, 0, 0xffff,
                         1, 1, (u16 *)&tape->caps[14], NULL);
         ide_add_setting(drive, "stage", SETTING_READ, TYPE_INT, 0, 0xffff, 1,
@@ -2836,11 +2726,10 @@ static inline void idetape_add_settings(ide_drive_t *drive) { ; }
  */
 static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
 {
-        unsigned long t1, tmid, tn, t;
+        unsigned long t;
         int speed;
         int stage_size;
         u8 gcw[2];
-        struct sysinfo si;
         u16 *ctl = (u16 *)&tape->caps[12];
 
         spin_lock_init(&tape->lock);
@@ -2865,10 +2754,6 @@ static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
         if (((gcw[0] & 0x60) >> 5) == 1)
                 set_bit(IDETAPE_FLAG_DRQ_INTERRUPT, &tape->flags);
 
-        tape->min_pipeline = 10;
-        tape->max_pipeline = 10;
-        tape->max_stages   = 10;
-
         idetape_get_inquiry_results(drive);
         idetape_get_mode_sense_results(drive);
         ide_tape_get_bsize_from_bdesc(drive);
@@ -2886,36 +2771,10 @@ static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
                 tape->excess_bh_size = PAGE_SIZE - stage_size % PAGE_SIZE;
         }
 
-        /* Select the "best" DSC read/write polling freq and pipeline size. */
+        /* select the "best" DSC read/write polling freq */
         speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
 
-        tape->max_stages = speed * 1000 * 10 / tape->stage_size;
-
-        /* Limit memory use for pipeline to 10% of physical memory */
-        si_meminfo(&si);
-        if (tape->max_stages * tape->stage_size >
-                        si.totalram * si.mem_unit / 10)
-                tape->max_stages =
-                        si.totalram * si.mem_unit / (10 * tape->stage_size);
-
-        tape->max_stages   = min(tape->max_stages, IDETAPE_MAX_PIPELINE_STAGES);
-        tape->min_pipeline = min(tape->max_stages, IDETAPE_MIN_PIPELINE_STAGES);
-        tape->max_pipeline =
-                min(tape->max_stages * 2, IDETAPE_MAX_PIPELINE_STAGES);
-        if (tape->max_stages == 0) {
-                tape->max_stages   = 1;
-                tape->min_pipeline = 1;
-                tape->max_pipeline = 1;
-        }
-
-        t1 = (tape->stage_size * HZ) / (speed * 1000);
-        tmid = (*(u16 *)&tape->caps[16] * 32 * HZ) / (speed * 125);
-        tn = (IDETAPE_FIFO_THRESHOLD * tape->stage_size * HZ) / (speed * 1000);
-
-        if (tape->max_stages)
-                t = tn;
-        else
-                t = t1;
+        t = (IDETAPE_FIFO_THRESHOLD * tape->stage_size * HZ) / (speed * 1000);
 
         /*
          * Ensure that the number we got makes sense; limit it within
@@ -2925,11 +2784,10 @@ static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
                                 min_t(unsigned long, t, IDETAPE_DSC_RW_MAX),
                                 IDETAPE_DSC_RW_MIN);
         printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
-                "%dkB pipeline, %lums tDSC%s\n",
+                "%lums tDSC%s\n",
                 drive->name, tape->name, *(u16 *)&tape->caps[14],
                 (*(u16 *)&tape->caps[16] * 512) / tape->stage_size,
                 tape->stage_size / 1024,
-                tape->max_stages * tape->stage_size / 1024,
                 tape->best_dsc_rw_freq * 1000 / HZ,
                 drive->using_dma ? ", DMA":"");
 
@@ -2953,7 +2811,7 @@ static void ide_tape_release(struct kref *kref)
         ide_drive_t *drive = tape->drive;
         struct gendisk *g = tape->disk;
 
-        BUG_ON(tape->first_stage != NULL || tape->merge_stage_size);
+        BUG_ON(tape->merge_stage_size);
 
         drive->dsc_overlap = 0;
         drive->driver_data = NULL;