scsi: ipr: Add asynchronous error notification

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. 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 <halves@linux.vnet.ibm.com>
Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 118 insertions, 14 deletions

diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index bf85974be862..5ecc32cecd10 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -1473,7 +1473,7 @@ 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) {
@@ -2552,6 +2552,23 @@ 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_info(&ioa->pdev->dev, "Reclaiming async error buffers.");
+                hostrcb = list_first_entry_or_null(&ioa->hostrcb_report_q,
+                                                struct ipr_hostrcb, queue);
+        }
+
+        list_del_init(&hostrcb->queue);
+        return hostrcb;
+}
+
 /**
  * ipr_process_error - Op done function for an adapter error log.
  * @ipr_cmd:    ipr command struct
@@ -2569,13 +2586,14 @@ 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;
+        char *envp[] = { "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) {
@@ -2588,6 +2606,10 @@ static void ipr_process_error(struct ipr_cmnd *ipr_cmd)
                         "Host RCB failed with IOASC: 0x%08X\n", ioasc);
         }
 
+        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, envp);
+
         ipr_send_hcam(ioa_cfg, IPR_HCAM_CDB_OP_CODE_LOG_DATA, hostrcb);
 }
 
@@ -4095,6 +4117,64 @@ 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)
+{
+        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);
+        if (!hostrcb) {
+                spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
+                return 0;
+        }
+        ret = memory_read_from_buffer(buf, count, &off, &hostrcb->hcam,
+                                sizeof(hostrcb->hcam));
+        spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
+        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 count;
+        }
+
+        /* 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,
+        .read = ipr_read_async_err_log,
+        .write = ipr_next_async_err_log
+};
+
 static struct device_attribute *ipr_ioa_attrs[] = {
         &ipr_fw_version_attr,
         &ipr_log_level_attr,
@@ -7026,8 +7106,7 @@ static int ipr_ioa_reset_done(struct ipr_cmnd *ipr_cmd)
 {
         struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
         struct ipr_resource_entry *res;
-        struct ipr_hostrcb *hostrcb, *temp;
-        int i = 0, j;
+        int j;
 
         ENTER;
         ioa_cfg->in_reset_reload = 0;
@@ -7048,12 +7127,16 @@ static int ipr_ioa_reset_done(struct ipr_cmnd *ipr_cmd)
         }
         schedule_work(&ioa_cfg->work_q);
 
-        list_for_each_entry_safe(hostrcb, temp, &ioa_cfg->hostrcb_free_q, queue) {
-                list_del(&hostrcb->queue);
-                if (i++ < IPR_NUM_LOG_HCAMS)
-                        ipr_send_hcam(ioa_cfg, IPR_HCAM_CDB_OP_CODE_LOG_DATA, hostrcb);
+        for (j = 0; j < IPR_NUM_HCAMS; j++) {
+                list_del_init(&ioa_cfg->hostrcb[j]->queue);
+                if (j < IPR_NUM_LOG_HCAMS)
+                        ipr_send_hcam(ioa_cfg,
+                                IPR_HCAM_CDB_OP_CODE_LOG_DATA,
+                                ioa_cfg->hostrcb[j]);
                 else
-                        ipr_send_hcam(ioa_cfg, IPR_HCAM_CDB_OP_CODE_CONFIG_CHANGE, hostrcb);
+                        ipr_send_hcam(ioa_cfg,
+                                IPR_HCAM_CDB_OP_CODE_CONFIG_CHANGE,
+                                ioa_cfg->hostrcb[j]);
         }
 
         scsi_report_bus_reset(ioa_cfg->host, IPR_VSET_BUS);
@@ -8335,7 +8418,7 @@ static void ipr_get_unit_check_buffer(struct ipr_ioa_cfg *ioa_cfg)
 
         hostrcb = list_entry(ioa_cfg->hostrcb_free_q.next,
                              struct ipr_hostrcb, queue);
-        list_del(&hostrcb->queue);
+        list_del_init(&hostrcb->queue);
         memset(&hostrcb->hcam, 0, sizeof(hostrcb->hcam));
 
         rc = ipr_get_ldump_data_section(ioa_cfg,
@@ -9332,7 +9415,7 @@ static void ipr_free_mem(struct ipr_ioa_cfg *ioa_cfg)
         dma_free_coherent(&ioa_cfg->pdev->dev, ioa_cfg->cfg_table_size,
                           ioa_cfg->u.cfg_table, ioa_cfg->cfg_table_dma);
 
-        for (i = 0; i < IPR_NUM_HCAMS; i++) {
+        for (i = 0; i < IPR_MAX_HCAMS; i++) {
                 dma_free_coherent(&ioa_cfg->pdev->dev,
                                   sizeof(struct ipr_hostrcb),
                                   ioa_cfg->hostrcb[i],
@@ -9572,7 +9655,7 @@ static int ipr_alloc_mem(struct ipr_ioa_cfg *ioa_cfg)
         if (!ioa_cfg->u.cfg_table)
                 goto out_free_host_rrq;
 
