[PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Thomas Zimmermann]

DRM client buffers are permanently mapped throughout their lifetime. This
prevents us from using generic framebuffer emulation for devices with
small dedicated video memory, such as ast or mgag200. With fb buffers
permanently mapped, such devices often won't have enougth space left to
display other content (e.g., X11).

This patch set introduces unmappable DRM client buffers for framebuffer
emulation with shadow buffers. While the shadow buffer remains in system
memory permanently, the respective buffer object will only be mapped briefly
during updates from the shadow buffer. Hence, the driver can relocate he
buffer object among memory regions as needed.

The default behoviour for DRM client buffers is still to be permanently
mapped.

The patch set converts ast and mgag200 to generic framebuffer emulation
and removes a large amount of framebuffer code from these drivers. For
bochs, a problem was reported where the driver could not display the console
because it was pinned in system memory. [1] The patch set fixes this bug
by converting bochs to use the shadow fb.

The patch set has been tested on ast and mga200 HW.

[1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html

Thomas Zimmermann (5):
  drm/client: Support unmapping of DRM client buffers
  drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
  drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
  drm/bochs: Use shadow buffer for bochs framebuffer console
  drm/mgag200: Replace struct mga_fbdev with generic framebuffer
    emulation

 drivers/gpu/drm/ast/Makefile           |   2 +-
 drivers/gpu/drm/ast/ast_drv.c          |  22 +-
 drivers/gpu/drm/ast/ast_drv.h          |  17 --
 drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
 drivers/gpu/drm/ast/ast_main.c         |  30 ++-
 drivers/gpu/drm/ast/ast_mode.c         |  21 --
 drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
 drivers/gpu/drm/drm_client.c           |  71 ++++-
 drivers/gpu/drm/drm_fb_helper.c        |  14 +-
 drivers/gpu/drm/mgag200/Makefile       |   2 +-
 drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
 drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
 drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
 drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
 include/drm/drm_client.h               |   3 +
 15 files changed, 154 insertions(+), 787 deletions(-)
 delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
 delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c

--
2.21.0

[PATCH 1/5] drm/client: Support unmapping of DRM client buffers

[Thomas Zimmermann]

DRM clients, such as the fbdev emulation, have their buffer objects
mapped by default. Mapping a buffer implicitly prevents its relocation.
Hence, the buffer may permanently consume video memory while it's
allocated. This is a problem for drivers of low-memory devices, such as
ast, mgag200 or older framebuffer hardware, which will then not have
enough memory to display other content (e.g., X11).

This patch introduces drm_client_buffer_vmap() and _vunmap(). Internal
DRM clients can use these functions to unmap and remap buffer objects
as needed.

There's no reference counting for vmap operations. Callers are expected
to either keep buffers mapped (as it is now), or call vmap and vunmap
in pairs around code that accesses the mapped memory.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/drm_client.c | 71 +++++++++++++++++++++++++++++++-----
 include/drm/drm_client.h     |  3 ++
 2 files changed, 64 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index 410572f14257..d04660c4470a 100644
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -235,7 +235,8 @@ static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
 {
 	struct drm_device *dev = buffer->client->dev;
 
-	drm_gem_vunmap(buffer->gem, buffer->vaddr);
+	if (buffer->vaddr)
+		drm_gem_vunmap(buffer->gem, buffer->vaddr);
 
 	if (buffer->gem)
 		drm_gem_object_put_unlocked(buffer->gem);
@@ -281,6 +282,43 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
 
 	buffer->gem = obj;
 
