Re: [PATCH v6 4/7] ata: libata: cleanup fua support detection

Niklas Cassel
2022-12-30T08:01:56Z

On Tue, Nov 08, 2022 at 02:55:41PM +0900, Damien Le Moal wrote:
> Move the detection of a device FUA support from
> ata_scsiop_mode_sense()/ata_dev_supports_fua() to device scan time in
> ata_dev_configure().
>
> The function ata_dev_config_fua() is introduced to detect if a device
> supports FUA and this support is indicated using the new device flag
> ATA_DFLAG_FUA.
>
> In order to blacklist known buggy devices, the horkage flag
> ATA_HORKAGE_NO_FUA is introduced. Similarly to other horkage flags, the
> libata.force= arguments "fua" and "nofua" are also introduced to allow
> a user to control this horkage flag through the "force" libata
> module parameter.
>
> The ATA_DFLAG_FUA device flag is set only and only if all the following
> conditions are met:
> * libata.fua module parameter is set to 1
> * The device supports the WRITE DMA FUA EXT command,
> * The device is not marked with the ATA_HORKAGE_NO_FUA flag, either from
> the blacklist or set by the user with libata.force=nofua
> * The device supports NCQ (while this is not mandated by the standards,
> this restriction is introduced to avoid problems with older non-NCQ
> devices).
>
> Enabling or diabling libata FUA support for all devices can now also be
> done using the "force=[no]fua" module parameter when libata.fua is set
> to 1.
>
> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> ---
> .../admin-guide/kernel-parameters.txt | 3 ++
> drivers/ata/libata-core.c | 30 ++++++++++++++++++-
> drivers/ata/libata-scsi.c | 30 ++-----------------
> include/linux/libata.h | 8 +++--
> 4 files changed, 39 insertions(+), 32 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index a465d5242774..f9724642c703 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -2786,6 +2786,9 @@
> * [no]setxfer: Indicate if transfer speed mode setting
> should be skipped.
>
> + * [no]fua: Disable or enable FUA (Force Unit Access)
> + support for devices supporting this feature.
> +
> * dump_id: Dump IDENTIFY data.
>
> * disable: Disable this device.
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index 6ee1cbac3ab0..30adae16efff 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -2422,6 +2422,28 @@ static void ata_dev_config_chs(struct ata_device *dev)
> dev->heads, dev->sectors);
> }
>
> +static void ata_dev_config_fua(struct ata_device *dev)
> +{
> + /* Ignore FUA support if its use is disabled globally */
> + if (!libata_fua)
> + goto nofua;
> +
> + /* Ignore devices without support for WRITE DMA FUA EXT */
> + if (!(dev->flags & ATA_DFLAG_LBA48) || !ata_id_has_fua(dev->id))
> + goto nofua;
> +
> + /* Ignore known bad devices and devices that lack NCQ support */
> + if (!ata_ncq_supported(dev) || (dev->horkage & ATA_HORKAGE_NO_FUA))
> + goto nofua;
> +
> + dev->flags |= ATA_DFLAG_FUA;
> +
> + return;
> +
> +nofua:
> + dev->flags &= ~ATA_DFLAG_FUA;
> +}
> +
> static void ata_dev_config_devslp(struct ata_device *dev)
> {
> u8 *sata_setting = dev->link->ap->sector_buf;
> @@ -2510,7 +2532,8 @@ static void ata_dev_print_features(struct ata_device *dev)
> return;
>
> ata_dev_info(dev,
> - "Features:%s%s%s%s%s%s\n",
> + "Features:%s%s%s%s%s%s%s\n",
> + dev->flags & ATA_DFLAG_FUA ? " FUA" : "",
> dev->flags & ATA_DFLAG_TRUSTED ? " Trust" : "",
> dev->flags & ATA_DFLAG_DA ? " Dev-Attention" : "",
> dev->flags & ATA_DFLAG_DEVSLP ? " Dev-Sleep" : "",
> @@ -2671,6 +2694,7 @@ int ata_dev_configure(struct ata_device *dev)
> ata_dev_config_chs(dev);
> }
>
> + ata_dev_config_fua(dev);
> ata_dev_config_devslp(dev);
> ata_dev_config_sense_reporting(dev);
> ata_dev_config_zac(dev);
