/*      $OpenBSD: qcsmem.c,v 1.2 2026/02/06 21:35:16 kettenis Exp $     */
/*
 * Copyright (c) 2023 Patrick Wildt <patrick@blueri.se>
 *
 * 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.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/malloc.h>
#include <sys/atomic.h>

#include <machine/bus.h>
#include <machine/fdt.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_misc.h>
#include <dev/ofw/fdt.h>

#define QCSMEM_ITEM_FIXED       8
#define QCSMEM_ITEM_COUNT       512
#define QCSMEM_HOST_COUNT       15

struct qcsmem_proc_comm {
        uint32_t command;
        uint32_t status;
        uint32_t params[2];
};

struct qcsmem_global_entry {
        uint32_t allocated;
        uint32_t offset;
        uint32_t size;
        uint32_t aux_base;
#define QCSMEM_GLOBAL_ENTRY_AUX_BASE_MASK       0xfffffffc
};

struct qcsmem_header {
        struct qcsmem_proc_comm proc_comm[4];
        uint32_t version[32];
#define QCSMEM_HEADER_VERSION_MASTER_SBL_IDX    7
#define QCSMEM_HEADER_VERSION_GLOBAL_HEAP       11
#define QCSMEM_HEADER_VERSION_GLOBAL_PART       12
        uint32_t initialized;
        uint32_t free_offset;
        uint32_t available;
        uint32_t reserved;
        struct qcsmem_global_entry toc[QCSMEM_ITEM_COUNT];
};

struct qcsmem_ptable_entry {
        uint32_t offset;
        uint32_t size;
        uint32_t flags;
        uint16_t host[2];
#define QCSMEM_LOCAL_HOST                       0
#define QCSMEM_GLOBAL_HOST                      0xfffe
        uint32_t cacheline;
        uint32_t reserved[7];
};

struct qcsmem_ptable {
        uint32_t magic;
#define QCSMEM_PTABLE_MAGIC     0x434f5424
        uint32_t version;
#define QCSMEM_PTABLE_VERSION   1
        uint32_t num_entries;
        uint32_t reserved[5];
        struct qcsmem_ptable_entry entry[];
};

struct qcsmem_partition_header {
        uint32_t magic;
#define QCSMEM_PART_HDR_MAGIC   0x54525024
        uint16_t host[2];
        uint32_t size;
        uint32_t offset_free_uncached;
        uint32_t offset_free_cached;
        uint32_t reserved[3];
};

struct qcsmem_partition {
        struct qcsmem_partition_header *phdr;
        size_t cacheline;
        size_t size;
};

struct qcsmem_private_entry {
        uint16_t canary;
#define QCSMEM_PRIV_ENTRY_CANARY        0xa5a5
        uint16_t item;
        uint32_t size;
        uint16_t padding_data;
        uint16_t padding_hdr;
        uint32_t reserved;
};

struct qcsmem_info {
        uint32_t magic;
#define QCSMEM_INFO_MAGIC       0x49494953
        uint32_t size;
        uint32_t base_addr;
        uint32_t reserved;
        uint32_t num_items;
};

struct qcsmem_softc {
        struct device           sc_dev;
        bus_space_tag_t         sc_iot;
        bus_space_handle_t      sc_ioh;
        int                     sc_node;

        bus_addr_t              sc_aux_base;
        bus_size_t              sc_aux_size;

        int                     sc_item_count;
        struct qcsmem_partition sc_global_partition;
        struct qcsmem_partition sc_partitions[QCSMEM_HOST_COUNT];
};

struct qcsmem_softc *qcsmem_sc;

int     qcsmem_match(struct device *, void *, void *);
void    qcsmem_attach(struct device *, struct device *, void *);

const struct cfattach qcsmem_ca = {
        sizeof (struct qcsmem_softc), qcsmem_match, qcsmem_attach
};

struct cfdriver qcsmem_cd = {
        NULL, "qcsmem", DV_DULL
};

