drivers/scsi/ibmvscsi/rpa_vscsi.c - third_party/linux - Git at Google

 /* ------------------------------------------------------------
  * rpa_vscsi.c
  * (C) Copyright IBM Corporation 1994, 2003
  * Authors: Colin DeVilbiss (devilbis@us.ibm.com)
  *          Santiago Leon (santil@us.ibm.com)
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
  * USA
  *
  * ------------------------------------------------------------
  * RPA-specific functions of the SCSI host adapter for Virtual I/O devices
  *
  * This driver allows the Linux SCSI peripheral drivers to directly
  * access devices in the hosting partition, either on an iSeries
  * hypervisor system or a converged hypervisor system.
  */

 #include <asm/vio.h>
 #include <asm/prom.h>
 #include <asm/iommu.h>
 #include <asm/hvcall.h>
 #include <linux/dma-mapping.h>
 #include <linux/interrupt.h>
 #include "ibmvscsi.h"

 static char partition_name[97] = "UNKNOWN";
 static unsigned int partition_number = -1;

 /* ------------------------------------------------------------
  * Routines for managing the command/response queue
  */
 /**
  * ibmvscsi_handle_event: - Interrupt handler for crq events
  * @irq:	number of irq to handle, not used
  * @dev_instance: ibmvscsi_host_data of host that received interrupt
  * @regs:	pt_regs with registers
  *
  * Disables interrupts and schedules srp_task
  * Always returns IRQ_HANDLED
  */
 static irqreturn_t ibmvscsi_handle_event(int irq,
 					 void *dev_instance,
 					 struct pt_regs *regs)
 {
 	struct ibmvscsi_host_data *hostdata =
 	    (struct ibmvscsi_host_data *)dev_instance;
 	vio_disable_interrupts(to_vio_dev(hostdata->dev));
 	tasklet_schedule(&hostdata->srp_task);
 	return IRQ_HANDLED;
 }

 /**
  * release_crq_queue: - Deallocates data and unregisters CRQ
  * @queue:	crq_queue to initialize and register
  * @host_data:	ibmvscsi_host_data of host
  *
  * Frees irq, deallocates a page for messages, unmaps dma, and unregisters
  * the crq with the hypervisor.
  */
 void ibmvscsi_release_crq_queue(struct crq_queue *queue,
 				struct ibmvscsi_host_data *hostdata,
 				int max_requests)
 {
 	long rc;
 	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 	free_irq(vdev->irq, (void *)hostdata);
 	tasklet_kill(&hostdata->srp_task);
 	do {
 		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
 	dma_unmap_single(hostdata->dev,
 			 queue->msg_token,
 			 queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
 	free_page((unsigned long)queue->msgs);
 }

 /**
  * crq_queue_next_crq: - Returns the next entry in message queue
  * @queue:	crq_queue to use
  *
  * Returns pointer to next entry in queue, or NULL if there are no new
  * entried in the CRQ.
  */
 static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
 {
 	struct viosrp_crq *crq;
 	unsigned long flags;

 	spin_lock_irqsave(&queue->lock, flags);
 	crq = &queue->msgs[queue->cur];
 	if (crq->valid & 0x80) {
 		if (++queue->cur == queue->size)
 			queue->cur = 0;
 	} else
 		crq = NULL;
 	spin_unlock_irqrestore(&queue->lock, flags);

 	return crq;
 }

 /**
  * ibmvscsi_send_crq: - Send a CRQ
  * @hostdata:	the adapter
  * @word1:	the first 64 bits of the data
  * @word2:	the second 64 bits of the data
  */
 int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata, u64 word1, u64 word2)
 {
 	struct vio_dev *vdev = to_vio_dev(hostdata->dev);

 	return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
 }

 /**
  * ibmvscsi_task: - Process srps asynchronously
  * @data:	ibmvscsi_host_data of host
  */
 static void ibmvscsi_task(void *data)
 {
 	struct ibmvscsi_host_data *hostdata = (struct ibmvscsi_host_data *)data;
 	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 	struct viosrp_crq *crq;
 	int done = 0;

 	while (!done) {
 		/* Pull all the valid messages off the CRQ */
 		while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 			ibmvscsi_handle_crq(crq, hostdata);
 			crq->valid = 0x00;
 		}

 		vio_enable_interrupts(vdev);
 		if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
 			vio_disable_interrupts(vdev);
 			ibmvscsi_handle_crq(crq, hostdata);
 			crq->valid = 0x00;
 		} else {
 			done = 1;
 		}
 	}
 }

 static void gather_partition_info(void)
 {
 	struct device_node *rootdn;

 	char *ppartition_name;
 	unsigned int *p_number_ptr;

