/*-
 *   BSD LICENSE
 *
 *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <signal.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/epoll.h>
#include <sys/queue.h>
#include <sys/time.h>

#include <rte_log.h>
#include <rte_memory.h>
#include <rte_malloc.h>
#include <rte_atomic.h>
#include <rte_cycles.h>
#include <rte_ethdev.h>
#include <rte_pmd_i40e.h>

#include <libvirt/libvirt.h>
#include "channel_monitor.h"
#include "channel_commands.h"
#include "channel_manager.h"
#include "power_manager.h"

#define RTE_LOGTYPE_CHANNEL_MONITOR RTE_LOGTYPE_USER1

#define MAX_EVENTS 256

uint64_t vsi_pkt_count_prev[384];
uint64_t rdtsc_prev[384];

double time_period_s = 1;
static volatile unsigned run_loop = 1;
static int global_event_fd;
static unsigned int policy_is_set;
static struct epoll_event *global_events_list;
static struct policy policies[MAX_VMS];

void channel_monitor_exit(void)
{
	run_loop = 0;
	rte_free(global_events_list);
}

static void
core_share(int pNo, int z, int x, int t)
{
	if (policies[pNo].core_share[z].pcpu == lvm_info[x].pcpus[t]) {
		if (strcmp(policies[pNo].pkt.vm_name,
				lvm_info[x].vm_name) != 0) {
			policies[pNo].core_share[z].status = 1;
			power_manager_scale_core_max(
					policies[pNo].core_share[z].pcpu);
		}
	}
}

static void
core_share_status(int pNo)
{

	int noVms, noVcpus, z, x, t;

	get_all_vm(&noVms, &noVcpus);

	/* Reset Core Share Status. */
	for (z = 0; z < noVcpus; z++)
		policies[pNo].core_share[z].status = 0;

	/* Foreach vcpu in a policy. */
	for (z = 0; z < policies[pNo].pkt.num_vcpu; z++) {
		/* Foreach VM on the platform. */
		for (x = 0; x < noVms; x++) {
			/* Foreach vcpu of VMs on platform. */
			for (t = 0; t < lvm_info[x].num_cpus; t++)
				core_share(pNo, z, x, t);
		}
	}
}

static void
get_pcpu_to_control(struct policy *pol)
{

	/* Convert vcpu to pcpu. */
	struct vm_info info;
	int pcpu, count;
	uint64_t mask_u64b;

	RTE_LOG(INFO, CHANNEL_MONITOR, "Looking for pcpu for %s\n",
			pol->pkt.vm_name);
	get_info_vm(pol->pkt.vm_name, &info);

	for (count = 0; count < pol->pkt.num_vcpu; count++) {
		mask_u64b = info.pcpu_mask[pol->pkt.vcpu_to_control[count]];
		for (pcpu = 0; mask_u64b; mask_u64b &= ~(1ULL << pcpu++)) {
			if ((mask_u64b >> pcpu) & 1)
				pol->core_share[count].pcpu = pcpu;
		}
	}
}

static int
get_pfid(struct policy *pol)
{

	int i, x, ret = 0, nb_ports;

	nb_ports = rte_eth_dev_count();
	for (i = 0; i < pol->pkt.nb_mac_to_monitor; i++) {

		for (x = 0; x < nb_ports; x++) {
			ret = rte_pmd_i40e_query_vfid_by_mac(x,
				(struct ether_addr *)&(pol->pkt.vfid[i]));
			if (ret != -EINVAL) {
				pol->port[i] = x;
				break;
			}
		}
		if (ret == -EINVAL || ret == -ENOTSUP || ret == ENODEV) {
			RTE_LOG(INFO, CHANNEL_MONITOR,
				"Error with Policy. MAC not found on "
				"attached ports ");
			pol->enabled = 0;
			return ret;
		}
		pol->pfid[i] = ret;
	}
	return 1;
}

static int
update_policy(struct channel_packet *pkt)
{

	unsigned int updated = 0;
	int i;

