diff options
Diffstat (limited to 'drivers/misc/mic/host/mic_intr.c')
| -rw-r--r-- | drivers/misc/mic/host/mic_intr.c | 645 |
1 files changed, 645 insertions, 0 deletions
diff --git a/drivers/misc/mic/host/mic_intr.c b/drivers/misc/mic/host/mic_intr.c new file mode 100644 index 000000000..08ca3e372 --- /dev/null +++ b/drivers/misc/mic/host/mic_intr.c @@ -0,0 +1,645 @@ +/* + * Intel MIC Platform Software Stack (MPSS) + * + * Copyright(c) 2013 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * The full GNU General Public License is included in this distribution in + * the file called "COPYING". + * + * Intel MIC Host driver. + * + */ +#include <linux/pci.h> +#include <linux/interrupt.h> + +#include "../common/mic_dev.h" +#include "mic_device.h" + +static irqreturn_t mic_thread_fn(int irq, void *dev) +{ + struct mic_device *mdev = dev; + struct mic_intr_info *intr_info = mdev->intr_info; + struct mic_irq_info *irq_info = &mdev->irq_info; + struct mic_intr_cb *intr_cb; + struct pci_dev *pdev = mdev->pdev; + int i; + + spin_lock(&irq_info->mic_thread_lock); + for (i = intr_info->intr_start_idx[MIC_INTR_DB]; + i < intr_info->intr_len[MIC_INTR_DB]; i++) + if (test_and_clear_bit(i, &irq_info->mask)) { + list_for_each_entry(intr_cb, &irq_info->cb_list[i], + list) + if (intr_cb->thread_fn) + intr_cb->thread_fn(pdev->irq, + intr_cb->data); + } + spin_unlock(&irq_info->mic_thread_lock); + return IRQ_HANDLED; +} +/** + * mic_interrupt - Generic interrupt handler for + * MSI and INTx based interrupts. + */ +static irqreturn_t mic_interrupt(int irq, void *dev) +{ + struct mic_device *mdev = dev; + struct mic_intr_info *intr_info = mdev->intr_info; + struct mic_irq_info *irq_info = &mdev->irq_info; + struct mic_intr_cb *intr_cb; + struct pci_dev *pdev = mdev->pdev; + u32 mask; + int i; + + mask = mdev->ops->ack_interrupt(mdev); + if (!mask) + return IRQ_NONE; + + spin_lock(&irq_info->mic_intr_lock); + for (i = intr_info->intr_start_idx[MIC_INTR_DB]; + i < intr_info->intr_len[MIC_INTR_DB]; i++) + if (mask & BIT(i)) { + list_for_each_entry(intr_cb, &irq_info->cb_list[i], + list) + if (intr_cb->handler) + intr_cb->handler(pdev->irq, + intr_cb->data); + set_bit(i, &irq_info->mask); + } + spin_unlock(&irq_info->mic_intr_lock); + return IRQ_WAKE_THREAD; +} + +/* Return the interrupt offset from the index. Index is 0 based. */ +static u16 mic_map_src_to_offset(struct mic_device *mdev, + int intr_src, enum mic_intr_type type) +{ + if (type >= MIC_NUM_INTR_TYPES) + return MIC_NUM_OFFSETS; + if (intr_src >= mdev->intr_info->intr_len[type]) + return MIC_NUM_OFFSETS; + + return mdev->intr_info->intr_start_idx[type] + intr_src; +} + +/* Return next available msix_entry. */ +static struct msix_entry *mic_get_available_vector(struct mic_device *mdev) +{ + int i; + struct mic_irq_info *info = &mdev->irq_info; + + for (i = 0; i < info->num_vectors; i++) + if (!info->mic_msi_map[i]) + return &info->msix_entries[i]; + return NULL; +} + +/** + * mic_register_intr_callback - Register a callback handler for the + * given source id. + * + * @mdev: pointer to the mic_device instance + * @idx: The source id to be registered. + * @handler: The function to be called when the source id receives + * the interrupt. + * @thread_fn: thread fn. corresponding to the handler + * @data: Private data of the requester. + * Return the callback structure that was registered or an + * appropriate error on failure. + */ +static struct mic_intr_cb *mic_register_intr_callback(struct