 	/* Retrieve information about this partition */
 	rootdn = find_path_device("/");
 	if (!rootdn) {
 		return;
 	}

 	ppartition_name =
 		get_property(rootdn, "ibm,partition-name", NULL);
 	if (ppartition_name)
 		strncpy(partition_name, ppartition_name,
 				sizeof(partition_name));
 	p_number_ptr =
 		(unsigned int *)get_property(rootdn, "ibm,partition-no",
 					     NULL);
 	if (p_number_ptr)
 		partition_number = *p_number_ptr;
 }

 static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
 {
 	memset(&hostdata->madapter_info, 0x00,
 			sizeof(hostdata->madapter_info));

 	printk(KERN_INFO "rpa_vscsi: SPR_VERSION: %s\n", SRP_VERSION);
 	strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);

 	strncpy(hostdata->madapter_info.partition_name, partition_name,
 			sizeof(hostdata->madapter_info.partition_name));

 	hostdata->madapter_info.partition_number = partition_number;

 	hostdata->madapter_info.mad_version = 1;
 	hostdata->madapter_info.os_type = 2;
 }

 /**
  * initialize_crq_queue: - Initializes and registers CRQ with hypervisor
  * @queue:	crq_queue to initialize and register
  * @hostdata:	ibmvscsi_host_data of host
  *
  * Allocates a page for messages, maps it for dma, and registers
  * the crq with the hypervisor.
  * Returns zero on success.
  */
 int ibmvscsi_init_crq_queue(struct crq_queue *queue,
 			    struct ibmvscsi_host_data *hostdata,
 			    int max_requests)
 {
 	int rc;
 	int retrc;
 	struct vio_dev *vdev = to_vio_dev(hostdata->dev);

 	queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);

 	if (!queue->msgs)
 		goto malloc_failed;
 	queue->size = PAGE_SIZE / sizeof(*queue->msgs);

 	queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
 					  queue->size * sizeof(*queue->msgs),
 					  DMA_BIDIRECTIONAL);

 	if (dma_mapping_error(queue->msg_token))
 		goto map_failed;

 	gather_partition_info();
 	set_adapter_info(hostdata);

 	retrc = rc = plpar_hcall_norets(H_REG_CRQ,
 				vdev->unit_address,
 				queue->msg_token, PAGE_SIZE);
 	if (rc == H_RESOURCE)
 		/* maybe kexecing and resource is busy. try a reset */
 		rc = ibmvscsi_reset_crq_queue(queue,
 					      hostdata);

 	if (rc == 2) {
 		/* Adapter is good, but other end is not ready */
 		printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
 		retrc = 0;
 	} else if (rc != 0) {
 		printk(KERN_WARNING "ibmvscsi: Error %d opening adapter\n", rc);
 		goto reg_crq_failed;
 	}

 	if (request_irq(vdev->irq,
 			ibmvscsi_handle_event,
 			0, "ibmvscsi", (void *)hostdata) != 0) {
 		printk(KERN_ERR "ibmvscsi: couldn't register irq 0x%x\n",
 		       vdev->irq);
 		goto req_irq_failed;
 	}

 	rc = vio_enable_interrupts(vdev);
 	if (rc != 0) {
 		printk(KERN_ERR "ibmvscsi:  Error %d enabling interrupts!!!\n",
 		       rc);
 		goto req_irq_failed;
 	}

 	queue->cur = 0;
 	spin_lock_init(&queue->lock);

 	tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
 		     (unsigned long)hostdata);

 	return retrc;

       req_irq_failed:
 	do {
 		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
       reg_crq_failed:
 	dma_unmap_single(hostdata->dev,
 			 queue->msg_token,
 			 queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
       map_failed:
 	free_page((unsigned long)queue->msgs);
       malloc_failed:
 	return -1;
 }

