// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2011-2018, The Linux Foundation. All rights reserved.
// Copyright (c) 2018, Linaro Limited

#include <linux/completion.h>
#include <linux/device.h>
#include <linux/dma-buf.h>
#include <linux/dma-mapping.h>
#include <linux/dma-resv.h>
#include <linux/idr.h>
#include <linux/list.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/sort.h>
#include <linux/of_platform.h>
#include <linux/rpmsg.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/firmware/qcom/qcom_scm.h>
#include <uapi/misc/fastrpc.h>
#include <linux/of_reserved_mem.h>
#include <linux/bits.h>

#define ADSP_DOMAIN_ID (0)
#define MDSP_DOMAIN_ID (1)
#define SDSP_DOMAIN_ID (2)
#define CDSP_DOMAIN_ID (3)
#define GDSP_DOMAIN_ID (4)
#define FASTRPC_MAX_SESSIONS    14
#define FASTRPC_MAX_VMIDS       16
#define FASTRPC_ALIGN           128
#define FASTRPC_MAX_FDLIST      16
#define FASTRPC_MAX_CRCLIST     64
#define FASTRPC_CTX_MAX (256)
#define FASTRPC_INIT_HANDLE     1
#define FASTRPC_DSP_UTILITIES_HANDLE    2
#define FASTRPC_CTXID_MASK (0xFF0)
#define INIT_FILELEN_MAX (2 * 1024 * 1024)
#define INIT_FILE_NAMELEN_MAX (128)
#define FASTRPC_DEVICE_NAME     "fastrpc"

/* Add memory to static PD pool, protection thru XPU */
#define ADSP_MMAP_HEAP_ADDR  4
/* MAP static DMA buffer on DSP User PD */
#define ADSP_MMAP_DMA_BUFFER  6
/* Add memory to static PD pool protection thru hypervisor */
#define ADSP_MMAP_REMOTE_HEAP_ADDR  8
/* Add memory to userPD pool, for user heap */
#define ADSP_MMAP_ADD_PAGES 0x1000
/* Add memory to userPD pool, for LLC heap */
#define ADSP_MMAP_ADD_PAGES_LLC 0x3000,

#define DSP_UNSUPPORTED_API (0x80000414)
/* MAX NUMBER of DSP ATTRIBUTES SUPPORTED */
#define FASTRPC_MAX_DSP_ATTRIBUTES (256)
#define FASTRPC_MAX_DSP_ATTRIBUTES_LEN (sizeof(u32) * FASTRPC_MAX_DSP_ATTRIBUTES)

/* Retrives number of input buffers from the scalars parameter */
#define REMOTE_SCALARS_INBUFS(sc)       (((sc) >> 16) & 0x0ff)

/* Retrives number of output buffers from the scalars parameter */
#define REMOTE_SCALARS_OUTBUFS(sc)      (((sc) >> 8) & 0x0ff)

/* Retrives number of input handles from the scalars parameter */
#define REMOTE_SCALARS_INHANDLES(sc)    (((sc) >> 4) & 0x0f)

/* Retrives number of output handles from the scalars parameter */
#define REMOTE_SCALARS_OUTHANDLES(sc)   ((sc) & 0x0f)

#define REMOTE_SCALARS_LENGTH(sc)       (REMOTE_SCALARS_INBUFS(sc) +   \
                                         REMOTE_SCALARS_OUTBUFS(sc) +  \
                                         REMOTE_SCALARS_INHANDLES(sc)+ \
                                         REMOTE_SCALARS_OUTHANDLES(sc))
#define FASTRPC_BUILD_SCALARS(attr, method, in, out, oin, oout)  \
                                (((attr & 0x07) << 29) |                \
                                ((method & 0x1f) << 24) |       \
                                ((in & 0xff) << 16) |           \
                                ((out & 0xff) <<  8) |          \
                                ((oin & 0x0f) <<  4) |          \
                                (oout & 0x0f))

#define FASTRPC_SCALARS(method, in, out) \
                FASTRPC_BUILD_SCALARS(0, method, in, out, 0, 0)

#define FASTRPC_CREATE_PROCESS_NARGS    6
#define FASTRPC_CREATE_STATIC_PROCESS_NARGS     3
/* Remote Method id table */
#define FASTRPC_RMID_INIT_ATTACH        0
#define FASTRPC_RMID_INIT_RELEASE       1
#define FASTRPC_RMID_INIT_MMAP          4
#define FASTRPC_RMID_INIT_MUNMAP        5
#define FASTRPC_RMID_INIT_CREATE        6
#define FASTRPC_RMID_INIT_CREATE_ATTR   7
#define FASTRPC_RMID_INIT_CREATE_STATIC 8
#define FASTRPC_RMID_INIT_MEM_MAP      10
#define FASTRPC_RMID_INIT_MEM_UNMAP    11

/* Protection Domain(PD) ids */
#define ROOT_PD         (0)
#define USER_PD         (1)
#define SENSORS_PD      (2)

#define miscdev_to_fdevice(d) container_of(d, struct fastrpc_device, miscdev)

struct fastrpc_phy_page {
        dma_addr_t addr;        /* dma address */
        u64 size;               /* size of contiguous region */
};

struct fastrpc_invoke_buf {
        u32 num;                /* number of contiguous regions */
        u32 pgidx;              /* index to start of contiguous region */
};

struct fastrpc_remote_dmahandle {
        s32 fd;         /* dma handle fd */
        u32 offset;     /* dma handle offset */
        u32 len;        /* dma handle length */
};

struct fastrpc_remote_buf {
        u64 pv;         /* buffer pointer */
        u64 len;        /* length of buffer */
};

union fastrpc_remote_arg {
        struct fastrpc_remote_buf buf;
        struct fastrpc_remote_dmahandle dma;
};

struct fastrpc_mmap_rsp_msg {
        u64 vaddr;
};

struct fastrpc_mmap_req_msg {
        s32 client_id;
        u32 flags;
        u64 vaddr;
        s32 num;
};

struct fastrpc_mem_map_req_msg {
        s32 client_id;
        s32 fd;
        s32 offset;
        u32 flags;
        u64 vaddrin;
        s32 num;
        s32 data_len;
};

struct fastrpc_munmap_req_msg {
        s32 client_id;
        u64 vaddr;
        u64 size;
};

struct fastrpc_mem_unmap_req_msg {
        s32 client_id;
        s32 fd;
        u64 vaddrin;
        u64 len;
};

struct fastrpc_msg {
        int client_id;          /* process client id */
        int tid;                /* thread id */
        u64 ctx;                /* invoke caller context */
        u32 handle;     /* handle to invoke */
        u32 sc;         /* scalars structure describing the data */
        dma_addr_t addr;        /* dma address */
        u64 size;               /* size of contiguous region */
};

struct fastrpc_invoke_rsp {
        u64 ctx;                /* invoke caller context */
        int retval;             /* invoke return value */
};

struct fastrpc_buf_overlap {
        u64 start;
        u64 end;
        int raix;
        u64 mstart;
        u64 mend;
        u64 offset;
};

struct fastrpc_buf {
        struct fastrpc_user *fl;
        struct dma_buf *dmabuf;
        struct device *dev;
        void *virt;
        dma_addr_t dma_addr;
        u64 size;
        /* Lock for dma buf attachments */
        struct mutex lock;
        struct list_head attachments;
        /* mmap support */
        struct list_head node; /* list of user requested mmaps */
        uintptr_t raddr;
};

struct fastrpc_dma_buf_attachment {
        struct device *dev;
        struct sg_table sgt;
        struct list_head node;
};

struct fastrpc_map {
        struct list_head node;
        struct fastrpc_user *fl;
        int fd;
        struct dma_buf *buf;
        struct sg_table *table;
        struct dma_buf_attachment *attach;
        dma_addr_t dma_addr;
        u64 size;
        void *va;
        u64 len;
        u64 raddr;
        u32 attr;
        struct kref refcount;
};

struct fastrpc_invoke_ctx {
        int nscalars;
        int nbufs;
        int retval;
        int pid;
        int client_id;
        u32 sc;
        u32 *crc;
        u64 ctxid;
        u64 msg_sz;
        struct kref refcount;
        struct list_head node; /* list of ctxs */
        struct completion work;
        struct work_struct put_work;
        struct fastrpc_msg msg;
        struct fastrpc_user *fl;
        union fastrpc_remote_arg *rpra;
        struct fastrpc_map **maps;
        struct fastrpc_buf *buf;
        struct fastrpc_invoke_args *args;
        struct fastrpc_buf_overlap *olaps;
        struct fastrpc_channel_ctx *cctx;
};

struct fastrpc_session_ctx {
        struct device *dev;
        int sid;
        bool used;
        bool valid;
};

struct fastrpc_soc_data {
        u32 sid_pos;
        u32 dma_addr_bits_cdsp;
        u32 dma_addr_bits_default;
};

struct fastrpc_channel_ctx {
        int domain_id;
        int sesscount;
        int vmcount;
        struct qcom_scm_vmperm vmperms[FASTRPC_MAX_VMIDS];
        struct rpmsg_device *rpdev;
        struct fastrpc_session_ctx session[FASTRPC_MAX_SESSIONS];
        spinlock_t lock;
        struct idr ctx_idr;
        struct list_head users;
        struct kref refcount;
        /* Flag if dsp attributes are cached */
        bool valid_attributes;
        u32 dsp_attributes[FASTRPC_MAX_DSP_ATTRIBUTES];
        struct fastrpc_device *secure_fdevice;
        struct fastrpc_device *fdevice;
        struct fastrpc_buf *remote_heap;
        struct list_head invoke_interrupted_mmaps;
        bool secure;
        bool unsigned_support;
        u64 dma_mask;
        const struct fastrpc_soc_data *soc_data;
};

struct fastrpc_device {
        struct fastrpc_channel_ctx *cctx;
        struct miscdevice miscdev;
        bool secure;
};

struct fastrpc_user {
        struct list_head user;
        struct list_head maps;
        struct list_head pending;
        struct list_head mmaps;

        struct fastrpc_channel_ctx *cctx;
        struct fastrpc_session_ctx *sctx;
        struct fastrpc_buf *init_mem;

        int client_id;
        int pd;
        bool is_secure_dev;
        /* Lock for lists */
        spinlock_t lock;
        /* lock for allocations */
        struct mutex mutex;
};

/* Extract SMMU PA from consolidated IOVA */
static inline dma_addr_t fastrpc_ipa_to_dma_addr(struct fastrpc_channel_ctx *cctx, dma_addr_t iova)
{
        if (!cctx->soc_data->sid_pos)
                return 0;
        return iova & GENMASK_ULL(cctx->soc_data->sid_pos - 1, 0);
}

