/* Intel(R) Ethernet Switch Host Interface Driver
 * Copyright(c) 2013 - 2016 Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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".
 *
 * Contact Information:
 * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 */

#include "fm10k_common.h"

/**
 *  fm10k_get_bus_info_generic - Generic set PCI bus info
 *  @hw: pointer to hardware structure
 *
 *  Gets the PCI bus info (speed, width, type) then calls helper function to
 *  store this data within the fm10k_hw structure.
 **/
s32 fm10k_get_bus_info_generic(struct fm10k_hw *hw)
{
        u16 link_cap, link_status, device_cap, device_control;

        /* Get the maximum link width and speed from PCIe config space */
        link_cap = fm10k_read_pci_cfg_word(hw, FM10K_PCIE_LINK_CAP);

        switch (link_cap & FM10K_PCIE_LINK_WIDTH) {
        case FM10K_PCIE_LINK_WIDTH_1:
                hw->bus_caps.width = fm10k_bus_width_pcie_x1;
                break;
        case FM10K_PCIE_LINK_WIDTH_2:
                hw->bus_caps.width = fm10k_bus_width_pcie_x2;
                break;
        case FM10K_PCIE_LINK_WIDTH_4:
                hw->bus_caps.width = fm10k_bus_width_pcie_x4;
                break;
        case FM10K_PCIE_LINK_WIDTH_8:
                hw->bus_caps.width = fm10k_bus_width_pcie_x8;
                break;
        default:
                hw->bus_caps.width = fm10k_bus_width_unknown;
                break;
        }

        switch (link_cap & FM10K_PCIE_LINK_SPEED) {
        case FM10K_PCIE_LINK_SPEED_2500:
                hw->bus_caps.speed = fm10k_bus_speed_2500;
                break;
        case FM10K_PCIE_LINK_SPEED_5000:
                hw->bus_caps.speed = fm10k_bus_speed_5000;
                break;
        case FM10K_PCIE_LINK_SPEED_8000:
                hw->bus_caps.speed = fm10k_bus_speed_8000;
                break;
        default:
                hw->bus_caps.speed = fm10k_bus_speed_unknown;
                break;
        }

        /* Get the PCIe maximum payload size for the PCIe function */
        device_cap = fm10k_read_pci_cfg_word(hw, FM10K_PCIE_DEV_CAP);

        switch (device_cap & FM10K_PCIE_DEV_CAP_PAYLOAD) {
        case FM10K_PCIE_DEV_CAP_PAYLOAD_128:
                hw->bus_caps.payload = fm10k_bus_payload_128;
                break;
        case FM10K_PCIE_DEV_CAP_PAYLOAD_256:
                hw->bus_caps.payload = fm10k_bus_payload_256;
                break;
        case FM10K_PCIE_DEV_CAP_PAYLOAD_512:
                hw->bus_caps.payload = fm10k_bus_payload_512;
                break;
        default:
                hw->bus_caps.payload = fm10k_bus_payload_unknown;
                break;
        }

        /* Get the negotiated link width and speed from PCIe config space */
        link_status = fm10k_read_pci_cfg_word(hw, FM10K_PCIE_LINK_STATUS);

        switch (link_status & FM10K_PCIE_LINK_WIDTH) {
        case FM10K_PCIE_LINK_WIDTH_1:
                hw->bus.width = fm10k_bus_width_pcie_x1;
                break;
        case FM10K_PCIE_LINK_WIDTH_2:
                hw->bus.width = fm10k_bus_width_pcie_x2;
                break;
        case FM10K_PCIE_LINK_WIDTH_4:
                hw->bus.width = fm10k_bus_width_pcie_x4;
                break;
        case FM10K_PCIE_LINK_WIDTH_8:
                hw->bus.width = fm10k_bus_width_pcie_x8;
                break;
        default:
                hw->bus.width = fm10k_bus_width_unknown;
                break;
        }

        switch (link_status & FM10K_PCIE_LINK_SPEED) {
        case FM10K_PCIE_LINK_SPEED_2500:
                hw->bus.speed = fm10k_bus_speed_2500;
                break;
        case FM10K_PCIE_LINK_SPEED_5000:
                hw->bus.speed = fm10k_bus_speed_5000;
                break;
        case FM10K_PCIE_LINK_SPEED_8000:
                hw->bus.speed = fm10k_bus_speed_8000;
                break;
        default:
                hw->bus.speed = fm10k_bus_speed_unknown;
                break;
        }

