Heitor,
Very nice patch. A few comments below.
Thanks!
Brian
On 07/27/2016 09:39 AM, Heitor Ricardo Alves de Siqueira wrote:
> This patch implements functions for pushing HCAM (host controlled
> asynchronous messages) error buffers to userspace through sysfs attributes.
> Reads to the "async_err_log" attribute will result in a single HCAM buffer
> being copied to userspace; one can process the next HCAM buffer by writing
> any string to the same attribute.
>
> A new list was added to the ioa_cfg structure to store the HCAM buffers for
> later reporting. Another read-only sysfs attribute ("current_hcam_count")
> indicates how many buffers are being held by this report queue. We also
> send a KOBJ_CHANGE event whenever a new HCAM buffer is made available to
> userspace.
>
> Signed-off-by: Heitor Ricardo Alves de Siqueira <hal...@linux.vnet.ibm.com>
> Signed-off-by: Gabriel Krisman Bertazi <kris...@linux.vnet.ibm.com>
> ---
> drivers/scsi/ipr.c | 168
> +++++++++++++++++++++++++++++++++++++++++++++++++----
> drivers/scsi/ipr.h | 7 ++-
> 2 files changed, 161 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
> index d6803a9e5ab8..bdd36f6d1569 100644
> --- a/drivers/scsi/ipr.c
> +++ b/drivers/scsi/ipr.c
> @@ -1472,7 +1472,7 @@ static void ipr_process_ccn(struct ipr_cmnd *ipr_cmd)
> struct ipr_hostrcb *hostrcb = ipr_cmd->u.hostrcb;
> u32 ioasc = be32_to_cpu(ipr_cmd->s.ioasa.hdr.ioasc);
>
> - list_del(&hostrcb->queue);
> + list_del_init(&hostrcb->queue);
> list_add_tail(&ipr_cmd->queue, &ipr_cmd->hrrq->hrrq_free_q);
>
> if (ioasc) {
> @@ -2551,6 +2551,41 @@ static void ipr_handle_log_data(struct ipr_ioa_cfg
> *ioa_cfg,
> }
> }
>
> +static struct ipr_hostrcb *ipr_get_free_hostrcb(struct ipr_ioa_cfg *ioa)
> +{
> + struct ipr_hostrcb *hostrcb;
> +
> + hostrcb = list_first_entry_or_null(&ioa->hostrcb_free_q,
> + struct ipr_hostrcb, queue);
> +
> + if (unlikely(!hostrcb)) {
> + dev_err(&ioa->pdev->dev,
> + "hcam pool exausted. Reclaiming reserved
> hostrcb\n");
Suggest rewording to: "Reclaiming async error buffers." Also change to dev_info.
> +
> + hostrcb = list_first_entry_or_null(&ioa->hostrcb_report_q,
> + struct ipr_hostrcb, queue);
> + }
> +
> + list_del_init(&hostrcb->queue);
> + return hostrcb;
> +}
> +
> +static int ipr_report_error(struct ipr_ioa_cfg *ioa,
> + struct ipr_hostrcb *hostrcb)
> +{
> + u32 ioasc;
> + struct ipr_hcam *hcam = &hostrcb->hcam;
> + struct ipr_error_table_t hcam_error_entry;
> +
> + if (ioa->sis64)
> + ioasc = be32_to_cpu(hcam->u.error64.fd_ioasc);
> + else
> + ioasc = be32_to_cpu(hcam->u.error.fd_ioasc);
> +
> + hcam_error_entry = ipr_error_table[ipr_get_error(ioasc)];
> + return hcam_error_entry.log_hcam >= ioa->log_level;
Let's remove this function altogether and ship everything out to
userspace and let userspace do any filtering it desires rather
than overloading the log_level, which currently helps filter what
goes to dmesg.
> +}
> +
> /**
> * ipr_process_error - Op done function for an adapter error log.