/*
 * Prepare the consolidated iova to send to DSP by prepending the SID
 * to smmu PA at the appropriate position
 */
static inline u64 fastrpc_sid_offset(struct fastrpc_channel_ctx *cctx,
                                     struct fastrpc_session_ctx *sctx)
{
        return (u64)sctx->sid << cctx->soc_data->sid_pos;
}

static void fastrpc_free_map(struct kref *ref)
{
        struct fastrpc_map *map;

        map = container_of(ref, struct fastrpc_map, refcount);

        if (map->table) {
                if (map->attr & FASTRPC_ATTR_SECUREMAP) {
                        struct qcom_scm_vmperm perm;
                        int vmid = map->fl->cctx->vmperms[0].vmid;
                        u64 src_perms = BIT(QCOM_SCM_VMID_HLOS) | BIT(vmid);
                        int err = 0;

                        perm.vmid = QCOM_SCM_VMID_HLOS;
                        perm.perm = QCOM_SCM_PERM_RWX;
                        err = qcom_scm_assign_mem(map->dma_addr, map->len,
                                &src_perms, &perm, 1);
                        if (err) {
                                dev_err(map->fl->sctx->dev,
                                        "Failed to assign memory dma_addr %pad size 0x%llx err %d\n",
                                        &map->dma_addr, map->len, err);
                                return;
                        }
                }
                dma_buf_unmap_attachment_unlocked(map->attach, map->table,
                                                  DMA_BIDIRECTIONAL);
                dma_buf_detach(map->buf, map->attach);
                dma_buf_put(map->buf);
        }

        if (map->fl) {
                spin_lock(&map->fl->lock);
                list_del(&map->node);
                spin_unlock(&map->fl->lock);
                map->fl = NULL;
        }

        kfree(map);
}

static void fastrpc_map_put(struct fastrpc_map *map)
{
        if (map)
                kref_put(&map->refcount, fastrpc_free_map);
}

static int fastrpc_map_get(struct fastrpc_map *map)
{
        if (!map)
                return -ENOENT;

        return kref_get_unless_zero(&map->refcount) ? 0 : -ENOENT;
}


static int fastrpc_map_lookup(struct fastrpc_user *fl, int fd,
                            struct fastrpc_map **ppmap)
{
        struct fastrpc_map *map = NULL;
        struct dma_buf *buf;
        int ret = -ENOENT;

        buf = dma_buf_get(fd);
        if (IS_ERR(buf))
                return PTR_ERR(buf);

        spin_lock(&fl->lock);
        list_for_each_entry(map, &fl->maps, node) {
                if (map->fd != fd || map->buf != buf)
                        continue;

                *ppmap = map;
                ret = 0;
                break;
        }
        spin_unlock(&fl->lock);

        dma_buf_put(buf);

        return ret;
}

static void fastrpc_buf_free(struct fastrpc_buf *buf)
{
        dma_free_coherent(buf->dev, buf->size, buf->virt,
                          fastrpc_ipa_to_dma_addr(buf->fl->cctx, buf->dma_addr));
        kfree(buf);
}

static int __fastrpc_buf_alloc(struct fastrpc_user *fl, struct device *dev,
                             u64 size, struct fastrpc_buf **obuf)
{
        struct fastrpc_buf *buf;

        buf = kzalloc_obj(*buf);
        if (!buf)
                return -ENOMEM;

        INIT_LIST_HEAD(&buf->attachments);
        INIT_LIST_HEAD(&buf->node);
        mutex_init(&buf->lock);

        buf->fl = fl;
        buf->virt = NULL;
        buf->dma_addr = 0;
        buf->size = size;
        buf->dev = dev;
        buf->raddr = 0;

        buf->virt = dma_alloc_coherent(dev, buf->size, &buf->dma_addr,
                                       GFP_KERNEL);
        if (!buf->virt) {
                mutex_destroy(&buf->lock);
                kfree(buf);
                return -ENOMEM;
        }

        *obuf = buf;

        return 0;
}

static int fastrpc_buf_alloc(struct fastrpc_user *fl, struct device *dev,
                             u64 size, struct fastrpc_buf **obuf)
{
        int ret;
        struct fastrpc_buf *buf;

        ret = __fastrpc_buf_alloc(fl, dev, size, obuf);
        if (ret)
                return ret;

        buf = *obuf;

        if (fl->sctx && fl->sctx->sid)
                buf->dma_addr += fastrpc_sid_offset(fl->cctx, fl->sctx);

        return 0;
}

static int fastrpc_remote_heap_alloc(struct fastrpc_user *fl, struct device *dev,
                                     u64 size, struct fastrpc_buf **obuf)
{
        struct device *rdev = &fl->cctx->rpdev->dev;

        return  __fastrpc_buf_alloc(fl, rdev, size, obuf);
}

static void fastrpc_channel_ctx_free(struct kref *ref)
{
        struct fastrpc_channel_ctx *cctx;

        cctx = container_of(ref, struct fastrpc_channel_ctx, refcount);

        kfree(cctx);
}

static void fastrpc_channel_ctx_get(struct fastrpc_channel_ctx *cctx)
{
        kref_get(&cctx->refcount);
}

static void fastrpc_channel_ctx_put(struct fastrpc_channel_ctx *cctx)
{
        kref_put(&cctx->refcount, fastrpc_channel_ctx_free);
}

static void fastrpc_context_free(struct kref *ref)
{
        struct fastrpc_invoke_ctx *ctx;
        struct fastrpc_channel_ctx *cctx;
        unsigned long flags;
        int i;

        ctx = container_of(ref, struct fastrpc_invoke_ctx, refcount);
        cctx = ctx->cctx;

        for (i = 0; i < ctx->nbufs; i++)
                fastrpc_map_put(ctx->maps[i]);

        if (ctx->buf)
                fastrpc_buf_free(ctx->buf);

        spin_lock_irqsave(&cctx->lock, flags);
        idr_remove(&cctx->ctx_idr, ctx->ctxid >> 4);
        spin_unlock_irqrestore(&cctx->lock, flags);

        kfree(ctx->maps);
        kfree(ctx->olaps);
        kfree(ctx);

        fastrpc_channel_ctx_put(cctx);
}

static void fastrpc_context_get(struct fastrpc_invoke_ctx *ctx)
{
        kref_get(&ctx->refcount);
}

static void fastrpc_context_put(struct fastrpc_invoke_ctx *ctx)
{
        kref_put(&ctx->refcount, fastrpc_context_free);
}

static void fastrpc_context_put_wq(struct work_struct *work)
{
        struct fastrpc_invoke_ctx *ctx =
                        container_of(work, struct fastrpc_invoke_ctx, put_work);

        fastrpc_context_put(ctx);
}

#define CMP(aa, bb) ((aa) == (bb) ? 0 : (aa) < (bb) ? -1 : 1)
static int olaps_cmp(const void *a, const void *b)
{
        struct fastrpc_buf_overlap *pa = (struct fastrpc_buf_overlap *)a;
        struct fastrpc_buf_overlap *pb = (struct fastrpc_buf_overlap *)b;
        /* sort with lowest starting buffer first */
        int st = CMP(pa->start, pb->start);
        /* sort with highest ending buffer first */
        int ed = CMP(pb->end, pa->end);

        return st == 0 ? ed : st;
}

static void fastrpc_get_buff_overlaps(struct fastrpc_invoke_ctx *ctx)
{
        u64 max_end = 0;
        int i;

        for (i = 0; i < ctx->nbufs; ++i) {
                ctx->olaps[i].start = ctx->args[i].ptr;
                ctx->olaps[i].end = ctx->olaps[i].start + ctx->args[i].length;
                ctx->olaps[i].raix = i;
        }

        sort(ctx->olaps, ctx->nbufs, sizeof(*ctx->olaps), olaps_cmp, NULL);

        for (i = 0; i < ctx->nbufs; ++i) {
                /* Falling inside previous range */
                if (ctx->olaps[i].start < max_end) {
                        ctx->olaps[i].mstart = max_end;
                        ctx->olaps[i].mend = ctx->olaps[i].end;
                        ctx->olaps[i].offset = max_end - ctx->olaps[i].start;

                        if (ctx->olaps[i].end > max_end) {
                                max_end = ctx->olaps[i].end;
                        } else {
                                ctx->olaps[i].mend = 0;
                                ctx->olaps[i].mstart = 0;
                        }

                } else  {
                        ctx->olaps[i].mend = ctx->olaps[i].end;
                        ctx->olaps[i].mstart = ctx->olaps[i].start;
                        ctx->olaps[i].offset = 0;
                        max_end = ctx->olaps[i].end;
                }
        }
}

static struct fastrpc_invoke_ctx *fastrpc_context_alloc(
                        struct fastrpc_user *user, u32 kernel, u32 sc,
                        struct fastrpc_invoke_args *args)
{
        struct fastrpc_channel_ctx *cctx = user->cctx;
        struct fastrpc_invoke_ctx *ctx = NULL;
        unsigned long flags;
        int ret;

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

        INIT_LIST_HEAD(&ctx->node);
        ctx->fl = user;
        ctx->nscalars = REMOTE_SCALARS_LENGTH(sc);
        ctx->nbufs = REMOTE_SCALARS_INBUFS(sc) +
                     REMOTE_SCALARS_OUTBUFS(sc);

        if (ctx->nscalars) {
                ctx->maps = kzalloc_objs(*ctx->maps, ctx->nscalars);
                if (!ctx->maps) {
                        kfree(ctx);
                        return ERR_PTR(-ENOMEM);
                }
                ctx->olaps = kzalloc_objs(*ctx->olaps, ctx->nscalars);
                if (!ctx->olaps) {
                        kfree(ctx->maps);
                        kfree(ctx);
                        return ERR_PTR(-ENOMEM);
                }
                ctx->args = args;
                fastrpc_get_buff_overlaps(ctx);
        }

