Add code to "complete" a descriptor when the descriptor or its completion address hit a fault error when SVA mode is being used. This error can be triggered due to bad programming by the user. A lock is introduced in order to protect the descriptor completion lists since the fault handler will run from the system work queue after being scheduled in the interrupt handler. Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx> Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx> Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx> --- drivers/dma/idxd/idxd.h | 5 ++ drivers/dma/idxd/init.c | 1 drivers/dma/idxd/irq.c | 143 +++++++++++++++++++++++++++++++++++++++++++---- 3 files changed, 137 insertions(+), 12 deletions(-) diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h index 43a216c42d25..b64b6266ca97 100644 --- a/drivers/dma/idxd/idxd.h +++ b/drivers/dma/idxd/idxd.h @@ -34,6 +34,11 @@ struct idxd_irq_entry { int id; struct llist_head pending_llist; struct list_head work_list; + /* + * Lock to protect access between irq thread process descriptor + * and irq thread processing error descriptor. + */ + spinlock_t list_lock; }; struct idxd_group { diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c index 626401a71fdd..1bb7637b02eb 100644 --- a/drivers/dma/idxd/init.c +++ b/drivers/dma/idxd/init.c @@ -97,6 +97,7 @@ static int idxd_setup_interrupts(struct idxd_device *idxd) for (i = 0; i < msixcnt; i++) { idxd->irq_entries[i].id = i; idxd->irq_entries[i].idxd = idxd; + spin_lock_init(&idxd->irq_entries[i].list_lock); } msix = &idxd->msix_entries[0]; diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c index 17a65a13fb64..9e6cc55ad22f 100644 --- a/drivers/dma/idxd/irq.c +++ b/drivers/dma/idxd/irq.c @@ -11,6 +11,24 @@ #include "idxd.h" #include "registers.h" +enum irq_work_type { + IRQ_WORK_NORMAL = 0, + IRQ_WORK_PROCESS_FAULT, +}; + +struct idxd_fault { + struct work_struct work; + u64 addr; + struct idxd_device *idxd; +}; + +static int irq_process_work_list(struct idxd_irq_entry *irq_entry, + enum irq_work_type wtype, + int *processed, u64 data); +static int irq_process_pending_llist(struct idxd_irq_entry *irq_entry, + enum irq_work_type wtype, + int *processed, u64 data); + static void idxd_device_reinit(struct work_struct *work) { struct idxd_device *idxd = container_of(work, struct idxd_device, work); @@ -44,6 +62,46 @@ static void idxd_device_reinit(struct work_struct *work) idxd_device_wqs_clear_state(idxd); } +static void idxd_device_fault_work(struct work_struct *work) +{ + struct idxd_fault *fault = container_of(work, struct idxd_fault, work); + struct idxd_irq_entry *ie; + int i; + int processed; + int irqcnt = fault->idxd->num_wq_irqs + 1; + + for (i = 1; i < irqcnt; i++) { + ie = &fault->idxd->irq_entries[i]; + irq_process_work_list(ie, IRQ_WORK_PROCESS_FAULT, + &processed, fault->addr); + if (processed) + break; + + irq_process_pending_llist(ie, IRQ_WORK_PROCESS_FAULT, + &processed, fault->addr); + if (processed) + break; + } + + kfree(fault); +} + +static int idxd_device_schedule_fault_process(struct idxd_device *idxd, + u64 fault_addr) +{ + struct idxd_fault *fault; + + fault = kmalloc(sizeof(*fault), GFP_ATOMIC); + if (!fault) + return -ENOMEM; + + fault->addr = fault_addr; + fault->idxd = idxd; + INIT_WORK(&fault->work, idxd_device_fault_work); + queue_work(idxd->wq, &fault->work); + return 0; +} + irqreturn_t idxd_irq_handler(int vec, void *data) { struct idxd_irq_entry *irq_entry = data; @@ -125,6 +183,16 @@ irqreturn_t idxd_misc_thread(int vec, void *data) if (!err) goto out; + /* + * This case should rarely happen and typically