megaraid_sas : Firmware crash dump feature support

Resending the patch. Addressed the review comments from Tomas Henzl.
Move buff_offset inside spinlock, corrected loop at crash dump buffer free,
reset_devices check is added to disable fw crash dump feature in kdump kernel.

This feature will provide similar interface as kernel crash dump feature.
When megaraid firmware encounter any crash, driver will collect the firmware raw image and
dump it into pre-configured location.

Driver will allocate two different segment of memory.
#1 Non-DMA able large buffer (will be allocated on demand) to capture actual FW crash dump.
#2 DMA buffer (persistence allocation) just to do a arbitrator job.

Firmware will keep writing Crash dump data in chucks of DMA buffer size into #2,
which will be copy back by driver to the host memory as described in #1.

Driver-Firmware interface:
==================
A.) Host driver can allocate maximum 512MB Host memory to store crash dump data.

This memory will be internal to the host and will not be exposed to the Firmware.
Driver may not be able to allocate 512 MB. In that case, driver will do possible memory
(available at run time) allocation to store crash dump data.

Let’s call this buffer as Host Crash Buffer.

Host Crash buffer will not be contigious as a whole, but it will have multiple chunk of contigious memory.
This will be internal to driver and firmware/application are unaware of it.
Partial allocation of Host Crash buffer may have valid information to debug depending upon
what was collected in that buffer and depending on nature of failure.

Complete Crash dump is the best case, but we do want to capture partial buffer just to grab something rather than nothing.
Host Crash buffer will be allocated only when FW Crash dump data is available,
and will be deallocated once application copy Host Crash buffer to the file.
Host Crash buffer size can be anything between 1MB to 512MB. (It will be multiple of 1MBs)

B.) Irrespective of underlying Firmware capability of crash dump support,
driver will allocate DMA buffer at start of the day for each MR controllers.
Let’s call this buffer as “DMA Crash Buffer”.

For this feature, size of DMA crash buffer will be 1MB.
(We will not gain much even if DMA buffer size is increased.)

C.) Driver will now read Controller Info sending existing dcmd “MR_DCMD_CTRL_GET_INFO”.
Driver should extract the information from ctrl info provided by firmware and
figure out if firmware support crash dump feature or not.

Driver will enable crash dump feature only if
“Firmware support Crash dump” +
“Driver was able to create DMA Crash Buffer”.

If either one from above is not set, Crash dump feature should be disable in driver.
Firmware will enable crash dump feature only if “Driver Send DCMD- MR_DCMD_SET_CRASH_BUF_PARA with MR_CRASH_BUF_TURN_ON”

Helper application/script should use sysfs parameter fw_crash_xxx to actually copy data from
host memory to the filesystem.

Signed-off-by: Sumit Saxena <sumit.saxena@avagotech.com>
Signed-off-by: Kashyap Desai <kashyap.desai@avagotech.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 170 insertions, 2 deletions

diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c
index 155b8b1a8f4b..913e9fa8fc15 100644
--- a/drivers/scsi/megaraid/megaraid_sas_fusion.c
+++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c
@@ -91,6 +91,8 @@ void megasas_start_timer(struct megasas_instance *instance,
 extern struct megasas_mgmt_info megasas_mgmt_info;
 extern int resetwaittime;
 
+
+
 /**
  * megasas_enable_intr_fusion -	Enables interrupts
  * @regs:			MFI register set
@@ -2055,7 +2057,7 @@ irqreturn_t megasas_isr_fusion(int irq, void *devp)
 {
 	struct megasas_irq_context *irq_context = devp;
 	struct megasas_instance *instance = irq_context->instance;
-	u32 mfiStatus, fw_state;
+	u32 mfiStatus, fw_state, dma_state;
 
 	if (instance->mask_interrupts)
 		return IRQ_NONE;
@@ -2077,7 +2079,16 @@ irqreturn_t megasas_isr_fusion(int irq, void *devp)
 		/* If we didn't complete any commands, check for FW fault */
 		fw_state = instance->instancet->read_fw_status_reg(
 			instance->reg_set) & MFI_STATE_MASK;
-		if (fw_state == MFI_STATE_FAULT) {
+		dma_state = instance->instancet->read_fw_status_reg
+			(instance->reg_set) & MFI_STATE_DMADONE;
+		if (instance->crash_dump_drv_support &&
+			instance->crash_dump_app_support) {
+			/* Start collecting crash, if DMA bit is done */
+			if ((fw_state == MFI_STATE_FAULT) && dma_state)
+				schedule_work(&instance->crash_init);
+			else if (fw_state == MFI_STATE_FAULT)
+				schedule_work(&instance->work_init);
+		} else if (fw_state == MFI_STATE_FAULT) {
 			printk(KERN_WARNING "megaraid_sas: Iop2SysDoorbellInt"
 			       "for scsi%d\n", instance->host->host_no);
 			schedule_work(&instance->work_init);
@@ -2230,6 +2241,49 @@ megasas_read_fw_status_reg_fusion(struct megasas_register_set __iomem *regs)
 }
 
