From patchwork Fri Apr 19 08:29:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Zimmermann X-Patchwork-Id: 13635877 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8DC9B657BE for ; Fri, 19 Apr 2024 08:33:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713515626; cv=none; b=QK9w8suUA16R7VCmrTqtcRJOzkZSjUBvuXQXzJCftIt4zs2mhmYXgOAAK4ratdAQXioeOnBWHkAUIN9Ho4f68XEVMtcHkb6E6CzAkat9gxx2CLpSlolDfxHb/dOqcIYXc7Xq3uAUcSnG36JBBO3WGff4eVM2v7GQc7hV8jaYWw4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713515626; c=relaxed/simple; bh=etmyhMCQu7KbQ9oDIjOmQaSx5qBVBclJDjHk4LlQO6Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VvkXGPUS0ImyfgCQcWYAlNt7OggLBm77l+kQdOiA4GRcVZdc5EYWQwN7kpIBmKAADZr3ucI0yco8kagkLz4+KP46XalVByQmHeXXMOTTGgHdKZdG0p5hDSgeJW2HCBSQAu7Ni5wBxNgAMTiCcLw0K5m618acAR3fsx5JRDDxT5E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 2912B37582; Fri, 19 Apr 2024 08:33:38 +0000 (UTC) Authentication-Results: smtp-out1.suse.de; none Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id EB6DE13984; Fri, 19 Apr 2024 08:33:37 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id eH5iOGEsImb9agAAD6G6ig (envelope-from ); Fri, 19 Apr 2024 08:33:37 +0000 From: Thomas Zimmermann To: javierm@redhat.com, deller@gmx.de, airlied@gmail.com, daniel@ffwll.ch Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, Thomas Zimmermann Subject: [PATCH v3 08/43] drm/fbdev: Add fbdev-shmem Date: Fri, 19 Apr 2024 10:29:01 +0200 Message-ID: <20240419083331.7761-9-tzimmermann@suse.de> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240419083331.7761-1-tzimmermann@suse.de> References: <20240419083331.7761-1-tzimmermann@suse.de> Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spam-Level: X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[] X-Spam-Flag: NO X-Spam-Score: -4.00 X-Rspamd-Queue-Id: 2912B37582 X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Action: no action Add an fbdev emulation for SHMEM-based memory managers. The code is similar to fbdev-generic, but does not require an additional shadow buffer for mmap(). Fbdev-shmem operates directly on the buffer object's SHMEM pages. Fbdev's deferred-I/O mechanism updates the hardware state on write operations. The memory pages of GEM SHMEM cannot be detected by fbdefio. Therefore fbdev-shmem implements the .get_page() hook in struct fb_deferred_io. The fbdefio helpers call this hook to retrieve the page directly from fbdev-shmem instead of trying to detect it internally. v3: - clarify on get_page mechanism in commit description (Javier) v2: - use drm_driver_legacy_fb_format() (Geert) Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas --- drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/drm_fbdev_shmem.c | 316 ++++++++++++++++++++++++++++++ include/drm/drm_fbdev_shmem.h | 15 ++ 3 files changed, 332 insertions(+) create mode 100644 drivers/gpu/drm/drm_fbdev_shmem.c create mode 100644 include/drm/drm_fbdev_shmem.h diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index a73c04d2d7a39..50a2f0cffdac2 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -107,6 +107,7 @@ drm_dma_helper-$(CONFIG_DRM_KMS_HELPER) += drm_fb_dma_helper.o obj-$(CONFIG_DRM_GEM_DMA_HELPER) += drm_dma_helper.o drm_shmem_helper-y := drm_gem_shmem_helper.o +drm_shmem_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fbdev_shmem.o obj-$(CONFIG_DRM_GEM_SHMEM_HELPER) += drm_shmem_helper.o drm_suballoc_helper-y := drm_suballoc.o diff --git a/drivers/gpu/drm/drm_fbdev_shmem.c b/drivers/gpu/drm/drm_fbdev_shmem.c new file mode 100644 index 0000000000000..a85a8a8e2eb8b --- /dev/null +++ b/drivers/gpu/drm/drm_fbdev_shmem.c @@ -0,0 +1,316 @@ +// SPDX-License-Identifier: MIT + +#include + +#include +#include +#include +#include +#include +#include + +#include + +/* + * struct fb_ops + */ + +static int drm_fbdev_shmem_fb_open(struct fb_info *info, int user) +{ + struct drm_fb_helper *fb_helper = info->par; + + /* No need to take a ref for fbcon because it unbinds on unregister */ + if (user && !try_module_get(fb_helper->dev->driver->fops->owner)) + return -ENODEV; + + return 0; +} + +static int drm_fbdev_shmem_fb_release(struct fb_info *info, int user) +{ + struct drm_fb_helper *fb_helper = info->par; + + if (user) + module_put(fb_helper->dev->driver->fops->owner); + + return 