// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
/* Copyright (c) 2020 Mellanox Technologies Ltd. */

#include <linux/vhost_types.h>
#include <linux/vdpa.h>
#include <linux/gcd.h>
#include <linux/string.h>
#include <linux/mlx5/qp.h>
#include "mlx5_vdpa.h"

/* DIV_ROUND_UP where the divider is a power of 2 give by its log base 2 value */
#define MLX5_DIV_ROUND_UP_POW2(_n, _s) \
({ \
        u64 __s = _s; \
        u64 _res; \
        _res = (((_n) + (1 << (__s)) - 1) >> (__s)); \
        _res; \
})

static int get_octo_len(u64 len, int page_shift)
{
        u64 page_size = 1ULL << page_shift;
        int npages;

        npages = ALIGN(len, page_size) >> page_shift;
        return (npages + 1) / 2;
}

static void mlx5_set_access_mode(void *mkc, int mode)
{
        MLX5_SET(mkc, mkc, access_mode_1_0, mode & 0x3);
        MLX5_SET(mkc, mkc, access_mode_4_2, mode >> 2);
}

static void populate_mtts(struct mlx5_vdpa_direct_mr *mr, __be64 *mtt)
{
        struct scatterlist *sg;
        int nsg = mr->nsg;
        u64 dma_addr;
        u64 dma_len;
        int j = 0;
        int i;

        for_each_sg(mr->sg_head.sgl, sg, mr->nent, i) {
                for (dma_addr = sg_dma_address(sg), dma_len = sg_dma_len(sg);
                     nsg && dma_len;
                     nsg--, dma_addr += BIT(mr->log_size), dma_len -= BIT(mr->log_size))
                        mtt[j++] = cpu_to_be64(dma_addr);
        }
}

struct mlx5_create_mkey_mem {
        u8 out[MLX5_ST_SZ_BYTES(create_mkey_out)];
        u8 in[MLX5_ST_SZ_BYTES(create_mkey_in)];
        __be64 mtt[];
};

struct mlx5_destroy_mkey_mem {
        u8 out[MLX5_ST_SZ_BYTES(destroy_mkey_out)];
        u8 in[MLX5_ST_SZ_BYTES(destroy_mkey_in)];
};

static void fill_create_direct_mr(struct mlx5_vdpa_dev *mvdev,
                                  struct mlx5_vdpa_direct_mr *mr,
                                  struct mlx5_create_mkey_mem *mem)
{
        void *in = &mem->in;
        void *mkc;

        MLX5_SET(create_mkey_in, in, uid, mvdev->res.uid);
        mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
        MLX5_SET(mkc, mkc, lw, !!(mr->perm & VHOST_MAP_WO));
        MLX5_SET(mkc, mkc, lr, !!(mr->perm & VHOST_MAP_RO));
        mlx5_set_access_mode(mkc, MLX5_MKC_ACCESS_MODE_MTT);
        MLX5_SET(mkc, mkc, qpn, 0xffffff);
        MLX5_SET(mkc, mkc, pd, mvdev->res.pdn);
        MLX5_SET64(mkc, mkc, start_addr, mr->offset);
        MLX5_SET64(mkc, mkc, len, mr->end - mr->start);
        MLX5_SET(mkc, mkc, log_page_size, mr->log_size);
        MLX5_SET(mkc, mkc, translations_octword_size,
                 get_octo_len(mr->end - mr->start, mr->log_size));
        MLX5_SET(create_mkey_in, in, translations_octword_actual_size,
                 get_octo_len(mr->end - mr->start, mr->log_size));
        populate_mtts(mr, MLX5_ADDR_OF(create_mkey_in, in, klm_pas_mtt));

