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author | Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> | 2008-01-26 20:13:09 +0100 |
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committer | Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> | 2008-01-26 20:13:09 +0100 |
commit | 9e47be0c97f7357b80e91dc0632e9cce2eb025e0 (patch) | |
tree | 7047b2b3c9ac094b801d376e4bbb95292b1962ac | |
parent | 3a5015cc9d7051ce8e706ef48276d8484aac0c4b (diff) | |
download | op-kernel-dev-9e47be0c97f7357b80e91dc0632e9cce2eb025e0.zip op-kernel-dev-9e47be0c97f7357b80e91dc0632e9cce2eb025e0.tar.gz |
ide: remove broken disk byte-swapping support
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 ones) 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). ]
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
-rw-r--r-- | Documentation/ide.txt | 4 | ||||
-rw-r--r-- | drivers/ide/ide-disk.c | 1 | ||||
-rw-r--r-- | drivers/ide/ide-taskfile.c | 32 | ||||
-rw-r--r-- | drivers/ide/ide.c | 6 | ||||
-rw-r--r-- | include/linux/ide.h | 1 |
5 files changed, 3 insertions, 41 deletions
diff --git a/Documentation/ide.txt b/Documentation/ide.txt index b29ccb4..94e2e3b 100644 --- a/Documentation/ide.txt +++ b/Documentation/ide.txt @@ -244,10 +244,6 @@ Summary of ide driver parameters for kernel command line "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. diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c index c1fb75c..041be43 100644 --- a/drivers/ide/ide-disk.c +++ b/drivers/ide/ide-disk.c @@ -761,7 +761,6 @@ static void idedisk_add_settings(ide_drive_t *drive) 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); diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c index c58edc8..3ecafab 100644 --- 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 *drive, unsigned int write) /* 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 diff --git a/drivers/ide/ide.c b/drivers/ide/ide.c index 5f3e53e..52115ef 100644 --- a/drivers/ide/ide.c +++ b/drivers/ide/ide.c @@ -1303,7 +1303,7 @@ 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; @@ -1339,10 +1339,6 @@ 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; diff --git a/include/linux/ide.h b/include/linux/ide.h index 74f1ef9..f94cf03 100644 --- 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 */ |