	for (i = 0; i < MAX_VMS; i++) {
		if (strcmp(policies[i].pkt.vm_name, pkt->vm_name) == 0) {
			policies[i].pkt = *pkt;
			get_pcpu_to_control(&policies[i]);
			if (get_pfid(&policies[i]) == -1) {
				updated = 1;
				break;
			}
			core_share_status(i);
			policies[i].enabled = 1;
			updated = 1;
		}
	}
	if (!updated) {
		for (i = 0; i < MAX_VMS; i++) {
			if (policies[i].enabled == 0) {
				policies[i].pkt = *pkt;
				get_pcpu_to_control(&policies[i]);
				if (get_pfid(&policies[i]) == -1)
					break;
				core_share_status(i);
				policies[i].enabled = 1;
				break;
			}
		}
	}
	return 0;
}

static uint64_t
get_pkt_diff(struct policy *pol)
{

	uint64_t vsi_pkt_count,
		vsi_pkt_total = 0,
		vsi_pkt_count_prev_total = 0;
	double rdtsc_curr, rdtsc_diff, diff;
	int x;
	struct rte_eth_stats vf_stats;

	for (x = 0; x < pol->pkt.nb_mac_to_monitor; x++) {

		/*Read vsi stats*/
		if (rte_pmd_i40e_get_vf_stats(x, pol->pfid[x], &vf_stats) == 0)
			vsi_pkt_count = vf_stats.ipackets;
		else
			vsi_pkt_count = -1;

		vsi_pkt_total += vsi_pkt_count;

		vsi_pkt_count_prev_total += vsi_pkt_count_prev[pol->pfid[x]];
		vsi_pkt_count_prev[pol->pfid[x]] = vsi_pkt_count;
	}

	rdtsc_curr = rte_rdtsc_precise();
	rdtsc_diff = rdtsc_curr - rdtsc_prev[pol->pfid[x-1]];
	rdtsc_prev[pol->pfid[x-1]] = rdtsc_curr;

	diff = (vsi_pkt_total - vsi_pkt_count_prev_total) *
			((double)rte_get_tsc_hz() / rdtsc_diff);

	return diff;
}

static void
apply_traffic_profile(struct policy *pol)
{

	int count;
	uint64_t diff = 0;

	diff = get_pkt_diff(pol);

	RTE_LOG(INFO, CHANNEL_MONITOR, "Applying traffic profile\n");

	if (diff >= (pol->pkt.traffic_policy.max_max_packet_thresh)) {
		for (count = 0; count < pol->pkt.num_vcpu; count++) {
			if (pol->core_share[count].status != 1)
				power_manager_scale_core_max(
						pol->core_share[count].pcpu);
		}
	} else if (diff >= (pol->pkt.traffic_policy.avg_max_packet_thresh)) {
		for (count = 0; count < pol->pkt.num_vcpu; count++) {
			if (pol->core_share[count].status != 1)
				power_manager_scale_core_med(
						pol->core_share[count].pcpu);
		}
	} else if (diff < (pol->pkt.traffic_policy.avg_max_packet_thresh)) {
		for (count = 0; count < pol->pkt.num_vcpu; count++) {
			if (pol->core_share[count].status != 1)
				power_manager_scale_core_min(
						pol->core_share[count].pcpu);
		}
	}
}

static void
apply_time_profile(struct policy *pol)
{

	int count, x;
	struct timeval tv;
	struct tm *ptm;
	char time_string[40];

	/* Obtain the time of day, and convert it to a tm struct. */
	gettimeofday(&tv, NULL);
	ptm = localtime(&tv.tv_sec);
	/* Format the date and time, down to a single second. */
	strftime(time_string, sizeof(time_string), "%Y-%m-%d %H:%M:%S", ptm);

