/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
/* Copyright (C) 2016-2018 Netronome Systems, Inc. */

#ifndef __NFP_BPF_H__
#define __NFP_BPF_H__ 1

#include <linux/bitfield.h>
#include <linux/bpf.h>
#include <linux/bpf_verifier.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/rhashtable.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#include <linux/wait.h>

#include "../ccm.h"
#include "../nfp_asm.h"
#include "fw.h"

#define cmsg_warn(bpf, msg...)  nn_dp_warn(&(bpf)->app->ctrl->dp, msg)

/* For relocation logic use up-most byte of branch instruction as scratch
 * area.  Remember to clear this before sending instructions to HW!
 */
#define OP_RELO_TYPE    0xff00000000000000ULL

enum nfp_relo_type {
        RELO_NONE = 0,
        /* standard internal jumps */
        RELO_BR_REL,
        /* internal jumps to parts of the outro */
        RELO_BR_GO_OUT,
        RELO_BR_GO_ABORT,
        RELO_BR_GO_CALL_PUSH_REGS,
        RELO_BR_GO_CALL_POP_REGS,
        /* external jumps to fixed addresses */
        RELO_BR_NEXT_PKT,
        RELO_BR_HELPER,
        /* immediate relocation against load address */
        RELO_IMMED_REL,
};

/* To make absolute relocated branches (branches other than RELO_BR_REL)
 * distinguishable in user space dumps from normal jumps, add a large offset
 * to them.
 */
#define BR_OFF_RELO             15000

enum static_regs {
        STATIC_REG_IMMA         = 20, /* Bank AB */
        STATIC_REG_IMM          = 21, /* Bank AB */
        STATIC_REG_STACK        = 22, /* Bank A */
        STATIC_REG_PKT_LEN      = 22, /* Bank B */
};

enum pkt_vec {
        PKT_VEC_PKT_LEN         = 0,
        PKT_VEC_PKT_PTR         = 2,
        PKT_VEC_QSEL_SET        = 4,
        PKT_VEC_QSEL_VAL        = 6,
};

#define PKT_VEL_QSEL_SET_BIT    4

#define pv_len(np)      reg_lm(1, PKT_VEC_PKT_LEN)
#define pv_ctm_ptr(np)  reg_lm(1, PKT_VEC_PKT_PTR)
#define pv_qsel_set(np) reg_lm(1, PKT_VEC_QSEL_SET)
#define pv_qsel_val(np) reg_lm(1, PKT_VEC_QSEL_VAL)

#define stack_reg(np)   reg_a(STATIC_REG_STACK)
#define stack_imm(np)   imm_b(np)
#define plen_reg(np)    reg_b(STATIC_REG_PKT_LEN)
#define pptr_reg(np)    pv_ctm_ptr(np)
#define imm_a(np)       reg_a(STATIC_REG_IMM)
#define imm_b(np)       reg_b(STATIC_REG_IMM)
#define imma_a(np)      reg_a(STATIC_REG_IMMA)
#define imma_b(np)      reg_b(STATIC_REG_IMMA)
#define imm_both(np)    reg_both(STATIC_REG_IMM)
#define ret_reg(np)     imm_a(np)

#define NFP_BPF_ABI_FLAGS       reg_imm(0)
#define   NFP_BPF_ABI_FLAG_MARK 1

/**
 * struct nfp_app_bpf - bpf app priv structure
 * @app:                backpointer to the app
 * @ccm:                common control message handler data
 *
 * @bpf_dev:            BPF offload device handle
 *
 * @cmsg_key_sz:        size of key in cmsg element array
 * @cmsg_val_sz:        size of value in cmsg element array
 *
 * @map_list:           list of offloaded maps
 * @maps_in_use:        number of currently offloaded maps
 * @map_elems_in_use:   number of elements allocated to offloaded maps
 *
 * @maps_neutral:       hash table of offload-neutral maps (on pointer)
 *
 * @abi_version:        global BPF ABI version
 * @cmsg_cache_cnt:     number of entries to read for caching
 *
 * @adjust_head:        adjust head capability
 * @adjust_head.flags:          extra flags for adjust head
 * @adjust_head.off_min:        minimal packet offset within buffer required
 * @adjust_head.off_max:        maximum packet offset within buffer required
 * @adjust_head.guaranteed_sub: negative adjustment guaranteed possible
 * @adjust_head.guaranteed_add: positive adjustment guaranteed possible
 *
 * @maps:               map capability
 * @maps.types:                 supported map types
 * @maps.max_maps:              max number of maps supported
 * @maps.max_elems:             max number of entries in each map
 * @maps.max_key_sz:            max size of map key
 * @maps.max_val_sz:            max size of map value
 * @maps.max_elem_sz:           max size of map entry (key + value)
 *
 * @helpers:            helper addressess for various calls
 * @helpers.map_lookup:         map lookup helper address
 * @helpers.map_update:         map update helper address
 * @helpers.map_delete:         map delete helper address
 * @helpers.perf_event_output:  output perf event to a ring buffer
 *
 * @pseudo_random:      FW initialized the pseudo-random machinery (CSRs)
 * @queue_select:       BPF can set the RX queue ID in packet vector
 * @adjust_tail:        BPF can simply trunc packet size for adjust tail
 * @cmsg_multi_ent:     FW can pack multiple map entries in a single cmsg
 */
struct nfp_app_bpf {
        struct nfp_app *app;
        struct nfp_ccm ccm;

