scsi: lpfc: Adding ability to reset chip via pci bus reset

This patch adds a "pci_bus_reset" option to the board_mode sysfs attribute.
This option uses the pci_reset_bus() api to reset the PCIe link the adapter
is on, which will reset the chip/adapter.  Prior to issuing this option,
all functions on the same chip must be placed in the offline state by the
admin. After the reset, all of the instances may be brought online again.

The primary purpose of this functionality is to support cases where
firmware update required a chip reset but the admin did not want to reboot
the machine in order to instantiate the firmware update.

Sanity checks take place prior to the reset to ensure the adapter is the
sole entity on the PCIe bus and that all functions are in the offline
state.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

5 files changed, 233 insertions, 27 deletions

diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index 513ac1be861f..4bae72cbf3f6 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -1192,6 +1192,82 @@ out:
 }
 
 /**
+ * lpfc_reset_pci_bus - resets PCI bridge controller's secondary bus of an HBA
+ * @phba: lpfc_hba pointer.
+ *
+ * Description:
+ * Issues a PCI secondary bus reset for the phba->pcidev.
+ *
+ * Notes:
+ * First walks the bus_list to ensure only PCI devices with Emulex
+ * vendor id, device ids that support hot reset, only one occurrence
+ * of function 0, and all ports on the bus are in offline mode to ensure the
+ * hot reset only affects one valid HBA.
+ *
+ * Returns:
+ * -ENOTSUPP, cfg_enable_hba_reset must be of value 2
+ * -ENODEV,   NULL ptr to pcidev
+ * -EBADSLT,  detected invalid device
+ * -EBUSY,    port is not in offline state
+ *      0,    successful
+ */
+int
+lpfc_reset_pci_bus(struct lpfc_hba *phba)
+{
+	struct pci_dev *pdev = phba->pcidev;
+	struct Scsi_Host *shost = NULL;
+	struct lpfc_hba *phba_other = NULL;
+	struct pci_dev *ptr = NULL;
+	int res;
+
+	if (phba->cfg_enable_hba_reset != 2)
+		return -ENOTSUPP;
+
+	if (!pdev) {
+		lpfc_printf_log(phba, KERN_INFO, LOG_INIT, "8345 pdev NULL!\n");
+		return -ENODEV;
+	}
+
+	res = lpfc_check_pci_resettable(phba);
+	if (res)
+		return res;
+
+	/* Walk the list of devices on the pci_dev's bus */
+	list_for_each_entry(ptr, &pdev->bus->devices, bus_list) {
+		/* Check port is offline */
+		shost = pci_get_drvdata(ptr);
+		if (shost) {
+			phba_other =
+				((struct lpfc_vport *)shost->hostdata)->phba;
+			if (!(phba_other->pport->fc_flag & FC_OFFLINE_MODE)) {
+				lpfc_printf_log(phba_other, KERN_INFO, LOG_INIT,
+						"8349 WWPN = 0x%02x%02x%02x%02x"
+						"%02x%02x%02x%02x is not "
+						"offline!\n",
+						phba_other->wwpn[0],
+						phba_other->wwpn[1],
+						phba_other->wwpn[2],
+						phba_other->wwpn[3],
+						phba_other->wwpn[4],
+						phba_other->wwpn[5],
+						phba_other->wwpn[6],
+						phba_other->wwpn[7]);
+				return -EBUSY;
+			}
+		}
+	}
+
+	/* Issue PCI bus reset */
+	res = pci_reset_bus(pdev);
+	if (res) {
+		lpfc_printf_log(phba, KERN_ERR, LOG_INIT,
+				"8350 PCI reset bus failed: %d\n", res);
+	}
+
+	return res;
+}
+
+/**
  * lpfc_selective_reset - Offline then onlines the port
  * @phba: lpfc_hba pointer.
  *
@@ -1618,6 +1694,9 @@ lpfc_board_mode_store(struct device *dev, struct device_attribute *attr,
 		status = lpfc_sli4_pdev_reg_request(phba, LPFC_FW_RESET);
 	else if (strncmp(buf, "dv_reset", sizeof("dv_reset") - 1) == 0)
 		status = lpfc_sli4_pdev_reg_request(phba, LPFC_DV_RESET);
+	else if (strncmp(buf, "pci_bus_reset", sizeof("pci_bus_reset") - 1)
+		 == 0)
+		status = lpfc_reset_pci_bus(phba);
 	else if (strncmp(buf, "trunk", sizeof("trunk") - 1) == 0)
 		status = lpfc_set_trunking(phba, (char *)buf + sizeof("trunk"));
 	else
@@ -5376,9 +5455,10 @@ LPFC_ATTR_R(nvme_io_channel,
 # lpfc_enable_hba_reset: Allow or prevent HBA resets to the hardware.
 #       0  = HBA resets disabled
 #       1  = HBA resets enabled (default)
-# Value range is [0,1]. Default value is 1.
+#       2  = HBA reset via PCI bus reset enabled
+# Value range is [0,2]. Default value is 1.
 */
-LPFC_ATTR_R(enable_hba_reset, 1, 0, 1, "Enable HBA resets from the driver.");
+LPFC_ATTR_RW(enable_hba_reset, 1, 0, 2, "Enable HBA resets from the driver.");
 
