On Mon, Aug 26, 2024 at 04:31:06PM +0900, Damien Le Moal wrote:
> The command duration limits (CDL) log buffer of struct ata_device is
> needed only if a device actually supports CDL. The same applies to the
> ncq_sense_log buffer.
>
> Group these 2 buffers into a new structure ata_cdl defining both buffers
> as embedded buffers (no allocation needed) and allocate this structure
> from ata_dev_config_cdl() only for devices that support CDL.
>
> The functions ata_dev_init_cdl_resources() and
> ata_dev_cleanup_cdl_resources() are defined to manage this new structure
> allocation, initialization and cleanup when a device is removed.
> ata_dev_cleanup_cdl_resources() is called from ata_tdev_free().
>
> Note that the cdl log buffer name is changed to desc_log_buf to make it
> clearer what it is.
>
> This change reduces the size of struct ata_device and reduces memory
> usage for ATA devices that do not support CDL.
>
> Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
Like previous comment, as long as sector_buf belongs to struct ata_port,
it seems a bit weird to keep this in struct ata_device.
Perhaps we can move sector_buf to struct ata_device?
(and modify the ata_read_log() functions to not take a buffer,
as the buffer would not be in the struct ata_device, which we already
supply to the ata_read_log() functions as the first argument.)
If we do that, then I think it is okay to keep a struct ata_cdl
in struct ata_device. Although I still don't like cleaning this
up in ata_tdev_() functions.
Perhaps we could call ata_device_cleanup()/ata_device_free_resource()
from ata_port_free() ?
ata_tport_release() will call ata_host_put().
ata_host_put() calls kref_put(&host->kref, ata_host_release);
ata_host_release() calls ata_port_free().
But ata_tport_add() is simply adding the sysfs entry IMO.
The sysfs entry takes a ata_host reference.
Once the refcount is zero, it will be freed.
Which is why I think that it makes more sense to clean this up in in
ata_port_free() (at least with the current design where the fixed size
ata_device array is part of struct ata_port (via struct ata_link)).
Perhaps something like:
void ata_port_free(struct ata_port *ap)
{
....
ata_for_each_link (link, ap, ...) {
ata_for_each_dev (dev, link, ...) {
ata_device_cleanup(dev);
}
}
}
Kind regards,
Niklas
> ---
> drivers/ata/libata-core.c | 56 +++++++++++++++++++++-------------
> drivers/ata/libata-sata.c | 2 +-
> drivers/ata/libata-scsi.c | 2 +-
> drivers/ata/libata-transport.c | 4 +--
> drivers/ata/libata.h | 1 +
> include/linux/libata.h | 18 +++++++++--
> 6 files changed, 54 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index 6a1d300dd1f5..bcee96e29b34 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -2475,12 +2475,41 @@ static void ata_dev_config_trusted(struct ata_device *dev)
> dev->flags |= ATA_DFLAG_TRUSTED;
> }
>
> +static int ata_dev_init_cdl_resources(struct ata_device *dev)
> +{
> + struct ata_cdl *cdl = dev->cdl;
> + unsigned int err_mask;
> +
> + if (!cdl) {
> + cdl = kzalloc(sizeof(struct ata_cdl), GFP_KERNEL);
> + if (!cdl)
> + return -ENOMEM;
> + dev->cdl = cdl;
> + }
> +
> + err_mask = ata_read_log_page(dev, ATA_LOG_CDL, 0, cdl->desc_log_buf,
> + ATA_LOG_CDL_SIZE / ATA_SECT_SIZE);
> + if (err_mask) {
> + ata_dev_warn(dev, "Read Command Duration Limits log failed\n");
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> +void ata_dev_cleanup_cdl_resources(struct ata_device *dev)
> +{
> + kfree(dev->cdl);
> + dev->cdl = NULL;
> +}
> +
> static void ata_dev_config_cdl(struct ata_device *dev)
> {
> struct ata_port *ap = dev->link->ap;
> unsigned int err_mask;
> bool cdl_enabled;
> u64 val;
> + int ret;
>
> if (ata_id_major_version(dev->id) < 11)
> goto not_supported;
> @@ -2575,37 +2604,20 @@ static void ata_dev_config_cdl(struct ata_device *dev)
> }
> }
>
> - /*
> - * Allocate a buffer to handle reading the sense data for successful
> - * NCQ Commands log page for commands using a CDL with one of the limit
> - * policy set to 0xD (successful completion with sense data available
> - * bit set).
> - */
> - if (!dev->ncq_sense_buf) {
> - dev->ncq_sense_buf = kmalloc(ATA_LOG_SENSE_NCQ_SIZE, GFP_KERNEL);
> - if (!dev->ncq_sense_buf)
> - goto not_supported;
> - }
> -
> - /*
> - * Command duration limits is supported: cache the CDL log page 18h
> - * (command duration descriptors).