mic_device *mdev, + u8 idx, irq_handler_t handler, irq_handler_t thread_fn, + void *data) +{ + struct mic_intr_cb *intr_cb; + unsigned long flags; + int rc; + intr_cb = kmalloc(sizeof(*intr_cb), GFP_KERNEL); + + if (!intr_cb) + return ERR_PTR(-ENOMEM); + + intr_cb->handler = handler; + intr_cb->thread_fn = thread_fn; + intr_cb->data = data; + intr_cb->cb_id = ida_simple_get(&mdev->irq_info.cb_ida, + 0, 0, GFP_KERNEL); + if (intr_cb->cb_id < 0) { + rc = intr_cb->cb_id; + goto ida_fail; + } + + spin_lock(&mdev->irq_info.mic_thread_lock); + spin_lock_irqsave(&mdev->irq_info.mic_intr_lock, flags); + list_add_tail(&intr_cb->list, &mdev->irq_info.cb_list[idx]); + spin_unlock_irqrestore(&mdev->irq_info.mic_intr_lock, flags); + spin_unlock(&mdev->irq_info.mic_thread_lock); + + return intr_cb; +ida_fail: + kfree(intr_cb); + return ERR_PTR(rc); +} + +/** + * mic_unregister_intr_callback - Unregister the callback handler + * identified by its callback id. + * + * @mdev: pointer to the mic_device instance + * @idx: The callback structure id to be unregistered. + * Return the source id that was unregistered or MIC_NUM_OFFSETS if no + * such callback handler was found. + */ +static u8 mic_unregister_intr_callback(struct mic_device *mdev, u32 idx) +{ + struct list_head *pos, *tmp; + struct mic_intr_cb *intr_cb; + unsigned long flags; + int i; + + spin_lock(&mdev->irq_info.mic_thread_lock); + spin_lock_irqsave(&mdev->irq_info.mic_intr_lock, flags); + for (i = 0; i < MIC_NUM_OFFSETS; i++) { + list_for_each_safe(pos, tmp, &mdev->irq_info.cb_list[i]) { + intr_cb = list_entry(pos, struct mic_intr_cb, list); + if (intr_cb->cb_id == idx) { + list_del(pos); + ida_simple_remove(&mdev->irq_info.cb_ida, + intr_cb->cb_id); + kfree(intr_cb); + spin_unlock_irqrestore( + &mdev->irq_info.mic_intr_lock, flags); + spin_unlock(&mdev->irq_info.mic_thread_lock); + return i; + } + } + } + spin_unlock_irqrestore(&mdev->irq_info.mic_intr_lock, flags); + spin_unlock(&mdev->irq_info.mic_thread_lock); + return MIC_NUM_OFFSETS; +} + +/** + * mic_setup_msix - Initializes MSIx interrupts. + * + * @mdev: pointer to mic_device instance + * + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +static int mic_setup_msix(struct mic_device *mdev, struct pci_dev *pdev) +{ + int rc, i; + int entry_size = sizeof(*mdev->irq_info.msix_entries); + + mdev->irq_info.msix_entries = kmalloc_array(MIC_MIN_MSIX, + entry_size, GFP_KERNEL); + if (!mdev->irq_info.msix_entries) { + rc = -ENOMEM; + goto err_nomem1; + } + + for (i = 0; i < MIC_MIN_MSIX; i++) + mdev->irq_info.msix_entries[i].entry = i; + + rc = pci_enable_msix_exact(pdev, mdev->irq_info.msix_entries, + MIC_MIN_MSIX); + if (rc) { + dev_dbg(&pdev->dev, "Error enabling MSIx. rc = %d\n", rc); + goto err_enable_msix; + } + + mdev->irq_info.num_vectors = MIC_MIN_MSIX; + mdev->irq_info.mic_msi_map = kzalloc((sizeof(u32) * + mdev->irq_info.num_vectors), GFP_KERNEL); + + if (!mdev->irq_info.mic_msi_map) { + rc = -ENOMEM; + goto err_nomem2; + } + + dev_dbg(&mdev->pdev->dev, + "%d MSIx irqs setup\n", mdev->irq_info.num_vectors); + return 0; +err_nomem2: + pci_disable_msix(pdev); +err_enable_msix: + kfree(mdev->irq_info.msix_entries); +err_nomem1: + mdev->irq_info.num_vectors = 0; + return rc; +} + +/** + * mic_setup_callbacks - Initialize data structures needed + * to handle callbacks. + * + * @mdev: pointer to mic_device instance + */ +static int mic_setup_callbacks(struct mic_device *mdev) +{ + int i; + + mdev->irq_info.cb_list = kmalloc_array(MIC_NUM_OFFSETS, + sizeof(*mdev->irq_info.cb_list), + GFP_KERNEL); + if (!mdev->irq_info.cb_list) + return -ENOMEM; + + for (i = 0; i < MIC_NUM_OFFSETS; i++) + INIT_LIST_HEAD(&mdev->irq_info.cb_list[i]); + ida_init(&mdev->irq_info.cb_ida); + spin_lock_init(&mdev->irq_info.mic_intr_lock); + spin_lock_init(&mdev->irq_info.mic_thread_lock); + return 0; +} + +/** + * mic_release_callbacks - Uninitialize data structures needed + * to handle callbacks. + * + * @mdev: pointer to mic_device instance + */ +static void mic_release_callbacks(struct mic_device *mdev) +{ + unsigned long flags; + struct list_head *pos, *tmp; + struct mic_intr_cb *intr_cb; + int i; + + spin_lock(&mdev->irq_info.mic_thread_lock); + spin_lock_irqsave(&mdev->irq_info.mic_intr_lock, flags); + for (i = 0; i < MIC_NUM_OFFSETS; i++) { + if (list_empty(&mdev->irq_info.cb_list[i])) + break; + + list_for_each_safe(pos, tmp, &mdev->irq_info.cb_list[i]) { + intr_cb = list_entry(pos, struct mic_intr_cb, list); + list_del(pos); + ida_simple_remove(&mdev->irq_info.cb_ida, + intr_cb->cb_id); + kfree(intr_cb); + } + } + spin_unlock_irqrestore(&mdev->irq_info.mic_intr_lock, flags); + spin_unlock(&mdev->irq_info.mic_thread_lock); + ida_destroy(&mdev->irq_info.cb_ida); + kfree(mdev->irq_info.cb_list); +} + +/** + * mic_setup_msi - Initializes MSI interrupts. + * + * @mdev: pointer to mic_device instance + * @pdev: PCI device structure + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +static int mic_setup_msi(struct mic_device *mdev, struct pci_dev *pdev) +{ + int rc; + + rc = pci_enable_msi(pdev); + if (rc) { + dev_dbg(&pdev->dev, "Error enabling MSI. rc = %d\n", rc); + return rc; + } + + mdev->irq_info.num_vectors = 1; + mdev->irq_info.mic_msi_map = kzalloc((sizeof(u32) * + mdev->irq_info.num_vectors), GFP_KERNEL); + + if (!mdev->irq_info.mic_msi_map) { + rc = -ENOMEM; + goto err_nomem1; + } + + rc = mic_setup_callbacks(mdev); + if (rc) { + dev_err(&pdev->dev, "Error setting up callbacks\n"); + goto err_nomem2; + } + + rc = request_threaded_irq(pdev->irq, mic_interrupt, mic_thread_fn, + 0, "mic-msi", mdev); + if (rc) { + dev_err(&pdev->dev, "Error allocating MSI interrupt\n"); + goto err_irq_req_fail; + } + + dev_dbg(&pdev->dev, "%d MSI irqs setup\n", mdev->irq_info.num_vectors); + return 0; +err_irq_req_fail: + mic_release_callbacks(mdev); +err_nomem2: + kfree(mdev->irq_info.mic_msi_map); +err_nomem1: + pci_disable_msi(pdev); + mdev->irq_info.num_vectors = 0; + return rc; +} + +/** + * mic_setup_intx - Initializes legacy interrupts. + * + * @mdev: pointer to mic_device instance + * @pdev: PCI device structure + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +static int mic_setup_intx(struct mic_device *mdev, struct pci_dev *pdev) +{ + int rc; + + /* Enable intx */ + pci_intx(pdev, 1); + rc = mic_setup_callbacks(mdev); + if (rc) { + dev_err(&pdev->dev, "Error setting up callbacks\n"); + goto err_nomem; + } + + rc = request_threaded_irq(pdev->irq, mic_interrupt, mic_thread_fn, + IRQF_SHARED, "mic-intx", mdev); + if (rc) + goto err; + + dev_dbg(&pdev->dev, "intx irq setup\n"); + return 0; +err: + mic_release_callbacks(mdev); +err_nomem: + return rc; +} + +/** + * mic_next_db - Retrieve the next doorbell interrupt source id. + * The id is picked sequentially from the available pool of + * doorlbell ids. + * + * @mdev: pointer to the mic_device instance. + * + * Returns the next doorbell interrupt source. + */ +int mic_next_db(struct mic_device *mdev) +{ + int next_db; + + next_db = mdev->irq_info.next_avail_src % + mdev->intr_info->intr_len[MIC_INTR_DB]; + mdev->irq_info.next_avail_src++; + return next_db; +} + +#define COOKIE_ID_SHIFT 16 +#define GET_ENTRY(cookie) ((cookie) & 0xFFFF) +#define GET_OFFSET(cookie) ((cookie) >> COOKIE_ID_SHIFT) +#define MK_COOKIE(x, y) ((x) | (y) << COOKIE_ID_SHIFT) + +/** + * mic_request_threaded_irq - request an irq. mic_mutex needs + * to be held before calling this function. + * + * @mdev: pointer to mic_device instance + * @handler: The callback function that handles the interrupt. + * The function needs to call ack_interrupts + * (mdev->ops->ack_interrupt(mdev)) when handling the interrupts. + * @thread_fn: thread fn required by request_threaded_irq. + * @name: The ASCII name of the callee requesting the irq. + * @data: private data that is returned back when calling the + * function handler. + * @intr_src: The source id of the requester. Its the doorbell id + * for Doorbell interrupts and DMA channel id for DMA interrupts. + * @type: The type of interrupt. Values defined in mic_intr_type + * + * returns: The cookie that is transparent to the caller. Passed + * back when calling mic_free_irq. An appropriate error code + * is returned on failure. Caller needs to use IS_ERR(return_val) + * to check for failure and PTR_ERR(return_val) to obtained the + * error code. + * + */ +struct mic_irq * +mic_request_threaded_irq(struct mic_device *mdev, + irq_handler_t handler, irq_handler_t thread_fn, + const char *name, void *data, int intr_src, + enum mic_intr_type type) +{ + u16 offset; + int rc = 0; + struct msix_entry *msix = NULL; + unsigned long cookie = 0; + u16 entry; + struct mic_intr_cb *intr_cb; + struct pci_dev *pdev = mdev->pdev; + + offset = mic_map_src_to_offset(mdev, intr_src, type); + if (offset >= MIC_NUM_OFFSETS) { + dev_err(&mdev->pdev->dev, + "Error mapping index %d to a valid source id.\n", + intr_src); + rc = -EINVAL; + goto err; + } + + if (mdev->irq_info.num_vectors > 1) { + msix = mic_get_available_vector(mdev); + if (!msix) { + dev_err(&mdev->pdev->dev, + "No MSIx vectors available for use.\n"); + rc = -ENOSPC; + goto err; + } + + rc = request_threaded_irq(msix->vector, handler, thread_fn, + 0, name, data); + if (rc) { + dev_dbg(&mdev->pdev->dev, + "request irq failed rc = %d\n", rc); + goto err; + } + entry = msix->entry; + mdev->irq_info.mic_msi_map[entry] |= BIT(offset); + mdev->intr_ops->program_msi_to_src_map(mdev, + entry, offset, true); + cookie = MK_COOKIE(entry, offset); + dev_dbg(&mdev->pdev->dev, "irq: %d assigned for src: %d\n", + msix->vector, intr_src); + } else { + intr_cb = mic_register_intr_callback(mdev, offset, handler, + thread_fn, data); + if (IS_ERR(intr_cb)) { + dev_err(&mdev->pdev->dev, + "No available callback entries for use\n"); + rc = PTR_ERR(intr_cb); + goto err; + } + + entry = 0; + if (pci_dev_msi_enabled(pdev)) { + mdev->irq_info.mic_msi_map[entry] |= (1 << offset); + mdev->intr_ops->program_msi_to_src_map(mdev, + entry, offset, true); + } + cookie = MK_COOKIE(entry, intr_cb->cb_id); + dev_dbg(&mdev->pdev->dev, "callback %d registered for src: %d\n", + intr_cb->cb_id, intr_src); + } + return (struct mic_irq *)cookie; +err: + return ERR_PTR(rc); +} + +/** + * mic_free_irq - free irq. mic_mutex + * needs to be held before calling this function. + * + * @mdev: pointer to mic_device instance + * @cookie: cookie obtained during a successful call to mic_request_threaded_irq + * @data: private data specified by the calling function during the + * mic_request_threaded_irq + * + * returns: none. + */ +void mic_free_irq(struct mic_device *mdev, + struct mic_irq *cookie, void *data) +{ + u32 offset; + u32 entry; + u8 src_id; + unsigned int irq; + struct pci_dev *pdev = mdev->pdev; + + entry = GET_ENTRY((unsigned long)cookie); + offset = GET_OFFSET((unsigned long)cookie); + if (mdev->irq_info.num_vectors > 1) { + if (entry >= mdev->irq_info.num_vectors) { + dev_warn(&mdev->pdev->dev, + "entry %d should be < num_irq %d\n", + entry, mdev->irq_info.num_vectors); + return; + } + irq = mdev->irq_info.msix_entries[entry].vector; + free_irq(irq, data); + mdev->irq_info.mic_msi_map[entry] &= ~(BIT(offset)); + mdev->intr_ops->program_msi_to_src_map(mdev, + entry, offset, false); + + dev_dbg(&mdev->pdev->dev, "irq: %d freed\n", irq); + } else { + irq = pdev->irq; + src_id = mic_unregister_intr_callback(mdev, offset); + if (src_id >= MIC_NUM_OFFSETS) { + dev_warn(&mdev->pdev->dev, "Error unregistering callback\n"); + return; + } + if (pci_dev_msi_enabled(pdev)) { + mdev->irq_info.mic_msi_map[entry] &= ~(BIT(src_id)); + mdev->intr_ops->program_msi_to_src_map(mdev, + entry, src_id, false); + } + dev_dbg(&mdev->pdev->dev, "callback %d unregistered for src: %d\n", + offset, src_id); + } +} + +/** + * mic_setup_interrupts - Initializes interrupts. + * + * @mdev: pointer to mic_device instance + * @pdev: PCI device structure + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +int mic_setup_interrupts(struct mic_device *mdev, struct pci_dev *pdev) +{ + int rc; + + rc = mic_setup_msix(mdev, pdev); + if (!rc) + goto done; + + rc = mic_setup_msi(mdev, pdev); + if (!rc) + goto done; + + rc = mic_setup_intx(mdev, pdev); + if (rc) { + dev_err(&mdev->pdev->dev, "no usable interrupts\n"); + return rc; + } +done: + mdev->intr_ops->enable_interrupts(mdev); + return 0; +} + +/** + * mic_free_interrupts - Frees interrupts setup by mic_setup_interrupts + * + * @mdev: pointer to mic_device instance + * @pdev: PCI device structure + * + * returns none. + */ +void mic_free_interrupts(struct mic_device *mdev, struct pci_dev *pdev) +{ + int i; + + mdev->intr_ops->disable_interrupts(mdev); + if (mdev->irq_info.num_vectors > 1) { + for (i = 0; i < mdev->irq_info.num_vectors; i++) { + if (mdev->irq_info.mic_msi_map[i]) + dev_warn(&pdev->dev, "irq %d may still be in use.\n", + mdev->irq_info.msix_entries[i].vector); + } + kfree(mdev->irq_info.mic_msi_map); + kfree(mdev->irq_info.msix_entries); + pci_disable_msix(pdev); + } else { + if (pci_dev_msi_enabled(pdev)) { + free_irq(pdev->irq, mdev); + kfree(mdev->irq_info.mic_msi_map); + pci_disable_msi(pdev); + } else { + free_irq(pdev->irq, mdev); + } + mic_release_callbacks(mdev); + } +} + +/** + * mic_intr_restore - Restore MIC interrupt registers. + * + * @mdev: pointer to mic_device instance. + * + * Restore the interrupt registers to values previously + * stored in the SW data structures. mic_mutex needs to + * be held before calling this function. + * + * returns None. + */ +void mic_intr_restore(struct mic_device *mdev) +{ + int entry, offset; + struct pci_dev *pdev = mdev->pdev; + + if (!pci_dev_msi_enabled(pdev)) + return; + + for (entry = 0; entry < mdev->irq_info.num_vectors; entry++) { + for (offset = 0; offset < MIC_NUM_OFFSETS; offset++) { + if (mdev->irq_info.mic_msi_map[entry] & BIT(offset)) + mdev->intr_ops->program_msi_to_src_map(mdev, + entry, offset, true); + } + } +} |