From: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com

Introduce skeleton of the para-virtualized Xen display frontend driver. This patch only adds required essential stubs.

Signed-off-by: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com --- drivers/gpu/drm/Kconfig | 2 ++ drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/xen/Kconfig | 17 +++++++++ drivers/gpu/drm/xen/Makefile | 5 +++ drivers/gpu/drm/xen/xen_drm_front.c | 70 +++++++++++++++++++++++++++++++++++++ 5 files changed, 95 insertions(+) create mode 100644 drivers/gpu/drm/xen/Kconfig create mode 100644 drivers/gpu/drm/xen/Makefile create mode 100644 drivers/gpu/drm/xen/xen_drm_front.c

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index deeefa7a1773..757825ac60df 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -289,6 +289,8 @@ source "drivers/gpu/drm/pl111/Kconfig"

source "drivers/gpu/drm/tve200/Kconfig"

+source "drivers/gpu/drm/xen/Kconfig" + # Keep legacy drivers last

menuconfig DRM_LEGACY diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 50093ff4479b..9d66657ea117 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -103,3 +103,4 @@ obj-$(CONFIG_DRM_MXSFB) += mxsfb/ obj-$(CONFIG_DRM_TINYDRM) += tinydrm/ obj-$(CONFIG_DRM_PL111) += pl111/ obj-$(CONFIG_DRM_TVE200) += tve200/ +obj-$(CONFIG_DRM_XEN) += xen/ diff --git a/drivers/gpu/drm/xen/Kconfig b/drivers/gpu/drm/xen/Kconfig new file mode 100644 index 000000000000..4cca160782ab --- /dev/null +++ b/drivers/gpu/drm/xen/Kconfig @@ -0,0 +1,17 @@ +config DRM_XEN + bool "DRM Support for Xen guest OS" + depends on XEN + help + Choose this option if you want to enable DRM support + for Xen. + +config DRM_XEN_FRONTEND + tristate "Para-virtualized frontend driver for Xen guest OS" + depends on DRM_XEN + depends on DRM + select DRM_KMS_HELPER + select VIDEOMODE_HELPERS + select XEN_XENBUS_FRONTEND + help + Choose this option if you want to enable a para-virtualized + frontend DRM/KMS driver for Xen guest OSes. diff --git a/drivers/gpu/drm/xen/Makefile b/drivers/gpu/drm/xen/Makefile new file mode 100644 index 000000000000..3283e104c7bb --- /dev/null +++ b/drivers/gpu/drm/xen/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0 OR MIT + +drm_xen_front-objs := xen_drm_front.o + +obj-$(CONFIG_DRM_XEN_FRONTEND) += drm_xen_front.o diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c new file mode 100644 index 000000000000..03bc50b128fd --- /dev/null +++ b/drivers/gpu/drm/xen/xen_drm_front.c @@ -0,0 +1,70 @@ +// 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> + +#include <xen/platform_pci.h> +#include <xen/xen.h> +#include <xen/xenbus.h> + +#include <xen/interface/io/displif.h> + +static void displback_changed(struct xenbus_device *xb_dev, + enum xenbus_state backend_state) +{ +} + +static int xen_drv_probe(struct xenbus_device *xb_dev, + const struct xenbus_device_id *id) +{ + return 0; +} + +static int xen_drv_remove(struct xenbus_device *dev) +{ + return 0; +} + +static const struct xenbus_device_id xen_drv_ids[] = { + { XENDISPL_DRIVER_NAME }, + { "" } +}; + +static struct xenbus_driver xen_driver = { + .ids = xen_drv_ids, + .probe = xen_drv_probe, + .remove = xen_drv_remove, + .otherend_changed = displback_changed, +}; + +static int __init xen_drv_init(void) +{ + if (!xen_domain()) + return -ENODEV; + + if (!xen_has_pv_devices()) + return -ENODEV; + + DRM_INFO("Registering XEN PV " XENDISPL_DRIVER_NAME "\n"); + return xenbus_register_frontend(&xen_driver); +} + +static void __exit xen_drv_cleanup(void) +{ + DRM_INFO("Unregistering XEN PV " XENDISPL_DRIVER_NAME "\n"); + xenbus_unregister_driver(&xen_driver); +} + +module_init(xen_drv_init); +module_exit(xen_drv_cleanup); + +MODULE_DESCRIPTION("Xen para-virtualized display device frontend"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("xen:"XENDISPL_DRIVER_NAME);

From: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com

Read configuration values from Xen store according to xen/interface/io/displif.h protocol: - read connector(s) configuration - read buffer allocation mode (backend/frontend)

Signed-off-by: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com --- drivers/gpu/drm/xen/Makefile | 3 +- drivers/gpu/drm/xen/xen_drm_front.c | 9 ++++ drivers/gpu/drm/xen/xen_drm_front.h | 3 ++ drivers/gpu/drm/xen/xen_drm_front_cfg.c | 77 +++++++++++++++++++++++++++++++++ drivers/gpu/drm/xen/xen_drm_front_cfg.h | 37 ++++++++++++++++ 5 files changed, 128 insertions(+), 1 deletion(-) create mode 100644 drivers/gpu/drm/xen/xen_drm_front_cfg.c create mode 100644 drivers/gpu/drm/xen/xen_drm_front_cfg.h

diff --git a/drivers/gpu/drm/xen/Makefile b/drivers/gpu/drm/xen/Makefile index 3283e104c7bb..d3ec8c8589e0 100644 --- a/drivers/gpu/drm/xen/Makefile +++ b/drivers/gpu/drm/xen/Makefile @@ -1,5 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 OR MIT

-drm_xen_front-objs := xen_drm_front.o +drm_xen_front-objs := xen_drm_front.o \ + xen_drm_front_cfg.o

obj-$(CONFIG_DRM_XEN_FRONTEND) += drm_xen_front.o diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c index 520b5b34520b..ca42ceb24a40 100644 --- a/drivers/gpu/drm/xen/xen_drm_front.c +++ b/drivers/gpu/drm/xen/xen_drm_front.c @@ -24,6 +24,15 @@ static void xen_drv_remove_internal(struct xen_drm_front_info *front_info)

static int displback_initwait(struct xen_drm_front_info *front_info) { + struct xen_drm_front_cfg *cfg = &front_info->cfg; + int ret; + + cfg->front_info = front_info; + ret = xen_drm_front_cfg_card(front_info, cfg); + if (ret < 0) + return ret; + + DRM_INFO("Have %d conector(s)\n", cfg->num_connectors); return 0; }

diff --git a/drivers/gpu/drm/xen/xen_drm_front.h b/drivers/gpu/drm/xen/xen_drm_front.h index 8b8d4d1e0816..034a3987657e 100644 --- a/drivers/gpu/drm/xen/xen_drm_front.h +++ b/drivers/gpu/drm/xen/xen_drm_front.h @@ -11,8 +11,11 @@ #ifndef __XEN_DRM_FRONT_H_ #define __XEN_DRM_FRONT_H_

+#include "xen_drm_front_cfg.h" + struct xen_drm_front_info { struct xenbus_device *xb_dev; + struct xen_drm_front_cfg cfg; };