+	vaddr = drm_client_buffer_vmap(buffer);
+	if (IS_ERR(vaddr)) {
+		ret = PTR_ERR(vaddr);
+		goto err_delete;
+	}
+
+	return buffer;
+
+err_delete:
+	drm_client_buffer_delete(buffer);
+
+	return ERR_PTR(ret);
+}
+
+/**
+ * drm_client_buffer_vmap - Map DRM client buffer into address space
+ * @buffer: DRM client buffer
+ *
+ * This function maps a client buffer into kernel address space. If the
+ * buffer is already mapped, it returns the mapping's address.
+ *
+ * Client buffer mappings are not ref'counted. Each call to
+ * drm_client_buffer_vmap() should be followed by a call to
+ * drm_client_buffer_vunmap(); or the client buffer should be mapped
+ * throughout its lifetime. The latter is the default.
+ *
+ * Returns:
+ *	The mapped memory's address
+ */
+void *
+drm_client_buffer_vmap(struct drm_client_buffer *buffer)
+{
+	void *vaddr;
+
+	if (buffer->vaddr)
+		return buffer->vaddr;
+
 	/*
 	 * FIXME: The dependency on GEM here isn't required, we could
 	 * convert the driver handle to a dma-buf instead and use the
@@ -289,21 +327,34 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
 	 * fd_install step out of the driver backend hooks, to make that
 	 * final step optional for internal users.
 	 */
-	vaddr = drm_gem_vmap(obj);
-	if (IS_ERR(vaddr)) {
-		ret = PTR_ERR(vaddr);
-		goto err_delete;
-	}
+	vaddr = drm_gem_vmap(buffer->gem);
+	if (IS_ERR(vaddr))
+		return vaddr;
 
 	buffer->vaddr = vaddr;
 
-	return buffer;
+	return vaddr;
+}
+EXPORT_SYMBOL(drm_client_buffer_vmap);
 
-err_delete:
-	drm_client_buffer_delete(buffer);
+/**
+ * drm_client_buffer_vunmap - Unmap DRM client buffer
+ * @buffer: DRM client buffer
+ *
+ * This function removes a client buffer's memory mmapping. This
+ * function is only required by clients that manage their buffers
+ * by themselves. By default, DRM client buffers are mapped throughout
+ * their entire lifetime.
+ */
+void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
+{
+	if (!buffer->vaddr)
+		return;
 
-	return ERR_PTR(ret);
+	drm_gem_vunmap(buffer->gem, buffer->vaddr);
+	buffer->vaddr = NULL;
 }
+EXPORT_SYMBOL(drm_client_buffer_vunmap);
 
 static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
 {
diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
index 72d51d1e9dd9..e1db1d9da0bf 100644
--- a/include/drm/drm_client.h
+++ b/include/drm/drm_client.h
@@ -149,6 +149,9 @@ struct drm_client_buffer {
 struct drm_client_buffer *
 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format);
 void drm_client_framebuffer_delete(struct drm_client_buffer *buffer);
+void *
+drm_client_buffer_vmap(struct drm_client_buffer *buffer);
+void drm_client_buffer_vunmap(struct drm_client_buffer *buffer);
 
 int drm_client_modeset_create(struct drm_client_dev *client);
 void drm_client_modeset_free(struct drm_client_dev *client);
-- 
2.21.0

[PATCH 1/5] drm/client: Support unmapping of DRM client buffers

[Thomas Zimmermann]

DRM clients, such as the fbdev emulation, have their buffer objects
mapped by default. Mapping a buffer implicitly prevents its relocation.
Hence, the buffer may permanently consume video memory while it's
allocated. This is a problem for drivers of low-memory devices, such as
ast, mgag200 or older framebuffer hardware, which will then not have
enough memory to display other content (e.g., X11).

This patch introduces drm_client_buffer_vmap() and _vunmap(). Internal
DRM clients can use these functions to unmap and remap buffer objects
as needed.

There's no reference counting for vmap operations. Callers are expected
to either keep buffers mapped (as it is now), or call vmap and vunmap
in pairs around code that accesses the mapped memory.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/drm_client.c | 71 +++++++++++++++++++++++++++++++-----
 include/drm/drm_client.h     |  3 ++
 2 files changed, 64 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index 410572f14257..d04660c4470a 100644
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -235,7 +235,8 @@ static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
 {
 	struct drm_device *dev = buffer->client->dev;
 
-	drm_gem_vunmap(buffer->gem, buffer->vaddr);
+	if (buffer->vaddr)
+		drm_gem_vunmap(buffer->gem, buffer->vaddr);
 
 	if (buffer->gem)
 		drm_gem_object_put_unlocked(buffer->gem);
@@ -281,6 +282,43 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
 
 	buffer->gem = obj;
 
