// SPDX-License-Identifier: GPL-2.0 OR MIT
/*
 * Copyright 2020-2022 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include <linux/poll.h>
#include <linux/wait.h>
#include <linux/anon_inodes.h>
#include <uapi/linux/kfd_ioctl.h>
#include "amdgpu.h"
#include "amdgpu_vm.h"
#include "kfd_priv.h"
#include "kfd_smi_events.h"
#include "amdgpu_reset.h"

struct kfd_smi_client {
        struct list_head list;
        struct kfifo fifo;
        wait_queue_head_t wait_queue;
        /* events enabled */
        uint64_t events;
        struct kfd_node *dev;
        spinlock_t lock;
        struct rcu_head rcu;
        pid_t pid;
        bool suser;
};

#define KFD_MAX_KFIFO_SIZE      8192

static __poll_t kfd_smi_ev_poll(struct file *, struct poll_table_struct *);
static ssize_t kfd_smi_ev_read(struct file *, char __user *, size_t, loff_t *);
static ssize_t kfd_smi_ev_write(struct file *, const char __user *, size_t,
                                loff_t *);
static int kfd_smi_ev_release(struct inode *, struct file *);

static const char kfd_smi_name[] = "kfd_smi_ev";

static const struct file_operations kfd_smi_ev_fops = {
        .owner = THIS_MODULE,
        .poll = kfd_smi_ev_poll,
        .read = kfd_smi_ev_read,
        .write = kfd_smi_ev_write,
        .release = kfd_smi_ev_release
};

static __poll_t kfd_smi_ev_poll(struct file *filep,
                                struct poll_table_struct *wait)
{
        struct kfd_smi_client *client = filep->private_data;
        __poll_t mask = 0;

        poll_wait(filep, &client->wait_queue, wait);

        spin_lock(&client->lock);
        if (!kfifo_is_empty(&client->fifo))
                mask = EPOLLIN | EPOLLRDNORM;
        spin_unlock(&client->lock);

        return mask;
}

static ssize_t kfd_smi_ev_read(struct file *filep, char __user *user,
                               size_t size, loff_t *offset)
{
        int ret;
        size_t to_copy;
        struct kfd_smi_client *client = filep->private_data;
        unsigned char *buf;

        size = min_t(size_t, size, KFD_MAX_KFIFO_SIZE);
        buf = kmalloc(size, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        /* kfifo_to_user can sleep so we can't use spinlock protection around
         * it. Instead, we kfifo out as spinlocked then copy them to the user.
         */
        spin_lock(&client->lock);
        to_copy = kfifo_len(&client->fifo);
        if (!to_copy) {
                spin_unlock(&client->lock);
                ret = -EAGAIN;
                goto ret_err;
        }
        to_copy = min(size, to_copy);
        ret = kfifo_out(&client->fifo, buf, to_copy);
        spin_unlock(&client->lock);
        if (ret <= 0) {
                ret = -EAGAIN;
                goto ret_err;
        }

        ret = copy_to_user(user, buf, to_copy);
        if (ret) {
                ret = -EFAULT;
                goto ret_err;
        }

        kfree(buf);
        return to_copy;

ret_err:
        kfree(buf);
        return ret;
}

static ssize_t kfd_smi_ev_write(struct file *filep, const char __user *user,
                                size_t size, loff_t *offset)
{
        struct kfd_smi_client *client = filep->private_data;
        uint64_t events;

        if (!access_ok(user, size) || size < sizeof(events))
                return -EFAULT;
        if (copy_from_user(&events, user, sizeof(events)))
                return -EFAULT;

        WRITE_ONCE(client->events, events);

        return sizeof(events);
}

static void kfd_smi_ev_client_free(struct rcu_head *p)
{
        struct kfd_smi_client *ev = container_of(p, struct kfd_smi_client, rcu);

        kfifo_free(&ev->fifo);
        kfree(ev);
}

static int kfd_smi_ev_release(struct inode *inode, struct file *filep)
{
        struct kfd_smi_client *client = filep->private_data;
        struct kfd_node *dev = client->dev;

        spin_lock(&dev->smi_lock);
        list_del_rcu(&client->list);
        spin_unlock(&dev->smi_lock);

        call_rcu(&client->rcu, kfd_smi_ev_client_free);
        return 0;
}

static bool kfd_smi_ev_enabled(pid_t pid, struct kfd_smi_client *client,
                               unsigned int event)
{
        uint64_t events = READ_ONCE(client->events);

        if (pid && client->pid != pid && !client->suser)
                return false;

