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From:   Oleksandr Andrushchenko <andr2000@gmail.com>
To:     xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org,
        dri-devel@lists.freedesktop.org, alsa-devel@alsa-project.org,
        jgross@suse.com, boris.ostrovsky@oracle.com
Cc:     andr2000@gmail.com,
        Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Subject: [Xen-devel][PATCH 2/3] drm/xen-front: Use Xen common shared buffer implementation
Date:   Thu, 22 Nov 2018 12:02:29 +0200
Message-Id: <20181122100230.14976-2-andr2000@gmail.com>
In-Reply-To: <20181122100230.14976-1-andr2000@gmail.com>
References: <20181122100230.14976-1-andr2000@gmail.com>
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From: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>

Use page directory based shared buffer implementation
now available as common code for Xen frontend drivers.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
---
 drivers/gpu/drm/xen/Kconfig               |   1 +
 drivers/gpu/drm/xen/Makefile              |   1 -
 drivers/gpu/drm/xen/xen_drm_front.c       |  60 ++--
 drivers/gpu/drm/xen/xen_drm_front_gem.c   |   1 -
 drivers/gpu/drm/xen/xen_drm_front_shbuf.c | 414 ----------------------
 drivers/gpu/drm/xen/xen_drm_front_shbuf.h |  64 ----
 6 files changed, 30 insertions(+), 511 deletions(-)
 delete mode 100644 drivers/gpu/drm/xen/xen_drm_front_shbuf.c
 delete mode 100644 drivers/gpu/drm/xen/xen_drm_front_shbuf.h

diff --git a/drivers/gpu/drm/xen/Kconfig b/drivers/gpu/drm/xen/Kconfig
index 4cca160782ab..f969d486855d 100644
--- a/drivers/gpu/drm/xen/Kconfig
+++ b/drivers/gpu/drm/xen/Kconfig
@@ -12,6 +12,7 @@ config DRM_XEN_FRONTEND
 	select DRM_KMS_HELPER
 	select VIDEOMODE_HELPERS
 	select XEN_XENBUS_FRONTEND
+	select XEN_FRONT_PGDIR_SHBUF
 	help
 	  Choose this option if you want to enable a para-virtualized
 	  frontend DRM/KMS driver for Xen guest OSes.
diff --git a/drivers/gpu/drm/xen/Makefile b/drivers/gpu/drm/xen/Makefile
index 712afff5ffc3..825905f67faa 100644
--- a/drivers/gpu/drm/xen/Makefile
+++ b/drivers/gpu/drm/xen/Makefile
@@ -4,7 +4,6 @@ drm_xen_front-objs := xen_drm_front.o \
 		      xen_drm_front_kms.o \
 		      xen_drm_front_conn.o \
 		      xen_drm_front_evtchnl.o \
-		      xen_drm_front_shbuf.o \
 		      xen_drm_front_cfg.o \
 		      xen_drm_front_gem.o
 
diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c
index 6b6d5ab82ec3..9597544fecc1 100644
--- a/drivers/gpu/drm/xen/xen_drm_front.c
+++ b/drivers/gpu/drm/xen/xen_drm_front.c
@@ -19,6 +19,7 @@
 #include <xen/xen.h>
 #include <xen/xenbus.h>
 
+#include <xen/xen-front-pgdir-shbuf.h>
 #include <xen/interface/io/displif.h>
 
 #include "xen_drm_front.h"
@@ -26,28 +27,20 @@
 #include "xen_drm_front_evtchnl.h"
 #include "xen_drm_front_gem.h"
 #include "xen_drm_front_kms.h"
-#include "xen_drm_front_shbuf.h"
 
 struct xen_drm_front_dbuf {
 	struct list_head list;
 	u64 dbuf_cookie;
 	u64 fb_cookie;
-	struct xen_drm_front_shbuf *shbuf;
+
+	struct xen_front_pgdir_shbuf shbuf;
 };
 