+	vaddr = drm_client_buffer_vmap(buffer);
+	if (IS_ERR(vaddr)) {
+		ret = PTR_ERR(vaddr);
+		goto err_delete;
+	}
+
+	return buffer;
+
+err_delete:
+	drm_client_buffer_delete(buffer);
+
+	return ERR_PTR(ret);
+}
+
+/**
+ * drm_client_buffer_vmap - Map DRM client buffer into address space
+ * @buffer: DRM client buffer
+ *
+ * This function maps a client buffer into kernel address space. If the
+ * buffer is already mapped, it returns the mapping's address.
+ *
+ * Client buffer mappings are not ref'counted. Each call to
+ * drm_client_buffer_vmap() should be followed by a call to
+ * drm_client_buffer_vunmap(); or the client buffer should be mapped
+ * throughout its lifetime. The latter is the default.
+ *
+ * Returns:
+ *	The mapped memory's address
+ */
+void *
+drm_client_buffer_vmap(struct drm_client_buffer *buffer)
+{
+	void *vaddr;
+
+	if (buffer->vaddr)
+		return buffer->vaddr;
+
 	/*
 	 * FIXME: The dependency on GEM here isn't required, we could
 	 * convert the driver handle to a dma-buf instead and use the
@@ -289,21 +327,34 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
 	 * fd_install step out of the driver backend hooks, to make that
 	 * final step optional for internal users.
 	 */
-	vaddr = drm_gem_vmap(obj);
-	if (IS_ERR(vaddr)) {
-		ret = PTR_ERR(vaddr);
-		goto err_delete;
-	}
+	vaddr = drm_gem_vmap(buffer->gem);
+	if (IS_ERR(vaddr))
+		return vaddr;
 
 	buffer->vaddr = vaddr;
 
-	return buffer;
+	return vaddr;
+}
+EXPORT_SYMBOL(drm_client_buffer_vmap);
 
-err_delete:
-	drm_client_buffer_delete(buffer);
+/**
+ * drm_client_buffer_vunmap - Unmap DRM client buffer
+ * @buffer: DRM client buffer
+ *
+ * This function removes a client buffer's memory mmapping. This
+ * function is only required by clients that manage their buffers
+ * by themselves. By default, DRM client buffers are mapped throughout
+ * their entire lifetime.
+ */
+void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
+{
+	if (!buffer->vaddr)
+		return;
 
-	return ERR_PTR(ret);
+	drm_gem_vunmap(buffer->gem, buffer->vaddr);
+	buffer->vaddr = NULL;
 }
+EXPORT_SYMBOL(drm_client_buffer_vunmap);
 
 static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
 {
diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
index 72d51d1e9dd9..e1db1d9da0bf 100644
--- a/include/drm/drm_client.h
+++ b/include/drm/drm_client.h
@@ -149,6 +149,9 @@ struct drm_client_buffer {
 struct drm_client_buffer *
 drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format);
 void drm_client_framebuffer_delete(struct drm_client_buffer *buffer);
+void *
+drm_client_buffer_vmap(struct drm_client_buffer *buffer);
+void drm_client_buffer_vunmap(struct drm_client_buffer *buffer);
 
 int drm_client_modeset_create(struct drm_client_dev *client);
 void drm_client_modeset_free(struct drm_client_dev *client);
-- 
2.21.0

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[PATCH 2/5] drm/fb-helper: Unmap BO for shadow-buffered framebuffer console

[Thomas Zimmermann]

The shadow-buffered framebuffer console only needs the buffer object
to be mapped during updates. While not being updated from the shadow
buffer, the buffer object can remain unmapped.

An unmapped buffer object can be evicted to system memory and does
not consume video ram until displayed. This allows to use generic fbdev
emulation with drivers for low-memory devices, such as ast and mgag200.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/drm_fb_helper.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 1984e5c54d58..2a6538f229e3 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -403,6 +403,7 @@ static void drm_fb_helper_dirty_work(struct work_struct *work)
 	struct drm_clip_rect *clip = &helper->dirty_clip;
 	struct drm_clip_rect clip_copy;
 	unsigned long flags;
+	void *vaddr;
 
 	spin_lock_irqsave(&helper->dirty_lock, flags);
 	clip_copy = *clip;
@@ -412,10 +413,18 @@ static void drm_fb_helper_dirty_work(struct work_struct *work)
 