        /* Get the negotiated PCIe maximum payload size for the PCIe function */
        device_control = fm10k_read_pci_cfg_word(hw, FM10K_PCIE_DEV_CTRL);

        switch (device_control & FM10K_PCIE_DEV_CTRL_PAYLOAD) {
        case FM10K_PCIE_DEV_CTRL_PAYLOAD_128:
                hw->bus.payload = fm10k_bus_payload_128;
                break;
        case FM10K_PCIE_DEV_CTRL_PAYLOAD_256:
                hw->bus.payload = fm10k_bus_payload_256;
                break;
        case FM10K_PCIE_DEV_CTRL_PAYLOAD_512:
                hw->bus.payload = fm10k_bus_payload_512;
                break;
        default:
                hw->bus.payload = fm10k_bus_payload_unknown;
                break;
        }

        return 0;
}

static u16 fm10k_get_pcie_msix_count_generic(struct fm10k_hw *hw)
{
        u16 msix_count;

        /* read in value from MSI-X capability register */
        msix_count = fm10k_read_pci_cfg_word(hw, FM10K_PCI_MSIX_MSG_CTRL);
        msix_count &= FM10K_PCI_MSIX_MSG_CTRL_TBL_SZ_MASK;

        /* MSI-X count is zero-based in HW */
        msix_count++;

        if (msix_count > FM10K_MAX_MSIX_VECTORS)
                msix_count = FM10K_MAX_MSIX_VECTORS;

        return msix_count;
}

/**
 *  fm10k_get_invariants_generic - Inits constant values
 *  @hw: pointer to the hardware structure
 *
 *  Initialize the common invariants for the device.
 **/
s32 fm10k_get_invariants_generic(struct fm10k_hw *hw)
{
        struct fm10k_mac_info *mac = &hw->mac;

        /* initialize GLORT state to avoid any false hits */
        mac->dglort_map = FM10K_DGLORTMAP_NONE;

        /* record maximum number of MSI-X vectors */
        mac->max_msix_vectors = fm10k_get_pcie_msix_count_generic(hw);

        return 0;
}

/**
 *  fm10k_start_hw_generic - Prepare hardware for Tx/Rx
 *  @hw: pointer to hardware structure
 *
 *  This function sets the Tx ready flag to indicate that the Tx path has
 *  been initialized.
 **/
s32 fm10k_start_hw_generic(struct fm10k_hw *hw)
{
        /* set flag indicating we are beginning Tx */
        hw->mac.tx_ready = true;

        return 0;
}

/**
 *  fm10k_disable_queues_generic - Stop Tx/Rx queues
 *  @hw: pointer to hardware structure
 *  @q_cnt: number of queues to be disabled
 *
 **/
s32 fm10k_disable_queues_generic(struct fm10k_hw *hw, u16 q_cnt)
{
        u32 reg;
        u16 i, time;

        /* clear tx_ready to prevent any false hits for reset */
        hw->mac.tx_ready = false;

        if (FM10K_REMOVED(hw->hw_addr))
                return 0;

        /* clear the enable bit for all rings */
        for (i = 0; i < q_cnt; i++) {
                reg = fm10k_read_reg(hw, FM10K_TXDCTL(i));
                fm10k_write_reg(hw, FM10K_TXDCTL(i),
                                reg & ~FM10K_TXDCTL_ENABLE);
                reg = fm10k_read_reg(hw, FM10K_RXQCTL(i));
                fm10k_write_reg(hw, FM10K_RXQCTL(i),
                                reg & ~FM10K_RXQCTL_ENABLE);
        }

        fm10k_write_flush(hw);
        udelay(1);

