Merge tag 'char-misc-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the big char/misc driver patch pull request for 5.1-rc1.

  The largest thing by far is the new habanalabs driver for their AI
  accelerator chip. For now it is in the drivers/misc directory but will
  probably move to a new directory soon along with other drivers of this
  type.

  Other than that, just the usual set of individual driver updates and
  fixes. There's an "odd" merge in here from the DRM tree that they
  asked me to do as the MEI driver is starting to interact with the i915
  driver, and it needed some coordination. All of those patches have
  been properly acked by the relevant subsystem maintainers.

  All of these have been in linux-next with no reported issues, most for
  quite some time"

* tag 'char-misc-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (219 commits)
  habanalabs: adjust Kconfig to fix build errors
  habanalabs: use %px instead of %p in error print
  habanalabs: use do_div for 64-bit divisions
  intel_th: gth: Fix an off-by-one in output unassigning
  habanalabs: fix little-endian<->cpu conversion warnings
  habanalabs: use NULL to initialize array of pointers
  habanalabs: fix little-endian<->cpu conversion warnings
  habanalabs: soft-reset device if context-switch fails
  habanalabs: print pointer using %p
  habanalabs: fix memory leak with CBs with unaligned size
  habanalabs: return correct error code on MMU mapping failure
  habanalabs: add comments in uapi/misc/habanalabs.h
  habanalabs: extend QMAN0 job timeout
  habanalabs: set DMA0 completion to SOB 1007
  habanalabs: fix validation of WREG32 to DMA completion
  habanalabs: fix mmu cache registers init
  habanalabs: disable CPU access on timeouts
  habanalabs: add MMU DRAM default page mapping
  habanalabs: Dissociate RAZWI info from event types
  misc/habanalabs: adjust Kconfig to fix build errors
  ...

1 files changed, 1401 insertions, 0 deletions

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
new file mode 100644
index 000000000000..39f832d27288
--- /dev/null
+++ b/drivers/misc/fastrpc.c
@@ -0,0 +1,1401 @@
+// 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/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/of_platform.h>
+#include <linux/rpmsg.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <uapi/misc/fastrpc.h>
+
+#define ADSP_DOMAIN_ID (0)
+#define MDSP_DOMAIN_ID (1)
+#define SDSP_DOMAIN_ID (2)
+#define CDSP_DOMAIN_ID (3)
+#define FASTRPC_DEV_MAX		4 /* adsp, mdsp, slpi, cdsp*/
+#define FASTRPC_MAX_SESSIONS	9 /*8 compute, 1 cpz*/
+#define FASTRPC_ALIGN		128
+#define FASTRPC_MAX_FDLIST	16
+#define FASTRPC_MAX_CRCLIST	64
+#define FASTRPC_PHYS(p)	((p) & 0xffffffff)
+#define FASTRPC_CTX_MAX (256)
+#define FASTRPC_INIT_HANDLE	1
+#define FASTRPC_CTXID_MASK (0xFF0)
+#define INIT_FILELEN_MAX (2 * 1024 * 1024)
+#define INIT_MEMLEN_MAX  (8 * 1024 * 1024)
+#define FASTRPC_DEVICE_NAME	"fastrpc"
+
+/* 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
+/* Remote Method id table */
+#define FASTRPC_RMID_INIT_ATTACH	0
+#define FASTRPC_RMID_INIT_RELEASE	1
+#define FASTRPC_RMID_INIT_CREATE	6
+#define FASTRPC_RMID_INIT_CREATE_ATTR	7
+#define FASTRPC_RMID_INIT_CREATE_STATIC	8
+