        /* Released in fastrpc_context_put() */
        fastrpc_channel_ctx_get(cctx);

        ctx->sc = sc;
        ctx->retval = -1;
        ctx->pid = current->pid;
        ctx->client_id = user->client_id;
        ctx->cctx = cctx;
        init_completion(&ctx->work);
        INIT_WORK(&ctx->put_work, fastrpc_context_put_wq);

        spin_lock(&user->lock);
        list_add_tail(&ctx->node, &user->pending);
        spin_unlock(&user->lock);

        spin_lock_irqsave(&cctx->lock, flags);
        ret = idr_alloc_cyclic(&cctx->ctx_idr, ctx, 1,
                               FASTRPC_CTX_MAX, GFP_ATOMIC);
        if (ret < 0) {
                spin_unlock_irqrestore(&cctx->lock, flags);
                goto err_idr;
        }
        ctx->ctxid = ret << 4;
        spin_unlock_irqrestore(&cctx->lock, flags);

        kref_init(&ctx->refcount);

        return ctx;
err_idr:
        spin_lock(&user->lock);
        list_del(&ctx->node);
        spin_unlock(&user->lock);
        fastrpc_channel_ctx_put(cctx);
        kfree(ctx->maps);
        kfree(ctx->olaps);
        kfree(ctx);

        return ERR_PTR(ret);
}

static struct sg_table *
fastrpc_map_dma_buf(struct dma_buf_attachment *attachment,
                    enum dma_data_direction dir)
{
        struct fastrpc_dma_buf_attachment *a = attachment->priv;
        struct sg_table *table;
        int ret;

        table = &a->sgt;

        ret = dma_map_sgtable(attachment->dev, table, dir, 0);
        if (ret)
                table = ERR_PTR(ret);
        return table;
}

static void fastrpc_unmap_dma_buf(struct dma_buf_attachment *attach,
                                  struct sg_table *table,
                                  enum dma_data_direction dir)
{
        dma_unmap_sgtable(attach->dev, table, dir, 0);
}

static void fastrpc_release(struct dma_buf *dmabuf)
{
        struct fastrpc_buf *buffer = dmabuf->priv;

        fastrpc_buf_free(buffer);
}

static int fastrpc_dma_buf_attach(struct dma_buf *dmabuf,
                                  struct dma_buf_attachment *attachment)
{
        struct fastrpc_dma_buf_attachment *a;
        struct fastrpc_buf *buffer = dmabuf->priv;
        int ret;

        a = kzalloc_obj(*a);
        if (!a)
                return -ENOMEM;

        ret = dma_get_sgtable(buffer->dev, &a->sgt, buffer->virt,
                              fastrpc_ipa_to_dma_addr(buffer->fl->cctx, buffer->dma_addr),
                              buffer->size);
        if (ret < 0) {
                dev_err(buffer->dev, "failed to get scatterlist from DMA API\n");
                kfree(a);
                return -EINVAL;
        }

        a->dev = attachment->dev;
        INIT_LIST_HEAD(&a->node);
        attachment->priv = a;

        mutex_lock(&buffer->lock);
        list_add(&a->node, &buffer->attachments);
        mutex_unlock(&buffer->lock);

        return 0;
}

static void fastrpc_dma_buf_detatch(struct dma_buf *dmabuf,
                                    struct dma_buf_attachment *attachment)
{
        struct fastrpc_dma_buf_attachment *a = attachment->priv;
        struct fastrpc_buf *buffer = dmabuf->priv;

        mutex_lock(&buffer->lock);
        list_del(&a->node);
        mutex_unlock(&buffer->lock);
        sg_free_table(&a->sgt);
        kfree(a);
}

static int fastrpc_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
{
        struct fastrpc_buf *buf = dmabuf->priv;

        iosys_map_set_vaddr(map, buf->virt);

        return 0;
}

static int fastrpc_mmap(struct dma_buf *dmabuf,
                        struct vm_area_struct *vma)
{
        struct fastrpc_buf *buf = dmabuf->priv;
        size_t size = vma->vm_end - vma->vm_start;

        dma_resv_assert_held(dmabuf->resv);

        return dma_mmap_coherent(buf->dev, vma, buf->virt,
                                 fastrpc_ipa_to_dma_addr(buf->fl->cctx, buf->dma_addr), size);
}

static const struct dma_buf_ops fastrpc_dma_buf_ops = {
        .attach = fastrpc_dma_buf_attach,
        .detach = fastrpc_dma_buf_detatch,
        .map_dma_buf = fastrpc_map_dma_buf,
        .unmap_dma_buf = fastrpc_unmap_dma_buf,
        .mmap = fastrpc_mmap,
        .vmap = fastrpc_vmap,
        .release = fastrpc_release,
};

static dma_addr_t fastrpc_compute_dma_addr(struct fastrpc_user *fl, dma_addr_t sg_dma_addr)
{
        return sg_dma_addr + fastrpc_sid_offset(fl->cctx, fl->sctx);
}

static int fastrpc_map_attach(struct fastrpc_user *fl, int fd,
                              u64 len, u32 attr, struct fastrpc_map **ppmap)
{
        struct fastrpc_session_ctx *sess = fl->sctx;
        struct fastrpc_map *map = NULL;
        struct sg_table *table;
        struct scatterlist *sgl = NULL;
        int err = 0, sgl_index = 0;

        map = kzalloc_obj(*map);
        if (!map)
                return -ENOMEM;

        INIT_LIST_HEAD(&map->node);
        kref_init(&map->refcount);

        map->fl = fl;
        map->fd = fd;
        map->buf = dma_buf_get(fd);
        if (IS_ERR(map->buf)) {
                err = PTR_ERR(map->buf);
                goto get_err;
        }

        map->attach = dma_buf_attach(map->buf, sess->dev);
        if (IS_ERR(map->attach)) {
                dev_err(sess->dev, "Failed to attach dmabuf\n");
                err = PTR_ERR(map->attach);
                goto attach_err;
        }

        table = dma_buf_map_attachment_unlocked(map->attach, DMA_BIDIRECTIONAL);
        if (IS_ERR(table)) {
                err = PTR_ERR(table);
                goto map_err;
        }
        map->table = table;

        if (attr & FASTRPC_ATTR_SECUREMAP)
                map->dma_addr = sg_phys(map->table->sgl);
        else
                map->dma_addr = fastrpc_compute_dma_addr(fl, sg_dma_address(map->table->sgl));
        for_each_sg(map->table->sgl, sgl, map->table->nents,
                sgl_index)
                map->size += sg_dma_len(sgl);
        if (len > map->size) {
                dev_dbg(sess->dev, "Bad size passed len 0x%llx map size 0x%llx\n",
                                len, map->size);
                err = -EINVAL;
                goto map_err;
        }
        map->va = sg_virt(map->table->sgl);
        map->len = len;

        if (attr & FASTRPC_ATTR_SECUREMAP) {
                /*
                 * If subsystem VMIDs are defined in DTSI, then do
                 * hyp_assign from HLOS to those VM(s)
                 */
                u64 src_perms = BIT(QCOM_SCM_VMID_HLOS);
                struct qcom_scm_vmperm dst_perms[2] = {0};

                dst_perms[0].vmid = QCOM_SCM_VMID_HLOS;
                dst_perms[0].perm = QCOM_SCM_PERM_RW;
                dst_perms[1].vmid = fl->cctx->vmperms[0].vmid;
                dst_perms[1].perm = QCOM_SCM_PERM_RWX;
                map->attr = attr;
                err = qcom_scm_assign_mem(map->dma_addr, (u64)map->len, &src_perms, dst_perms, 2);
                if (err) {
                        dev_err(sess->dev,
                                "Failed to assign memory with dma_addr %pad size 0x%llx err %d\n",
                                &map->dma_addr, map->len, err);
                        goto map_err;
                }
        }
        spin_lock(&fl->lock);
        list_add_tail(&map->node, &fl->maps);
        spin_unlock(&fl->lock);
        *ppmap = map;

        return 0;

map_err:
        dma_buf_detach(map->buf, map->attach);
attach_err:
        dma_buf_put(map->buf);
get_err:
        fastrpc_map_put(map);

        return err;
}

static int fastrpc_map_create(struct fastrpc_user *fl, int fd,
                              u64 len, u32 attr, struct fastrpc_map **ppmap)
{
        struct fastrpc_session_ctx *sess = fl->sctx;
        int err = 0;

        if (!fastrpc_map_lookup(fl, fd, ppmap)) {
                if (!fastrpc_map_get(*ppmap))
                        return 0;
                dev_dbg(sess->dev, "%s: Failed to get map fd=%d\n",
                        __func__, fd);
        }

        err = fastrpc_map_attach(fl, fd, len, attr, ppmap);

        return err;
}

/*
 * Fastrpc payload buffer with metadata looks like:
 *
 * >>>>>>  START of METADATA <<<<<<<<<
 * +---------------------------------+
 * |           Arguments             |
 * | type:(union fastrpc_remote_arg)|
 * |             (0 - N)             |
 * +---------------------------------+
 * |         Invoke Buffer list      |
 * | type:(struct fastrpc_invoke_buf)|
 * |           (0 - N)               |
 * +---------------------------------+
 * |         Page info list          |
 * | type:(struct fastrpc_phy_page)  |
 * |             (0 - N)             |
 * +---------------------------------+
 * |         Optional info           |
 * |(can be specific to SoC/Firmware)|
 * +---------------------------------+
 * >>>>>>>>  END of METADATA <<<<<<<<<
 * +---------------------------------+
 * |         Inline ARGS             |
 * |            (0-N)                |
 * +---------------------------------+
 */

static int fastrpc_get_meta_size(struct fastrpc_invoke_ctx *ctx)
{
        int size = 0;

        size = (sizeof(struct fastrpc_remote_buf) +
                sizeof(struct fastrpc_invoke_buf) +
                sizeof(struct fastrpc_phy_page)) * ctx->nscalars +
                sizeof(u64) * FASTRPC_MAX_FDLIST +
                sizeof(u32) * FASTRPC_MAX_CRCLIST;

        return size;
}

static u64 fastrpc_get_payload_size(struct fastrpc_invoke_ctx *ctx, int metalen)
{
        u64 size = 0;
        int oix;

        size = ALIGN(metalen, FASTRPC_ALIGN);
        for (oix = 0; oix < ctx->nbufs; oix++) {
                int i = ctx->olaps[oix].raix;

                if (ctx->args[i].fd == 0 || ctx->args[i].fd == -1) {

                        if (ctx->olaps[oix].offset == 0)
                                size = ALIGN(size, FASTRPC_ALIGN);

                        size += (ctx->olaps[oix].mend - ctx->olaps[oix].mstart);
                }
        }

        return size;
}

static int fastrpc_create_maps(struct fastrpc_invoke_ctx *ctx)
{
        struct device *dev = ctx->fl->sctx->dev;
        int i, err;

        for (i = 0; i < ctx->nscalars; ++i) {

                if (ctx->args[i].fd == 0 || ctx->args[i].fd == -1 ||
                    ctx->args[i].length == 0)
                        continue;

                if (i < ctx->nbufs)
                        err = fastrpc_map_create(ctx->fl, ctx->args[i].fd,
                                 ctx->args[i].length, ctx->args[i].attr, &ctx->maps[i]);
                else
                        err = fastrpc_map_attach(ctx->fl, ctx->args[i].fd,
                                 ctx->args[i].length, ctx->args[i].attr, &ctx->maps[i]);
                if (err) {
                        dev_err(dev, "Error Creating map %d\n", err);
                        return -EINVAL;
                }

