/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2013 The FreeBSD Foundation
 *
 * This software was developed by Konstantin Belousov <kib@FreeBSD.org>
 * under sponsorship from the FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef _DEV_IOMMU_IOMMU_H_
#define _DEV_IOMMU_IOMMU_H_

#include <sys/_task.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <dev/iommu/iommu_types.h>
#include <dev/pci/pcireg.h>

struct bus_dma_tag_common;
struct iommu_map_entry;
TAILQ_HEAD(iommu_map_entries_tailq, iommu_map_entry);

RB_HEAD(iommu_gas_entries_tree, iommu_map_entry);
RB_PROTOTYPE(iommu_gas_entries_tree, iommu_map_entry, rb_entry,
    iommu_gas_cmp_entries);

struct iommu_qi_genseq {
        u_int gen;
        uint32_t seq;
};

struct iommu_map_entry {
        iommu_gaddr_t start;
        iommu_gaddr_t end;
        iommu_gaddr_t first;            /* Least start in subtree */
        iommu_gaddr_t last;             /* Greatest end in subtree */
        iommu_gaddr_t free_down;        /* Max free space below the
                                           current R/B tree node */
        u_int flags;
        union {
                TAILQ_ENTRY(iommu_map_entry) dmamap_link; /* DMA map entries */
                struct iommu_map_entry *tlb_flush_next;
        };
        RB_ENTRY(iommu_map_entry) rb_entry;      /* Links for domain entries */
        struct iommu_domain *domain;
        struct iommu_qi_genseq gseq;
        struct spglist pgtbl_free;
};

struct iommu_unit {
        struct mtx lock;
        device_t dev;
        int unit;
        struct sysctl_ctx_list sysctl_ctx;

        int dma_enabled;

        /* Busdma delayed map load */
        struct task dmamap_load_task;
        TAILQ_HEAD(, bus_dmamap_iommu) delayed_maps;
        struct taskqueue *delayed_taskqueue;

        /*
         * Bitmap of buses for which context must ignore slot:func,
         * duplicating the page table pointer into all context table
         * entries.  This is a client-controlled quirk to support some
         * NTBs.
         */
        uint32_t buswide_ctxs[(PCI_BUSMAX + 1) / NBBY / sizeof(uint32_t)];
};

struct iommu_domain_map_ops {
        int (*map)(struct iommu_domain *domain, struct iommu_map_entry *entry,
            vm_page_t *ma, uint64_t pflags, int flags);
        int (*unmap)(struct iommu_domain *domain, struct iommu_map_entry *entry,
            int flags);
};

/*
 * Locking annotations:
 * (u) - Protected by iommu unit lock
 * (d) - Protected by domain lock
 * (c) - Immutable after initialization
 */

struct iommu_domain {
        struct iommu_unit *iommu;       /* (c) */
        const struct iommu_domain_map_ops *ops;
        struct mtx lock;                /* (c) */
        struct task unload_task;        /* (c) */
        u_int entries_cnt;              /* (d) */
        struct iommu_map_entries_tailq unload_entries; /* (d) Entries to
                                                         unload */
        struct iommu_gas_entries_tree rb_root; /* (d) */
        struct iommu_map_entry *start_gap;     /* (d) */
        iommu_gaddr_t end;              /* (c) Highest address + 1 in
                                           the guest AS */
        struct iommu_map_entry *first_place, *last_place; /* (d) */
        struct iommu_map_entry *msi_entry; /* (d) Arch-specific */
        iommu_gaddr_t msi_base;         /* (d) Arch-specific */
        vm_paddr_t msi_phys;            /* (d) Arch-specific */
        u_int flags;                    /* (u) */
        LIST_HEAD(, iommu_ctx) contexts;/* (u) */
};

struct iommu_ctx {
        struct iommu_domain *domain;    /* (c) */
        struct bus_dma_tag_iommu *tag;  /* (c) Root tag */
        LIST_ENTRY(iommu_ctx) link;     /* (u) Member in the domain list */
        u_int refs;                     /* (u) References from tags */
        u_long loads;                   /* atomic updates, for stat only */
        u_long unloads;                 /* same */
        u_int flags;                    /* (u) */
        uint16_t rid;                   /* (c) pci RID */
};

/* struct iommu_ctx flags */
#define IOMMU_CTX_FAULTED       0x0001  /* Fault was reported,
                                           last_fault_rec is valid */
#define IOMMU_CTX_DISABLED      0x0002  /* Device is disabled, the
                                           ephemeral reference is kept
                                           to prevent context destruction */