+#define miscdev_to_cctx(d) container_of(d, struct fastrpc_channel_ctx, miscdev)
+
+static const char *domains[FASTRPC_DEV_MAX] = { "adsp", "mdsp",
+						"sdsp", "cdsp"};
+struct fastrpc_phy_page {
+	u64 addr;		/* physical 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_arg {
+	u64 pv;
+	u64 len;
+};
+
+struct fastrpc_msg {
+	int pid;		/* process group id */
+	int tid;		/* thread id */
+	u64 ctx;		/* invoke caller context */
+	u32 handle;	/* handle to invoke */
+	u32 sc;		/* scalars structure describing the data */
+	u64 addr;		/* physical address */
+	u64 size;		/* size of contiguous region */
+};
+
+struct fastrpc_invoke_rsp {
+	u64 ctx;		/* invoke caller context */
+	int retval;		/* invoke return value */
+};
+
+struct fastrpc_buf {
+	struct fastrpc_user *fl;
+	struct dma_buf *dmabuf;
+	struct device *dev;
+	void *virt;
+	u64 phys;
+	u64 size;
+	/* Lock for dma buf attachments */
+	struct mutex lock;
+	struct list_head attachments;
+};
+
+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;
+	u64 phys;
+	u64 size;
+	void *va;
+	u64 len;
+	struct kref refcount;
+};
+
+struct fastrpc_invoke_ctx {
+	int nscalars;
+	int nbufs;
+	int retval;
+	int pid;
+	int tgid;
+	u32 sc;
+	u32 *crc;
+	u64 ctxid;
+	u64 msg_sz;
+	struct kref refcount;
+	struct list_head node; /* list of ctxs */
+	struct completion work;
+	struct fastrpc_msg msg;
+	struct fastrpc_user *fl;
+	struct fastrpc_remote_arg *rpra;
+	struct fastrpc_map **maps;
+	struct fastrpc_buf *buf;
+	struct fastrpc_invoke_args *args;
+	struct fastrpc_channel_ctx *cctx;
+};
+
+struct fastrpc_session_ctx {
+	struct device *dev;
+	int sid;
+	bool used;
+	bool valid;
+};
+
+struct fastrpc_channel_ctx {
+	int domain_id;
+	int sesscount;
+	struct rpmsg_device *rpdev;
+	struct fastrpc_session_ctx session[FASTRPC_MAX_SESSIONS];
+	spinlock_t lock;
+	struct idr ctx_idr;
+	struct list_head users;
+	struct miscdevice miscdev;
+};
+
+struct fastrpc_user {
+	struct list_head user;
+	struct list_head maps;
+	struct list_head pending;
+
+	struct fastrpc_channel_ctx *cctx;
+	struct fastrpc_session_ctx *sctx;
+	struct fastrpc_buf *init_mem;
+
+	int tgid;
+	int pd;
+	/* Lock for lists */
+	spinlock_t lock;
+	/* lock for allocations */
+	struct mutex mutex;
+};
+
+static void fastrpc_free_map(struct kref *ref)
+{
+	struct fastrpc_map *map;
+
+	map = container_of(ref, struct fastrpc_map, refcount);
+
+	if (map->table) {
+		dma_buf_unmap_attachment(map->attach, map->table,
+					 DMA_BIDIRECTIONAL);
+		dma_buf_detach(map->buf, map->attach);
+		dma_buf_put(map->buf);
+	}
+
+	kfree(map);
+}
+
+static void fastrpc_map_put(struct fastrpc_map *map)
+{
+	if (map)
+		kref_put(&map->refcount, fastrpc_free_map);
+}
+
+static void fastrpc_map_get(struct fastrpc_map *map)
+{
+	if (map)
+		kref_get(&map->refcount);
+}
+
+static int fastrpc_map_find(struct fastrpc_user *fl, int fd,
+			    struct fastrpc_map **ppmap)
+{
+	struct fastrpc_map *map = NULL;
+
+	mutex_lock(&fl->mutex);
+	list_for_each_entry(map, &fl->maps, node) {
+		if (map->fd == fd) {
+			fastrpc_map_get(map);
+			*ppmap = map;
+			mutex_unlock(&fl->mutex);
+			return 0;
+		}
+	}
+	mutex_unlock(&fl->mutex);
+
+	return -ENOENT;
+}
+
+static void fastrpc_buf_free(struct fastrpc_buf *buf)
+{