#endif /* __XEN_DRM_FRONT_H_ */ diff --git a/drivers/gpu/drm/xen/xen_drm_front_cfg.c b/drivers/gpu/drm/xen/xen_drm_front_cfg.c new file mode 100644 index 000000000000..9a0b2b8e6169 --- /dev/null +++ b/drivers/gpu/drm/xen/xen_drm_front_cfg.c @@ -0,0 +1,77 @@ +// 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> + +#include <linux/device.h> + +#include <xen/interface/io/displif.h> +#include <xen/xenbus.h> + +#include "xen_drm_front.h" +#include "xen_drm_front_cfg.h" + +static int cfg_connector(struct xen_drm_front_info *front_info, + struct xen_drm_front_cfg_connector *connector, + const char *path, int index) +{ + char *connector_path; + + connector_path = devm_kasprintf(&front_info->xb_dev->dev, + GFP_KERNEL, "%s/%d", path, index); + if (!connector_path) + return -ENOMEM; + + if (xenbus_scanf(XBT_NIL, connector_path, XENDISPL_FIELD_RESOLUTION, + "%d" XENDISPL_RESOLUTION_SEPARATOR "%d", + &connector->width, &connector->height) < 0) { + /* either no entry configured or wrong resolution set */ + connector->width = 0; + connector->height = 0; + return -EINVAL; + } + + connector->xenstore_path = connector_path; + + DRM_INFO("Connector %s: resolution %dx%d\n", + connector_path, connector->width, connector->height); + return 0; +} + +int xen_drm_front_cfg_card(struct xen_drm_front_info *front_info, + struct xen_drm_front_cfg *cfg) +{ + struct xenbus_device *xb_dev = front_info->xb_dev; + int ret, i; + + if (xenbus_read_unsigned(front_info->xb_dev->nodename, + XENDISPL_FIELD_BE_ALLOC, 0)) { + DRM_INFO("Backend can provide display buffers\n"); + cfg->be_alloc = true; + } + + cfg->num_connectors = 0; + for (i = 0; i < ARRAY_SIZE(cfg->connectors); i++) { + ret = cfg_connector(front_info, + &cfg->connectors[i], xb_dev->nodename, i); + if (ret < 0) + break; + cfg->num_connectors++; + } + + if (!cfg->num_connectors) { + DRM_ERROR("No connector(s) configured at %s\n", + xb_dev->nodename); + return -ENODEV; + } + + return 0; +} + diff --git a/drivers/gpu/drm/xen/xen_drm_front_cfg.h b/drivers/gpu/drm/xen/xen_drm_front_cfg.h new file mode 100644 index 000000000000..6e7af670f8cd --- /dev/null +++ b/drivers/gpu/drm/xen/xen_drm_front_cfg.h @@ -0,0 +1,37 @@ +/* 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_CFG_H_ +#define __XEN_DRM_FRONT_CFG_H_ + +#include <linux/types.h> + +#define XEN_DRM_FRONT_MAX_CRTCS 4 + +struct xen_drm_front_cfg_connector { + int width; + int height; + char *xenstore_path; +}; + +struct xen_drm_front_cfg { + struct xen_drm_front_info *front_info; + /* number of connectors in this configuration */ + int num_connectors; + /* connector configurations */ + struct xen_drm_front_cfg_connector connectors[XEN_DRM_FRONT_MAX_CRTCS]; + /* set if dumb buffers are allocated externally on backend side */ + bool be_alloc; +}; + +int xen_drm_front_cfg_card(struct xen_drm_front_info *front_info, + struct xen_drm_front_cfg *cfg); + +#endif /* __XEN_DRM_FRONT_CFG_H_ */

From: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com

Implement shared buffer handling according to the para-virtualized display device protocol at xen/interface/io/displif.h: - handle page directories according to displif protocol: - allocate and share page directories - grant references to the required set of pages for the page directory - allocate xen balllooned pages via Xen balloon driver with alloc_xenballooned_pages/free_xenballooned_pages - grant references to the required set of pages for the shared buffer itself - implement pages map/unmap for the buffers allocated by the backend (gnttab_map_refs/gnttab_unmap_refs)

Signed-off-by: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com --- drivers/gpu/drm/xen/Makefile | 1 + drivers/gpu/drm/xen/xen_drm_front.c | 8 + drivers/gpu/drm/xen/xen_drm_front_shbuf.c | 432 ++++++++++++++++++++++++++++++ drivers/gpu/drm/xen/xen_drm_front_shbuf.h | 72 +++++ 4 files changed, 513 insertions(+) create mode 100644 drivers/gpu/drm/xen/xen_drm_front_shbuf.c create mode 100644 drivers/gpu/drm/xen/xen_drm_front_shbuf.h

diff --git a/drivers/gpu/drm/xen/Makefile b/drivers/gpu/drm/xen/Makefile index 8417332f3b58..6c8c751f12ed 100644 --- a/drivers/gpu/drm/xen/Makefile +++ b/drivers/gpu/drm/xen/Makefile @@ -2,6 +2,7 @@

drm_xen_front-objs := xen_drm_front.o \ xen_drm_front_evtchnl.o \ + xen_drm_front_shbuf.o \ xen_drm_front_cfg.o

obj-$(CONFIG_DRM_XEN_FRONTEND) += drm_xen_front.o diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c index 8312dab862e2..fae631067c31 100644 --- a/drivers/gpu/drm/xen/xen_drm_front.c +++ b/drivers/gpu/drm/xen/xen_drm_front.c @@ -18,6 +18,7 @@

#include "xen_drm_front.h" #include "xen_drm_front_evtchnl.h" +#include "xen_drm_front_shbuf.h"

static void xen_drv_remove_internal(struct xen_drm_front_info *front_info) { @@ -187,6 +188,13 @@ static struct xenbus_driver xen_driver = {

static int __init xen_drv_init(void) { + /* At the moment we only support case with XEN_PAGE_SIZE == PAGE_SIZE */ + if (XEN_PAGE_SIZE != PAGE_SIZE) { + DRM_ERROR(XENDISPL_DRIVER_NAME ": different kernel and Xen page sizes are not supported: XEN_PAGE_SIZE (%lu) != PAGE_SIZE (%lu)\n", + XEN_PAGE_SIZE, PAGE_SIZE); + return -ENODEV; + } + if (!xen_domain()) return -ENODEV;

diff --git a/drivers/gpu/drm/xen/xen_drm_front_shbuf.c b/drivers/gpu/drm/xen/xen_drm_front_shbuf.c new file mode 100644 index 000000000000..0fde2d8f7706 --- /dev/null +++ b/drivers/gpu/drm/xen/xen_drm_front_shbuf.c @@ -0,0 +1,432 @@ +// 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); + if (buf->sgt) { + sg_free_table(buf->sgt); + kvfree(buf->pages); + } + 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) \ + ((phys_addr_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) +{ + if (buf->sgt) { + buf->pages = kvmalloc_array(buf->num_pages, + sizeof(struct page *), GFP_KERNEL); + if (!buf->pages) + return -ENOMEM; + + if (drm_prime_sg_to_page_addr_arrays(buf->sgt, buf->pages, + NULL, buf->num_pages) < 0) + return -EINVAL; + } + + 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; + + /* either pages or sgt, not both */ + if (unlikely(cfg->pages && cfg->sgt)) { + DRM_ERROR("Cannot handle buffer allocation with both pages and sg table provided\n"); + return NULL; + } + + buf = kzalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + return NULL; + + 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->sgt = cfg->sgt; + 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 new file mode 100644 index 000000000000..6c4fbc68f328 --- /dev/null +++ b/drivers/gpu/drm/xen/xen_drm_front_shbuf.h @@ -0,0 +1,72 @@ +/* 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; + + /* + * there are 2 ways to provide backing storage for this shared buffer: + * either pages or sgt. if buffer created from sgt then we own + * the pages and must free those ourselves on closure + */ + int num_pages; + struct page **pages; + + struct sg_table *sgt; + + 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; + struct sg_table *sgt; + 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_ */

From: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com

Implement GEM handling depending on driver mode of operation: depending on the requirements for the para-virtualized environment, namely requirements dictated by the accompanying DRM/(v)GPU drivers running in both host and guest environments, number of operating modes of para-virtualized display driver are supported: - display buffers can be allocated by either frontend driver or backend - display buffers can be allocated to be contiguous in memory or not

Note! Frontend driver itself has no dependency on contiguous memory for its operation.