> @@ -4105,6 +4129,9 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = {
> */
> { "SATADOM-ML 3ME", NULL, ATA_HORKAGE_NO_LOG_DIR },
>
> + /* Buggy FUA */
> + { "Maxtor", "BANC1G10", ATA_HORKAGE_NO_FUA },
> +
> /* End Marker */
> { }
> };
> @@ -6216,6 +6243,7 @@ static const struct ata_force_param force_tbl[] __initconst = {
> force_horkage_onoff(lpm, ATA_HORKAGE_NOLPM),
> force_horkage_onoff(setxfer, ATA_HORKAGE_NOSETXFER),
> force_horkage_on(dump_id, ATA_HORKAGE_DUMP_ID),
> + force_horkage_onoff(fua, ATA_HORKAGE_NO_FUA),
>
> force_horkage_on(disable, ATA_HORKAGE_DISABLE),
> };
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 4cb914103382..69948e2a8f6d 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -2240,30 +2240,6 @@ static unsigned int ata_msense_rw_recovery(u8 *buf, bool changeable)
> return sizeof(def_rw_recovery_mpage);
> }
>
> -/*
> - * We can turn this into a real blacklist if it's needed, for now just
> - * blacklist any Maxtor BANC1G10 revision firmware
> - */
> -static int ata_dev_supports_fua(u16 *id)
> -{
> - unsigned char model[ATA_ID_PROD_LEN + 1], fw[ATA_ID_FW_REV_LEN + 1];
> -
> - if (!libata_fua)
> - return 0;
> - if (!ata_id_has_fua(id))
> - return 0;
> -
> - ata_id_c_string(id, model, ATA_ID_PROD, sizeof(model));
> - ata_id_c_string(id, fw, ATA_ID_FW_REV, sizeof(fw));
> -
> - if (strcmp(model, "Maxtor"))
> - return 1;
> - if (strcmp(fw, "BANC1G10"))
> - return 1;
> -
> - return 0; /* blacklisted */
> -}
> -
> /**
> * ata_scsiop_mode_sense - Simulate MODE SENSE 6, 10 commands
> * @args: device IDENTIFY data / SCSI command of interest.
> @@ -2287,7 +2263,7 @@ static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
> };
> u8 pg, spg;
> unsigned int ebd, page_control, six_byte;
> - u8 dpofua, bp = 0xff;
> + u8 dpofua = 0, bp = 0xff;
> u16 fp;
>
> six_byte = (scsicmd[0] == MODE_SENSE);
> @@ -2350,9 +2326,7 @@ static unsigned int ata_scsiop_mode_sense(struct ata_scsi_args *args, u8 *rbuf)
> goto invalid_fld;
> }
>
> - dpofua = 0;
> - if (ata_dev_supports_fua(args->id) && (dev->flags & ATA_DFLAG_LBA48) &&
> - (!(dev->flags & ATA_DFLAG_PIO) || dev->multi_count))
> + if (dev->flags & ATA_DFLAG_FUA)
> dpofua = 1 << 4;
>
> if (six_byte) {
> diff --git a/include/linux/libata.h b/include/linux/libata.h
> index 58651f565b36..d30c1288504d 100644
> --- a/include/linux/libata.h
> +++ b/include/linux/libata.h
> @@ -91,6 +91,7 @@ enum {
> ATA_DFLAG_AN = (1 << 7), /* AN configured */
> ATA_DFLAG_TRUSTED = (1 << 8), /* device supports trusted send/recv */
> ATA_DFLAG_DMADIR = (1 << 10), /* device requires DMADIR */
> + ATA_DFLAG_FUA = (1 << 11), /* device supports FUA */
> ATA_DFLAG_CFG_MASK = (1 << 12) - 1,
>
> ATA_DFLAG_PIO = (1 << 12), /* device limited to PIO mode */
> @@ -113,9 +114,9 @@ enum {
> ATA_DFLAG_D_SENSE = (1 << 29), /* Descriptor sense requested */
> ATA_DFLAG_ZAC = (1 << 30), /* ZAC device */
>
> - ATA_DFLAG_FEATURES_MASK = ATA_DFLAG_TRUSTED | ATA_DFLAG_DA | \
> - ATA_DFLAG_DEVSLP | ATA_DFLAG_NCQ_SEND_RECV | \
> - ATA_DFLAG_NCQ_PRIO,
> + ATA_DFLAG_FEATURES_MASK = (ATA_DFLAG_TRUSTED | ATA_DFLAG_DA | \
> + ATA_DFLAG_DEVSLP | ATA_DFLAG_NCQ_SEND_RECV | \
> + ATA_DFLAG_NCQ_PRIO | ATA_DFLAG_FUA),
>
> ATA_DEV_UNKNOWN = 0, /* unknown device */
> ATA_DEV_ATA = 1, /* ATA device */
> @@ -381,6 +382,7 @@ enum {
> ATA_HORKAGE_NO_NCQ_ON_ATI = (1 << 27), /* Disable NCQ on ATI chipset */
> ATA_HORKAGE_NO_ID_DEV_LOG = (1 << 28), /* Identify device log missing */
> ATA_HORKAGE_NO_LOG_DIR = (1 << 29), /* Do not read log directory */
> + ATA_HORKAGE_NO_FUA = (1 << 30), /* Do not use FUA */
>
> /* DMA mask for user DMA control: User visible values; DO NOT
> renumber */
> --
> 2.38.1
>

Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>