cxlflash: Shutdown notify support for CXL Flash cards

Some CXL Flash cards need notification of device shutdown in order to
flush pending I/Os.

A PCI notification hook for shutdown has been added where the driver
notifies the card and returns. When the device is removed in the PCI
remove path, notification code will wait for shutdown processing to
complete.

Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index e027fa0fe430e278e289c5f8964daec65314e998..860008d4246679a4859ce9cf9b744651d01f2785 100644 (file)
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -764,6 +764,67 @@ static void term_afu(struct cxlflash_cfg *cfg)
        pr_debug("%s: returning\n", __func__);
 }
 
+/**
+ * notify_shutdown() - notifies device of pending shutdown
+ * @cfg:       Internal structure associated with the host.
+ * @wait:      Whether to wait for shutdown processing to complete.
+ *
+ * This function will notify the AFU that the adapter is being shutdown
+ * and will wait for shutdown processing to complete if wait is true.
+ * This notification should flush pending I/Os to the device and halt
+ * further I/Os until the next AFU reset is issued and device restarted.
+ */
+static void notify_shutdown(struct cxlflash_cfg *cfg, bool wait)
+{
+       struct afu *afu = cfg->afu;
+       struct device *dev = &cfg->dev->dev;
+       struct sisl_global_map __iomem *global = &afu->afu_map->global;
+       struct dev_dependent_vals *ddv;
+       u64 reg, status;
+       int i, retry_cnt = 0;
+
+       ddv = (struct dev_dependent_vals *)cfg->dev_id->driver_data;
+       if (!(ddv->flags & CXLFLASH_NOTIFY_SHUTDOWN))
+               return;
+
+       /* Notify AFU */
+       for (i = 0; i < NUM_FC_PORTS; i++) {
+               reg = readq_be(&global->fc_regs[i][FC_CONFIG2 / 8]);
+               reg |= SISL_FC_SHUTDOWN_NORMAL;
+               writeq_be(reg, &global->fc_regs[i][FC_CONFIG2 / 8]);
+       }
+
+       if (!wait)
+               return;
+
+       /* Wait up to 1.5 seconds for shutdown processing to complete */
+       for (i = 0; i < NUM_FC_PORTS; i++) {
+               retry_cnt = 0;
+               while (true) {
+                       status = readq_be(&global->fc_regs[i][FC_STATUS / 8]);
+                       if (status & SISL_STATUS_SHUTDOWN_COMPLETE)
+                               break;
+                       if (++retry_cnt >= MC_RETRY_CNT) {
+                               dev_dbg(dev, "%s: port %d shutdown processing "
+                                       "not yet completed\n", __func__, i);
+                               break;
+                       }
+                       msleep(100 * retry_cnt);
+               }
+       }
+}
+
+/**
+ * cxlflash_shutdown() - shutdown handler
+ * @pdev:      PCI device associated with the host.
+ */
+static void cxlflash_shutdown(struct pci_dev *pdev)
+{
+       struct cxlflash_cfg *cfg = pci_get_drvdata(pdev);
+
+       notify_shutdown(cfg, false);
+}
+
 /**
  * cxlflash_remove() - PCI entry point to tear down host
  * @pdev:      PCI device associated with the host.
@@ -785,6 +846,9 @@ static void cxlflash_remove(struct pci_dev *pdev)
                                                  cfg->tmf_slock);
        spin_unlock_irqrestore(&cfg->tmf_slock, lock_flags);
 
+       /* Notify AFU and wait for shutdown processing to complete */
+       notify_shutdown(cfg, true);
+
        cfg->state = STATE_FAILTERM;
        cxlflash_stop_term_user_contexts(cfg);
 
@@ -2336,7 +2400,7 @@ static struct scsi_host_template driver_template = {
 static struct dev_dependent_vals dev_corsa_vals = { CXLFLASH_MAX_SECTORS,
                                        0ULL };
 static struct dev_dependent_vals dev_flash_gt_vals = { CXLFLASH_MAX_SECTORS,
-                                       0ULL };
+                                       CXLFLASH_NOTIFY_SHUTDOWN };
 
 /*
  * PCI device binding table
@@ -2613,6 +2677,7 @@ static struct pci_driver cxlflash_driver = {
        .id_table = cxlflash_pci_table,
        .probe = cxlflash_probe,
        .remove = cxlflash_remove,
+       .shutdown = cxlflash_shutdown,
        .err_handler = &cxlflash_err_handler,
 };
 

diff --git a/drivers/scsi/cxlflash/main.h b/drivers/scsi/cxlflash/main.h
index 029f51743a24871f826cfa378e6b953d5e662db2..f54bbd5a606264c4bd4c5b1fe899008638c85c84 100644 (file)
--- a/drivers/scsi/cxlflash/main.h
+++ b/drivers/scsi/cxlflash/main.h
@@ -89,6 +89,7 @@ enum undo_level {
 struct dev_dependent_vals {
        u64 max_sectors;
        u64 flags;
+#define CXLFLASH_NOTIFY_SHUTDOWN   0x0000000000000001ULL
 };
 
 struct asyc_intr_info {

diff --git a/drivers/scsi/cxlflash/sislite.h b/drivers/scsi/cxlflash/sislite.h
index 0b3366f5e6f6c49601edf6ddc9d037bd75316965..347fc16719754e7a7db5db9a5f0f559ddb61f0bb 100644 (file)
--- a/drivers/scsi/cxlflash/sislite.h
+++ b/drivers/scsi/cxlflash/sislite.h
@@ -311,6 +311,12 @@ struct sisl_global_regs {
 #define SISL_FC_INTERNAL_MASK  ~(SISL_FC_INTERNAL_UNMASK)
 #define SISL_FC_INTERNAL_SHIFT 32
 
+#define SISL_FC_SHUTDOWN_NORMAL                0x0000000000000010ULL
+#define SISL_FC_SHUTDOWN_ABRUPT                0x0000000000000020ULL
+
+#define SISL_STATUS_SHUTDOWN_ACTIVE    0x0000000000000010ULL
+#define SISL_STATUS_SHUTDOWN_COMPLETE  0x0000000000000020ULL
+
 #define SISL_ASTATUS_UNMASK    0xFFFFULL               /* 1 means unmasked */
 #define SISL_ASTATUS_MASK      ~(SISL_ASTATUS_UNMASK)  /* 1 means masked */