 /**
  * reenable_crq_queue: - reenables a crq after
  * @queue:	crq_queue to initialize and register
  * @hostdata:	ibmvscsi_host_data of host
  *
  */
 int ibmvscsi_reenable_crq_queue(struct crq_queue *queue,
 				 struct ibmvscsi_host_data *hostdata)
 {
 	int rc;
 	struct vio_dev *vdev = to_vio_dev(hostdata->dev);

 	/* Re-enable the CRQ */
 	do {
 		rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
 	} while ((rc == H_IN_PROGRESS) || (rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));

 	if (rc)
 		printk(KERN_ERR "ibmvscsi: Error %d enabling adapter\n", rc);
 	return rc;
 }

 /**
  * reset_crq_queue: - resets a crq after a failure
  * @queue:	crq_queue to initialize and register
  * @hostdata:	ibmvscsi_host_data of host
  *
  */
 int ibmvscsi_reset_crq_queue(struct crq_queue *queue,
 			      struct ibmvscsi_host_data *hostdata)
 {
 	int rc;
 	struct vio_dev *vdev = to_vio_dev(hostdata->dev);

 	/* Close the CRQ */
 	do {
 		rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
 	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));

 	/* Clean out the queue */
 	memset(queue->msgs, 0x00, PAGE_SIZE);
 	queue->cur = 0;

 	set_adapter_info(hostdata);

 	/* And re-open it again */
 	rc = plpar_hcall_norets(H_REG_CRQ,
 				vdev->unit_address,
 				queue->msg_token, PAGE_SIZE);
 	if (rc == 2) {
 		/* Adapter is good, but other end is not ready */
 		printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
 	} else if (rc != 0) {
 		printk(KERN_WARNING
 		       "ibmvscsi: couldn't register crq--rc 0x%x\n", rc);
 	}
 	return rc;
 }
	/* ------------------------------------------------------------
	* rpa_vscsi.c
	* (C) Copyright IBM Corporation 1994, 2003
	* Authors: Colin DeVilbiss (devilbis@us.ibm.com)
	* Santiago Leon (santil@us.ibm.com)
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
	* USA
	*
	* ------------------------------------------------------------
	* RPA-specific functions of the SCSI host adapter for Virtual I/O devices
	*
	* This driver allows the Linux SCSI peripheral drivers to directly
	* access devices in the hosting partition, either on an iSeries
	* hypervisor system or a converged hypervisor system.
	*/

	#include <asm/vio.h>
	#include <asm/prom.h>
	#include <asm/iommu.h>
	#include <asm/hvcall.h>
	#include <linux/dma-mapping.h>
	#include <linux/interrupt.h>
	#include "ibmvscsi.h"

	static char partition_name[97] = "UNKNOWN";
	static unsigned int partition_number = -1;

	/* ------------------------------------------------------------
	* Routines for managing the command/response queue
	*/
	/**
	* ibmvscsi_handle_event: - Interrupt handler for crq events
	* @irq: number of irq to handle, not used
	* @dev_instance: ibmvscsi_host_data of host that received interrupt
	* @regs: pt_regs with registers
	*
	* Disables interrupts and schedules srp_task
	* Always returns IRQ_HANDLED
	*/
	static irqreturn_t ibmvscsi_handle_event(int irq,
	void *dev_instance,
	struct pt_regs *regs)
	{
	struct ibmvscsi_host_data *hostdata =
	(struct ibmvscsi_host_data *)dev_instance;
	vio_disable_interrupts(to_vio_dev(hostdata->dev));
	tasklet_schedule(&hostdata->srp_task);
	return IRQ_HANDLED;
	}