0; +} + +FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(drm_fbdev_shmem, + drm_fb_helper_damage_range, + drm_fb_helper_damage_area); + +static int drm_fbdev_shmem_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) +{ + struct drm_fb_helper *fb_helper = info->par; + struct drm_framebuffer *fb = fb_helper->fb; + struct drm_gem_object *obj = drm_gem_fb_get_obj(fb, 0); + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + if (shmem->map_wc) + vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); + + return fb_deferred_io_mmap(info, vma); +} + +static void drm_fbdev_shmem_fb_destroy(struct fb_info *info) +{ + struct drm_fb_helper *fb_helper = info->par; + + if (!fb_helper->dev) + return; + + drm_fb_helper_fini(fb_helper); + + drm_client_buffer_vunmap(fb_helper->buffer); + drm_client_framebuffer_delete(fb_helper->buffer); + drm_client_release(&fb_helper->client); + drm_fb_helper_unprepare(fb_helper); + kfree(fb_helper); +} + +static const struct fb_ops drm_fbdev_shmem_fb_ops = { + .owner = THIS_MODULE, + .fb_open = drm_fbdev_shmem_fb_open, + .fb_release = drm_fbdev_shmem_fb_release, + __FB_DEFAULT_DEFERRED_OPS_RDWR(drm_fbdev_shmem), + DRM_FB_HELPER_DEFAULT_OPS, + __FB_DEFAULT_DEFERRED_OPS_DRAW(drm_fbdev_shmem), + .fb_mmap = drm_fbdev_shmem_fb_mmap, + .fb_destroy = drm_fbdev_shmem_fb_destroy, +}; + +static struct page *drm_fbdev_shmem_get_page(struct fb_info *info, unsigned long offset) +{ + struct drm_fb_helper *fb_helper = info->par; + struct drm_framebuffer *fb = fb_helper->fb; + struct drm_gem_object *obj = drm_gem_fb_get_obj(fb, 0); + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + unsigned int i = offset >> PAGE_SHIFT; + struct page *page; + + if (fb_WARN_ON_ONCE(info, offset > obj->size)) + return NULL; + + page = shmem->pages[i]; // protected by active vmap + if (page) + get_page(page); + fb_WARN_ON_ONCE(info, !page); + + return page; +} + +/* + * struct drm_fb_helper + */ + +static int drm_fbdev_shmem_helper_fb_probe(struct drm_fb_helper *fb_helper, + struct drm_fb_helper_surface_size *sizes) +{ + struct drm_client_dev *client = &fb_helper->client; + struct drm_device *dev = fb_helper->dev; + struct drm_client_buffer *buffer; + struct drm_gem_shmem_object *shmem; + struct drm_framebuffer *fb; + struct fb_info *info; + u32 format; + struct iosys_map map; + int ret; + + drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n", + sizes->surface_width, sizes->surface_height, + sizes->surface_bpp); + + format = drm_driver_legacy_fb_format(dev, sizes->surface_bpp, sizes->surface_depth); + buffer = drm_client_framebuffer_create(client, sizes->surface_width, + sizes->surface_height, format); + if (IS_ERR(buffer)) + return PTR_ERR(buffer); + shmem = to_drm_gem_shmem_obj(buffer->gem); + + fb = buffer->fb; + + ret = drm_client_buffer_vmap(buffer, &map); + if (ret) { + goto err_drm_client_buffer_delete; + } else if (drm_WARN_ON(dev, map.is_iomem)) { + ret = -ENODEV; /* I/O memory not supported; use generic emulation */ + goto err_drm_client_buffer_delete; + } + + fb_helper->buffer = buffer; + fb_helper->fb = fb; + + info = drm_fb_helper_alloc_info(fb_helper); + if (IS_ERR(info)) { + ret = PTR_ERR(info); + goto err_drm_client_buffer_vunmap; + } + + drm_fb_helper_fill_info(info, fb_helper, sizes); + + info->fbops = &drm_fbdev_shmem_fb_ops; + + /* screen */ + info->flags |= FBINFO_VIRTFB; /* system memory */ + if (!shmem->map_wc) + info->flags |= FBINFO_READS_FAST; /* signal caching */ + info->screen_size = sizes->surface_height * fb->pitches[0]; + info->screen_buffer = map.vaddr; + info->fix.smem_len = info->screen_size; + + /* deferred I/O */ + fb_helper->fbdefio.delay = HZ / 20; + fb_helper->fbdefio.get_page = drm_fbdev_shmem_get_page; + fb_helper->fbdefio.deferred_io = drm_fb_helper_deferred_io; + + info->fbdefio = &fb_helper->fbdefio; + ret = fb_deferred_io_init(info); + if (ret) + goto err_drm_fb_helper_release_info; + + return 0; + +err_drm_fb_helper_release_info: + drm_fb_helper_release_info(fb_helper); +err_drm_client_buffer_vunmap: + fb_helper->fb = NULL; + fb_helper->buffer = NULL; + drm_client_buffer_vunmap(buffer); +err_drm_client_buffer_delete: + drm_client_framebuffer_delete(buffer); + return ret; +} + +static int drm_fbdev_shmem_helper_fb_dirty(struct drm_fb_helper *helper, + struct drm_clip_rect *clip) +{ + struct drm_device *dev = helper->dev; + int ret; + + /* Call damage handlers only if necessary */ + if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2)) + return 0; + + if (helper->fb->funcs->dirty) { + ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1); + if (drm_WARN_ONCE(dev, ret, "Dirty helper failed: ret=%d\n", ret)) + return ret; + } + + return 0; +} + +static const struct drm_fb_helper_funcs drm_fbdev_shmem_helper_funcs = { + .fb_probe = drm_fbdev_shmem_helper_fb_probe, + .fb_dirty = drm_fbdev_shmem_helper_fb_dirty, +}; + +/* + * struct drm_client_funcs + */ + +static void drm_fbdev_shmem_client_unregister(struct drm_client_dev *client) +{ + struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); + + if (fb_helper->info) { + drm_fb_helper_unregister_info(fb_helper); + } else { + drm_client_release(&fb_helper->client); + drm_fb_helper_unprepare(fb_helper); + kfree(fb_helper); + } +} + +static int drm_fbdev_shmem_client_restore(struct drm_client_dev *client) +{ + drm_fb_helper_lastclose(client->dev); + + return 0; +} + +static int drm_fbdev_shmem_client_hotplug(struct drm_client_dev *client) +{ + struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client); + struct drm_device *dev = client->dev; + int ret; + + if (dev->fb_helper) + return drm_fb_helper_hotplug_event(dev->fb_helper); + + ret = drm_fb_helper_init(dev, fb_helper); + if (ret) + goto err_drm_err; + + if (!drm_drv_uses_atomic_modeset(dev)) + drm_helper_disable_unused_functions(dev); + + ret = drm_fb_helper_initial_config(fb_helper); + if (ret) + goto err_drm_fb_helper_fini; + + return 0; + +err_drm_fb_helper_fini: + drm_fb_helper_fini(fb_helper); +err_drm_err: + drm_err(dev, "fbdev-shmem: Failed to setup emulation (ret=%d)\n", ret); + return ret; +} + +static const struct drm_client_funcs drm_fbdev_shmem_client_funcs = { + .owner = THIS_MODULE, + .unregister = drm_fbdev_shmem_client_unregister, + .restore = drm_fbdev_shmem_client_restore, + .hotplug = drm_fbdev_shmem_client_hotplug, +}; + +/** + * drm_fbdev_shmem_setup() - Setup fbdev emulation for GEM SHMEM helpers + * @dev: DRM device + * @preferred_bpp: Preferred bits per pixel for the device. + * 32 is used if this is zero. + * + * This function sets up fbdev emulation for GEM DMA drivers that support + * dumb buffers with a virtual address and that can be mmap'ed. + * drm_fbdev_shmem_setup() shall be called after the DRM driver registered + * the new DRM device with drm_dev_register(). + * + * Restore, hotplug events and teardown are all taken care of. Drivers that do + * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves. + * Simple drivers might use drm_mode_config_helper_suspend(). + * + * This function is safe to call even when there are no connectors present. + * Setup will be retried on the next hotplug event. + * + * The fbdev is destroyed by drm_dev_unregister(). + */ +void drm_fbdev_shmem_setup(struct drm_device *dev, unsigned int preferred_bpp) +{ + struct drm_fb_helper *fb_helper; + int ret; + + drm_WARN(dev, !dev->registered, "Device has not been registered.\n"); + drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n"); + + fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL); + if (!fb_helper) + return; + drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_shmem_helper_funcs); + + ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_shmem_client_funcs); + if (ret) { + drm_err(dev, "Failed to register client: %d\n", ret); + goto err_drm_client_init; + } + + drm_client_register(&fb_helper->client); + + return; + +err_drm_client_init: + drm_fb_helper_unprepare(fb_helper); + kfree(fb_helper); +} +EXPORT_SYMBOL(drm_fbdev_shmem_setup); diff --git a/include/drm/drm_fbdev_shmem.h b/include/drm/drm_fbdev_shmem.h new file mode 100644 index 0000000000000..fb43cadd1950c --- /dev/null +++ b/include/drm/drm_fbdev_shmem.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: MIT */ + +#ifndef DRM_FBDEV_SHMEM_H +#define DRM_FBDEV_SHMEM_H + +struct drm_device; + +#ifdef CONFIG_DRM_FBDEV_EMULATION +void drm_fbdev_shmem_setup(struct drm_device *dev, unsigned int preferred_bpp); +#else +static inline void drm_fbdev_shmem_setup(struct drm_device *dev, unsigned int preferred_bpp) +{ } +#endif + +#endif