diff options
| -rw-r--r-- | arch/s390/Kconfig | 10 | ||||
| -rw-r--r-- | arch/s390/include/asm/isc.h | 1 | ||||
| -rw-r--r-- | drivers/iommu/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/s390/cio/Makefile | 3 | ||||
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_drv.c | 262 | ||||
| -rw-r--r-- | drivers/s390/cio/vfio_ccw_private.h | 25 |
6 files changed, 309 insertions, 0 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index a2dcef0aacc7..b53f0359f2b6 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -672,6 +672,16 @@ config EADM_SCH To compile this driver as a module, choose M here: the module will be called eadm_sch. +config VFIO_CCW + def_tristate n + prompt "Support for VFIO-CCW subchannels" + depends on S390_CCW_IOMMU && VFIO + help + This driver allows usage of I/O subchannels via VFIO-CCW. + + To compile this driver as a module, choose M here: the + module will be called vfio_ccw. + endmenu menu "Dump support" diff --git a/arch/s390/include/asm/isc.h b/arch/s390/include/asm/isc.h index 68d7d68300f2..8a0b721a9b8d 100644 --- a/arch/s390/include/asm/isc.h +++ b/arch/s390/include/asm/isc.h @@ -16,6 +16,7 @@ #define CONSOLE_ISC 1 /* console I/O subchannel */ #define EADM_SCH_ISC 4 /* EADM subchannels */ #define CHSC_SCH_ISC 7 /* CHSC subchannels */ +#define VFIO_CCW_ISC IO_SCH_ISC /* VFIO-CCW I/O subchannels */ /* Adapter interrupts. */ #define QDIO_AIRQ_ISC IO_SCH_ISC /* I/O subchannel in qdio mode */ #define PCI_ISC 2 /* PCI I/O subchannels */ diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 37e204f3d9be..6ee3a25ae731 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -327,6 +327,14 @@ config S390_IOMMU help Support for the IOMMU API for s390 PCI devices. +config S390_CCW_IOMMU + bool "S390 CCW IOMMU Support" + depends on S390 && CCW + select IOMMU_API + help + Enables bits of IOMMU API required by VFIO. The iommu_ops + is not implemented as it is not necessary for VFIO. + config MTK_IOMMU bool "MTK IOMMU Support" depends on ARM || ARM64 diff --git a/drivers/s390/cio/Makefile b/drivers/s390/cio/Makefile index 3ab9aedeb84a..3d7390e05b2a 100644 --- a/drivers/s390/cio/Makefile +++ b/drivers/s390/cio/Makefile @@ -17,3 +17,6 @@ obj-$(CONFIG_CCWGROUP) += ccwgroup.o qdio-objs := qdio_main.o qdio_thinint.o qdio_debug.o qdio_setup.o obj-$(CONFIG_QDIO) += qdio.o + +vfio_ccw-objs += vfio_ccw_drv.o +obj-$(CONFIG_VFIO_CCW) += vfio_ccw.o diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c new file mode 100644 index 000000000000..de4f4f1b45de --- /dev/null +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -0,0 +1,262 @@ +/* + * VFIO based Physical Subchannel device driver + * + * Copyright IBM Corp. 2017 + * + * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> + * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com> + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/slab.h> + +#include <asm/isc.h> + +#include "vfio_ccw_private.h" + +/* + * Helpers + */ +static int vfio_ccw_sch_quiesce(struct subchannel *sch) +{ + struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); + DECLARE_COMPLETION_ONSTACK(completion); + int iretry, ret = 0; + + spin_lock_irq(sch->lock); + if (!sch->schib.pmcw.ena) + goto out_unlock; + ret = cio_disable_subchannel(sch); + if (ret != -EBUSY) + goto out_unlock; + + do { + iretry = 255; + + ret = cio_cancel_halt_clear(sch, &iretry); + while (ret == -EBUSY) { + /* + * Flush all I/O and wait for + * cancel/halt/clear completion. + */ + private->completion = &completion; + spin_unlock_irq(sch->lock); + + wait_for_completion_timeout(&completion, 3*HZ); + + spin_lock_irq(sch->lock); + private->completion = NULL; + ret = cio_cancel_halt_clear(sch, &iretry); + }; + + ret = cio_disable_subchannel(sch); + } while (ret == -EBUSY); + +out_unlock: + spin_unlock_irq(sch->lock); + return ret; +} + +/* + * Sysfs interfaces + */ +static ssize_t chpids_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct subchannel *sch = to_subchannel(dev); + struct chsc_ssd_info *ssd = &sch->ssd_info; + ssize_t ret = 0; + int chp; + int mask; + + for (chp = 0; chp < 8; chp++) { + mask = 0x80 >> chp; + if (ssd->path_mask & mask) + ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id); + else + ret += sprintf(buf + ret, "00 "); + } + ret += sprintf(buf+ret, "\n"); + return ret; +} + +static ssize_t pimpampom_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct subchannel *sch = to_subchannel(dev); + struct pmcw *pmcw = &sch->schib.pmcw; + + return sprintf(buf, "%02x %02x %02x\n", + pmcw->pim, pmcw->pam, pmcw->pom); +} + +static DEVICE_ATTR(chpids, 0444, chpids_show, NULL); +static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL); + +static struct attribute *vfio_subchannel_attrs[] = { + &dev_attr_chpids.attr, + &dev_attr_pimpampom.attr, + NULL, +}; + +static struct attribute_group vfio_subchannel_attr_group = { + .attrs = vfio_subchannel_attrs, +}; + +/* + * Css driver callbacks + */ +static void vfio_ccw_sch_irq(struct subchannel *sch) +{ + struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); + + inc_irq_stat(IRQIO_CIO); + + if (!private) + return; + + if (private->completion) + complete(private->completion); +} + +static int vfio_ccw_sch_probe(struct subchannel *sch) +{ + struct pmcw *pmcw = &sch->schib.pmcw; + struct vfio_ccw_private *private; + int ret; + + if (pmcw->qf) { + dev_warn(&sch->dev, "vfio: ccw: does not support QDIO: %s\n", + dev_name(&sch->dev)); + return -ENODEV; + } + + private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA); + if (!private) + return -ENOMEM; + private->sch = sch; + dev_set_drvdata(&sch->dev, private); + + spin_lock_irq(sch->lock); + sch->isc = VFIO_CCW_ISC; + ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch); + spin_unlock_irq(sch->lock); + if (ret) + goto out_free; + + ret = sysfs_create_group(&sch->dev.kobj, &vfio_subchannel_attr_group); + if (ret) + goto out_disable; + + return 0; + +out_disable: + cio_disable_subchannel(sch); +out_free: + dev_set_drvdata(&sch->dev, NULL); + kfree(private); + return ret; +} + +static int vfio_ccw_sch_remove(struct subchannel *sch) +{ + struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev); + + vfio_ccw_sch_quiesce(sch); + + sysfs_remove_group(&sch->dev.kobj, &vfio_subchannel_attr_group); + + dev_set_drvdata(&sch->dev, NULL); + + kfree(private); + + return 0; +} + +static void vfio_ccw_sch_shutdown(struct subchannel *sch) +{ + vfio_ccw_sch_quiesce(sch); +} + +/** + * vfio_ccw_sch_event - process subchannel event + * @sch: subchannel + * @process: non-zero if function is called in process context + * + * An unspecified event occurred for this subchannel. Adjust data according + * to the current operational state of the subchannel. Return zero when the + * event has been handled sufficiently or -EAGAIN when this function should + * be called again in process context. + */ +static int vfio_ccw_sch_event(struct subchannel *sch, int process) +{ + unsigned long flags; + + spin_lock_irqsave(sch->lock, flags); + if (!device_is_registered(&sch->dev)) + goto out_unlock; + + if (work_pending(&sch->todo_work)) + goto out_unlock; + + if (cio_update_schib(sch)) { + /* Not operational. */ + css_sched_sch_todo(sch, SCH_TODO_UNREG); + + /* + * TODO: + * Probably we should send the machine check to the guest. + */ + goto out_unlock; + } + +out_unlock: + spin_unlock_irqrestore(sch->lock, flags); + + return 0; +} + +static struct css_device_id vfio_ccw_sch_ids[] = { + { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, }, + { /* end of list */ }, +}; +MODULE_DEVICE_TABLE(css, vfio_ccw_sch_ids); + +static struct css_driver vfio_ccw_sch_driver = { + .drv = { + .name = "vfio_ccw", + .owner = THIS_MODULE, + }, + .subchannel_type = vfio_ccw_sch_ids, + .irq = vfio_ccw_sch_irq, + .probe = vfio_ccw_sch_probe, + .remove = vfio_ccw_sch_remove, + .shutdown = vfio_ccw_sch_shutdown, + .sch_event = vfio_ccw_sch_event, +}; + +static int __init vfio_ccw_sch_init(void) +{ + int ret; + + isc_register(VFIO_CCW_ISC); + ret = css_driver_register(&vfio_ccw_sch_driver); + if (ret) + isc_unregister(VFIO_CCW_ISC); + + return ret; +} + +static void __exit vfio_ccw_sch_exit(void) +{ + css_driver_unregister(&vfio_ccw_sch_driver); + isc_unregister(VFIO_CCW_ISC); +} +module_init(vfio_ccw_sch_init); +module_exit(vfio_ccw_sch_exit); + +MODULE_LICENSE("GPL v2"); diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h new file mode 100644 index 000000000000..38d69a59cb12 --- /dev/null +++ b/drivers/s390/cio/vfio_ccw_private.h @@ -0,0 +1,25 @@ +/* + * Private stuff for vfio_ccw driver + * + * Copyright IBM Corp. 2017 + * + * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com> + * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com> + */ + +#ifndef _VFIO_CCW_PRIVATE_H_ +#define _VFIO_CCW_PRIVATE_H_ + +#include "css.h" + +/** + * struct vfio_ccw_private + * @sch: pointer to the subchannel + * @completion: synchronization helper of the I/O completion + */ +struct vfio_ccw_private { + struct subchannel *sch; + struct completion *completion; +} __aligned(8); + +#endif |