        struct bpf_offload_dev *bpf_dev;

        unsigned int cmsg_key_sz;
        unsigned int cmsg_val_sz;

        unsigned int cmsg_cache_cnt;

        struct list_head map_list;
        unsigned int maps_in_use;
        unsigned int map_elems_in_use;

        struct rhashtable maps_neutral;

        u32 abi_version;

        struct nfp_bpf_cap_adjust_head {
                u32 flags;
                int off_min;
                int off_max;
                int guaranteed_sub;
                int guaranteed_add;
        } adjust_head;

        struct {
                u32 types;
                u32 max_maps;
                u32 max_elems;
                u32 max_key_sz;
                u32 max_val_sz;
                u32 max_elem_sz;
        } maps;

        struct {
                u32 map_lookup;
                u32 map_update;
                u32 map_delete;
                u32 perf_event_output;
        } helpers;

        bool pseudo_random;
        bool queue_select;
        bool adjust_tail;
        bool cmsg_multi_ent;
};

enum nfp_bpf_map_use {
        NFP_MAP_UNUSED = 0,
        NFP_MAP_USE_READ,
        NFP_MAP_USE_WRITE,
        NFP_MAP_USE_ATOMIC_CNT,
};

struct nfp_bpf_map_word {
        unsigned char type              :4;
        unsigned char non_zero_update   :1;
};

#define NFP_BPF_MAP_CACHE_CNT           4U
#define NFP_BPF_MAP_CACHE_TIME_NS       (250 * 1000)

/**
 * struct nfp_bpf_map - private per-map data attached to BPF maps for offload
 * @offmap:     pointer to the offloaded BPF map
 * @bpf:        back pointer to bpf app private structure
 * @tid:        table id identifying map on datapath
 *
 * @cache_lock: protects @cache_blockers, @cache_to, @cache
 * @cache_blockers:     number of ops in flight which block caching
 * @cache_gen:  counter incremented by every blocker on exit
 * @cache_to:   time when cache will no longer be valid (ns)
 * @cache:      skb with cached response
 *
 * @l:          link on the nfp_app_bpf->map_list list
 * @use_map:    map of how the value is used (in 4B chunks)
 */
struct nfp_bpf_map {
        struct bpf_offloaded_map *offmap;
        struct nfp_app_bpf *bpf;
        u32 tid;

        spinlock_t cache_lock;
        u32 cache_blockers;
        u32 cache_gen;
        u64 cache_to;
        struct sk_buff *cache;

        struct list_head l;
        struct nfp_bpf_map_word use_map[];
};

struct nfp_bpf_neutral_map {
        struct rhash_head l;
        struct bpf_map *ptr;
        u32 map_id;
        u32 count;
};

extern const struct rhashtable_params nfp_bpf_maps_neutral_params;

struct nfp_prog;
struct nfp_insn_meta;
typedef int (*instr_cb_t)(struct nfp_prog *, struct nfp_insn_meta *);

#define nfp_prog_first_meta(nfp_prog)                                   \
        list_first_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
#define nfp_prog_last_meta(nfp_prog)                                    \
        list_last_entry(&(nfp_prog)->insns, struct nfp_insn_meta, l)
#define nfp_meta_next(meta)     list_next_entry(meta, l)
#define nfp_meta_prev(meta)     list_prev_entry(meta, l)

/**
 * struct nfp_bpf_reg_state - register state for calls
 * @reg: BPF register state from latest path
 * @var_off: for stack arg - changes stack offset on different paths
 */
struct nfp_bpf_reg_state {
        struct bpf_reg_state reg;
        bool var_off;
};