1. Buffers allocated by the frontend driver.

The below modes of operation are configured at compile-time via frontend driver's kernel configuration.

1.1. Front driver configured to use GEM CMA helpers This use-case is useful when used with accompanying DRM/vGPU driver in guest domain which was designed to only work with contiguous buffers, e.g. DRM driver based on GEM CMA helpers: such drivers can only import contiguous PRIME buffers, thus requiring frontend driver to provide such. In order to implement this mode of operation para-virtualized frontend driver can be configured to use GEM CMA helpers.

1.2. Front driver doesn't use GEM CMA If accompanying drivers can cope with non-contiguous memory then, to lower pressure on CMA subsystem of the kernel, driver can allocate buffers from system memory.

Note! If used with accompanying DRM/(v)GPU drivers this mode of operation may require IOMMU support on the platform, so accompanying DRM/vGPU hardware can still reach display buffer memory while importing PRIME buffers from the frontend driver.

2. Buffers allocated by the backend

This mode of operation is run-time configured via guest domain configuration through XenStore entries.

For systems which do not provide IOMMU support, but having specific requirements for display buffers it is possible to allocate such buffers at backend side and share those with the frontend. For example, if host domain is 1:1 mapped and has DRM/GPU hardware expecting physically contiguous memory, this allows implementing zero-copying use-cases.

Note, while using this scenario the following should be considered: a) If guest domain dies then pages/grants received from the backend cannot be claimed back b) Misbehaving guest may send too many requests to the backend exhausting its grant references and memory (consider this from security POV).

Note! Configuration options 1.1 (contiguous display buffers) and 2 (backend allocated buffers) are not supported at the same time.

Handle communication with the backend: - send requests and wait for the responses according to the displif protocol - serialize access to the communication channel - time-out used for backend communication is set to 3000 ms - manage display buffers shared with the backend

Signed-off-by: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com --- drivers/gpu/drm/xen/Kconfig | 13 ++ drivers/gpu/drm/xen/Makefile | 6 + drivers/gpu/drm/xen/xen_drm_front.c | 324 ++++++++++++++++++++++++++- drivers/gpu/drm/xen/xen_drm_front.h | 8 + drivers/gpu/drm/xen/xen_drm_front_conn.c | 31 ++- drivers/gpu/drm/xen/xen_drm_front_drv.c | 70 +++++- drivers/gpu/drm/xen/xen_drm_front_drv.h | 13 ++ drivers/gpu/drm/xen/xen_drm_front_gem.c | 335 ++++++++++++++++++++++++++++ drivers/gpu/drm/xen/xen_drm_front_gem.h | 41 ++++ drivers/gpu/drm/xen/xen_drm_front_gem_cma.c | 74 ++++++ drivers/gpu/drm/xen/xen_drm_front_kms.c | 44 +++- drivers/gpu/drm/xen/xen_drm_front_kms.h | 3 + 12 files changed, 953 insertions(+), 9 deletions(-) create mode 100644 drivers/gpu/drm/xen/xen_drm_front_gem.c create mode 100644 drivers/gpu/drm/xen/xen_drm_front_gem.h create mode 100644 drivers/gpu/drm/xen/xen_drm_front_gem_cma.c

diff --git a/drivers/gpu/drm/xen/Kconfig b/drivers/gpu/drm/xen/Kconfig index 4cca160782ab..4f4abc91f3b6 100644 --- a/drivers/gpu/drm/xen/Kconfig +++ b/drivers/gpu/drm/xen/Kconfig @@ -15,3 +15,16 @@ config DRM_XEN_FRONTEND help Choose this option if you want to enable a para-virtualized frontend DRM/KMS driver for Xen guest OSes. + +config DRM_XEN_FRONTEND_CMA + bool "Use DRM CMA to allocate dumb buffers" + depends on DRM_XEN_FRONTEND + select DRM_KMS_CMA_HELPER + select DRM_GEM_CMA_HELPER + help + Use DRM CMA helpers to allocate display buffers. + This is useful for the use-cases when guest driver needs to + share or export buffers to other drivers which only expect + contiguous buffers. + Note: in this mode driver cannot use buffers allocated + by the backend. diff --git a/drivers/gpu/drm/xen/Makefile b/drivers/gpu/drm/xen/Makefile index a7858693baae..ac1b82f2a860 100644 --- a/drivers/gpu/drm/xen/Makefile +++ b/drivers/gpu/drm/xen/Makefile @@ -8,4 +8,10 @@ drm_xen_front-objs := xen_drm_front.o \ xen_drm_front_shbuf.o \ xen_drm_front_cfg.o

+ifeq ($(CONFIG_DRM_XEN_FRONTEND_CMA),y) + drm_xen_front-objs += xen_drm_front_gem_cma.o +else + drm_xen_front-objs += xen_drm_front_gem.o +endif + obj-$(CONFIG_DRM_XEN_FRONTEND) += drm_xen_front.o diff --git a/drivers/gpu/drm/xen/xen_drm_front.c b/drivers/gpu/drm/xen/xen_drm_front.c index 4e5059a280ba..dbabdf98f896 100644 --- a/drivers/gpu/drm/xen/xen_drm_front.c +++ b/drivers/gpu/drm/xen/xen_drm_front.c @@ -23,11 +23,142 @@ #include "xen_drm_front_evtchnl.h" #include "xen_drm_front_shbuf.h"

+struct xen_drm_front_dbuf { + struct list_head list; + uint64_t dbuf_cookie; + uint64_t fb_cookie; + struct xen_drm_front_shbuf *shbuf; +}; + +static int dbuf_add_to_list(struct xen_drm_front_info *front_info, + struct xen_drm_front_shbuf *shbuf, uint64_t 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, + uint64_t dbuf_cookie) +{ + struct xen_drm_front_dbuf *buf, *q; + + list_for_each_entry_safe(buf, q, dbuf_list, list) + if (buf->dbuf_cookie == dbuf_cookie) + return buf; + + return NULL; +} + +static void dbuf_flush_fb(struct list_head *dbuf_list, uint64_t 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, uint64_t dbuf_cookie) +{ + struct xen_drm_front_dbuf *buf, *q; + + 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); + kfree(buf); + break; + } +} + +static void dbuf_free_all(struct list_head *dbuf_list) +{ + struct xen_drm_front_dbuf *buf, *q; + + 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); + kfree(buf); + } +} + +static struct xendispl_req *be_prepare_req( + struct xen_drm_front_evtchnl *evtchnl, uint8_t operation) +{ + struct xendispl_req *req; + + req = RING_GET_REQUEST(&evtchnl->u.req.ring, + evtchnl->u.req.ring.req_prod_pvt); + req->operation = operation; + req->id = evtchnl->evt_next_id++; + evtchnl->evt_id = req->id; + return req; +} + +static int be_stream_do_io(struct xen_drm_front_evtchnl *evtchnl, + struct xendispl_req *req) +{ + reinit_completion(&evtchnl->u.req.completion); + if (unlikely(evtchnl->state != EVTCHNL_STATE_CONNECTED)) + return -EIO; + + xen_drm_front_evtchnl_flush(evtchnl); + return 0; +} + +static int be_stream_wait_io(struct xen_drm_front_evtchnl *evtchnl) +{ + if (wait_for_completion_timeout(&evtchnl->u.req.completion, + msecs_to_jiffies(XEN_DRM_FRONT_WAIT_BACK_MS)) <= 0) + return -ETIMEDOUT; + + return evtchnl->u.req.resp_status; +} + int xen_drm_front_mode_set(struct xen_drm_front_drm_pipeline *pipeline, uint32_t x, uint32_t y, uint32_t width, uint32_t height, uint32_t bpp, uint64_t fb_cookie) { - return 0; + struct xen_drm_front_evtchnl *evtchnl; + struct xen_drm_front_info *front_info; + struct xendispl_req *req; + unsigned long flags; + int ret; + + front_info = pipeline->drm_info->front_info; + evtchnl = &front_info->evt_pairs[pipeline->index].req; + if (unlikely(!evtchnl)) + return -EIO; + + mutex_lock(&front_info->req_io_lock); + + spin_lock_irqsave(&front_info->io_lock, flags); + req = be_prepare_req(evtchnl, XENDISPL_OP_SET_CONFIG); + req->op.set_config.x = x; + req->op.set_config.y = y; + req->op.set_config.width = width; + req->op.set_config.height = height; + req->op.set_config.bpp = bpp; + req->op.set_config.fb_cookie = fb_cookie; + + ret = be_stream_do_io(evtchnl, req); + spin_unlock_irqrestore(&front_info->io_lock, flags); + + if (ret == 0) + ret = be_stream_wait_io(evtchnl); + + mutex_unlock(&front_info->req_io_lock); + return ret; }