-static int dbuf_add_to_list(struct xen_drm_front_info *front_info,
-			    struct xen_drm_front_shbuf *shbuf, u64 dbuf_cookie)
+static void dbuf_add_to_list(struct xen_drm_front_info *front_info,
+			     struct xen_drm_front_dbuf *dbuf, u64 dbuf_cookie)
 {
-	struct xen_drm_front_dbuf *dbuf;
-
-	dbuf = kzalloc(sizeof(*dbuf), GFP_KERNEL);
-	if (!dbuf)
-		return -ENOMEM;
-
 	dbuf->dbuf_cookie = dbuf_cookie;
-	dbuf->shbuf = shbuf;
 	list_add(&dbuf->list, &front_info->dbuf_list);
-	return 0;
 }
 
 static struct xen_drm_front_dbuf *dbuf_get(struct list_head *dbuf_list,
@@ -64,11 +57,14 @@ static struct xen_drm_front_dbuf *dbuf_get(struct list_head *dbuf_list,
 
 static void dbuf_flush_fb(struct list_head *dbuf_list, u64 fb_cookie)
 {
+#if IS_ENABLED(CONFIG_X86)
 	struct xen_drm_front_dbuf *buf, *q;
 
 	list_for_each_entry_safe(buf, q, dbuf_list, list)
 		if (buf->fb_cookie == fb_cookie)
-			xen_drm_front_shbuf_flush(buf->shbuf);
+			drm_clflush_pages(buf->shbuf.pages,
+					  buf->shbuf.num_pages);
+#endif
 }
 
 static void dbuf_free(struct list_head *dbuf_list, u64 dbuf_cookie)
@@ -78,8 +74,8 @@ static void dbuf_free(struct list_head *dbuf_list, u64 dbuf_cookie)
 	list_for_each_entry_safe(buf, q, dbuf_list, list)
 		if (buf->dbuf_cookie == dbuf_cookie) {
 			list_del(&buf->list);
-			xen_drm_front_shbuf_unmap(buf->shbuf);
-			xen_drm_front_shbuf_free(buf->shbuf);
+			xen_front_pgdir_shbuf_unmap(&buf->shbuf);
+			xen_front_pgdir_shbuf_free(&buf->shbuf);
 			kfree(buf);
 			break;
 		}
@@ -91,8 +87,8 @@ static void dbuf_free_all(struct list_head *dbuf_list)
 
 	list_for_each_entry_safe(buf, q, dbuf_list, list) {
 		list_del(&buf->list);
-		xen_drm_front_shbuf_unmap(buf->shbuf);
-		xen_drm_front_shbuf_free(buf->shbuf);
+		xen_front_pgdir_shbuf_unmap(&buf->shbuf);
+		xen_front_pgdir_shbuf_free(&buf->shbuf);
 		kfree(buf);
 	}
 }
@@ -171,9 +167,9 @@ int xen_drm_front_dbuf_create(struct xen_drm_front_info *front_info,
 			      u32 bpp, u64 size, struct page **pages)
 {
 	struct xen_drm_front_evtchnl *evtchnl;
-	struct xen_drm_front_shbuf *shbuf;
+	struct xen_drm_front_dbuf *dbuf;
 	struct xendispl_req *req;
-	struct xen_drm_front_shbuf_cfg buf_cfg;
+	struct xen_front_pgdir_shbuf_cfg buf_cfg;
 	unsigned long flags;
 	int ret;
 
@@ -181,28 +177,29 @@ int xen_drm_front_dbuf_create(struct xen_drm_front_info *front_info,
 	if (unlikely(!evtchnl))
 		return -EIO;
 
+	dbuf = kzalloc(sizeof(*dbuf), GFP_KERNEL);
+	if (!dbuf)
+		return -ENOMEM;
+
+	dbuf_add_to_list(front_info, dbuf, dbuf_cookie);
+
 	memset(&buf_cfg, 0, sizeof(buf_cfg));
 	buf_cfg.xb_dev = front_info->xb_dev;
+	buf_cfg.num_pages = DIV_ROUND_UP(size, PAGE_SIZE);
 	buf_cfg.pages = pages;
-	buf_cfg.size = size;
+	buf_cfg.pgdir = &dbuf->shbuf;
 	buf_cfg.be_alloc = front_info->cfg.be_alloc;
 