	for (x = 0; x < HOURS; x++) {

		if (ptm->tm_hour == pol->pkt.timer_policy.busy_hours[x]) {
			for (count = 0; count < pol->pkt.num_vcpu; count++) {
				if (pol->core_share[count].status != 1) {
					power_manager_scale_core_max(
						pol->core_share[count].pcpu);
				RTE_LOG(INFO, CHANNEL_MONITOR,
					"Scaling up core %d to max\n",
					pol->core_share[count].pcpu);
				}
			}
			break;
		} else if (ptm->tm_hour ==
				pol->pkt.timer_policy.quiet_hours[x]) {
			for (count = 0; count < pol->pkt.num_vcpu; count++) {
				if (pol->core_share[count].status != 1) {
					power_manager_scale_core_min(
						pol->core_share[count].pcpu);
				RTE_LOG(INFO, CHANNEL_MONITOR,
					"Scaling down core %d to min\n",
					pol->core_share[count].pcpu);
			}
		}
			break;
		} else if (ptm->tm_hour ==
			pol->pkt.timer_policy.hours_to_use_traffic_profile[x]) {
			apply_traffic_profile(pol);
			break;
		}
	}
}

static void
apply_workload_profile(struct policy *pol)
{

	int count;

	if (pol->pkt.workload == HIGH) {
		for (count = 0; count < pol->pkt.num_vcpu; count++) {
			if (pol->core_share[count].status != 1)
				power_manager_scale_core_max(
						pol->core_share[count].pcpu);
		}
	} else if (pol->pkt.workload == MEDIUM) {
		for (count = 0; count < pol->pkt.num_vcpu; count++) {
			if (pol->core_share[count].status != 1)
				power_manager_scale_core_med(
						pol->core_share[count].pcpu);
		}
	} else if (pol->pkt.workload == LOW) {
		for (count = 0; count < pol->pkt.num_vcpu; count++) {
			if (pol->core_share[count].status != 1)
				power_manager_scale_core_min(
						pol->core_share[count].pcpu);
		}
	}
}

static void
apply_policy(struct policy *pol)
{

	struct channel_packet *pkt = &pol->pkt;

	/*Check policy to use*/
	if (pkt->policy_to_use == TRAFFIC)
		apply_traffic_profile(pol);
	else if (pkt->policy_to_use == TIME)
		apply_time_profile(pol);
	else if (pkt->policy_to_use == WORKLOAD)
		apply_workload_profile(pol);
}


static int
process_request(struct channel_packet *pkt, struct channel_info *chan_info)
{
	uint64_t core_mask;

	if (chan_info == NULL)
		return -1;

	if (rte_atomic32_cmpset(&(chan_info->status), CHANNEL_MGR_CHANNEL_CONNECTED,
			CHANNEL_MGR_CHANNEL_PROCESSING) == 0)
		return -1;

	if (pkt->command == CPU_POWER) {
		core_mask = get_pcpus_mask(chan_info, pkt->resource_id);
		if (core_mask == 0) {
			RTE_LOG(ERR, CHANNEL_MONITOR, "Error get physical CPU mask for "
				"channel '%s' using vCPU(%u)\n", chan_info->channel_path,
				(unsigned)pkt->unit);
			return -1;
		}
		if (__builtin_popcountll(core_mask) == 1) {

			unsigned core_num = __builtin_ffsll(core_mask) - 1;

			switch (pkt->unit) {
			case(CPU_POWER_SCALE_MIN):
					power_manager_scale_core_min(core_num);
			break;
			case(CPU_POWER_SCALE_MAX):
					power_manager_scale_core_max(core_num);
			break;
			case(CPU_POWER_SCALE_DOWN):
					power_manager_scale_core_down(core_num);
			break;
			case(CPU_POWER_SCALE_UP):
					power_manager_scale_core_up(core_num);
			break;
			case(CPU_POWER_ENABLE_TURBO):
				power_manager_enable_turbo_core(core_num);
			break;
			case(CPU_POWER_DISABLE_TURBO):
				power_manager_disable_turbo_core(core_num);
			break;
			default:
				break;
			}
		} else {
			switch (pkt->unit) {
			case(CPU_POWER_SCALE_MIN):
					power_manager_scale_mask_min(core_mask);
			break;
			case(CPU_POWER_SCALE_MAX):
					power_manager_scale_mask_max(core_mask);
			break;
			case(CPU_POWER_SCALE_DOWN):
					power_manager_scale_mask_down(core_mask);
			break;
			case(CPU_POWER_SCALE_UP):
					power_manager_scale_mask_up(core_mask);
			break;
			case(CPU_POWER_ENABLE_TURBO):
				power_manager_enable_turbo_mask(core_mask);
			break;
			case(CPU_POWER_DISABLE_TURBO):
				power_manager_disable_turbo_mask(core_mask);
			break;
			default:
				break;
			}