static int be_dbuf_create_int(struct xen_drm_front_info *front_info, @@ -35,7 +166,69 @@ static int be_dbuf_create_int(struct xen_drm_front_info *front_info, uint32_t bpp, uint64_t size, struct page **pages, struct sg_table *sgt) { + struct xen_drm_front_evtchnl *evtchnl; + struct xen_drm_front_shbuf *shbuf; + struct xendispl_req *req; + struct xen_drm_front_shbuf_cfg buf_cfg; + unsigned long flags; + int ret; + + evtchnl = &front_info->evt_pairs[GENERIC_OP_EVT_CHNL].req; + if (unlikely(!evtchnl)) + return -EIO; + + memset(&buf_cfg, 0, sizeof(buf_cfg)); + buf_cfg.xb_dev = front_info->xb_dev; + buf_cfg.pages = pages; + buf_cfg.size = size; + buf_cfg.sgt = sgt; + buf_cfg.be_alloc = front_info->cfg.be_alloc; + + shbuf = xen_drm_front_shbuf_alloc(&buf_cfg); + if (!shbuf) + return -ENOMEM; + + ret = dbuf_add_to_list(front_info, shbuf, dbuf_cookie); + if (ret < 0) { + xen_drm_front_shbuf_free(shbuf); + return ret; + } + + mutex_lock(&front_info->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); + req->op.dbuf_create.buffer_sz = size; + req->op.dbuf_create.dbuf_cookie = dbuf_cookie; + req->op.dbuf_create.width = width; + req->op.dbuf_create.height = height; + req->op.dbuf_create.bpp = bpp; + if (buf_cfg.be_alloc) + req->op.dbuf_create.flags |= XENDISPL_DBUF_FLG_REQ_ALLOC; + + ret = be_stream_do_io(evtchnl, req); + spin_unlock_irqrestore(&front_info->io_lock, flags); + + if (ret < 0) + goto fail; + + ret = be_stream_wait_io(evtchnl); + if (ret < 0) + goto fail; + + ret = xen_drm_front_shbuf_map(shbuf); + if (ret < 0) + goto fail; + + mutex_unlock(&front_info->req_io_lock); return 0; + +fail: + mutex_unlock(&front_info->req_io_lock); + dbuf_free(&front_info->dbuf_list, dbuf_cookie); + return ret; }

int xen_drm_front_dbuf_create_from_sgt(struct xen_drm_front_info *front_info, @@ -57,26 +250,144 @@ int xen_drm_front_dbuf_create_from_pages(struct xen_drm_front_info *front_info, int xen_drm_front_dbuf_destroy(struct xen_drm_front_info *front_info, uint64_t dbuf_cookie) { - return 0; + struct xen_drm_front_evtchnl *evtchnl; + struct xendispl_req *req; + unsigned long flags; + bool be_alloc; + int ret; + + evtchnl = &front_info->evt_pairs[GENERIC_OP_EVT_CHNL].req; + if (unlikely(!evtchnl)) + return -EIO; + + be_alloc = front_info->cfg.be_alloc; + + /* + * for the backend allocated buffer release references now, so backend + * can free the buffer + */ + if (be_alloc) + dbuf_free(&front_info->dbuf_list, dbuf_cookie); + + mutex_lock(&front_info->req_io_lock); + + spin_lock_irqsave(&front_info->io_lock, flags); + req = be_prepare_req(evtchnl, XENDISPL_OP_DBUF_DESTROY); + req->op.dbuf_destroy.dbuf_cookie = dbuf_cookie; + + ret = be_stream_do_io(evtchnl, req); + spin_unlock_irqrestore(&front_info->io_lock, flags); + + if (ret == 0) + ret = be_stream_wait_io(evtchnl); + + /* + * do this regardless of communication status with the backend: + * if we cannot remove remote resources remove what we can locally + */ + if (!be_alloc) + dbuf_free(&front_info->dbuf_list, dbuf_cookie); + + mutex_unlock(&front_info->req_io_lock); + return ret; }

int xen_drm_front_fb_attach(struct xen_drm_front_info *front_info, uint64_t dbuf_cookie, uint64_t fb_cookie, uint32_t width, uint32_t height, uint32_t pixel_format) { - return 0; + struct xen_drm_front_evtchnl *evtchnl; + struct xen_drm_front_dbuf *buf; + struct xendispl_req *req; + unsigned long flags; + int ret; + + evtchnl = &front_info->evt_pairs[GENERIC_OP_EVT_CHNL].req; + if (unlikely(!evtchnl)) + return -EIO; + + buf = dbuf_get(&front_info->dbuf_list, dbuf_cookie); + if (!buf) + return -EINVAL; + + buf->fb_cookie = fb_cookie; + + mutex_lock(&front_info->req_io_lock); + + spin_lock_irqsave(&front_info->io_lock, flags); + req = be_prepare_req(evtchnl, XENDISPL_OP_FB_ATTACH); + req->op.fb_attach.dbuf_cookie = dbuf_cookie; + req->op.fb_attach.fb_cookie = fb_cookie; + req->op.fb_attach.width = width; + req->op.fb_attach.height = height; + req->op.fb_attach.pixel_format = pixel_format; + + ret = be_stream_do_io(evtchnl, req); + spin_unlock_irqrestore(&front_info->io_lock, flags); + + if (ret == 0) + ret = be_stream_wait_io(evtchnl); + + mutex_unlock(&front_info->req_io_lock); + return ret; }

int xen_drm_front_fb_detach(struct xen_drm_front_info *front_info, uint64_t fb_cookie) { - return 0; + struct xen_drm_front_evtchnl *evtchnl; + struct xendispl_req *req; + unsigned long flags; + int ret; + + evtchnl = &front_info->evt_pairs[GENERIC_OP_EVT_CHNL].req; + if (unlikely(!evtchnl)) + return -EIO; + + mutex_lock(&front_info->req_io_lock); + + spin_lock_irqsave(&front_info->io_lock, flags); + req = be_prepare_req(evtchnl, XENDISPL_OP_FB_DETACH); + req->op.fb_detach.fb_cookie = fb_cookie; + + ret = be_stream_do_io(evtchnl, req); + spin_unlock_irqrestore(&front_info->io_lock, flags); + + if (ret == 0) + ret = be_stream_wait_io(evtchnl); + + mutex_unlock(&front_info->req_io_lock); + return ret; }