	/**
	* release_crq_queue: - Deallocates data and unregisters CRQ
	* @queue: crq_queue to initialize and register
	* @host_data: ibmvscsi_host_data of host
	*
	* Frees irq, deallocates a page for messages, unmaps dma, and unregisters
	* the crq with the hypervisor.
	*/
	void ibmvscsi_release_crq_queue(struct crq_queue *queue,
	struct ibmvscsi_host_data *hostdata,
	int max_requests)
	{
	long rc;
	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
	free_irq(vdev->irq, (void *)hostdata);
	tasklet_kill(&hostdata->srp_task);
	do {
	rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
	} while ((rc == H_BUSY) \|\| (H_IS_LONG_BUSY(rc)));
	dma_unmap_single(hostdata->dev,
	queue->msg_token,
	queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
	free_page((unsigned long)queue->msgs);
	}

	/**
	* crq_queue_next_crq: - Returns the next entry in message queue
	* @queue: crq_queue to use
	*
	* Returns pointer to next entry in queue, or NULL if there are no new
	* entried in the CRQ.
	*/
	static struct viosrp_crq crq_queue_next_crq(struct crq_queue queue)
	{
	struct viosrp_crq *crq;
	unsigned long flags;

	spin_lock_irqsave(&queue->lock, flags);
	crq = &queue->msgs[queue->cur];
	if (crq->valid & 0x80) {
	if (++queue->cur == queue->size)
	queue->cur = 0;
	} else
	crq = NULL;
	spin_unlock_irqrestore(&queue->lock, flags);

	return crq;
	}

	/**
	* ibmvscsi_send_crq: - Send a CRQ
	* @hostdata: the adapter
	* @word1: the first 64 bits of the data
	* @word2: the second 64 bits of the data
	*/
	int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata, u64 word1, u64 word2)
	{
	struct vio_dev *vdev = to_vio_dev(hostdata->dev);

	return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
	}

	/**
	* ibmvscsi_task: - Process srps asynchronously
	* @data: ibmvscsi_host_data of host
	*/
	static void ibmvscsi_task(void *data)
	{
	struct ibmvscsi_host_data hostdata = (struct ibmvscsi_host_data )data;
	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
	struct viosrp_crq *crq;
	int done = 0;

	while (!done) {
	/* Pull all the valid messages off the CRQ */
	while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
	ibmvscsi_handle_crq(crq, hostdata);
	crq->valid = 0x00;
	}

	vio_enable_interrupts(vdev);
	if ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
	vio_disable_interrupts(vdev);
	ibmvscsi_handle_crq(crq, hostdata);
	crq->valid = 0x00;
	} else {
	done = 1;
	}
	}
	}

	static void gather_partition_info(void)
	{
	struct device_node *rootdn;

	char *ppartition_name;
	unsigned int *p_number_ptr;

	/* Retrieve information about this partition */
	rootdn = find_path_device("/");
	if (!rootdn) {
	return;
	}

	ppartition_name =
	get_property(rootdn, "ibm,partition-name", NULL);
	if (ppartition_name)
	strncpy(partition_name, ppartition_name,
	sizeof(partition_name));
	p_number_ptr =
	(unsigned int *)get_property(rootdn, "ibm,partition-no",
	NULL);
	if (p_number_ptr)
	partition_number = *p_number_ptr;
	}

	static void set_adapter_info(struct ibmvscsi_host_data *hostdata)
	{
	memset(&hostdata->madapter_info, 0x00,
	sizeof(hostdata->madapter_info));

	printk(KERN_INFO "rpa_vscsi: SPR_VERSION: %s\n", SRP_VERSION);
	strcpy(hostdata->madapter_info.srp_version, SRP_VERSION);

	strncpy(hostdata->madapter_info.partition_name, partition_name,
	sizeof(hostdata->madapter_info.partition_name));

	hostdata->madapter_info.partition_number = partition_number;

	hostdata->madapter_info.mad_version = 1;
	hostdata->madapter_info.os_type = 2;
	}

