518 lines
13 KiB
C
518 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* VFIO based Physical Subchannel device driver
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*
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* Copyright IBM Corp. 2017
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* Copyright Red Hat, Inc. 2019
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*
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* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
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* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
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* Cornelia Huck <cohuck@redhat.com>
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/mdev.h>
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#include <asm/isc.h>
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#include "chp.h"
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#include "ioasm.h"
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#include "css.h"
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#include "vfio_ccw_private.h"
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struct workqueue_struct *vfio_ccw_work_q;
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static struct kmem_cache *vfio_ccw_io_region;
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static struct kmem_cache *vfio_ccw_cmd_region;
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static struct kmem_cache *vfio_ccw_schib_region;
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static struct kmem_cache *vfio_ccw_crw_region;
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debug_info_t *vfio_ccw_debug_msg_id;
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debug_info_t *vfio_ccw_debug_trace_id;
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/*
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* Helpers
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*/
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int vfio_ccw_sch_quiesce(struct subchannel *sch)
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{
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struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
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DECLARE_COMPLETION_ONSTACK(completion);
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int iretry, ret = 0;
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iretry = 255;
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do {
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ret = cio_cancel_halt_clear(sch, &iretry);
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if (ret == -EIO) {
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pr_err("vfio_ccw: could not quiesce subchannel 0.%x.%04x!\n",
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sch->schid.ssid, sch->schid.sch_no);
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break;
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}
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/*
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* Flush all I/O and wait for
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* cancel/halt/clear completion.
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*/
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private->completion = &completion;
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spin_unlock_irq(sch->lock);
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if (ret == -EBUSY)
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wait_for_completion_timeout(&completion, 3*HZ);
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private->completion = NULL;
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flush_workqueue(vfio_ccw_work_q);
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spin_lock_irq(sch->lock);
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ret = cio_disable_subchannel(sch);
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} while (ret == -EBUSY);
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return ret;
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}
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static void vfio_ccw_sch_io_todo(struct work_struct *work)
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{
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struct vfio_ccw_private *private;
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struct irb *irb;
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bool is_final;
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bool cp_is_finished = false;
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private = container_of(work, struct vfio_ccw_private, io_work);
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irb = &private->irb;
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is_final = !(scsw_actl(&irb->scsw) &
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(SCSW_ACTL_DEVACT | SCSW_ACTL_SCHACT));
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if (scsw_is_solicited(&irb->scsw)) {
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cp_update_scsw(&private->cp, &irb->scsw);
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if (is_final && private->state == VFIO_CCW_STATE_CP_PENDING) {
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cp_free(&private->cp);
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cp_is_finished = true;
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}
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}
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mutex_lock(&private->io_mutex);
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memcpy(private->io_region->irb_area, irb, sizeof(*irb));
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mutex_unlock(&private->io_mutex);
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/*
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* Reset to IDLE only if processing of a channel program
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* has finished. Do not overwrite a possible processing
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* state if the interrupt was unsolicited, or if the final
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* interrupt was for HSCH or CSCH.
