OSCL-LXR linux-6.0.1/​drivers/​virt/​nitro_enclaves/​ne_pci_dev.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright 2020-2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
  */
 
 /**
  * DOC: Nitro Enclaves (NE) PCI device driver.
  */
 
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/nitro_enclaves.h>
 #include <linux/pci.h>
 #include <linux/types.h>
 #include <linux/wait.h>
 
 #include "ne_misc_dev.h"
 #include "ne_pci_dev.h"
 
 /**
  * NE_DEFAULT_TIMEOUT_MSECS - Default timeout to wait for a reply from
  *                the NE PCI device.
  */
 #define NE_DEFAULT_TIMEOUT_MSECS    (120000) /* 120 sec */
 
 static const struct pci_device_id ne_pci_ids[] = {
     { PCI_DEVICE(PCI_VENDOR_ID_AMAZON, PCI_DEVICE_ID_NE) },
     { 0, }
 };
 
 MODULE_DEVICE_TABLE(pci, ne_pci_ids);
 
 /**
  * ne_submit_request() - Submit command request to the PCI device based on the
  *           command type.
  * @pdev:       PCI device to send the command to.
  * @cmd_type:       Command type of the request sent to the PCI device.
  * @cmd_request:    Command request payload.
  * @cmd_request_size:   Size of the command request payload.
  *
  * Context: Process context. This function is called with the ne_pci_dev mutex held.
  */
 static void ne_submit_request(struct pci_dev *pdev, enum ne_pci_dev_cmd_type cmd_type,
                   void *cmd_request, size_t cmd_request_size)
 {
     struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
 
     memcpy_toio(ne_pci_dev->iomem_base + NE_SEND_DATA, cmd_request, cmd_request_size);
 
     iowrite32(cmd_type, ne_pci_dev->iomem_base + NE_COMMAND);
 }
 
 /**
  * ne_retrieve_reply() - Retrieve reply from the PCI device.
  * @pdev:       PCI device to receive the reply from.
  * @cmd_reply:      Command reply payload.
  * @cmd_reply_size: Size of the command reply payload.
  *
  * Context: Process context. This function is called with the ne_pci_dev mutex held.
  */
 static void ne_retrieve_reply(struct pci_dev *pdev, struct ne_pci_dev_cmd_reply *cmd_reply,
                   size_t cmd_reply_size)
 {
     struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
 
     memcpy_fromio(cmd_reply, ne_pci_dev->iomem_base + NE_RECV_DATA, cmd_reply_size);
 }
 
 /**
  * ne_wait_for_reply() - Wait for a reply of a PCI device command.
  * @pdev:   PCI device for which a reply is waited.
  *
  * Context: Process context. This function is called with the ne_pci_dev mutex held.
  * Return:
  * * 0 on success.
  * * Negative return value on failure.
  */
 static int ne_wait_for_reply(struct pci_dev *pdev)
 {
     struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
     int rc = -EINVAL;
 
     /*
      * TODO: Update to _interruptible and handle interrupted wait event
      * e.g. -ERESTARTSYS, incoming signals + update timeout, if needed.
      */
     rc = wait_event_timeout(ne_pci_dev->cmd_reply_wait_q,
                 atomic_read(&ne_pci_dev->cmd_reply_avail) != 0,
                 msecs_to_jiffies(NE_DEFAULT_TIMEOUT_MSECS));
     if (!rc)
         return -ETIMEDOUT;
 
     return 0;
 }
 
 int ne_do_request(struct pci_dev *pdev, enum ne_pci_dev_cmd_type cmd_type,
           void *cmd_request, size_t cmd_request_size,
           struct ne_pci_dev_cmd_reply *cmd_reply, size_t cmd_reply_size)
 {
     struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
     int rc = -EINVAL;
 
     if (cmd_type <= INVALID_CMD || cmd_type >= MAX_CMD) {
         dev_err_ratelimited(&pdev->dev, "Invalid cmd type=%u\n", cmd_type);
 
         return -EINVAL;
     }
 
     if (!cmd_request) {
         dev_err_ratelimited(&pdev->dev, "Null cmd request for cmd type=%u\n",
                     cmd_type);
 