 /**
+ * megasas_alloc_host_crash_buffer -	Host buffers for Crash dump collection from Firmware
+ * @instance:				Controller's soft instance
+ * return:			        Number of allocated host crash buffers
+ */
+static void
+megasas_alloc_host_crash_buffer(struct megasas_instance *instance)
+{
+	unsigned int i;
+
+	instance->crash_buf_pages = get_order(CRASH_DMA_BUF_SIZE);
+	for (i = 0; i < MAX_CRASH_DUMP_SIZE; i++) {
+		instance->crash_buf[i] = (void	*)__get_free_pages(GFP_KERNEL,
+				instance->crash_buf_pages);
+		if (!instance->crash_buf[i]) {
+			dev_info(&instance->pdev->dev, "Firmware crash dump "
+				"memory allocation failed at index %d\n", i);
+			break;
+		}
+	}
+	instance->drv_buf_alloc = i;
+}
+
+/**
+ * megasas_free_host_crash_buffer -	Host buffers for Crash dump collection from Firmware
+ * @instance:				Controller's soft instance
+ */
+void
+megasas_free_host_crash_buffer(struct megasas_instance *instance)
+{
+	unsigned int i
+;
+	for (i = 0; i < instance->drv_buf_alloc; i++) {
+		if (instance->crash_buf[i])
+			free_pages((ulong)instance->crash_buf[i],
+					instance->crash_buf_pages);
+	}
+	instance->drv_buf_index = 0;
+	instance->drv_buf_alloc = 0;
+	instance->fw_crash_state = UNAVAILABLE;
+	instance->fw_crash_buffer_size = 0;
+}
+
+/**
  * megasas_adp_reset_fusion -	For controller reset
  * @regs:				MFI register set
  */
@@ -2372,6 +2426,7 @@ int megasas_reset_fusion(struct Scsi_Host *shost, int iotimeout)
 	struct megasas_cmd *cmd_mfi;
 	union MEGASAS_REQUEST_DESCRIPTOR_UNION *req_desc;
 	u32 host_diag, abs_state, status_reg, reset_adapter;
+	u32 io_timeout_in_crash_mode = 0;
 
 	instance = (struct megasas_instance *)shost->hostdata;
 	fusion = instance->ctrl_context;
@@ -2385,6 +2440,42 @@ int megasas_reset_fusion(struct Scsi_Host *shost, int iotimeout)
 		mutex_unlock(&instance->reset_mutex);
 		return FAILED;
 	}
+	status_reg = instance->instancet->read_fw_status_reg(instance->reg_set);
+	abs_state = status_reg & MFI_STATE_MASK;
+
+	/* IO timeout detected, forcibly put FW in FAULT state */
+	if (abs_state != MFI_STATE_FAULT && instance->crash_dump_buf &&
+		instance->crash_dump_app_support && iotimeout) {
+		dev_info(&instance->pdev->dev, "IO timeout is detected, "
+			"forcibly FAULT Firmware\n");
+		instance->adprecovery = MEGASAS_ADPRESET_SM_INFAULT;
+		status_reg = readl(&instance->reg_set->doorbell);
+		writel(status_reg | MFI_STATE_FORCE_OCR,
+			&instance->reg_set->doorbell);
+		readl(&instance->reg_set->doorbell);
+		mutex_unlock(&instance->reset_mutex);
+		do {
+			ssleep(3);
+			io_timeout_in_crash_mode++;
+			dev_dbg(&instance->pdev->dev, "waiting for [%d] "
+				"seconds for crash dump collection and OCR "
+				"to be done\n", (io_timeout_in_crash_mode * 3));
+		} while ((instance->adprecovery != MEGASAS_HBA_OPERATIONAL) &&
+			(io_timeout_in_crash_mode < 80));
+
+		if (instance->adprecovery == MEGASAS_HBA_OPERATIONAL) {
+			dev_info(&instance->pdev->dev, "OCR done for IO "
+				"timeout case\n");
+			retval = SUCCESS;
+		} else {
+			dev_info(&instance->pdev->dev, "Controller is not "
+				"operational after 240 seconds wait for IO "
+				"timeout case in FW crash dump mode\n do "
+				"OCR/kill adapter\n");
+			retval = megasas_reset_fusion(shost, 0);
+		}
+		return retval;
+	}
 
