[ide] sg PIO for taskfile requests

Use scatterlists for taskfile based PIO transfers
instead of directly walking rq->[bio,cbio] lists.

If CONFIG_IDE_TASKFILE_IO is defined
this code will be used for fs requests.

ide_pio_sector() is based on ata_pio_sector()
from libata-core.c so kudos to Jeff.

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

diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 70e93aa031cb7661d82116adf1abf5c5f9285b1c..f35ab894b070c23088c6add8655cf0016756cb1d 100644 (file)
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -516,6 +516,9 @@ static u8 get_command(ide_drive_t *drive, struct request *rq, ide_task_t *task)
                        dma = 0;
        }
 
+       if (!dma)
+               ide_init_sg_cmd(drive, rq);
+
        if (rq_data_dir(rq) == READ) {
                task->command_type = IDE_DRIVE_TASK_IN;
                if (dma)
@@ -779,10 +782,6 @@ ide_startstop_t idedisk_error (ide_drive_t *drive, const char *msg, u8 stat)
                ide_end_drive_cmd(drive, stat, err);
                return ide_stopped;
        }
-#ifdef CONFIG_IDE_TASKFILE_IO
-       /* make rq completion pointers new submission pointers */
-       blk_rq_prep_restart(rq);
-#endif
 
        if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
                /* other bits are useless when BUSY */

diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index d20cd1eb537a985f75db000427b247ec0142e2f1..d0458c79c21f634434f0f8f8f5de9c76bbd37d28 100644 (file)
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -47,6 +47,7 @@
 #include <linux/seq_file.h>
 #include <linux/device.h>
 #include <linux/kmod.h>
+#include <linux/scatterlist.h>
 
 #include <asm/byteorder.h>
 #include <asm/irq.h>
@@ -674,6 +675,31 @@ ide_startstop_t do_special (ide_drive_t *drive)
 
 EXPORT_SYMBOL(do_special);
 
+static void ide_map_sg(ide_drive_t *drive, struct request *rq)
+{
+       ide_hwif_t *hwif = drive->hwif;
+       struct scatterlist *sg = hwif->sg_table;
+
+       if ((rq->flags & REQ_DRIVE_TASKFILE) == 0) {
+               hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
+       } else {
+               sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
+               hwif->sg_nents = 1;
+       }
+}
+
+void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq)
+{
+       ide_hwif_t *hwif = drive->hwif;
+
+       hwif->nsect = hwif->nleft = rq->nr_sectors;
+       hwif->cursg = hwif->cursg_ofs = 0;
+
+       ide_map_sg(drive, rq);
+}
+
+EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
+
 /**
  *     execute_drive_command   -       issue special drive command
  *     @drive: the drive to issue th command on
@@ -697,6 +723,16 @@ ide_startstop_t execute_drive_cmd (ide_drive_t *drive, struct request *rq)
 
                hwif->data_phase = args->data_phase;
 
+               switch (hwif->data_phase) {
+               case TASKFILE_MULTI_OUT:
+               case TASKFILE_OUT:
+               case TASKFILE_MULTI_IN:
+               case TASKFILE_IN:
+                       ide_init_sg_cmd(drive, rq);
+               default:
+                       break;
+               }
+
                if (args->tf_out_flags.all != 0) 
                        return flagged_taskfile(drive, args);
                return do_rw_taskfile(drive, args);

diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index 4a8019475c02684de1eb69bcee245a761062ec6f..9d70e5c9ff05ac450e7cdc35274e844613e14683 100644 (file)
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -5,7 +5,7 @@
  *  Copyright (C) 2000-2002    Andre Hedrick <andre@linux-ide.org>
  *  Copyright (C) 2001-2002    Klaus Smolin
  *                                     IBM Storage Technology Division
- *  Copyright (C) 2003         Bartlomiej Zolnierkiewicz
+ *  Copyright (C) 2003-2004    Bartlomiej Zolnierkiewicz
  *
  *  The big the bad and the ugly.
  *
@@ -253,73 +253,6 @@ ide_startstop_t task_no_data_intr (ide_drive_t *drive)
 
 EXPORT_SYMBOL(task_no_data_intr);
 