 	/* call dirty callback only when it has been really touched */
 	if (clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2) {
+
 		/* Generic fbdev uses a shadow buffer */
-		if (helper->buffer)
+		if (helper->buffer) {
+			vaddr = drm_client_buffer_vmap(helper->buffer);
+			if (IS_ERR(vaddr))
+				return;
 			drm_fb_helper_dirty_blit_real(helper, &clip_copy);
+		}
 		helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
+
+		if (helper->buffer)
+			drm_client_buffer_vunmap(helper->buffer);
 	}
 }
 
@@ -2231,6 +2240,9 @@ int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
 		fbi->fbdefio = &drm_fbdev_defio;
 
 		fb_deferred_io_init(fbi);
+
+		/* unmapped by default */
+		drm_client_buffer_vunmap(fb_helper->buffer);
 	}
 
 	return 0;
-- 
2.21.0

[PATCH 2/5] drm/fb-helper: Unmap BO for shadow-buffered framebuffer console

[Thomas Zimmermann]

The shadow-buffered framebuffer console only needs the buffer object
to be mapped during updates. While not being updated from the shadow
buffer, the buffer object can remain unmapped.

An unmapped buffer object can be evicted to system memory and does
not consume video ram until displayed. This allows to use generic fbdev
emulation with drivers for low-memory devices, such as ast and mgag200.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/drm_fb_helper.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 1984e5c54d58..2a6538f229e3 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -403,6 +403,7 @@ static void drm_fb_helper_dirty_work(struct work_struct *work)
 	struct drm_clip_rect *clip = &helper->dirty_clip;
 	struct drm_clip_rect clip_copy;
 	unsigned long flags;
+	void *vaddr;
 
 	spin_lock_irqsave(&helper->dirty_lock, flags);
 	clip_copy = *clip;
@@ -412,10 +413,18 @@ static void drm_fb_helper_dirty_work(struct work_struct *work)
 
 	/* call dirty callback only when it has been really touched */
 	if (clip_copy.x1 < clip_copy.x2 && clip_copy.y1 < clip_copy.y2) {
+
 		/* Generic fbdev uses a shadow buffer */
-		if (helper->buffer)
+		if (helper->buffer) {
+			vaddr = drm_client_buffer_vmap(helper->buffer);
+			if (IS_ERR(vaddr))
+				return;
 			drm_fb_helper_dirty_blit_real(helper, &clip_copy);
+		}
 		helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
+
+		if (helper->buffer)
+			drm_client_buffer_vunmap(helper->buffer);
 	}
 }
 
@@ -2231,6 +2240,9 @@ int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
 		fbi->fbdefio = &drm_fbdev_defio;
 
 		fb_deferred_io_init(fbi);
+
+		/* unmapped by default */
+		drm_client_buffer_vunmap(fb_helper->buffer);
 	}
 
 	return 0;
-- 
2.21.0

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[PATCH 3/5] drm/ast: Replace struct ast_fbdev with generic framebuffer emulation

[Thomas Zimmermann]

This patch replaces ast's framebuffer console with DRM's generic
implememtation. All respective code is being removed from the driver.

The console is set up with a shadow buffer. The actual buffer object is
not permanently pinned in video ram, but just another buffer object that
the driver moves in and out of vram as necessary. The driver's function
ast_crtc_do_set_base() used to contain special handling for the framebuffer
console. With the new generic framebuffer, the driver does not need this
code an longer.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/ast/Makefile   |   2 +-
 drivers/gpu/drm/ast/ast_drv.c  |  22 ++-
 drivers/gpu/drm/ast/ast_drv.h  |  17 --
 drivers/gpu/drm/ast/ast_fb.c   | 341 ---------------------------------
 drivers/gpu/drm/ast/ast_main.c |  30 ++-
 drivers/gpu/drm/ast/ast_mode.c |  21 --
 6 files changed, 41 insertions(+), 392 deletions(-)
 delete mode 100644 drivers/gpu/drm/ast/ast_fb.c

diff --git a/drivers/gpu/drm/ast/Makefile b/drivers/gpu/drm/ast/Makefile
index b086dae17013..561f7c4199e4 100644
--- a/drivers/gpu/drm/ast/Makefile
+++ b/drivers/gpu/drm/ast/Makefile
@@ -3,6 +3,6 @@
 # Makefile for the drm device driver.  This driver provides support for the
 # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
 