        }
        return 0;
}

static struct fastrpc_invoke_buf *fastrpc_invoke_buf_start(union fastrpc_remote_arg *pra, int len)
{
        return (struct fastrpc_invoke_buf *)(&pra[len]);
}

static struct fastrpc_phy_page *fastrpc_phy_page_start(struct fastrpc_invoke_buf *buf, int len)
{
        return (struct fastrpc_phy_page *)(&buf[len]);
}

static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx)
{
        struct device *dev = ctx->fl->sctx->dev;
        union fastrpc_remote_arg *rpra;
        struct fastrpc_invoke_buf *list;
        struct fastrpc_phy_page *pages;
        int inbufs, i, oix, err = 0;
        u64 len, rlen, pkt_size;
        u64 pg_start, pg_end;
        uintptr_t args;
        int metalen;

        inbufs = REMOTE_SCALARS_INBUFS(ctx->sc);
        metalen = fastrpc_get_meta_size(ctx);
        pkt_size = fastrpc_get_payload_size(ctx, metalen);

        err = fastrpc_create_maps(ctx);
        if (err)
                return err;

        ctx->msg_sz = pkt_size;

        if (ctx->fl->sctx->sid)
                err = fastrpc_buf_alloc(ctx->fl, dev, pkt_size, &ctx->buf);
        else
                err = fastrpc_remote_heap_alloc(ctx->fl, dev, pkt_size, &ctx->buf);
        if (err)
                return err;

        memset(ctx->buf->virt, 0, pkt_size);
        rpra = ctx->buf->virt;
        list = fastrpc_invoke_buf_start(rpra, ctx->nscalars);
        pages = fastrpc_phy_page_start(list, ctx->nscalars);
        args = (uintptr_t)ctx->buf->virt + metalen;
        rlen = pkt_size - metalen;
        ctx->rpra = rpra;

        for (oix = 0; oix < ctx->nbufs; ++oix) {
                int mlen;

                i = ctx->olaps[oix].raix;
                len = ctx->args[i].length;

                rpra[i].buf.pv = 0;
                rpra[i].buf.len = len;
                list[i].num = len ? 1 : 0;
                list[i].pgidx = i;

                if (!len)
                        continue;

                if (ctx->maps[i]) {
                        struct vm_area_struct *vma = NULL;

                        rpra[i].buf.pv = (u64) ctx->args[i].ptr;
                        pages[i].addr = ctx->maps[i]->dma_addr;

                        mmap_read_lock(current->mm);
                        vma = find_vma(current->mm, ctx->args[i].ptr);
                        if (vma)
                                pages[i].addr += (ctx->args[i].ptr & PAGE_MASK) -
                                                 vma->vm_start;
                        mmap_read_unlock(current->mm);

                        pg_start = (ctx->args[i].ptr & PAGE_MASK) >> PAGE_SHIFT;
                        pg_end = ((ctx->args[i].ptr + len - 1) & PAGE_MASK) >>
                                  PAGE_SHIFT;
                        pages[i].size = (pg_end - pg_start + 1) * PAGE_SIZE;

                } else {

                        if (ctx->olaps[oix].offset == 0) {
                                rlen -= ALIGN(args, FASTRPC_ALIGN) - args;
                                args = ALIGN(args, FASTRPC_ALIGN);
                        }

                        mlen = ctx->olaps[oix].mend - ctx->olaps[oix].mstart;

                        if (rlen < mlen)
                                goto bail;

                        rpra[i].buf.pv = args - ctx->olaps[oix].offset;
                        pages[i].addr = ctx->buf->dma_addr -
                                        ctx->olaps[oix].offset +
                                        (pkt_size - rlen);
                        pages[i].addr = pages[i].addr & PAGE_MASK;

                        pg_start = (rpra[i].buf.pv & PAGE_MASK) >> PAGE_SHIFT;
                        pg_end = ((rpra[i].buf.pv + len - 1) & PAGE_MASK) >> PAGE_SHIFT;
                        pages[i].size = (pg_end - pg_start + 1) * PAGE_SIZE;
                        args = args + mlen;
                        rlen -= mlen;
                }

                if (i < inbufs && !ctx->maps[i]) {
                        void *dst = (void *)(uintptr_t)rpra[i].buf.pv;
                        void *src = (void *)(uintptr_t)ctx->args[i].ptr;

                        if (!kernel) {
                                if (copy_from_user(dst, (void __user *)src,
                                                   len)) {
                                        err = -EFAULT;
                                        goto bail;
                                }
                        } else {
                                memcpy(dst, src, len);
                        }
                }
        }

        for (i = ctx->nbufs; i < ctx->nscalars; ++i) {
                list[i].num = ctx->args[i].length ? 1 : 0;
                list[i].pgidx = i;
                if (ctx->maps[i]) {
                        pages[i].addr = ctx->maps[i]->dma_addr;
                        pages[i].size = ctx->maps[i]->size;
                }
                rpra[i].dma.fd = ctx->args[i].fd;
                rpra[i].dma.len = ctx->args[i].length;
                rpra[i].dma.offset = (u64) ctx->args[i].ptr;
        }

bail:
        if (err)
                dev_err(dev, "Error: get invoke args failed:%d\n", err);

        return err;
}

static int fastrpc_put_args(struct fastrpc_invoke_ctx *ctx,
                            u32 kernel)
{
        union fastrpc_remote_arg *rpra = ctx->rpra;
        struct fastrpc_user *fl = ctx->fl;
        struct fastrpc_map *mmap = NULL;
        struct fastrpc_invoke_buf *list;
        struct fastrpc_phy_page *pages;
        u64 *fdlist;
        int i, inbufs, outbufs, handles;
        int ret = 0;

        inbufs = REMOTE_SCALARS_INBUFS(ctx->sc);
        outbufs = REMOTE_SCALARS_OUTBUFS(ctx->sc);
        handles = REMOTE_SCALARS_INHANDLES(ctx->sc) + REMOTE_SCALARS_OUTHANDLES(ctx->sc);
        list = fastrpc_invoke_buf_start(rpra, ctx->nscalars);
        pages = fastrpc_phy_page_start(list, ctx->nscalars);
        fdlist = (uint64_t *)(pages + inbufs + outbufs + handles);

        for (i = inbufs; i < ctx->nbufs; ++i) {
                if (!ctx->maps[i]) {
                        void *src = (void *)(uintptr_t)rpra[i].buf.pv;
                        void *dst = (void *)(uintptr_t)ctx->args[i].ptr;
                        u64 len = rpra[i].buf.len;

                        if (!kernel) {
                                if (copy_to_user((void __user *)dst, src, len)) {
                                        ret = -EFAULT;
                                        goto cleanup_fdlist;
                                }
                        } else {
                                memcpy(dst, src, len);
                        }
                }
        }

cleanup_fdlist:
        /* Clean up fdlist which is updated by DSP */
        for (i = 0; i < FASTRPC_MAX_FDLIST; i++) {
                if (!fdlist[i])
                        break;
                if (!fastrpc_map_lookup(fl, (int)fdlist[i], &mmap))
                        fastrpc_map_put(mmap);
        }

        return ret;
}

static int fastrpc_invoke_send(struct fastrpc_session_ctx *sctx,
                               struct fastrpc_invoke_ctx *ctx,
                               u32 kernel, uint32_t handle)
{
        struct fastrpc_channel_ctx *cctx;
        struct fastrpc_user *fl = ctx->fl;
        struct fastrpc_msg *msg = &ctx->msg;
        int ret;

        cctx = fl->cctx;
        msg->client_id = fl->client_id;
        msg->tid = current->pid;

        if (kernel)
                msg->client_id = 0;

        msg->ctx = ctx->ctxid | fl->pd;
        msg->handle = handle;
        msg->sc = ctx->sc;
        msg->addr = ctx->buf ? ctx->buf->dma_addr : 0;
        msg->size = roundup(ctx->msg_sz, PAGE_SIZE);
        fastrpc_context_get(ctx);

        ret = rpmsg_send(cctx->rpdev->ept, (void *)msg, sizeof(*msg));

        if (ret)
                fastrpc_context_put(ctx);

        return ret;

}

static int fastrpc_internal_invoke(struct fastrpc_user *fl,  u32 kernel,
                                   u32 handle, u32 sc,
                                   struct fastrpc_invoke_args *args)
{
        struct fastrpc_invoke_ctx *ctx = NULL;
        struct fastrpc_buf *buf, *b;

        int err = 0;

        if (!fl->sctx)
                return -EINVAL;

        if (!fl->cctx->rpdev)
                return -EPIPE;

        if (handle == FASTRPC_INIT_HANDLE && !kernel) {
                dev_warn_ratelimited(fl->sctx->dev, "user app trying to send a kernel RPC message (%d)\n",  handle);
                return -EPERM;
        }

        ctx = fastrpc_context_alloc(fl, kernel, sc, args);
        if (IS_ERR(ctx))
                return PTR_ERR(ctx);

        err = fastrpc_get_args(kernel, ctx);
        if (err)
                goto bail;

        /* make sure that all CPU memory writes are seen by DSP */
        dma_wmb();
        /* Send invoke buffer to remote dsp */
        err = fastrpc_invoke_send(fl->sctx, ctx, kernel, handle);
        if (err)
                goto bail;

        if (kernel) {
                if (!wait_for_completion_timeout(&ctx->work, 10 * HZ))
                        err = -ETIMEDOUT;
        } else {
                err = wait_for_completion_interruptible(&ctx->work);
        }

        if (err)
                goto bail;

        /* make sure that all memory writes by DSP are seen by CPU */
        dma_rmb();
        /* populate all the output buffers with results */
        err = fastrpc_put_args(ctx, kernel);
        if (err)
                goto bail;

