/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
/*
 * Copyright(c) 2023 - Cornelis Networks, Inc.
 * Copyright(c) 2015 - 2018 Intel Corporation.
 */
#ifndef _HFI1_USER_SDMA_H
#define _HFI1_USER_SDMA_H

#include <linux/device.h>
#include <linux/wait.h>

#include "common.h"
#include "iowait.h"
#include "user_exp_rcv.h"
#include "mmu_rb.h"
#include "pinning.h"
#include "sdma.h"

/* The maximum number of Data io vectors per message/request */
#define MAX_VECTORS_PER_REQ 8
/*
 * Maximum number of packet to send from each message/request
 * before moving to the next one.
 */
#define MAX_PKTS_PER_QUEUE 16

#define num_pages(x) (1 + ((((x) - 1) & PAGE_MASK) >> PAGE_SHIFT))

#define req_opcode(x) \
        (((x) >> HFI1_SDMA_REQ_OPCODE_SHIFT) & HFI1_SDMA_REQ_OPCODE_MASK)
#define req_version(x) \
        (((x) >> HFI1_SDMA_REQ_VERSION_SHIFT) & HFI1_SDMA_REQ_OPCODE_MASK)
#define req_iovcnt(x) \
        (((x) >> HFI1_SDMA_REQ_IOVCNT_SHIFT) & HFI1_SDMA_REQ_IOVCNT_MASK)

/* Number of BTH.PSN bits used for sequence number in expected rcvs */
#define BTH_SEQ_MASK 0x7ffull

#define AHG_KDETH_INTR_SHIFT 12
#define AHG_KDETH_SH_SHIFT   13
#define AHG_KDETH_ARRAY_SIZE  9

#define PBC2LRH(x) ((((x) & 0xfff) << 2) - 4)
#define LRH2PBC(x) ((((x) >> 2) + 1) & 0xfff)

/**
 * Build an SDMA AHG header update descriptor and save it to an array.
 * @arr        - Array to save the descriptor to.
 * @idx        - Index of the array at which the descriptor will be saved.
 * @array_size - Size of the array arr.
 * @dw         - Update index into the header in DWs.
 * @bit        - Start bit.
 * @width      - Field width.
 * @value      - 16 bits of immediate data to write into the field.
 * Returns -ERANGE if idx is invalid. If successful, returns the next index
 * (idx + 1) of the array to be used for the next descriptor.
 */
static inline int ahg_header_set(u32 *arr, int idx, size_t array_size,
                                 u8 dw, u8 bit, u8 width, u16 value)
{
        if ((size_t)idx >= array_size)
                return -ERANGE;
        arr[idx++] = sdma_build_ahg_descriptor(value, dw, bit, width);
        return idx;
}

/* Tx request flag bits */
#define TXREQ_FLAGS_REQ_ACK   BIT(0)      /* Set the ACK bit in the header */
#define TXREQ_FLAGS_REQ_DISABLE_SH BIT(1) /* Disable header suppression */

enum pkt_q_sdma_state {
        SDMA_PKT_Q_ACTIVE,
        SDMA_PKT_Q_DEFERRED,
};

#define SDMA_IOWAIT_TIMEOUT 1000 /* in milliseconds */

#define SDMA_DBG(req, fmt, ...)                              \
        hfi1_cdbg(SDMA, "[%u:%u:%u:%u] " fmt, (req)->pq->dd->unit, \
                 (req)->pq->ctxt, (req)->pq->subctxt, (req)->info.comp_idx, \
                 ##__VA_ARGS__)

struct hfi1_user_sdma_pkt_q {
        u16 ctxt;
        u16 subctxt;
        u16 n_max_reqs;
        atomic_t n_reqs;
        u16 reqidx;
        struct hfi1_devdata *dd;
        struct kmem_cache *txreq_cache;
        struct user_sdma_request *reqs;
        unsigned long *req_in_use;
        struct iowait busy;
        enum pkt_q_sdma_state state;
        wait_queue_head_t wait;
        unsigned long unpinned;
        struct mmu_rb_handler *handler;
        atomic_t n_locked;
};

struct hfi1_user_sdma_comp_q {
        u16 nentries;
        struct hfi1_sdma_comp_entry *comps;
};

struct user_sdma_iovec {
        struct list_head list;
        struct iovec iov;
        /*
         * offset into the virtual address space of the vector at
         * which we last left off.
         */
        u64 offset;
};

/* evict operation argument */
struct evict_data {
        u32 cleared;    /* count evicted so far */
        u32 target;     /* target count to evict */
};

struct user_sdma_request {
        /* This is the original header from user space */
        struct hfi1_pkt_header hdr;

        /* Read mostly fields */
        struct hfi1_user_sdma_pkt_q *pq ____cacheline_aligned_in_smp;
        struct hfi1_user_sdma_comp_q *cq;
        /*
         * Pointer to the SDMA engine for this request.
         * Since different request could be on different VLs,
         * each request will need it's own engine pointer.
         */
        struct sdma_engine *sde;
        struct sdma_req_info info;
        /* TID array values copied from the tid_iov vector */
        u32 *tids;
        /* total length of the data in the request */
        u32 data_len;
        /* number of elements copied to the tids array */
        u16 n_tids;
        /*
         * We copy the iovs for this request (based on
         * info.iovcnt). These are only the data vectors
         */
        u8 data_iovs;
        s8 ahg_idx;

        /* Writeable fields shared with interrupt */
        u16 seqcomp ____cacheline_aligned_in_smp;
        u16 seqsubmitted;

        /* Send side fields */
        struct list_head txps ____cacheline_aligned_in_smp;
        u16 seqnum;
        /*
         * KDETH.OFFSET (TID) field
         * The offset can cover multiple packets, depending on the
         * size of the TID entry.
         */
        u32 tidoffset;
        /*
         * KDETH.Offset (Eager) field
         * We need to remember the initial value so the headers
         * can be updated properly.
         */
        u32 koffset;
        u32 sent;
        /* TID index copied from the tid_iov vector */
        u16 tididx;
        /* progress index moving along the iovs array */
        u8 iov_idx;
        u8 has_error;

        struct user_sdma_iovec iovs[MAX_VECTORS_PER_REQ];
} ____cacheline_aligned_in_smp;

/*
 * A single txreq could span up to 3 physical pages when the MTU
 * is sufficiently large (> 4K). Each of the IOV pointers also
 * needs it's own set of flags so the vector has been handled
 * independently of each other.
 */
struct user_sdma_txreq {
        /* Packet header for the txreq */
        struct hfi1_pkt_header hdr;
        struct sdma_txreq txreq;
        struct list_head list;
        struct user_sdma_request *req;
        u16 flags;
        u16 seqnum;
};

int hfi1_user_sdma_alloc_queues(struct hfi1_ctxtdata *uctxt,
                                struct hfi1_filedata *fd);
int hfi1_user_sdma_free_queues(struct hfi1_filedata *fd,
                               struct hfi1_ctxtdata *uctxt);
int hfi1_user_sdma_process_request(struct hfi1_filedata *fd,
                                   struct iovec *iovec, unsigned long dim,
                                   unsigned long *count);
#endif /* _HFI1_USER_SDMA_H */