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*/
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if (cp_is_finished)
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private->state = VFIO_CCW_STATE_IDLE;
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if (private->io_trigger)
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eventfd_signal(private->io_trigger, 1);
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}
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static void vfio_ccw_crw_todo(struct work_struct *work)
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{
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struct vfio_ccw_private *private;
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private = container_of(work, struct vfio_ccw_private, crw_work);
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if (!list_empty(&private->crw) && private->crw_trigger)
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eventfd_signal(private->crw_trigger, 1);
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}
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/*
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* Css driver callbacks
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*/
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static void vfio_ccw_sch_irq(struct subchannel *sch)
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{
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struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
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inc_irq_stat(IRQIO_CIO);
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vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INTERRUPT);
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}
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static struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch)
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{
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struct vfio_ccw_private *private;
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private = kzalloc(sizeof(*private), GFP_KERNEL);
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if (!private)
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return ERR_PTR(-ENOMEM);
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private->sch = sch;
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mutex_init(&private->io_mutex);
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private->state = VFIO_CCW_STATE_STANDBY;
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INIT_LIST_HEAD(&private->crw);
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INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo);
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INIT_WORK(&private->crw_work, vfio_ccw_crw_todo);
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private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX, sizeof(struct ccw1),
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GFP_KERNEL);
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if (!private->cp.guest_cp)
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goto out_free_private;
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private->io_region = kmem_cache_zalloc(vfio_ccw_io_region,
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GFP_KERNEL | GFP_DMA);
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if (!private->io_region)
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goto out_free_cp;
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private->cmd_region = kmem_cache_zalloc(vfio_ccw_cmd_region,
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GFP_KERNEL | GFP_DMA);
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if (!private->cmd_region)
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goto out_free_io;
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private->schib_region = kmem_cache_zalloc(vfio_ccw_schib_region,
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GFP_KERNEL | GFP_DMA);
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if (!private->schib_region)
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goto out_free_cmd;
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private->crw_region = kmem_cache_zalloc(vfio_ccw_crw_region,
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GFP_KERNEL | GFP_DMA);
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if (!private->crw_region)
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goto out_free_schib;
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return private;
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out_free_schib:
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kmem_cache_free(vfio_ccw_schib_region, private->schib_region);
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out_free_cmd:
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kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region);
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out_free_io:
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kmem_cache_free(vfio_ccw_io_region, private->io_region);
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out_free_cp:
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kfree(private->cp.guest_cp);
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out_free_private:
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mutex_destroy(&private->io_mutex);
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kfree(private);
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return ERR_PTR(-ENOMEM);
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}
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static void vfio_ccw_free_private(struct vfio_ccw_private *private)
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{
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struct vfio_ccw_crw *crw, *temp;
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list_for_each_entry_safe(crw, temp, &private->crw, next) {
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list_del(&crw->next);
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kfree(crw);
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}
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kmem_cache_free(vfio_ccw_crw_region, private->crw_region);
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kmem_cache_free(vfio_ccw_schib_region, private->schib_region);
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kmem_cache_free(vfio_ccw_cmd_region, private->cmd_region);
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kmem_cache_free(vfio_ccw_io_region, private->io_region);
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kfree(private->cp.guest_cp);
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mutex_destroy(&private->io_mutex);
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kfree(private);
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}
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static int vfio_ccw_sch_probe(struct subchannel *sch)
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{
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struct pmcw *pmcw = &sch->schib.pmcw;
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struct vfio_ccw_private *private;
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int ret = -ENOMEM;
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if (pmcw->qf) {
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dev_warn(&sch->dev, "vfio: ccw: does not support QDIO: %s\n",
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dev_name(&sch->dev));
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return -ENODEV;
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}
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private = vfio_ccw_alloc_private(sch);
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if (IS_ERR(private))
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return PTR_ERR(private);
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dev_set_drvdata(&sch->dev, private);
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private->mdev_type.sysfs_name = "io";
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private->mdev_type.pretty_name = "I/O subchannel (Non-QDIO)";
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private->mdev_types[0] = &private->mdev_type;
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ret = mdev_register_parent(&private->parent, &sch->dev,
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&vfio_ccw_mdev_driver,
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private->mdev_types, 1);
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if (ret)
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goto out_free;
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VFIO_CCW_MSG_EVENT(4, "bound to subchannel %x.%x.%04x\n",
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sch->schid.cssid, sch->schid.ssid,
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sch->schid.sch_no);
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return 0;
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out_free:
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dev_set_drvdata(&sch->dev, NULL);
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vfio_ccw_free_private(private);
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return ret;
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}
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static void vfio_ccw_sch_remove(struct subchannel *sch)
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{
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struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
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mdev_unregister_parent(&private->parent);
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dev_set_drvdata(&sch->dev, NULL);
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vfio_ccw_free_private(private);
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VFIO_CCW_MSG_EVENT(4, "unbound from subchannel %x.%x.%04x\n",
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sch->schid.cssid, sch->schid.ssid,
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sch->schid.sch_no);
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}
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static void vfio_ccw_sch_shutdown(struct subchannel *sch)
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{
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struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
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vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_CLOSE);
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vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER);
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}
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/**
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* vfio_ccw_sch_event - process subchannel event
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* @sch: subchannel
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* @process: non-zero if function is called in process context
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*
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* An unspecified event occurred for this subchannel. Adjust data according
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* to the current operational state of the subchannel. Return zero when the
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* event has been handled sufficiently or -EAGAIN when this function should
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* be called again in process context.