        /* Check the response from remote dsp */
        err = ctx->retval;
        if (err)
                goto bail;

bail:
        if (err != -ERESTARTSYS && err != -ETIMEDOUT) {
                /* We are done with this compute context */
                spin_lock(&fl->lock);
                list_del(&ctx->node);
                spin_unlock(&fl->lock);
                fastrpc_context_put(ctx);
        }

        if (err == -ERESTARTSYS) {
                list_for_each_entry_safe(buf, b, &fl->mmaps, node) {
                        list_del(&buf->node);
                        list_add_tail(&buf->node, &fl->cctx->invoke_interrupted_mmaps);
                }
        }

        if (err)
                dev_dbg(fl->sctx->dev, "Error: Invoke Failed %d\n", err);

        return err;
}

static bool is_session_rejected(struct fastrpc_user *fl, bool unsigned_pd_request)
{
        /* Check if the device node is non-secure and channel is secure*/
        if (!fl->is_secure_dev && fl->cctx->secure) {
                /*
                 * Allow untrusted applications to offload only to Unsigned PD when
                 * channel is configured as secure and block untrusted apps on channel
                 * that does not support unsigned PD offload
                 */
                if (!fl->cctx->unsigned_support || !unsigned_pd_request) {
                        dev_err(&fl->cctx->rpdev->dev, "Error: Untrusted application trying to offload to signed PD\n");
                        return true;
                }
        }

        return false;
}

static int fastrpc_init_create_static_process(struct fastrpc_user *fl,
                                              char __user *argp)
{
        struct fastrpc_init_create_static init;
        struct fastrpc_invoke_args *args;
        struct fastrpc_phy_page pages[1];
        char *name;
        int err;
        bool scm_done = false;
        struct {
                int client_id;
                u32 namelen;
                u32 pageslen;
        } inbuf;
        u32 sc;

        args = kzalloc_objs(*args, FASTRPC_CREATE_STATIC_PROCESS_NARGS);
        if (!args)
                return -ENOMEM;

        if (copy_from_user(&init, argp, sizeof(init))) {
                err = -EFAULT;
                goto err;
        }

        if (init.namelen > INIT_FILE_NAMELEN_MAX) {
                err = -EINVAL;
                goto err;
        }

        name = memdup_user(u64_to_user_ptr(init.name), init.namelen);
        if (IS_ERR(name)) {
                err = PTR_ERR(name);
                goto err;
        }

        if (!fl->cctx->remote_heap) {
                err = fastrpc_remote_heap_alloc(fl, fl->sctx->dev, init.memlen,
                                                &fl->cctx->remote_heap);
                if (err)
                        goto err_name;

                /* Map if we have any heap VMIDs associated with this ADSP Static Process. */
                if (fl->cctx->vmcount) {
                        u64 src_perms = BIT(QCOM_SCM_VMID_HLOS);

                        err = qcom_scm_assign_mem(fl->cctx->remote_heap->dma_addr,
                                                        (u64)fl->cctx->remote_heap->size,
                                                        &src_perms,
                                                        fl->cctx->vmperms, fl->cctx->vmcount);
                        if (err) {
                                dev_err(fl->sctx->dev,
                                        "Failed to assign memory with dma_addr %pad size 0x%llx err %d\n",
                                        &fl->cctx->remote_heap->dma_addr,
                                        fl->cctx->remote_heap->size, err);
                                goto err_map;
                        }
                        scm_done = true;
                }
        }

        inbuf.client_id = fl->client_id;
        inbuf.namelen = init.namelen;
        inbuf.pageslen = 0;
        fl->pd = USER_PD;

        args[0].ptr = (u64)(uintptr_t)&inbuf;
        args[0].length = sizeof(inbuf);
        args[0].fd = -1;

        args[1].ptr = (u64)(uintptr_t)name;
        args[1].length = inbuf.namelen;
        args[1].fd = -1;

        pages[0].addr = fl->cctx->remote_heap->dma_addr;
        pages[0].size = fl->cctx->remote_heap->size;

        args[2].ptr = (u64)(uintptr_t) pages;
        args[2].length = sizeof(*pages);
        args[2].fd = -1;

        sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_CREATE_STATIC, 3, 0);

        err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE,
                                      sc, args);
        if (err)
                goto err_invoke;

        kfree(args);
        kfree(name);

        return 0;
err_invoke:
        if (fl->cctx->vmcount && scm_done) {
                u64 src_perms = 0;
                struct qcom_scm_vmperm dst_perms;
                u32 i;

                for (i = 0; i < fl->cctx->vmcount; i++)
                        src_perms |= BIT(fl->cctx->vmperms[i].vmid);

                dst_perms.vmid = QCOM_SCM_VMID_HLOS;
                dst_perms.perm = QCOM_SCM_PERM_RWX;
                err = qcom_scm_assign_mem(fl->cctx->remote_heap->dma_addr,
                                                (u64)fl->cctx->remote_heap->size,
                                                &src_perms, &dst_perms, 1);
                if (err)
                        dev_err(fl->sctx->dev, "Failed to assign memory dma_addr %pad size 0x%llx err %d\n",
                                &fl->cctx->remote_heap->dma_addr, fl->cctx->remote_heap->size, err);
        }
err_map:
        fastrpc_buf_free(fl->cctx->remote_heap);
        fl->cctx->remote_heap = NULL;
err_name:
        kfree(name);
err:
        kfree(args);

        return err;
}

static int fastrpc_init_create_process(struct fastrpc_user *fl,
                                        char __user *argp)
{
        struct fastrpc_init_create init;
        struct fastrpc_invoke_args *args;
        struct fastrpc_phy_page pages[1];
        struct fastrpc_map *map = NULL;
        struct fastrpc_buf *imem = NULL;
        int memlen;
        int err;
        struct {
                int client_id;
                u32 namelen;
                u32 filelen;
                u32 pageslen;
                u32 attrs;
                u32 siglen;
        } inbuf;
        u32 sc;
        bool unsigned_module = false;

        args = kzalloc_objs(*args, FASTRPC_CREATE_PROCESS_NARGS);
        if (!args)
                return -ENOMEM;

        if (copy_from_user(&init, argp, sizeof(init))) {
                err = -EFAULT;
                goto err;
        }

        if (init.attrs & FASTRPC_MODE_UNSIGNED_MODULE)
                unsigned_module = true;

        if (is_session_rejected(fl, unsigned_module)) {
                err = -ECONNREFUSED;
                goto err;
        }

        if (init.filelen > INIT_FILELEN_MAX) {
                err = -EINVAL;
                goto err;
        }

        inbuf.client_id = fl->client_id;
        inbuf.namelen = strlen(current->comm) + 1;
        inbuf.filelen = init.filelen;
        inbuf.pageslen = 1;
        inbuf.attrs = init.attrs;
        inbuf.siglen = init.siglen;
        fl->pd = USER_PD;

        if (init.filelen && init.filefd) {
                err = fastrpc_map_create(fl, init.filefd, init.filelen, 0, &map);
                if (err)
                        goto err;
        }

        memlen = ALIGN(max(INIT_FILELEN_MAX, (int)init.filelen * 4),
                       1024 * 1024);
        err = fastrpc_buf_alloc(fl, fl->sctx->dev, memlen,
                                &imem);
        if (err)
                goto err_alloc;

        fl->init_mem = imem;
        args[0].ptr = (u64)(uintptr_t)&inbuf;
        args[0].length = sizeof(inbuf);
        args[0].fd = -1;

        args[1].ptr = (u64)(uintptr_t)current->comm;
        args[1].length = inbuf.namelen;
        args[1].fd = -1;

        args[2].ptr = (u64) init.file;
        args[2].length = inbuf.filelen;
        args[2].fd = init.filefd;

        pages[0].addr = imem->dma_addr;
        pages[0].size = imem->size;

        args[3].ptr = (u64)(uintptr_t) pages;
        args[3].length = 1 * sizeof(*pages);
        args[3].fd = -1;

        args[4].ptr = (u64)(uintptr_t)&inbuf.attrs;
        args[4].length = sizeof(inbuf.attrs);
        args[4].fd = -1;

        args[5].ptr = (u64)(uintptr_t) &inbuf.siglen;
        args[5].length = sizeof(inbuf.siglen);
        args[5].fd = -1;

        sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_CREATE, 4, 0);
        if (init.attrs)
                sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_CREATE_ATTR, 4, 0);

        err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE,
                                      sc, args);
        if (err)
                goto err_invoke;

        kfree(args);

        return 0;

err_invoke:
        fl->init_mem = NULL;
        fastrpc_buf_free(imem);
err_alloc:
        fastrpc_map_put(map);
err:
        kfree(args);

        return err;
}

static struct fastrpc_session_ctx *fastrpc_session_alloc(
                                        struct fastrpc_user *fl)
{
        struct fastrpc_channel_ctx *cctx = fl->cctx;
        struct fastrpc_session_ctx *session = NULL;
        unsigned long flags;
        int i;

        spin_lock_irqsave(&cctx->lock, flags);
        for (i = 0; i < cctx->sesscount; i++) {
                if (!cctx->session[i].used && cctx->session[i].valid) {
                        cctx->session[i].used = true;
                        session = &cctx->session[i];
                        /* any non-zero ID will work, session_idx + 1 is the simplest one */
                        fl->client_id = i + 1;
                        break;
                }
        }
        spin_unlock_irqrestore(&cctx->lock, flags);

        return session;
}

static void fastrpc_session_free(struct fastrpc_channel_ctx *cctx,
                                 struct fastrpc_session_ctx *session)
{
        unsigned long flags;

        spin_lock_irqsave(&cctx->lock, flags);
        session->used = false;
        spin_unlock_irqrestore(&cctx->lock, flags);
}

static int fastrpc_release_current_dsp_process(struct fastrpc_user *fl)
{
        struct fastrpc_invoke_args args[1];
        int client_id = 0;
        u32 sc;

        client_id = fl->client_id;
        args[0].ptr = (u64)(uintptr_t) &client_id;
        args[0].length = sizeof(client_id);
        args[0].fd = -1;
        sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_RELEASE, 1, 0);

        return fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE,
                                       sc, &args[0]);
}

static int fastrpc_device_release(struct inode *inode, struct file *file)
{
        struct fastrpc_user *fl = (struct fastrpc_user *)file->private_data;
        struct fastrpc_channel_ctx *cctx = fl->cctx;
        struct fastrpc_invoke_ctx *ctx, *n;
        struct fastrpc_map *map, *m;
        struct fastrpc_buf *buf, *b;
        unsigned long flags;

        fastrpc_release_current_dsp_process(fl);

        spin_lock_irqsave(&cctx->lock, flags);
        list_del(&fl->user);
        spin_unlock_irqrestore(&cctx->lock, flags);

        if (fl->init_mem)
                fastrpc_buf_free(fl->init_mem);

        list_for_each_entry_safe(ctx, n, &fl->pending, node) {
                list_del(&ctx->node);
                fastrpc_context_put(ctx);
        }

        list_for_each_entry_safe(map, m, &fl->maps, node)
                fastrpc_map_put(map);

        list_for_each_entry_safe(buf, b, &fl->mmaps, node) {
                list_del(&buf->node);
                fastrpc_buf_free(buf);
        }

        fastrpc_session_free(cctx, fl->sctx);
        fastrpc_channel_ctx_put(cctx);

        mutex_destroy(&fl->mutex);
        kfree(fl);
        file->private_data = NULL;

        return 0;
}

static int fastrpc_device_open(struct inode *inode, struct file *filp)
{
        struct fastrpc_channel_ctx *cctx;
        struct fastrpc_device *fdevice;
        struct fastrpc_user *fl = NULL;
        unsigned long flags;

        fdevice = miscdev_to_fdevice(filp->private_data);
        cctx = fdevice->cctx;

        fl = kzalloc_obj(*fl);
        if (!fl)
                return -ENOMEM;

