f69bcbf3b4
This patch introduces the host "Virtio over PCIe" interface for Intel MIC. It allows creating user space backends on the host and instantiating virtio devices for them on the Intel MIC card. It uses the existing VRINGH infrastructure in the kernel to access virtio rings from the host. A character device per MIC is exposed with IOCTL, mmap and poll callbacks. This allows the user space backend to: (a) add/remove a virtio device via a device page. (b) map (R/O) virtio rings and device page to user space. (c) poll for availability of data. (d) copy a descriptor or entire descriptor chain to/from the card. (e) modify virtio configuration. (f) handle virtio device reset. The buffers are copied over using CPU copies for this initial patch and host initiated MIC DMA support is planned for future patches. The avail and desc virtio rings are in host memory and the used ring is in card memory to maximize writes across PCIe for performance. Co-author: Sudeep Dutt <sudeep.dutt@intel.com> Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com> Signed-off-by: Caz Yokoyama <Caz.Yokoyama@intel.com> Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com> Signed-off-by: Nikhil Rao <nikhil.rao@intel.com> Signed-off-by: Harshavardhan R Kharche <harshavardhan.r.kharche@intel.com> Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com> Acked-by: Yaozu (Eddie) Dong <eddie.dong@intel.com> Reviewed-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
186 lines
4.7 KiB
C
186 lines
4.7 KiB
C
/*
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* Intel MIC Platform Software Stack (MPSS)
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*
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* Copyright(c) 2013 Intel Corporation.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* The full GNU General Public License is included in this distribution in
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* the file called "COPYING".
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*
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* Intel MIC Host driver.
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*
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*/
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#include <linux/delay.h>
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#include <linux/firmware.h>
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#include <linux/mic_common.h>
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#include "../common/mic_device.h"
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#include "mic_device.h"
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#include "mic_smpt.h"
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#include "mic_virtio.h"
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/**
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* mic_reset - Reset the MIC device.
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* @mdev: pointer to mic_device instance
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*/
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static void mic_reset(struct mic_device *mdev)
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{
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int i;
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#define MIC_RESET_TO (45)
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mdev->ops->reset_fw_ready(mdev);
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mdev->ops->reset(mdev);
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for (i = 0; i < MIC_RESET_TO; i++) {
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if (mdev->ops->is_fw_ready(mdev))
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return;
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/*
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* Resets typically take 10s of seconds to complete.
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* Since an MMIO read is required to check if the
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* firmware is ready or not, a 1 second delay works nicely.
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*/
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msleep(1000);
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}
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mic_set_state(mdev, MIC_RESET_FAILED);
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}
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/* Initialize the MIC bootparams */
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void mic_bootparam_init(struct mic_device *mdev)
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{
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struct mic_bootparam *bootparam = mdev->dp;
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bootparam->magic = MIC_MAGIC;
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bootparam->c2h_shutdown_db = mdev->shutdown_db;
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bootparam->h2c_shutdown_db = -1;
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bootparam->h2c_config_db = -1;
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bootparam->shutdown_status = 0;
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bootparam->shutdown_card = 0;
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}
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/**
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* mic_start - Start the MIC.
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* @mdev: pointer to mic_device instance
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* @buf: buffer containing boot string including firmware/ramdisk path.
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*
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* This function prepares an MIC for boot and initiates boot.
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* RETURNS: An appropriate -ERRNO error value on error, or zero for success.
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*/
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int mic_start(struct mic_device *mdev, const char *buf)
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{
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int rc;
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mutex_lock(&mdev->mic_mutex);
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retry:
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if (MIC_OFFLINE != mdev->state) {
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rc = -EINVAL;
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goto unlock_ret;
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}
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if (!mdev->ops->is_fw_ready(mdev)) {
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mic_reset(mdev);
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/*
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* The state will either be MIC_OFFLINE if the reset succeeded
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* or MIC_RESET_FAILED if the firmware reset failed.
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*/
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goto retry;
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}
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rc = mdev->ops->load_mic_fw(mdev, buf);
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if (rc)
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goto unlock_ret;
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mic_smpt_restore(mdev);
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mic_intr_restore(mdev);
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mdev->intr_ops->enable_interrupts(mdev);
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mdev->ops->write_spad(mdev, MIC_DPLO_SPAD, mdev->dp_dma_addr);
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mdev->ops->write_spad(mdev, MIC_DPHI_SPAD, mdev->dp_dma_addr >> 32);
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mdev->ops->send_firmware_intr(mdev);
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mic_set_state(mdev, MIC_ONLINE);
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unlock_ret:
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mutex_unlock(&mdev->mic_mutex);
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return rc;
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}
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/**
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* mic_stop - Prepare the MIC for reset and trigger reset.
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* @mdev: pointer to mic_device instance
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* @force: force a MIC to reset even if it is already offline.
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*
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* RETURNS: None.
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*/
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void mic_stop(struct mic_device *mdev, bool force)
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{
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mutex_lock(&mdev->mic_mutex);
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if (MIC_OFFLINE != mdev->state || force) {
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mic_virtio_reset_devices(mdev);
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mic_bootparam_init(mdev);
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mic_reset(mdev);
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if (MIC_RESET_FAILED == mdev->state)
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goto unlock;
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mic_set_shutdown_status(mdev, MIC_NOP);
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mic_set_state(mdev, MIC_OFFLINE);
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}
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unlock:
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mutex_unlock(&mdev->mic_mutex);
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}
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/**
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* mic_shutdown - Initiate MIC shutdown.
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* @mdev: pointer to mic_device instance
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*
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* RETURNS: None.
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*/
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void mic_shutdown(struct mic_device *mdev)
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{
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struct mic_bootparam *bootparam = mdev->dp;
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s8 db = bootparam->h2c_shutdown_db;
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mutex_lock(&mdev->mic_mutex);
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if (MIC_ONLINE == mdev->state && db != -1) {
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bootparam->shutdown_card = 1;
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mdev->ops->send_intr(mdev, db);
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mic_set_state(mdev, MIC_SHUTTING_DOWN);
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}
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mutex_unlock(&mdev->mic_mutex);
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}
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/**
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* mic_shutdown_work - Handle shutdown interrupt from MIC.
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* @work: The work structure.
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*
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* This work is scheduled whenever the host has received a shutdown
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* interrupt from the MIC.
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*/
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void mic_shutdown_work(struct work_struct *work)
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{
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struct mic_device *mdev = container_of(work, struct mic_device,
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shutdown_work);
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struct mic_bootparam *bootparam = mdev->dp;
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mutex_lock(&mdev->mic_mutex);
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mic_set_shutdown_status(mdev, bootparam->shutdown_status);
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bootparam->shutdown_status = 0;
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if (MIC_SHUTTING_DOWN != mdev->state)
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mic_set_state(mdev, MIC_SHUTTING_DOWN);
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mutex_unlock(&mdev->mic_mutex);
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}
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/**
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* mic_reset_trigger_work - Trigger MIC reset.
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* @work: The work structure.
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*
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* This work is scheduled whenever the host wants to reset the MIC.
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*/
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void mic_reset_trigger_work(struct work_struct *work)
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{
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struct mic_device *mdev = container_of(work, struct mic_device,
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reset_trigger_work);
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mic_stop(mdev, false);
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}
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