		}
	}

	if (pkt->command == PKT_POLICY) {
		RTE_LOG(INFO, CHANNEL_MONITOR, "\nProcessing Policy request from Guest\n");
		update_policy(pkt);
		policy_is_set = 1;
	}

	/* Return is not checked as channel status may have been set to DISABLED
	 * from management thread
	 */
	rte_atomic32_cmpset(&(chan_info->status), CHANNEL_MGR_CHANNEL_PROCESSING,
			CHANNEL_MGR_CHANNEL_CONNECTED);
	return 0;

}

int
add_channel_to_monitor(struct channel_info **chan_info)
{
	struct channel_info *info = *chan_info;
	struct epoll_event event;

	event.events = EPOLLIN;
	event.data.ptr = info;
	if (epoll_ctl(global_event_fd, EPOLL_CTL_ADD, info->fd, &event) < 0) {
		RTE_LOG(ERR, CHANNEL_MONITOR, "Unable to add channel '%s' "
				"to epoll\n", info->channel_path);
		return -1;
	}
	return 0;
}

int
remove_channel_from_monitor(struct channel_info *chan_info)
{
	if (epoll_ctl(global_event_fd, EPOLL_CTL_DEL, chan_info->fd, NULL) < 0) {
		RTE_LOG(ERR, CHANNEL_MONITOR, "Unable to remove channel '%s' "
				"from epoll\n", chan_info->channel_path);
		return -1;
	}
	return 0;
}

int
channel_monitor_init(void)
{
	global_event_fd = epoll_create1(0);
	if (global_event_fd == 0) {
		RTE_LOG(ERR, CHANNEL_MONITOR, "Error creating epoll context with "
				"error %s\n", strerror(errno));
		return -1;
	}
	global_events_list = rte_malloc("epoll_events", sizeof(*global_events_list)
			* MAX_EVENTS, RTE_CACHE_LINE_SIZE);
	if (global_events_list == NULL) {
		RTE_LOG(ERR, CHANNEL_MONITOR, "Unable to rte_malloc for "
				"epoll events\n");
		return -1;
	}
	return 0;
}

void
run_channel_monitor(void)
{
	while (run_loop) {
		int n_events, i;

		n_events = epoll_wait(global_event_fd, global_events_list,
				MAX_EVENTS, 1);
		if (!run_loop)
			break;
		for (i = 0; i < n_events; i++) {
			struct channel_info *chan_info = (struct channel_info *)
					global_events_list[i].data.ptr;
			if ((global_events_list[i].events & EPOLLERR) ||
				(global_events_list[i].events & EPOLLHUP)) {
				RTE_LOG(DEBUG, CHANNEL_MONITOR, "Remote closed connection for "
						"channel '%s'\n",
						chan_info->channel_path);
				remove_channel(&chan_info);
				continue;
			}
			if (global_events_list[i].events & EPOLLIN) {

				int n_bytes, err = 0;
				struct channel_packet pkt;
				void *buffer = &pkt;
				int buffer_len = sizeof(pkt);

				while (buffer_len > 0) {
					n_bytes = read(chan_info->fd,
							buffer, buffer_len);
					if (n_bytes == buffer_len)
						break;
					if (n_bytes == -1) {
						err = errno;
						RTE_LOG(DEBUG, CHANNEL_MONITOR,
							"Received error on "
							"channel '%s' read: %s\n",
							chan_info->channel_path,
							strerror(err));
						remove_channel(&chan_info);
						break;
					}
					buffer = (char *)buffer + n_bytes;
					buffer_len -= n_bytes;
				}
				if (!err)
					process_request(&pkt, chan_info);
			}
		}
		rte_delay_us(time_period_s*1000000);
		if (policy_is_set) {
			int j;

			for (j = 0; j < MAX_VMS; j++) {
				if (policies[j].enabled == 1)
					apply_policy(&policies[j]);
			}
		}
	}
}