+	dma_free_coherent(buf->dev, buf->size, buf->virt,
+			  FASTRPC_PHYS(buf->phys));
+	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(sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&buf->attachments);
+	mutex_init(&buf->lock);
+
+	buf->fl = fl;
+	buf->virt = NULL;
+	buf->phys = 0;
+	buf->size = size;
+	buf->dev = dev;
+
+	buf->virt = dma_alloc_coherent(dev, buf->size, (dma_addr_t *)&buf->phys,
+				       GFP_KERNEL);
+	if (!buf->virt)
+		return -ENOMEM;
+
+	if (fl->sctx && fl->sctx->sid)
+		buf->phys += ((u64)fl->sctx->sid << 32);
+
+	*obuf = buf;
+
+	return 0;
+}
+
+static void fastrpc_context_free(struct kref *ref)
+{
+	struct fastrpc_invoke_ctx *ctx;
+	struct fastrpc_channel_ctx *cctx;
+	int i;
+
+	ctx = container_of(ref, struct fastrpc_invoke_ctx, refcount);
+	cctx = ctx->cctx;
+
+	for (i = 0; i < ctx->nscalars; i++)
+		fastrpc_map_put(ctx->maps[i]);
+
+	if (ctx->buf)
+		fastrpc_buf_free(ctx->buf);
+
+	spin_lock(&cctx->lock);
+	idr_remove(&cctx->ctx_idr, ctx->ctxid >> 4);
+	spin_unlock(&cctx->lock);
+
+	kfree(ctx->maps);
+	kfree(ctx);
+}
+
+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 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;
+	int ret;
+
+	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+	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 = kcalloc(ctx->nscalars,
+				    sizeof(*ctx->maps), GFP_KERNEL);
+		if (!ctx->maps) {
+			kfree(ctx);
+			return ERR_PTR(-ENOMEM);
+		}
+		ctx->args = args;
+	}
+
+	ctx->sc = sc;
+	ctx->retval = -1;
+	ctx->pid = current->pid;
+	ctx->tgid = user->tgid;
+	ctx->cctx = cctx;
+	init_completion(&ctx->work);
+
+	spin_lock(&user->lock);
+	list_add_tail(&ctx->node, &user->pending);
+	spin_unlock(&user->lock);
+
+	spin_lock(&cctx->lock);
+	ret = idr_alloc_cyclic(&cctx->ctx_idr, ctx, 1,
+			       FASTRPC_CTX_MAX, GFP_ATOMIC);
+	if (ret < 0) {
+		spin_unlock(&cctx->lock);
+		goto err_idr;
+	}
+	ctx->ctxid = ret << 4;
+	spin_unlock(&cctx->lock);
+
+	kref_init(&ctx->refcount);
+
+	return ctx;
+err_idr:
+	spin_lock(&user->lock);
+	list_del(&ctx->node);
+	spin_unlock(&user->lock);
+	kfree(ctx->maps);
+	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;
+
+	table = &a->sgt;
+
+	if (!dma_map_sg(attachment->dev, table->sgl, table->nents, dir))
+		return ERR_PTR(-ENOMEM);
+
+	return table;
+}
+
+static void fastrpc_unmap_dma_buf(struct dma_buf_attachment *attach,
+				  struct sg_table *table,
+				  enum dma_data_direction dir)
+{
+	dma_unmap_sg(attach->dev, table->sgl, table->nents, dir);
+}
+
+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(sizeof(*a), GFP_KERNEL);
+	if (!a)
+		return -ENOMEM;
+
+	ret = dma_get_sgtable(buffer->dev, &a->sgt, buffer->virt,
+			      FASTRPC_PHYS(buffer->phys), buffer->size);
+	if (ret < 0) {
+		dev_err(buffer->dev, "failed to get scatterlist from DMA API\n");
+		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);
+	kfree(a);
+}
+
+static void *fastrpc_kmap(struct dma_buf *dmabuf, unsigned long pgnum)
+{
+	struct fastrpc_buf *buf = dmabuf->priv;
+
+	return buf->virt ? buf->virt + pgnum * PAGE_SIZE : NULL;
+}
+
+static void *fastrpc_vmap(struct dma_buf *dmabuf)
+{
+	struct fastrpc_buf *buf = dmabuf->priv;
+
+	return buf->virt;
+}
+
+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;
