/*
 * Copyright 2015 Amazon.com, Inc. or its affiliates.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * BSD license below:
 *
 *     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.
 *
 * 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 AUTHORS OR COPYRIGHT HOLDERS
 * 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.
 */

#ifndef ENA_H
#define ENA_H

#include <linux/bitops.h>
#include <linux/dim.h>
#include <linux/etherdevice.h>
#include <linux/if_vlan.h>
#include <linux/inetdevice.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>

#include "ena_com.h"
#include "ena_eth_com.h"

#define DRV_MODULE_GEN_MAJOR    2
#define DRV_MODULE_GEN_MINOR    1
#define DRV_MODULE_GEN_SUBMINOR 0

#define DRV_MODULE_NAME         "ena"

#define DEVICE_NAME     "Elastic Network Adapter (ENA)"

/* 1 for AENQ + ADMIN */
#define ENA_ADMIN_MSIX_VEC              1
#define ENA_MAX_MSIX_VEC(io_queues)     (ENA_ADMIN_MSIX_VEC + (io_queues))

/* The ENA buffer length fields is 16 bit long. So when PAGE_SIZE == 64kB the
 * driver passes 0.
 * Since the max packet size the ENA handles is ~9kB limit the buffer length to
 * 16kB.
 */
#if PAGE_SIZE > SZ_16K
#define ENA_PAGE_SIZE (_AC(SZ_16K, UL))
#else
#define ENA_PAGE_SIZE PAGE_SIZE
#endif

#define ENA_MIN_MSIX_VEC                2

#define ENA_REG_BAR                     0
#define ENA_MEM_BAR                     2
#define ENA_BAR_MASK (BIT(ENA_REG_BAR) | BIT(ENA_MEM_BAR))

#define ENA_DEFAULT_RING_SIZE   (1024)
#define ENA_MIN_RING_SIZE       (256)

#define ENA_MIN_NUM_IO_QUEUES   (1)

#define ENA_TX_WAKEUP_THRESH            (MAX_SKB_FRAGS + 2)
#define ENA_DEFAULT_RX_COPYBREAK        (256 - NET_IP_ALIGN)

/* limit the buffer size to 600 bytes to handle MTU changes from very
 * small to very large, in which case the number of buffers per packet
 * could exceed ENA_PKT_MAX_BUFS
 */
#define ENA_DEFAULT_MIN_RX_BUFF_ALLOC_SIZE 600

#define ENA_MIN_MTU             128

#define ENA_NAME_MAX_LEN        20
#define ENA_IRQNAME_SIZE        40

#define ENA_PKT_MAX_BUFS        19

#define ENA_RX_RSS_TABLE_LOG_SIZE  7
#define ENA_RX_RSS_TABLE_SIZE   (1 << ENA_RX_RSS_TABLE_LOG_SIZE)

/* The number of tx packet completions that will be handled each NAPI poll
 * cycle is ring_size / ENA_TX_POLL_BUDGET_DIVIDER.
 */
#define ENA_TX_POLL_BUDGET_DIVIDER      4

/* Refill Rx queue when number of required descriptors is above
 * QUEUE_SIZE / ENA_RX_REFILL_THRESH_DIVIDER or ENA_RX_REFILL_THRESH_PACKET
 */
#define ENA_RX_REFILL_THRESH_DIVIDER    8
#define ENA_RX_REFILL_THRESH_PACKET     256

/* Number of queues to check for missing queues per timer service */
#define ENA_MONITORED_TX_QUEUES 4
/* Max timeout packets before device reset */
#define MAX_NUM_OF_TIMEOUTED_PACKETS 128

#define ENA_TX_RING_IDX_NEXT(idx, ring_size) (((idx) + 1) & ((ring_size) - 1))

#define ENA_RX_RING_IDX_NEXT(idx, ring_size) (((idx) + 1) & ((ring_size) - 1))
#define ENA_RX_RING_IDX_ADD(idx, n, ring_size) \
        (((idx) + (n)) & ((ring_size) - 1))

#define ENA_IO_TXQ_IDX(q)       (2 * (q))
#define ENA_IO_RXQ_IDX(q)       (2 * (q) + 1)
#define ENA_IO_TXQ_IDX_TO_COMBINED_IDX(q)       ((q) / 2)
#define ENA_IO_RXQ_IDX_TO_COMBINED_IDX(q)       (((q) - 1) / 2)

#define ENA_MGMNT_IRQ_IDX               0
#define ENA_IO_IRQ_FIRST_IDX            1
#define ENA_IO_IRQ_IDX(q)               (ENA_IO_IRQ_FIRST_IDX + (q))

#define ENA_ADMIN_POLL_DELAY_US 100

/* ENA device should send keep alive msg every 1 sec.
 * We wait for 6 sec just to be on the safe side.
 */
#define ENA_DEVICE_KALIVE_TIMEOUT       (6 * HZ)
#define ENA_MAX_NO_INTERRUPT_ITERATIONS 3

#define ENA_MMIO_DISABLE_REG_READ       BIT(0)