        /* loop through all queues to verify that they are all disabled */
        for (i = 0, time = FM10K_QUEUE_DISABLE_TIMEOUT; time;) {
                /* if we are at end of rings all rings are disabled */
                if (i == q_cnt)
                        return 0;

                /* if queue enables cleared, then move to next ring pair */
                reg = fm10k_read_reg(hw, FM10K_TXDCTL(i));
                if (!~reg || !(reg & FM10K_TXDCTL_ENABLE)) {
                        reg = fm10k_read_reg(hw, FM10K_RXQCTL(i));
                        if (!~reg || !(reg & FM10K_RXQCTL_ENABLE)) {
                                i++;
                                continue;
                        }
                }

                /* decrement time and wait 1 usec */
                time--;
                if (time)
                        udelay(1);
        }

        return FM10K_ERR_REQUESTS_PENDING;
}

/**
 *  fm10k_stop_hw_generic - Stop Tx/Rx units
 *  @hw: pointer to hardware structure
 *
 **/
s32 fm10k_stop_hw_generic(struct fm10k_hw *hw)
{
        return fm10k_disable_queues_generic(hw, hw->mac.max_queues);
}

/**
 *  fm10k_read_hw_stats_32b - Reads value of 32-bit registers
 *  @hw: pointer to the hardware structure
 *  @addr: address of register containing a 32-bit value
 *
 *  Function reads the content of the register and returns the delta
 *  between the base and the current value.
 *  **/
u32 fm10k_read_hw_stats_32b(struct fm10k_hw *hw, u32 addr,
                            struct fm10k_hw_stat *stat)
{
        u32 delta = fm10k_read_reg(hw, addr) - stat->base_l;

        if (FM10K_REMOVED(hw->hw_addr))
                stat->base_h = 0;

        return delta;
}

/**
 *  fm10k_read_hw_stats_48b - Reads value of 48-bit registers
 *  @hw: pointer to the hardware structure
 *  @addr: address of register containing the lower 32-bit value
 *
 *  Function reads the content of 2 registers, combined to represent a 48-bit
 *  statistical value. Extra processing is required to handle overflowing.
 *  Finally, a delta value is returned representing the difference between the
 *  values stored in registers and values stored in the statistic counters.
 *  **/
static u64 fm10k_read_hw_stats_48b(struct fm10k_hw *hw, u32 addr,
                                   struct fm10k_hw_stat *stat)
{
        u32 count_l;
        u32 count_h;
        u32 count_tmp;
        u64 delta;

        count_h = fm10k_read_reg(hw, addr + 1);

        /* Check for overflow */
        do {
                count_tmp = count_h;
                count_l = fm10k_read_reg(hw, addr);
                count_h = fm10k_read_reg(hw, addr + 1);
        } while (count_h != count_tmp);

        delta = ((u64)(count_h - stat->base_h) << 32) + count_l;
        delta -= stat->base_l;

        return delta & FM10K_48_BIT_MASK;
}

/**
 *  fm10k_update_hw_base_48b - Updates 48-bit statistic base value
 *  @stat: pointer to the hardware statistic structure
 *  @delta: value to be updated into the hardware statistic structure
 *
 *  Function receives a value and determines if an update is required based on
 *  a delta calculation. Only the base value will be updated.
 **/
static void fm10k_update_hw_base_48b(struct fm10k_hw_stat *stat, u64 delta)
{
        if (!delta)
                return;

        /* update lower 32 bits */
        delta += stat->base_l;
        stat->base_l = (u32)delta;

