[Xen-devel][PATCH v2 2/3] drm/xen-front: Use Xen common shared buffer implementation
Oleksandr Andrushchenko
andr2000 at gmail.com
Mon Dec 17 10:19:23 UTC 2018
Hello, Juergen, Boris!
As this DRM part of the series is the only one which needs ack/nack
(and it might take quite some time to complete) could we please
merge the patches 1 and 3 now that already have ack/r-b?
Thank you,
Oleksandr
On 12/13/18 12:16 PM, Oleksandr Andrushchenko wrote:
> bump
>
> On 12/5/18 10:20 AM, Oleksandr Andrushchenko wrote:
>> Hello, Daniel!
>>
>> Could you please ack/nack the patch, so either we can merge the
>>
>> series or I can address your comments if any
>>
>> Thank you,
>>
>> Oleksandr
>>
>> On 11/30/18 9:42 AM, Oleksandr Andrushchenko wrote:
>>> From: Oleksandr Andrushchenko <oleksandr_andrushchenko at epam.com>
>>>
>>> Use page directory based shared buffer implementation
>>> now available as common code for Xen frontend drivers.
>>>
>>> Remove flushing of shared buffer on page flip as this
>>> workaround needs a proper fix.
>>>
>>> Signed-off-by: Oleksandr Andrushchenko
>>> <oleksandr_andrushchenko at epam.com>
>>> ---
>>> drivers/gpu/drm/xen/Kconfig | 1 +
>>> drivers/gpu/drm/xen/Makefile | 1 -
>>> drivers/gpu/drm/xen/xen_drm_front.c | 65 ++--
>>> 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, 26 insertions(+), 520 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..4d3d36fc3a5d 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,
>>> @@ -62,15 +55,6 @@ static struct xen_drm_front_dbuf *dbuf_get(struct
>>> list_head *dbuf_list,
>>> return NULL;
>>> }
>>> -static void dbuf_flush_fb(struct list_head *dbuf_list, u64
>>> fb_cookie)
>>> -{
>>> - 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);
>>> -}
>>> -
>>> static void dbuf_free(struct list_head *dbuf_list, u64 dbuf_cookie)
>>> {
>>> struct xen_drm_front_dbuf *buf, *q;
>>> @@ -78,8 +62,8 @@ 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 +75,8 @@ 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 +155,9 @@ 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 +165,29 @@ 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 +206,7 @@ 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 +215,7 @@ 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;
>>> }
>>> @@ -358,7 +344,6 @@ int xen_drm_front_page_flip(struct
>>> xen_drm_front_info *front_info,
>>> if (unlikely(conn_idx >= front_info->num_evt_pairs))
>>> return -EINVAL;
>>> - dbuf_flush_fb(&front_info->dbuf_list, fb_cookie);
>>> evtchnl = &front_info->evt_pairs[conn_idx].req;
>>> mutex_lock(&evtchnl->u.req.req_io_lock);
>>> 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 at 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 at 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_ */
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