 /*
 # lpfc_enable_hba_heartbeat: Disable HBA heartbeat timer..
diff --git a/drivers/scsi/lpfc/lpfc_crtn.h b/drivers/scsi/lpfc/lpfc_crtn.h
index 6a8c5b804c2d..39f3fa988732 100644
--- a/drivers/scsi/lpfc/lpfc_crtn.h
+++ b/drivers/scsi/lpfc/lpfc_crtn.h
@@ -383,6 +383,7 @@ void lpfc_rq_buf_free(struct lpfc_hba *phba, struct lpfc_dmabuf *mp);
 int lpfc_link_reset(struct lpfc_vport *vport);
 
 /* Function prototypes. */
+int lpfc_check_pci_resettable(const struct lpfc_hba *phba);
 const char* lpfc_info(struct Scsi_Host *);
 int lpfc_scan_finished(struct Scsi_Host *, unsigned long);
 
diff --git a/drivers/scsi/lpfc/lpfc_hw4.h b/drivers/scsi/lpfc/lpfc_hw4.h
index 4e7fa3c44eee..c15b9b6fb840 100644
--- a/drivers/scsi/lpfc/lpfc_hw4.h
+++ b/drivers/scsi/lpfc/lpfc_hw4.h
@@ -3850,6 +3850,9 @@ struct lpfc_mbx_wr_object {
 #define lpfc_wr_object_eof_SHIFT		31
 #define lpfc_wr_object_eof_MASK			0x00000001
 #define lpfc_wr_object_eof_WORD			word4
+#define lpfc_wr_object_eas_SHIFT		29
+#define lpfc_wr_object_eas_MASK			0x00000001
+#define lpfc_wr_object_eas_WORD			word4
 #define lpfc_wr_object_write_length_SHIFT	0
 #define lpfc_wr_object_write_length_MASK	0x00FFFFFF
 #define lpfc_wr_object_write_length_WORD	word4
@@ -3860,6 +3863,15 @@ struct lpfc_mbx_wr_object {
 		} request;
 		struct {
 			uint32_t actual_write_length;
+			uint32_t word5;
+#define lpfc_wr_object_change_status_SHIFT	0
+#define lpfc_wr_object_change_status_MASK	0x000000FF
+#define lpfc_wr_object_change_status_WORD	word5
+#define LPFC_CHANGE_STATUS_NO_RESET_NEEDED	0x00
+#define LPFC_CHANGE_STATUS_PHYS_DEV_RESET	0x01
+#define LPFC_CHANGE_STATUS_FW_RESET		0x02
+#define LPFC_CHANGE_STATUS_PORT_MIGRATION	0x04
+#define LPFC_CHANGE_STATUS_PCI_RESET		0x05
 		} response;
 	} u;
 };
diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index 473d255f15c0..f61de71ff713 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -4460,6 +4460,66 @@ lpfc_tskmgmt_def_cmpl(struct lpfc_hba *phba,
 }
 
