lkml.org 
[lkml]   [2008]   [Mar]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[PATCH] mass storage : emulation of sat scsi_pass_thru with ATACB
    Hi,

    I have got a cypress usb-ide bridge and I would like to tune or monitor
    my disk with tools like hdparm, hddtemp or smartctl.

    My controller support a way to send raw ATA command to the disk with
    something call atacb (see
    http://download.cypress.com.edgesuite.net/design_resources/datasheets/contents/cy7c68300c_8.pdf).

    Atacb support can be added for each application, but there is some
    disadvantages :
    - all application need to be patched
    - A race is possible if there other accesses, because the emulation can
    be split in 2 atacb scsi transactions. One for sending the command, one
    for reading the register (if ck_cond is set).

    I have implemented the emulation in usb-storage with a special
    proto_handler,
    and an unsual entry.

    Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>

    Index: linux-2.6.24.2/drivers/usb/storage/protocol.c
    ===================================================================
    --- linux-2.6.24.2.orig/drivers/usb/storage/protocol.c 2008-02-29
    22:14:09.000000000 +0100
    +++ linux-2.6.24.2/drivers/usb/storage/protocol.c 2008-03-08
    18:18:22.000000000 +0100
    @@ -47,6 +47,8 @@
    #include <linux/highmem.h>
    #include <scsi/scsi.h>
    #include <scsi/scsi_cmnd.h>
    +#include <scsi/scsi_eh.h>
    +#include <linux/ata.h>

    #include "usb.h"
    #include "protocol.h"
    @@ -144,6 +146,179 @@
    usb_stor_invoke_transport(srb, us);
    }

