Merge tag 'drm-misc-next-2022-02-23' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

drm-misc-next for v5.18:

UAPI Changes:

Cross-subsystem Changes:
- Split out panel-lvds and lvds dt bindings .
- Put yes/no on/off disabled/enabled strings in linux/string_helpers.h
  and use it in drivers and tomoyo.
- Clarify dma_fence_chain and dma_fence_array should never include eachother.
- Flatten chains in syncobj's.
- Don't double add in fbdev/defio when page is already enlisted.
- Don't sort deferred-I/O pages by default in fbdev.

Core Changes:
- Fix missing pm_runtime_put_sync in bridge.
- Set modifier support to only linear fb modifier if drivers don't
  advertise support.
- As a result, we remove allow_fb_modifiers.
- Add missing clear for EDID Deep Color Modes in drm_reset_display_info.
- Assorted documentation updates.
- Warn once in drm_clflush if there is no arch support.
- Add missing select for dp helper in drm_panel_edp.
- Assorted small fixes.
- Improve fb-helper's clipping handling.
- Don't dump shmem mmaps in a core dump.
- Add accounting to ttm resource manager, and use it in amdgpu.
- Allow querying the detected eDP panel through debugfs.
- Add helpers for xrgb8888 to 8 and 1 bits gray.
- Improve drm's buddy allocator.
- Add selftests for the buddy allocator.

Driver Changes:
- Add support for nomodeset to a lot of drm drivers.
- Use drm_module_*_driver in a lot of drm drivers.
- Assorted small fixes to bridge/lt9611, v3d, vc4, vmwgfx, mxsfb, nouveau,
  bridge/dw-hdmi, panfrost, lima, ingenic, sprd, bridge/anx7625, ti-sn65dsi86.
- Add bridge/it6505.
- Create DP and DVI-I connectors in ast.
- Assorted nouveau backlight fixes.
- Rework amdgpu reset handling.
- Add dt bindings for ingenic,jz4780-dw-hdmi.
- Support reading edid through aux channel in ingenic.
- Add a drm driver for Solomon SSD130x OLED displays.
- Add simple support for sharp LQ140M1JW46.
- Add more panels to nt35560.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/686ec871-e77f-c230-22e5-9e3bb80f064a@linux.intel.com

4 files changed, 36 insertions, 15 deletions

diff --git a/drivers/video/fbdev/broadsheetfb.c b/drivers/video/fbdev/broadsheetfb.c
index fd66f4d4a621..b9054f658838 100644
--- a/drivers/video/fbdev/broadsheetfb.c
+++ b/drivers/video/fbdev/broadsheetfb.c
@@ -1059,6 +1059,7 @@ static const struct fb_ops broadsheetfb_ops = {
 
 static struct fb_deferred_io broadsheetfb_defio = {
 	.delay		= HZ/4,
+	.sort_pagelist	= true,
 	.deferred_io	= broadsheetfb_dpy_deferred_io,
 };
 
diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
index a591d291b231..98b0f23bf5e2 100644
--- a/drivers/video/fbdev/core/fb_defio.c
+++ b/drivers/video/fbdev/core/fb_defio.c
@@ -59,6 +59,7 @@ static vm_fault_t fb_deferred_io_fault(struct vm_fault *vmf)
 		printk(KERN_ERR "no mapping available\n");
 
 	BUG_ON(!page->mapping);
+	INIT_LIST_HEAD(&page->lru);
 	page->index = vmf->pgoff;
 
 	vmf->page = page;
@@ -95,7 +96,7 @@ static vm_fault_t fb_deferred_io_mkwrite(struct vm_fault *vmf)
 	struct page *page = vmf->page;
 	struct fb_info *info = vmf->vma->vm_private_data;
 	struct fb_deferred_io *fbdefio = info->fbdefio;
-	struct page *cur;
+	struct list_head *pos = &fbdefio->pagelist;
 
 	/* this is a callback we get when userspace first tries to
 	write to the page. we schedule a workqueue. that workqueue
@@ -122,21 +123,38 @@ static vm_fault_t fb_deferred_io_mkwrite(struct vm_fault *vmf)
 	 */
 	lock_page(page);
 
-	/* we loop through the pagelist before adding in order
-	to keep the pagelist sorted */
-	list_for_each_entry(cur, &fbdefio->pagelist, lru) {
-		/* this check is to catch the case where a new
-		process could start writing to the same page
-		through a new pte. this new access can cause the
-		mkwrite even when the original ps's pte is marked
-		writable */
-		if (unlikely(cur == page))
-			goto page_already_added;
-		else if (cur->index > page->index)
-			break;
+	/*
+	 * This check is to catch the case where a new process could start
+	 * writing to the same page through a new PTE. This new access
+	 * can cause a call to .page_mkwrite even if the original process'
+	 * PTE is marked writable.
+	 *
+	 * TODO: The lru field is owned by the page cache; hence the name.
+	 *       We dequeue in fb_deferred_io_work() after flushing the
+	 *       page's content into video memory. Instead of lru, fbdefio
+	 *       should have it's own field.
+	 */
+	if (!list_empty(&page->lru))
+		goto page_already_added;
+
+	if (unlikely(fbdefio->sort_pagelist)) {
+		/*
+		 * We loop through the pagelist before adding in order to
+		 * keep the pagelist sorted. This has significant overhead
+		 * of O(n^2) with n being the number of written pages. If
+		 * possible, drivers should try to work with unsorted page
+		 * lists instead.
+		 */
+		struct page *cur;
+
+		list_for_each_entry(cur, &fbdefio->pagelist, lru) {
+			if (cur->index > page->index)
+				break;
+		}
+		pos = &cur->lru;
 	}
 
-	list_add_tail(&page->lru, &cur->lru);
+	list_add_tail(&page->lru, pos);
 
 page_already_added:
 	mutex_unlock(&fbdefio->lock);
@@ -194,7 +212,7 @@ static void fb_deferred_io_work(struct work_struct *work)
 
 	/* clear the list */
 	list_for_each_safe(node, next, &fbdefio->pagelist) {
-		list_del(node);
+		list_del_init(node);
 	}
 	mutex_unlock(&fbdefio->lock);
 }
diff --git a/drivers/video/fbdev/metronomefb.c b/drivers/video/fbdev/metronomefb.c
index 952826557a0c..af858dd23ea6 100644
--- a/drivers/video/fbdev/metronomefb.c
+++ b/drivers/video/fbdev/metronomefb.c
@@ -568,6 +568,7 @@ static const struct fb_ops metronomefb_ops = {
 
 static struct fb_deferred_io metronomefb_defio = {
 	.delay		= HZ,
+	.sort_pagelist	= true,
 	.deferred_io	= metronomefb_dpy_deferred_io,
 };
 
diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c
index b9cdd02c1000..184bb8433b78 100644
--- a/drivers/video/fbdev/udlfb.c
+++ b/drivers/video/fbdev/udlfb.c
@@ -980,6 +980,7 @@ static int dlfb_ops_open(struct fb_info *info, int user)
 
 		if (fbdefio) {
 			fbdefio->delay = DL_DEFIO_WRITE_DELAY;
+			fbdefio->sort_pagelist = true;
 			fbdefio->deferred_io = dlfb_dpy_deferred_io;
 		}