        /* Released in fastrpc_device_release() */
        fastrpc_channel_ctx_get(cctx);

        filp->private_data = fl;
        spin_lock_init(&fl->lock);
        mutex_init(&fl->mutex);
        INIT_LIST_HEAD(&fl->pending);
        INIT_LIST_HEAD(&fl->maps);
        INIT_LIST_HEAD(&fl->mmaps);
        INIT_LIST_HEAD(&fl->user);
        fl->cctx = cctx;
        fl->is_secure_dev = fdevice->secure;

        fl->sctx = fastrpc_session_alloc(fl);
        if (!fl->sctx) {
                dev_err(&cctx->rpdev->dev, "No session available\n");
                mutex_destroy(&fl->mutex);
                kfree(fl);

                return -EBUSY;
        }

        spin_lock_irqsave(&cctx->lock, flags);
        list_add_tail(&fl->user, &cctx->users);
        spin_unlock_irqrestore(&cctx->lock, flags);

        return 0;
}

static int fastrpc_dmabuf_alloc(struct fastrpc_user *fl, char __user *argp)
{
        struct fastrpc_alloc_dma_buf bp;
        DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
        struct fastrpc_buf *buf = NULL;
        int err;

        if (copy_from_user(&bp, argp, sizeof(bp)))
                return -EFAULT;

        err = fastrpc_buf_alloc(fl, fl->sctx->dev, bp.size, &buf);
        if (err)
                return err;
        exp_info.ops = &fastrpc_dma_buf_ops;
        exp_info.size = bp.size;
        exp_info.flags = O_RDWR;
        exp_info.priv = buf;
        buf->dmabuf = dma_buf_export(&exp_info);
        if (IS_ERR(buf->dmabuf)) {
                err = PTR_ERR(buf->dmabuf);
                fastrpc_buf_free(buf);
                return err;
        }

        bp.fd = dma_buf_fd(buf->dmabuf, O_ACCMODE);
        if (bp.fd < 0) {
                dma_buf_put(buf->dmabuf);
                return -EINVAL;
        }

        if (copy_to_user(argp, &bp, sizeof(bp))) {
                /*
                 * The usercopy failed, but we can't do much about it, as
                 * dma_buf_fd() already called fd_install() and made the
                 * file descriptor accessible for the current process. It
                 * might already be closed and dmabuf no longer valid when
                 * we reach this point. Therefore "leak" the fd and rely on
                 * the process exit path to do any required cleanup.
                 */
                return -EFAULT;
        }

        return 0;
}

static int fastrpc_init_attach(struct fastrpc_user *fl, int pd)
{
        struct fastrpc_invoke_args args[1];
        int client_id = fl->client_id;
        u32 sc;

        args[0].ptr = (u64)(uintptr_t) &client_id;
        args[0].length = sizeof(client_id);
        args[0].fd = -1;
        sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_ATTACH, 1, 0);
        fl->pd = pd;

        return fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE,
                                       sc, &args[0]);
}

static int fastrpc_invoke(struct fastrpc_user *fl, char __user *argp)
{
        struct fastrpc_invoke_args *args = NULL;
        struct fastrpc_invoke inv;
        u32 nscalars;
        int err;

        if (copy_from_user(&inv, argp, sizeof(inv)))
                return -EFAULT;

        /* nscalars is truncated here to max supported value */
        nscalars = REMOTE_SCALARS_LENGTH(inv.sc);
        if (nscalars) {
                args = kzalloc_objs(*args, nscalars);
                if (!args)
                        return -ENOMEM;

                if (copy_from_user(args, (void __user *)(uintptr_t)inv.args,
                                   nscalars * sizeof(*args))) {
                        kfree(args);
                        return -EFAULT;
                }
        }

        err = fastrpc_internal_invoke(fl, false, inv.handle, inv.sc, args);
        kfree(args);

        return err;
}

static int fastrpc_get_info_from_dsp(struct fastrpc_user *fl, uint32_t *dsp_attr_buf,
                                     uint32_t dsp_attr_buf_len)
{
        struct fastrpc_invoke_args args[2] = { 0 };

        /*
         * Capability filled in userspace. This carries the information
         * about the remoteproc support which is fetched from the remoteproc
         * sysfs node by userspace.
         */
        dsp_attr_buf[0] = 0;
        dsp_attr_buf_len -= 1;

        args[0].ptr = (u64)(uintptr_t)&dsp_attr_buf_len;
        args[0].length = sizeof(dsp_attr_buf_len);
        args[0].fd = -1;
        args[1].ptr = (u64)(uintptr_t)&dsp_attr_buf[1];
        args[1].length = dsp_attr_buf_len * sizeof(u32);
        args[1].fd = -1;

        return fastrpc_internal_invoke(fl, true, FASTRPC_DSP_UTILITIES_HANDLE,
                                       FASTRPC_SCALARS(0, 1, 1), args);
}

static int fastrpc_get_info_from_kernel(struct fastrpc_ioctl_capability *cap,
                                        struct fastrpc_user *fl)
{
        struct fastrpc_channel_ctx *cctx = fl->cctx;
        uint32_t attribute_id = cap->attribute_id;
        uint32_t *dsp_attributes;
        unsigned long flags;
        int err;

        spin_lock_irqsave(&cctx->lock, flags);
        /* check if we already have queried dsp for attributes */
        if (cctx->valid_attributes) {
                spin_unlock_irqrestore(&cctx->lock, flags);
                goto done;
        }
        spin_unlock_irqrestore(&cctx->lock, flags);

        dsp_attributes = kzalloc(FASTRPC_MAX_DSP_ATTRIBUTES_LEN, GFP_KERNEL);
        if (!dsp_attributes)
                return -ENOMEM;

        err = fastrpc_get_info_from_dsp(fl, dsp_attributes, FASTRPC_MAX_DSP_ATTRIBUTES);
        if (err == DSP_UNSUPPORTED_API) {
                dev_info(&cctx->rpdev->dev,
                         "Warning: DSP capabilities not supported\n");
                kfree(dsp_attributes);
                return -EOPNOTSUPP;
        } else if (err) {
                dev_err(&cctx->rpdev->dev, "Error: dsp information is incorrect err: %d\n", err);
                kfree(dsp_attributes);
                return err;
        }

        spin_lock_irqsave(&cctx->lock, flags);
        memcpy(cctx->dsp_attributes, dsp_attributes, FASTRPC_MAX_DSP_ATTRIBUTES_LEN);
        cctx->valid_attributes = true;
        spin_unlock_irqrestore(&cctx->lock, flags);
        kfree(dsp_attributes);
done:
        cap->capability = cctx->dsp_attributes[attribute_id];
        return 0;
}

static int fastrpc_get_dsp_info(struct fastrpc_user *fl, char __user *argp)
{
        struct fastrpc_ioctl_capability cap = {0};
        int err = 0;

        if (copy_from_user(&cap, argp, sizeof(cap)))
                return  -EFAULT;

        cap.capability = 0;

        if (cap.attribute_id >= FASTRPC_MAX_DSP_ATTRIBUTES) {
                dev_err(&fl->cctx->rpdev->dev, "Error: invalid attribute: %d, err: %d\n",
                        cap.attribute_id, err);
                return -EOVERFLOW;
        }

        err = fastrpc_get_info_from_kernel(&cap, fl);
        if (err)
                return err;

        if (copy_to_user(argp, &cap, sizeof(cap)))
                return -EFAULT;

        return 0;
}

static int fastrpc_req_munmap_impl(struct fastrpc_user *fl, struct fastrpc_buf *buf)
{
        struct fastrpc_invoke_args args[1] = { [0] = { 0 } };
        struct fastrpc_munmap_req_msg req_msg;
        struct device *dev = fl->sctx->dev;
        int err;
        u32 sc;

        req_msg.client_id = fl->client_id;
        req_msg.size = buf->size;
        req_msg.vaddr = buf->raddr;

        args[0].ptr = (u64) (uintptr_t) &req_msg;
        args[0].length = sizeof(req_msg);

        sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_MUNMAP, 1, 0);
        err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc,
                                      &args[0]);
        if (!err) {
                dev_dbg(dev, "unmmap\tpt 0x%09lx OK\n", buf->raddr);
                spin_lock(&fl->lock);
                list_del(&buf->node);
                spin_unlock(&fl->lock);
                fastrpc_buf_free(buf);
        } else {
                dev_err(dev, "unmmap\tpt 0x%09lx ERROR\n", buf->raddr);
        }

        return err;
}

static int fastrpc_req_munmap(struct fastrpc_user *fl, char __user *argp)
{
        struct fastrpc_buf *buf = NULL, *iter, *b;
        struct fastrpc_req_munmap req;
        struct device *dev = fl->sctx->dev;

        if (copy_from_user(&req, argp, sizeof(req)))
                return -EFAULT;

        spin_lock(&fl->lock);
        list_for_each_entry_safe(iter, b, &fl->mmaps, node) {
                if ((iter->raddr == req.vaddrout) && (iter->size == req.size)) {
                        buf = iter;
                        break;
                }
        }
        spin_unlock(&fl->lock);

        if (!buf) {
                dev_err(dev, "mmap\t\tpt 0x%09llx [len 0x%08llx] not in list\n",
                        req.vaddrout, req.size);
                return -EINVAL;
        }

        return fastrpc_req_munmap_impl(fl, buf);
}

static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
{
        struct fastrpc_invoke_args args[3] = { [0 ... 2] = { 0 } };
        struct fastrpc_buf *buf = NULL;
        struct fastrpc_mmap_req_msg req_msg;
        struct fastrpc_mmap_rsp_msg rsp_msg;
        struct fastrpc_phy_page pages;
        struct fastrpc_req_mmap req;
        struct device *dev = fl->sctx->dev;
        int err;
        u32 sc;

        if (copy_from_user(&req, argp, sizeof(req)))
                return -EFAULT;

        if (req.flags != ADSP_MMAP_ADD_PAGES && req.flags != ADSP_MMAP_REMOTE_HEAP_ADDR) {
                dev_err(dev, "flag not supported 0x%x\n", req.flags);

                return -EINVAL;
        }

        if (req.vaddrin) {
                dev_err(dev, "adding user allocated pages is not supported\n");
                return -EINVAL;
        }

        if (req.flags == ADSP_MMAP_REMOTE_HEAP_ADDR)
                err = fastrpc_remote_heap_alloc(fl, dev, req.size, &buf);
        else
                err = fastrpc_buf_alloc(fl, dev, req.size, &buf);

        if (err) {
                dev_err(dev, "failed to allocate buffer\n");
                return err;
        }

        req_msg.client_id = fl->client_id;
        req_msg.flags = req.flags;
        req_msg.vaddr = req.vaddrin;
        req_msg.num = sizeof(pages);

        args[0].ptr = (u64) (uintptr_t) &req_msg;
        args[0].length = sizeof(req_msg);

        pages.addr = buf->dma_addr;
        pages.size = buf->size;

        args[1].ptr = (u64) (uintptr_t) &pages;
        args[1].length = sizeof(pages);

        args[2].ptr = (u64) (uintptr_t) &rsp_msg;
        args[2].length = sizeof(rsp_msg);

        sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_MMAP, 2, 1);
        err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc,
                                      &args[0]);
        if (err) {
                dev_err(dev, "mmap error (len 0x%08llx)\n", buf->size);
                fastrpc_buf_free(buf);
                return err;
        }