    +/*
    + * ATACB is a protocol used on cypress usb<->ata bridge to
    + * send raw ATA command over mass storage
    + * There is a ATACB2 protocol that support LBA48 on newer chip.
    + * More info that be found on cy7c68310_8.pdf and cy7c68300c_8.pdf
    + * datasheet from cypress.com.
    + */
    +static void emulate_pass_thru_with_atacb(struct scsi_cmnd *srb,
    + struct us_data *us)
    +{
    + unsigned char save_cmnd[MAX_COMMAND_SIZE];
    + memcpy(save_cmnd, srb->cmnd, sizeof(save_cmnd));
    + memset(srb->cmnd, 0, sizeof(srb->cmnd));
    +
    + /* check if we support the command */
    + if (save_cmnd[1] >> 5) /* MULTIPLE_COUNT */
    + goto invalid_fld;
    + /* check protocol */
    + switch((save_cmnd[1] >> 1) & 0xf) {
    + case 3:
    + case 4:
    + case 5:
    + break;
    + default:
    + goto invalid_fld;
    + }
    +
    + /* first build the ATACB command */
    + srb->cmd_len = 16;
    +
    + /* this value can change, but most(all ?) manufacturers keep the cypress
    + * default : 0x24
    + */
    + srb->cmnd[0] = 0x24;
    + srb->cmnd[1] = 0x24;
    + srb->cmnd[2] = 0;
    +
    + srb->cmnd[3] = 0xff - 1;
    + srb->cmnd[4] = 1;
    +
    + if (save_cmnd[0] == ATA_16) {
    + srb->cmnd[6] = save_cmnd[4]; /* features */
    + srb->cmnd[7] = save_cmnd[6]; /* sector count */
    + srb->cmnd[8] = save_cmnd[8]; /* lba low */
    + srb->cmnd[9] = save_cmnd[10]; /* lba med */
    + srb->cmnd[10] = save_cmnd[12]; /* lba high */
    + srb->cmnd[11] = save_cmnd[13]; /* device */
    + srb->cmnd[12] = save_cmnd[14]; /* command */
    +
    + if (save_cmnd[1] & 0x01) {/* extended bit set for LBA48 */
    + /* this could be supported by atacb2 */
    + if (save_cmnd[3] || save_cmnd[5] || save_cmnd[7] || save_cmnd[9]
    + || save_cmnd[11])
    + goto invalid_fld;
    + }
    + }
    + else { /* ATA12 */
    + srb->cmnd[6] = save_cmnd[3]; /* features */
    + srb->cmnd[7] = save_cmnd[4]; /* sector count */
    + srb->cmnd[8] = save_cmnd[5]; /* lba low */
    + srb->cmnd[9] = save_cmnd[6]; /* lba med */
    + srb->cmnd[10] = save_cmnd[7]; /* lba high */
    + srb->cmnd[11] = save_cmnd[8]; /* device */
    + srb->cmnd[12] = save_cmnd[9]; /* command */
    +
    + }
    + /* Filter SET_FEATURES - XFER MODE command */
    + if ((srb->cmnd[12] == ATA_CMD_SET_FEATURES)
    + && (srb->cmnd[6] == SETFEATURES_XFER))
    + goto invalid_fld;
    +
    + if (srb->cmnd[12] == ATA_CMD_ID_ATA || srb->cmnd[12] == ATA_CMD_ID_ATAPI)
    + srb->cmnd[2] |= (1<<7);
    +
    +
    + usb_stor_invoke_transport(srb, us);
    +
    + /* if the device doesn't support ATACB
    + * abort and register usb_stor_transparent_scsi_command
    + * callback
    + */
    + if (srb->result == SAM_STAT_CHECK_CONDITION &&
    + memcmp(srb->sense_buffer, usb_stor_sense_invalidCDB,
    + sizeof(usb_stor_sense_invalidCDB)) == 0) {
    + us->proto_handler = usb_stor_transparent_scsi_command;
    + goto end;
    + }
    +
    + /* if ck_cond flags is set, and there wasn't critical error,
    + * build the special sense
    + */
    + if ((srb->result != (DID_ERROR << 16) &&
    + srb->result != (DID_ABORT << 16)) &&
    + save_cmnd[2] & 0x20) {
    + struct scsi_eh_save ses;
    + unsigned char sk, asc, ascq;
    + unsigned char regs[8];
    + unsigned char *sb = srb->sense_buffer;
    + unsigned char *desc = sb + 8;
    + int tmp_result;
    +
    + sk = RECOVERED_ERROR;
    + asc = 0; /* ATA PASS THROUGH INFORMATION AVAILABLE */
    + ascq = 0x1D;
    +
    + /* read registers */
    + srb->cmnd[2] = 1;
    + scsi_eh_prep_cmnd(srb, &ses, NULL, 0, 0);
    + srb->request_buffer = regs;
    + srb->request_bufflen = sizeof(regs);
    + srb->sc_data_direction = DMA_FROM_DEVICE;
    +
    + usb_stor_invoke_transport(srb, us);
    + tmp_result = srb->result;
    + scsi_eh_restore_cmnd(srb, &ses);
    + /* we fail to get registers, report invalid command */
    + if (tmp_result != SAM_STAT_GOOD)
    + goto invalid_fld;
    +
    + /* build the sense */
    + memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
    +
    + /* XXX we should generate sk, asc, ascq from status and error
    + * regs
    + * (see 11.1 Error translation ­ ATA device error to SCSI error map)
    + * and ata_to_sense_error from libata.
    + */
    + sb[1] = sk;
    + sb[2] = asc;
    + sb[3] = ascq;
    +
    + /* Sense data is current and format is descriptor. */
    + sb[0] = 0x72;
    + desc[0] = 0x09; /* ATA_RETURN_DESCRIPTOR */
    +
    + /* set length of additional sense data */
    + sb[7] = 14;
    + desc[1] = 12;
    +
    + /* Copy registers into sense buffer. */
    + desc[2] = 0x00;
    + desc[3] = regs[1];
    + desc[5] = regs[2];
    + desc[7] = regs[3];
    + desc[9] = regs[4];
    + desc[11] = regs[5];
    + desc[12] = regs[6];
    + desc[13] = regs[7];
    +
    + srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
    + }
    + goto end;
    +invalid_fld:
    + srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
    +
    + memcpy(srb->sense_buffer,
    + usb_stor_sense_invalidCDB,
    + sizeof(usb_stor_sense_invalidCDB));
    +end:
    + memcpy(srb->cmnd, save_cmnd, sizeof(save_cmnd));
    + if (srb->cmnd[0] == ATA_12)
    + srb->cmd_len = 12;
    +}
    +
    +void usb_stor_transparent_scsi_command_atacb(struct scsi_cmnd *srb,
    + struct us_data *us)
    +{
    + if (srb->cmnd[0] != ATA_16 && srb->cmnd[0] != ATA_12)
    + usb_stor_invoke_transport(srb, us);
    + else
    + emulate_pass_thru_with_atacb(srb, us);
    +}
    +
    /***********************************************************************
    * Scatter-gather transfer buffer access routines
    ***********************************************************************/
    Index: linux-2.6.24.2/drivers/usb/storage/initializers.c
    ===================================================================
    --- linux-2.6.24.2.orig/drivers/usb/storage/initializers.c 2008-02-29
    22:14:09.000000000 +0100
    +++ linux-2.6.24.2/drivers/usb/storage/initializers.c 2008-03-08
    18:30:00.000000000 +0100
    @@ -43,6 +43,7 @@
    #include "initializers.h"
    #include "debug.h"
    #include "transport.h"
    +#include "protocol.h"

