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path: root/drivers/dma/idxd/irq.c
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-rw-r--r--drivers/dma/idxd/irq.c261
1 files changed, 261 insertions, 0 deletions
diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c
new file mode 100644
index 000000000000..d6fcd2e60103
--- /dev/null
+++ b/drivers/dma/idxd/irq.c
@@ -0,0 +1,261 @@
+// 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"
+
+void idxd_device_wqs_clear_state(struct idxd_device *idxd)
+{
+ int i;
+
+ lockdep_assert_held(&idxd->dev_lock);
+ for (i = 0; i < idxd->max_wqs; i++) {
+ struct idxd_wq *wq = &idxd->wqs[i];
+
+ wq->state = IDXD_WQ_DISABLED;
+ }
+}
+
+static int idxd_restart(struct idxd_device *idxd)
+{
+ int i, rc;
+
+ lockdep_assert_held(&idxd->dev_lock);
+
+ rc = __idxd_device_reset(idxd);
+ if (rc < 0)
+ goto out;
+
+ 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(&idxd->pdev->dev,
+ "Unable to re-enable wq %s\n",
+ dev_name(&wq->conf_dev));
+ }
+ }
+ }
+
+ return 0;
+
+ out:
+ idxd_device_wqs_clear_state(idxd);
+ idxd->state = IDXD_DEV_HALTED;
+ return rc;
+}
+
+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;
+}
+
+irqreturn_t idxd_misc_thread(int vec, void *data)
+{
+ struct idxd_irq_entry *irq_entry = data;
+ struct idxd_device *idxd = irq_entry->idxd;
+ struct device *dev = &idxd->pdev->dev;
+ union gensts_reg gensts;
+ u32 cause, val = 0;
+ int i, rc;
+ bool err = false;
+
+ cause = ioread32(idxd->reg_base + IDXD_INTCAUSE_OFFSET);
+
+ 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_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->idxd_cdev.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->idxd_cdev.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) {
+ /* Driver does use command interrupts */
+ val |= IDXD_INTC_CMD;
+ }
+
+ 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);
+
+ iowrite32(cause, idxd->reg_base + IDXD_INTCAUSE_OFFSET);
+ if (!err)
+ return IRQ_HANDLED;
+
+ gensts.bits = ioread32(idxd->reg_base + IDXD_GENSTATS_OFFSET);
+ if (gensts.state == IDXD_DEVICE_STATE_HALT) {
+ spin_lock_bh(&idxd->dev_lock);
+ if (gensts.reset_type == IDXD_DEVICE_RESET_SOFTWARE) {
+ rc = idxd_restart(idxd);
+ if (rc < 0)
+ dev_err(&idxd->pdev->dev,
+ "idxd restart failed, device halt.");
+ } else {
+ idxd_device_wqs_clear_state(idxd);
+ idxd->state = IDXD_DEV_HALTED;
+ 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);
+ }
+
+ 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;
+
+ 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;
+
+ 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;
+}
+
+irqreturn_t idxd_wq_thread(int irq, void *data)
+{
+ struct idxd_irq_entry *irq_entry = data;
+ int rc, processed = 0, retry = 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);
+ if (rc != 0) {
+ retry++;
+ continue;
+ }
+
+ rc = irq_process_pending_llist(irq_entry, &processed);
+ } while (rc != 0 && retry != 10);
+
+ idxd_unmask_msix_vector(irq_entry->idxd, irq_entry->id);
+
+ if (processed == 0)
+ return IRQ_NONE;
+
+ return IRQ_HANDLED;
+}