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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/scsi/ibmvscsi/rpa_vscsi.c | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/scsi/ibmvscsi/rpa_vscsi.c')
-rw-r--r-- | drivers/scsi/ibmvscsi/rpa_vscsi.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/drivers/scsi/ibmvscsi/rpa_vscsi.c b/drivers/scsi/ibmvscsi/rpa_vscsi.c new file mode 100644 index 000000000000..50cb909f314f --- /dev/null +++ b/drivers/scsi/ibmvscsi/rpa_vscsi.c @@ -0,0 +1,260 @@ +/* ------------------------------------------------------------ + * 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; + spin_lock_init(&queue->lock); + + 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); + } +} |