+
+	return dma_mmap_coherent(buf->dev, vma, buf->virt,
+				 FASTRPC_PHYS(buf->phys), 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,
+	.map = fastrpc_kmap,
+	.vmap = fastrpc_vmap,
+	.release = fastrpc_release,
+};
+
+static int fastrpc_map_create(struct fastrpc_user *fl, int fd,
+			      u64 len, struct fastrpc_map **ppmap)
+{
+	struct fastrpc_session_ctx *sess = fl->sctx;
+	struct fastrpc_map *map = NULL;
+	int err = 0;
+
+	if (!fastrpc_map_find(fl, fd, ppmap))
+		return 0;
+
+	map = kzalloc(sizeof(*map), GFP_KERNEL);
+	if (!map)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&map->node);
+	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;
+	}
+
+	map->table = dma_buf_map_attachment(map->attach, DMA_BIDIRECTIONAL);
+	if (IS_ERR(map->table)) {
+		err = PTR_ERR(map->table);
+		goto map_err;
+	}
+
+	map->phys = sg_dma_address(map->table->sgl);
+	map->phys += ((u64)fl->sctx->sid << 32);
+	map->size = len;
+	map->va = sg_virt(map->table->sgl);
+	map->len = len;
+	kref_init(&map->refcount);
+
+	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:
+	kfree(map);
+
+	return err;
+}
+
+/*
+ * Fastrpc payload buffer with metadata looks like:
+ *
+ * >>>>>>  START of METADATA <<<<<<<<<
+ * +---------------------------------+
+ * |           Arguments             |
+ * | type:(struct 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_arg) +
+		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 i;
+
+	size = ALIGN(metalen, FASTRPC_ALIGN);
+	for (i = 0; i < ctx->nscalars; i++) {
+		if (ctx->args[i].fd == 0 || ctx->args[i].fd == -1) {
+			size = ALIGN(size, FASTRPC_ALIGN);
+			size += ctx->args[i].length;
+		}
+	}
+
+	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) {
+		/* Make sure reserved field is set to 0 */
+		if (ctx->args[i].reserved)
+			return -EINVAL;
+
+		if (ctx->args[i].fd == 0 || ctx->args[i].fd == -1 ||
+		    ctx->args[i].length == 0)
+			continue;
+
+		err = fastrpc_map_create(ctx->fl, ctx->args[i].fd,
+					 ctx->args[i].length, &ctx->maps[i]);
+		if (err) {
+			dev_err(dev, "Error Creating map %d\n", err);
+			return -EINVAL;
+		}
+
+	}
+	return 0;
+}
+
+static int fastrpc_get_args(u32 kernel, struct fastrpc_invoke_ctx *ctx)
+{
+	struct device *dev = ctx->fl->sctx->dev;
+	struct fastrpc_remote_arg *rpra;
+	struct fastrpc_invoke_buf *list;
+	struct fastrpc_phy_page *pages;
+	int inbufs, i, err = 0;
+	u64 rlen, pkt_size;
+	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;
+
+	err = fastrpc_buf_alloc(ctx->fl, dev, pkt_size, &ctx->buf);
+	if (err)
+		return err;
+
+	rpra = ctx->buf->virt;
+	list = ctx->buf->virt + ctx->nscalars * sizeof(*rpra);
+	pages = ctx->buf->virt + ctx->nscalars * (sizeof(*list) +
+		sizeof(*rpra));
+	args = (uintptr_t)ctx->buf->virt + metalen;
+	rlen = pkt_size - metalen;
+	ctx->rpra = rpra;
+
+	for (i = 0; i < ctx->nbufs; ++i) {
+		u64 len = ctx->args[i].length;
+
+		rpra[i].pv = 0;
+		rpra[i].len = len;
+		list[i].num = len ? 1 : 0;
+		list[i].pgidx = i;
+
+		if (!len)
+			continue;
+
+		pages[i].size = roundup(len, PAGE_SIZE);
+
+		if (ctx->maps[i]) {
+			rpra[i].pv = (u64) ctx->args[i].ptr;
+			pages[i].addr = ctx->maps[i]->phys;
+		} else {
+			rlen -= ALIGN(args, FASTRPC_ALIGN) - args;