-	shbuf = xen_drm_front_shbuf_alloc(&buf_cfg);
-	if (IS_ERR(shbuf))
-		return PTR_ERR(shbuf);
-
-	ret = dbuf_add_to_list(front_info, shbuf, dbuf_cookie);
-	if (ret < 0) {
-		xen_drm_front_shbuf_free(shbuf);
-		return ret;
-	}
+	ret = xen_front_pgdir_shbuf_alloc(&buf_cfg);
+	if (ret < 0)
+		goto fail_shbuf_alloc;
 
 	mutex_lock(&evtchnl->u.req.req_io_lock);
 
 	spin_lock_irqsave(&front_info->io_lock, flags);
 	req = be_prepare_req(evtchnl, XENDISPL_OP_DBUF_CREATE);
 	req->op.dbuf_create.gref_directory =
-			xen_drm_front_shbuf_get_dir_start(shbuf);
+			xen_front_pgdir_shbuf_get_dir_start(&dbuf->shbuf);
 	req->op.dbuf_create.buffer_sz = size;
 	req->op.dbuf_create.dbuf_cookie = dbuf_cookie;
 	req->op.dbuf_create.width = width;
@@ -221,7 +218,7 @@ int xen_drm_front_dbuf_create(struct xen_drm_front_info *front_info,
 	if (ret < 0)
 		goto fail;
 
-	ret = xen_drm_front_shbuf_map(shbuf);
+	ret = xen_front_pgdir_shbuf_map(&dbuf->shbuf);
 	if (ret < 0)
 		goto fail;
 
@@ -230,6 +227,7 @@ int xen_drm_front_dbuf_create(struct xen_drm_front_info *front_info,
 
 fail:
 	mutex_unlock(&evtchnl->u.req.req_io_lock);
+fail_shbuf_alloc:
 	dbuf_free(&front_info->dbuf_list, dbuf_cookie);
 	return ret;
 }
diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
index c85bfe7571cb..53be4c7dc0a4 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
@@ -22,7 +22,6 @@
 #include <xen/balloon.h>
 
 #include "xen_drm_front.h"
-#include "xen_drm_front_shbuf.h"
 
