Remove broken disk byte-swapping support: - it can cause a data corruption on SMP (or if using PREEMPT on UP) - all data coming from disk are byte-swapped by taskfile_*_data() which results in incorrect identify data being reported by /proc/ide/ and IOCTLs - "hdx=bswap/byteswap" kernel parameter has been broken on m68k host drivers (including Atari Q40 one) since 2.5.x days (because of 'hwif' zero-ing) - byte-swapping is limited to PIO transfers (for working with TiVo disks on x86 machines using user-space solutions or dm-byteswap should result in much better performance because DMA can be used) For previous discussions please see: http://www.ussg.iu.edu/hypermail/linux/kernel/0201.0/0768.html http://lkml.org/lkml/2004/2/28/111 [ I have dm-byteswap device mapper target if somebody is interested (patch is for 2.6.4 though but I'll dust it off if needed). ] Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx> --- Documentation/ide.txt | 4 ---- drivers/ide/ide-disk.c | 1 - drivers/ide/ide-taskfile.c | 32 ++------------------------------ drivers/ide/ide.c | 6 +----- include/linux/ide.h | 1 - 5 files changed, 3 insertions(+), 41 deletions(-) Index: b/Documentation/ide.txt =================================================================== --- a/Documentation/ide.txt +++ b/Documentation/ide.txt @@ -244,10 +244,6 @@ Summary of ide driver parameters for ker "hdx=nodma" : disallow DMA - "hdx=swapdata" : when the drive is a disk, byte swap all data - - "hdx=bswap" : same as above.......... - "hdx=scsi" : the return of the ide-scsi flag, this is useful for allowing ide-floppy, ide-tape, and ide-cdrom|writers to use ide-scsi emulation on a device specific option. Index: b/drivers/ide/ide-disk.c =================================================================== --- a/drivers/ide/ide-disk.c +++ b/drivers/ide/ide-disk.c @@ -761,7 +761,6 @@ static void idedisk_add_settings(ide_dri ide_add_setting(drive, "bios_head", SETTING_RW, TYPE_BYTE, 0, 255, 1, 1, &drive->bios_head, NULL); ide_add_setting(drive, "bios_sect", SETTING_RW, TYPE_BYTE, 0, 63, 1, 1, &drive->bios_sect, NULL); ide_add_setting(drive, "address", SETTING_RW, TYPE_BYTE, 0, 2, 1, 1, &drive->addressing, set_lba_addressing); - ide_add_setting(drive, "bswap", SETTING_READ, TYPE_BYTE, 0, 1, 1, 1, &drive->bswap, NULL); ide_add_setting(drive, "multcount", SETTING_RW, TYPE_BYTE, 0, id->max_multsect, 1, 1, &drive->mult_count, set_multcount); ide_add_setting(drive, "nowerr", SETTING_RW, TYPE_BYTE, 0, 1, 1, 1, &drive->nowerr, set_nowerr); ide_add_setting(drive, "lun", SETTING_RW, TYPE_INT, 0, 7, 1, 1, &drive->lun, NULL); Index: b/drivers/ide/ide-taskfile.c =================================================================== --- a/drivers/ide/ide-taskfile.c +++ b/drivers/ide/ide-taskfile.c @@ -35,34 +35,6 @@ #include <asm/uaccess.h> #include <asm/io.h> -static void ata_bswap_data (void *buffer, int wcount) -{ - u16 *p = buffer; - - while (wcount--) { - *p = *p << 8 | *p >> 8; p++; - *p = *p << 8 | *p >> 8; p++; - } -} - -static void taskfile_input_data(ide_drive_t *drive, void *buffer, u32 wcount) -{ - HWIF(drive)->ata_input_data(drive, buffer, wcount); - if (drive->bswap) - ata_bswap_data(buffer, wcount); -} - -static void taskfile_output_data(ide_drive_t *drive, void *buffer, u32 wcount) -{ - if (drive->bswap) { - ata_bswap_data(buffer, wcount); - HWIF(drive)->ata_output_data(drive, buffer, wcount); - ata_bswap_data(buffer, wcount); - } else { - HWIF(drive)->ata_output_data(drive, buffer, wcount); - } -} - void ide_tf_load(ide_drive_t *drive, ide_task_t *task) { ide_hwif_t *hwif = drive->hwif; @@ -352,9 +324,9 @@ static void ide_pio_sector(ide_drive_t * /* do the actual data transfer */ if (write) - taskfile_output_data(drive, buf, SECTOR_WORDS); + hwif->ata_output_data(drive, buf, SECTOR_WORDS); else - taskfile_input_data(drive, buf, SECTOR_WORDS); + hwif->ata_input_data(drive, buf, SECTOR_WORDS); kunmap_atomic(buf, KM_BIO_SRC_IRQ); #ifdef CONFIG_HIGHMEM Index: b/drivers/ide/ide.c =================================================================== --- a/drivers/ide/ide.c +++ b/drivers/ide/ide.c @@ -1297,7 +1297,7 @@ static int __init ide_setup(char *s) if (s[0] == 'h' && s[1] == 'd' && s[2] >= 'a' && s[2] <= max_drive) { const char *hd_words[] = { "none", "noprobe", "nowerr", "cdrom", "nodma", - "autotune", "noautotune", "minus8", "swapdata", "bswap", + "autotune", "noautotune", "-8", "-9", "-10", "noflush", "remap", "remap63", "scsi", NULL }; unit = s[2] - 'a'; hw = unit / MAX_DRIVES; @@ -1333,10 +1333,6 @@ static int __init ide_setup(char *s) case -7: /* "noautotune" */ drive->autotune = IDE_TUNE_NOAUTO; goto obsolete_option; - case -9: /* "swapdata" */ - case -10: /* "bswap" */ - drive->bswap = 1; - goto done; case -11: /* noflush */ drive->noflush = 1; goto done; Index: b/include/linux/ide.h =================================================================== --- a/include/linux/ide.h +++ b/include/linux/ide.h @@ -394,7 +394,6 @@ typedef struct ide_drive_s { u8 state; /* retry state */ u8 waiting_for_dma; /* dma currently in progress */ u8 unmask; /* okay to unmask other irqs */ - u8 bswap; /* byte swap data */ u8 noflush; /* don't attempt flushes */ u8 dsc_overlap; /* DSC overlap */ u8 nice1; /* give potential excess bandwidth */ - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