        MLX5_SET(create_mkey_in, in, opcode, MLX5_CMD_OP_CREATE_MKEY);
        MLX5_SET(create_mkey_in, in, uid, mvdev->res.uid);
}

static void create_direct_mr_end(struct mlx5_vdpa_dev *mvdev,
                                 struct mlx5_vdpa_direct_mr *mr,
                                 struct mlx5_create_mkey_mem *mem)
{
        u32 mkey_index = MLX5_GET(create_mkey_out, mem->out, mkey_index);

        mr->mr = mlx5_idx_to_mkey(mkey_index);
}

static void fill_destroy_direct_mr(struct mlx5_vdpa_dev *mvdev,
                                   struct mlx5_vdpa_direct_mr *mr,
                                   struct mlx5_destroy_mkey_mem *mem)
{
        void *in = &mem->in;

        MLX5_SET(destroy_mkey_in, in, uid, mvdev->res.uid);
        MLX5_SET(destroy_mkey_in, in, opcode, MLX5_CMD_OP_DESTROY_MKEY);
        MLX5_SET(destroy_mkey_in, in, mkey_index, mlx5_mkey_to_idx(mr->mr));
}

static void destroy_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr *mr)
{
        if (!mr->mr)
                return;

        mlx5_vdpa_destroy_mkey(mvdev, mr->mr);
}

static u64 map_start(struct vhost_iotlb_map *map, struct mlx5_vdpa_direct_mr *mr)
{
        return max_t(u64, map->start, mr->start);
}

static u64 map_end(struct vhost_iotlb_map *map, struct mlx5_vdpa_direct_mr *mr)
{
        return min_t(u64, map->last + 1, mr->end);
}

static u64 maplen(struct vhost_iotlb_map *map, struct mlx5_vdpa_direct_mr *mr)
{
        return map_end(map, mr) - map_start(map, mr);
}

#define MLX5_VDPA_INVALID_START_ADDR ((u64)-1)
#define MLX5_VDPA_INVALID_LEN ((u64)-1)

static u64 indir_start_addr(struct mlx5_vdpa_mr *mkey)
{
        struct mlx5_vdpa_direct_mr *s;

        s = list_first_entry_or_null(&mkey->head, struct mlx5_vdpa_direct_mr, list);
        if (!s)
                return MLX5_VDPA_INVALID_START_ADDR;

        return s->start;
}

static u64 indir_len(struct mlx5_vdpa_mr *mkey)
{
        struct mlx5_vdpa_direct_mr *s;
        struct mlx5_vdpa_direct_mr *e;

        s = list_first_entry_or_null(&mkey->head, struct mlx5_vdpa_direct_mr, list);
        if (!s)
                return MLX5_VDPA_INVALID_LEN;

        e = list_last_entry(&mkey->head, struct mlx5_vdpa_direct_mr, list);

        return e->end - s->start;
}

#define LOG_MAX_KLM_SIZE 30
#define MAX_KLM_SIZE BIT(LOG_MAX_KLM_SIZE)

static u32 klm_bcount(u64 size)
{
        return (u32)size;
}

static void fill_indir(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mkey, void *in)
{
        struct mlx5_vdpa_direct_mr *dmr;
        struct mlx5_klm *klmarr;
        struct mlx5_klm *klm;
        bool first = true;
        u64 preve;
        int i;

        klmarr = MLX5_ADDR_OF(create_mkey_in, in, klm_pas_mtt);
        i = 0;
        list_for_each_entry(dmr, &mkey->head, list) {
again:
                klm = &klmarr[i++];
                if (first) {
                        preve = dmr->start;
                        first = false;
                }

                if (preve == dmr->start) {
                        klm->key = cpu_to_be32(dmr->mr);
                        klm->bcount = cpu_to_be32(klm_bcount(dmr->end - dmr->start));
                        preve = dmr->end;
                } else {
                        u64 bcount = min_t(u64, dmr->start - preve, MAX_KLM_SIZE);

                        klm->key = cpu_to_be32(mvdev->res.null_mkey);
                        klm->bcount = cpu_to_be32(klm_bcount(bcount));
                        preve += bcount;