 struct xen_gem_object {
 	struct drm_gem_object base;
diff --git a/drivers/gpu/drm/xen/xen_drm_front_shbuf.c b/drivers/gpu/drm/xen/xen_drm_front_shbuf.c
deleted file mode 100644
index d333b67cc1a0..000000000000
--- a/drivers/gpu/drm/xen/xen_drm_front_shbuf.c
+++ /dev/null
@@ -1,414 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0 OR MIT
-
-/*
- *  Xen para-virtual DRM device
- *
- * Copyright (C) 2016-2018 EPAM Systems Inc.
- *
- * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
- */
-
-#include <drm/drmP.h>
-
-#if defined(CONFIG_X86)
-#include <drm/drm_cache.h>
-#endif
-#include <linux/errno.h>
-#include <linux/mm.h>
-
-#include <asm/xen/hypervisor.h>
-#include <xen/balloon.h>
-#include <xen/xen.h>
-#include <xen/xenbus.h>
-#include <xen/interface/io/ring.h>
-#include <xen/interface/io/displif.h>
-
-#include "xen_drm_front.h"
-#include "xen_drm_front_shbuf.h"
-
-struct xen_drm_front_shbuf_ops {
-	/*
-	 * Calculate number of grefs required to handle this buffer,
-	 * e.g. if grefs are required for page directory only or the buffer
-	 * pages as well.
-	 */
-	void (*calc_num_grefs)(struct xen_drm_front_shbuf *buf);
-	/* Fill page directory according to para-virtual display protocol. */
-	void (*fill_page_dir)(struct xen_drm_front_shbuf *buf);
-	/* Claim grant references for the pages of the buffer. */
-	int (*grant_refs_for_buffer)(struct xen_drm_front_shbuf *buf,
-				     grant_ref_t *priv_gref_head, int gref_idx);
-	/* Map grant references of the buffer. */
-	int (*map)(struct xen_drm_front_shbuf *buf);
-	/* Unmap grant references of the buffer. */
-	int (*unmap)(struct xen_drm_front_shbuf *buf);
-};
-
-grant_ref_t xen_drm_front_shbuf_get_dir_start(struct xen_drm_front_shbuf *buf)
-{
-	if (!buf->grefs)
-		return GRANT_INVALID_REF;
-
-	return buf->grefs[0];
-}
-
-int xen_drm_front_shbuf_map(struct xen_drm_front_shbuf *buf)
-{
-	if (buf->ops->map)
-		return buf->ops->map(buf);
-
-	/* no need to map own grant references */
-	return 0;
-}
-
-int xen_drm_front_shbuf_unmap(struct xen_drm_front_shbuf *buf)
-{
-	if (buf->ops->unmap)
-		return buf->ops->unmap(buf);
-
-	/* no need to unmap own grant references */
-	return 0;
-}
-
-void xen_drm_front_shbuf_flush(struct xen_drm_front_shbuf *buf)
-{
-#if defined(CONFIG_X86)
-	drm_clflush_pages(buf->pages, buf->num_pages);
-#endif
-}
-
-void xen_drm_front_shbuf_free(struct xen_drm_front_shbuf *buf)
-{
-	if (buf->grefs) {
-		int i;
-
-		for (i = 0; i < buf->num_grefs; i++)
-			if (buf->grefs[i] != GRANT_INVALID_REF)
-				gnttab_end_foreign_access(buf->grefs[i],
-							  0, 0UL);
-	}
-	kfree(buf->grefs);
-	kfree(buf->directory);
-	kfree(buf);
-}
-
-/*
- * number of grefs a page can hold with respect to the
- * struct xendispl_page_directory header
- */
-#define XEN_DRM_NUM_GREFS_PER_PAGE ((PAGE_SIZE - \
-		offsetof(struct xendispl_page_directory, gref)) / \
-		sizeof(grant_ref_t))
-
-static int get_num_pages_dir(struct xen_drm_front_shbuf *buf)
-{
-	/* number of pages the page directory consumes itself */
-	return DIV_ROUND_UP(buf->num_pages, XEN_DRM_NUM_GREFS_PER_PAGE);
-}
-
-static void backend_calc_num_grefs(struct xen_drm_front_shbuf *buf)
-{
-	/* only for pages the page directory consumes itself */
-	buf->num_grefs = get_num_pages_dir(buf);
-}
-
-static void guest_calc_num_grefs(struct xen_drm_front_shbuf *buf)