int xen_drm_front_page_flip(struct xen_drm_front_info *front_info, int conn_idx, uint64_t fb_cookie) { - return 0; + struct xen_drm_front_evtchnl *evtchnl; + struct xendispl_req *req; + unsigned long flags; + int ret; + + 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(&front_info->req_io_lock); + + spin_lock_irqsave(&front_info->io_lock, flags); + req = be_prepare_req(evtchnl, XENDISPL_OP_PG_FLIP); + req->op.pg_flip.fb_cookie = fb_cookie; + + ret = be_stream_do_io(evtchnl, req); + spin_unlock_irqrestore(&front_info->io_lock, flags); + + if (ret == 0) + ret = be_stream_wait_io(evtchnl); + + mutex_unlock(&front_info->req_io_lock); + return ret; }

void xen_drm_front_unload(struct xen_drm_front_info *front_info) @@ -163,6 +474,7 @@ static void xen_drv_remove_internal(struct xen_drm_front_info *front_info) { xen_drm_drv_deinit(front_info); xen_drm_front_evtchnl_free_all(front_info); + dbuf_free_all(&front_info->dbuf_list); }

static int displback_initwait(struct xen_drm_front_info *front_info) @@ -292,6 +604,8 @@ static int xen_drv_probe(struct xenbus_device *xb_dev,

front_info->xb_dev = xb_dev; spin_lock_init(&front_info->io_lock); + mutex_init(&front_info->req_io_lock); + INIT_LIST_HEAD(&front_info->dbuf_list); front_info->drm_pdrv_registered = false; dev_set_drvdata(&xb_dev->dev, front_info); return xenbus_switch_state(xb_dev, XenbusStateInitialising); diff --git a/drivers/gpu/drm/xen/xen_drm_front.h b/drivers/gpu/drm/xen/xen_drm_front.h index d964c4bd4fb6..93c58c4e87d2 100644 --- a/drivers/gpu/drm/xen/xen_drm_front.h +++ b/drivers/gpu/drm/xen/xen_drm_front.h @@ -15,6 +15,9 @@

#include "xen_drm_front_cfg.h"

+/* timeout in ms to wait for backend to respond */ +#define XEN_DRM_FRONT_WAIT_BACK_MS 3000 + #ifndef GRANT_INVALID_REF /* * Note on usage of grant reference 0 as invalid grant reference: @@ -30,6 +33,8 @@ struct xen_drm_front_info { struct xenbus_device *xb_dev; /* to protect data between backend IO code and interrupt handler */ spinlock_t io_lock; + /* serializer for backend IO: request/response */ + struct mutex req_io_lock; bool drm_pdrv_registered; /* virtual DRM platform device */ struct platform_device *drm_pdev; @@ -37,6 +42,9 @@ struct xen_drm_front_info { int num_evt_pairs; struct xen_drm_front_evtchnl_pair *evt_pairs; struct xen_drm_front_cfg cfg; + + /* display buffers */ + struct list_head dbuf_list; };

int xen_drm_front_mode_set(struct xen_drm_front_drm_pipeline *pipeline, diff --git a/drivers/gpu/drm/xen/xen_drm_front_conn.c b/drivers/gpu/drm/xen/xen_drm_front_conn.c index 382c8a9da7e6..aaa1cfff4797 100644 --- a/drivers/gpu/drm/xen/xen_drm_front_conn.c +++ b/drivers/gpu/drm/xen/xen_drm_front_conn.c @@ -15,6 +15,7 @@

#include "xen_drm_front_conn.h" #include "xen_drm_front_drv.h" +#include "xen_drm_front_kms.h"

static struct xen_drm_front_drm_pipeline * to_xen_drm_pipeline(struct drm_connector *connector) @@ -43,10 +44,28 @@ static int connector_detect(struct drm_connector *connector, struct drm_modeset_acquire_ctx *ctx, bool force) { + struct xen_drm_front_drm_pipeline *pipeline = + to_xen_drm_pipeline(connector); + struct xen_drm_front_info *front_info = pipeline->drm_info->front_info; + unsigned long flags; + + /* check if there is a frame done event time-out */ + spin_lock_irqsave(&front_info->io_lock, flags); + if (pipeline->pflip_timeout && + time_after_eq(jiffies, pipeline->pflip_timeout)) { + DRM_ERROR("Frame done event timed-out\n"); + + pipeline->pflip_timeout = 0; + pipeline->conn_connected = false; + xen_drm_front_kms_send_pending_event(pipeline); + } + spin_unlock_irqrestore(&front_info->io_lock, flags); + if (drm_dev_is_unplugged(connector->dev)) - return connector_status_disconnected; + pipeline->conn_connected = false;

- return connector_status_connected; + return pipeline->conn_connected ? connector_status_connected : + connector_status_disconnected; }

#define XEN_DRM_NUM_VIDEO_MODES 1 @@ -112,8 +131,16 @@ static const struct drm_connector_funcs connector_funcs = { int xen_drm_front_conn_init(struct xen_drm_front_drm_info *drm_info, struct drm_connector *connector) { + struct xen_drm_front_drm_pipeline *pipeline = + to_xen_drm_pipeline(connector); + drm_connector_helper_add(connector, &connector_helper_funcs);

+ pipeline->conn_connected = true; + + connector->polled = DRM_CONNECTOR_POLL_CONNECT | + DRM_CONNECTOR_POLL_DISCONNECT; + return drm_connector_init(drm_info->drm_dev, connector, &connector_funcs, DRM_MODE_CONNECTOR_VIRTUAL); } diff --git a/drivers/gpu/drm/xen/xen_drm_front_drv.c b/drivers/gpu/drm/xen/xen_drm_front_drv.c index 8887ac054601..3edefa20f14f 100644 --- a/drivers/gpu/drm/xen/xen_drm_front_drv.c +++ b/drivers/gpu/drm/xen/xen_drm_front_drv.c @@ -10,17 +10,65 @@

#include <drm/drmP.h> #include <drm/drm_atomic_helper.h> +#include <drm/drm_crtc_helper.h> #include <drm/drm_gem.h> +#include <drm/drm_gem_cma_helper.h>

#include "xen_drm_front.h" #include "xen_drm_front_cfg.h" #include "xen_drm_front_drv.h" +#include "xen_drm_front_gem.h" #include "xen_drm_front_kms.h"

static int dumb_create(struct drm_file *filp, struct drm_device *dev, struct drm_mode_create_dumb *args) { - return -EINVAL; + struct xen_drm_front_drm_info *drm_info = dev->dev_private; + struct drm_gem_object *obj; + int ret; + + ret = xen_drm_front_gem_dumb_create(filp, dev, args); + if (ret) + goto fail; + + obj = drm_gem_object_lookup(filp, args->handle); + if (!obj) { + ret = -ENOENT; + goto fail_destroy; + } + + drm_gem_object_unreference_unlocked(obj); + + /* + * In case of CONFIG_DRM_XEN_FRONTEND_CMA gem_obj is constructed + * via DRM CMA helpers and doesn't have ->pages allocated + * (xendrm_gem_get_pages will return NULL), but instead can provide + * sg table + */ + if (xen_drm_front_gem_get_pages(obj)) + ret = xen_drm_front_dbuf_create_from_pages( + drm_info->front_info, + xen_drm_front_dbuf_to_cookie(obj), + args->width, args->height, args->bpp, + args->size, + xen_drm_front_gem_get_pages(obj)); + else + ret = xen_drm_front_dbuf_create_from_sgt( + drm_info->front_info, + xen_drm_front_dbuf_to_cookie(obj), + args->width, args->height, args->bpp, + args->size, + xen_drm_front_gem_get_sg_table(obj)); + if (ret) + goto fail_destroy; + + return 0; + +fail_destroy: + drm_gem_dumb_destroy(filp, dev, args->handle); +fail: + DRM_ERROR("Failed to create dumb buffer: %d\n", ret); + return ret; }

