megaraid_sas.c

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	int exception = 0;
	struct megasas_header *hdr = &cmd->frame->hdr;
	unsigned long flags;

	if (cmd->scmd) {
		cmd->scmd->SCp.ptr = (char *)0;
	}

	switch (hdr->cmd) {

	case MFI_CMD_PD_SCSI_IO:
	case MFI_CMD_LD_SCSI_IO:

		/*
		 * MFI_CMD_PD_SCSI_IO and MFI_CMD_LD_SCSI_IO could have been
		 * issued either through an IO path or an IOCTL path. If it
		 * was via IOCTL, we will send it to internal completion.
		 */
		if (cmd->sync_cmd) {
			cmd->sync_cmd = 0;
			megasas_complete_int_cmd(instance, cmd);
			break;
		}

	case MFI_CMD_LD_READ:
	case MFI_CMD_LD_WRITE:

		if (alt_status) {
			cmd->scmd->result = alt_status << 16;
			exception = 1;
		}

		if (exception) {

			spin_lock_irqsave(&instance->instance_lock, flags);
			instance->fw_outstanding--;
			spin_unlock_irqrestore(&instance->instance_lock, flags);

			megasas_unmap_sgbuf(instance, cmd);
			cmd->scmd->scsi_done(cmd->scmd);
			megasas_return_cmd(instance, cmd);

			break;
		}

		switch (hdr->cmd_status) {

		case MFI_STAT_OK:
			cmd->scmd->result = DID_OK << 16;
			break;

		case MFI_STAT_SCSI_IO_FAILED:
		case MFI_STAT_LD_INIT_IN_PROGRESS:
			cmd->scmd->result =
			    (DID_ERROR << 16) | hdr->scsi_status;
			break;

		case MFI_STAT_SCSI_DONE_WITH_ERROR:

			cmd->scmd->result = (DID_OK << 16) | hdr->scsi_status;

			if (hdr->scsi_status == SAM_STAT_CHECK_CONDITION) {
				memset(cmd->scmd->sense_buffer, 0,
				       SCSI_SENSE_BUFFERSIZE);
				memcpy(cmd->scmd->sense_buffer, cmd->sense,
				       hdr->sense_len);

				cmd->scmd->result |= DRIVER_SENSE << 24;
			}

			break;

		case MFI_STAT_LD_OFFLINE:
		case MFI_STAT_DEVICE_NOT_FOUND:
			cmd->scmd->result = DID_BAD_TARGET << 16;
			break;

		default:
			printk(KERN_DEBUG "megasas: MFI FW status %#x\n",
			       hdr->cmd_status);
			cmd->scmd->result = DID_ERROR << 16;
			break;
		}

		spin_lock_irqsave(&instance->instance_lock, flags);
		instance->fw_outstanding--;
		spin_unlock_irqrestore(&instance->instance_lock, flags);

		megasas_unmap_sgbuf(instance, cmd);
		cmd->scmd->scsi_done(cmd->scmd);
		megasas_return_cmd(instance, cmd);

		break;

	case MFI_CMD_SMP:
	case MFI_CMD_STP:
	case MFI_CMD_DCMD:

		/*
		 * See if got an event notification
		 */
		if (cmd->frame->dcmd.opcode == MR_DCMD_CTRL_EVENT_WAIT)
			megasas_service_aen(instance, cmd);
		else
			megasas_complete_int_cmd(instance, cmd);

		break;

	case MFI_CMD_ABORT:
		/*
		 * Cmd issued to abort another cmd returned
		 */
		megasas_complete_abort(instance, cmd);
		break;

	default:
		printk("megasas: Unknown command completed! [0x%X]\n",
		       hdr->cmd);
		break;
	}
}

/**
 * megasas_deplete_reply_queue -	Processes all completed commands
 * @instance:				Adapter soft state
 * @alt_status:				Alternate status to be returned to
 * 					SCSI mid-layer instead of the status
 * 					returned by the FW
 */
static int
megasas_deplete_reply_queue(struct megasas_instance *instance, u8 alt_status)
{
	u32 producer;
	u32 consumer;
	u32 context;
	struct megasas_cmd *cmd;

