ide-{floppy,tape}: remove packet command stack

* Add 'struct ide_atapi_pc queued_pc' to struct ide_{floppy,tape}_obj
  and switch ide*_do_request() to use it (there can be only one active
  request for a given device).

* Add 'struct ide_atapi_pc request_sense_pc' to struct ide_*_obj
  and switch ide*_retry_pc() to use it.

* Remove needless {floppy,tape}->pc assignment from ide*_setup().

* Remove no longer needed ide*_next_pc_storage(), pc_stack[],
  rq_stack_index, IDE*_PC_STACK and DBG_PC_STACK.

There should be no functional changes caused by this patch.

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

diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c
index 41bb610..58cd6e6 100644 (file)
--- a/drivers/ide/ide-floppy.c
+++ b/drivers/ide/ide-floppy.c
@@ -75,13 +75,6 @@
  */
 #define IDEFLOPPY_PC_BUFFER_SIZE       256
 
-/*
- * In various places in the driver, we need to allocate storage for packet
- * commands, which will remain valid while we leave the driver to wait for
- * an interrupt or a timeout event.
- */
-#define IDEFLOPPY_PC_STACK             (10 + IDEFLOPPY_MAX_PC_RETRIES)
-
 /* format capacities descriptor codes */
 #define CAPACITY_INVALID       0x00
 #define CAPACITY_UNFORMATTED   0x01
@@ -104,11 +97,10 @@ typedef struct ide_floppy_obj {
        struct ide_atapi_pc *pc;
        /* Last failed packet command */
        struct ide_atapi_pc *failed_pc;
-       /* Packet command stack */
-       struct ide_atapi_pc pc_stack[IDEFLOPPY_PC_STACK];
-       /* Next free packet command storage space */
-       int pc_stack_index;
+       /* used for blk_{fs,pc}_request() requests */
+       struct ide_atapi_pc queued_pc;
 
+       struct ide_atapi_pc request_sense_pc;
        struct request request_sense_rq;
 
        /* Last error information */
@@ -296,15 +288,6 @@ static void idefloppy_queue_pc_head(ide_drive_t *drive, struct ide_atapi_pc *pc,
        ide_do_drive_cmd(drive, rq);
 }
 
-static struct ide_atapi_pc *idefloppy_next_pc_storage(ide_drive_t *drive)
-{
-       idefloppy_floppy_t *floppy = drive->driver_data;
-
-       if (floppy->pc_stack_index == IDEFLOPPY_PC_STACK)
-               floppy->pc_stack_index = 0;
-       return (&floppy->pc_stack[floppy->pc_stack_index++]);
-}
-
 static void ide_floppy_callback(ide_drive_t *drive)
 {
        idefloppy_floppy_t *floppy = drive->driver_data;
@@ -365,10 +348,9 @@ static void idefloppy_retry_pc(ide_drive_t *drive)
 {
        struct ide_floppy_obj *floppy = drive->driver_data;
        struct request *rq = &floppy->request_sense_rq;
-       struct ide_atapi_pc *pc;
+       struct ide_atapi_pc *pc = &floppy->request_sense_pc;
 
        (void)ide_read_error(drive);
-       pc = idefloppy_next_pc_storage(drive);
        idefloppy_create_request_sense_cmd(pc);
        idefloppy_queue_pc_head(drive, pc, rq);
 }
@@ -629,12 +611,12 @@ static ide_startstop_t idefloppy_do_request(ide_drive_t *drive,
                        idefloppy_end_request(drive, 0, 0);
                        return ide_stopped;
                }
-               pc = idefloppy_next_pc_storage(drive);
+               pc = &floppy->queued_pc;
                idefloppy_create_rw_cmd(floppy, pc, rq, block);
        } else if (blk_special_request(rq)) {
                pc = (struct ide_atapi_pc *) rq->buffer;
        } else if (blk_pc_request(rq)) {
-               pc = idefloppy_next_pc_storage(drive);
+               pc = &floppy->queued_pc;
                idefloppy_blockpc_cmd(floppy, pc, rq);
        } else {
                blk_dump_rq_flags(rq,
@@ -1010,7 +992,7 @@ static void idefloppy_setup(ide_drive_t *drive, idefloppy_floppy_t *floppy)
        u8 gcw[2];
 
        *((u16 *)&gcw) = id[ATA_ID_CONFIG];
-       floppy->pc = floppy->pc_stack;
+
        drive->pc_callback = ide_floppy_callback;
 
        if (((gcw[0] & 0x60) >> 5) == 1)

diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index dd35335..ba05e03 100644 (file)
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -56,8 +56,6 @@ enum {
        DBG_CHRDEV =            (1 << 2),
        /* all remaining procedures */
        DBG_PROCS =             (1 << 3),
-       /* buffer alloc info (pc_stack) */
-       DBG_PC_STACK =  (1 << 4),
 };
 