 	if (instance->requestorId && !instance->skip_heartbeat_timer_del)
 		del_timer_sync(&instance->sriov_heartbeat_timer);
@@ -2651,6 +2742,15 @@ int megasas_reset_fusion(struct Scsi_Host *shost, int iotimeout)
 			printk(KERN_WARNING "megaraid_sas: Reset "
 			       "successful for scsi%d.\n",
 				instance->host->host_no);
+
+			if (instance->crash_dump_drv_support) {
+				if (instance->crash_dump_app_support)
+					megasas_set_crash_dump_params(instance,
+						MR_CRASH_BUF_TURN_ON);
+				else
+					megasas_set_crash_dump_params(instance,
+						MR_CRASH_BUF_TURN_OFF);
+			}
 			retval = SUCCESS;
 			goto out;
 		}
@@ -2679,6 +2779,74 @@ out:
 	return retval;
 }
 
+/* Fusion Crash dump collection work queue */
+void  megasas_fusion_crash_dump_wq(struct work_struct *work)
+{
+	struct megasas_instance *instance =
+		container_of(work, struct megasas_instance, crash_init);
+	u32 status_reg;
+	u8 partial_copy = 0;
+
+
+	status_reg = instance->instancet->read_fw_status_reg(instance->reg_set);
+
+	/*
+	 * Allocate host crash buffers to copy data from 1 MB DMA crash buffer
+	 * to host crash buffers
+	 */
+	if (instance->drv_buf_index == 0) {
+		/* Buffer is already allocated for old Crash dump.
+		 * Do OCR and do not wait for crash dump collection
+		 */
+		if (instance->drv_buf_alloc) {
+			dev_info(&instance->pdev->dev, "earlier crash dump is "
+				"not yet copied by application, ignoring this "
+				"crash dump and initiating OCR\n");
+			status_reg |= MFI_STATE_CRASH_DUMP_DONE;
+			writel(status_reg,
+				&instance->reg_set->outbound_scratch_pad);
+			readl(&instance->reg_set->outbound_scratch_pad);
+			return;
+		}
+		megasas_alloc_host_crash_buffer(instance);
+		dev_info(&instance->pdev->dev, "Number of host crash buffers "
+			"allocated: %d\n", instance->drv_buf_alloc);
+	}
+
+	/*
+	 * Driver has allocated max buffers, which can be allocated
+	 * and FW has more crash dump data, then driver will
+	 * ignore the data.
+	 */
+	if (instance->drv_buf_index >= (instance->drv_buf_alloc)) {
+		dev_info(&instance->pdev->dev, "Driver is done copying "
+			"the buffer: %d\n", instance->drv_buf_alloc);
+		status_reg |= MFI_STATE_CRASH_DUMP_DONE;
+		partial_copy = 1;
+	} else {
+		memcpy(instance->crash_buf[instance->drv_buf_index],
+			instance->crash_dump_buf, CRASH_DMA_BUF_SIZE);
+		instance->drv_buf_index++;
+		status_reg &= ~MFI_STATE_DMADONE;
+	}
+
+	if (status_reg & MFI_STATE_CRASH_DUMP_DONE) {
+		dev_info(&instance->pdev->dev, "Crash Dump is available,number "
+			"of copied buffers: %d\n", instance->drv_buf_index);
+		instance->fw_crash_buffer_size =  instance->drv_buf_index;
+		instance->fw_crash_state = AVAILABLE;
+		instance->drv_buf_index = 0;
+		writel(status_reg, &instance->reg_set->outbound_scratch_pad);
+		readl(&instance->reg_set->outbound_scratch_pad);
+		if (!partial_copy)
+			megasas_reset_fusion(instance->host, 0);
+	} else {
+		writel(status_reg, &instance->reg_set->outbound_scratch_pad);
+		readl(&instance->reg_set->outbound_scratch_pad);
+	}
+}
+
+
 /* Fusion OCR work queue */
 void megasas_fusion_ocr_wq(struct work_struct *work)
 {