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*/
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static int vfio_ccw_sch_event(struct subchannel *sch, int process)
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{
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struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
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unsigned long flags;
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int rc = -EAGAIN;
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spin_lock_irqsave(sch->lock, flags);
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if (!device_is_registered(&sch->dev))
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goto out_unlock;
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if (work_pending(&sch->todo_work))
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goto out_unlock;
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rc = 0;
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if (cio_update_schib(sch))
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vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER);
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out_unlock:
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spin_unlock_irqrestore(sch->lock, flags);
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return rc;
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}
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static void vfio_ccw_queue_crw(struct vfio_ccw_private *private,
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unsigned int rsc,
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unsigned int erc,
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unsigned int rsid)
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{
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struct vfio_ccw_crw *crw;
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/*
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* If unable to allocate a CRW, just drop the event and
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* carry on. The guest will either see a later one or
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* learn when it issues its own store subchannel.
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*/
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crw = kzalloc(sizeof(*crw), GFP_ATOMIC);
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if (!crw)
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return;
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/*
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* Build the CRW based on the inputs given to us.
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*/
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crw->crw.rsc = rsc;
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crw->crw.erc = erc;
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crw->crw.rsid = rsid;
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list_add_tail(&crw->next, &private->crw);
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queue_work(vfio_ccw_work_q, &private->crw_work);
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}
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static int vfio_ccw_chp_event(struct subchannel *sch,
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struct chp_link *link, int event)
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{
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struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
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int mask = chp_ssd_get_mask(&sch->ssd_info, link);
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int retry = 255;
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if (!private || !mask)
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return 0;
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trace_vfio_ccw_chp_event(private->sch->schid, mask, event);
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VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: mask=0x%x event=%d\n",
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sch->schid.cssid,
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sch->schid.ssid, sch->schid.sch_no,
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mask, event);
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if (cio_update_schib(sch))
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return -ENODEV;
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switch (event) {
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case CHP_VARY_OFF:
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/* Path logically turned off */
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sch->opm &= ~mask;
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sch->lpm &= ~mask;
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if (sch->schib.pmcw.lpum & mask)
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cio_cancel_halt_clear(sch, &retry);
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break;
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case CHP_OFFLINE:
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/* Path is gone */
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if (sch->schib.pmcw.lpum & mask)
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cio_cancel_halt_clear(sch, &retry);
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vfio_ccw_queue_crw(private, CRW_RSC_CPATH, CRW_ERC_PERRN,
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link->chpid.id);
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break;
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case CHP_VARY_ON:
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/* Path logically turned on */
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sch->opm |= mask;
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sch->lpm |= mask;
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break;
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case CHP_ONLINE:
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/* Path became available */
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sch->lpm |= mask & sch->opm;
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vfio_ccw_queue_crw(private, CRW_RSC_CPATH, CRW_ERC_INIT,
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link->chpid.id);
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break;
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}
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return 0;
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}
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static struct css_device_id vfio_ccw_sch_ids[] = {
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{ .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
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{ /* end of list */ },
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};
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MODULE_DEVICE_TABLE(css, vfio_ccw_sch_ids);
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static struct css_driver vfio_ccw_sch_driver = {
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.drv = {
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.name = "vfio_ccw",
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.owner = THIS_MODULE,
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},
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.subchannel_type = vfio_ccw_sch_ids,