int
qcsmem_match(struct device *parent, void *match, void *aux)
{
        struct fdt_attach_args *faa = aux;

        return OF_is_compatible(faa->fa_node, "qcom,smem");
}

void
qcsmem_attach(struct device *parent, struct device *self, void *aux)
{
        struct qcsmem_softc *sc = (struct qcsmem_softc *)self;
        struct fdt_attach_args *faa = aux;
        struct qcsmem_header *header;
        struct qcsmem_ptable *ptable;
        struct qcsmem_ptable_entry *pte;
        struct qcsmem_info *info;
        struct qcsmem_partition *part;
        struct qcsmem_partition_header *phdr;
        uint32_t version;
        uint32_t memreg;
        uint32_t reg[4];
        int i, node;

        memreg = OF_getpropint(faa->fa_node, "memory-region", 0);
        if (memreg) {
                node = OF_getnodebyphandle(memreg);
                if (node == 0) {
                        printf(": can't find memory region\n");
                        return;
                }
                if (OF_getpropintarray(node, "reg", reg,
                    sizeof(reg)) != sizeof(reg)) {
                        printf(": no registers\n");
                        return;
                }
                sc->sc_aux_base = (bus_addr_t)reg[0] << 32 | reg[1];
                sc->sc_aux_size = (bus_size_t)reg[2] << 32 | reg[3];
        } else {
                if (faa->fa_nreg < 1) {
                        printf(": no registers\n");
                        return;
                }
                sc->sc_aux_base = faa->fa_reg[0].addr;
                sc->sc_aux_size = faa->fa_reg[0].size;
        }

        sc->sc_node = faa->fa_node;
        sc->sc_iot = faa->fa_iot;
        if (bus_space_map(sc->sc_iot, sc->sc_aux_base, sc->sc_aux_size,
            BUS_SPACE_MAP_LINEAR, &sc->sc_ioh)) {
                printf(": can't map registers\n");
                return;
        }

        ptable = bus_space_vaddr(sc->sc_iot, sc->sc_ioh) +
            sc->sc_aux_size - PAGE_SIZE;
        if (ptable->magic != QCSMEM_PTABLE_MAGIC ||
            ptable->version != QCSMEM_PTABLE_VERSION) {
                printf(": unsupported ptable 0x%x/0x%x\n",
                    ptable->magic, ptable->version);
                bus_space_unmap(sc->sc_iot, sc->sc_ioh, sc->sc_aux_size);
                return;
        }

        header = bus_space_vaddr(sc->sc_iot, sc->sc_ioh);
        version = header->version[QCSMEM_HEADER_VERSION_MASTER_SBL_IDX] >> 16;
        if (version != QCSMEM_HEADER_VERSION_GLOBAL_PART) {
                printf(": unsupported header 0x%x\n", version);
                return;
        }

        for (i = 0; i < ptable->num_entries; i++) {
                pte = &ptable->entry[i];
                if (!pte->offset || !pte->size)
                        continue;
                if (pte->host[0] == QCSMEM_GLOBAL_HOST &&
                    pte->host[1] == QCSMEM_GLOBAL_HOST)
                        part = &sc->sc_global_partition;
                else if (pte->host[0] == QCSMEM_LOCAL_HOST &&
                    pte->host[1] < QCSMEM_HOST_COUNT)
                        part = &sc->sc_partitions[pte->host[1]];
                else if (pte->host[1] == QCSMEM_LOCAL_HOST &&
                    pte->host[0] < QCSMEM_HOST_COUNT)
                        part = &sc->sc_partitions[pte->host[0]];
                else
                        continue;
                if (part->phdr != NULL)
                        continue;
                phdr = bus_space_vaddr(sc->sc_iot, sc->sc_ioh) +
                    pte->offset;
                if (phdr->magic != QCSMEM_PART_HDR_MAGIC) {
                        printf(": unsupported partition 0x%x\n",
                            phdr->magic);
                        return;
                }
                if (pte->host[0] != phdr->host[0] ||
                    pte->host[1] != phdr->host[1]) {
                        printf(": bad hosts 0x%x/0x%x+0x%x/0x%x\n",
                            pte->host[0], phdr->host[0],
                            pte->host[1], phdr->host[1]);
                        return;
                }
                if (pte->size != phdr->size) {
                        printf(": bad size 0x%x/0x%x\n",
                            pte->size, phdr->size);
                        return;
                }
                if (phdr->offset_free_uncached > phdr->size) {
                        printf(": bad size 0x%x > 0x%x\n",
                            phdr->offset_free_uncached, phdr->size);
                        return;
                }
                part->phdr = phdr;
                part->size = pte->size;
                part->cacheline = pte->cacheline;
        }
        if (sc->sc_global_partition.phdr == NULL) {
                printf(": could not find global partition\n");
                return;
        }

