diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/dma/idxd/irq.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/dma/idxd/irq.c')
-rw-r--r-- | drivers/dma/idxd/irq.c | 497 |
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; +} |