-ast-y := ast_drv.o ast_main.o ast_mode.o ast_fb.o ast_ttm.o ast_post.o ast_dp501.o
+ast-y := ast_drv.o ast_main.o ast_mode.o ast_ttm.o ast_post.o ast_dp501.o
 
 obj-$(CONFIG_DRM_AST) := ast.o
diff --git a/drivers/gpu/drm/ast/ast_drv.c b/drivers/gpu/drm/ast/ast_drv.c
index 3811997e78c4..75f55ac1a218 100644
--- a/drivers/gpu/drm/ast/ast_drv.c
+++ b/drivers/gpu/drm/ast/ast_drv.c
@@ -103,25 +103,29 @@ static int ast_drm_freeze(struct drm_device *dev)
 
 	pci_save_state(dev->pdev);
 
-	console_lock();
-	ast_fbdev_set_suspend(dev, 1);
-	console_unlock();
+	if (dev->fb_helper) {
+		console_lock();
+		drm_fb_helper_set_suspend(dev->fb_helper, 1);
+		console_unlock();
+	}
+
 	return 0;
 }
 
 static int ast_drm_thaw(struct drm_device *dev)
 {
-	int error = 0;
-
 	ast_post_gpu(dev);
 
 	drm_mode_config_reset(dev);
 	drm_helper_resume_force_mode(dev);
 
-	console_lock();
-	ast_fbdev_set_suspend(dev, 0);
-	console_unlock();
-	return error;
+	if (dev->fb_helper) {
+		console_lock();
+		drm_fb_helper_set_suspend(dev->fb_helper, 0);
+		console_unlock();
+	}
+
+	return 0;
 }
 
 static int ast_drm_resume(struct drm_device *dev)
diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index ca794a3fcf8f..907d7480b7ba 100644
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -81,8 +81,6 @@ enum ast_tx_chip {
 #define AST_DRAM_4Gx16   7
 #define AST_DRAM_8Gx16   8
 
-struct ast_fbdev;
-
 struct ast_private {
 	struct drm_device *dev;
 
@@ -96,8 +94,6 @@ struct ast_private {
 	uint32_t mclk;
 	uint32_t vram_size;
 
-	struct ast_fbdev *fbdev;
-
 	int fb_mtrr;
 
 	struct drm_gem_object *cursor_cache;
@@ -239,14 +235,6 @@ struct ast_encoder {
 	struct drm_encoder base;
 };
 
-struct ast_fbdev {
-	struct drm_fb_helper helper; /* must be first */
-	void *sysram;
-	int size;
-	int x1, y1, x2, y2; /* dirty rect */
-	spinlock_t dirty_lock;
-};
-
 #define to_ast_crtc(x) container_of(x, struct ast_crtc, base)
 #define to_ast_connector(x) container_of(x, struct ast_connector, base)
 #define to_ast_encoder(x) container_of(x, struct ast_encoder, base)
@@ -289,11 +277,6 @@ struct ast_vbios_mode_info {
 extern int ast_mode_init(struct drm_device *dev);
 extern void ast_mode_fini(struct drm_device *dev);
 
-int ast_fbdev_init(struct drm_device *dev);
-void ast_fbdev_fini(struct drm_device *dev);
-void ast_fbdev_set_suspend(struct drm_device *dev, int state);
-void ast_fbdev_set_base(struct ast_private *ast, unsigned long gpu_addr);
-
 #define AST_MM_ALIGN_SHIFT 4
 #define AST_MM_ALIGN_MASK ((1 << AST_MM_ALIGN_SHIFT) - 1)
 
diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c
deleted file mode 100644
index a849e58b40bc..000000000000
--- a/drivers/gpu/drm/ast/ast_fb.c
+++ /dev/null
@@ -1,341 +0,0 @@
-/*
- * Copyright 2012 Red Hat Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the
- * "Software"), to deal in the Software without restriction, including
- * without limitation the rights to use, copy, modify, merge, publish,
- * distribute, sub license, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to
- * the following conditions:
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
- * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
- * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
- * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
- * USE OR OTHER DEALINGS IN THE SOFTWARE.
- *
- * The above copyright notice and this permission notice (including the
- * next paragraph) shall be included in all copies or substantial portions
- * of the Software.
- *
- */
-/*
- * Authors: Dave Airlie <airlied@redhat.com>
- */
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/mm.h>
-#include <linux/tty.h>
-#include <linux/sysrq.h>
-#include <linux/delay.h>
-#include <linux/init.h>
-
-
-#include <drm/drmP.h>
-#include <drm/drm_crtc.h>
-#include <drm/drm_crtc_helper.h>
-#include <drm/drm_fb_helper.h>
-#include <drm/drm_gem_framebuffer_helper.h>
-#include <drm/drm_util.h>
-
-#include "ast_drv.h"
-
-static void ast_dirty_update(struct ast_fbdev *afbdev,
-			     int x, int y, int width, int height)
-{
-	int i;
-	struct drm_gem_vram_object *gbo;
-	int src_offset, dst_offset;
-	int ret;
-	u8 *dst;
-	bool unmap = false;
-	bool store_for_later = false;
-	int x2, y2;
-	unsigned long flags;
-	struct drm_framebuffer *fb = afbdev->helper.fb;
-	int bpp = fb->format->cpp[0];
-
-	gbo = drm_gem_vram_of_gem(fb->obj[0]);
-
-	if (drm_can_sleep()) {
-		/* We pin the BO so it won't be moved during the
-		 * update. The actual location, video RAM or system
-		 * memory, is not important.
-		 */
-		ret = drm_gem_vram_pin(gbo, 0);
-		if (ret) {
-			if (ret != -EBUSY)
-				return;
-			store_for_later = true;
-		}
-	} else {
-		store_for_later = true;
-	}
-
-	x2 = x + width - 1;
-	y2 = y + height - 1;
-	spin_lock_irqsave(&afbdev->dirty_lock, flags);
-
-	if (afbdev->y1 < y)
-		y = afbdev->y1;
-	if (afbdev->y2 > y2)
-		y2 = afbdev->y2;
-	if (afbdev->x1 < x)
-		x = afbdev->x1;
-	if (afbdev->x2 > x2)
-		x2 = afbdev->x2;
-
-	if (store_for_later) {
-		afbdev->x1 = x;
-		afbdev->x2 = x2;
-		afbdev->y1 = y;
-		afbdev->y2 = y2;
-		spin_unlock_irqrestore(&afbdev->dirty_lock, flags);
-		return;
-	}
-
-	afbdev->x1 = afbdev->y1 = INT_MAX;
-	afbdev->x2 = afbdev->y2 = 0;
-	spin_unlock_irqrestore(&afbdev->dirty_lock, flags);
-
-	dst = drm_gem_vram_kmap(gbo, false, NULL);
-	if (IS_ERR(dst)) {
-		DRM_ERROR("failed to kmap fb updates\n");
-		goto out;
-	} else if (!dst) {
-		dst = drm_gem_vram_kmap(gbo, true, NULL);
-		if (IS_ERR(dst)) {
-			DRM_ERROR("failed to kmap fb updates\n");
-			goto out;
-		}
-		unmap = true;
-	}
-
-	for (i = y; i <= y2; i++) {
-		/* assume equal stride for now */
-		src_offset = dst_offset = i * fb->pitches[0] + (x * bpp);
-		memcpy_toio(dst + dst_offset, afbdev->sysram + src_offset,
-			    (x2 - x + 1) * bpp);
-	}
-
-	if (unmap)
-		drm_gem_vram_kunmap(gbo);
-
-out:
-	drm_gem_vram_unpin(gbo);
-}
-
-static void ast_fillrect(struct fb_info *info,
-			 const struct fb_fillrect *rect)
-{
-	struct ast_fbdev *afbdev = info->par;
-	drm_fb_helper_sys_fillrect(info, rect);
-	ast_dirty_update(afbdev, rect->dx, rect->dy, rect->width,
-			 rect->height);
-}
-
-static void ast_copyarea(struct fb_info *info,
-			 const struct fb_copyarea *area)
-{
-	struct ast_fbdev *afbdev = info->par;
-	drm_fb_helper_sys_copyarea(info, area);
-	ast_dirty_update(afbdev, area->dx, area->dy, area->width,
-			 area->height);
-}
-
-static void ast_imageblit(struct fb_info *info,
-			  const struct fb_image *image)
-{
-	struct ast_fbdev *afbdev = info->par;
-	drm_fb_helper_sys_imageblit(info, image);
-	ast_dirty_update(afbdev, image->dx, image->dy, image->width,
-			 image->height);
-}
-
-static struct fb_ops astfb_ops = {
-	.owner = THIS_MODULE,
-	.fb_check_var = drm_fb_helper_check_var,
-	.fb_set_par = drm_fb_helper_set_par,
-	.fb_fillrect = ast_fillrect,
-	.fb_copyarea = ast_copyarea,
-	.fb_imageblit = ast_imageblit,