-static void task_buffer_sectors(ide_drive_t *drive, struct request *rq,
-                               unsigned nsect, unsigned rw)
-{
-       char *buf = rq->buffer + blk_rq_offset(rq);
-
-       rq->sector += nsect;
-       rq->current_nr_sectors -= nsect;
-       rq->nr_sectors -= nsect;
-       __task_sectors(drive, buf, nsect, rw);
-}
-
-static inline void task_buffer_multi_sectors(ide_drive_t *drive,
-                                            struct request *rq, unsigned rw)
-{
-       unsigned int msect = drive->mult_count, nsect;
-
-       nsect = rq->current_nr_sectors;
-       if (nsect > msect)
-               nsect = msect;
-
-       task_buffer_sectors(drive, rq, nsect, rw);
-}
-
-#ifdef CONFIG_IDE_TASKFILE_IO
-static void task_sectors(ide_drive_t *drive, struct request *rq,
-                        unsigned nsect, unsigned rw)
-{
-       if (rq->cbio) { /* fs request */
-               rq->errors = 0;
-               task_bio_sectors(drive, rq, nsect, rw);
-       } else          /* task request */
-               task_buffer_sectors(drive, rq, nsect, rw);
-}
-
-static inline void task_bio_multi_sectors(ide_drive_t *drive,
-                                         struct request *rq, unsigned rw)
-{
-       unsigned int nsect, msect = drive->mult_count;
-
-       do {
-               nsect = rq->current_nr_sectors;
-               if (nsect > msect)
-                       nsect = msect;
-
-               task_bio_sectors(drive, rq, nsect, rw);
-
-               if (!rq->nr_sectors)
-                       msect = 0;
-               else
-                       msect -= nsect;
-       } while (msect);
-}
-
-static void task_multi_sectors(ide_drive_t *drive,
-                              struct request *rq, unsigned rw)
-{
-       if (rq->cbio) { /* fs request */
-               rq->errors = 0;
-               task_bio_multi_sectors(drive, rq, rw);
-       } else          /* task request */
-               task_buffer_multi_sectors(drive, rq, rw);
-}
-#else
-# define task_sectors(d, rq, nsect, rw)        task_buffer_sectors(d, rq, nsect, rw)
-# define task_multi_sectors(d, rq, rw) task_buffer_multi_sectors(d, rq, rw)
-#endif /* CONFIG_IDE_TASKFILE_IO */
-
 static u8 wait_drive_not_busy(ide_drive_t *drive)
 {
        ide_hwif_t *hwif = HWIF(drive);
@@ -340,16 +273,65 @@ static u8 wait_drive_not_busy(ide_drive_t *drive)
        return stat;
 }
 
+static void ide_pio_sector(ide_drive_t *drive, unsigned int write)
+{
+       ide_hwif_t *hwif = drive->hwif;
+       struct scatterlist *sg = hwif->sg_table;
+       struct page *page;
+#ifdef CONFIG_HIGHMEM
+       unsigned long flags;
+#endif
+       u8 *buf;
+
+       page = sg[hwif->cursg].page;
+#ifdef CONFIG_HIGHMEM
+       local_irq_save(flags);
+#endif
+       buf = kmap_atomic(page, KM_BIO_SRC_IRQ) +
+             sg[hwif->cursg].offset + (hwif->cursg_ofs * SECTOR_SIZE);
+
+       hwif->nleft--;
+       hwif->cursg_ofs++;
+
+       if ((hwif->cursg_ofs * SECTOR_SIZE) == sg[hwif->cursg].length) {
+               hwif->cursg++;
+               hwif->cursg_ofs = 0;
+       }
+
+       /* do the actual data transfer */
+       if (write)
+               taskfile_output_data(drive, buf, SECTOR_WORDS);
+       else
+               taskfile_input_data(drive, buf, SECTOR_WORDS);
+
+       kunmap_atomic(page, KM_BIO_SRC_IRQ);
+#ifdef CONFIG_HIGHMEM
+       local_irq_restore(flags);
+#endif
+}
+
+static void ide_pio_multi(ide_drive_t *drive, unsigned int write)
+{
+       unsigned int nsect;
+
+       nsect = min_t(unsigned int, drive->hwif->nleft, drive->mult_count);
+       while (nsect--)
+               ide_pio_sector(drive, write);
+}
+
 static inline void ide_pio_datablock(ide_drive_t *drive, struct request *rq,
                                     unsigned int write)
 {
+       if (rq->bio)    /* fs request */
+               rq->errors = 0;
+
        switch (drive->hwif->data_phase) {
        case TASKFILE_MULTI_IN:
        case TASKFILE_MULTI_OUT:
-               task_multi_sectors(drive, rq, write);
+               ide_pio_multi(drive, write);
                break;
        default:
-               task_sectors(drive, rq, 1, write);
+               ide_pio_sector(drive, write);
                break;
        }
 }
@@ -359,18 +341,19 @@ static ide_startstop_t task_error(ide_drive_t *drive, struct request *rq,
                                  const char *s, u8 stat)
 {
        if (rq->bio) {
-               int sectors = rq->hard_nr_sectors - rq->nr_sectors;
+               ide_hwif_t *hwif = drive->hwif;
+               int sectors = hwif->nsect - hwif->nleft;
 