        /* update the buffer to be able to deallocate the memory on the DSP */
        buf->raddr = (uintptr_t) rsp_msg.vaddr;

        /* let the client know the address to use */
        req.vaddrout = rsp_msg.vaddr;

        /* Add memory to static PD pool, protection thru hypervisor */
        if (req.flags == ADSP_MMAP_REMOTE_HEAP_ADDR && fl->cctx->vmcount) {
                u64 src_perms = BIT(QCOM_SCM_VMID_HLOS);

                err = qcom_scm_assign_mem(buf->dma_addr, (u64)buf->size,
                        &src_perms, fl->cctx->vmperms, fl->cctx->vmcount);
                if (err) {
                        dev_err(fl->sctx->dev,
                                "Failed to assign memory dma_addr %pad size 0x%llx err %d",
                                &buf->dma_addr, buf->size, err);
                        goto err_assign;
                }
        }

        spin_lock(&fl->lock);
        list_add_tail(&buf->node, &fl->mmaps);
        spin_unlock(&fl->lock);

        if (copy_to_user((void __user *)argp, &req, sizeof(req))) {
                err = -EFAULT;
                goto err_assign;
        }

        dev_dbg(dev, "mmap\t\tpt 0x%09lx OK [len 0x%08llx]\n",
                buf->raddr, buf->size);

        return 0;

err_assign:
        fastrpc_req_munmap_impl(fl, buf);

        return err;
}

static int fastrpc_req_mem_unmap_impl(struct fastrpc_user *fl, struct fastrpc_mem_unmap *req)
{
        struct fastrpc_invoke_args args[1] = { [0] = { 0 } };
        struct fastrpc_map *map = NULL, *iter, *m;
        struct fastrpc_mem_unmap_req_msg req_msg = { 0 };
        int err = 0;
        u32 sc;
        struct device *dev = fl->sctx->dev;

        spin_lock(&fl->lock);
        list_for_each_entry_safe(iter, m, &fl->maps, node) {
                if ((req->fd < 0 || iter->fd == req->fd) && (iter->raddr == req->vaddr)) {
                        map = iter;
                        break;
                }
        }

        spin_unlock(&fl->lock);

        if (!map) {
                dev_err(dev, "map not in list\n");
                return -EINVAL;
        }

        req_msg.client_id = fl->client_id;
        req_msg.len = map->len;
        req_msg.vaddrin = map->raddr;
        req_msg.fd = map->fd;

        args[0].ptr = (u64) (uintptr_t) &req_msg;
        args[0].length = sizeof(req_msg);

        sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_MEM_UNMAP, 1, 0);
        err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc,
                                      &args[0]);
        if (err) {
                dev_err(dev, "unmmap\tpt fd = %d, 0x%09llx error\n",  map->fd, map->raddr);
                return err;
        }
        fastrpc_map_put(map);

        return 0;
}

static int fastrpc_req_mem_unmap(struct fastrpc_user *fl, char __user *argp)
{
        struct fastrpc_mem_unmap req;

        if (copy_from_user(&req, argp, sizeof(req)))
                return -EFAULT;

        return fastrpc_req_mem_unmap_impl(fl, &req);
}

static int fastrpc_req_mem_map(struct fastrpc_user *fl, char __user *argp)
{
        struct fastrpc_invoke_args args[4] = { [0 ... 3] = { 0 } };
        struct fastrpc_mem_map_req_msg req_msg = { 0 };
        struct fastrpc_mmap_rsp_msg rsp_msg = { 0 };
        struct fastrpc_mem_unmap req_unmap = { 0 };
        struct fastrpc_phy_page pages = { 0 };
        struct fastrpc_mem_map req;
        struct device *dev = fl->sctx->dev;
        struct fastrpc_map *map = NULL;
        int err;
        u32 sc;

        if (copy_from_user(&req, argp, sizeof(req)))
                return -EFAULT;

        /* create SMMU mapping */
        err = fastrpc_map_create(fl, req.fd, req.length, 0, &map);
        if (err) {
                dev_err(dev, "failed to map buffer, fd = %d\n", req.fd);
                return err;
        }

        req_msg.client_id = fl->client_id;
        req_msg.fd = req.fd;
        req_msg.offset = req.offset;
        req_msg.vaddrin = req.vaddrin;
        map->va = (void *) (uintptr_t) req.vaddrin;
        req_msg.flags = req.flags;
        req_msg.num = sizeof(pages);
        req_msg.data_len = 0;

        args[0].ptr = (u64) (uintptr_t) &req_msg;
        args[0].length = sizeof(req_msg);

        pages.addr = map->dma_addr;
        pages.size = map->len;

        args[1].ptr = (u64) (uintptr_t) &pages;
        args[1].length = sizeof(pages);

        args[2].ptr = (u64) (uintptr_t) &pages;
        args[2].length = 0;

        args[3].ptr = (u64) (uintptr_t) &rsp_msg;
        args[3].length = sizeof(rsp_msg);

        sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_MEM_MAP, 3, 1);
        err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE, sc, &args[0]);
        if (err) {
                dev_err(dev, "mem mmap error, fd %d, vaddr %llx, size %lld\n",
                        req.fd, req.vaddrin, map->len);
                goto err_invoke;
        }

        /* update the buffer to be able to deallocate the memory on the DSP */
        map->raddr = rsp_msg.vaddr;

        /* let the client know the address to use */
        req.vaddrout = rsp_msg.vaddr;

        if (copy_to_user((void __user *)argp, &req, sizeof(req))) {
                /* unmap the memory and release the buffer */
                req_unmap.vaddr = (uintptr_t) rsp_msg.vaddr;
                req_unmap.length = map->len;
                fastrpc_req_mem_unmap_impl(fl, &req_unmap);
                return -EFAULT;
        }

        return 0;

err_invoke:
        fastrpc_map_put(map);

        return err;
}

static long fastrpc_device_ioctl(struct file *file, unsigned int cmd,
                                 unsigned long arg)
{
        struct fastrpc_user *fl = (struct fastrpc_user *)file->private_data;
        char __user *argp = (char __user *)arg;
        int err;

        switch (cmd) {
        case FASTRPC_IOCTL_INVOKE:
                err = fastrpc_invoke(fl, argp);
                break;
        case FASTRPC_IOCTL_INIT_ATTACH:
                err = fastrpc_init_attach(fl, ROOT_PD);
                break;
        case FASTRPC_IOCTL_INIT_ATTACH_SNS:
                err = fastrpc_init_attach(fl, SENSORS_PD);
                break;
        case FASTRPC_IOCTL_INIT_CREATE_STATIC:
                err = fastrpc_init_create_static_process(fl, argp);
                break;
        case FASTRPC_IOCTL_INIT_CREATE:
                err = fastrpc_init_create_process(fl, argp);
                break;
        case FASTRPC_IOCTL_ALLOC_DMA_BUFF:
                err = fastrpc_dmabuf_alloc(fl, argp);
                break;
        case FASTRPC_IOCTL_MMAP:
                err = fastrpc_req_mmap(fl, argp);
                break;
        case FASTRPC_IOCTL_MUNMAP:
                err = fastrpc_req_munmap(fl, argp);
                break;
        case FASTRPC_IOCTL_MEM_MAP:
                err = fastrpc_req_mem_map(fl, argp);
                break;
        case FASTRPC_IOCTL_MEM_UNMAP:
                err = fastrpc_req_mem_unmap(fl, argp);
                break;
        case FASTRPC_IOCTL_GET_DSP_INFO:
                err = fastrpc_get_dsp_info(fl, argp);
                break;
        default:
                err = -ENOTTY;
                break;
        }

        return err;
}

static const struct file_operations fastrpc_fops = {
        .open = fastrpc_device_open,
        .release = fastrpc_device_release,
        .unlocked_ioctl = fastrpc_device_ioctl,
        .compat_ioctl = fastrpc_device_ioctl,
};

static int fastrpc_cb_probe(struct platform_device *pdev)
{
        struct fastrpc_channel_ctx *cctx;
        struct fastrpc_session_ctx *sess;
        struct device *dev = &pdev->dev;
        int i, sessions = 0;
        unsigned long flags;
        int rc;
        u32 dma_bits;

        cctx = dev_get_drvdata(dev->parent);
        if (!cctx)
                return -EINVAL;

        of_property_read_u32(dev->of_node, "qcom,nsessions", &sessions);

        spin_lock_irqsave(&cctx->lock, flags);
        if (cctx->sesscount >= FASTRPC_MAX_SESSIONS) {
                dev_err(&pdev->dev, "too many sessions\n");
                spin_unlock_irqrestore(&cctx->lock, flags);
                return -ENOSPC;
        }
        dma_bits = cctx->soc_data->dma_addr_bits_default;
        sess = &cctx->session[cctx->sesscount++];
        sess->used = false;
        sess->valid = true;
        sess->dev = dev;
        dev_set_drvdata(dev, sess);

        if (cctx->domain_id == CDSP_DOMAIN_ID)
                dma_bits = cctx->soc_data->dma_addr_bits_cdsp;

        if (of_property_read_u32(dev->of_node, "reg", &sess->sid))
                dev_info(dev, "FastRPC Session ID not specified in DT\n");

        if (sessions > 0) {
                struct fastrpc_session_ctx *dup_sess;

                for (i = 1; i < sessions; i++) {
                        if (cctx->sesscount >= FASTRPC_MAX_SESSIONS)
                                break;
                        dup_sess = &cctx->session[cctx->sesscount++];
                        memcpy(dup_sess, sess, sizeof(*dup_sess));
                }
        }
        spin_unlock_irqrestore(&cctx->lock, flags);
        rc = dma_set_mask(dev, DMA_BIT_MASK(dma_bits));
        if (rc) {
                dev_err(dev, "%u-bit DMA enable failed\n", dma_bits);
                return rc;
        }

        return 0;
}

static void fastrpc_cb_remove(struct platform_device *pdev)
{
        struct fastrpc_channel_ctx *cctx = dev_get_drvdata(pdev->dev.parent);
        struct fastrpc_session_ctx *sess = dev_get_drvdata(&pdev->dev);
        unsigned long flags;
        int i;