                        goto again;
                }
        }
}

static int klm_byte_size(int nklms)
{
        return 16 * ALIGN(nklms, 4);
}

#define MLX5_VDPA_MTT_ALIGN 16

static int create_direct_keys(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mr)
{
        struct mlx5_vdpa_async_cmd *cmds;
        struct mlx5_vdpa_direct_mr *dmr;
        int err = 0;
        int i = 0;

        cmds = kvzalloc_objs(*cmds, mr->num_directs);
        if (!cmds)
                return -ENOMEM;

        list_for_each_entry(dmr, &mr->head, list) {
                struct mlx5_create_mkey_mem *cmd_mem;
                int mttlen, mttcount;

                mttlen = roundup(MLX5_ST_SZ_BYTES(mtt) * dmr->nsg, MLX5_VDPA_MTT_ALIGN);
                mttcount = mttlen / sizeof(cmd_mem->mtt[0]);
                cmd_mem = kvcalloc(1, struct_size(cmd_mem, mtt, mttcount), GFP_KERNEL);
                if (!cmd_mem) {
                        err = -ENOMEM;
                        goto done;
                }

                cmds[i].out = cmd_mem->out;
                cmds[i].outlen = sizeof(cmd_mem->out);
                cmds[i].in = cmd_mem->in;
                cmds[i].inlen = struct_size(cmd_mem, mtt, mttcount);

                fill_create_direct_mr(mvdev, dmr, cmd_mem);

                i++;
        }

        err = mlx5_vdpa_exec_async_cmds(mvdev, cmds, mr->num_directs);
        if (err) {

                mlx5_vdpa_err(mvdev, "error issuing MTT mkey creation for direct mrs: %d\n", err);
                goto done;
        }

        i = 0;
        list_for_each_entry(dmr, &mr->head, list) {
                struct mlx5_vdpa_async_cmd *cmd = &cmds[i++];
                struct mlx5_create_mkey_mem *cmd_mem;

                cmd_mem = container_of(cmd->out, struct mlx5_create_mkey_mem, out);

                if (!cmd->err) {
                        create_direct_mr_end(mvdev, dmr, cmd_mem);
                } else {
                        err = err ? err : cmd->err;
                        mlx5_vdpa_err(mvdev, "error creating MTT mkey [0x%llx, 0x%llx]: %d\n",
                                dmr->start, dmr->end, cmd->err);
                }
        }

done:
        for (i = i-1; i >= 0; i--) {
                struct mlx5_create_mkey_mem *cmd_mem;

                cmd_mem = container_of(cmds[i].out, struct mlx5_create_mkey_mem, out);
                kvfree(cmd_mem);
        }

        kvfree(cmds);
        return err;
}

DEFINE_FREE(free_cmds, struct mlx5_vdpa_async_cmd *, kvfree(_T))
DEFINE_FREE(free_cmd_mem, struct mlx5_destroy_mkey_mem *, kvfree(_T))

static int destroy_direct_keys(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mr)
{
        struct mlx5_destroy_mkey_mem *cmd_mem __free(free_cmd_mem) = NULL;
        struct mlx5_vdpa_async_cmd *cmds __free(free_cmds) = NULL;
        struct mlx5_vdpa_direct_mr *dmr;
        int err = 0;
        int i = 0;

        cmds = kvzalloc_objs(*cmds, mr->num_directs);
        cmd_mem = kvzalloc_objs(*cmd_mem, mr->num_directs);
        if (!cmds || !cmd_mem)
                return -ENOMEM;

        list_for_each_entry(dmr, &mr->head, list) {
                cmds[i].out = cmd_mem[i].out;
                cmds[i].outlen = sizeof(cmd_mem[i].out);
                cmds[i].in = cmd_mem[i].in;
                cmds[i].inlen = sizeof(cmd_mem[i].in);
                fill_destroy_direct_mr(mvdev, dmr, &cmd_mem[i]);
                i++;
        }

        err = mlx5_vdpa_exec_async_cmds(mvdev, cmds, mr->num_directs);
        if (err) {

                mlx5_vdpa_err(mvdev, "error issuing MTT mkey deletion for direct mrs: %d\n", err);
                return err;
        }

        i = 0;
        list_for_each_entry(dmr, &mr->head, list) {
                struct mlx5_vdpa_async_cmd *cmd = &cmds[i++];