+			args = ALIGN(args, FASTRPC_ALIGN);
+			if (rlen < len)
+				goto bail;
+
+			rpra[i].pv = args;
+			pages[i].addr = ctx->buf->phys + (pkt_size - rlen);
+			pages[i].addr = pages[i].addr &	PAGE_MASK;
+			args = args + len;
+			rlen -= len;
+		}
+
+		if (i < inbufs && !ctx->maps[i]) {
+			void *dst = (void *)(uintptr_t)rpra[i].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) {
+		rpra[i].pv = (u64) ctx->args[i].ptr;
+		rpra[i].len = ctx->args[i].length;
+		list[i].num = ctx->args[i].length ? 1 : 0;
+		list[i].pgidx = i;
+		pages[i].addr = ctx->maps[i]->phys;
+		pages[i].size = ctx->maps[i]->size;
+	}
+
+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)
+{
+	struct fastrpc_remote_arg *rpra = ctx->rpra;
+	int i, inbufs;
+
+	inbufs = REMOTE_SCALARS_INBUFS(ctx->sc);
+
+	for (i = inbufs; i < ctx->nbufs; ++i) {
+		void *src = (void *)(uintptr_t)rpra[i].pv;
+		void *dst = (void *)(uintptr_t)ctx->args[i].ptr;
+		u64 len = rpra[i].len;
+
+		if (!kernel) {
+			if (copy_to_user((void __user *)dst, src, len))
+				return -EFAULT;
+		} else {
+			memcpy(dst, src, len);
+		}
+	}
+
+	return 0;
+}
+
+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;
+
+	cctx = fl->cctx;
+	msg->pid = fl->tgid;
+	msg->tid = current->pid;
+
+	if (kernel)
+		msg->pid = 0;
+
+	msg->ctx = ctx->ctxid | fl->pd;
+	msg->handle = handle;
+	msg->sc = ctx->sc;
+	msg->addr = ctx->buf ? ctx->buf->phys : 0;
+	msg->size = roundup(ctx->msg_sz, PAGE_SIZE);
+	fastrpc_context_get(ctx);
+
+	return rpmsg_send(cctx->rpdev->ept, (void *)msg, sizeof(*msg));
+}
+
+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;
+	int err = 0;
+
+	if (!fl->sctx)
+		return -EINVAL;
+
+	ctx = fastrpc_context_alloc(fl, kernel, sc, args);
+	if (IS_ERR(ctx))
+		return PTR_ERR(ctx);
+
+	if (ctx->nscalars) {
+		err = fastrpc_get_args(kernel, ctx);
+		if (err)
+			goto bail;
+	}
+	/* Send invoke buffer to remote dsp */
+	err = fastrpc_invoke_send(fl->sctx, ctx, kernel, handle);
+	if (err)
+		goto bail;
+
+	/* Wait for remote dsp to respond or time out */
+	err = wait_for_completion_interruptible(&ctx->work);
+	if (err)
+		goto bail;
+
+	/* Check the response from remote dsp */
+	err = ctx->retval;
+	if (err)
+		goto bail;
+
+	if (ctx->nscalars) {
+		/* populate all the output buffers with results */
+		err = fastrpc_put_args(ctx, kernel);
+		if (err)
+			goto bail;
+	}
+
+bail:
+	/* We are done with this compute context, remove it from pending list */
+	spin_lock(&fl->lock);
+	list_del(&ctx->node);
+	spin_unlock(&fl->lock);
+	fastrpc_context_put(ctx);
+
+	if (err)
+		dev_dbg(fl->sctx->dev, "Error: Invoke Failed %d\n", err);
+
+	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 pgid;
+		u32 namelen;
+		u32 filelen;
+		u32 pageslen;
+		u32 attrs;
+		u32 siglen;
+	} inbuf;
+	u32 sc;
+
+	args = kcalloc(FASTRPC_CREATE_PROCESS_NARGS, sizeof(*args), GFP_KERNEL);
+	if (!args)
+		return -ENOMEM;
+
+	if (copy_from_user(&init, argp, sizeof(init))) {
+		err = -EFAULT;
+		goto bail;
+	}
+
+	if (init.filelen > INIT_FILELEN_MAX) {
+		err = -EINVAL;
+		goto bail;
+	}
+
+	inbuf.pgid = fl->tgid;
+	inbuf.namelen = strlen(current->comm) + 1;
+	inbuf.filelen = init.filelen;
+	inbuf.pageslen = 1;
+	inbuf.attrs = init.attrs;
+	inbuf.siglen = init.siglen;
+	fl->pd = 1;
+