	/**
	* initialize_crq_queue: - Initializes and registers CRQ with hypervisor
	* @queue: crq_queue to initialize and register
	* @hostdata: ibmvscsi_host_data of host
	*
	* Allocates a page for messages, maps it for dma, and registers
	* the crq with the hypervisor.
	* Returns zero on success.
	*/
	int ibmvscsi_init_crq_queue(struct crq_queue *queue,
	struct ibmvscsi_host_data *hostdata,
	int max_requests)
	{
	int rc;
	int retrc;
	struct vio_dev *vdev = to_vio_dev(hostdata->dev);

	queue->msgs = (struct viosrp_crq *)get_zeroed_page(GFP_KERNEL);

	if (!queue->msgs)
	goto malloc_failed;
	queue->size = PAGE_SIZE / sizeof(*queue->msgs);

	queue->msg_token = dma_map_single(hostdata->dev, queue->msgs,
	queue->size * sizeof(*queue->msgs),
	DMA_BIDIRECTIONAL);

	if (dma_mapping_error(queue->msg_token))
	goto map_failed;

	gather_partition_info();
	set_adapter_info(hostdata);

	retrc = rc = plpar_hcall_norets(H_REG_CRQ,
	vdev->unit_address,
	queue->msg_token, PAGE_SIZE);
	if (rc == H_RESOURCE)
	/* maybe kexecing and resource is busy. try a reset */
	rc = ibmvscsi_reset_crq_queue(queue,
	hostdata);

	if (rc == 2) {
	/* Adapter is good, but other end is not ready */
	printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
	retrc = 0;
	} else if (rc != 0) {
	printk(KERN_WARNING "ibmvscsi: Error %d opening adapter\n", rc);
	goto reg_crq_failed;
	}

	if (request_irq(vdev->irq,
	ibmvscsi_handle_event,
	0, "ibmvscsi", (void *)hostdata) != 0) {
	printk(KERN_ERR "ibmvscsi: couldn't register irq 0x%x\n",
	vdev->irq);
	goto req_irq_failed;
	}

	rc = vio_enable_interrupts(vdev);
	if (rc != 0) {
	printk(KERN_ERR "ibmvscsi: Error %d enabling interrupts!!!\n",
	rc);
	goto req_irq_failed;
	}

	queue->cur = 0;
	spin_lock_init(&queue->lock);

	tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
	(unsigned long)hostdata);

	return retrc;

	req_irq_failed:
	do {
	rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
	} while ((rc == H_BUSY) \|\| (H_IS_LONG_BUSY(rc)));
	reg_crq_failed:
	dma_unmap_single(hostdata->dev,
	queue->msg_token,
	queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
	map_failed:
	free_page((unsigned long)queue->msgs);
	malloc_failed:
	return -1;
	}

	/**
	* reenable_crq_queue: - reenables a crq after
	* @queue: crq_queue to initialize and register
	* @hostdata: ibmvscsi_host_data of host
	*
	*/
	int ibmvscsi_reenable_crq_queue(struct crq_queue *queue,
	struct ibmvscsi_host_data *hostdata)
	{
	int rc;
	struct vio_dev *vdev = to_vio_dev(hostdata->dev);

	/* Re-enable the CRQ */
	do {
	rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address);
	} while ((rc == H_IN_PROGRESS) \|\| (rc == H_BUSY) \|\| (H_IS_LONG_BUSY(rc)));

	if (rc)
	printk(KERN_ERR "ibmvscsi: Error %d enabling adapter\n", rc);
	return rc;
	}

	/**
	* reset_crq_queue: - resets a crq after a failure
	* @queue: crq_queue to initialize and register
	* @hostdata: ibmvscsi_host_data of host
	*
	*/
	int ibmvscsi_reset_crq_queue(struct crq_queue *queue,
	struct ibmvscsi_host_data *hostdata)
	{
	int rc;
	struct vio_dev *vdev = to_vio_dev(hostdata->dev);

	/* Close the CRQ */
	do {
	rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
	} while ((rc == H_BUSY) \|\| (H_IS_LONG_BUSY(rc)));

	/* Clean out the queue */
	memset(queue->msgs, 0x00, PAGE_SIZE);
	queue->cur = 0;

	set_adapter_info(hostdata);

	/* And re-open it again */
	rc = plpar_hcall_norets(H_REG_CRQ,
	vdev->unit_address,
	queue->msg_token, PAGE_SIZE);
	if (rc == 2) {
	/* Adapter is good, but other end is not ready */
	printk(KERN_WARNING "ibmvscsi: Partner adapter not ready\n");
	} else if (rc != 0) {
	printk(KERN_WARNING
	"ibmvscsi: couldn't register crq--rc 0x%x\n", rc);
	}
	return rc;
	}