/* The max MTU size is configured to be the ethernet frame size without
 * the overhead of the ethernet header, which can have a VLAN header, and
 * a frame check sequence (FCS).
 * The buffer size we share with the device is defined to be ENA_PAGE_SIZE
 */

#define ENA_XDP_MAX_MTU (ENA_PAGE_SIZE - ETH_HLEN - ETH_FCS_LEN -       \
                         VLAN_HLEN - XDP_PACKET_HEADROOM -              \
                         SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))

#define ENA_IS_XDP_INDEX(adapter, index) (((index) >= (adapter)->xdp_first_ring) && \
        ((index) < (adapter)->xdp_first_ring + (adapter)->xdp_num_queues))

struct ena_irq {
        irq_handler_t handler;
        void *data;
        int cpu;
        u32 vector;
        cpumask_t affinity_hint_mask;
        char name[ENA_IRQNAME_SIZE];
};

struct ena_napi {
        struct napi_struct napi ____cacheline_aligned;
        struct ena_ring *tx_ring;
        struct ena_ring *rx_ring;
        struct ena_ring *xdp_ring;
        bool first_interrupt;
        bool interrupts_masked;
        u32 qid;
        struct dim dim;
};

struct ena_calc_queue_size_ctx {
        struct ena_com_dev_get_features_ctx *get_feat_ctx;
        struct ena_com_dev *ena_dev;
        struct pci_dev *pdev;
        u32 tx_queue_size;
        u32 rx_queue_size;
        u32 max_tx_queue_size;
        u32 max_rx_queue_size;
        u16 max_tx_sgl_size;
        u16 max_rx_sgl_size;
};

struct ena_tx_buffer {
        struct sk_buff *skb;
        /* num of ena desc for this specific skb
         * (includes data desc and metadata desc)
         */
        u32 tx_descs;
        /* num of buffers used by this skb */
        u32 num_of_bufs;

        /* XDP buffer structure which is used for sending packets in
         * the xdp queues
         */
        struct xdp_frame *xdpf;
        /* The rx page for the rx buffer that was received in rx and
         * re transmitted on xdp tx queues as a result of XDP_TX action.
         * We need to free the page once we finished cleaning the buffer in
         * clean_xdp_irq()
         */
        struct page *xdp_rx_page;

        /* Indicate if bufs[0] map the linear data of the skb. */
        u8 map_linear_data;

        /* Used for detect missing tx packets to limit the number of prints */
        u32 print_once;
        /* Save the last jiffies to detect missing tx packets
         *
         * sets to non zero value on ena_start_xmit and set to zero on
         * napi and timer_Service_routine.
         *
         * while this value is not protected by lock,
         * a given packet is not expected to be handled by ena_start_xmit
         * and by napi/timer_service at the same time.
         */
        unsigned long last_jiffies;
        struct ena_com_buf bufs[ENA_PKT_MAX_BUFS];
} ____cacheline_aligned;

struct ena_rx_buffer {
        struct sk_buff *skb;
        struct page *page;
        u32 page_offset;
        struct ena_com_buf ena_buf;
} ____cacheline_aligned;

struct ena_stats_tx {
        u64 cnt;
        u64 bytes;
        u64 queue_stop;
        u64 prepare_ctx_err;
        u64 queue_wakeup;
        u64 dma_mapping_err;
        u64 linearize;
        u64 linearize_failed;
        u64 napi_comp;
        u64 tx_poll;
        u64 doorbells;
        u64 bad_req_id;
        u64 llq_buffer_copy;
        u64 missed_tx;
        u64 unmask_interrupt;
};

struct ena_stats_rx {
        u64 cnt;
        u64 bytes;
        u64 rx_copybreak_pkt;
        u64 csum_good;
        u64 refil_partial;
        u64 bad_csum;
        u64 page_alloc_fail;
        u64 skb_alloc_fail;
        u64 dma_mapping_err;
        u64 bad_desc_num;
        u64 bad_req_id;
        u64 empty_rx_ring;
        u64 csum_unchecked;
};

struct ena_ring {
        /* Holds the empty requests for TX/RX
         * out of order completions
         */
        u16 *free_ids;

        union {
                struct ena_tx_buffer *tx_buffer_info;
                struct ena_rx_buffer *rx_buffer_info;
        };

        /* cache ptr to avoid using the adapter */
        struct device *dev;
        struct pci_dev *pdev;
        struct napi_struct *napi;
        struct net_device *netdev;
        struct ena_com_dev *ena_dev;
        struct ena_adapter *adapter;
        struct ena_com_io_cq *ena_com_io_cq;
        struct ena_com_io_sq *ena_com_io_sq;
        struct bpf_prog *xdp_bpf_prog;
        struct xdp_rxq_info xdp_rxq;

        u16 next_to_use;
        u16 next_to_clean;
        u16 rx_copybreak;
        u16 rx_headroom;
        u16 qid;
        u16 mtu;
        u16 sgl_size;

        /* The maximum header length the device can handle */
        u8 tx_max_header_size;

        bool first_interrupt;
        bool disable_meta_caching;
        u16 no_interrupt_event_cnt;