                dmr->mr = 0;
                if (cmd->err) {
                        err = err ? err : cmd->err;
                        mlx5_vdpa_err(mvdev, "error deleting MTT mkey [0x%llx, 0x%llx]: %d\n",
                                dmr->start, dmr->end, cmd->err);
                }
        }

        return err;
}

static int create_indirect_key(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mr)
{
        int inlen;
        void *mkc;
        void *in;
        int err;
        u64 start;
        u64 len;

        start = indir_start_addr(mr);
        len = indir_len(mr);
        if (start == MLX5_VDPA_INVALID_START_ADDR || len == MLX5_VDPA_INVALID_LEN)
                return -EINVAL;

        inlen = MLX5_ST_SZ_BYTES(create_mkey_in) + klm_byte_size(mr->num_klms);
        in = kzalloc(inlen, GFP_KERNEL);
        if (!in)
                return -ENOMEM;

        MLX5_SET(create_mkey_in, in, uid, mvdev->res.uid);
        mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
        MLX5_SET(mkc, mkc, lw, 1);
        MLX5_SET(mkc, mkc, lr, 1);
        mlx5_set_access_mode(mkc, MLX5_MKC_ACCESS_MODE_KLMS);
        MLX5_SET(mkc, mkc, qpn, 0xffffff);
        MLX5_SET(mkc, mkc, pd, mvdev->res.pdn);
        MLX5_SET64(mkc, mkc, start_addr, start);
        MLX5_SET64(mkc, mkc, len, len);
        MLX5_SET(mkc, mkc, translations_octword_size, klm_byte_size(mr->num_klms) / 16);
        MLX5_SET(create_mkey_in, in, translations_octword_actual_size, mr->num_klms);
        fill_indir(mvdev, mr, in);
        err = mlx5_vdpa_create_mkey(mvdev, &mr->mkey, in, inlen);
        kfree(in);
        return err;
}

static void destroy_indirect_key(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mkey)
{
        mlx5_vdpa_destroy_mkey(mvdev, mkey->mkey);
}

static int map_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr *mr,
                         struct vhost_iotlb *iotlb)
{
        struct vhost_iotlb_map *map;
        unsigned long lgcd = 0;
        int log_entity_size;
        unsigned long size;
        int err;
        struct page *pg;
        unsigned int nsg;
        int sglen;
        u64 pa, offset;
        u64 paend;
        struct scatterlist *sg;
        struct device *dma = mvdev->vdev.vmap.dma_dev;

        for (map = vhost_iotlb_itree_first(iotlb, mr->start, mr->end - 1);
             map; map = vhost_iotlb_itree_next(map, mr->start, mr->end - 1)) {
                size = maplen(map, mr);
                lgcd = gcd(lgcd, size);
        }
        log_entity_size = ilog2(lgcd);

        sglen = 1 << log_entity_size;
        nsg = MLX5_DIV_ROUND_UP_POW2(mr->end - mr->start, log_entity_size);

        err = sg_alloc_table(&mr->sg_head, nsg, GFP_KERNEL);
        if (err)
                return err;

        sg = mr->sg_head.sgl;
        for (map = vhost_iotlb_itree_first(iotlb, mr->start, mr->end - 1);
             map; map = vhost_iotlb_itree_next(map, mr->start, mr->end - 1)) {
                offset = mr->start > map->start ? mr->start - map->start : 0;
                pa = map->addr + offset;
                paend = map->addr + offset + maplen(map, mr);
                for (; pa < paend; pa += sglen) {
                        pg = pfn_to_page(__phys_to_pfn(pa));
                        if (!sg) {
                                mlx5_vdpa_warn(mvdev, "sg null. start 0x%llx, end 0x%llx\n",
                                               map->start, map->last + 1);
                                err = -ENOMEM;
                                goto err_map;
                        }
                        sg_set_page(sg, pg, sglen, 0);
                        sg = sg_next(sg);
                        if (!sg)
                                goto done;
                }
        }
done:
        mr->log_size = log_entity_size;
        mr->nsg = nsg;
        mr->nent = dma_map_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0);
        if (!mr->nent) {
                err = -ENOMEM;
                goto err_map;
        }