	/*
	 * Check if it is our interrupt
	 * Clear the interrupt 
	 */
	if(instance->instancet->clear_intr(instance->reg_set))
		return IRQ_NONE;

	producer = *instance->producer;
	consumer = *instance->consumer;

	while (consumer != producer) {
		context = instance->reply_queue[consumer];

		cmd = instance->cmd_list[context];

		megasas_complete_cmd(instance, cmd, alt_status);

		consumer++;
		if (consumer == (instance->max_fw_cmds + 1)) {
			consumer = 0;
		}
	}

	*instance->consumer = producer;

	return IRQ_HANDLED;
}

/**
 * megasas_isr - isr entry point
 */
static irqreturn_t megasas_isr(int irq, void *devp, struct pt_regs *regs)
{
	return megasas_deplete_reply_queue((struct megasas_instance *)devp,
					   DID_OK);
}

/**
 * megasas_transition_to_ready -	Move the FW to READY state
 * @instance:				Adapter soft state
 *
 * During the initialization, FW passes can potentially be in any one of
 * several possible states. If the FW in operational, waiting-for-handshake
 * states, driver must take steps to bring it to ready state. Otherwise, it
 * has to wait for the ready state.
 */
static int
megasas_transition_to_ready(struct megasas_instance* instance)
{
	int i;
	u8 max_wait;
	u32 fw_state;
	u32 cur_state;

	fw_state = instance->instancet->read_fw_status_reg(instance->reg_set) & MFI_STATE_MASK;

	while (fw_state != MFI_STATE_READY) {

		printk(KERN_INFO "megasas: Waiting for FW to come to ready"
		       " state\n");
		switch (fw_state) {

		case MFI_STATE_FAULT:

			printk(KERN_DEBUG "megasas: FW in FAULT state!!\n");
			return -ENODEV;

		case MFI_STATE_WAIT_HANDSHAKE:
			/*
			 * Set the CLR bit in inbound doorbell
			 */
			writel(MFI_INIT_CLEAR_HANDSHAKE,
				&instance->reg_set->inbound_doorbell);

			max_wait = 2;
			cur_state = MFI_STATE_WAIT_HANDSHAKE;
			break;

		case MFI_STATE_OPERATIONAL:
			/*
			 * Bring it to READY state; assuming max wait 2 secs
			 */
			megasas_disable_intr(instance->reg_set);
			writel(MFI_INIT_READY, &instance->reg_set->inbound_doorbell);

			max_wait = 10;
			cur_state = MFI_STATE_OPERATIONAL;
			break;

		case MFI_STATE_UNDEFINED:
			/*
			 * This state should not last for more than 2 seconds
			 */
			max_wait = 2;
			cur_state = MFI_STATE_UNDEFINED;
			break;

		case MFI_STATE_BB_INIT:
			max_wait = 2;
			cur_state = MFI_STATE_BB_INIT;
			break;

		case MFI_STATE_FW_INIT:
			max_wait = 20;
			cur_state = MFI_STATE_FW_INIT;
			break;

		case MFI_STATE_FW_INIT_2:
			max_wait = 20;
			cur_state = MFI_STATE_FW_INIT_2;
			break;

		case MFI_STATE_DEVICE_SCAN:
			max_wait = 20;
			cur_state = MFI_STATE_DEVICE_SCAN;
			break;

		case MFI_STATE_FLUSH_CACHE:
			max_wait = 20;
			cur_state = MFI_STATE_FLUSH_CACHE;
			break;

		default:
			printk(KERN_DEBUG "megasas: Unknown state 0x%x\n",
			       fw_state);
			return -ENODEV;
		}