        /* cpu for TPH */
        int cpu;
         /* number of tx/rx_buffer_info's entries */
        int ring_size;

        enum ena_admin_placement_policy_type tx_mem_queue_type;

        struct ena_com_rx_buf_info ena_bufs[ENA_PKT_MAX_BUFS];
        u32  smoothed_interval;
        u32  per_napi_packets;
        u16 non_empty_napi_events;
        struct u64_stats_sync syncp;
        union {
                struct ena_stats_tx tx_stats;
                struct ena_stats_rx rx_stats;
        };

        u8 *push_buf_intermediate_buf;
        int empty_rx_queue;
} ____cacheline_aligned;

struct ena_stats_dev {
        u64 tx_timeout;
        u64 suspend;
        u64 resume;
        u64 wd_expired;
        u64 interface_up;
        u64 interface_down;
        u64 admin_q_pause;
        u64 rx_drops;
        u64 tx_drops;
};

enum ena_flags_t {
        ENA_FLAG_DEVICE_RUNNING,
        ENA_FLAG_DEV_UP,
        ENA_FLAG_LINK_UP,
        ENA_FLAG_MSIX_ENABLED,
        ENA_FLAG_TRIGGER_RESET,
        ENA_FLAG_ONGOING_RESET
};

/* adapter specific private data structure */
struct ena_adapter {
        struct ena_com_dev *ena_dev;
        /* OS defined structs */
        struct net_device *netdev;
        struct pci_dev *pdev;

        /* rx packets that shorter that this len will be copied to the skb
         * header
         */
        u32 rx_copybreak;
        u32 max_mtu;

        u32 num_io_queues;
        u32 max_num_io_queues;

        int msix_vecs;

        u32 missing_tx_completion_threshold;

        u32 requested_tx_ring_size;
        u32 requested_rx_ring_size;

        u32 max_tx_ring_size;
        u32 max_rx_ring_size;

        u32 msg_enable;

        u16 max_tx_sgl_size;
        u16 max_rx_sgl_size;

        u8 mac_addr[ETH_ALEN];

        unsigned long keep_alive_timeout;
        unsigned long missing_tx_completion_to;

        char name[ENA_NAME_MAX_LEN];

        unsigned long flags;
        /* TX */
        struct ena_ring tx_ring[ENA_MAX_NUM_IO_QUEUES]
                ____cacheline_aligned_in_smp;

        /* RX */
        struct ena_ring rx_ring[ENA_MAX_NUM_IO_QUEUES]
                ____cacheline_aligned_in_smp;

        struct ena_napi ena_napi[ENA_MAX_NUM_IO_QUEUES];

        struct ena_irq irq_tbl[ENA_MAX_MSIX_VEC(ENA_MAX_NUM_IO_QUEUES)];

        /* timer service */
        struct work_struct reset_task;
        struct timer_list timer_service;

        bool wd_state;
        bool dev_up_before_reset;
        bool disable_meta_caching;
        unsigned long last_keep_alive_jiffies;

        struct u64_stats_sync syncp;
        struct ena_stats_dev dev_stats;

        /* last queue index that was checked for uncompleted tx packets */
        u32 last_monitored_tx_qid;

        enum ena_regs_reset_reason_types reset_reason;

        struct bpf_prog *xdp_bpf_prog;
        u32 xdp_first_ring;
        u32 xdp_num_queues;
};

void ena_set_ethtool_ops(struct net_device *netdev);

void ena_dump_stats_to_dmesg(struct ena_adapter *adapter);

void ena_dump_stats_to_buf(struct ena_adapter *adapter, u8 *buf);

int ena_update_queue_sizes(struct ena_adapter *adapter,
                           u32 new_tx_size,
                           u32 new_rx_size);

int ena_update_queue_count(struct ena_adapter *adapter, u32 new_channel_count);

int ena_get_sset_count(struct net_device *netdev, int sset);

enum ena_xdp_errors_t {
        ENA_XDP_ALLOWED = 0,
        ENA_XDP_CURRENT_MTU_TOO_LARGE,
        ENA_XDP_NO_ENOUGH_QUEUES,
};

static inline bool ena_xdp_queues_present(struct ena_adapter *adapter)
{
        return adapter->xdp_first_ring != 0;
}

static inline bool ena_xdp_present(struct ena_adapter *adapter)
{
        return !!adapter->xdp_bpf_prog;
}

static inline bool ena_xdp_present_ring(struct ena_ring *ring)
{
        return !!ring->xdp_bpf_prog;
}

static inline int ena_xdp_legal_queue_count(struct ena_adapter *adapter,
                                            u32 queues)
{
        return 2 * queues <= adapter->max_num_io_queues;
}

static inline enum ena_xdp_errors_t ena_xdp_allowed(struct ena_adapter *adapter)
{
        enum ena_xdp_errors_t rc = ENA_XDP_ALLOWED;

        if (adapter->netdev->mtu > ENA_XDP_MAX_MTU)
                rc = ENA_XDP_CURRENT_MTU_TOO_LARGE;
        else if (!ena_xdp_legal_queue_count(adapter, adapter->num_io_queues))
                rc = ENA_XDP_NO_ENOUGH_QUEUES;

        return rc;
}

#endif /* !(ENA_H) */