-{
-	/*
-	 * number of pages the page directory consumes itself
-	 * plus grefs for the buffer pages
-	 */
-	buf->num_grefs = get_num_pages_dir(buf) + buf->num_pages;
-}
-
-#define xen_page_to_vaddr(page) \
-		((uintptr_t)pfn_to_kaddr(page_to_xen_pfn(page)))
-
-static int backend_unmap(struct xen_drm_front_shbuf *buf)
-{
-	struct gnttab_unmap_grant_ref *unmap_ops;
-	int i, ret;
-
-	if (!buf->pages || !buf->backend_map_handles || !buf->grefs)
-		return 0;
-
-	unmap_ops = kcalloc(buf->num_pages, sizeof(*unmap_ops),
-			    GFP_KERNEL);
-	if (!unmap_ops) {
-		DRM_ERROR("Failed to get memory while unmapping\n");
-		return -ENOMEM;
-	}
-
-	for (i = 0; i < buf->num_pages; i++) {
-		phys_addr_t addr;
-
-		addr = xen_page_to_vaddr(buf->pages[i]);
-		gnttab_set_unmap_op(&unmap_ops[i], addr, GNTMAP_host_map,
-				    buf->backend_map_handles[i]);
-	}
-
-	ret = gnttab_unmap_refs(unmap_ops, NULL, buf->pages,
-				buf->num_pages);
-
-	for (i = 0; i < buf->num_pages; i++) {
-		if (unlikely(unmap_ops[i].status != GNTST_okay))
-			DRM_ERROR("Failed to unmap page %d: %d\n",
-				  i, unmap_ops[i].status);
-	}
-
-	if (ret)
-		DRM_ERROR("Failed to unmap grant references, ret %d", ret);
-
-	kfree(unmap_ops);
-	kfree(buf->backend_map_handles);
-	buf->backend_map_handles = NULL;
-	return ret;
-}
-
-static int backend_map(struct xen_drm_front_shbuf *buf)
-{
-	struct gnttab_map_grant_ref *map_ops = NULL;
-	unsigned char *ptr;
-	int ret, cur_gref, cur_dir_page, cur_page, grefs_left;
-
-	map_ops = kcalloc(buf->num_pages, sizeof(*map_ops), GFP_KERNEL);
-	if (!map_ops)
-		return -ENOMEM;
-
-	buf->backend_map_handles = kcalloc(buf->num_pages,
-					   sizeof(*buf->backend_map_handles),
-					   GFP_KERNEL);
-	if (!buf->backend_map_handles) {
-		kfree(map_ops);
-		return -ENOMEM;
-	}
-
-	/*
-	 * read page directory to get grefs from the backend: for external
-	 * buffer we only allocate buf->grefs for the page directory,
-	 * so buf->num_grefs has number of pages in the page directory itself
-	 */
-	ptr = buf->directory;
-	grefs_left = buf->num_pages;
-	cur_page = 0;
-	for (cur_dir_page = 0; cur_dir_page < buf->num_grefs; cur_dir_page++) {
-		struct xendispl_page_directory *page_dir =
-				(struct xendispl_page_directory *)ptr;
-		int to_copy = XEN_DRM_NUM_GREFS_PER_PAGE;
-
-		if (to_copy > grefs_left)
-			to_copy = grefs_left;
-
-		for (cur_gref = 0; cur_gref < to_copy; cur_gref++) {
-			phys_addr_t addr;
-
-			addr = xen_page_to_vaddr(buf->pages[cur_page]);
-			gnttab_set_map_op(&map_ops[cur_page], addr,
-					  GNTMAP_host_map,
-					  page_dir->gref[cur_gref],
-					  buf->xb_dev->otherend_id);
-			cur_page++;
-		}
-
-		grefs_left -= to_copy;
-		ptr += PAGE_SIZE;
-	}
-	ret = gnttab_map_refs(map_ops, NULL, buf->pages, buf->num_pages);
-
-	/* save handles even if error, so we can unmap */
-	for (cur_page = 0; cur_page < buf->num_pages; cur_page++) {
-		buf->backend_map_handles[cur_page] = map_ops[cur_page].handle;
-		if (unlikely(map_ops[cur_page].status != GNTST_okay))
-			DRM_ERROR("Failed to map page %d: %d\n",
-				  cur_page, map_ops[cur_page].status);
-	}
-
-	if (ret) {
-		DRM_ERROR("Failed to map grant references, ret %d", ret);
-		backend_unmap(buf);
-	}
-
-	kfree(map_ops);
-	return ret;
-}
-
-static void backend_fill_page_dir(struct xen_drm_front_shbuf *buf)
-{
