Re: [PATCH 24/46] libata: tracepoints for bus-master DMA

Bartlomiej Zolnierkiewicz
2020-02-10T15:21:34Z

On 2/4/20 5:55 PM, Hannes Reinecke wrote:
> Add tracepoints for bus-master DMA and taskfile related functions.
> That allows us to drop the relevant DPRINTK() calls.

The patch drops VPRINTK() calls, not DPRINTK() ones.

Also please move the removal to a separate (post-)patch
(like it has been done for reset tracepoints).

> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---
> drivers/ata/libata-sff.c | 41 +++++++++---------
> include/trace/events/libata.h | 97 +++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 116 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
> index f1799291b4a6..a5e6be6955ae 100644
> --- a/drivers/ata/libata-sff.c
> +++ b/drivers/ata/libata-sff.c
> @@ -22,7 +22,7 @@
> #include <linux/module.h>
> #include <linux/libata.h>
> #include <linux/highmem.h>
> -
> +#include <trace/events/libata.h>
> #include "libata.h"
>
> static struct workqueue_struct *ata_sff_wq;
> @@ -413,12 +413,6 @@ void ata_sff_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
> iowrite8(tf->hob_lbal, ioaddr->lbal_addr);
> iowrite8(tf->hob_lbam, ioaddr->lbam_addr);
> iowrite8(tf->hob_lbah, ioaddr->lbah_addr);
> - VPRINTK("hob: feat 0x%X nsect 0x%X, lba 0x%X 0x%X 0x%X\n",
> - tf->hob_feature,
> - tf->hob_nsect,
> - tf->hob_lbal,
> - tf->hob_lbam,
> - tf->hob_lbah);
> }
>
> if (is_addr) {
> @@ -427,18 +421,10 @@ void ata_sff_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
> iowrite8(tf->lbal, ioaddr->lbal_addr);
> iowrite8(tf->lbam, ioaddr->lbam_addr);
> iowrite8(tf->lbah, ioaddr->lbah_addr);
> - VPRINTK("feat 0x%X nsect 0x%X lba 0x%X 0x%X 0x%X\n",
> - tf->feature,
> - tf->nsect,
> - tf->lbal,
> - tf->lbam,
> - tf->lbah);
> }
>
> - if (tf->flags & ATA_TFLAG_DEVICE) {
> + if (tf->flags & ATA_TFLAG_DEVICE)
> iowrite8(tf->device, ioaddr->device_addr);
> - VPRINTK("device 0x%X\n", tf->device);
> - }
>
> ata_wait_idle(ap);
> }
> @@ -498,8 +484,6 @@ EXPORT_SYMBOL_GPL(ata_sff_tf_read);
> */
> void ata_sff_exec_command(struct ata_port *ap, const struct ata_taskfile *tf)
> {
> - DPRINTK("ata%u: cmd 0x%X\n", ap->print_id, tf->command);
> -
> iowrite8(tf->command, ap->ioaddr.command_addr);
> ata_sff_pause(ap);
> }
> @@ -509,6 +493,7 @@ EXPORT_SYMBOL_GPL(ata_sff_exec_command);
> * ata_tf_to_host - issue ATA taskfile to host controller
> * @ap: port to which command is being issued
> * @tf: ATA taskfile register set
> + * @tag: tag of the associated command
> *
> * Issues ATA taskfile register set to ATA host controller,
> * with proper synchronization with interrupt handler and
> @@ -518,9 +503,12 @@ EXPORT_SYMBOL_GPL(ata_sff_exec_command);
> * spin_lock_irqsave(host lock)
> */
> static inline void ata_tf_to_host(struct ata_port *ap,
> - const struct ata_taskfile *tf)
> + const struct ata_taskfile *tf,
> + unsigned int tag)
> {
> + trace_ata_tf_load(ap, tf);
> ap->ops->sff_tf_load(ap, tf);
> + trace_ata_exec_command(ap, tf, tag);
> ap->ops->sff_exec_command(ap, tf);
> }
>
> @@ -753,6 +741,7 @@ static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
> case ATAPI_PROT_DMA:
> ap->hsm_task_state = HSM_ST_LAST;
> /* initiate bmdma */
> + trace_ata_bmdma_start(ap, &qc->tf, qc->tag);
> ap->ops->bmdma_start(qc);
> break;
> #endif /* CONFIG_ATA_BMDMA */
> @@ -1361,7 +1350,7 @@ unsigned int ata_sff_qc_issue(struct ata_queued_cmd *qc)
> if (qc->tf.flags & ATA_TFLAG_POLLING)
> ata_qc_set_polling(qc);
>
> - ata_tf_to_host(ap, &qc->tf);
> + ata_tf_to_host(ap, &qc->tf, qc->tag);

Wouldn't it be easier to simply pass 'qc' to ata_tf_to_host()?