        return events & KFD_SMI_EVENT_MASK_FROM_INDEX(event);
}

static void add_event_to_kfifo(pid_t pid, struct kfd_node *dev,
                               unsigned int smi_event, char *event_msg, int len)
{
        struct kfd_smi_client *client;

        rcu_read_lock();

        list_for_each_entry_rcu(client, &dev->smi_clients, list) {
                if (!kfd_smi_ev_enabled(pid, client, smi_event))
                        continue;
                spin_lock(&client->lock);
                if (kfifo_avail(&client->fifo) >= len) {
                        kfifo_in(&client->fifo, event_msg, len);
                        wake_up_all(&client->wait_queue);
                } else {
                        pr_debug("smi_event(EventID: %u): no space left\n",
                                        smi_event);
                }
                spin_unlock(&client->lock);
        }

        rcu_read_unlock();
}

__printf(4, 5)
static void kfd_smi_event_add(pid_t pid, struct kfd_node *dev,
                              unsigned int event, char *fmt, ...)
{
        char fifo_in[KFD_SMI_EVENT_MSG_SIZE];
        int len;
        va_list args;

        if (list_empty(&dev->smi_clients))
                return;

        len = snprintf(fifo_in, sizeof(fifo_in), "%x ", event);

        va_start(args, fmt);
        len += vsnprintf(fifo_in + len, sizeof(fifo_in) - len, fmt, args);
        va_end(args);

        add_event_to_kfifo(pid, dev, event, fifo_in, len);
}

void kfd_smi_event_update_gpu_reset(struct kfd_node *dev, bool post_reset,
                                    struct amdgpu_reset_context *reset_context)
{
        unsigned int event;
        char reset_cause[64];

        if (post_reset) {
                event = KFD_SMI_EVENT_GPU_POST_RESET;
        } else {
                event = KFD_SMI_EVENT_GPU_PRE_RESET;
                ++(dev->reset_seq_num);
        }

        memset(reset_cause, 0, sizeof(reset_cause));

        if (reset_context)
                amdgpu_reset_get_desc(reset_context, reset_cause,
                                      sizeof(reset_cause));

        kfd_smi_event_add(0, dev, event, KFD_EVENT_FMT_UPDATE_GPU_RESET(
                          dev->reset_seq_num, reset_cause));
}

void kfd_smi_event_update_thermal_throttling(struct kfd_node *dev,
                                             uint64_t throttle_bitmask)
{
        kfd_smi_event_add(0, dev, KFD_SMI_EVENT_THERMAL_THROTTLE, KFD_EVENT_FMT_THERMAL_THROTTLING(
                          throttle_bitmask,
                          amdgpu_dpm_get_thermal_throttling_counter(dev->adev)));
}

void kfd_smi_event_update_vmfault(struct kfd_node *dev, uint16_t pasid)
{
        struct amdgpu_task_info *task_info;

        task_info = amdgpu_vm_get_task_info_pasid(dev->adev, pasid);
        if (task_info) {
                /* Report VM faults from user applications, not retry from kernel */
                if (task_info->task.pid)
                        kfd_smi_event_add(0, dev, KFD_SMI_EVENT_VMFAULT, KFD_EVENT_FMT_VMFAULT(
                                          task_info->task.pid, task_info->task.comm));
                amdgpu_vm_put_task_info(task_info);
        }
}

void kfd_smi_event_page_fault_start(struct kfd_node *node, pid_t pid,
                                    unsigned long address, bool write_fault,
                                    ktime_t ts)
{
        kfd_smi_event_add(pid, node, KFD_SMI_EVENT_PAGE_FAULT_START,
                          KFD_EVENT_FMT_PAGEFAULT_START(ktime_to_ns(ts), pid,
                          address, node->id, write_fault ? 'W' : 'R'));
}

void kfd_smi_event_page_fault_end(struct kfd_node *node, pid_t pid,
                                  unsigned long address, bool migration)
{
        kfd_smi_event_add(pid, node, KFD_SMI_EVENT_PAGE_FAULT_END,
                          KFD_EVENT_FMT_PAGEFAULT_END(ktime_get_boottime_ns(),
                          pid, address, node->id, migration ? 'M' : 'U'));
}

void kfd_smi_event_migration_start(struct kfd_node *node, pid_t pid,
                                   unsigned long start, unsigned long end,
                                   uint32_t from, uint32_t to,
                                   uint32_t prefetch_loc, uint32_t preferred_loc,
                                   uint32_t trigger)
{
        kfd_smi_event_add(pid, node, KFD_SMI_EVENT_MIGRATE_START,
                          KFD_EVENT_FMT_MIGRATE_START(
                          ktime_get_boottime_ns(), pid, start, end - start,
                          from, to, prefetch_loc, preferred_loc, trigger));
}