is due to software + * programming error by the driver. + */ + if (idxd->sw_err.valid && + idxd->sw_err.desc_valid && + idxd->sw_err.fault_addr) + idxd_device_schedule_fault_process(idxd, + idxd->sw_err.fault_addr); + gensts.bits = ioread32(idxd->reg_base + IDXD_GENSTATS_OFFSET); if (gensts.state == IDXD_DEVICE_STATE_HALT) { idxd->state = IDXD_DEV_HALTED; @@ -152,57 +220,106 @@ irqreturn_t idxd_misc_thread(int vec, void *data) return IRQ_HANDLED; } +static bool process_fault(struct idxd_desc *desc, u64 fault_addr) +{ + if ((u64)desc->hw == fault_addr || + (u64)desc->completion == fault_addr) { + idxd_dma_complete_txd(desc, IDXD_COMPLETE_DEV_FAIL); + return true; + } + + return false; +} + +static bool complete_desc(struct idxd_desc *desc) +{ + if (desc->completion->status) { + idxd_dma_complete_txd(desc, IDXD_COMPLETE_NORMAL); + return true; + } + + return false; +} + static int irq_process_pending_llist(struct idxd_irq_entry *irq_entry, - int *processed) + enum irq_work_type wtype, + int *processed, u64 data) { struct idxd_desc *desc, *t; struct llist_node *head; int queued = 0; + bool completed = false; + unsigned long flags; *processed = 0; head = llist_del_all(&irq_entry->pending_llist); if (!head) - return 0; + goto out; llist_for_each_entry_safe(desc, t, head, llnode) { - if (desc->completion->status) { - idxd_dma_complete_txd(desc, IDXD_COMPLETE_NORMAL); + if (wtype == IRQ_WORK_NORMAL) + completed = complete_desc(desc); + else if (wtype == IRQ_WORK_PROCESS_FAULT) + completed = process_fault(desc, data); + + if (completed) { idxd_free_desc(desc->wq, desc); (*processed)++; + if (wtype == IRQ_WORK_PROCESS_FAULT) + break; } else { - list_add_tail(&desc->list, &irq_entry->work_list); + spin_lock_irqsave(&irq_entry->list_lock, flags); + list_add_tail(&desc->list, + &irq_entry->work_list); + spin_unlock_irqrestore(&irq_entry->list_lock, flags); queued++; } } + out: return queued; } static int irq_process_work_list(struct idxd_irq_entry *irq_entry, - int *processed) + enum irq_work_type wtype, + int *processed, u64 data) { struct list_head *node, *next; int queued = 0; + bool completed = false; + unsigned long flags; *processed = 0; + spin_lock_irqsave(&irq_entry->list_lock, flags); if (list_empty(&irq_entry->work_list)) - return 0; + goto out; list_for_each_safe(node, next, &irq_entry->work_list) { struct idxd_desc *desc = container_of(node, struct idxd_desc, list); - if (desc->completion->status) { + spin_unlock_irqrestore(&irq_entry->list_lock, flags); + if (wtype == IRQ_WORK_NORMAL) + completed = complete_desc(desc); + else if (wtype == IRQ_WORK_PROCESS_FAULT) + completed = process_fault(desc, data); + + if (completed) { + spin_lock_irqsave(&irq_entry->list_lock, flags); list_del(&desc->list); - /* process and callback */ - idxd_dma_complete_txd(desc, IDXD_COMPLETE_NORMAL); + spin_unlock_irqrestore(&irq_entry->list_lock, flags); idxd_free_desc(desc->wq, desc); (*processed)++; + if (wtype == IRQ_WORK_PROCESS_FAULT) + return queued; } else { queued++; } + spin_lock_irqsave(&irq_entry->list_lock, flags); } + out: + spin_unlock_irqrestore(&irq_entry->list_lock, flags); return queued; } @@ -230,12 +347,14 @@ static int idxd_desc_process(struct idxd_irq_entry *irq_entry) * 5. Repeat until no more descriptors. */ do { - rc = irq_process_work_list(irq_entry, &processed); + rc = irq_process_work_list(irq_entry, IRQ_WORK_NORMAL, + &processed, 0); total += processed; if (rc != 0) continue; - rc = irq_process_pending_llist(irq_entry, &processed); + rc = irq_process_pending_llist(irq_entry, IRQ_WORK_NORMAL, + &processed, 0); total += processed; } while (rc != 0);