> ap->hsm_task_state = HSM_ST_LAST;
>
> if (qc->tf.flags & ATA_TFLAG_POLLING)
> @@ -1373,7 +1362,7 @@ unsigned int ata_sff_qc_issue(struct ata_queued_cmd *qc)
> if (qc->tf.flags & ATA_TFLAG_POLLING)
> ata_qc_set_polling(qc);
>
> - ata_tf_to_host(ap, &qc->tf);
> + ata_tf_to_host(ap, &qc->tf, qc->tag);
>
> if (qc->tf.flags & ATA_TFLAG_WRITE) {
> /* PIO data out protocol */
> @@ -1403,7 +1392,7 @@ unsigned int ata_sff_qc_issue(struct ata_queued_cmd *qc)
> if (qc->tf.flags & ATA_TFLAG_POLLING)
> ata_qc_set_polling(qc);
>
> - ata_tf_to_host(ap, &qc->tf);
> + ata_tf_to_host(ap, &qc->tf, qc->tag);
>
> ap->hsm_task_state = HSM_ST_FIRST;
>
> @@ -2737,8 +2726,11 @@ unsigned int ata_bmdma_qc_issue(struct ata_queued_cmd *qc)
> case ATA_PROT_DMA:
> WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
>
> + trace_ata_tf_load(ap, &qc->tf);
> ap->ops->sff_tf_load(ap, &qc->tf); /* load tf registers */
> + trace_ata_bmdma_setup(ap, &qc->tf, qc->tag);
> ap->ops->bmdma_setup(qc); /* set up bmdma */
> + trace_ata_bmdma_start(ap, &qc->tf, qc->tag);
> ap->ops->bmdma_start(qc); /* initiate bmdma */
> ap->hsm_task_state = HSM_ST_LAST;
> break;
> @@ -2746,7 +2738,9 @@ unsigned int ata_bmdma_qc_issue(struct ata_queued_cmd *qc)
> case ATAPI_PROT_DMA:
> WARN_ON_ONCE(qc->tf.flags & ATA_TFLAG_POLLING);
>
> + trace_ata_tf_load(ap, &qc->tf);
> ap->ops->sff_tf_load(ap, &qc->tf); /* load tf registers */
> + trace_ata_bmdma_setup(ap, &qc->tf, qc->tag);
> ap->ops->bmdma_setup(qc); /* set up bmdma */
> ap->hsm_task_state = HSM_ST_FIRST;
>
> @@ -2794,6 +2788,7 @@ unsigned int ata_bmdma_port_intr(struct ata_port *ap, struct ata_queued_cmd *qc)
> return ata_sff_idle_irq(ap);
>
> /* before we do anything else, clear DMA-Start bit */
> + trace_ata_bmdma_stop(ap, &qc->tf, qc->tag);
> ap->ops->bmdma_stop(qc);
> bmdma_stopped = true;
>
> @@ -2873,6 +2868,7 @@ void ata_bmdma_error_handler(struct ata_port *ap)
> thaw = true;
> }
>
> + trace_ata_bmdma_stop(ap, &qc->tf, qc->tag);
> ap->ops->bmdma_stop(qc);
>
> /* if we're gonna thaw, make sure IRQ is clear */
> @@ -2906,6 +2902,7 @@ void ata_bmdma_post_internal_cmd(struct ata_queued_cmd *qc)
>
> if (ata_is_dma(qc->tf.protocol)) {
> spin_lock_irqsave(ap->lock, flags);
> + trace_ata_bmdma_stop(ap, &qc->tf, qc->tag);
> ap->ops->bmdma_stop(qc);
> spin_unlock_irqrestore(ap->lock, flags);
> }
> diff --git a/include/trace/events/libata.h b/include/trace/events/libata.h
> index e9fb4d44eeac..476acf823928 100644
> --- a/include/trace/events/libata.h
> +++ b/include/trace/events/libata.h
> @@ -291,6 +291,103 @@ DEFINE_EVENT(ata_qc_complete_template, ata_qc_complete_done,
> TP_PROTO(struct ata_queued_cmd *qc),
> TP_ARGS(qc));
>
> +TRACE_EVENT(ata_tf_load,
> +
> + TP_PROTO(struct ata_port *ap, const struct ata_taskfile *tf),
> +
> + TP_ARGS(ap, tf),
> +
> + TP_STRUCT__entry(
> + __field( unsigned int, ata_port )
> + __field( unsigned char, cmd )
> + __field( unsigned char, dev )
> + __field( unsigned char, lbal )
> + __field( unsigned char, lbam )
> + __field( unsigned char, lbah )
> + __field( unsigned char, nsect )
> + __field( unsigned char, feature )
> + __field( unsigned char, hob_lbal )
> + __field( unsigned char, hob_lbam )
> + __field( unsigned char, hob_lbah )
> + __field( unsigned char, hob_nsect )
> + __field( unsigned char, hob_feature )
> + __field( unsigned char, proto )
> + __field( unsigned long, flags )