static void free_object(struct drm_gem_object *obj) @@ -29,6 +77,7 @@ static void free_object(struct drm_gem_object *obj)

xen_drm_front_dbuf_destroy(drm_info->front_info, xen_drm_front_dbuf_to_cookie(obj)); + xen_drm_front_gem_free_object(obj); }

void xen_drm_front_on_frame_done(struct platform_device *pdev, @@ -61,6 +110,11 @@ static const struct file_operations xen_drm_fops = { .poll = drm_poll, .read = drm_read, .llseek = no_llseek, +#ifdef CONFIG_DRM_XEN_FRONTEND_CMA + .mmap = drm_gem_cma_mmap, +#else + .mmap = xen_drm_front_gem_mmap, +#endif };

static const struct vm_operations_struct xen_drm_vm_ops = { @@ -78,6 +132,8 @@ struct drm_driver xen_drm_driver = { .prime_fd_to_handle = drm_gem_prime_fd_to_handle, .gem_prime_import = drm_gem_prime_import, .gem_prime_export = drm_gem_prime_export, + .gem_prime_import_sg_table = xen_drm_front_gem_import_sg_table, + .gem_prime_get_sg_table = xen_drm_front_gem_get_sg_table, .dumb_create = dumb_create, .fops = &xen_drm_fops, .name = "xendrm-du", @@ -85,6 +141,16 @@ struct drm_driver xen_drm_driver = { .date = "20180221", .major = 1, .minor = 0, + +#ifdef CONFIG_DRM_XEN_FRONTEND_CMA + .gem_prime_vmap = drm_gem_cma_prime_vmap, + .gem_prime_vunmap = drm_gem_cma_prime_vunmap, + .gem_prime_mmap = drm_gem_cma_prime_mmap, +#else + .gem_prime_vmap = xen_drm_front_gem_prime_vmap, + .gem_prime_vunmap = xen_drm_front_gem_prime_vunmap, + .gem_prime_mmap = xen_drm_front_gem_prime_mmap, +#endif };

int xen_drm_front_drv_probe(struct platform_device *pdev) @@ -132,6 +198,7 @@ int xen_drm_front_drv_probe(struct platform_device *pdev) fail_register: drm_dev_unregister(dev); fail_modeset: + drm_kms_helper_poll_fini(dev); drm_mode_config_cleanup(dev); return ret; } @@ -142,6 +209,7 @@ int xen_drm_front_drv_remove(struct platform_device *pdev) struct drm_device *dev = drm_info->drm_dev;

if (dev) { + drm_kms_helper_poll_fini(dev); drm_dev_unregister(dev); drm_atomic_helper_shutdown(dev); drm_mode_config_cleanup(dev); diff --git a/drivers/gpu/drm/xen/xen_drm_front_drv.h b/drivers/gpu/drm/xen/xen_drm_front_drv.h index cf3517b61979..53656f858c10 100644 --- a/drivers/gpu/drm/xen/xen_drm_front_drv.h +++ b/drivers/gpu/drm/xen/xen_drm_front_drv.h @@ -30,6 +30,19 @@ struct xen_drm_front_drm_pipeline { int width, height;

struct drm_pending_vblank_event *pending_event; + + /* + * pflip_timeout is set to current jiffies once we send a page flip and + * reset to 0 when we receive frame done event from the backed. + * It is checked during drm_connector_helper_funcs.detect_ctx to detect + * time-outs for frame done event, e.g. due to backend errors. + * + * This must be protected with front_info->io_lock, so races between + * interrupt handler and rest of the code are properly handled. + */ + unsigned long pflip_timeout; + + bool conn_connected; };