 /**
+ * lpfc_check_pci_resettable - Walks list of devices on pci_dev's bus to check
+ *                             if issuing a pci_bus_reset is possibly unsafe
+ * @phba: lpfc_hba pointer.
+ *
+ * Description:
+ * Walks the bus_list to ensure only PCI devices with Emulex
+ * vendor id, device ids that support hot reset, and only one occurrence
+ * of function 0.
+ *
+ * Returns:
+ * -EBADSLT,  detected invalid device
+ *      0,    successful
+ */
+int
+lpfc_check_pci_resettable(const struct lpfc_hba *phba)
+{
+	const struct pci_dev *pdev = phba->pcidev;
+	struct pci_dev *ptr = NULL;
+	u8 counter = 0;
+
+	/* Walk the list of devices on the pci_dev's bus */
+	list_for_each_entry(ptr, &pdev->bus->devices, bus_list) {
+		/* Check for Emulex Vendor ID */
+		if (ptr->vendor != PCI_VENDOR_ID_EMULEX) {
+			lpfc_printf_log(phba, KERN_INFO, LOG_INIT,
+					"8346 Non-Emulex vendor found: "
+					"0x%04x\n", ptr->vendor);
+			return -EBADSLT;
+		}
+
+		/* Check for valid Emulex Device ID */
+		switch (ptr->device) {
+		case PCI_DEVICE_ID_LANCER_FC:
+		case PCI_DEVICE_ID_LANCER_G6_FC:
+		case PCI_DEVICE_ID_LANCER_G7_FC:
+			break;
+		default:
+			lpfc_printf_log(phba, KERN_INFO, LOG_INIT,
+					"8347 Invalid device found: "
+					"0x%04x\n", ptr->device);
+			return -EBADSLT;
+		}
+
+		/* Check for only one function 0 ID to ensure only one HBA on
+		 * secondary bus
+		 */
+		if (ptr->devfn == 0) {
+			if (++counter > 1) {
+				lpfc_printf_log(phba, KERN_INFO, LOG_INIT,
+						"8348 More than one device on "
+						"secondary bus found\n");
+				return -EBADSLT;
+			}
+		}
+	}
+
+	return 0;
+}
+
+/**
  * lpfc_info - Info entry point of scsi_host_template data structure
  * @host: The scsi host for which this call is being executed.
  *
@@ -4473,32 +4533,53 @@ lpfc_info(struct Scsi_Host *host)
 {
 	struct lpfc_vport *vport = (struct lpfc_vport *) host->hostdata;
 	struct lpfc_hba   *phba = vport->phba;
-	int len, link_speed = 0;
-	static char  lpfcinfobuf[384];
+	int link_speed = 0;
+	static char lpfcinfobuf[384];
+	char tmp[384] = {0};
 
-	memset(lpfcinfobuf,0,384);
+	memset(lpfcinfobuf, 0, sizeof(lpfcinfobuf));
 	if (phba && phba->pcidev){
-		strncpy(lpfcinfobuf, phba->ModelDesc, 256);
-		len = strlen(lpfcinfobuf);
-		snprintf(lpfcinfobuf + len,
-			384-len,
-			" on PCI bus %02x device %02x irq %d",
-			phba->pcidev->bus->number,
-			phba->pcidev->devfn,
-			phba->pcidev->irq);
-		len = strlen(lpfcinfobuf);
+		/* Model Description */
+		scnprintf(tmp, sizeof(tmp), phba->ModelDesc);
+		if (strlcat(lpfcinfobuf, tmp, sizeof(lpfcinfobuf)) >=
+		    sizeof(lpfcinfobuf))
+			goto buffer_done;
+
+		/* PCI Info */
+		scnprintf(tmp, sizeof(tmp),
+			  " on PCI bus %02x device %02x irq %d",
+			  phba->pcidev->bus->number, phba->pcidev->devfn,
+			  phba->pcidev->irq);
+		if (strlcat(lpfcinfobuf, tmp, sizeof(lpfcinfobuf)) >=
+		    sizeof(lpfcinfobuf))
+			goto buffer_done;
+
+		/* Port Number */
 		if (phba->Port[0]) {
-			snprintf(lpfcinfobuf + len,
-				 384-len,
-				 " port %s",
-				 phba->Port);
+			scnprintf(tmp, sizeof(tmp), " port %s", phba->Port);
+			if (strlcat(lpfcinfobuf, tmp, sizeof(lpfcinfobuf)) >=
+			    sizeof(lpfcinfobuf))
+				goto buffer_done;
 		}
-		len = strlen(lpfcinfobuf);
+
+		/* Link Speed */
 		link_speed = lpfc_sli_port_speed_get(phba);
-		if (link_speed != 0)
-			snprintf(lpfcinfobuf + len, 384-len,
-				 " Logical Link Speed: %d Mbps", link_speed);
+		if (link_speed != 0) {
+			scnprintf(tmp, sizeof(tmp),
+				  " Logical Link Speed: %d Mbps", link_speed);
+			if (strlcat(lpfcinfobuf, tmp, sizeof(lpfcinfobuf)) >=
+			    sizeof(lpfcinfobuf))
+				goto buffer_done;
+		}
+
+		/* PCI resettable */
+		if (!lpfc_check_pci_resettable(phba)) {
+			scnprintf(tmp, sizeof(tmp), " PCI resettable");
+			strlcat(lpfcinfobuf, tmp, sizeof(lpfcinfobuf));
+		}
 	}
+
+buffer_done:
 	return lpfcinfobuf;
 }
 