		/*
		 * The cur_state should not last for more than max_wait secs
		 */
		for (i = 0; i < (max_wait * 1000); i++) {
			fw_state = instance->instancet->read_fw_status_reg(instance->reg_set) &  
					MFI_STATE_MASK ;

			if (fw_state == cur_state) {
				msleep(1);
			} else
				break;
		}

		/*
		 * Return error if fw_state hasn't changed after max_wait
		 */
		if (fw_state == cur_state) {
			printk(KERN_DEBUG "FW state [%d] hasn't changed "
			       "in %d secs\n", fw_state, max_wait);
			return -ENODEV;
		}
	};

	return 0;
}

/**
 * megasas_teardown_frame_pool -	Destroy the cmd frame DMA pool
 * @instance:				Adapter soft state
 */
static void megasas_teardown_frame_pool(struct megasas_instance *instance)
{
	int i;
	u32 max_cmd = instance->max_fw_cmds;
	struct megasas_cmd *cmd;

	if (!instance->frame_dma_pool)
		return;

	/*
	 * Return all frames to pool
	 */
	for (i = 0; i < max_cmd; i++) {

		cmd = instance->cmd_list[i];

		if (cmd->frame)
			pci_pool_free(instance->frame_dma_pool, cmd->frame,
				      cmd->frame_phys_addr);

		if (cmd->sense)
			pci_pool_free(instance->sense_dma_pool, cmd->frame,
				      cmd->sense_phys_addr);
	}

	/*
	 * Now destroy the pool itself
	 */
	pci_pool_destroy(instance->frame_dma_pool);
	pci_pool_destroy(instance->sense_dma_pool);

	instance->frame_dma_pool = NULL;
	instance->sense_dma_pool = NULL;
}

/**
 * megasas_create_frame_pool -	Creates DMA pool for cmd frames
 * @instance:			Adapter soft state
 *
 * Each command packet has an embedded DMA memory buffer that is used for
 * filling MFI frame and the SG list that immediately follows the frame. This
 * function creates those DMA memory buffers for each command packet by using
 * PCI pool facility.
 */
static int megasas_create_frame_pool(struct megasas_instance *instance)
{
	int i;
	u32 max_cmd;
	u32 sge_sz;
	u32 sgl_sz;
	u32 total_sz;
	u32 frame_count;
	struct megasas_cmd *cmd;

	max_cmd = instance->max_fw_cmds;

	/*
	 * Size of our frame is 64 bytes for MFI frame, followed by max SG
	 * elements and finally SCSI_SENSE_BUFFERSIZE bytes for sense buffer
	 */
	sge_sz = (IS_DMA64) ? sizeof(struct megasas_sge64) :
	    sizeof(struct megasas_sge32);

	/*
	 * Calculated the number of 64byte frames required for SGL
	 */
	sgl_sz = sge_sz * instance->max_num_sge;
	frame_count = (sgl_sz + MEGAMFI_FRAME_SIZE - 1) / MEGAMFI_FRAME_SIZE;

	/*
	 * We need one extra frame for the MFI command
	 */
	frame_count++;

	total_sz = MEGAMFI_FRAME_SIZE * frame_count;
	/*
	 * Use DMA pool facility provided by PCI layer
	 */
	instance->frame_dma_pool = pci_pool_create("megasas frame pool",
						   instance->pdev, total_sz, 64,
						   0);

	if (!instance->frame_dma_pool) {
		printk(KERN_DEBUG "megasas: failed to setup frame pool\n");
		return -ENOMEM;
	}

	instance->sense_dma_pool = pci_pool_create("megasas sense pool",
						   instance->pdev, 128, 4, 0);

	if (!instance->sense_dma_pool) {
		printk(KERN_DEBUG "megasas: failed to setup sense pool\n");

		pci_pool_destroy(instance->frame_dma_pool);
		instance->frame_dma_pool = NULL;

		return -ENOMEM;
	}

	/*
	 * Allocate and attach a frame to each of the commands in cmd_list.
	 * By making cmd->index as the context instead of the &cmd, we can
	 * always use 32bit context regardless of the architecture
	 */
	for (i = 0; i < max_cmd; i++) {

		cmd = instance->cmd_list[i];

		cmd->frame = pci_pool_alloc(instance->frame_dma_pool,
					    GFP_KERNEL, &cmd->frame_phys_addr);

		cmd->sense = pci_pool_alloc(instance->sense_dma_pool,
					    GFP_KERNEL, &cmd->sense_phys_addr);