        spin_lock_irqsave(&cctx->lock, flags);
        for (i = 0; i < FASTRPC_MAX_SESSIONS; i++) {
                if (cctx->session[i].sid == sess->sid) {
                        cctx->session[i].valid = false;
                        cctx->sesscount--;
                }
        }
        spin_unlock_irqrestore(&cctx->lock, flags);
}

static const struct of_device_id fastrpc_match_table[] = {
        { .compatible = "qcom,fastrpc-compute-cb", },
        {}
};

static struct platform_driver fastrpc_cb_driver = {
        .probe = fastrpc_cb_probe,
        .remove = fastrpc_cb_remove,
        .driver = {
                .name = "qcom,fastrpc-cb",
                .of_match_table = fastrpc_match_table,
                .suppress_bind_attrs = true,
        },
};

static int fastrpc_device_register(struct device *dev, struct fastrpc_channel_ctx *cctx,
                                   bool is_secured, const char *domain)
{
        struct fastrpc_device *fdev;
        int err;

        fdev = devm_kzalloc(dev, sizeof(*fdev), GFP_KERNEL);
        if (!fdev)
                return -ENOMEM;

        fdev->secure = is_secured;
        fdev->cctx = cctx;
        fdev->miscdev.minor = MISC_DYNAMIC_MINOR;
        fdev->miscdev.fops = &fastrpc_fops;
        fdev->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "fastrpc-%s%s",
                                            domain, is_secured ? "-secure" : "");
        if (!fdev->miscdev.name)
                return -ENOMEM;

        err = misc_register(&fdev->miscdev);
        if (!err) {
                if (is_secured)
                        cctx->secure_fdevice = fdev;
                else
                        cctx->fdevice = fdev;
        }

        return err;
}

static int fastrpc_get_domain_id(const char *domain)
{
        if (!strncmp(domain, "adsp", 4))
                return ADSP_DOMAIN_ID;
        else if (!strncmp(domain, "cdsp", 4))
                return CDSP_DOMAIN_ID;
        else if (!strncmp(domain, "mdsp", 4))
                return MDSP_DOMAIN_ID;
        else if (!strncmp(domain, "sdsp", 4))
                return SDSP_DOMAIN_ID;
        else if (!strncmp(domain, "gdsp", 4))
                return GDSP_DOMAIN_ID;

        return -EINVAL;
}

static const struct fastrpc_soc_data kaanapali_soc_data = {
        .sid_pos = 56,
        .dma_addr_bits_cdsp = 34,
        .dma_addr_bits_default = 32,
};

static const struct fastrpc_soc_data default_soc_data = {
        .sid_pos = 32,
        .dma_addr_bits_cdsp = 32,
        .dma_addr_bits_default = 32,
};

static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev)
{
        struct device *rdev = &rpdev->dev;
        struct fastrpc_channel_ctx *data;
        int i, err, domain_id = -1, vmcount;
        const char *domain;
        bool secure_dsp;
        unsigned int vmids[FASTRPC_MAX_VMIDS];
        const struct fastrpc_soc_data *soc_data;

        soc_data = device_get_match_data(rdev);

        err = of_property_read_string(rdev->of_node, "label", &domain);
        if (err) {
                dev_info(rdev, "FastRPC Domain not specified in DT\n");
                return err;
        }

        domain_id = fastrpc_get_domain_id(domain);

        if (domain_id < 0) {
                dev_info(rdev, "FastRPC Domain %s not supported\n", domain);
                return -EINVAL;
        }

        if (of_reserved_mem_device_init_by_idx(rdev, rdev->of_node, 0))
                dev_info(rdev, "no reserved DMA memory for FASTRPC\n");

        vmcount = of_property_read_variable_u32_array(rdev->of_node,
                                "qcom,vmids", &vmids[0], 0, FASTRPC_MAX_VMIDS);
        if (vmcount < 0)
                vmcount = 0;
        else if (!qcom_scm_is_available())
                return -EPROBE_DEFER;

        data = kzalloc_obj(*data);
        if (!data)
                return -ENOMEM;

        if (vmcount) {
                data->vmcount = vmcount;
                for (i = 0; i < data->vmcount; i++) {
                        data->vmperms[i].vmid = vmids[i];
                        data->vmperms[i].perm = QCOM_SCM_PERM_RWX;
                }
        }

        if (domain_id == SDSP_DOMAIN_ID) {
                struct resource res;
                u64 src_perms;

                err = of_reserved_mem_region_to_resource(rdev->of_node, 0, &res);
                if (!err) {
                        src_perms = BIT(QCOM_SCM_VMID_HLOS);

                        err = qcom_scm_assign_mem(res.start, resource_size(&res), &src_perms,
                                    data->vmperms, data->vmcount);
                        if (err)
                                goto err_free_data;
                }

        }

        secure_dsp = !(of_property_read_bool(rdev->of_node, "qcom,non-secure-domain"));
        data->secure = secure_dsp;
        data->soc_data = soc_data;

        switch (domain_id) {
        case ADSP_DOMAIN_ID:
        case MDSP_DOMAIN_ID:
        case SDSP_DOMAIN_ID:
                /* Unsigned PD offloading is only supported on CDSP and GDSP */
                data->unsigned_support = false;
                err = fastrpc_device_register(rdev, data, secure_dsp, domain);
                if (err)
                        goto err_free_data;
                break;
        case CDSP_DOMAIN_ID:
        case GDSP_DOMAIN_ID:
                data->unsigned_support = true;
                /* Create both device nodes so that we can allow both Signed and Unsigned PD */
                err = fastrpc_device_register(rdev, data, true, domain);
                if (err)
                        goto err_free_data;

                err = fastrpc_device_register(rdev, data, false, domain);
                if (err)
                        goto err_deregister_fdev;
                break;
        default:
                err = -EINVAL;
                goto err_free_data;
        }

        kref_init(&data->refcount);

        dev_set_drvdata(&rpdev->dev, data);
        rdev->dma_mask = &data->dma_mask;
        dma_set_mask_and_coherent(rdev, DMA_BIT_MASK(32));
        INIT_LIST_HEAD(&data->users);
        INIT_LIST_HEAD(&data->invoke_interrupted_mmaps);
        spin_lock_init(&data->lock);
        idr_init(&data->ctx_idr);
        data->domain_id = domain_id;
        data->rpdev = rpdev;

        err = of_platform_populate(rdev->of_node, NULL, NULL, rdev);
        if (err)
                goto err_deregister_fdev;

        return 0;

err_deregister_fdev:
        if (data->fdevice)
                misc_deregister(&data->fdevice->miscdev);
        if (data->secure_fdevice)
                misc_deregister(&data->secure_fdevice->miscdev);

err_free_data:
        kfree(data);
        return err;
}

static void fastrpc_notify_users(struct fastrpc_user *user)
{
        struct fastrpc_invoke_ctx *ctx;

        spin_lock(&user->lock);
        list_for_each_entry(ctx, &user->pending, node) {
                ctx->retval = -EPIPE;
                complete(&ctx->work);
        }
        spin_unlock(&user->lock);
}

static void fastrpc_rpmsg_remove(struct rpmsg_device *rpdev)
{
        struct fastrpc_channel_ctx *cctx = dev_get_drvdata(&rpdev->dev);
        struct fastrpc_buf *buf, *b;
        struct fastrpc_user *user;
        unsigned long flags;

        /* No invocations past this point */
        spin_lock_irqsave(&cctx->lock, flags);
        cctx->rpdev = NULL;
        list_for_each_entry(user, &cctx->users, user)
                fastrpc_notify_users(user);
        spin_unlock_irqrestore(&cctx->lock, flags);

        if (cctx->fdevice)
                misc_deregister(&cctx->fdevice->miscdev);

        if (cctx->secure_fdevice)
                misc_deregister(&cctx->secure_fdevice->miscdev);

        list_for_each_entry_safe(buf, b, &cctx->invoke_interrupted_mmaps, node)
                list_del(&buf->node);

        if (cctx->remote_heap)
                fastrpc_buf_free(cctx->remote_heap);

        of_platform_depopulate(&rpdev->dev);

        fastrpc_channel_ctx_put(cctx);
}

static int fastrpc_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
                                  int len, void *priv, u32 addr)
{
        struct fastrpc_channel_ctx *cctx = dev_get_drvdata(&rpdev->dev);
        struct fastrpc_invoke_rsp *rsp = data;
        struct fastrpc_invoke_ctx *ctx;
        unsigned long flags;
        unsigned long ctxid;

        if (len < sizeof(*rsp))
                return -EINVAL;

        ctxid = ((rsp->ctx & FASTRPC_CTXID_MASK) >> 4);

        spin_lock_irqsave(&cctx->lock, flags);
        ctx = idr_find(&cctx->ctx_idr, ctxid);
        spin_unlock_irqrestore(&cctx->lock, flags);

        if (!ctx) {
                dev_err(&rpdev->dev, "No context ID matches response\n");
                return -ENOENT;
        }

        ctx->retval = rsp->retval;
        complete(&ctx->work);

        /*
         * The DMA buffer associated with the context cannot be freed in
         * interrupt context so schedule it through a worker thread to
         * avoid a kernel BUG.
         */
        schedule_work(&ctx->put_work);

        return 0;
}

static const struct of_device_id fastrpc_rpmsg_of_match[] = {
        { .compatible = "qcom,kaanapali-fastrpc", .data = &kaanapali_soc_data },
        { .compatible = "qcom,fastrpc", .data = &default_soc_data },
        { },
};
MODULE_DEVICE_TABLE(of, fastrpc_rpmsg_of_match);

static struct rpmsg_driver fastrpc_driver = {
        .probe = fastrpc_rpmsg_probe,
        .remove = fastrpc_rpmsg_remove,
        .callback = fastrpc_rpmsg_callback,
        .drv = {
                .name = "qcom,fastrpc",
                .of_match_table = fastrpc_rpmsg_of_match,
        },
};

static int fastrpc_init(void)
{
        int ret;

        ret = platform_driver_register(&fastrpc_cb_driver);
        if (ret < 0) {
                pr_err("fastrpc: failed to register cb driver\n");
                return ret;
        }

        ret = register_rpmsg_driver(&fastrpc_driver);
        if (ret < 0) {
                pr_err("fastrpc: failed to register rpmsg driver\n");
                platform_driver_unregister(&fastrpc_cb_driver);
                return ret;
        }

        return 0;
}
module_init(fastrpc_init);

static void fastrpc_exit(void)
{
        platform_driver_unregister(&fastrpc_cb_driver);
        unregister_rpmsg_driver(&fastrpc_driver);
}
module_exit(fastrpc_exit);

MODULE_DESCRIPTION("Qualcomm FastRPC");
MODULE_LICENSE("GPL v2");
MODULE_IMPORT_NS("DMA_BUF");