// SPDX-License-Identifier: GPL-2.0
#ifndef IOU_RSRC_H
#define IOU_RSRC_H

#include <linux/io_uring_types.h>
#include <linux/lockdep.h>

#define IO_VEC_CACHE_SOFT_CAP           256

enum {
        IORING_RSRC_FILE                = 0,
        IORING_RSRC_BUFFER              = 1,
};

struct io_rsrc_node {
        unsigned char                   type;
        int                             refs;

        u64 tag;
        union {
                unsigned long file_ptr;
                struct io_mapped_ubuf *buf;
        };
};

enum {
        IO_IMU_DEST     = 1 << ITER_DEST,
        IO_IMU_SOURCE   = 1 << ITER_SOURCE,
};

enum {
        IO_REGBUF_F_KBUF                = 1,
};

struct io_mapped_ubuf {
        u64             ubuf;
        unsigned int    len;
        unsigned int    nr_bvecs;
        unsigned int    folio_shift;
        refcount_t      refs;
        unsigned long   acct_pages;
        void            (*release)(void *);
        void            *priv;
        u8              flags;
        u8              dir;
        struct bio_vec  bvec[] __counted_by(nr_bvecs);
};

struct io_imu_folio_data {
        /* Head folio can be partially included in the fixed buf */
        unsigned int    nr_pages_head;
        /* For non-head/tail folios, has to be fully included */
        unsigned int    nr_pages_mid;
        unsigned int    folio_shift;
        unsigned int    nr_folios;
        unsigned long   first_folio_page_idx;
};

bool io_rsrc_cache_init(struct io_ring_ctx *ctx);
void io_rsrc_cache_free(struct io_ring_ctx *ctx);
struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx, int type);
void io_free_rsrc_node(struct io_ring_ctx *ctx, struct io_rsrc_node *node);
void io_rsrc_data_free(struct io_ring_ctx *ctx, struct io_rsrc_data *data);
int io_rsrc_data_alloc(struct io_rsrc_data *data, unsigned nr);

struct io_rsrc_node *io_find_buf_node(struct io_kiocb *req,
                                      unsigned issue_flags);
int io_import_reg_buf(struct io_kiocb *req, struct iov_iter *iter,
                        u64 buf_addr, size_t len, int ddir,
                        unsigned issue_flags);
int io_import_reg_vec(int ddir, struct iov_iter *iter,
                        struct io_kiocb *req, struct iou_vec *vec,
                        unsigned nr_iovs, unsigned issue_flags);
int io_prep_reg_iovec(struct io_kiocb *req, struct iou_vec *iv,
                        const struct iovec __user *uvec, size_t uvec_segs);

int io_register_clone_buffers(struct io_ring_ctx *ctx, void __user *arg);
int io_sqe_buffers_unregister(struct io_ring_ctx *ctx);
int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
                            unsigned int nr_args, u64 __user *tags);
int io_sqe_files_unregister(struct io_ring_ctx *ctx);
int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
                          unsigned nr_args, u64 __user *tags);

int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
                             unsigned nr_args);
int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
                            unsigned size, unsigned type);
int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,
                        unsigned int size, unsigned int type);
int io_validate_user_buf_range(u64 uaddr, u64 ulen);

bool io_check_coalesce_buffer(struct page **page_array, int nr_pages,
                              struct io_imu_folio_data *data);

static inline struct io_rsrc_node *io_rsrc_node_lookup(struct io_rsrc_data *data,
                                                       unsigned int index)
{
        if (index < data->nr)
                return data->nodes[array_index_nospec(index, data->nr)];
        return NULL;
}

static inline void io_put_rsrc_node(struct io_ring_ctx *ctx, struct io_rsrc_node *node)
{
        lockdep_assert_held(&ctx->uring_lock);
        if (!--node->refs)
                io_free_rsrc_node(ctx, node);
}

static inline bool io_reset_rsrc_node(struct io_ring_ctx *ctx,
                                      struct io_rsrc_data *data, int index)
{
        struct io_rsrc_node *node = data->nodes[index];

        if (!node)
                return false;
        io_put_rsrc_node(ctx, node);
        data->nodes[index] = NULL;
        return true;
}

int io_files_update(struct io_kiocb *req, unsigned int issue_flags);
int io_files_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);

int __io_account_mem(struct user_struct *user, unsigned long nr_pages);
int io_account_mem(struct user_struct *user, struct mm_struct *mm_account,
                   unsigned long nr_pages);
void io_unaccount_mem(struct user_struct *user, struct mm_struct *mm_account,
                      unsigned long nr_pages);

static inline void __io_unaccount_mem(struct user_struct *user,
                                      unsigned long nr_pages)
{
        atomic_long_sub(nr_pages, &user->locked_vm);
}

void io_vec_free(struct iou_vec *iv);
int io_vec_realloc(struct iou_vec *iv, unsigned nr_entries);

static inline void io_vec_reset_iovec(struct iou_vec *iv,
                                      struct iovec *iovec, unsigned nr)
{
        io_vec_free(iv);
        iv->iovec = iovec;
        iv->nr = nr;
}

static inline void io_alloc_cache_vec_kasan(struct iou_vec *iv)
{
        if (IS_ENABLED(CONFIG_KASAN))
                io_vec_free(iv);
}

#endif