        /* update upper 32 bits */
        stat->base_h += (u32)(delta >> 32);
}

/**
 *  fm10k_update_hw_stats_tx_q - Updates TX queue statistics counters
 *  @hw: pointer to the hardware structure
 *  @q: pointer to the ring of hardware statistics queue
 *  @idx: index pointing to the start of the ring iteration
 *
 *  Function updates the TX queue statistics counters that are related to the
 *  hardware.
 **/
static void fm10k_update_hw_stats_tx_q(struct fm10k_hw *hw,
                                       struct fm10k_hw_stats_q *q,
                                       u32 idx)
{
        u32 id_tx, id_tx_prev, tx_packets;
        u64 tx_bytes = 0;

        /* Retrieve TX Owner Data */
        id_tx = fm10k_read_reg(hw, FM10K_TXQCTL(idx));

        /* Process TX Ring */
        do {
                tx_packets = fm10k_read_hw_stats_32b(hw, FM10K_QPTC(idx),
                                                     &q->tx_packets);

                if (tx_packets)
                        tx_bytes = fm10k_read_hw_stats_48b(hw,
                                                           FM10K_QBTC_L(idx),
                                                           &q->tx_bytes);

                /* Re-Check Owner Data */
                id_tx_prev = id_tx;
                id_tx = fm10k_read_reg(hw, FM10K_TXQCTL(idx));
        } while ((id_tx ^ id_tx_prev) & FM10K_TXQCTL_ID_MASK);

        /* drop non-ID bits and set VALID ID bit */
        id_tx &= FM10K_TXQCTL_ID_MASK;
        id_tx |= FM10K_STAT_VALID;

        /* update packet counts */
        if (q->tx_stats_idx == id_tx) {
                q->tx_packets.count += tx_packets;
                q->tx_bytes.count += tx_bytes;
        }

        /* update bases and record ID */
        fm10k_update_hw_base_32b(&q->tx_packets, tx_packets);
        fm10k_update_hw_base_48b(&q->tx_bytes, tx_bytes);

        q->tx_stats_idx = id_tx;
}

/**
 *  fm10k_update_hw_stats_rx_q - Updates RX queue statistics counters
 *  @hw: pointer to the hardware structure
 *  @q: pointer to the ring of hardware statistics queue
 *  @idx: index pointing to the start of the ring iteration
 *
 *  Function updates the RX queue statistics counters that are related to the
 *  hardware.
 **/
static void fm10k_update_hw_stats_rx_q(struct fm10k_hw *hw,
                                       struct fm10k_hw_stats_q *q,
                                       u32 idx)
{
        u32 id_rx, id_rx_prev, rx_packets, rx_drops;
        u64 rx_bytes = 0;

        /* Retrieve RX Owner Data */
        id_rx = fm10k_read_reg(hw, FM10K_RXQCTL(idx));

        /* Process RX Ring */
        do {
                rx_drops = fm10k_read_hw_stats_32b(hw, FM10K_QPRDC(idx),
                                                   &q->rx_drops);

                rx_packets = fm10k_read_hw_stats_32b(hw, FM10K_QPRC(idx),
                                                     &q->rx_packets);

                if (rx_packets)
                        rx_bytes = fm10k_read_hw_stats_48b(hw,
                                                           FM10K_QBRC_L(idx),
                                                           &q->rx_bytes);

                /* Re-Check Owner Data */
                id_rx_prev = id_rx;
                id_rx = fm10k_read_reg(hw, FM10K_RXQCTL(idx));
        } while ((id_rx ^ id_rx_prev) & FM10K_RXQCTL_ID_MASK);

        /* drop non-ID bits and set VALID ID bit */
        id_rx &= FM10K_RXQCTL_ID_MASK;
        id_rx |= FM10K_STAT_VALID;

        /* update packet counts */
        if (q->rx_stats_idx == id_rx) {
                q->rx_drops.count += rx_drops;
                q->rx_packets.count += rx_packets;
                q->rx_bytes.count += rx_bytes;
        }

