Hello.
Mark Lord wrote:
The READ/WRITE LONG commands are theoretically obsolete,
but the majority of drives in existance still implement them.
The WRITE_LONG and WRITE_LONG_ONCE commands are of particular
interest for fault injection testing -- eg. creating "media errors"
at specific locations on a disk.
The fussy bit is that these commands require a non-standard
sector size, usually 520 bytes instead of 512.
Which requires from the drivers to be able to turn off IDE prefetch (and
maybe posting too). I don't see that in this patch (or are you expecting them
to just "snoop' the commands and do it automagically?).
This patch adds support to libata for READ/WRITE LONG commands
issued via SG_IO/ATA_16.
Signed-off-by: Mark Lord <mlord@xxxxxxxxx>
---
--- linux/include/linux/libata.h.orig 2007-03-07 09:20:04.000000000
-0500
+++ linux/include/linux/libata.h 2007-03-12 13:16:29.000000000 -0400
@@ -425,6 +425,7 @@
int dma_dir;
unsigned int pad_len;
+ unsigned int sect_size;
unsigned int nbytes;
unsigned int curbytes;
Tabs are spoilt. :-/
@@ -1171,6 +1172,7 @@
qc->n_elem = 0;
qc->err_mask = 0;
qc->pad_len = 0;
+ qc->sect_size = ATA_SECT_SIZE;
ata_tf_init(qc->dev, &qc->tf);
--- linux/include/linux/ata.h.orig 2007-03-07 09:21:25.000000000 -0500
+++ linux/include/linux/ata.h 2007-03-12 13:15:45.000000000 -0400
@@ -163,6 +163,12 @@
/* READ_LOG_EXT pages */
ATA_LOG_SATA_NCQ = 0x10,
+ /* READ/WRITE LONG (obsolete) */
+ ATA_CMD_READ_LONG = 0x22,
+ ATA_CMD_READ_LONG_ONCE = 0x23,
+ ATA_CMD_WRITE_LONG = 0x32,
+ ATA_CMD_WRITE_LONG_ONCE = 0x33,
+
/* SETFEATURES stuff */
SETFEATURES_XFER = 0x03,
XFER_UDMA_7 = 0x47,
--- linux/drivers/ata/libata-scsi.c.orig 2007-03-07
09:21:13.000000000 -0500
+++ linux/drivers/ata/libata-scsi.c 2007-03-12 13:14:46.000000000 -0400
@@ -2678,6 +2678,18 @@
tf->device = qc->dev->devno ?
tf->device | ATA_DEV1 : tf->device & ~ATA_DEV1;
+ /* READ/WRITE LONG use a non-standard sect_size */
+ qc->sect_size = ATA_SECT_SIZE;
+ switch (tf->command) {
+ case ATA_CMD_READ_LONG:
+ case ATA_CMD_READ_LONG_ONCE:
+ case ATA_CMD_WRITE_LONG:
+ case ATA_CMD_WRITE_LONG_ONCE:
+ if (tf->protocol != ATA_PROT_PIO || tf->nsect != 1)
+ goto invalid_fld;
+ qc->sect_size = scmd->request_bufflen;
+ }
+
/*
* Filter SET_FEATURES - XFER MODE command -- otherwise,
* SET_FEATURES - XFER MODE must be preceded/succeeded
--- linux/drivers/ata/libata-core.c.orig 2007-03-12
11:22:43.000000000 -0400
+++ linux/drivers/ata/libata-core.c 2007-03-12 13:08:28.000000000 -0400
@@ -4032,10 +4032,10 @@
/**
- * ata_pio_sector - Transfer ATA_SECT_SIZE (512 bytes) of data.
+ * ata_pio_sector - Transfer a sector of data.
* @qc: Command on going
*
- * Transfer ATA_SECT_SIZE of data from/to the ATA device.
+ * Transfer qc->sect_size bytes of data from/to the ATA device.
*
* LOCKING:
* Inherited from caller.
@@ -4050,7 +4050,7 @@
unsigned int offset;
unsigned char *buf;
- if (qc->curbytes == qc->nbytes - ATA_SECT_SIZE)
+ if (qc->curbytes == qc->nbytes - qc->sect_size)
ap->hsm_task_state = HSM_ST_LAST;
page = sg[qc->cursg].page;
@@ -4070,17 +4070,17 @@
buf = kmap_atomic(page, KM_IRQ0);
/* do the actual data transfer */
- ap->ops->data_xfer(qc->dev, buf + offset, ATA_SECT_SIZE,
do_write);
+ ap->ops->data_xfer(qc->dev, buf + offset, qc->sect_size,
do_write);
kunmap_atomic(buf, KM_IRQ0);
local_irq_restore(flags);
} else {
buf = page_address(page);
- ap->ops->data_xfer(qc->dev, buf + offset, ATA_SECT_SIZE,
do_write);
+ ap->ops->data_xfer(qc->dev, buf + offset, qc->sect_size,
do_write);
}
- qc->curbytes += ATA_SECT_SIZE;
- qc->cursg_ofs += ATA_SECT_SIZE;
+ qc->curbytes += qc->sect_size;
+ qc->cursg_ofs += qc->sect_size;
if (qc->cursg_ofs == (&sg[qc->cursg])->length) {
qc->cursg++;
Again, ata_data_xfer() doesn't seem capable of performing ECC read/writes
-- the ECC bytes must be transferred in 8-bit mode, AFAIR. ata_data_xfer() can
oinly do that for optionally trailing odd byte. NAK.
MBR, Sergei
-
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