[Xen-devel][PATCH 2/3] drm/xen-front: Use Xen common shared buffer implementation

From: Oleksandr Andrushchenko
Date: Thu Nov 22 2018 - 05:02:52 EST

From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>

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

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
---
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@xxxxxxxx>
- */
-
-#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@xxxxxxxx>
- */
-
-#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