        return 0;

err_map:
        sg_free_table(&mr->sg_head);
        return err;
}

static void unmap_direct_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_direct_mr *mr)
{
        struct device *dma = mvdev->vdev.vmap.dma_dev;

        destroy_direct_mr(mvdev, mr);
        dma_unmap_sg_attrs(dma, mr->sg_head.sgl, mr->nsg, DMA_BIDIRECTIONAL, 0);
        sg_free_table(&mr->sg_head);
}

static int add_direct_chain(struct mlx5_vdpa_dev *mvdev,
                            struct mlx5_vdpa_mr *mr,
                            u64 start,
                            u64 size,
                            u8 perm,
                            struct vhost_iotlb *iotlb)
{
        struct mlx5_vdpa_direct_mr *dmr;
        struct mlx5_vdpa_direct_mr *n;
        LIST_HEAD(tmp);
        u64 st;
        u64 sz;
        int err;

        st = start;
        while (size) {
                sz = (u32)min_t(u64, MAX_KLM_SIZE, size);
                dmr = kzalloc_obj(*dmr);
                if (!dmr) {
                        err = -ENOMEM;
                        goto err_alloc;
                }

                dmr->start = st;
                dmr->end = st + sz;
                dmr->perm = perm;
                err = map_direct_mr(mvdev, dmr, iotlb);
                if (err) {
                        kfree(dmr);
                        goto err_alloc;
                }

                list_add_tail(&dmr->list, &tmp);
                size -= sz;
                mr->num_directs++;
                mr->num_klms++;
                st += sz;
        }
        list_splice_tail(&tmp, &mr->head);
        return 0;

err_alloc:
        list_for_each_entry_safe(dmr, n, &mr->head, list) {
                list_del_init(&dmr->list);
                unmap_direct_mr(mvdev, dmr);
                kfree(dmr);
        }
        return err;
}

/* The iotlb pointer contains a list of maps. Go over the maps, possibly
 * merging mergeable maps, and create direct memory keys that provide the
 * device access to memory. The direct mkeys are then referred to by the
 * indirect memory key that provides access to the enitre address space given
 * by iotlb.
 */
static int create_user_mr(struct mlx5_vdpa_dev *mvdev,
                          struct mlx5_vdpa_mr *mr,
                          struct vhost_iotlb *iotlb)
{
        struct mlx5_vdpa_direct_mr *dmr;
        struct mlx5_vdpa_direct_mr *n;
        struct vhost_iotlb_map *map;
        u32 pperm = U16_MAX;
        u64 last = U64_MAX;
        u64 ps = U64_MAX;
        u64 pe = U64_MAX;
        u64 start = 0;
        int err = 0;
        int nnuls;

        INIT_LIST_HEAD(&mr->head);
        for (map = vhost_iotlb_itree_first(iotlb, start, last); map;
             map = vhost_iotlb_itree_next(map, start, last)) {
                start = map->start;
                if (pe == map->start && pperm == map->perm) {
                        pe = map->last + 1;
                } else {
                        if (ps != U64_MAX) {
                                if (pe < map->start) {
                                        /* We have a hole in the map. Check how
                                         * many null keys are required to fill it.
                                         */
                                        nnuls = MLX5_DIV_ROUND_UP_POW2(map->start - pe,
                                                                       LOG_MAX_KLM_SIZE);
                                        mr->num_klms += nnuls;
                                }
                                err = add_direct_chain(mvdev, mr, ps, pe - ps, pperm, iotlb);
                                if (err)
                                        goto err_chain;
                        }
                        ps = map->start;
                        pe = map->last + 1;
                        pperm = map->perm;
                }
        }
        err = add_direct_chain(mvdev, mr, ps, pe - ps, pperm, iotlb);
        if (err)
                goto err_chain;

        err = create_direct_keys(mvdev, mr);
        if (err)
                goto err_chain;