-               switch (drive->hwif->data_phase) {
+               switch (hwif->data_phase) {
                case TASKFILE_IN:
-                       if (rq->nr_sectors)
+                       if (hwif->nleft)
                                break;
                        /* fall through */
                case TASKFILE_OUT:
                        sectors--;
                        break;
                case TASKFILE_MULTI_IN:
-                       if (rq->nr_sectors)
+                       if (hwif->nleft)
                                break;
                        /* fall through */
                case TASKFILE_MULTI_OUT:
@@ -407,8 +390,9 @@ static void task_end_request(ide_drive_t *drive, struct request *rq, u8 stat)
  */
 ide_startstop_t task_in_intr (ide_drive_t *drive)
 {
+       ide_hwif_t *hwif = drive->hwif;
        struct request *rq = HWGROUP(drive)->rq;
-       u8 stat = HWIF(drive)->INB(IDE_STATUS_REG);
+       u8 stat = hwif->INB(IDE_STATUS_REG);
 
        if (!OK_STAT(stat, DATA_READY, BAD_R_STAT)) {
                if (stat & (ERR_STAT | DRQ_STAT))
@@ -421,7 +405,7 @@ ide_startstop_t task_in_intr (ide_drive_t *drive)
        ide_pio_datablock(drive, rq, 0);
 
        /* If it was the last datablock check status and finish transfer. */
-       if (!rq->nr_sectors) {
+       if (!hwif->nleft) {
                stat = wait_drive_not_busy(drive);
                if (!OK_STAT(stat, 0, BAD_R_STAT))
                        return task_error(drive, rq, __FUNCTION__, stat);
@@ -441,18 +425,18 @@ EXPORT_SYMBOL(task_in_intr);
  */
 ide_startstop_t task_out_intr (ide_drive_t *drive)
 {
+       ide_hwif_t *hwif = drive->hwif;
        struct request *rq = HWGROUP(drive)->rq;
-       u8 stat;
+       u8 stat = hwif->INB(IDE_STATUS_REG);
 
-       stat = HWIF(drive)->INB(IDE_STATUS_REG);
        if (!OK_STAT(stat, DRIVE_READY, drive->bad_wstat))
                return task_error(drive, rq, __FUNCTION__, stat);
 
        /* Deal with unexpected ATA data phase. */
-       if (((stat & DRQ_STAT) == 0) ^ !rq->nr_sectors)
+       if (((stat & DRQ_STAT) == 0) ^ !hwif->nleft)
                return task_error(drive, rq, __FUNCTION__, stat);
 
-       if (!rq->nr_sectors) {
+       if (!hwif->nleft) {
                task_end_request(drive, rq, stat);
                return ide_stopped;
        }

diff --git a/include/linux/ide.h b/include/linux/ide.h
index 2fddaa5f5f42ec5e66346ba9c20479eca8322d0c..d8b6b870b352280b78b8fb77715131f2a20b41af 100644 (file)
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -927,6 +927,11 @@ typedef struct hwif_s {
        /* data phase of the active command (currently only valid for PIO/DMA) */
        int             data_phase;
 
+       unsigned int nsect;
+       unsigned int nleft;
+       unsigned int cursg;
+       unsigned int cursg_ofs;
+
        int             mmio;           /* hosts iomio (0) or custom (2) select */
        int             rqsize;         /* max sectors per request */
        int             irq;            /* our irq number */
@@ -1370,35 +1375,6 @@ extern void atapi_output_bytes(ide_drive_t *, void *, u32);
 extern void taskfile_input_data(ide_drive_t *, void *, u32);
 extern void taskfile_output_data(ide_drive_t *, void *, u32);
 
-#define IDE_PIO_IN     0
-#define IDE_PIO_OUT    1
-
-static inline void __task_sectors(ide_drive_t *drive, char *buf,
-                                 unsigned nsect, unsigned rw)
-{
-       /*
-        * IRQ can happen instantly after reading/writing
-        * last sector of the datablock.
-        */
-       if (rw == IDE_PIO_OUT)
-               taskfile_output_data(drive, buf, nsect * SECTOR_WORDS);
-       else
-               taskfile_input_data(drive, buf, nsect * SECTOR_WORDS);
-}
-
-#ifdef CONFIG_IDE_TASKFILE_IO
-static inline void task_bio_sectors(ide_drive_t *drive, struct request *rq,
-                                   unsigned nsect, unsigned rw)
-{
-       unsigned long flags;
-       char *buf = rq_map_buffer(rq, &flags);
-
-       process_that_request_first(rq, nsect);
-       __task_sectors(drive, buf, nsect, rw);
-       rq_unmap_buffer(buf, &flags);
-}
-#endif /* CONFIG_IDE_TASKFILE_IO */
-
 extern int drive_is_ready(ide_drive_t *);
 extern int wait_for_ready(ide_drive_t *, int /* timeout */);
 
@@ -1529,6 +1505,8 @@ typedef struct ide_pci_device_s {
 extern void ide_setup_pci_device(struct pci_dev *, ide_pci_device_t *);
 extern void ide_setup_pci_devices(struct pci_dev *, struct pci_dev *, ide_pci_device_t *);
 
+void ide_init_sg_cmd(ide_drive_t *, struct request *);
+
 #define BAD_DMA_DRIVE          0
 #define GOOD_DMA_DRIVE         1