-        for (i = 0; i < IPR_NUM_HCAMS; i++) {
+        for (i = 0; i < IPR_MAX_HCAMS; i++) {
                 ioa_cfg->hostrcb[i] = dma_alloc_coherent(&pdev->dev,
                                                          sizeof(struct ipr_hostrcb),
                                                          &ioa_cfg->hostrcb_dma[i],
@@ -9714,6 +9797,7 @@ static void ipr_init_ioa_cfg(struct ipr_ioa_cfg *ioa_cfg,
 
         INIT_LIST_HEAD(&ioa_cfg->hostrcb_free_q);
         INIT_LIST_HEAD(&ioa_cfg->hostrcb_pending_q);
+        INIT_LIST_HEAD(&ioa_cfg->hostrcb_report_q);
         INIT_LIST_HEAD(&ioa_cfg->free_res_q);
         INIT_LIST_HEAD(&ioa_cfg->used_res_q);
         INIT_WORK(&ioa_cfg->work_q, ipr_worker_thread);
@@ -10352,6 +10436,8 @@ static void ipr_remove(struct pci_dev *pdev)
                               &ipr_trace_attr);
         ipr_remove_dump_file(&ioa_cfg->host->shost_dev.kobj,
                              &ipr_dump_attr);
+        sysfs_remove_bin_file(&ioa_cfg->host->shost_dev.kobj,
+                        &ipr_ioa_async_err_log);
         scsi_remove_host(ioa_cfg->host);
 
         __ipr_remove(pdev);
@@ -10400,10 +10486,25 @@ static int ipr_probe(struct pci_dev *pdev, const struct pci_device_id *dev_id)
                 return rc;
         }
 
+        rc = sysfs_create_bin_file(&ioa_cfg->host->shost_dev.kobj,
+                        &ipr_ioa_async_err_log);
+
+        if (rc) {
+                ipr_remove_dump_file(&ioa_cfg->host->shost_dev.kobj,
+                                &ipr_dump_attr);
+                ipr_remove_trace_file(&ioa_cfg->host->shost_dev.kobj,
+                                &ipr_trace_attr);
+                scsi_remove_host(ioa_cfg->host);
+                __ipr_remove(pdev);
+                return rc;
+        }
+
         rc = ipr_create_dump_file(&ioa_cfg->host->shost_dev.kobj,
                                    &ipr_dump_attr);
 
         if (rc) {
+                sysfs_remove_bin_file(&ioa_cfg->host->shost_dev.kobj,
+                                      &ipr_ioa_async_err_log);
                 ipr_remove_trace_file(&ioa_cfg->host->shost_dev.kobj,
                                       &ipr_trace_attr);
                 scsi_remove_host(ioa_cfg->host);
diff --git a/drivers/scsi/ipr.h b/drivers/scsi/ipr.h
index cdb51960b53c..4dbeaafa0ba2 100644
--- a/drivers/scsi/ipr.h
+++ b/drivers/scsi/ipr.h
@@ -154,7 +154,9 @@
 #define IPR_DEFAULT_MAX_ERROR_DUMP                      984
 #define IPR_NUM_LOG_HCAMS                               2
 #define IPR_NUM_CFG_CHG_HCAMS                           2
+#define IPR_NUM_HCAM_QUEUE                              12
 #define IPR_NUM_HCAMS   (IPR_NUM_LOG_HCAMS + IPR_NUM_CFG_CHG_HCAMS)
+#define IPR_MAX_HCAMS   (IPR_NUM_HCAMS + IPR_NUM_HCAM_QUEUE)
 
 #define IPR_MAX_SIS64_TARGETS_PER_BUS                   1024
 #define IPR_MAX_SIS64_LUNS_PER_TARGET                   0xffffffff
@@ -1532,10 +1534,11 @@ struct ipr_ioa_cfg {
 
         char ipr_hcam_label[8];
 #define IPR_HCAM_LABEL                  "hcams"
-        struct ipr_hostrcb *hostrcb[IPR_NUM_HCAMS];
-        dma_addr_t hostrcb_dma[IPR_NUM_HCAMS];
+        struct ipr_hostrcb *hostrcb[IPR_MAX_HCAMS];
+        dma_addr_t hostrcb_dma[IPR_MAX_HCAMS];
         struct list_head hostrcb_free_q;
         struct list_head hostrcb_pending_q;
+        struct list_head hostrcb_report_q;
 
         struct ipr_hrr_queue hrrq[IPR_MAX_HRRQ_NUM];
         u32 hrrq_num;