diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/dma/idxd/irq.c | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c new file mode 100644 index 000000000..fc9579180 --- /dev/null +++ b/drivers/dma/idxd/irq.c @@ -0,0 +1,277 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2019 Intel Corporation. All rights rsvd. */ +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/io-64-nonatomic-lo-hi.h> +#include <linux/dmaengine.h> +#include <uapi/linux/idxd.h> +#include "../dmaengine.h" +#include "idxd.h" +#include "registers.h" + +static void idxd_device_reinit(struct work_struct *work) +{ + struct idxd_device *idxd = container_of(work, struct idxd_device, work); + struct device *dev = &idxd->pdev->dev; + int rc, i; + + idxd_device_reset(idxd); + rc = idxd_device_config(idxd); + if (rc < 0) + goto out; + + rc = idxd_device_enable(idxd); + if (rc < 0) + goto out; + + for (i = 0; i < idxd->max_wqs; i++) { + struct idxd_wq *wq = &idxd->wqs[i]; + + if (wq->state == IDXD_WQ_ENABLED) { + rc = idxd_wq_enable(wq); + if (rc < 0) { + dev_warn(dev, "Unable to re-enable wq %s\n", + dev_name(&wq->conf_dev)); + } + } + } + + return; + + out: + idxd_device_wqs_clear_state(idxd); +} + +irqreturn_t idxd_irq_handler(int vec, void *data) +{ + struct idxd_irq_entry *irq_entry = data; + struct idxd_device *idxd = irq_entry->idxd; + + idxd_mask_msix_vector(idxd, irq_entry->id); + return IRQ_WAKE_THREAD; +} + +static int process_misc_interrupts(struct idxd_device *idxd, u32 cause) +{ + struct device *dev = &idxd->pdev->dev; + union gensts_reg gensts; + u32 val = 0; + int i; + bool err = false; + + if (cause & IDXD_INTC_ERR) { + spin_lock_bh(&idxd->dev_lock); + for (i = 0; i < 4; i++) + idxd->sw_err.bits[i] = ioread64(idxd->reg_base + + IDXD_SWERR_OFFSET + i * sizeof(u64)); + + iowrite64(idxd->sw_err.bits[0] & IDXD_SWERR_ACK, + idxd->reg_base + IDXD_SWERR_OFFSET); + + if (idxd->sw_err.valid && idxd->sw_err.wq_idx_valid) { + int id = idxd->sw_err.wq_idx; + struct idxd_wq *wq = &idxd->wqs[id]; + + if (wq->type == IDXD_WQT_USER) + wake_up_interruptible(&wq->err_queue); + } else { + int i; + + for (i = 0; i < idxd->max_wqs; i++) { + struct idxd_wq *wq = &idxd->wqs[i]; + + if (wq->type == IDXD_WQT_USER) + wake_up_interruptible(&wq->err_queue); + } + } + + spin_unlock_bh(&idxd->dev_lock); + val |= IDXD_INTC_ERR; + + for (i = 0; i < 4; i++) + dev_warn(dev, "err[%d]: %#16.16llx\n", + i, idxd->sw_err.bits[i]); + err = true; + } + + if (cause & IDXD_INTC_CMD) { + val |= IDXD_INTC_CMD; + complete(idxd->cmd_done); + } + + if (cause & IDXD_INTC_OCCUPY) { + /* Driver does not utilize occupancy interrupt */ + val |= IDXD_INTC_OCCUPY; + } + + if (cause & IDXD_INTC_PERFMON_OVFL) { + /* + * Driver does not utilize perfmon counter overflow interrupt + * yet. + */ + val |= IDXD_INTC_PERFMON_OVFL; + } + + val ^= cause; + if (val) + dev_warn_once(dev, "Unexpected interrupt cause bits set: %#x\n", + val); + + if (!err) + return 0; + + gensts.bits = ioread32(idxd->reg_base + IDXD_GENSTATS_OFFSET); + if (gensts.state == IDXD_DEVICE_STATE_HALT) { + idxd->state = IDXD_DEV_HALTED; + if (gensts.reset_type == IDXD_DEVICE_RESET_SOFTWARE) { + /* + * If we need a software reset, we will throw the work + * on a system workqueue in order to allow interrupts + * for the device command completions. + */ + INIT_WORK(&idxd->work, idxd_device_reinit); + queue_work(idxd->wq, &idxd->work); + } else { + spin_lock_bh(&idxd->dev_lock); + idxd_device_wqs_clear_state(idxd); + dev_err(&idxd->pdev->dev, + "idxd halted, need %s.