        sc->sc_item_count = QCSMEM_ITEM_COUNT;
        info = (struct qcsmem_info *)&ptable->entry[ptable->num_entries];
        if (info->magic == QCSMEM_INFO_MAGIC)
                sc->sc_item_count = info->num_items;

        printf("\n");

        qcsmem_sc = sc;
}

int
qcsmem_alloc_private(struct qcsmem_softc *sc, struct qcsmem_partition *part,
    int item, int size)
{
        struct qcsmem_private_entry *entry, *last;
        struct qcsmem_partition_header *phdr = part->phdr;

        entry = (void *)&phdr[1];
        last = (void *)phdr + phdr->offset_free_uncached;

        if ((void *)last > (void *)phdr + part->size)
                return EINVAL;

        while (entry < last) {
                if (entry->canary != QCSMEM_PRIV_ENTRY_CANARY) {
                        printf("%s: invalid canary\n", sc->sc_dev.dv_xname);
                        return EINVAL;
                }

                if (entry->item == item)
                        return 0;

                entry = (void *)&entry[1] + entry->padding_hdr +
                    entry->size;
        }

        if ((void *)entry > (void *)phdr + part->size)
                return EINVAL;

        if ((void *)&entry[1] + roundup(size, 8) >
            (void *)phdr + phdr->offset_free_cached)
                return EINVAL;

        entry->canary = QCSMEM_PRIV_ENTRY_CANARY;
        entry->item = item;
        entry->size = roundup(size, 8);
        entry->padding_data = entry->size - size;
        entry->padding_hdr = 0;
        membar_producer();

        phdr->offset_free_uncached += sizeof(*entry) + entry->size;

        return 0;
}

int
qcsmem_alloc_global(struct qcsmem_softc *sc, int item, int size)
{
        struct qcsmem_header *header;
        struct qcsmem_global_entry *entry;

        header = bus_space_vaddr(sc->sc_iot, sc->sc_ioh);
        entry = &header->toc[item];
        if (entry->allocated)
                return 0;

        size = roundup(size, 8);
        if (size > header->available)
                return EINVAL;

        entry->offset = header->free_offset;
        entry->size = size;
        membar_producer();
        entry->allocated = 1;

        header->free_offset += size;
        header->available -= size;

        return 0;
}

int
qcsmem_alloc(int host, int item, int size)
{
        struct qcsmem_softc *sc = qcsmem_sc;
        struct qcsmem_partition *part;
        int ret;

        if (sc == NULL)
                return ENXIO;

        if (item < QCSMEM_ITEM_FIXED)
                return EPERM;

        if (item >= sc->sc_item_count)
                return ENXIO;

        ret = hwlock_lock_idx_timeout(sc->sc_node, 0, 1000);
        if (ret)
                return ret;

        if (host < QCSMEM_HOST_COUNT &&
            sc->sc_partitions[host].phdr != NULL) {
                part = &sc->sc_partitions[host];
                ret = qcsmem_alloc_private(sc, part, item, size);
        } else if (sc->sc_global_partition.phdr != NULL) {
                part = &sc->sc_global_partition;
                ret = qcsmem_alloc_private(sc, part, item, size);
        } else {
                ret = qcsmem_alloc_global(sc, item, size);
        }

