drm/xen-front: Use Xen common shared buffer implementation (5641f19b) · Commits · EulixOS / Software / Kernel

drivers/gpu/drm/xen/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -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.

drivers/gpu/drm/xen/Makefile

+0 −1

Original line number	Diff line number	Diff line
		@@ -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

drivers/gpu/drm/xen/xen_drm_front.c

+25 −40

Original line number	Diff line number	Diff line
		@@ -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);

drivers/gpu/drm/xen/xen_drm_front_gem.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -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;

drivers/gpu/drm/xen/xen_drm_front_shbuf.c

deleted100644 → 0

+0 −414

Original line number	Diff line number	Diff line
		// 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);
		}