+	if (init.filelen && init.filefd) {
+		err = fastrpc_map_create(fl, init.filefd, init.filelen, &map);
+		if (err)
+			goto bail;
+	}
+
+	memlen = ALIGN(max(INIT_FILELEN_MAX, (int)init.filelen * 4),
+		       1024 * 1024);
+	err = fastrpc_buf_alloc(fl, fl->sctx->dev, memlen,
+				&imem);
+	if (err) {
+		fastrpc_map_put(map);
+		goto bail;
+	}
+
+	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->phys;
+	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, 6, 0);
+
+	err = fastrpc_internal_invoke(fl, true, FASTRPC_INIT_HANDLE,
+				      sc, args);
+
+	if (err) {
+		fastrpc_map_put(map);
+		fastrpc_buf_free(imem);
+	}
+
+bail:
+	kfree(args);
+
+	return err;
+}
+
+static struct fastrpc_session_ctx *fastrpc_session_alloc(
+					struct fastrpc_channel_ctx *cctx)
+{
+	struct fastrpc_session_ctx *session = NULL;
+	int i;
+
+	spin_lock(&cctx->lock);
+	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];
+			break;
+		}
+	}
+	spin_unlock(&cctx->lock);
+
+	return session;
+}
+
+static void fastrpc_session_free(struct fastrpc_channel_ctx *cctx,
+				 struct fastrpc_session_ctx *session)
+{
+	spin_lock(&cctx->lock);
+	session->used = false;
+	spin_unlock(&cctx->lock);
+}
+
+static int fastrpc_release_current_dsp_process(struct fastrpc_user *fl)
+{
+	struct fastrpc_invoke_args args[1];
+	int tgid = 0;
+	u32 sc;
+
+	tgid = fl->tgid;
+	args[0].ptr = (u64)(uintptr_t) &tgid;
+	args[0].length = sizeof(tgid);
+	args[0].fd = -1;
+	args[0].reserved = 0;
+	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;
+
+	fastrpc_release_current_dsp_process(fl);
+
+	spin_lock(&cctx->lock);
+	list_del(&fl->user);
+	spin_unlock(&cctx->lock);
+
+	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) {
+		list_del(&map->node);
+		fastrpc_map_put(map);
+	}
+
+	fastrpc_session_free(cctx, fl->sctx);
+
+	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 = miscdev_to_cctx(filp->private_data);
+	struct fastrpc_user *fl = NULL;
+
+	fl = kzalloc(sizeof(*fl), GFP_KERNEL);
+	if (!fl)
+		return -ENOMEM;
+
+	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->user);
+	fl->tgid = current->tgid;
+	fl->cctx = cctx;
+
+	fl->sctx = fastrpc_session_alloc(cctx);
+	if (!fl->sctx) {
+		dev_err(&cctx->rpdev->dev, "No session available\n");
+		mutex_destroy(&fl->mutex);
+		kfree(fl);
+
+		return -EBUSY;
+	}
+
+	spin_lock(&cctx->lock);
+	list_add_tail(&fl->user, &cctx->users);
+	spin_unlock(&cctx->lock);
+
+	return 0;
+}
+
+static int fastrpc_dmabuf_free(struct fastrpc_user *fl, char __user *argp)
+{
+	struct dma_buf *buf;
+	int info;
+
+	if (copy_from_user(&info, argp, sizeof(info)))
+		return -EFAULT;
+
+	buf = dma_buf_get(info);
+	if (IS_ERR_OR_NULL(buf))
+		return -EINVAL;
+	/*
+	 * one for the last get and other for the ALLOC_DMA_BUFF ioctl
+	 */
+	dma_buf_put(buf);
+	dma_buf_put(buf);
+
+	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))) {
+		dma_buf_put(buf->dmabuf);
+		return -EFAULT;
+	}
+
+	get_dma_buf(buf->dmabuf);
+
+	return 0;
+}
+
+static int fastrpc_init_attach(struct fastrpc_user *fl)
+{
+	struct fastrpc_invoke_args args[1];
+	int tgid = fl->tgid;
+	u32 sc;
+
+	args[0].ptr = (u64)(uintptr_t) &tgid;
+	args[0].length = sizeof(tgid);
+	args[0].fd = -1;
+	args[0].reserved = 0;
