diff options
| -rw-r--r-- | drivers/misc/cxl/Kconfig | 5 | ||||
| -rw-r--r-- | drivers/misc/cxl/api.c | 17 | ||||
| -rw-r--r-- | drivers/misc/cxl/cxl.h | 7 | ||||
| -rw-r--r-- | drivers/misc/cxl/file.c | 64 | ||||
| -rw-r--r-- | include/misc/cxl.h | 48 | ||||
| -rw-r--r-- | include/uapi/misc/cxl.h | 17 |
6 files changed, 149 insertions, 9 deletions
diff --git a/drivers/misc/cxl/Kconfig b/drivers/misc/cxl/Kconfig index 8756d06e2bb8..560412cd4c98 100644 --- a/drivers/misc/cxl/Kconfig +++ b/drivers/misc/cxl/Kconfig @@ -15,12 +15,17 @@ config CXL_EEH bool default n +config CXL_AFU_DRIVER_OPS + bool + default n + config CXL tristate "Support for IBM Coherent Accelerators (CXL)" depends on PPC_POWERNV && PCI_MSI && EEH select CXL_BASE select CXL_KERNEL_API select CXL_EEH + select CXL_AFU_DRIVER_OPS default m help Select this option to enable driver support for IBM Coherent diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index 99081b821f12..f11dc0e5fdd6 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -333,6 +333,23 @@ struct cxl_context *cxl_fops_get_context(struct file *file) } EXPORT_SYMBOL_GPL(cxl_fops_get_context); +void cxl_set_driver_ops(struct cxl_context *ctx, + struct cxl_afu_driver_ops *ops) +{ + WARN_ON(!ops->fetch_event || !ops->event_delivered); + atomic_set(&ctx->afu_driver_events, 0); + ctx->afu_driver_ops = ops; +} +EXPORT_SYMBOL_GPL(cxl_set_driver_ops); + +void cxl_context_events_pending(struct cxl_context *ctx, + unsigned int new_events) +{ + atomic_add(new_events, &ctx->afu_driver_events); + wake_up_all(&ctx->wq); +} +EXPORT_SYMBOL_GPL(cxl_context_events_pending); + int cxl_start_work(struct cxl_context *ctx, struct cxl_ioctl_start_work *work) { diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h index ce2b9d513069..422ee53868a8 100644 --- a/drivers/misc/cxl/cxl.h +++ b/drivers/misc/cxl/cxl.h @@ -24,6 +24,7 @@ #include <asm/reg.h> #include <misc/cxl-base.h> +#include <misc/cxl.h> #include <uapi/misc/cxl.h> extern uint cxl_verbose; @@ -34,7 +35,7 @@ extern uint cxl_verbose; * Bump version each time a user API change is made, whether it is * backwards compatible ot not. */ -#define CXL_API_VERSION 2 +#define CXL_API_VERSION 3 #define CXL_API_VERSION_COMPATIBLE 1 /* @@ -528,6 +529,10 @@ struct cxl_context { bool pending_fault; bool pending_afu_err; + /* Used by AFU drivers for driver specific event delivery */ + struct cxl_afu_driver_ops *afu_driver_ops; + atomic_t afu_driver_events; + struct rcu_head rcu; }; diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c index eec468f1612f..5fb9894b157f 100644 --- a/drivers/misc/cxl/file.c +++ b/drivers/misc/cxl/file.c @@ -293,6 +293,17 @@ int afu_mmap(struct file *file, struct vm_area_struct *vm) return cxl_context_iomap(ctx, vm); } +static inline bool ctx_event_pending(struct cxl_context *ctx) +{ + if (ctx->pending_irq || ctx->pending_fault || ctx->pending_afu_err) + return true; + + if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events)) + return true; + + return false; +} + unsigned int afu_poll(struct file *file, struct poll_table_struct *poll) { struct cxl_context *ctx = file->private_data; @@ -305,8 +316,7 @@ unsigned int afu_poll(struct file *file, struct poll_table_struct *poll) pr_devel("afu_poll wait done pe: %i\n", ctx->pe); spin_lock_irqsave(&ctx->lock, flags); - if (ctx->pending_irq || ctx->pending_fault || - ctx->pending_afu_err) + if (ctx_event_pending(ctx)) mask |= POLLIN | POLLRDNORM; else if (ctx->status == CLOSED) /* Only error on closed when there are no futher events pending @@ -319,16 +329,46 @@ unsigned int afu_poll(struct file *file, struct poll_table_struct *poll) return mask; } -static inline int ctx_event_pending(struct cxl_context *ctx) +static ssize_t afu_driver_event_copy(struct cxl_context *ctx, + char __user *buf, + struct cxl_event *event, + struct cxl_event_afu_driver_reserved *pl) { - return (ctx->pending_irq || ctx->pending_fault || - ctx->pending_afu_err || (ctx->status == CLOSED)); + /* Check event */ + if (!pl) { + ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL); + return -EFAULT; + } + + /* Check event size */ + event->header.size += pl->data_size; + if (event->header.size > CXL_READ_MIN_SIZE) { + ctx->afu_driver_ops->event_delivered(ctx, pl, -EINVAL); + return -EFAULT; + } + + /* Copy event header */ + if (copy_to_user(buf, event, sizeof(struct cxl_event_header))) { + ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT); + return -EFAULT; + } + + /* Copy event data */ + buf += sizeof(struct cxl_event_header); + if (copy_to_user(buf, &pl->data, pl->data_size)) { + ctx->afu_driver_ops->event_delivered(ctx, pl, -EFAULT); + return -EFAULT; + } + + ctx->afu_driver_ops->event_delivered(ctx, pl, 0); /* Success */ + return event->header.size; } ssize_t afu_read(struct file *file, char __user *buf, size_t count, loff_t *off) { struct cxl_context *ctx = file->private_data; + struct cxl_event_afu_driver_reserved *pl = NULL; struct cxl_event event; unsigned long flags; int rc; @@ -344,7 +384,7 @@ ssize_t afu_read(struct file *file, char __user *buf, size_t count, for (;;) { prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE); - if (ctx_event_pending(ctx)) + if (ctx_event_pending(ctx) || (ctx->status == CLOSED)) break; if (!cxl_ops->link_ok(ctx->afu->adapter, ctx->afu)) { @@ -374,7 +414,12 @@ ssize_t afu_read(struct file *file, char __user *buf, size_t count, memset(&event, 0, sizeof(event)); event.header.process_element = ctx->pe; event.header.size = sizeof(struct cxl_event_header); - if (ctx->pending_irq) { + if (ctx->afu_driver_ops && atomic_read(&ctx->afu_driver_events)) { + pr_devel("afu_read delivering AFU driver specific event\n"); + pl = ctx->afu_driver_ops->fetch_event(ctx); + atomic_dec(&ctx->afu_driver_events); + event.header.type = CXL_EVENT_AFU_DRIVER; + } else if (ctx->pending_irq) { pr_devel("afu_read delivering AFU interrupt\n"); event.header.size += sizeof(struct cxl_event_afu_interrupt); event.header.type = CXL_EVENT_AFU_INTERRUPT; @@ -404,6 +449,9 @@ ssize_t afu_read(struct file *file, char __user *buf, size_t count, spin_unlock_irqrestore(&ctx->lock, flags); + if (event.header.type == CXL_EVENT_AFU_DRIVER) + return afu_driver_event_copy(ctx, buf, &event, pl); + if (copy_to_user(buf, &event, event.header.size)) return -EFAULT; return event.header.size; @@ -558,7 +606,7 @@ int __init cxl_file_init(void) * If these change we really need to update API. Either change some * flags or update API version number CXL_API_VERSION. */ - BUILD_BUG_ON(CXL_API_VERSION != 2); + BUILD_BUG_ON(CXL_API_VERSION != 3); BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64); BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8); BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8); diff --git a/include/misc/cxl.h b/include/misc/cxl.h index 56560c5781b4..17419f61e611 100644 --- a/include/misc/cxl.h +++ b/include/misc/cxl.h @@ -220,4 +220,52 @@ void cxl_perst_reloads_same_image(struct cxl_afu *afu, */ ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count); +/* + * AFU driver ops allow an AFU driver to create their own events to pass to + * userspace through the file descriptor as a simpler alternative to overriding + * the read() and poll() calls that works with the generic cxl events. These + * events are given priority over the generic cxl events, so they will be + * delivered first if multiple types of events are pending. + * + * The AFU driver must call cxl_context_events_pending() to notify the cxl + * driver that new events are ready to be delivered for a specific context. + * cxl_context_events_pending() will adjust the current count of AFU driver + * events for this context, and wake up anyone waiting on the context wait + * queue. + * + * The cxl driver will then call fetch_event() to get a structure defining + * the size and address of the driver specific event data. The cxl driver + * will build a cxl header with type and process_element fields filled in, + * and header.size set to sizeof(struct cxl_event_header) + data_size. + * The total size of the event is limited to CXL_READ_MIN_SIZE (4K). + * + * fetch_event() is called with a spin lock held, so it must not sleep. + * + * The cxl driver will then deliver the event to userspace, and finally + * call event_delivered() to return the status of the operation, identified + * by cxl context and AFU driver event data pointers. + * 0 Success + * -EFAULT copy_to_user() has failed + * -EINVAL Event data pointer is NULL, or event size is greater than + * CXL_READ_MIN_SIZE. + */ +struct cxl_afu_driver_ops { + struct cxl_event_afu_driver_reserved *(*fetch_event) ( + struct cxl_context *ctx); + void (*event_delivered) (struct cxl_context *ctx, + struct cxl_event_afu_driver_reserved *event, + int rc); +}; + +/* + * Associate the above driver ops with a specific context. + * Reset the current count of AFU driver events. + */ +void cxl_set_driver_ops(struct cxl_context *ctx, + struct cxl_afu_driver_ops *ops); + +/* Notify cxl driver that new events are ready to be delivered for context */ +void cxl_context_events_pending(struct cxl_context *ctx, + unsigned int new_events); + #endif /* _MISC_CXL_H */ diff --git a/include/uapi/misc/cxl.h b/include/uapi/misc/cxl.h index 8cd334f99ddc..cbae529b7ce0 100644 --- a/include/uapi/misc/cxl.h +++ b/include/uapi/misc/cxl.h @@ -93,6 +93,7 @@ enum cxl_event_type { CXL_EVENT_AFU_INTERRUPT = 1, CXL_EVENT_DATA_STORAGE = 2, CXL_EVENT_AFU_ERROR = 3, + CXL_EVENT_AFU_DRIVER = 4, }; struct cxl_event_header { @@ -124,12 +125,28 @@ struct cxl_event_afu_error { __u64 error; }; +struct cxl_event_afu_driver_reserved { + /* + * Defines the buffer passed to the cxl driver by the AFU driver. + * + * This is not ABI since the event header.size passed to the user for + * existing events is set in the read call to sizeof(cxl_event_header) + * + sizeof(whatever event is being dispatched) and the user is already + * required to use a 4K buffer on the read call. + * + * Of course the contents will be ABI, but that's up the AFU driver. + */ + size_t data_size; + u8 data[]; +}; + struct cxl_event { struct cxl_event_header header; union { struct cxl_event_afu_interrupt irq; struct cxl_event_data_storage fault; struct cxl_event_afu_error afu_error; + struct cxl_event_afu_driver_reserved afu_driver_event; }; }; |