        /* update bases and record ID */
        fm10k_update_hw_base_32b(&q->rx_drops, rx_drops);
        fm10k_update_hw_base_32b(&q->rx_packets, rx_packets);
        fm10k_update_hw_base_48b(&q->rx_bytes, rx_bytes);

        q->rx_stats_idx = id_rx;
}

/**
 *  fm10k_update_hw_stats_q - Updates queue statistics counters
 *  @hw: pointer to the hardware structure
 *  @q: pointer to the ring of hardware statistics queue
 *  @idx: index pointing to the start of the ring iteration
 *  @count: number of queues to iterate over
 *
 *  Function updates the queue statistics counters that are related to the
 *  hardware.
 **/
void fm10k_update_hw_stats_q(struct fm10k_hw *hw, struct fm10k_hw_stats_q *q,
                             u32 idx, u32 count)
{
        u32 i;

        for (i = 0; i < count; i++, idx++, q++) {
                fm10k_update_hw_stats_tx_q(hw, q, idx);
                fm10k_update_hw_stats_rx_q(hw, q, idx);
        }
}

/**
 *  fm10k_unbind_hw_stats_q - Unbind the queue counters from their queues
 *  @hw: pointer to the hardware structure
 *  @q: pointer to the ring of hardware statistics queue
 *  @idx: index pointing to the start of the ring iteration
 *  @count: number of queues to iterate over
 *
 *  Function invalidates the index values for the queues so any updates that
 *  may have happened are ignored and the base for the queue stats is reset.
 **/
void fm10k_unbind_hw_stats_q(struct fm10k_hw_stats_q *q, u32 idx, u32 count)
{
        u32 i;

        for (i = 0; i < count; i++, idx++, q++) {
                q->rx_stats_idx = 0;
                q->tx_stats_idx = 0;
        }
}

/**
 *  fm10k_get_host_state_generic - Returns the state of the host
 *  @hw: pointer to hardware structure
 *  @host_ready: pointer to boolean value that will record host state
 *
 *  This function will check the health of the mailbox and Tx queue 0
 *  in order to determine if we should report that the link is up or not.
 **/
s32 fm10k_get_host_state_generic(struct fm10k_hw *hw, bool *host_ready)
{
        struct fm10k_mbx_info *mbx = &hw->mbx;
        struct fm10k_mac_info *mac = &hw->mac;
        s32 ret_val = 0;
        u32 txdctl = fm10k_read_reg(hw, FM10K_TXDCTL(0));

        /* process upstream mailbox in case interrupts were disabled */
        mbx->ops.process(hw, mbx);

        /* If Tx is no longer enabled link should come down */
        if (!(~txdctl) || !(txdctl & FM10K_TXDCTL_ENABLE))
                mac->get_host_state = true;

        /* exit if not checking for link, or link cannot be changed */
        if (!mac->get_host_state || !(~txdctl))
                goto out;

        /* if we somehow dropped the Tx enable we should reset */
        if (mac->tx_ready && !(txdctl & FM10K_TXDCTL_ENABLE)) {
                ret_val = FM10K_ERR_RESET_REQUESTED;
                goto out;
        }

        /* if Mailbox timed out we should request reset */
        if (!mbx->timeout) {
                ret_val = FM10K_ERR_RESET_REQUESTED;
                goto out;
        }

        /* verify Mailbox is still valid */
        if (!mbx->ops.tx_ready(mbx, FM10K_VFMBX_MSG_MTU))
                goto out;

        /* interface cannot receive traffic without logical ports */
        if (mac->dglort_map == FM10K_DGLORTMAP_NONE) {
                if (mac->ops.request_lport_map)
                        ret_val = mac->ops.request_lport_map(hw);

                goto out;
        }

        /* if we passed all the tests above then the switch is ready and we no
         * longer need to check for link
         */
        mac->get_host_state = false;

out:
        *host_ready = !mac->get_host_state;
        return ret_val;
}