         return -EINVAL;
     }
 
     if (cmd_request_size > NE_SEND_DATA_SIZE) {
         dev_err_ratelimited(&pdev->dev, "Invalid req size=%zu for cmd type=%u\n",
                     cmd_request_size, cmd_type);
 
         return -EINVAL;
     }
 
     if (!cmd_reply) {
         dev_err_ratelimited(&pdev->dev, "Null cmd reply for cmd type=%u\n",
                     cmd_type);
 
         return -EINVAL;
     }
 
     if (cmd_reply_size > NE_RECV_DATA_SIZE) {
         dev_err_ratelimited(&pdev->dev, "Invalid reply size=%zu for cmd type=%u\n",
                     cmd_reply_size, cmd_type);
 
         return -EINVAL;
     }
 
     /*
      * Use this mutex so that the PCI device handles one command request at
      * a time.
      */
     mutex_lock(&ne_pci_dev->pci_dev_mutex);
 
     atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
 
     ne_submit_request(pdev, cmd_type, cmd_request, cmd_request_size);
 
     rc = ne_wait_for_reply(pdev);
     if (rc < 0) {
         dev_err_ratelimited(&pdev->dev, "Error in wait for reply for cmd type=%u [rc=%d]\n",
                     cmd_type, rc);
 
         goto unlock_mutex;
     }
 
     ne_retrieve_reply(pdev, cmd_reply, cmd_reply_size);
 
     atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
 
     if (cmd_reply->rc < 0) {
         rc = cmd_reply->rc;
 
         dev_err_ratelimited(&pdev->dev, "Error in cmd process logic, cmd type=%u [rc=%d]\n",
                     cmd_type, rc);
 
         goto unlock_mutex;
     }
 
     rc = 0;
 
 unlock_mutex:
     mutex_unlock(&ne_pci_dev->pci_dev_mutex);
 
     return rc;
 }
 
 /**
  * ne_reply_handler() - Interrupt handler for retrieving a reply matching a
  *          request sent to the PCI device for enclave lifetime
  *          management.
  * @irq:    Received interrupt for a reply sent by the PCI device.
  * @args:   PCI device private data structure.
  *
  * Context: Interrupt context.
  * Return:
  * * IRQ_HANDLED on handled interrupt.
  */
 static irqreturn_t ne_reply_handler(int irq, void *args)
 {
     struct ne_pci_dev *ne_pci_dev = (struct ne_pci_dev *)args;
 
     atomic_set(&ne_pci_dev->cmd_reply_avail, 1);
 
     /* TODO: Update to _interruptible. */
     wake_up(&ne_pci_dev->cmd_reply_wait_q);
 
     return IRQ_HANDLED;
 }
 
 /**
  * ne_event_work_handler() - Work queue handler for notifying enclaves on a
  *               state change received by the event interrupt
  *               handler.
  * @work:   Item containing the NE PCI device for which an out-of-band event
  *      was issued.
  *
  * An out-of-band event is being issued by the Nitro Hypervisor when at least
  * one enclave is changing state without client interaction.
  *
  * Context: Work queue context.
  */
 static void ne_event_work_handler(struct work_struct *work)
 {
     struct ne_pci_dev_cmd_reply cmd_reply = {};
     struct ne_enclave *ne_enclave = NULL;
     struct ne_pci_dev *ne_pci_dev =
         container_of(work, struct ne_pci_dev, notify_work);
     struct pci_dev *pdev = ne_pci_dev->pdev;
     int rc = -EINVAL;
     struct slot_info_req slot_info_req = {};
 
     mutex_lock(&ne_pci_dev->enclaves_list_mutex);
 
     /*
      * Iterate over all enclaves registered for the Nitro Enclaves
      * PCI device and determine for which enclave(s) the out-of-band event
      * is corresponding to.
      */
     list_for_each_entry(ne_enclave, &ne_pci_dev->enclaves_list, enclave_list_entry) {
         mutex_lock(&ne_enclave->enclave_info_mutex);
 
         /*
          * Enclaves that were never started cannot receive out-of-band
          * events.
          */
         if (ne_enclave->state != NE_STATE_RUNNING)
             goto unlock;
 
         slot_info_req.slot_uid = ne_enclave->slot_uid;
 
         rc = ne_do_request(pdev, SLOT_INFO,
                    &slot_info_req, sizeof(slot_info_req),
                    &cmd_reply, sizeof(cmd_reply));
         if (rc < 0)
             dev_err(&pdev->dev, "Error in slot info [rc=%d]\n", rc);
 
