--- /dev/null
+/* ------------------------------------------------------------
+ * 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/iommu.h>
+#include <asm/hvcall.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include "ibmvscsi.h"
+
+/* ------------------------------------------------------------
+ * 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_isLongBusy(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;
+ }
+ }
+}
+
+/**
+ * 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;
+ 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;
+
+ 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: 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;
+ queue->lock = SPIN_LOCK_UNLOCKED;
+
+ tasklet_init(&hostdata->srp_task, (void *)ibmvscsi_task,
+ (unsigned long)hostdata);
+
+ return 0;
+
+ req_irq_failed:
+ do {
+ rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address);
+ } while ((rc == H_Busy) || (H_isLongBusy(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;
+}
+
+/**
+ * reset_crq_queue: - resets a crq after a failure
+ * @queue: crq_queue to initialize and register
+ * @hostdata: ibmvscsi_host_data of host
+ *
+ */
+void 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_isLongBusy(rc)));
+
+ /* Clean out the queue */
+ memset(queue->msgs, 0x00, PAGE_SIZE);
+ queue->cur = 0;
+
+ /* 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);
+ }
+}
git://git.onelab.eu / linux-2.6.git / blobdiff