        hwlock_unlock_idx(sc->sc_node, 0);
        return ret;
}

void *
qcsmem_get_private(struct qcsmem_softc *sc, struct qcsmem_partition *part,
    int item, int *size)
{
        struct qcsmem_private_entry *entry, *last;
        struct qcsmem_partition_header *phdr = part->phdr;

        entry = (void *)&phdr[1];
        last = (void *)phdr + phdr->offset_free_uncached;

        while (entry < last) {
                if (entry->canary != QCSMEM_PRIV_ENTRY_CANARY) {
                        printf("%s: invalid canary\n", sc->sc_dev.dv_xname);
                        return NULL;
                }

                if (entry->item == item) {
                        if (size != NULL) {
                                if (entry->size > part->size ||
                                    entry->padding_data > entry->size)
                                        return NULL;
                                *size = entry->size - entry->padding_data;
                        }

                        return (void *)&entry[1] + entry->padding_hdr;
                }

                entry = (void *)&entry[1] + entry->padding_hdr +
                    entry->size;
        }

        if ((void *)entry > (void *)phdr + part->size)
                return NULL;

        entry = (void *)phdr + phdr->size -
            roundup(sizeof(*entry), part->cacheline);
        last = (void *)phdr + phdr->offset_free_cached;

        if ((void *)entry < (void *)phdr ||
            (void *)last > (void *)phdr + part->size)
                return NULL;

        while (entry > last) {
                if (entry->canary != QCSMEM_PRIV_ENTRY_CANARY) {
                        printf("%s: invalid canary\n", sc->sc_dev.dv_xname);
                        return NULL;
                }

                if (entry->item == item) {
                        if (size != NULL) {
                                if (entry->size > part->size ||
                                    entry->padding_data > entry->size)
                                        return NULL;
                                *size = entry->size - entry->padding_data;
                        }

                        return (void *)entry - entry->size;
                }

                entry = (void *)entry - entry->size -
                    roundup(sizeof(*entry), part->cacheline);
        }

        if ((void *)entry < (void *)phdr)
                return NULL;

        return NULL;
}

void *
qcsmem_get_global(struct qcsmem_softc *sc, int item, int *size)
{
        struct qcsmem_header *header;
        struct qcsmem_global_entry *entry;
        uint32_t aux_base;

        header = bus_space_vaddr(sc->sc_iot, sc->sc_ioh);
        entry = &header->toc[item];
        if (!entry->allocated)
                return NULL;

        aux_base = entry->aux_base & QCSMEM_GLOBAL_ENTRY_AUX_BASE_MASK;
        if (aux_base != 0 && aux_base != sc->sc_aux_base)
                return NULL;

        if (entry->size + entry->offset > sc->sc_aux_size)
                return NULL;

        if (size != NULL)
                *size = entry->size;

        return bus_space_vaddr(sc->sc_iot, sc->sc_ioh) + entry->offset;
}

void *
qcsmem_get(int host, int item, int *size)
{
        struct qcsmem_softc *sc = qcsmem_sc;
        struct qcsmem_partition *part;
        void *p = NULL;
        int ret;

        if (sc == NULL)
                return NULL;

        if (item >= sc->sc_item_count)
                return NULL;

        ret = hwlock_lock_idx_timeout(sc->sc_node, 0, 1000);
        if (ret)
                return NULL;

        if (host < QCSMEM_HOST_COUNT &&
            sc->sc_partitions[host].phdr != NULL) {
                part = &sc->sc_partitions[host];
                p = qcsmem_get_private(sc, part, item, size);
        } else if (sc->sc_global_partition.phdr != NULL) {
                part = &sc->sc_global_partition;
                p = qcsmem_get_private(sc, part, item, size);
        } else {
                p = qcsmem_get_global(sc, item, size);
        }

        hwlock_unlock_idx(sc->sc_node, 0);
        return p;
}