/* ------------------------------------------------------------
* 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;
const char *ppartition_name;
const 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 = 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;
}