 /* define to see debug info */
@@ -89,13 +87,6 @@ enum {
 #define IDETAPE_PC_BUFFER_SIZE         256
 
 /*
- * In various places in the driver, we need to allocate storage for packet
- * commands, which will remain valid while we leave the driver to wait for
- * an interrupt or a timeout event.
- */
-#define IDETAPE_PC_STACK               (10 + IDETAPE_MAX_PC_RETRIES)
-
-/*
  * Some drives (for example, Seagate STT3401A Travan) require a very long
  * timeout, because they don't return an interrupt or clear their busy bit
  * until after the command completes (even retension commands).
@@ -208,13 +199,6 @@ typedef struct ide_tape_obj {
        struct kref     kref;
 
        /*
-        *      Since a typical character device operation requires more
-        *      than one packet command, we provide here enough memory
-        *      for the maximum of interconnected packet commands.
-        *      The packet commands are stored in the circular array pc_stack.
-        *      pc_stack_index points to the last used entry, and warps around
-        *      to the start when we get to the last array entry.
-        *
         *      pc points to the current processed packet command.
         *
         *      failed_pc points to the last failed packet command, or contains
@@ -226,11 +210,10 @@ typedef struct ide_tape_obj {
        struct ide_atapi_pc *pc;
        /* Last failed packet command */
        struct ide_atapi_pc *failed_pc;
-       /* Packet command stack */
-       struct ide_atapi_pc pc_stack[IDETAPE_PC_STACK];
-       /* Next free packet command storage space */
-       int pc_stack_index;
+       /* used by REQ_IDETAPE_{READ,WRITE} requests */
+       struct ide_atapi_pc queued_pc;
 
+       struct ide_atapi_pc request_sense_pc;
        struct request request_sense_rq;
 
        /*
@@ -452,23 +435,6 @@ static void idetape_update_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc)
 }
 
 /*
- *     idetape_next_pc_storage returns a pointer to a place in which we can
- *     safely store a packet command, even though we intend to leave the
- *     driver. A storage space for a maximum of IDETAPE_PC_STACK packet
- *     commands is allocated at initialization time.
- */
-static struct ide_atapi_pc *idetape_next_pc_storage(ide_drive_t *drive)
-{
-       idetape_tape_t *tape = drive->driver_data;
-
-       debug_log(DBG_PC_STACK, "pc_stack_index=%d\n", tape->pc_stack_index);
-
-       if (tape->pc_stack_index == IDETAPE_PC_STACK)
-               tape->pc_stack_index = 0;
-       return (&tape->pc_stack[tape->pc_stack_index++]);
-}
-
-/*
  * called on each failed packet command retry to analyze the request sense. We
  * currently do not utilize this information.
  */
@@ -693,10 +659,9 @@ static void idetape_retry_pc(ide_drive_t *drive)
 {
        struct ide_tape_obj *tape = drive->driver_data;
        struct request *rq = &tape->request_sense_rq;
-       struct ide_atapi_pc *pc;
+       struct ide_atapi_pc *pc = &tape->request_sense_pc;
 
        (void)ide_read_error(drive);
-       pc = idetape_next_pc_storage(drive);
        idetape_create_request_sense_cmd(pc);
        set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
        idetape_queue_pc_head(drive, pc, rq);
@@ -1006,12 +971,12 @@ static ide_startstop_t idetape_do_request(ide_drive_t *drive,
                return ide_stopped;
        }
        if (rq->cmd[13] & REQ_IDETAPE_READ) {
-               pc = idetape_next_pc_storage(drive);
+               pc = &tape->queued_pc;
                ide_tape_create_rw_cmd(tape, pc, rq, READ_6);
                goto out;
        }
        if (rq->cmd[13] & REQ_IDETAPE_WRITE) {
-               pc = idetape_next_pc_storage(drive);
+               pc = &tape->queued_pc;
                ide_tape_create_rw_cmd(tape, pc, rq, WRITE_6);
                goto out;
        }
@@ -2412,7 +2377,6 @@ static void idetape_setup(ide_drive_t *drive, idetape_tape_t *tape, int minor)
        tape->name[1] = 't';
        tape->name[2] = '0' + minor;
        tape->chrdev_dir = IDETAPE_DIR_NONE;
-       tape->pc = tape->pc_stack;
 
        *((u16 *)&gcw) = drive->id[ATA_ID_CONFIG];