'flags' field doesn't seem to be used?

> + ),
> +
> + TP_fast_assign(
> + __entry->ata_port = ap->print_id;
> + __entry->proto = tf->protocol;
> + __entry->cmd = tf->command;
> + __entry->dev = tf->device;
> + __entry->lbal = tf->lbal;
> + __entry->lbam = tf->lbam;
> + __entry->lbah = tf->lbah;
> + __entry->hob_lbal = tf->hob_lbal;
> + __entry->hob_lbam = tf->hob_lbam;
> + __entry->hob_lbah = tf->hob_lbah;
> + __entry->feature = tf->feature;
> + __entry->hob_feature = tf->hob_feature;
> + __entry->nsect = tf->nsect;
> + __entry->hob_nsect = tf->hob_nsect;
> + ),
> +
> + TP_printk("ata_port=%u proto=%s cmd=%s%s " \
> + " tf=(%02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x)",
> + __entry->ata_port,
> + show_protocol_name(__entry->proto),
> + show_opcode_name(__entry->cmd),
> + __parse_subcmd(__entry->cmd, __entry->feature, __entry->hob_nsect),
> + __entry->cmd, __entry->feature, __entry->nsect,
> + __entry->lbal, __entry->lbam, __entry->lbah,
> + __entry->hob_feature, __entry->hob_nsect,
> + __entry->hob_lbal, __entry->hob_lbam, __entry->hob_lbah,
> + __entry->dev)
> +);
> +
> +DECLARE_EVENT_CLASS(ata_exec_command_template,
> +
> + TP_PROTO(struct ata_port *ap, const struct ata_taskfile *tf, unsigned int tag),
> +
> + TP_ARGS(ap, tf, tag),
> +
> + TP_STRUCT__entry(
> + __field( unsigned int, ata_port )
> + __field( unsigned int, tag )
> + __field( unsigned char, cmd )
> + __field( unsigned char, proto )
> + ),
> +
> + TP_fast_assign(
> + __entry->ata_port = ap->print_id;
> + __entry->tag = tag;
> + __entry->proto = tf->protocol;
> + __entry->cmd = tf->command;
> + ),
> +
> + TP_printk("ata_port=%u cmd=%s%s tag=%d",
> + __entry->ata_port,
> + show_protocol_name(__entry->proto),
> + show_opcode_name(__entry->cmd),

Please keep both new events consistent regarding 'proto' and
'cmd' fields printing (add "proto=%s" in this event or rework
printing in ata_tf_load one).

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

> + __entry->tag)
> +);
> +
> +DEFINE_EVENT(ata_exec_command_template, ata_exec_command,
> + TP_PROTO(struct ata_port *ap, const struct ata_taskfile *tf, unsigned int tag),
> + TP_ARGS(ap, tf, tag));
> +
> +DEFINE_EVENT(ata_exec_command_template, ata_bmdma_setup,
> + TP_PROTO(struct ata_port *ap, const struct ata_taskfile *tf, unsigned int tag),
> + TP_ARGS(ap, tf, tag));
> +
> +DEFINE_EVENT(ata_exec_command_template, ata_bmdma_start,
> + TP_PROTO(struct ata_port *ap, const struct ata_taskfile *tf, unsigned int tag),
> + TP_ARGS(ap, tf, tag));
> +
> +DEFINE_EVENT(ata_exec_command_template, ata_bmdma_stop,
> + TP_PROTO(struct ata_port *ap, const struct ata_taskfile *tf, unsigned int tag),
> + TP_ARGS(ap, tf, tag));
> +
> TRACE_EVENT(ata_eh_link_autopsy,
>
> TP_PROTO(struct ata_device *dev, unsigned int eh_action, unsigned int eh_err_mask),