#define FLAG_INSN_IS_JUMP_DST                   BIT(0)
#define FLAG_INSN_IS_SUBPROG_START              BIT(1)
#define FLAG_INSN_PTR_CALLER_STACK_FRAME        BIT(2)
/* Instruction is pointless, noop even on its own */
#define FLAG_INSN_SKIP_NOOP                     BIT(3)
/* Instruction is optimized out based on preceding instructions */
#define FLAG_INSN_SKIP_PREC_DEPENDENT           BIT(4)
/* Instruction is optimized by the verifier */
#define FLAG_INSN_SKIP_VERIFIER_OPT             BIT(5)
/* Instruction needs to zero extend to high 32-bit */
#define FLAG_INSN_DO_ZEXT                       BIT(6)

#define FLAG_INSN_SKIP_MASK             (FLAG_INSN_SKIP_NOOP | \
                                         FLAG_INSN_SKIP_PREC_DEPENDENT | \
                                         FLAG_INSN_SKIP_VERIFIER_OPT)

/**
 * struct nfp_insn_meta - BPF instruction wrapper
 * @insn: BPF instruction
 * @ptr: pointer type for memory operations
 * @ldst_gather_len: memcpy length gathered from load/store sequence
 * @paired_st: the paired store insn at the head of the sequence
 * @ptr_not_const: pointer is not always constant
 * @pkt_cache: packet data cache information
 * @pkt_cache.range_start: start offset for associated packet data cache
 * @pkt_cache.range_end: end offset for associated packet data cache
 * @pkt_cache.do_init: this read needs to initialize packet data cache
 * @xadd_over_16bit: 16bit immediate is not guaranteed
 * @xadd_maybe_16bit: 16bit immediate is possible
 * @jmp_dst: destination info for jump instructions
 * @jump_neg_op: jump instruction has inverted immediate, use ADD instead of SUB
 * @num_insns_after_br: number of insns following a branch jump, used for fixup
 * @func_id: function id for call instructions
 * @arg1: arg1 for call instructions
 * @arg2: arg2 for call instructions
 * @umin_src: copy of core verifier umin_value for src opearnd.
 * @umax_src: copy of core verifier umax_value for src operand.
 * @umin_dst: copy of core verifier umin_value for dst opearnd.
 * @umax_dst: copy of core verifier umax_value for dst operand.
 * @off: index of first generated machine instruction (in nfp_prog.prog)
 * @n: eBPF instruction number
 * @flags: eBPF instruction extra optimization flags
 * @subprog_idx: index of subprogram to which the instruction belongs
 * @double_cb: callback for second part of the instruction
 * @l: link on nfp_prog->insns list
 */
struct nfp_insn_meta {
        struct bpf_insn insn;
        union {
                /* pointer ops (ld/st/xadd) */
                struct {
                        struct bpf_reg_state ptr;
                        struct bpf_insn *paired_st;
                        s16 ldst_gather_len;
                        bool ptr_not_const;
                        struct {
                                s16 range_start;
                                s16 range_end;
                                bool do_init;
                        } pkt_cache;
                        bool xadd_over_16bit;
                        bool xadd_maybe_16bit;
                };
                /* jump */
                struct {
                        struct nfp_insn_meta *jmp_dst;
                        bool jump_neg_op;
                        u32 num_insns_after_br; /* only for BPF-to-BPF calls */
                };
                /* function calls */
                struct {
                        u32 func_id;
                        struct bpf_reg_state arg1;
                        struct nfp_bpf_reg_state arg2;
                };
                /* We are interested in range info for operands of ALU
                 * operations. For example, shift amount, multiplicand and
                 * multiplier etc.
                 */
                struct {
                        u64 umin_src;
                        u64 umax_src;
                        u64 umin_dst;
                        u64 umax_dst;
                };
        };
        unsigned int off;
        unsigned short n;
        unsigned short flags;
        unsigned short subprog_idx;
        instr_cb_t double_cb;

        struct list_head l;
};

#define BPF_SIZE_MASK   0x18

static inline u8 mbpf_class(const struct nfp_insn_meta *meta)
{
        return BPF_CLASS(meta->insn.code);
}

static inline u8 mbpf_src(const struct nfp_insn_meta *meta)
{
        return BPF_SRC(meta->insn.code);
}

static inline u8 mbpf_op(const struct nfp_insn_meta *meta)
{
        return BPF_OP(meta->insn.code);
}

static inline u8 mbpf_mode(const struct nfp_insn_meta *meta)
{
        return BPF_MODE(meta->insn.code);
}

static inline bool is_mbpf_alu(const struct nfp_insn_meta *meta)
{
        return mbpf_class(meta) == BPF_ALU64 || mbpf_class(meta) == BPF_ALU;
}

