/*      $OpenBSD: uvm_pmemrange.h,v 1.21 2026/07/24 15:03:50 kettenis Exp $     */

/*
 * Copyright (c) 2009 Ariane van der Steldt <ariane@stack.nl>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * uvm_pmemrange.h: describe and manage free physical memory.
 */

#ifndef _UVM_UVM_PMEMRANGE_H_
#define _UVM_UVM_PMEMRANGE_H_

RBT_HEAD(uvm_pmr_addr, vm_page);
RBT_HEAD(uvm_pmr_size, vm_page);

/*
 * Page types available:
 * - DIRTY: this page may contain random data.
 * - ZERO: this page has been zeroed.
 */
#define UVM_PMR_MEMTYPE_DIRTY   0
#define UVM_PMR_MEMTYPE_ZERO    1
#define UVM_PMR_MEMTYPE_MAX     2

/*
 * An address range of memory.
 */
struct uvm_pmemrange {
        struct  uvm_pmr_addr addr;      /* Free page chunks, sorted by addr. */
        struct  uvm_pmr_size size[UVM_PMR_MEMTYPE_MAX];
                                        /* Free page chunks, sorted by size. */
        TAILQ_HEAD(, vm_page) single[UVM_PMR_MEMTYPE_MAX];
                                        /* single page regions (uses pageq) */

        paddr_t low;                    /* Start of address range (pgno). */
        paddr_t high;                   /* End +1 (pgno). */
        int     use;                    /* Use counter. */
        psize_t nsegs;                  /* Current range count. */

        TAILQ_ENTRY(uvm_pmemrange) pmr_use;
                                        /* pmr, sorted by use */
        RBT_ENTRY(uvm_pmemrange) pmr_addr;
                                        /* pmr, sorted by address */
};

RBT_HEAD(uvm_pmemrange_addr, uvm_pmemrange);
TAILQ_HEAD(uvm_pmemrange_use, uvm_pmemrange);

/*
 * pmr control structure. Contained in uvm.pmr_control.
 */
struct uvm_pmr_control {
        struct  uvm_pmemrange_addr addr;
        struct  uvm_pmemrange_use use;
};

void    uvm_pmr_freepages(struct vm_page *, psize_t);
void    uvm_pmr_freepageq(struct pglist *);
int     uvm_pmr_getpages(psize_t, paddr_t, paddr_t, paddr_t, paddr_t,
            int, int, struct pglist *);
void    uvm_pmr_init(void);
int     uvm_wait_pla(paddr_t, paddr_t, paddr_t, int);
void    uvm_wakeup_pla(paddr_t, psize_t);

#if defined(DDB) || defined(DEBUG)
int     uvm_pmr_isfree(struct vm_page *pg);
#endif

/*
 * Internal tree logic.
 */

int     uvm_pmr_addr_cmp(const struct vm_page *, const struct vm_page *);
int     uvm_pmr_size_cmp(const struct vm_page *, const struct vm_page *);

RBT_PROTOTYPE(uvm_pmr_addr, vm_page, objt, uvm_pmr_addr_cmp);
RBT_PROTOTYPE(uvm_pmr_size, vm_page, objt, uvm_pmr_size_cmp);
RBT_PROTOTYPE(uvm_pmemrange_addr, uvm_pmemrange, pmr_addr,
    uvm_pmemrange_addr_cmp);

struct vm_page          *uvm_pmr_insert_addr(struct uvm_pmemrange *,
                            struct vm_page *, int);
void                     uvm_pmr_insert_size(struct uvm_pmemrange *,
                            struct vm_page *);
struct vm_page          *uvm_pmr_insert(struct uvm_pmemrange *,
                            struct vm_page *, int);
void                     uvm_pmr_remove_addr(struct uvm_pmemrange *,
                            struct vm_page *);
void                     uvm_pmr_remove_size(struct uvm_pmemrange *,
                            struct vm_page *);
void                     uvm_pmr_remove(struct uvm_pmemrange *,
                            struct vm_page *);
struct vm_page          *uvm_pmr_extract_range(struct uvm_pmemrange *,
                            struct vm_page *, paddr_t, paddr_t,
                            struct pglist *);
struct vm_page          *uvm_pmr_cache_get(int);
void                     uvm_pmr_cache_put(struct vm_page *);
unsigned int             uvm_pmr_cache_drain(void);


#endif /* _UVM_UVM_PMEMRANGE_H_ */