         /* Notify enclave process that the enclave state changed. */
         if (ne_enclave->state != cmd_reply.state) {
             ne_enclave->state = cmd_reply.state;
 
             ne_enclave->has_event = true;
 
             wake_up_interruptible(&ne_enclave->eventq);
         }
 
 unlock:
          mutex_unlock(&ne_enclave->enclave_info_mutex);
     }
 
     mutex_unlock(&ne_pci_dev->enclaves_list_mutex);
 }
 
 /**
  * ne_event_handler() - Interrupt handler for PCI device out-of-band events.
  *          This interrupt does not supply any data in the MMIO
  *          region. It notifies a change in the state of any of
  *          the launched enclaves.
  * @irq:    Received interrupt for an out-of-band event.
  * @args:   PCI device private data structure.
  *
  * Context: Interrupt context.
  * Return:
  * * IRQ_HANDLED on handled interrupt.
  */
 static irqreturn_t ne_event_handler(int irq, void *args)
 {
     struct ne_pci_dev *ne_pci_dev = (struct ne_pci_dev *)args;
 
     queue_work(ne_pci_dev->event_wq, &ne_pci_dev->notify_work);
 
     return IRQ_HANDLED;
 }
 
 /**
  * ne_setup_msix() - Setup MSI-X vectors for the PCI device.
  * @pdev:   PCI device to setup the MSI-X for.
  *
  * Context: Process context.
  * Return:
  * * 0 on success.
  * * Negative return value on failure.
  */
 static int ne_setup_msix(struct pci_dev *pdev)
 {
     struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
     int nr_vecs = 0;
     int rc = -EINVAL;
 
     nr_vecs = pci_msix_vec_count(pdev);
     if (nr_vecs < 0) {
         rc = nr_vecs;
 
         dev_err(&pdev->dev, "Error in getting vec count [rc=%d]\n", rc);
 
         return rc;
     }
 
     rc = pci_alloc_irq_vectors(pdev, nr_vecs, nr_vecs, PCI_IRQ_MSIX);
     if (rc < 0) {
         dev_err(&pdev->dev, "Error in alloc MSI-X vecs [rc=%d]\n", rc);
 
         return rc;
     }
 
     /*
      * This IRQ gets triggered every time the PCI device responds to a
      * command request. The reply is then retrieved, reading from the MMIO
      * space of the PCI device.
      */
     rc = request_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_reply_handler,
              0, "enclave_cmd", ne_pci_dev);
     if (rc < 0) {
         dev_err(&pdev->dev, "Error in request irq reply [rc=%d]\n", rc);
 
         goto free_irq_vectors;
     }
 
     ne_pci_dev->event_wq = create_singlethread_workqueue("ne_pci_dev_wq");
     if (!ne_pci_dev->event_wq) {
         rc = -ENOMEM;
 
         dev_err(&pdev->dev, "Cannot get wq for dev events [rc=%d]\n", rc);
 
         goto free_reply_irq_vec;
     }
 
     INIT_WORK(&ne_pci_dev->notify_work, ne_event_work_handler);
 
     /*
      * This IRQ gets triggered every time any enclave's state changes. Its
      * handler then scans for the changes and propagates them to the user
      * space.
      */
     rc = request_irq(pci_irq_vector(pdev, NE_VEC_EVENT), ne_event_handler,
              0, "enclave_evt", ne_pci_dev);
     if (rc < 0) {
         dev_err(&pdev->dev, "Error in request irq event [rc=%d]\n", rc);
 
         goto destroy_wq;
     }
 
     return 0;
 
 destroy_wq:
     destroy_workqueue(ne_pci_dev->event_wq);
 free_reply_irq_vec:
     free_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_pci_dev);
 free_irq_vectors:
     pci_free_irq_vectors(pdev);
 
     return rc;
 }
 
 /**
  * ne_teardown_msix() - Teardown MSI-X vectors for the PCI device.
  * @pdev:   PCI device to teardown the MSI-X for.
  *
  * Context: Process context.
  */
 static void ne_teardown_msix(struct pci_dev *pdev)
 {
     struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
 