-	.fb_pan_display = drm_fb_helper_pan_display,
-	.fb_blank = drm_fb_helper_blank,
-	.fb_setcmap = drm_fb_helper_setcmap,
-};
-
-static int astfb_create_object(struct ast_fbdev *afbdev,
-			       const struct drm_mode_fb_cmd2 *mode_cmd,
-			       struct drm_gem_object **gobj_p)
-{
-	struct drm_device *dev = afbdev->helper.dev;
-	u32 size;
-	struct drm_gem_object *gobj;
-	int ret = 0;
-
-	size = mode_cmd->pitches[0] * mode_cmd->height;
-	ret = ast_gem_create(dev, size, true, &gobj);
-	if (ret)
-		return ret;
-
-	*gobj_p = gobj;
-	return ret;
-}
-
-static int astfb_create(struct drm_fb_helper *helper,
-			struct drm_fb_helper_surface_size *sizes)
-{
-	struct ast_fbdev *afbdev =
-		container_of(helper, struct ast_fbdev, helper);
-	struct drm_device *dev = afbdev->helper.dev;
-	struct drm_mode_fb_cmd2 mode_cmd;
-	struct drm_framebuffer *fb;
-	struct fb_info *info;
-	int size, ret;
-	void *sysram;
-	struct drm_gem_object *gobj = NULL;
-	mode_cmd.width = sizes->surface_width;
-	mode_cmd.height = sizes->surface_height;
-	mode_cmd.pitches[0] = mode_cmd.width * ((sizes->surface_bpp + 7)/8);
-
-	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
-							  sizes->surface_depth);
-
-	size = mode_cmd.pitches[0] * mode_cmd.height;
-
-	ret = astfb_create_object(afbdev, &mode_cmd, &gobj);
-	if (ret) {
-		DRM_ERROR("failed to create fbcon backing object %d\n", ret);
-		return ret;
-	}
-
-	sysram = vmalloc(size);
-	if (!sysram)
-		return -ENOMEM;
-
-	info = drm_fb_helper_alloc_fbi(helper);
-	if (IS_ERR(info)) {
-		ret = PTR_ERR(info);
-		goto out;
-	}
-	fb = drm_gem_fbdev_fb_create(dev, sizes, 0, gobj, NULL);
-	if (IS_ERR(fb)) {
-		ret = PTR_ERR(fb);
-		goto out;
-	}
-
-	afbdev->sysram = sysram;
-	afbdev->size = size;
-
-	afbdev->helper.fb = fb;
-
-	info->fbops = &astfb_ops;
-
-	info->apertures->ranges[0].base = pci_resource_start(dev->pdev, 0);
-	info->apertures->ranges[0].size = pci_resource_len(dev->pdev, 0);
-
-	drm_fb_helper_fill_info(info, &afbdev->helper, sizes);
-
-	info->screen_base = sysram;
-	info->screen_size = size;
-
-	info->pixmap.flags = FB_PIXMAP_SYSTEM;
-
-	DRM_DEBUG_KMS("allocated %dx%d\n",
-		      fb->width, fb->height);
-
-	return 0;
-
-out:
-	vfree(sysram);
-	return ret;
-}
-
-static const struct drm_fb_helper_funcs ast_fb_helper_funcs = {
-	.fb_probe = astfb_create,
-};
-
-static void ast_fbdev_destroy(struct drm_device *dev,
-			      struct ast_fbdev *afbdev)
-{
-	drm_helper_force_disable_all(dev);
-	drm_fb_helper_unregister_fbi(&afbdev->helper);
-
-	drm_fb_helper_fini(&afbdev->helper);
-	drm_framebuffer_put(afbdev->helper.fb);
-
-	vfree(afbdev->sysram);
-}
-
-int ast_fbdev_init(struct drm_device *dev)
-{
-	struct ast_private *ast = dev->dev_private;
-	struct ast_fbdev *afbdev;
-	int ret;
-
-	afbdev = kzalloc(sizeof(struct ast_fbdev), GFP_KERNEL);
-	if (!afbdev)
-		return -ENOMEM;
-
-	ast->fbdev = afbdev;
-	spin_lock_init(&afbdev->dirty_lock);
-
-	drm_fb_helper_prepare(dev, &afbdev->helper, &ast_fb_helper_funcs);
-
-	ret = drm_fb_helper_init(dev, &afbdev->helper, 1);
-	if (ret)
-		goto free;
-
-	ret = drm_fb_helper_single_add_all_connectors(&afbdev->helper);
-	if (ret)
-		goto fini;
-
-	/* disable all the possible outputs/crtcs before entering KMS mode */
-	drm_helper_disable_unused_functions(dev);
-
-	ret = drm_fb_helper_initial_config(&afbdev->helper, 32);
-	if (ret)
-		goto fini;
-
-	return 0;
-
-fini:
-	drm_fb_helper_fini(&afbdev->helper);
-free:
-	kfree(afbdev);
-	return ret;
-}
-
-void ast_fbdev_fini(struct drm_device *dev)
-{
-	struct ast_private *ast = dev->dev_private;
-
-	if (!ast->fbdev)
-		return;
-
-	ast_fbdev_destroy(dev, ast->fbdev);
-	kfree(ast->fbdev);
-	ast->fbdev = NULL;
-}
-
-void ast_fbdev_set_suspend(struct drm_device *dev, int state)
-{
-	struct ast_private *ast = dev->dev_private;
-
-	if (!ast->fbdev)
-		return;
-
-	drm_fb_helper_set_suspend(&ast->fbdev->helper, state);
-}
-
-void ast_fbdev_set_base(struct ast_private *ast, unsigned long gpu_addr)
-{
-	ast->fbdev->helper.fbdev->fix.smem_start =
-		ast->fbdev->helper.fbdev->apertures->ranges[0].base + gpu_addr;
-	ast->fbdev->helper.fbdev->fix.smem_len = ast->vram_size - gpu_addr;
-}
diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index 1bd61696e509..78e8e20ff577 100644
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -383,8 +383,33 @@ static int ast_get_dram_info(struct drm_device *dev)
 	return 0;
 }
 