+	sc = FASTRPC_SCALARS(FASTRPC_RMID_INIT_ATTACH, 1, 0);
+	fl->pd = 0;
+
+	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 = kcalloc(nscalars, sizeof(*args), GFP_KERNEL);
+		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 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);
+		break;
+	case FASTRPC_IOCTL_INIT_CREATE:
+		err = fastrpc_init_create_process(fl, argp);
+		break;
+	case FASTRPC_IOCTL_FREE_DMA_BUFF:
+		err = fastrpc_dmabuf_free(fl, argp);
+		break;
+	case FASTRPC_IOCTL_ALLOC_DMA_BUFF:
+		err = fastrpc_dmabuf_alloc(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;
+
+	cctx = dev_get_drvdata(dev->parent);
+	if (!cctx)
+		return -EINVAL;
+
+	of_property_read_u32(dev->of_node, "qcom,nsessions", &sessions);
+
+	spin_lock(&cctx->lock);
+	sess = &cctx->session[cctx->sesscount];
+	sess->used = false;
+	sess->valid = true;
+	sess->dev = dev;
+	dev_set_drvdata(dev, sess);
+
+	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));
+		}
+	}
+	cctx->sesscount++;
+	spin_unlock(&cctx->lock);
+	dma_set_mask(dev, DMA_BIT_MASK(32));
+
+	return 0;
+}
+
+static int 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);
+	int i;
+
+	spin_lock(&cctx->lock);
+	for (i = 1; i < FASTRPC_MAX_SESSIONS; i++) {
+		if (cctx->session[i].sid == sess->sid) {
+			cctx->session[i].valid = false;
+			cctx->sesscount--;
+		}
+	}
+	spin_unlock(&cctx->lock);
+
+	return 0;
+}
+
+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_rpmsg_probe(struct rpmsg_device *rpdev)
+{
+	struct device *rdev = &rpdev->dev;
+	struct fastrpc_channel_ctx *data;
+	int i, err, domain_id = -1;
+	const char *domain;
+
+	data = devm_kzalloc(rdev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	err = of_property_read_string(rdev->of_node, "label", &domain);
+	if (err) {
+		dev_info(rdev, "FastRPC Domain not specified in DT\n");
+		return err;
+	}
+
+	for (i = 0; i <= CDSP_DOMAIN_ID; i++) {
+		if (!strcmp(domains[i], domain)) {
+			domain_id = i;
+			break;
+		}
+	}
+
+	if (domain_id < 0) {
+		dev_info(rdev, "FastRPC Invalid Domain ID %d\n", domain_id);
+		return -EINVAL;
+	}
+
+	data->miscdev.minor = MISC_DYNAMIC_MINOR;
+	data->miscdev.name = kasprintf(GFP_KERNEL, "fastrpc-%s",
+				domains[domain_id]);
+	data->miscdev.fops = &fastrpc_fops;
+	err = misc_register(&data->miscdev);
+	if (err)
+		return err;
+
+	dev_set_drvdata(&rpdev->dev, data);
+	dma_set_mask_and_coherent(rdev, DMA_BIT_MASK(32));
+	INIT_LIST_HEAD(&data->users);
+	spin_lock_init(&data->lock);
+	idr_init(&data->ctx_idr);
+	data->domain_id = domain_id;
+	data->rpdev = rpdev;
+
+	return of_platform_populate(rdev->of_node, NULL, NULL, rdev);
+}
+
+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)
+		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_user *user;
+
+	spin_lock(&cctx->lock);
+	list_for_each_entry(user, &cctx->users, user)
+		fastrpc_notify_users(user);
+	spin_unlock(&cctx->lock);
+
+	misc_deregister(&cctx->miscdev);
+	of_platform_depopulate(&rpdev->dev);
+	kfree(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);
+	fastrpc_context_put(ctx);
+
+	return 0;
+}
+
+static const struct of_device_id fastrpc_rpmsg_of_match[] = {
+	{ .compatible = "qcom,fastrpc" },
+	{ },
+};
+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_LICENSE("GPL v2");