#define IOMMU_DOMAIN_GAS_INITED         0x0001
#define IOMMU_DOMAIN_PGTBL_INITED       0x0002
#define IOMMU_DOMAIN_IDMAP              0x0010  /* Domain uses identity
                                                   page table */
#define IOMMU_DOMAIN_RMRR               0x0020  /* Domain contains RMRR entry,
                                                   cannot be turned off */

#define IOMMU_LOCK(unit)                mtx_lock(&(unit)->lock)
#define IOMMU_UNLOCK(unit)              mtx_unlock(&(unit)->lock)
#define IOMMU_ASSERT_LOCKED(unit)       mtx_assert(&(unit)->lock, MA_OWNED)

#define IOMMU_DOMAIN_LOCK(dom)          mtx_lock(&(dom)->lock)
#define IOMMU_DOMAIN_UNLOCK(dom)        mtx_unlock(&(dom)->lock)
#define IOMMU_DOMAIN_ASSERT_LOCKED(dom) mtx_assert(&(dom)->lock, MA_OWNED)

void iommu_free_ctx(struct iommu_ctx *ctx);
void iommu_free_ctx_locked(struct iommu_unit *iommu, struct iommu_ctx *ctx);
struct iommu_ctx *iommu_get_ctx(struct iommu_unit *, device_t dev,
    uint16_t rid, bool id_mapped, bool rmrr_init);
struct iommu_unit *iommu_find(device_t dev, bool verbose);
void iommu_domain_unload_entry(struct iommu_map_entry *entry, bool free,
    bool cansleep);
void iommu_domain_unload(struct iommu_domain *domain,
    struct iommu_map_entries_tailq *entries, bool cansleep);

void iommu_unit_pre_instantiate_ctx(struct iommu_unit *iommu);
struct iommu_ctx *iommu_instantiate_ctx(struct iommu_unit *iommu,
    device_t dev, bool rmrr);
int iommu_get_requester(device_t dev, device_t *requester, uint16_t *rid);
int iommu_init_busdma(struct iommu_unit *unit);
void iommu_fini_busdma(struct iommu_unit *unit);

void iommu_gas_init_domain(struct iommu_domain *domain);
void iommu_gas_fini_domain(struct iommu_domain *domain);
struct iommu_map_entry *iommu_gas_alloc_entry(struct iommu_domain *domain,
    u_int flags);
void iommu_gas_free_entry(struct iommu_map_entry *entry);
void iommu_gas_free_space(struct iommu_map_entry *entry);
void iommu_gas_remove(struct iommu_domain *domain, iommu_gaddr_t start,
    iommu_gaddr_t size);
int iommu_gas_map(struct iommu_domain *domain,
    const struct bus_dma_tag_common *common, iommu_gaddr_t size, int offset,
    u_int eflags, u_int flags, vm_page_t *ma, struct iommu_map_entry **res);
void iommu_gas_free_region(struct iommu_map_entry *entry);
int iommu_gas_map_region(struct iommu_domain *domain,
    struct iommu_map_entry *entry, u_int eflags, u_int flags, vm_page_t *ma);
int iommu_gas_reserve_region(struct iommu_domain *domain, iommu_gaddr_t start,
    iommu_gaddr_t end, struct iommu_map_entry **entry0);
int iommu_gas_reserve_region_extend(struct iommu_domain *domain,
    iommu_gaddr_t start, iommu_gaddr_t end);

void iommu_set_buswide_ctx(struct iommu_unit *unit, u_int busno);
bool iommu_is_buswide_ctx(struct iommu_unit *unit, u_int busno);
void iommu_domain_init(struct iommu_unit *unit, struct iommu_domain *domain,
    const struct iommu_domain_map_ops *ops);
void iommu_domain_fini(struct iommu_domain *domain);

bool bus_dma_iommu_set_buswide(device_t dev);
int bus_dma_iommu_load_ident(bus_dma_tag_t dmat, bus_dmamap_t map,
    vm_paddr_t start, vm_size_t length, int flags);

bus_dma_tag_t iommu_get_dma_tag(device_t dev, device_t child);
struct iommu_ctx *iommu_get_dev_ctx(device_t dev);
struct iommu_domain *iommu_get_ctx_domain(struct iommu_ctx *ctx);

SYSCTL_DECL(_hw_iommu);

#endif /* !_DEV_IOMMU_IOMMU_H_ */