\n", + gensts.reset_type == IDXD_DEVICE_RESET_FLR ? + "FLR" : "system reset"); + spin_unlock_bh(&idxd->dev_lock); + return -ENXIO; + } + } + + return 0; +} + +irqreturn_t idxd_misc_thread(int vec, void *data) +{ + struct idxd_irq_entry *irq_entry = data; + struct idxd_device *idxd = irq_entry->idxd; + int rc; + u32 cause; + + cause = ioread32(idxd->reg_base + IDXD_INTCAUSE_OFFSET); + if (cause) + iowrite32(cause, idxd->reg_base + IDXD_INTCAUSE_OFFSET); + + while (cause) { + rc = process_misc_interrupts(idxd, cause); + if (rc < 0) + break; + cause = ioread32(idxd->reg_base + IDXD_INTCAUSE_OFFSET); + if (cause) + iowrite32(cause, idxd->reg_base + IDXD_INTCAUSE_OFFSET); + } + + idxd_unmask_msix_vector(idxd, irq_entry->id); + return IRQ_HANDLED; +} + +static int irq_process_pending_llist(struct idxd_irq_entry *irq_entry, + int *processed) +{ + struct idxd_desc *desc, *t; + struct llist_node *head; + int queued = 0; + + *processed = 0; + head = llist_del_all(&irq_entry->pending_llist); + if (!head) + return 0; + + llist_for_each_entry_safe(desc, t, head, llnode) { + if (desc->completion->status) { + idxd_dma_complete_txd(desc, IDXD_COMPLETE_NORMAL); + idxd_free_desc(desc->wq, desc); + (*processed)++; + } else { + list_add_tail(&desc->list, &irq_entry->work_list); + queued++; + } + } + + return queued; +} + +static int irq_process_work_list(struct idxd_irq_entry *irq_entry, + int *processed) +{ + struct list_head *node, *next; + int queued = 0; + + *processed = 0; + if (list_empty(&irq_entry->work_list)) + return 0; + + 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) { + list_del(&desc->list); + /* process and callback */ + idxd_dma_complete_txd(desc, IDXD_COMPLETE_NORMAL); + idxd_free_desc(desc->wq, desc); + (*processed)++; + } else { + queued++; + } + } + + return queued; +} + +static int idxd_desc_process(struct idxd_irq_entry *irq_entry) +{ + int rc, processed, total = 0; + + /* + * There are two lists we are processing. The pending_llist is where + * submmiter adds all the submitted descriptor after sending it to + * the workqueue. It's a lockless singly linked list. The work_list + * is the common linux double linked list. We are in a scenario of + * multiple producers and a single consumer. The producers are all + * the kernel submitters of descriptors, and the consumer is the + * kernel irq handler thread for the msix vector when using threaded + * irq. To work with the restrictions of llist to remain lockless, + * we are doing the following steps: + * 1. Iterate through the work_list and process any completed + * descriptor. Delete the completed entries during iteration. + * 2. llist_del_all() from the pending list. + * 3. Iterate through the llist that was deleted from the pending list + * and process the completed entries. + * 4. If the entry is still waiting on hardware, list_add_tail() to + * the work_list. + * 5. Repeat until no more descriptors. + */ + do { + rc = irq_process_work_list(irq_entry, &processed); + total += processed; + if (rc != 0) + continue; + + rc = irq_process_pending_llist(irq_entry, &processed); + total += processed; + } while (rc != 0); + + return total; +} + +irqreturn_t idxd_wq_thread(int irq, void *data) +{ + struct idxd_irq_entry *irq_entry = data; + int processed; + + processed = idxd_desc_process(irq_entry); + idxd_unmask_msix_vector(irq_entry->idxd, irq_entry->id); + + if (processed == 0) + return IRQ_NONE; + + return IRQ_HANDLED; +} |