		/*
		 * megasas_teardown_frame_pool() takes care of freeing
		 * whatever has been allocated
		 */
		if (!cmd->frame || !cmd->sense) {
			printk(KERN_DEBUG "megasas: pci_pool_alloc failed \n");
			megasas_teardown_frame_pool(instance);
			return -ENOMEM;
		}

		cmd->frame->io.context = cmd->index;
	}

	return 0;
}

/**
 * megasas_free_cmds -	Free all the cmds in the free cmd pool
 * @instance:		Adapter soft state
 */
static void megasas_free_cmds(struct megasas_instance *instance)
{
	int i;
	/* First free the MFI frame pool */
	megasas_teardown_frame_pool(instance);

	/* Free all the commands in the cmd_list */
	for (i = 0; i < instance->max_fw_cmds; i++)
		kfree(instance->cmd_list[i]);

	/* Free the cmd_list buffer itself */
	kfree(instance->cmd_list);
	instance->cmd_list = NULL;

	INIT_LIST_HEAD(&instance->cmd_pool);
}

/**
 * megasas_alloc_cmds -	Allocates the command packets
 * @instance:		Adapter soft state
 *
 * Each command that is issued to the FW, whether IO commands from the OS or
 * internal commands like IOCTLs, are wrapped in local data structure called
 * megasas_cmd. The frame embedded in this megasas_cmd is actually issued to
 * the FW.
 *
 * Each frame has a 32-bit field called context (tag). This context is used
 * to get back the megasas_cmd from the frame when a frame gets completed in
 * the ISR. Typically the address of the megasas_cmd itself would be used as
 * the context. But we wanted to keep the differences between 32 and 64 bit
 * systems to the mininum. We always use 32 bit integers for the context. In
 * this driver, the 32 bit values are the indices into an array cmd_list.
 * This array is used only to look up the megasas_cmd given the context. The
 * free commands themselves are maintained in a linked list called cmd_pool.
 */
static int megasas_alloc_cmds(struct megasas_instance *instance)
{
	int i;
	int j;
	u32 max_cmd;
	struct megasas_cmd *cmd;

	max_cmd = instance->max_fw_cmds;

	/*
	 * instance->cmd_list is an array of struct megasas_cmd pointers.
	 * Allocate the dynamic array first and then allocate individual
	 * commands.
	 */
	instance->cmd_list = kmalloc(sizeof(struct megasas_cmd *) * max_cmd,
				     GFP_KERNEL);

	if (!instance->cmd_list) {
		printk(KERN_DEBUG "megasas: out of memory\n");
		return -ENOMEM;
	}

	memset(instance->cmd_list, 0, sizeof(struct megasas_cmd *) * max_cmd);

	for (i = 0; i < max_cmd; i++) {
		instance->cmd_list[i] = kmalloc(sizeof(struct megasas_cmd),
						GFP_KERNEL);

		if (!instance->cmd_list[i]) {

			for (j = 0; j < i; j++)
				kfree(instance->cmd_list[j]);

			kfree(instance->cmd_list);
			instance->cmd_list = NULL;

			return -ENOMEM;
		}
	}

	/*
	 * Add all the commands to command pool (instance->cmd_pool)
	 */
	for (i = 0; i < max_cmd; i++) {
		cmd = instance->cmd_list[i];
		memset(cmd, 0, sizeof(struct megasas_cmd));
		cmd->index = i;
		cmd->instance = instance;

		list_add_tail(&cmd->list, &instance->cmd_pool);
	}

	/*
	 * Create a frame pool and assign one frame to each cmd
	 */
	if (megasas_create_frame_pool(instance)) {
		printk(KERN_DEBUG "megasas: Error creating frame DMA pool\n");
		megasas_free_cmds(instance);
	}

	return 0;