static inline bool is_mbpf_load(const struct nfp_insn_meta *meta)
{
        return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM);
}

static inline bool is_mbpf_jmp32(const struct nfp_insn_meta *meta)
{
        return mbpf_class(meta) == BPF_JMP32;
}

static inline bool is_mbpf_jmp64(const struct nfp_insn_meta *meta)
{
        return mbpf_class(meta) == BPF_JMP;
}

static inline bool is_mbpf_jmp(const struct nfp_insn_meta *meta)
{
        return is_mbpf_jmp32(meta) || is_mbpf_jmp64(meta);
}

static inline bool is_mbpf_store(const struct nfp_insn_meta *meta)
{
        return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM);
}

static inline bool is_mbpf_load_pkt(const struct nfp_insn_meta *meta)
{
        return is_mbpf_load(meta) && meta->ptr.type == PTR_TO_PACKET;
}

static inline bool is_mbpf_store_pkt(const struct nfp_insn_meta *meta)
{
        return is_mbpf_store(meta) && meta->ptr.type == PTR_TO_PACKET;
}

static inline bool is_mbpf_classic_load(const struct nfp_insn_meta *meta)
{
        u8 code = meta->insn.code;

        return BPF_CLASS(code) == BPF_LD &&
               (BPF_MODE(code) == BPF_ABS || BPF_MODE(code) == BPF_IND);
}

static inline bool is_mbpf_classic_store(const struct nfp_insn_meta *meta)
{
        u8 code = meta->insn.code;

        return BPF_CLASS(code) == BPF_ST && BPF_MODE(code) == BPF_MEM;
}

static inline bool is_mbpf_classic_store_pkt(const struct nfp_insn_meta *meta)
{
        return is_mbpf_classic_store(meta) && meta->ptr.type == PTR_TO_PACKET;
}

static inline bool is_mbpf_atomic(const struct nfp_insn_meta *meta)
{
        return (meta->insn.code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_ATOMIC);
}

static inline bool is_mbpf_mul(const struct nfp_insn_meta *meta)
{
        return is_mbpf_alu(meta) && mbpf_op(meta) == BPF_MUL;
}

static inline bool is_mbpf_div(const struct nfp_insn_meta *meta)
{
        return is_mbpf_alu(meta) && mbpf_op(meta) == BPF_DIV;
}

static inline bool is_mbpf_cond_jump(const struct nfp_insn_meta *meta)
{
        u8 op;

        if (is_mbpf_jmp32(meta))
                return true;

        if (!is_mbpf_jmp64(meta))
                return false;

        op = mbpf_op(meta);
        return op != BPF_JA && op != BPF_EXIT && op != BPF_CALL;
}

static inline bool is_mbpf_helper_call(const struct nfp_insn_meta *meta)
{
        struct bpf_insn insn = meta->insn;

        return insn.code == (BPF_JMP | BPF_CALL) &&
                insn.src_reg != BPF_PSEUDO_CALL;
}

static inline bool is_mbpf_pseudo_call(const struct nfp_insn_meta *meta)
{
        struct bpf_insn insn = meta->insn;

        return insn.code == (BPF_JMP | BPF_CALL) &&
                insn.src_reg == BPF_PSEUDO_CALL;
}

#define STACK_FRAME_ALIGN 64

/**
 * struct nfp_bpf_subprog_info - nfp BPF sub-program (a.k.a. function) info
 * @stack_depth:        maximum stack depth used by this sub-program
 * @needs_reg_push:     whether sub-program uses callee-saved registers
 */
struct nfp_bpf_subprog_info {
        u16 stack_depth;
        u8 needs_reg_push : 1;
};

/**
 * struct nfp_prog - nfp BPF program
 * @bpf: backpointer to the bpf app priv structure
 * @prog: machine code
 * @prog_len: number of valid instructions in @prog array
 * @__prog_alloc_len: alloc size of @prog array
 * @stack_size: total amount of stack used
 * @verifier_meta: temporary storage for verifier's insn meta
 * @type: BPF program type
 * @last_bpf_off: address of the last instruction translated from BPF
 * @tgt_out: jump target for normal exit
 * @tgt_abort: jump target for abort (e.g. access outside of packet buffer)
 * @tgt_call_push_regs: jump target for subroutine for saving R6~R9 to stack
 * @tgt_call_pop_regs: jump target for subroutine used for restoring R6~R9
 * @n_translated: number of successfully translated instructions (for errors)
 * @error: error code if something went wrong
 * @stack_frame_depth: max stack depth for current frame
 * @adjust_head_location: if program has single adjust head call - the insn no.
 * @map_records_cnt: the number of map pointers recorded for this prog
 * @subprog_cnt: number of sub-programs, including main function
 * @map_records: the map record pointers from bpf->maps_neutral
 * @subprog: pointer to an array of objects holding info about sub-programs
 * @n_insns: number of instructions on @insns list
 * @insns: list of BPF instruction wrappers (struct nfp_insn_meta)
 */
struct nfp_prog {
        struct nfp_app_bpf *bpf;