> * @ipr_cmd: ipr command struct
> @@ -2568,13 +2603,14 @@ static void ipr_process_error(struct ipr_cmnd
> *ipr_cmd)
> struct ipr_hostrcb *hostrcb = ipr_cmd->u.hostrcb;
> u32 ioasc = be32_to_cpu(ipr_cmd->s.ioasa.hdr.ioasc);
> u32 fd_ioasc;
> + static const char * const env[] = { "ASYNC_ERR_LOG=1", NULL};
>
> if (ioa_cfg->sis64)
> fd_ioasc = be32_to_cpu(hostrcb->hcam.u.error64.fd_ioasc);
> else
> fd_ioasc = be32_to_cpu(hostrcb->hcam.u.error.fd_ioasc);
>
> - list_del(&hostrcb->queue);
> + list_del_init(&hostrcb->queue);
> list_add_tail(&ipr_cmd->queue, &ipr_cmd->hrrq->hrrq_free_q);
>
> if (!ioasc) {
> @@ -2587,6 +2623,13 @@ static void ipr_process_error(struct ipr_cmnd *ipr_cmd)
> "Host RCB failed with IOASC: 0x%08X\n", ioasc);
> }
>
> + if (ipr_report_error(ioa_cfg, hostrcb)) {
> + list_add_tail(&hostrcb->queue, &ioa_cfg->hostrcb_report_q);
> + hostrcb = ipr_get_free_hostrcb(ioa_cfg);
> + kobject_uevent_env(&ioa_cfg->host->shost_dev.kobj,
> + KOBJ_CHANGE, env);
> + }
> +
> ipr_send_hcam(ioa_cfg, IPR_HCAM_CDB_OP_CODE_LOG_DATA, hostrcb);
> }
>
> @@ -4089,6 +4132,89 @@ static struct device_attribute ipr_ioa_fw_type_attr = {
> .show = ipr_show_fw_type
> };
>
> +static ssize_t ipr_read_async_err_log(struct file *filep, struct kobject
> *kobj,
> + struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
Indentation here looks a little strange.
> +{
> + struct device *cdev = container_of(kobj, struct device, kobj);
> + struct Scsi_Host *shost = class_to_shost(cdev);
> + struct ipr_ioa_cfg *ioa_cfg = (struct ipr_ioa_cfg *)shost->hostdata;
> + struct ipr_hostrcb *hostrcb;
> + unsigned long lock_flags = 0;
> + int ret;
> +
> + spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
> + hostrcb = list_first_entry_or_null(&ioa_cfg->hostrcb_report_q,
> + struct ipr_hostrcb, queue);
> + spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
> + if (!hostrcb)
> + return 0;
> +
> +
> + ret = memory_read_from_buffer(buf, count, &off, &hostrcb->hcam,
> + sizeof(hostrcb->hcam));
Can you tuck this memory_read_from_buffer up under the spin_lock above? Since
the hostrcb's don't have any refcounting associated with them, I'm worried about
racing with the adapter remove path.
> + return ret;
> +}
> +
> +static ssize_t ipr_next_async_err_log(struct file *filep, struct kobject
> *kobj,
> + struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count)
> +{
> + struct device *cdev = container_of(kobj, struct device, kobj);
> + struct Scsi_Host *shost = class_to_shost(cdev);
> + struct ipr_ioa_cfg *ioa_cfg = (struct ipr_ioa_cfg *)shost->hostdata;
> + struct ipr_hostrcb *hostrcb;
> + unsigned long lock_flags = 0;
> +
> + spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
> + hostrcb = list_first_entry_or_null(&ioa_cfg->hostrcb_report_q,
> + struct ipr_hostrcb, queue);
> + if (!hostrcb) {
> + spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
> + return 0;
> + }
> +
> + /* Reclaim hostrcb before exit */
> + list_move_tail(&hostrcb->queue, &ioa_cfg->hostrcb_free_q);
> + spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
> + return count;
> +}
> +
> +static struct bin_attribute ipr_ioa_async_err_log = {
> + .attr = {
> + .name = "async_err_log",
> + .mode = S_IRUGO | S_IWUSR,
> + },
> + .size = 0,
No need to initialize static variables to zero.
> + .read = ipr_read_async_err_log,
> + .write = ipr_next_async_err_log
> +};
> +
> +static ssize_t ipr_show_current_hcam_count(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct Scsi_Host *shost = class_to_shost(dev);
> + struct ipr_ioa_cfg *ioa_cfg = (struct ipr_ioa_cfg *)shost->hostdata;
> + struct ipr_hostrcb *hostrcb, *temp;
> + int len, hcam_count = 0;
> + unsigned long lock_flags = 0;
> +
> + spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
> + list_for_each_entry_safe(hostrcb, temp,
> + &ioa_cfg->hostrcb_report_q, queue) {
> + hcam_count++;
> + }
> + spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
> + len = snprintf(buf, PAGE_SIZE, "%d\n", hcam_count);
> + return len;
> +}
> +
> +static struct device_attribute ipr_ioa_current_hcam_count = {
> + .attr = {
> + .name = "current_hcam_count",
> + .mode = S_IRUGO,
> + },
> + .show = ipr_show_current_hcam_count
> +};
This attribute doesn't seem necessary. We should be able to just read the
async_err_log attribute and see if there is any data there, can't we?
> +
> static struct device_attribute *ipr_ioa_attrs[] = {
> &ipr_fw_version_attr,
> &ipr_log_level_attr,
--
Brian King
Power Linux I/O
IBM Linux Technology Center
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