     free_irq(pci_irq_vector(pdev, NE_VEC_EVENT), ne_pci_dev);
 
     flush_work(&ne_pci_dev->notify_work);
     destroy_workqueue(ne_pci_dev->event_wq);
 
     free_irq(pci_irq_vector(pdev, NE_VEC_REPLY), ne_pci_dev);
 
     pci_free_irq_vectors(pdev);
 }
 
 /**
  * ne_pci_dev_enable() - Select the PCI device version and enable it.
  * @pdev:   PCI device to select version for and then enable.
  *
  * Context: Process context.
  * Return:
  * * 0 on success.
  * * Negative return value on failure.
  */
 static int ne_pci_dev_enable(struct pci_dev *pdev)
 {
     u8 dev_enable_reply = 0;
     u16 dev_version_reply = 0;
     struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
 
     iowrite16(NE_VERSION_MAX, ne_pci_dev->iomem_base + NE_VERSION);
 
     dev_version_reply = ioread16(ne_pci_dev->iomem_base + NE_VERSION);
     if (dev_version_reply != NE_VERSION_MAX) {
         dev_err(&pdev->dev, "Error in pci dev version cmd\n");
 
         return -EIO;
     }
 
     iowrite8(NE_ENABLE_ON, ne_pci_dev->iomem_base + NE_ENABLE);
 
     dev_enable_reply = ioread8(ne_pci_dev->iomem_base + NE_ENABLE);
     if (dev_enable_reply != NE_ENABLE_ON) {
         dev_err(&pdev->dev, "Error in pci dev enable cmd\n");
 
         return -EIO;
     }
 
     return 0;
 }
 
 /**
  * ne_pci_dev_disable() - Disable the PCI device.
  * @pdev:   PCI device to disable.
  *
  * Context: Process context.
  */
 static void ne_pci_dev_disable(struct pci_dev *pdev)
 {
     u8 dev_disable_reply = 0;
     struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
     const unsigned int sleep_time = 10; /* 10 ms */
     unsigned int sleep_time_count = 0;
 
     iowrite8(NE_ENABLE_OFF, ne_pci_dev->iomem_base + NE_ENABLE);
 
     /*
      * Check for NE_ENABLE_OFF in a loop, to handle cases when the device
      * state is not immediately set to disabled and going through a
      * transitory state of disabling.
      */
     while (sleep_time_count < NE_DEFAULT_TIMEOUT_MSECS) {
         dev_disable_reply = ioread8(ne_pci_dev->iomem_base + NE_ENABLE);
         if (dev_disable_reply == NE_ENABLE_OFF)
             return;
 
         msleep_interruptible(sleep_time);
         sleep_time_count += sleep_time;
     }
 
     dev_disable_reply = ioread8(ne_pci_dev->iomem_base + NE_ENABLE);
     if (dev_disable_reply != NE_ENABLE_OFF)
         dev_err(&pdev->dev, "Error in pci dev disable cmd\n");
 }
 
 /**
  * ne_pci_probe() - Probe function for the NE PCI device.
  * @pdev:   PCI device to match with the NE PCI driver.
  * @id :    PCI device id table associated with the NE PCI driver.
  *
  * Context: Process context.
  * Return:
  * * 0 on success.
  * * Negative return value on failure.
  */
 static int ne_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
     struct ne_pci_dev *ne_pci_dev = NULL;
     int rc = -EINVAL;
 
     ne_pci_dev = kzalloc(sizeof(*ne_pci_dev), GFP_KERNEL);
     if (!ne_pci_dev)
         return -ENOMEM;
 
     rc = pci_enable_device(pdev);
     if (rc < 0) {
         dev_err(&pdev->dev, "Error in pci dev enable [rc=%d]\n", rc);
 
         goto free_ne_pci_dev;
     }
 
     pci_set_master(pdev);
 
     rc = pci_request_regions_exclusive(pdev, "nitro_enclaves");
     if (rc < 0) {
         dev_err(&pdev->dev, "Error in pci request regions [rc=%d]\n", rc);
 
         goto disable_pci_dev;
     }
 
     ne_pci_dev->iomem_base = pci_iomap(pdev, PCI_BAR_NE, 0);
     if (!ne_pci_dev->iomem_base) {
         rc = -ENOMEM;
 