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index f3cb6b4c52ff..766722e993c2 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -19264,11 +19264,11 @@ lpfc_wr_object(struct lpfc_hba *phba, struct list_head *dmabuf_list,
 	struct lpfc_mbx_wr_object *wr_object;
 	LPFC_MBOXQ_t *mbox;
 	int rc = 0, i = 0;
-	uint32_t shdr_status, shdr_add_status;
+	uint32_t shdr_status, shdr_add_status, shdr_change_status;
 	uint32_t mbox_tmo;
-	union lpfc_sli4_cfg_shdr *shdr;
 	struct lpfc_dmabuf *dmabuf;
 	uint32_t written = 0;
+	bool check_change_status = false;
 
 	mbox = mempool_alloc(phba->mbox_mem_pool, GFP_KERNEL);
 	if (!mbox)
@@ -19296,6 +19296,8 @@ lpfc_wr_object(struct lpfc_hba *phba, struct list_head *dmabuf_list,
 				(size - written);
 			written += (size - written);
 			bf_set(lpfc_wr_object_eof, &wr_object->u.request, 1);
+			bf_set(lpfc_wr_object_eas, &wr_object->u.request, 1);
+			check_change_status = true;
 		} else {
 			wr_object->u.request.bde[i].tus.f.bdeSize =
 				SLI4_PAGE_SIZE;
@@ -19312,9 +19314,39 @@ lpfc_wr_object(struct lpfc_hba *phba, struct list_head *dmabuf_list,
 		rc = lpfc_sli_issue_mbox_wait(phba, mbox, mbox_tmo);
 	}
 	/* The IOCTL status is embedded in the mailbox subheader. */
-	shdr = (union lpfc_sli4_cfg_shdr *) &wr_object->header.cfg_shdr;
-	shdr_status = bf_get(lpfc_mbox_hdr_status, &shdr->response);
-	shdr_add_status = bf_get(lpfc_mbox_hdr_add_status, &shdr->response);
+	shdr_status = bf_get(lpfc_mbox_hdr_status,
+			     &wr_object->header.cfg_shdr.response);
+	shdr_add_status = bf_get(lpfc_mbox_hdr_add_status,
+				 &wr_object->header.cfg_shdr.response);
+	if (check_change_status) {
+		shdr_change_status = bf_get(lpfc_wr_object_change_status,
+					    &wr_object->u.response);
+		switch (shdr_change_status) {
+		case (LPFC_CHANGE_STATUS_PHYS_DEV_RESET):
+			lpfc_printf_log(phba, KERN_INFO, LOG_INIT,
+					"3198 Firmware write complete: System "
+					"reboot required to instantiate\n");
+			break;
+		case (LPFC_CHANGE_STATUS_FW_RESET):
+			lpfc_printf_log(phba, KERN_INFO, LOG_INIT,
+					"3199 Firmware write complete: Firmware"
+					" reset required to instantiate\n");
+			break;
+		case (LPFC_CHANGE_STATUS_PORT_MIGRATION):
+			lpfc_printf_log(phba, KERN_INFO, LOG_INIT,
+					"3200 Firmware write complete: Port "
+					"Migration or PCI Reset required to "
+					"instantiate\n");
+			break;
+		case (LPFC_CHANGE_STATUS_PCI_RESET):
+			lpfc_printf_log(phba, KERN_INFO, LOG_INIT,
+					"3201 Firmware write complete: PCI "
+					"Reset required to instantiate\n");
+			break;
+		default:
+			break;
+		}
+	}
 	if (rc != MBX_TIMEOUT)
 		mempool_free(mbox, phba->mbox_mem_pool);
 	if (shdr_status || shdr_add_status || rc) {