        /* Create the memory key that defines the guests's address space. This
         * memory key refers to the direct keys that contain the MTT
         * translations
         */
        err = create_indirect_key(mvdev, mr);
        if (err)
                goto err_chain;

        mr->user_mr = true;
        return 0;

err_chain:
        list_for_each_entry_safe_reverse(dmr, n, &mr->head, list) {
                list_del_init(&dmr->list);
                unmap_direct_mr(mvdev, dmr);
                kfree(dmr);
        }
        return err;
}

static int create_dma_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mr)
{
        int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
        void *mkc;
        u32 *in;
        int err;

        in = kzalloc(inlen, GFP_KERNEL);
        if (!in)
                return -ENOMEM;

        mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);

        MLX5_SET(mkc, mkc, access_mode_1_0, MLX5_MKC_ACCESS_MODE_PA);
        MLX5_SET(mkc, mkc, length64, 1);
        MLX5_SET(mkc, mkc, lw, 1);
        MLX5_SET(mkc, mkc, lr, 1);
        MLX5_SET(mkc, mkc, pd, mvdev->res.pdn);
        MLX5_SET(mkc, mkc, qpn, 0xffffff);

        err = mlx5_vdpa_create_mkey(mvdev, &mr->mkey, in, inlen);
        if (!err)
                mr->user_mr = false;

        kfree(in);
        return err;
}

static void destroy_dma_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mr)
{
        mlx5_vdpa_destroy_mkey(mvdev, mr->mkey);
}

static int dup_iotlb(struct vhost_iotlb *dst, struct vhost_iotlb *src)
{
        struct vhost_iotlb_map *map;
        u64 start = 0, last = ULLONG_MAX;
        int err;

        if (dst == src)
                return -EINVAL;

        if (!src) {
                err = vhost_iotlb_add_range(dst, start, last, start, VHOST_ACCESS_RW);
                return err;
        }

        for (map = vhost_iotlb_itree_first(src, start, last); map;
                map = vhost_iotlb_itree_next(map, start, last)) {
                err = vhost_iotlb_add_range(dst, map->start, map->last,
                                            map->addr, map->perm);
                if (err)
                        return err;
        }
        return 0;
}

static void prune_iotlb(struct vhost_iotlb *iotlb)
{
        vhost_iotlb_del_range(iotlb, 0, ULLONG_MAX);
}

static void destroy_user_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mr)
{
        struct mlx5_vdpa_direct_mr *dmr;
        struct mlx5_vdpa_direct_mr *n;

        destroy_indirect_key(mvdev, mr);
        destroy_direct_keys(mvdev, mr);
        list_for_each_entry_safe_reverse(dmr, n, &mr->head, list) {
                list_del_init(&dmr->list);
                unmap_direct_mr(mvdev, dmr);
                kfree(dmr);
        }
}

static void _mlx5_vdpa_destroy_mr(struct mlx5_vdpa_dev *mvdev, struct mlx5_vdpa_mr *mr)
{
        if (WARN_ON(!mr))
                return;

        if (mr->user_mr)
                destroy_user_mr(mvdev, mr);
        else
                destroy_dma_mr(mvdev, mr);

        vhost_iotlb_free(mr->iotlb);

        list_del(&mr->mr_list);

        kfree(mr);
}

/* There can be multiple .set_map() operations in quick succession.
 * This large delay is a simple way to prevent the MR cleanup from blocking
 * .set_map() MR creation in this scenario.
 */
#define MLX5_VDPA_MR_GC_TRIGGER_MS 2000

static void mlx5_vdpa_mr_gc_handler(struct work_struct *work)
{
        struct mlx5_vdpa_mr_resources *mres;
        struct mlx5_vdpa_mr *mr, *tmp;
        struct mlx5_vdpa_dev *mvdev;

        mres = container_of(work, struct mlx5_vdpa_mr_resources, gc_dwork_ent.work);