-	struct xendispl_page_directory *page_dir;
-	unsigned char *ptr;
-	int i, num_pages_dir;
-
-	ptr = buf->directory;
-	num_pages_dir = get_num_pages_dir(buf);
-
-	/* fill only grefs for the page directory itself */
-	for (i = 0; i < num_pages_dir - 1; i++) {
-		page_dir = (struct xendispl_page_directory *)ptr;
-
-		page_dir->gref_dir_next_page = buf->grefs[i + 1];
-		ptr += PAGE_SIZE;
-	}
-	/* last page must say there is no more pages */
-	page_dir = (struct xendispl_page_directory *)ptr;
-	page_dir->gref_dir_next_page = GRANT_INVALID_REF;
-}
-
-static void guest_fill_page_dir(struct xen_drm_front_shbuf *buf)
-{
-	unsigned char *ptr;
-	int cur_gref, grefs_left, to_copy, i, num_pages_dir;
-
-	ptr = buf->directory;
-	num_pages_dir = get_num_pages_dir(buf);
-
-	/*
-	 * while copying, skip grefs at start, they are for pages
-	 * granted for the page directory itself
-	 */
-	cur_gref = num_pages_dir;
-	grefs_left = buf->num_pages;
-	for (i = 0; i < num_pages_dir; i++) {
-		struct xendispl_page_directory *page_dir =
-				(struct xendispl_page_directory *)ptr;
-
-		if (grefs_left <= XEN_DRM_NUM_GREFS_PER_PAGE) {
-			to_copy = grefs_left;
-			page_dir->gref_dir_next_page = GRANT_INVALID_REF;
-		} else {
-			to_copy = XEN_DRM_NUM_GREFS_PER_PAGE;
-			page_dir->gref_dir_next_page = buf->grefs[i + 1];
-		}
-		memcpy(&page_dir->gref, &buf->grefs[cur_gref],
-		       to_copy * sizeof(grant_ref_t));
-		ptr += PAGE_SIZE;
-		grefs_left -= to_copy;
-		cur_gref += to_copy;
-	}
-}
-
-static int guest_grant_refs_for_buffer(struct xen_drm_front_shbuf *buf,
-				       grant_ref_t *priv_gref_head,
-				       int gref_idx)
-{
-	int i, cur_ref, otherend_id;
-
-	otherend_id = buf->xb_dev->otherend_id;
-	for (i = 0; i < buf->num_pages; i++) {
-		cur_ref = gnttab_claim_grant_reference(priv_gref_head);
-		if (cur_ref < 0)
-			return cur_ref;
-
-		gnttab_grant_foreign_access_ref(cur_ref, otherend_id,
-						xen_page_to_gfn(buf->pages[i]),
-						0);
-		buf->grefs[gref_idx++] = cur_ref;
-	}
-	return 0;
-}
-
-static int grant_references(struct xen_drm_front_shbuf *buf)
-{
-	grant_ref_t priv_gref_head;
-	int ret, i, j, cur_ref;
-	int otherend_id, num_pages_dir;
-
-	ret = gnttab_alloc_grant_references(buf->num_grefs, &priv_gref_head);
-	if (ret < 0) {
-		DRM_ERROR("Cannot allocate grant references\n");
-		return ret;
-	}
-
-	otherend_id = buf->xb_dev->otherend_id;
-	j = 0;
-	num_pages_dir = get_num_pages_dir(buf);
-	for (i = 0; i < num_pages_dir; i++) {
-		unsigned long frame;
-
-		cur_ref = gnttab_claim_grant_reference(&priv_gref_head);
-		if (cur_ref < 0)
-			return cur_ref;
-
-		frame = xen_page_to_gfn(virt_to_page(buf->directory +
-					PAGE_SIZE * i));
-		gnttab_grant_foreign_access_ref(cur_ref, otherend_id, frame, 0);
-		buf->grefs[j++] = cur_ref;
-	}
-
-	if (buf->ops->grant_refs_for_buffer) {
-		ret = buf->ops->grant_refs_for_buffer(buf, &priv_gref_head, j);
-		if (ret)
-			return ret;
-	}
-
-	gnttab_free_grant_references(priv_gref_head);
-	return 0;
-}
-
-static int alloc_storage(struct xen_drm_front_shbuf *buf)
-{
-	buf->grefs = kcalloc(buf->num_grefs, sizeof(*buf->grefs), GFP_KERNEL);
-	if (!buf->grefs)
-		return -ENOMEM;
-
-	buf->directory = kcalloc(get_num_pages_dir(buf), PAGE_SIZE, GFP_KERNEL);
-	if (!buf->directory)
-		return -ENOMEM;
-
-	return 0;
-}
-
-/*
