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-rw-r--r--drivers/dma/idxd/irq.c497
1 files changed, 497 insertions, 0 deletions
diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c
new file mode 100644
index 000000000..aa314ebec
--- /dev/null
+++ b/drivers/dma/idxd/irq.c
@@ -0,0 +1,497 @@
+// 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 <linux/delay.h>
+#include <uapi/linux/idxd.h>
+#include "../dmaengine.h"
+#include "idxd.h"
+#include "registers.h"
+
+enum irq_work_type {
+ IRQ_WORK_NORMAL = 0,
+ IRQ_WORK_PROCESS_FAULT,
+};
+
+struct idxd_resubmit {
+ struct work_struct work;
+ struct idxd_desc *desc;
+};
+
+struct idxd_int_handle_revoke {
+ struct work_struct work;
+ struct idxd_device *idxd;
+};
+
+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++) {
+ if (test_bit(i, idxd->wq_enable_map)) {
+ struct idxd_wq *wq = idxd->wqs[i];
+
+ rc = idxd_wq_enable(wq);
+ if (rc < 0) {
+ clear_bit(i, idxd->wq_enable_map);
+ dev_warn(dev, "Unable to re-enable wq %s\n",
+ dev_name(wq_confdev(wq)));
+ }
+ }
+ }
+
+ return;
+
+ out:
+ idxd_device_clear_state(idxd);
+}
+
+/*
+ * The function sends a drain descriptor for the interrupt handle. The drain ensures
+ * all descriptors with this interrupt handle is flushed and the interrupt
+ * will allow the cleanup of the outstanding descriptors.
+ */
+static void idxd_int_handle_revoke_drain(struct idxd_irq_entry *ie)
+{
+ struct idxd_wq *wq = ie_to_wq(ie);
+ struct idxd_device *idxd = wq->idxd;
+ struct device *dev = &idxd->pdev->dev;
+ struct dsa_hw_desc desc = {};
+ void __iomem *portal;
+ int rc;
+
+ /* Issue a simple drain operation with interrupt but no completion record */
+ desc.flags = IDXD_OP_FLAG_RCI;
+ desc.opcode = DSA_OPCODE_DRAIN;
+ desc.priv = 1;
+
+ if (ie->pasid != INVALID_IOASID)
+ desc.pasid = ie->pasid;
+ desc.int_handle = ie->int_handle;
+ portal = idxd_wq_portal_addr(wq);
+
+ /*
+ * The wmb() makes sure that the descriptor is all there before we
+ * issue.
+ */
+ wmb();
+ if (wq_dedicated(wq)) {
+ iosubmit_cmds512(portal, &desc, 1);
+ } else {
+ rc = idxd_enqcmds(wq, portal, &desc);
+ /* This should not fail unless hardware failed. */
+ if (rc < 0)
+ dev_warn(dev, "Failed to submit drain desc on wq %d\n", wq->id);
+ }
+}
+
+static void idxd_abort_invalid_int_handle_descs(struct idxd_irq_entry *ie)
+{
+ LIST_HEAD(flist);
+ struct idxd_desc *d, *t;
+ struct llist_node *head;
+
+ spin_lock(&ie->list_lock);
+ head = llist_del_all(&ie->pending_llist);
+ if (head) {
+ llist_for_each_entry_safe(d, t, head, llnode)
+ list_add_tail(&d->list, &ie->work_list);
+ }
+
+ list_for_each_entry_safe(d, t, &ie->work_list, list) {
+ if (d->completion->status == DSA_COMP_INT_HANDLE_INVAL)
+ list_move_tail(&d->list, &flist);
+ }
+ spin_unlock(&ie->list_lock);
+
+ list_for_each_entry_safe(d, t, &flist, list) {
+ list_del(&d->list);
+ idxd_dma_complete_txd(d, IDXD_COMPLETE_ABORT, true);
+ }
+}
+
+static void idxd_int_handle_revoke(struct work_struct *work)
+{
+ struct idxd_int_handle_revoke *revoke =
+ container_of(work, struct idxd_int_handle_revoke, work);
+ struct idxd_device *idxd = revoke->idxd;
+ struct pci_dev *pdev = idxd->pdev;
+ struct device *dev = &pdev->dev;
+ int i, new_handle, rc;
+
+ if (!idxd->request_int_handles) {
+ kfree(revoke);
+ dev_warn(dev, "Unexpected int handle refresh interrupt.\n");
+ return;
+ }
+
+ /*
+ * The loop attempts to acquire new interrupt handle for all interrupt
+ * vectors that supports a handle. If a new interrupt handle is acquired and the
+ * wq is kernel type, the driver will kill the percpu_ref to pause all
+ * ongoing descriptor submissions. The interrupt handle is then changed.