        if (atomic_read(&mres->shutdown)) {
                mutex_lock(&mres->lock);
        } else if (!mutex_trylock(&mres->lock)) {
                queue_delayed_work(mres->wq_gc, &mres->gc_dwork_ent,
                                   msecs_to_jiffies(MLX5_VDPA_MR_GC_TRIGGER_MS));
                return;
        }

        mvdev = container_of(mres, struct mlx5_vdpa_dev, mres);

        list_for_each_entry_safe(mr, tmp, &mres->mr_gc_list_head, mr_list) {
                _mlx5_vdpa_destroy_mr(mvdev, mr);
        }

        mutex_unlock(&mres->lock);
}

static void _mlx5_vdpa_put_mr(struct mlx5_vdpa_dev *mvdev,
                              struct mlx5_vdpa_mr *mr)
{
        struct mlx5_vdpa_mr_resources *mres = &mvdev->mres;

        if (!mr)
                return;

        if (refcount_dec_and_test(&mr->refcount)) {
                list_move_tail(&mr->mr_list, &mres->mr_gc_list_head);
                queue_delayed_work(mres->wq_gc, &mres->gc_dwork_ent,
                                   msecs_to_jiffies(MLX5_VDPA_MR_GC_TRIGGER_MS));
        }
}

void mlx5_vdpa_put_mr(struct mlx5_vdpa_dev *mvdev,
                      struct mlx5_vdpa_mr *mr)
{
        mutex_lock(&mvdev->mres.lock);
        _mlx5_vdpa_put_mr(mvdev, mr);
        mutex_unlock(&mvdev->mres.lock);
}

static void _mlx5_vdpa_get_mr(struct mlx5_vdpa_dev *mvdev,
                              struct mlx5_vdpa_mr *mr)
{
        if (!mr)
                return;

        refcount_inc(&mr->refcount);
}

void mlx5_vdpa_get_mr(struct mlx5_vdpa_dev *mvdev,
                      struct mlx5_vdpa_mr *mr)
{
        mutex_lock(&mvdev->mres.lock);
        _mlx5_vdpa_get_mr(mvdev, mr);
        mutex_unlock(&mvdev->mres.lock);
}

void mlx5_vdpa_update_mr(struct mlx5_vdpa_dev *mvdev,
                         struct mlx5_vdpa_mr *new_mr,
                         unsigned int asid)
{
        struct mlx5_vdpa_mr *old_mr = mvdev->mres.mr[asid];

        mutex_lock(&mvdev->mres.lock);

        _mlx5_vdpa_put_mr(mvdev, old_mr);
        mvdev->mres.mr[asid] = new_mr;

        mutex_unlock(&mvdev->mres.lock);
}

static void mlx5_vdpa_show_mr_leaks(struct mlx5_vdpa_dev *mvdev)
{
        struct mlx5_vdpa_mr *mr;

        mutex_lock(&mvdev->mres.lock);

        list_for_each_entry(mr, &mvdev->mres.mr_list_head, mr_list) {

                mlx5_vdpa_warn(mvdev, "mkey still alive after resource delete: "
                                      "mr: %p, mkey: 0x%x, refcount: %u\n",
                                       mr, mr->mkey, refcount_read(&mr->refcount));
        }

        mutex_unlock(&mvdev->mres.lock);

}

void mlx5_vdpa_clean_mrs(struct mlx5_vdpa_dev *mvdev)
{
        if (!mvdev->res.valid)
                return;

        for (int i = 0; i < MLX5_VDPA_NUM_AS; i++)
                mlx5_vdpa_update_mr(mvdev, NULL, i);

        prune_iotlb(mvdev->cvq.iotlb);

        mlx5_vdpa_show_mr_leaks(mvdev);
}

static int _mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev,
                                struct mlx5_vdpa_mr *mr,
                                struct vhost_iotlb *iotlb)
{
        int err;

        if (iotlb)
                err = create_user_mr(mvdev, mr, iotlb);
        else
                err = create_dma_mr(mvdev, mr);

        if (err)
                return err;

        mr->iotlb = vhost_iotlb_alloc(0, 0);
        if (!mr->iotlb) {
                err = -ENOMEM;
                goto err_mr;
        }