struct xen_drm_front_drm_info { diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c new file mode 100644 index 000000000000..f6c54ab0fdcb --- /dev/null +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c @@ -0,0 +1,335 @@ +// 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 "xen_drm_front_gem.h" + +#include <drm/drmP.h> +#include <drm/drm_crtc_helper.h> +#include <drm/drm_fb_helper.h> +#include <drm/drm_gem.h> + +#include <linux/dma-buf.h> +#include <linux/scatterlist.h> +#include <linux/shmem_fs.h> + +#include <xen/balloon.h> + +#include "xen_drm_front.h" +#include "xen_drm_front_drv.h" +#include "xen_drm_front_shbuf.h" + +struct xen_gem_object { + struct drm_gem_object base; + + size_t num_pages; + struct page **pages; + + /* set for buffers allocated by the backend */ + bool be_alloc; + + /* this is for imported PRIME buffer */ + struct sg_table *sgt_imported; +}; + +static inline struct xen_gem_object *to_xen_gem_obj( + struct drm_gem_object *gem_obj) +{ + return container_of(gem_obj, struct xen_gem_object, base); +} + +static int gem_alloc_pages_array(struct xen_gem_object *xen_obj, + size_t buf_size) +{ + xen_obj->num_pages = DIV_ROUND_UP(buf_size, PAGE_SIZE); + xen_obj->pages = kvmalloc_array(xen_obj->num_pages, + sizeof(struct page *), GFP_KERNEL); + return xen_obj->pages == NULL ? -ENOMEM : 0; +} + +static void gem_free_pages_array(struct xen_gem_object *xen_obj) +{ + kvfree(xen_obj->pages); + xen_obj->pages = NULL; +} + +static struct xen_gem_object *gem_create_obj(struct drm_device *dev, + size_t size) +{ + struct xen_gem_object *xen_obj; + int ret; + + xen_obj = kzalloc(sizeof(*xen_obj), GFP_KERNEL); + if (!xen_obj) + return ERR_PTR(-ENOMEM); + + ret = drm_gem_object_init(dev, &xen_obj->base, size); + if (ret < 0) { + kfree(xen_obj); + return ERR_PTR(ret); + } + + return xen_obj; +} + +static struct xen_gem_object *gem_create(struct drm_device *dev, size_t size) +{ + struct xen_drm_front_drm_info *drm_info = dev->dev_private; + struct xen_gem_object *xen_obj; + int ret; + + size = round_up(size, PAGE_SIZE); + xen_obj = gem_create_obj(dev, size); + if (IS_ERR_OR_NULL(xen_obj)) + return xen_obj; + + if (drm_info->cfg->be_alloc) { + /* + * backend will allocate space for this buffer, so + * only allocate array of pointers to pages + */ + ret = gem_alloc_pages_array(xen_obj, size); + if (ret < 0) + goto fail; + + /* + * allocate ballooned pages which will be used to map + * grant references provided by the backend + */ + ret = alloc_xenballooned_pages(xen_obj->num_pages, + xen_obj->pages); + if (ret < 0) { + DRM_ERROR("Cannot allocate %zu ballooned pages: %d\n", + xen_obj->num_pages, ret); + gem_free_pages_array(xen_obj); + goto fail; + } + + xen_obj->be_alloc = true; + return xen_obj; + } + /* + * need to allocate backing pages now, so we can share those + * with the backend + */ + xen_obj->num_pages = DIV_ROUND_UP(size, PAGE_SIZE); + xen_obj->pages = drm_gem_get_pages(&xen_obj->base); + if (IS_ERR_OR_NULL(xen_obj->pages)) { + ret = PTR_ERR(xen_obj->pages); + xen_obj->pages = NULL; + goto fail; + } + + return xen_obj; + +fail: + DRM_ERROR("Failed to allocate buffer with size %zu\n", size); + return ERR_PTR(ret); +} + +static struct xen_gem_object *gem_create_with_handle(struct drm_file *filp, + struct drm_device *dev, size_t size, uint32_t *handle) +{ + struct xen_gem_object *xen_obj; + struct drm_gem_object *gem_obj; + int ret; + + xen_obj = gem_create(dev, size); + if (IS_ERR_OR_NULL(xen_obj)) + return xen_obj; + + gem_obj = &xen_obj->base; + ret = drm_gem_handle_create(filp, gem_obj, handle); + /* handle holds the reference */ + drm_gem_object_unreference_unlocked(gem_obj); + if (ret < 0) + return ERR_PTR(ret); + + return xen_obj; +} + +int xen_drm_front_gem_dumb_create(struct drm_file *filp, struct drm_device *dev, + struct drm_mode_create_dumb *args) +{ + struct xen_gem_object *xen_obj; + + args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8); + args->size = args->pitch * args->height; + + xen_obj = gem_create_with_handle(filp, dev, args->size, &args->handle); + if (IS_ERR_OR_NULL(xen_obj)) + return xen_obj == NULL ? -ENOMEM : PTR_ERR(xen_obj); + + return 0; +} + +void xen_drm_front_gem_free_object(struct drm_gem_object *gem_obj) +{ + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj); + + if (xen_obj->base.import_attach) { + drm_prime_gem_destroy(&xen_obj->base, xen_obj->sgt_imported); + gem_free_pages_array(xen_obj); + } else { + if (xen_obj->pages) { + if (xen_obj->be_alloc) { + free_xenballooned_pages(xen_obj->num_pages, + xen_obj->pages); + gem_free_pages_array(xen_obj); + } else + drm_gem_put_pages(&xen_obj->base, + xen_obj->pages, true, false); + } + } + drm_gem_object_release(gem_obj); + kfree(xen_obj); +} + +struct page **xen_drm_front_gem_get_pages(struct drm_gem_object *gem_obj) +{ + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj); + + return xen_obj->pages; +} + +struct sg_table *xen_drm_front_gem_get_sg_table(struct drm_gem_object *gem_obj) +{ + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj); + + if (!xen_obj->pages) + return NULL; + + return drm_prime_pages_to_sg(xen_obj->pages, xen_obj->num_pages); +} + +struct drm_gem_object *xen_drm_front_gem_import_sg_table(struct drm_device *dev, + struct dma_buf_attachment *attach, struct sg_table *sgt) +{ + struct xen_drm_front_drm_info *drm_info = dev->dev_private; + struct xen_gem_object *xen_obj; + size_t size; + int ret; + + size = attach->dmabuf->size; + xen_obj = gem_create_obj(dev, size); + if (IS_ERR_OR_NULL(xen_obj)) + return ERR_CAST(xen_obj); + + ret = gem_alloc_pages_array(xen_obj, size); + if (ret < 0) + return ERR_PTR(ret); + + xen_obj->sgt_imported = sgt; + + ret = drm_prime_sg_to_page_addr_arrays(sgt, xen_obj->pages, + NULL, xen_obj->num_pages); + if (ret < 0) + return ERR_PTR(ret); + + /* + * N.B. Although we have an API to create display buffer from sgt + * we use pages API, because we still need those for GEM handling, + * e.g. for mapping etc. + */ + ret = xen_drm_front_dbuf_create_from_pages( + drm_info->front_info, + xen_drm_front_dbuf_to_cookie(&xen_obj->base), + 0, 0, 0, size, xen_obj->pages); + if (ret < 0) + return ERR_PTR(ret); + + DRM_DEBUG("Imported buffer of size %zu with nents %u\n", + size, sgt->nents); + + return &xen_obj->base; +} + +static int gem_mmap_obj(struct xen_gem_object *xen_obj, + struct vm_area_struct *vma) +{ + unsigned long addr = vma->vm_start; + int i; + + /* + * clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the + * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map + * the whole buffer. + */ + vma->vm_flags &= ~VM_PFNMAP; + vma->vm_flags |= VM_MIXEDMAP; + vma->vm_pgoff = 0; + vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags)); + + /* + * vm_operations_struct.fault handler will be called if CPU access + * to VM is here. For GPUs this isn't the case, because CPU + * doesn't touch the memory. Insert pages now, so both CPU and GPU are + * happy. + * FIXME: as we insert all the pages now then no .fault handler must + * be called, so don't provide one + */ + for (i = 0; i < xen_obj->num_pages; i++) { + int ret; + + ret = vm_insert_page(vma, addr, xen_obj->pages[i]); + if (ret < 0) { + DRM_ERROR("Failed to insert pages into vma: %d\n", ret); + return ret; + } + + addr += PAGE_SIZE; + } + return 0; +} + +int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma) +{ + struct xen_gem_object *xen_obj; + struct drm_gem_object *gem_obj; + int ret; + + ret = drm_gem_mmap(filp, vma); + if (ret < 0) + return ret; + + gem_obj = vma->vm_private_data; + xen_obj = to_xen_gem_obj(gem_obj); + return gem_mmap_obj(xen_obj, vma); +} + +void *xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj) +{ + struct xen_gem_object *xen_obj = to_xen_gem_obj(gem_obj); + + if (!xen_obj->pages) + return NULL; + + return vmap(xen_obj->pages, xen_obj->num_pages, + VM_MAP, pgprot_writecombine(PAGE_KERNEL)); +} + +void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj, + void *vaddr) +{ + vunmap(vaddr); +} + +int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj, + struct vm_area_struct *vma) +{ + struct xen_gem_object *xen_obj; + int ret; + + ret = drm_gem_mmap_obj(gem_obj, gem_obj->size, vma); + if (ret < 0) + return ret; + + xen_obj = to_xen_gem_obj(gem_obj); + return gem_mmap_obj(xen_obj, vma); +} diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.h b/drivers/gpu/drm/xen/xen_drm_front_gem.h new file mode 100644 index 000000000000..8a35bc98c1c1 --- /dev/null +++ b/drivers/gpu/drm/xen/xen_drm_front_gem.h @@ -0,0 +1,41 @@ +/* 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_GEM_H +#define __XEN_DRM_FRONT_GEM_H + +#include <drm/drmP.h> + +int xen_drm_front_gem_dumb_create(struct drm_file *filp, struct drm_device *dev, + struct drm_mode_create_dumb *args); + +struct drm_gem_object *xen_drm_front_gem_import_sg_table(struct drm_device *dev, + struct dma_buf_attachment *attach, struct sg_table *sgt); + +struct sg_table *xen_drm_front_gem_get_sg_table(struct drm_gem_object *gem_obj); + +struct page **xen_drm_front_gem_get_pages(struct drm_gem_object *obj); + +void xen_drm_front_gem_free_object(struct drm_gem_object *gem_obj); + +#ifndef CONFIG_DRM_XEN_FRONTEND_CMA + +int xen_drm_front_gem_mmap(struct file *filp, struct vm_area_struct *vma); + +void *xen_drm_front_gem_prime_vmap(struct drm_gem_object *gem_obj); + +void xen_drm_front_gem_prime_vunmap(struct drm_gem_object *gem_obj, + void *vaddr); + +int xen_drm_front_gem_prime_mmap(struct drm_gem_object *gem_obj, + struct vm_area_struct *vma); +#endif + +#endif /* __XEN_DRM_FRONT_GEM_H */ diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem_cma.c b/drivers/gpu/drm/xen/xen_drm_front_gem_cma.c new file mode 100644 index 000000000000..7978bc42afd0 --- /dev/null +++ b/drivers/gpu/drm/xen/xen_drm_front_gem_cma.c @@ -0,0 +1,74 @@ +// 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> +#include <drm/drm_gem.h> +#include <drm/drm_fb_cma_helper.h> +#include <drm/drm_gem_cma_helper.h> + +#include "xen_drm_front.h" +#include "xen_drm_front_drv.h" +#include "xen_drm_front_gem.h" + +struct drm_gem_object *xen_drm_front_gem_import_sg_table(struct drm_device *dev, + struct dma_buf_attachment *attach, struct sg_table *sgt) +{ + struct xen_drm_front_drm_info *drm_info = dev->dev_private; + struct drm_gem_object *gem_obj; + struct drm_gem_cma_object *cma_obj; + int ret; + + gem_obj = drm_gem_cma_prime_import_sg_table(dev, attach, sgt); + if (IS_ERR_OR_NULL(gem_obj)) + return gem_obj; + + cma_obj = to_drm_gem_cma_obj(gem_obj); + + ret = xen_drm_front_dbuf_create_from_sgt( + drm_info->front_info, + xen_drm_front_dbuf_to_cookie(gem_obj), + 0, 0, 0, gem_obj->size, + drm_gem_cma_prime_get_sg_table(gem_obj)); + if (ret < 0) + return ERR_PTR(ret); + + DRM_DEBUG("Imported CMA buffer of size %zu\n", gem_obj->size); + + return gem_obj; +} + +struct sg_table *xen_drm_front_gem_get_sg_table(struct drm_gem_object *gem_obj) +{ + return drm_gem_cma_prime_get_sg_table(gem_obj); +} + +int xen_drm_front_gem_dumb_create(struct drm_file *filp, struct drm_device *dev, + struct drm_mode_create_dumb *args) +{ + struct xen_drm_front_drm_info *drm_info = dev->dev_private; + + if (drm_info->cfg->be_alloc) { + /* This use-case is not yet supported and probably won't be */ + DRM_ERROR("Backend allocated buffers and CMA helpers are not supported at the same time\n"); + return -EINVAL; + } + + return drm_gem_cma_dumb_create(filp, dev, args); +} + +void xen_drm_front_gem_free_object(struct drm_gem_object *gem_obj) +{ + drm_gem_cma_free_object(gem_obj); +} + +struct page **xen_drm_front_gem_get_pages(struct drm_gem_object *gem_obj) +{ + return NULL; +} diff --git a/drivers/gpu/drm/xen/xen_drm_front_kms.c b/drivers/gpu/drm/xen/xen_drm_front_kms.c index 468995b6bf7a..7ad45281b318 100644 --- a/drivers/gpu/drm/xen/xen_drm_front_kms.c +++ b/drivers/gpu/drm/xen/xen_drm_front_kms.c @@ -13,6 +13,7 @@ #include <drm/drmP.h> #include <drm/drm_atomic.h> #include <drm/drm_atomic_helper.h> +#include <drm/drm_crtc_helper.h> #include <drm/drm_gem.h> #include <drm/drm_gem_framebuffer_helper.h>