        u64 *prog;
        unsigned int prog_len;
        unsigned int __prog_alloc_len;

        unsigned int stack_size;

        struct nfp_insn_meta *verifier_meta;

        enum bpf_prog_type type;

        unsigned int last_bpf_off;
        unsigned int tgt_out;
        unsigned int tgt_abort;
        unsigned int tgt_call_push_regs;
        unsigned int tgt_call_pop_regs;

        unsigned int n_translated;
        int error;

        unsigned int stack_frame_depth;
        unsigned int adjust_head_location;

        unsigned int map_records_cnt;
        unsigned int subprog_cnt;
        struct nfp_bpf_neutral_map **map_records;
        struct nfp_bpf_subprog_info *subprog;

        unsigned int n_insns;
        struct list_head insns;
};

/**
 * struct nfp_bpf_vnic - per-vNIC BPF priv structure
 * @tc_prog:    currently loaded cls_bpf program
 * @start_off:  address of the first instruction in the memory
 * @tgt_done:   jump target to get the next packet
 */
struct nfp_bpf_vnic {
        struct bpf_prog *tc_prog;
        unsigned int start_off;
        unsigned int tgt_done;
};

bool nfp_is_subprog_start(struct nfp_insn_meta *meta);
void nfp_bpf_jit_prepare(struct nfp_prog *nfp_prog);
int nfp_bpf_jit(struct nfp_prog *prog);
bool nfp_bpf_supported_opcode(u8 code);
bool nfp_bpf_offload_check_mtu(struct nfp_net *nn, struct bpf_prog *prog,
                               unsigned int mtu);

int nfp_verify_insn(struct bpf_verifier_env *env, int insn_idx,
                    int prev_insn_idx);
int nfp_bpf_finalize(struct bpf_verifier_env *env);

int nfp_bpf_opt_replace_insn(struct bpf_verifier_env *env, u32 off,
                             struct bpf_insn *insn);
int nfp_bpf_opt_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt);

extern const struct bpf_prog_offload_ops nfp_bpf_dev_ops;

struct netdev_bpf;
struct nfp_app;
struct nfp_net;

int nfp_ndo_bpf(struct nfp_app *app, struct nfp_net *nn,
                struct netdev_bpf *bpf);
int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
                        bool old_prog, struct netlink_ext_ack *extack);

struct nfp_insn_meta *
nfp_bpf_goto_meta(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta,
                  unsigned int insn_idx);

void *nfp_bpf_relo_for_vnic(struct nfp_prog *nfp_prog, struct nfp_bpf_vnic *bv);

unsigned int nfp_bpf_ctrl_cmsg_min_mtu(struct nfp_app_bpf *bpf);
unsigned int nfp_bpf_ctrl_cmsg_mtu(struct nfp_app_bpf *bpf);
unsigned int nfp_bpf_ctrl_cmsg_cache_cnt(struct nfp_app_bpf *bpf);
long long int
nfp_bpf_ctrl_alloc_map(struct nfp_app_bpf *bpf, struct bpf_map *map);
void
nfp_bpf_ctrl_free_map(struct nfp_app_bpf *bpf, struct nfp_bpf_map *nfp_map);
int nfp_bpf_ctrl_getfirst_entry(struct bpf_offloaded_map *offmap,
                                void *next_key);
int nfp_bpf_ctrl_update_entry(struct bpf_offloaded_map *offmap,
                              void *key, void *value, u64 flags);
int nfp_bpf_ctrl_del_entry(struct bpf_offloaded_map *offmap, void *key);
int nfp_bpf_ctrl_lookup_entry(struct bpf_offloaded_map *offmap,
                              void *key, void *value);
int nfp_bpf_ctrl_getnext_entry(struct bpf_offloaded_map *offmap,
                               void *key, void *next_key);

int nfp_bpf_event_output(struct nfp_app_bpf *bpf, const void *data,
                         unsigned int len);

void nfp_bpf_ctrl_msg_rx(struct nfp_app *app, struct sk_buff *skb);
void
nfp_bpf_ctrl_msg_rx_raw(struct nfp_app *app, const void *data,
                        unsigned int len);
#endif