> - */
> - err_mask = ata_read_log_page(dev, ATA_LOG_CDL, 0, ap->sector_buf, 1);
> - if (err_mask) {
> - ata_dev_warn(dev, "Read Command Duration Limits log failed\n");
> + /* CDL is supported: allocate and initialize needed resources. */
> + ret = ata_dev_init_cdl_resources(dev);
> + if (ret) {
> + ata_dev_warn(dev, "Initialize CDL resources failed\n");
> goto not_supported;
> }
>
> - memcpy(dev->cdl, ap->sector_buf, ATA_LOG_CDL_SIZE);
> dev->flags |= ATA_DFLAG_CDL;
>
> return;
>
> not_supported:
> dev->flags &= ~(ATA_DFLAG_CDL | ATA_DFLAG_CDL_ENABLED);
> - kfree(dev->ncq_sense_buf);
> - dev->ncq_sense_buf = NULL;
> + ata_dev_cleanup_cdl_resources(dev);
> }
>
> static int ata_dev_config_lba(struct ata_device *dev)
> diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
> index 50ea254a213d..e05fb09af061 100644
> --- a/drivers/ata/libata-sata.c
> +++ b/drivers/ata/libata-sata.c
> @@ -1505,7 +1505,7 @@ int ata_eh_get_ncq_success_sense(struct ata_link *link)
> {
> struct ata_device *dev = link->device;
> struct ata_port *ap = dev->link->ap;
> - u8 *buf = dev->ncq_sense_buf;
> + u8 *buf = dev->cdl->ncq_sense_log_buf;
> struct ata_queued_cmd *qc;
> unsigned int err_mask, tag;
> u8 *sense, sk = 0, asc = 0, ascq = 0;
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index a3ffce4b218d..7fed924d6561 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -2259,7 +2259,7 @@ static inline u16 ata_xlat_cdl_limit(u8 *buf)
> static unsigned int ata_msense_control_spgt2(struct ata_device *dev, u8 *buf,
> u8 spg)
> {
> - u8 *b, *cdl = dev->cdl, *desc;
> + u8 *b, *cdl = dev->cdl->desc_log_buf, *desc;
> u32 policy;
> int i;
>
> diff --git a/drivers/ata/libata-transport.c b/drivers/ata/libata-transport.c
> index 14f50c91ceb9..add230c0d51e 100644
> --- a/drivers/ata/libata-transport.c
> +++ b/drivers/ata/libata-transport.c
> @@ -671,9 +671,7 @@ static int ata_tdev_match(struct attribute_container *cont,
> */
> static void ata_tdev_free(struct ata_device *dev)
> {
> - kfree(dev->ncq_sense_buf);
> - dev->ncq_sense_buf = NULL;
> -
> + ata_dev_cleanup_cdl_resources(dev);
> transport_destroy_device(&dev->tdev);
> put_device(&dev->tdev);
> }
> diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
> index 5ca17784a350..df11f923e1a2 100644
> --- a/drivers/ata/libata.h
> +++ b/drivers/ata/libata.h
> @@ -89,6 +89,7 @@ extern int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg);
> extern const char *sata_spd_string(unsigned int spd);
> extern unsigned int ata_read_log_page(struct ata_device *dev, u8 log,
> u8 page, void *buf, unsigned int sectors);
> +void ata_dev_cleanup_cdl_resources(struct ata_device *dev);
>
> #define to_ata_port(d) container_of(d, struct ata_port, tdev)
>
> diff --git a/include/linux/libata.h b/include/linux/libata.h
> index 3fb6980c8aa1..37a5509adc77 100644
> --- a/include/linux/libata.h
> +++ b/include/linux/libata.h
> @@ -700,6 +700,21 @@ struct ata_cpr_log {
> struct ata_cpr cpr[] __counted_by(nr_cpr);
> };
>
> +struct ata_cdl {
> + /*
> + * Buffer to cache the CDL log page 18h (command duration descriptors)
> + * for SCSI-ATA translation.
> + */
> + u8 desc_log_buf[ATA_LOG_CDL_SIZE];
> +
> + /*
> + * Buffer to handle reading the sense data for successful NCQ Commands
> + * log page for commands using a CDL with one of the limits policy set
> + * to 0xD (successful completion with sense data available bit set).
> + */
> + u8 ncq_sense_log_buf[ATA_LOG_SENSE_NCQ_SIZE];
> +};
> +
> struct ata_device {
> struct ata_link *link;
> unsigned int devno; /* 0 or 1 */
> @@ -763,8 +778,7 @@ struct ata_device {
> struct ata_cpr_log *cpr_log;
>
> /* Command Duration Limits support */
> - u8 *ncq_sense_buf;
> - u8 cdl[ATA_LOG_CDL_SIZE];
> + struct ata_cdl *cdl;
>
> /* error history */
> int spdn_cnt;
> --
> 2.46.0
>