- * For be allocated buffers we don't need grant_refs_for_buffer as those
- * grant references are allocated at backend side
- */
-static const struct xen_drm_front_shbuf_ops backend_ops = {
-	.calc_num_grefs = backend_calc_num_grefs,
-	.fill_page_dir = backend_fill_page_dir,
-	.map = backend_map,
-	.unmap = backend_unmap
-};
-
-/* For locally granted references we do not need to map/unmap the references */
-static const struct xen_drm_front_shbuf_ops local_ops = {
-	.calc_num_grefs = guest_calc_num_grefs,
-	.fill_page_dir = guest_fill_page_dir,
-	.grant_refs_for_buffer = guest_grant_refs_for_buffer,
-};
-
-struct xen_drm_front_shbuf *
-xen_drm_front_shbuf_alloc(struct xen_drm_front_shbuf_cfg *cfg)
-{
-	struct xen_drm_front_shbuf *buf;
-	int ret;
-
-	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
-	if (!buf)
-		return ERR_PTR(-ENOMEM);
-
-	if (cfg->be_alloc)
-		buf->ops = &backend_ops;
-	else
-		buf->ops = &local_ops;
-
-	buf->xb_dev = cfg->xb_dev;
-	buf->num_pages = DIV_ROUND_UP(cfg->size, PAGE_SIZE);
-	buf->pages = cfg->pages;
-
-	buf->ops->calc_num_grefs(buf);
-
-	ret = alloc_storage(buf);
-	if (ret)
-		goto fail;
-
-	ret = grant_references(buf);
-	if (ret)
-		goto fail;
-
-	buf->ops->fill_page_dir(buf);
-
-	return buf;
-
-fail:
-	xen_drm_front_shbuf_free(buf);
-	return ERR_PTR(ret);
-}
diff --git a/drivers/gpu/drm/xen/xen_drm_front_shbuf.h b/drivers/gpu/drm/xen/xen_drm_front_shbuf.h
deleted file mode 100644
index 7545c692539e..000000000000
--- a/drivers/gpu/drm/xen/xen_drm_front_shbuf.h
+++ /dev/null
@@ -1,64 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 OR MIT */
-
-/*
- *  Xen para-virtual DRM device
- *
- * Copyright (C) 2016-2018 EPAM Systems Inc.
- *
- * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
- */
-
-#ifndef __XEN_DRM_FRONT_SHBUF_H_
-#define __XEN_DRM_FRONT_SHBUF_H_
-
-#include <linux/kernel.h>
-#include <linux/scatterlist.h>
-
-#include <xen/grant_table.h>
-
-struct xen_drm_front_shbuf {
-	/*
-	 * number of references granted for the backend use:
-	 *  - for allocated/imported dma-buf's this holds number of grant
-	 *    references for the page directory and pages of the buffer
-	 *  - for the buffer provided by the backend this holds number of
-	 *    grant references for the page directory as grant references for
-	 *    the buffer will be provided by the backend
-	 */
-	int num_grefs;
-	grant_ref_t *grefs;
-	unsigned char *directory;
-
-	int num_pages;
-	struct page **pages;
-
-	struct xenbus_device *xb_dev;
-
-	/* these are the ops used internally depending on be_alloc mode */
-	const struct xen_drm_front_shbuf_ops *ops;
-
-	/* Xen map handles for the buffer allocated by the backend */
-	grant_handle_t *backend_map_handles;
-};
-
-struct xen_drm_front_shbuf_cfg {
-	struct xenbus_device *xb_dev;
-	size_t size;
-	struct page **pages;
-	bool be_alloc;
-};
-
-struct xen_drm_front_shbuf *
-xen_drm_front_shbuf_alloc(struct xen_drm_front_shbuf_cfg *cfg);
-
-grant_ref_t xen_drm_front_shbuf_get_dir_start(struct xen_drm_front_shbuf *buf);
-
-int xen_drm_front_shbuf_map(struct xen_drm_front_shbuf *buf);
-
-int xen_drm_front_shbuf_unmap(struct xen_drm_front_shbuf *buf);
-
-void xen_drm_front_shbuf_flush(struct xen_drm_front_shbuf *buf);
-
-void xen_drm_front_shbuf_free(struct xen_drm_front_shbuf *buf);
-
-#endif /* __XEN_DRM_FRONT_SHBUF_H_ */
-- 
2.19.1