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.irq = vfio_ccw_sch_irq,
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.probe = vfio_ccw_sch_probe,
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.remove = vfio_ccw_sch_remove,
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.shutdown = vfio_ccw_sch_shutdown,
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.sch_event = vfio_ccw_sch_event,
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.chp_event = vfio_ccw_chp_event,
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};
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static int __init vfio_ccw_debug_init(void)
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{
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vfio_ccw_debug_msg_id = debug_register("vfio_ccw_msg", 16, 1,
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11 * sizeof(long));
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if (!vfio_ccw_debug_msg_id)
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goto out_unregister;
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debug_register_view(vfio_ccw_debug_msg_id, &debug_sprintf_view);
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debug_set_level(vfio_ccw_debug_msg_id, 2);
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vfio_ccw_debug_trace_id = debug_register("vfio_ccw_trace", 16, 1, 16);
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if (!vfio_ccw_debug_trace_id)
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goto out_unregister;
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debug_register_view(vfio_ccw_debug_trace_id, &debug_hex_ascii_view);
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debug_set_level(vfio_ccw_debug_trace_id, 2);
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return 0;
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out_unregister:
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debug_unregister(vfio_ccw_debug_msg_id);
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debug_unregister(vfio_ccw_debug_trace_id);
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return -1;
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}
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static void vfio_ccw_debug_exit(void)
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{
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debug_unregister(vfio_ccw_debug_msg_id);
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debug_unregister(vfio_ccw_debug_trace_id);
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}
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static void vfio_ccw_destroy_regions(void)
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{
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kmem_cache_destroy(vfio_ccw_crw_region);
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kmem_cache_destroy(vfio_ccw_schib_region);
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kmem_cache_destroy(vfio_ccw_cmd_region);
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kmem_cache_destroy(vfio_ccw_io_region);
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}
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static int __init vfio_ccw_sch_init(void)
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{
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int ret;
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ret = vfio_ccw_debug_init();
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if (ret)
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return ret;
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vfio_ccw_work_q = create_singlethread_workqueue("vfio-ccw");
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if (!vfio_ccw_work_q) {
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ret = -ENOMEM;
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goto out_regions;
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}
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vfio_ccw_io_region = kmem_cache_create_usercopy("vfio_ccw_io_region",
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sizeof(struct ccw_io_region), 0,
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SLAB_ACCOUNT, 0,
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sizeof(struct ccw_io_region), NULL);
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if (!vfio_ccw_io_region) {
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ret = -ENOMEM;
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goto out_regions;
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}
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vfio_ccw_cmd_region = kmem_cache_create_usercopy("vfio_ccw_cmd_region",
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sizeof(struct ccw_cmd_region), 0,
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SLAB_ACCOUNT, 0,
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sizeof(struct ccw_cmd_region), NULL);
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if (!vfio_ccw_cmd_region) {
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ret = -ENOMEM;
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goto out_regions;
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}
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vfio_ccw_schib_region = kmem_cache_create_usercopy("vfio_ccw_schib_region",
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sizeof(struct ccw_schib_region), 0,
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SLAB_ACCOUNT, 0,
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sizeof(struct ccw_schib_region), NULL);
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if (!vfio_ccw_schib_region) {
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ret = -ENOMEM;
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goto out_regions;
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}
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vfio_ccw_crw_region = kmem_cache_create_usercopy("vfio_ccw_crw_region",
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sizeof(struct ccw_crw_region), 0,
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SLAB_ACCOUNT, 0,
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sizeof(struct ccw_crw_region), NULL);
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if (!vfio_ccw_crw_region) {
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ret = -ENOMEM;
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goto out_regions;
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}
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ret = mdev_register_driver(&vfio_ccw_mdev_driver);
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if (ret)
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goto out_regions;
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isc_register(VFIO_CCW_ISC);
|
|
ret = css_driver_register(&vfio_ccw_sch_driver);
|
|
if (ret) {
|
|
isc_unregister(VFIO_CCW_ISC);
|
|
goto out_driver;
|
|
}
|
|
|
|
return ret;
|
|
|
|
out_driver:
|
|
mdev_unregister_driver(&vfio_ccw_mdev_driver);
|
|
out_regions:
|
|
vfio_ccw_destroy_regions();
|
|
destroy_workqueue(vfio_ccw_work_q);
|
|
vfio_ccw_debug_exit();
|
|
return ret;
|
|
}
|
|
|
|
static void __exit vfio_ccw_sch_exit(void)
|
|
{
|
|
css_driver_unregister(&vfio_ccw_sch_driver);
|
|
mdev_unregister_driver(&vfio_ccw_mdev_driver);
|
|
isc_unregister(VFIO_CCW_ISC);
|
|
vfio_ccw_destroy_regions();
|
|
destroy_workqueue(vfio_ccw_work_q);
|
|
vfio_ccw_debug_exit();
|
|
}
|
|
module_init(vfio_ccw_sch_init);
|
|
module_exit(vfio_ccw_sch_exit);
|
|
|
|
MODULE_LICENSE("GPL v2");
|