@@ -20,6 +21,12 @@ #include "xen_drm_front_conn.h" #include "xen_drm_front_drv.h"

+/* + * Timeout in ms to wait for frame done event from the backend: + * must be a bit more than IO time-out + */ +#define FRAME_DONE_TO_MS (XEN_DRM_FRONT_WAIT_BACK_MS + 100) + static struct xen_drm_front_drm_pipeline * to_xen_drm_pipeline(struct drm_simple_display_pipe *pipe) { @@ -111,14 +118,18 @@ static void display_enable(struct drm_simple_display_pipe *pipe, fb->format->cpp[0] * 8, xen_drm_front_fb_to_cookie(fb));

- if (ret) + if (ret) { DRM_ERROR("Failed to enable display: %d\n", ret); + pipeline->conn_connected = false; + } }

static void display_disable(struct drm_simple_display_pipe *pipe) { struct xen_drm_front_drm_pipeline *pipeline = to_xen_drm_pipeline(pipe); + struct xen_drm_front_drm_info *drm_info = pipeline->drm_info; + unsigned long flags; int ret;

ret = xen_drm_front_mode_set(pipeline, 0, 0, 0, 0, 0, @@ -126,6 +137,12 @@ static void display_disable(struct drm_simple_display_pipe *pipe) if (ret) DRM_ERROR("Failed to disable display: %d\n", ret);

+ pipeline->conn_connected = true; + + spin_lock_irqsave(&drm_info->front_info->io_lock, flags); + pipeline->pflip_timeout = 0; + spin_unlock_irqrestore(&drm_info->front_info->io_lock, flags); + /* release stalled event if any */ xen_drm_front_kms_send_pending_event(pipeline); } @@ -134,6 +151,12 @@ void xen_drm_front_kms_on_frame_done( struct xen_drm_front_drm_pipeline *pipeline, uint64_t fb_cookie) { + /* + * This already runs in interrupt context, e.g. under + * drm_info->front_info->io_lock + */ + pipeline->pflip_timeout = 0; + xen_drm_front_kms_send_pending_event(pipeline); }

@@ -155,14 +178,21 @@ static bool display_send_page_flip(struct drm_simple_display_pipe *pipe, struct xen_drm_front_drm_pipeline *pipeline = to_xen_drm_pipeline(pipe); struct xen_drm_front_drm_info *drm_info = pipeline->drm_info; + unsigned long flags; int ret;

+ spin_lock_irqsave(&drm_info->front_info->io_lock, flags); + pipeline->pflip_timeout = jiffies + + msecs_to_jiffies(FRAME_DONE_TO_MS); + spin_unlock_irqrestore(&drm_info->front_info->io_lock, flags); + ret = xen_drm_front_page_flip(drm_info->front_info, pipeline->index, xen_drm_front_fb_to_cookie(plane_state->fb)); if (ret) { DRM_ERROR("Failed to send page flip request to backend: %d\n", ret);

+ pipeline->conn_connected = false; /* * Report the flip not handled, so pending event is * sent, unblocking user-space. @@ -185,6 +215,16 @@ static int display_prepare_fb(struct drm_simple_display_pipe *pipe, return drm_gem_fb_prepare_fb(&pipe->plane, plane_state); }

+static int display_check(struct drm_simple_display_pipe *pipe, + struct drm_plane_state *plane_state, + struct drm_crtc_state *crtc_state) +{ + struct xen_drm_front_drm_pipeline *pipeline = + to_xen_drm_pipeline(pipe); + + return pipeline->conn_connected ? 0 : -EINVAL; +} + static void display_update(struct drm_simple_display_pipe *pipe, struct drm_plane_state *old_plane_state) { @@ -222,6 +262,7 @@ static void display_update(struct drm_simple_display_pipe *pipe, static const struct drm_simple_display_pipe_funcs display_funcs = { .enable = display_enable, .disable = display_disable, + .check = display_check, .prepare_fb = display_prepare_fb, .update = display_update, }; @@ -278,5 +319,6 @@ int xen_drm_front_kms_init(struct xen_drm_front_drm_info *drm_info) }

drm_mode_config_reset(dev); + drm_kms_helper_poll_init(dev); return 0; } diff --git a/drivers/gpu/drm/xen/xen_drm_front_kms.h b/drivers/gpu/drm/xen/xen_drm_front_kms.h index 74a2db3d687f..8df23e7942ac 100644 --- a/drivers/gpu/drm/xen/xen_drm_front_kms.h +++ b/drivers/gpu/drm/xen/xen_drm_front_kms.h @@ -19,4 +19,7 @@ void xen_drm_front_kms_on_frame_done( struct xen_drm_front_drm_pipeline *pipeline, uint64_t fb_cookie);

+void xen_drm_front_kms_send_pending_event( + struct xen_drm_front_drm_pipeline *pipeline); + #endif /* __XEN_DRM_FRONT_KMS_H_ */