RE: [RFC PATCH v5 2/3] ufs: exynos: introduce command history

["Kiwoong Kim" <kwmad.kim@samsung.com>]

> Hi Kiwoong,
> 
> > -----Original Message-----
> > From: Kiwoong Kim <kwmad.kim@samsung.com>
> > Sent: 11 July 2020 12:28
> > To: linux-scsi@vger.kernel.org; alim.akhtar@samsung.com;
> > avri.altman@wdc.com; jejb@linux.ibm.com; martin.petersen@oracle.com;
> > beanhuo@micron.com; asutoshd@codeaurora.org; cang@codeaurora.org;
> > bvanassche@acm.org; grant.jung@samsung.com; sc.suh@samsung.com;
> > hy50.seo@samsung.com; sh425.lee@samsung.com
> > Cc: Kiwoong Kim <kwmad.kim@samsung.com>
> > Subject: [RFC PATCH v5 2/3] ufs: exynos: introduce command history
> >
> > This includes functions to record contexts of incoming commands in a
> > circular queue. ufshcd.c has already some function tracer calls to get
> > command history but ftrace would be gone when system dies before you
> > get the information, such as panic cases.
> >
> > This patch also implements callbacks compl_xfer_req to store IO
> > contexts at completion times.
> >
> > When you turn on CONFIG_SCSI_UFS_EXYNOS_CMD_LOG, the driver collects
> > the information from incoming commands in the circular queue.
> >
> > Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
> > +void exynos_ufs_cmd_log_start(struct ufs_exynos_handle *handle,
> > +			      struct ufs_hba *hba, int tag) {
> > +	struct ufs_s_dbg_mgr *mgr = (struct ufs_s_dbg_mgr *)handle->private;
> > +	struct scsi_cmnd *cmd = hba->lrb[tag].cmd;
> > +	int cpu = raw_smp_processor_id();
> > +	struct cmd_data *cmd_log = &mgr->cmd_log;	/* temp buffer to put
> > */
> > +	u64 lba = 0;
> > +	u32 sct = 0;
> > +
> > +	if (mgr->active == 0)
> > +		return;
> > +
> > +	cmd_log->start_time = cpu_clock(cpu);
> > +	cmd_log->op = cmd->cmnd[0];
> > +	cmd_log->tag = tag;
> > +
> > +	/* This function runtime is protected by spinlock from outside */
> > +	cmd_log->outstanding_reqs = hba->outstanding_reqs;
> > +
> > +	/* Now assume using WRITE_10 and READ_10 */
> > +	put_unaligned(cpu_to_le32(*(u32 *)cmd->cmnd[2]), (u32 *)&lba);
> This gives compilation error, you need to include <asm-
> generic/unaligned.h> Also type casting to u32 is not needed, will give
> build warnings.
> 
> > +	put_unaligned(cpu_to_le16(*(u16 *)cmd->cmnd[7]), (u16 *)&sct);
> Type casting to u16 is not needed.
> 
> > +	if (cmd->cmnd[0] != UNMAP)
> > +		cmd_log->lba = lba;
> > +
> > +	cmd_log->sct = sct;
> > +	cmd_log->retries = cmd->allowed;
> > +
> > +	ufs_s_put_cmd_log(mgr, cmd_log);
> > +}
> > +
> > +void exynos_ufs_cmd_log_end(struct ufs_exynos_handle *handle,
> > +			    struct ufs_hba *hba, int tag)
> > +{
> > +	struct ufs_s_dbg_mgr *mgr = (struct ufs_s_dbg_mgr *)handle->private;
> > +	struct scsi_cmnd *cmd = hba->lrb[tag].cmd;
> Unused variable "cmd"
> 
> > +	struct ufs_cmd_info *cmd_info = &mgr->cmd_info;
> > +	int cpu = raw_smp_processor_id();
> > +
> > +	if (mgr->active == 0)
> > +		return;
> > +
> > +	cmd_info->pdata[tag]->end_time = cpu_clock(cpu); }
> > +
> > +int exynos_ufs_init_dbg(struct ufs_exynos_handle *handle, struct
> > +device
> > +*dev) {
> > +	struct ufs_s_dbg_mgr *mgr;
> > +
> > +	mgr = devm_kzalloc(dev, sizeof(struct ufs_s_dbg_mgr), GFP_KERNEL);
> > +	if (!mgr)
> > +		return -ENOMEM;
> > +	handle->private = (void *)mgr;
> > +	mgr->handle = handle;
> > +	mgr->active = 1;
> > +
> > +	/* cmd log */
> > +	spin_lock_init(&mgr->cmd_lock);
> > +
> > +	return 0;
> > +}
> > +MODULE_AUTHOR("Kiwoong Kim <kwmad.kim@samsung.com>");
> > +MODULE_DESCRIPTION("Exynos UFS debug information");
> > +MODULE_LICENSE("GPL"); MODULE_VERSION("0.1");
> May be "GPL v2"
> 
> > diff --git a/drivers/scsi/ufs/ufs-exynos-if.h
> > b/drivers/scsi/ufs/ufs-exynos-if.h
> > new file mode 100644
> > 2.7.4
> 

Have Checked what you commented.

Thanks.
Kiwoong Kim