+ * After change, the percpu_ref is revived and all the pending submissions
+ * are woken to try again. A drain is sent to for the interrupt handle
+ * at the end to make sure all invalid int handle descriptors are processed.
+ */
+ for (i = 1; i < idxd->irq_cnt; i++) {
+ struct idxd_irq_entry *ie = idxd_get_ie(idxd, i);
+ struct idxd_wq *wq = ie_to_wq(ie);
+
+ if (ie->int_handle == INVALID_INT_HANDLE)
+ continue;
+
+ rc = idxd_device_request_int_handle(idxd, i, &new_handle, IDXD_IRQ_MSIX);
+ if (rc < 0) {
+ dev_warn(dev, "get int handle %d failed: %d\n", i, rc);
+ /*
+ * Failed to acquire new interrupt handle. Kill the WQ
+ * and release all the pending submitters. The submitters will
+ * get error return code and handle appropriately.
+ */
+ ie->int_handle = INVALID_INT_HANDLE;
+ idxd_wq_quiesce(wq);
+ idxd_abort_invalid_int_handle_descs(ie);
+ continue;
+ }
+
+ /* No change in interrupt handle, nothing needs to be done */
+ if (ie->int_handle == new_handle)
+ continue;
+
+ if (wq->state != IDXD_WQ_ENABLED || wq->type != IDXD_WQT_KERNEL) {
+ /*
+ * All the MSIX interrupts are allocated at once during probe.
+ * Therefore we need to update all interrupts even if the WQ
+ * isn't supporting interrupt operations.
+ */
+ ie->int_handle = new_handle;
+ continue;
+ }
+
+ mutex_lock(&wq->wq_lock);
+ reinit_completion(&wq->wq_resurrect);
+
+ /* Kill percpu_ref to pause additional descriptor submissions */
+ percpu_ref_kill(&wq->wq_active);
+
+ /* Wait for all submitters quiesce before we change interrupt handle */
+ wait_for_completion(&wq->wq_dead);
+
+ ie->int_handle = new_handle;
+
+ /* Revive percpu ref and wake up all the waiting submitters */
+ percpu_ref_reinit(&wq->wq_active);
+ complete_all(&wq->wq_resurrect);
+ mutex_unlock(&wq->wq_lock);
+
+ /*
+ * The delay here is to wait for all possible MOVDIR64B that
+ * are issued before percpu_ref_kill() has happened to have
+ * reached the PCIe domain before the drain is issued. The driver
+ * needs to ensure that the drain descriptor issued does not pass
+ * all the other issued descriptors that contain the invalid
+ * interrupt handle in order to ensure that the drain descriptor
+ * interrupt will allow the cleanup of all the descriptors with
+ * invalid interrupt handle.
+ */
+ if (wq_dedicated(wq))
+ udelay(100);
+ idxd_int_handle_revoke_drain(ie);
+ }
+ kfree(revoke);
+}
+
+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_HALT_STATE)
+ goto halt;
+
+ if (cause & IDXD_INTC_ERR) {
+ spin_lock(&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(&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_INT_HANDLE_REVOKED) {
+ struct idxd_int_handle_revoke *revoke;
+
+ val |= IDXD_INTC_INT_HANDLE_REVOKED;
+
+ revoke = kzalloc(sizeof(*revoke), GFP_ATOMIC);
+ if (revoke) {
+ revoke->idxd = idxd;
+ INIT_WORK(&revoke->work, idxd_int_handle_revoke);
+ queue_work(idxd->wq, &revoke->work);
+
+ } else {
+ dev_err(dev, "Failed to allocate work for int handle revoke\n");
+ idxd_wqs_quiesce(idxd);
+ }
+ }
+
+ 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) {
+ val |= IDXD_INTC_PERFMON_OVFL;
+ perfmon_counter_overflow(idxd);
+ }
+
+ val ^= cause;
+ if (val)
+ dev_warn_once(dev, "Unexpected interrupt cause bits set: %#x\n",
+ val);
+
+ if (!err)
+ return 0;
+
+halt:
+ 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 {
+ idxd->state = IDXD_DEV_HALTED;
+ idxd_wqs_quiesce(idxd);
+ idxd_wqs_unmap_portal(idxd);
+ idxd_device_clear_state(idxd);
+ dev_err(&idxd->pdev->dev,
+ "idxd halted, need %s.\n",
+ gensts.reset_type == IDXD_DEVICE_RESET_FLR ?