void kfd_smi_event_migration_end(struct kfd_node *node, pid_t pid,
                                 unsigned long start, unsigned long end,
                                 uint32_t from, uint32_t to, uint32_t trigger,
                                 int error_code)
{
        kfd_smi_event_add(pid, node, KFD_SMI_EVENT_MIGRATE_END,
                          KFD_EVENT_FMT_MIGRATE_END(
                          ktime_get_boottime_ns(), pid, start, end - start,
                          from, to, trigger, error_code));
}

void kfd_smi_event_queue_eviction(struct kfd_node *node, pid_t pid,
                                  uint32_t trigger)
{
        kfd_smi_event_add(pid, node, KFD_SMI_EVENT_QUEUE_EVICTION,
                          KFD_EVENT_FMT_QUEUE_EVICTION(ktime_get_boottime_ns(), pid,
                          node->id, trigger));
}

void kfd_smi_event_queue_restore(struct kfd_node *node, pid_t pid)
{
        kfd_smi_event_add(pid, node, KFD_SMI_EVENT_QUEUE_RESTORE,
                          KFD_EVENT_FMT_QUEUE_RESTORE(ktime_get_boottime_ns(), pid,
                          node->id, '0'));
}

void kfd_smi_event_queue_restore_rescheduled(struct mm_struct *mm)
{
        struct kfd_process *p;
        int i;

        p = kfd_lookup_process_by_mm(mm);
        if (!p)
                return;

        for (i = 0; i < p->n_pdds; i++) {
                struct kfd_process_device *pdd = p->pdds[i];

                kfd_smi_event_add(p->lead_thread->pid, pdd->dev,
                                  KFD_SMI_EVENT_QUEUE_RESTORE,
                                  KFD_EVENT_FMT_QUEUE_RESTORE(ktime_get_boottime_ns(),
                                  p->lead_thread->pid, pdd->dev->id, 'R'));
        }
        kfd_unref_process(p);
}

void kfd_smi_event_unmap_from_gpu(struct kfd_node *node, pid_t pid,
                                  unsigned long address, unsigned long last,
                                  uint32_t trigger)
{
        kfd_smi_event_add(pid, node, KFD_SMI_EVENT_UNMAP_FROM_GPU,
                          KFD_EVENT_FMT_UNMAP_FROM_GPU(ktime_get_boottime_ns(),
                          pid, address, last - address + 1, node->id, trigger));
}

void kfd_smi_event_process(struct kfd_process_device *pdd, bool start)
{
        struct amdgpu_task_info *task_info;
        struct amdgpu_vm *avm;

        if (!pdd->drm_priv)
                return;

        avm = drm_priv_to_vm(pdd->drm_priv);
        task_info = amdgpu_vm_get_task_info_vm(avm);

        if (task_info) {
                kfd_smi_event_add(0, pdd->dev,
                                  start ? KFD_SMI_EVENT_PROCESS_START :
                                  KFD_SMI_EVENT_PROCESS_END,
                                  KFD_EVENT_FMT_PROCESS(task_info->task.pid,
                                  task_info->task.comm));
                amdgpu_vm_put_task_info(task_info);
        }
}

int kfd_smi_event_open(struct kfd_node *dev, uint32_t *fd)
{
        struct kfd_smi_client *client;
        int ret;

        client = kzalloc_obj(struct kfd_smi_client);
        if (!client)
                return -ENOMEM;
        INIT_LIST_HEAD(&client->list);

        ret = kfifo_alloc(&client->fifo, KFD_MAX_KFIFO_SIZE, GFP_KERNEL);
        if (ret) {
                kfree(client);
                return ret;
        }

        init_waitqueue_head(&client->wait_queue);
        spin_lock_init(&client->lock);
        client->events = 0;
        client->dev = dev;
        client->pid = current->tgid;
        client->suser = capable(CAP_SYS_ADMIN);

        spin_lock(&dev->smi_lock);
        list_add_rcu(&client->list, &dev->smi_clients);
        spin_unlock(&dev->smi_lock);

        ret = anon_inode_getfd(kfd_smi_name, &kfd_smi_ev_fops, (void *)client,
                               O_RDWR);
        if (ret < 0) {
                spin_lock(&dev->smi_lock);
                list_del_rcu(&client->list);
                spin_unlock(&dev->smi_lock);

                synchronize_rcu();

                kfifo_free(&client->fifo);
                kfree(client);
                return ret;
        }
        *fd = ret;

        return 0;
}