         dev_err(&pdev->dev, "Error in pci iomap [rc=%d]\n", rc);
 
         goto release_pci_regions;
     }
 
     pci_set_drvdata(pdev, ne_pci_dev);
 
     rc = ne_setup_msix(pdev);
     if (rc < 0) {
         dev_err(&pdev->dev, "Error in pci dev msix setup [rc=%d]\n", rc);
 
         goto iounmap_pci_bar;
     }
 
     ne_pci_dev_disable(pdev);
 
     rc = ne_pci_dev_enable(pdev);
     if (rc < 0) {
         dev_err(&pdev->dev, "Error in ne_pci_dev enable [rc=%d]\n", rc);
 
         goto teardown_msix;
     }
 
     atomic_set(&ne_pci_dev->cmd_reply_avail, 0);
     init_waitqueue_head(&ne_pci_dev->cmd_reply_wait_q);
     INIT_LIST_HEAD(&ne_pci_dev->enclaves_list);
     mutex_init(&ne_pci_dev->enclaves_list_mutex);
     mutex_init(&ne_pci_dev->pci_dev_mutex);
     ne_pci_dev->pdev = pdev;
 
     ne_devs.ne_pci_dev = ne_pci_dev;
 
     rc = misc_register(ne_devs.ne_misc_dev);
     if (rc < 0) {
         dev_err(&pdev->dev, "Error in misc dev register [rc=%d]\n", rc);
 
         goto disable_ne_pci_dev;
     }
 
     return 0;
 
 disable_ne_pci_dev:
     ne_devs.ne_pci_dev = NULL;
     ne_pci_dev_disable(pdev);
 teardown_msix:
     ne_teardown_msix(pdev);
 iounmap_pci_bar:
     pci_set_drvdata(pdev, NULL);
     pci_iounmap(pdev, ne_pci_dev->iomem_base);
 release_pci_regions:
     pci_release_regions(pdev);
 disable_pci_dev:
     pci_disable_device(pdev);
 free_ne_pci_dev:
     kfree(ne_pci_dev);
 
     return rc;
 }
 
 /**
  * ne_pci_remove() - Remove function for the NE PCI device.
  * @pdev:   PCI device associated with the NE PCI driver.
  *
  * Context: Process context.
  */
 static void ne_pci_remove(struct pci_dev *pdev)
 {
     struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
 
     misc_deregister(ne_devs.ne_misc_dev);
 
     ne_devs.ne_pci_dev = NULL;
 
     ne_pci_dev_disable(pdev);
 
     ne_teardown_msix(pdev);
 
     pci_set_drvdata(pdev, NULL);
 
     pci_iounmap(pdev, ne_pci_dev->iomem_base);
 
     pci_release_regions(pdev);
 
     pci_disable_device(pdev);
 
     kfree(ne_pci_dev);
 }
 
 /**
  * ne_pci_shutdown() - Shutdown function for the NE PCI device.
  * @pdev:   PCI device associated with the NE PCI driver.
  *
  * Context: Process context.
  */
 static void ne_pci_shutdown(struct pci_dev *pdev)
 {
     struct ne_pci_dev *ne_pci_dev = pci_get_drvdata(pdev);
 
     if (!ne_pci_dev)
         return;
 
     misc_deregister(ne_devs.ne_misc_dev);
 
     ne_devs.ne_pci_dev = NULL;
 
     ne_pci_dev_disable(pdev);
 
     ne_teardown_msix(pdev);
 
     pci_set_drvdata(pdev, NULL);
 
     pci_iounmap(pdev, ne_pci_dev->iomem_base);
 
     pci_release_regions(pdev);
 
     pci_disable_device(pdev);
 
     kfree(ne_pci_dev);
 }
 
 /*
  * TODO: Add suspend / resume functions for power management w/ CONFIG_PM, if
  * needed.
  */
 /* NE PCI device driver. */
 struct pci_driver ne_pci_driver = {
     .name       = "nitro_enclaves",
     .id_table   = ne_pci_ids,
     .probe      = ne_pci_probe,
     .remove     = ne_pci_remove,
     .shutdown   = ne_pci_shutdown,
 };

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