        err = dup_iotlb(mr->iotlb, iotlb);
        if (err)
                goto err_iotlb;

        list_add_tail(&mr->mr_list, &mvdev->mres.mr_list_head);

        return 0;

err_iotlb:
        vhost_iotlb_free(mr->iotlb);

err_mr:
        if (iotlb)
                destroy_user_mr(mvdev, mr);
        else
                destroy_dma_mr(mvdev, mr);

        return err;
}

struct mlx5_vdpa_mr *mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev,
                                         struct vhost_iotlb *iotlb)
{
        struct mlx5_vdpa_mr *mr;
        int err;

        mr = kzalloc_obj(*mr);
        if (!mr)
                return ERR_PTR(-ENOMEM);

        mutex_lock(&mvdev->mres.lock);
        err = _mlx5_vdpa_create_mr(mvdev, mr, iotlb);
        mutex_unlock(&mvdev->mres.lock);

        if (err)
                goto out_err;

        refcount_set(&mr->refcount, 1);

        return mr;

out_err:
        kfree(mr);
        return ERR_PTR(err);
}

int mlx5_vdpa_update_cvq_iotlb(struct mlx5_vdpa_dev *mvdev,
                                struct vhost_iotlb *iotlb,
                                unsigned int asid)
{
        int err;

        if (mvdev->mres.group2asid[MLX5_VDPA_CVQ_GROUP] != asid)
                return 0;

        spin_lock(&mvdev->cvq.iommu_lock);

        prune_iotlb(mvdev->cvq.iotlb);
        err = dup_iotlb(mvdev->cvq.iotlb, iotlb);

        spin_unlock(&mvdev->cvq.iommu_lock);

        return err;
}

int mlx5_vdpa_create_dma_mr(struct mlx5_vdpa_dev *mvdev)
{
        struct mlx5_vdpa_mr *mr;

        mr = mlx5_vdpa_create_mr(mvdev, NULL);
        if (IS_ERR(mr))
                return PTR_ERR(mr);

        mlx5_vdpa_update_mr(mvdev, mr, 0);

        return mlx5_vdpa_update_cvq_iotlb(mvdev, NULL, 0);
}

int mlx5_vdpa_reset_mr(struct mlx5_vdpa_dev *mvdev, unsigned int asid)
{
        if (asid >= MLX5_VDPA_NUM_AS)
                return -EINVAL;

        mlx5_vdpa_update_mr(mvdev, NULL, asid);

        if (asid == 0 && MLX5_CAP_GEN(mvdev->mdev, umem_uid_0)) {
                if (mlx5_vdpa_create_dma_mr(mvdev))
                        mlx5_vdpa_warn(mvdev, "create DMA MR failed\n");
        } else {
                mlx5_vdpa_update_cvq_iotlb(mvdev, NULL, asid);
        }

        return 0;
}

int mlx5_vdpa_init_mr_resources(struct mlx5_vdpa_dev *mvdev)
{
        struct mlx5_vdpa_mr_resources *mres = &mvdev->mres;

        mres->wq_gc = create_singlethread_workqueue("mlx5_vdpa_mr_gc");
        if (!mres->wq_gc)
                return -ENOMEM;

        INIT_DELAYED_WORK(&mres->gc_dwork_ent, mlx5_vdpa_mr_gc_handler);

        mutex_init(&mres->lock);

        INIT_LIST_HEAD(&mres->mr_list_head);
        INIT_LIST_HEAD(&mres->mr_gc_list_head);

        return 0;
}

void mlx5_vdpa_destroy_mr_resources(struct mlx5_vdpa_dev *mvdev)
{
        struct mlx5_vdpa_mr_resources *mres = &mvdev->mres;

        if (!mres->wq_gc)
                return;

        atomic_set(&mres->shutdown, 1);

        flush_delayed_work(&mres->gc_dwork_ent);
        destroy_workqueue(mres->wq_gc);
        mres->wq_gc = NULL;
        mutex_destroy(&mres->lock);
}