+ "FLR" : "system reset");
+ return -ENXIO;
+ }
+ }
+
+ return 0;
+}
+
+irqreturn_t idxd_misc_thread(int vec, void *data)
+{
+ struct idxd_irq_entry *irq_entry = data;
+ struct idxd_device *idxd = ie_to_idxd(irq_entry);
+ 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);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static void idxd_int_handle_resubmit_work(struct work_struct *work)
+{
+ struct idxd_resubmit *irw = container_of(work, struct idxd_resubmit, work);
+ struct idxd_desc *desc = irw->desc;
+ struct idxd_wq *wq = desc->wq;
+ int rc;
+
+ desc->completion->status = 0;
+ rc = idxd_submit_desc(wq, desc);
+ if (rc < 0) {
+ dev_dbg(&wq->idxd->pdev->dev, "Failed to resubmit desc %d to wq %d.\n",
+ desc->id, wq->id);
+ /*
+ * If the error is not -EAGAIN, it means the submission failed due to wq
+ * has been killed instead of ENQCMDS failure. Here the driver needs to
+ * notify the submitter of the failure by reporting abort status.
+ *
+ * -EAGAIN comes from ENQCMDS failure. idxd_submit_desc() will handle the
+ * abort.
+ */
+ if (rc != -EAGAIN) {
+ desc->completion->status = IDXD_COMP_DESC_ABORT;
+ idxd_dma_complete_txd(desc, IDXD_COMPLETE_ABORT, false);
+ }
+ idxd_free_desc(wq, desc);
+ }
+ kfree(irw);
+}
+
+bool idxd_queue_int_handle_resubmit(struct idxd_desc *desc)
+{
+ struct idxd_wq *wq = desc->wq;
+ struct idxd_device *idxd = wq->idxd;
+ struct idxd_resubmit *irw;
+
+ irw = kzalloc(sizeof(*irw), GFP_KERNEL);
+ if (!irw)
+ return false;
+
+ irw->desc = desc;
+ INIT_WORK(&irw->work, idxd_int_handle_resubmit_work);
+ queue_work(idxd->wq, &irw->work);
+ return true;
+}
+
+static void irq_process_pending_llist(struct idxd_irq_entry *irq_entry)
+{
+ struct idxd_desc *desc, *t;
+ struct llist_node *head;
+
+ head = llist_del_all(&irq_entry->pending_llist);
+ if (!head)
+ return;
+
+ llist_for_each_entry_safe(desc, t, head, llnode) {
+ u8 status = desc->completion->status & DSA_COMP_STATUS_MASK;
+
+ if (status) {
+ /*
+ * Check against the original status as ABORT is software defined
+ * and 0xff, which DSA_COMP_STATUS_MASK can mask out.
+ */
+ if (unlikely(desc->completion->status == IDXD_COMP_DESC_ABORT)) {
+ idxd_dma_complete_txd(desc, IDXD_COMPLETE_ABORT, true);
+ continue;
+ }
+
+ idxd_dma_complete_txd(desc, IDXD_COMPLETE_NORMAL, true);
+ } else {
+ spin_lock(&irq_entry->list_lock);
+ list_add_tail(&desc->list,
+ &irq_entry->work_list);
+ spin_unlock(&irq_entry->list_lock);
+ }
+ }
+}
+
+static void irq_process_work_list(struct idxd_irq_entry *irq_entry)
+{
+ LIST_HEAD(flist);
+ struct idxd_desc *desc, *n;
+
+ /*
+ * This lock protects list corruption from access of list outside of the irq handler
+ * thread.
+ */
+ spin_lock(&irq_entry->list_lock);
+ if (list_empty(&irq_entry->work_list)) {
+ spin_unlock(&irq_entry->list_lock);
+ return;
+ }
+
+ list_for_each_entry_safe(desc, n, &irq_entry->work_list, list) {
+ if (desc->completion->status) {
+ list_move_tail(&desc->list, &flist);
+ }
+ }
+
+ spin_unlock(&irq_entry->list_lock);
+
+ list_for_each_entry(desc, &flist, list) {
+ /*
+ * Check against the original status as ABORT is software defined
+ * and 0xff, which DSA_COMP_STATUS_MASK can mask out.
+ */
+ if (unlikely(desc->completion->status == IDXD_COMP_DESC_ABORT)) {
+ idxd_dma_complete_txd(desc, IDXD_COMPLETE_ABORT, true);
+ continue;
+ }
+
+ idxd_dma_complete_txd(desc, IDXD_COMPLETE_NORMAL, true);
+ }
+}
+
+irqreturn_t idxd_wq_thread(int irq, void *data)
+{
+ struct idxd_irq_entry *irq_entry = data;
+
+ /*
+ * 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.
+ */
+ irq_process_work_list(irq_entry);
+ irq_process_pending_llist(irq_entry);
+
+ return IRQ_HANDLED;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-18 23:16:35 +0000