    /* This places the Shuttle/SCM USB<->SCSI bridge devices in multi-target
    * mode */
    @@ -104,3 +105,11 @@
    US_DEBUGP("usb_control_msg performing result is %d\n", result);
    return (result ? 0 : -1);
    }
    +
    +/* This function register the atacb proto callback */
    +int usb_atacb_init(struct us_data *us)
    +{
    + us->proto_handler = usb_stor_transparent_scsi_command_atacb;
    + US_DEBUGP("atacb proto_handler is set\n");
    + return 0;
    +}
    Index: linux-2.6.24.2/drivers/usb/storage/initializers.h
    ===================================================================
    --- linux-2.6.24.2.orig/drivers/usb/storage/initializers.h 2008-02-29
    22:14:09.000000000 +0100
    +++ linux-2.6.24.2/drivers/usb/storage/initializers.h 2008-03-08
    18:28:33.000000000 +0100
    @@ -50,3 +50,6 @@

    /* This places the HUAWEI E220 devices in multi-port mode */
    int usb_stor_huawei_e220_init(struct us_data *us);
    +
    +/* This function register the atacb proto callback */
    +int usb_atacb_init(struct us_data *us);
    Index: linux-2.6.24.2/drivers/usb/storage/protocol.h
    ===================================================================
    --- linux-2.6.24.2.orig/drivers/usb/storage/protocol.h 2008-02-29
    22:14:09.000000000 +0100
    +++ linux-2.6.24.2/drivers/usb/storage/protocol.h 2008-02-29
    22:16:03.000000000 +0100
    @@ -47,6 +47,8 @@
    extern void usb_stor_ufi_command(struct scsi_cmnd*, struct us_data*);
    extern void usb_stor_transparent_scsi_command(struct scsi_cmnd*,
    struct us_data*);
    +extern void usb_stor_transparent_scsi_command_atacb(struct scsi_cmnd*,
    + struct us_data*);

    /* struct scsi_cmnd transfer buffer access utilities */
    enum xfer_buf_dir {TO_XFER_BUF, FROM_XFER_BUF};
    Index: linux-2.6.24.2/drivers/usb/storage/unusual_devs.h
    ===================================================================
    --- linux-2.6.24.2.orig/drivers/usb/storage/unusual_devs.h 2008-02-29
    22:14:09.000000000 +0100
    +++ linux-2.6.24.2/drivers/usb/storage/unusual_devs.h 2008-02-29
    22:16:03.000000000 +0100
    @@ -1588,6 +1588,12 @@
    US_SC_DEVICE, US_PR_DEVICE, NULL,
    US_FL_CAPACITY_HEURISTICS),

    +UNUSUAL_DEV( 0x04b4, 0x6830, 0x0000, 0x9999,
    + "Cypress",
    + "Cypress AT2LP",
    + US_SC_SCSI, US_PR_BULK, usb_atacb_init,
    + US_FL_NEED_OVERRIDE),
    +
    /* Control/Bulk transport for all SubClass values */
    USUAL_DEV(US_SC_RBC, US_PR_CB, USB_US_TYPE_STOR),
    USUAL_DEV(US_SC_8020, US_PR_CB, USB_US_TYPE_STOR),
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/
    \
     
     \ /
      Last update: 2008-03-08 18:35    [W:0.051 / U:0.572 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site