+static int ast_framebuffer_dirtyfb(struct drm_framebuffer *fb,
+				   struct drm_file *file_priv,
+				   unsigned int flags,
+				   unsigned int color,
+				   struct drm_clip_rect *clips,
+				   unsigned int num_clips)
+{
+	/* empty placeholder function to enable fbcon shadow buffer */
+	return 0;
+}
+
+static const struct drm_framebuffer_funcs ast_framebuffer_funcs = {
+	.destroy	= drm_gem_fb_destroy,
+	.create_handle	= drm_gem_fb_create_handle,
+	.dirty		= ast_framebuffer_dirtyfb,
+};
+
+static struct drm_framebuffer *
+ast_mode_config_fb_create(struct drm_device *dev, struct drm_file *file,
+			  const struct drm_mode_fb_cmd2 *mode_cmd)
+{
+	return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
+					    &ast_framebuffer_funcs);
+}
+
 static const struct drm_mode_config_funcs ast_mode_funcs = {
-	.fb_create = drm_gem_fb_create
+	.fb_create = ast_mode_config_fb_create
 };
 
 static u32 ast_get_vram_info(struct drm_device *dev)
@@ -502,7 +527,7 @@ int ast_driver_load(struct drm_device *dev, unsigned long flags)
 	if (ret)
 		goto out_free;
 
-	ret = ast_fbdev_init(dev);
+	ret = drm_fbdev_generic_setup(dev, 32);
 	if (ret)
 		goto out_free;
 
@@ -520,7 +545,6 @@ void ast_driver_unload(struct drm_device *dev)
 	ast_release_firmware(dev);
 	kfree(ast->dp501_fw_addr);
 	ast_mode_fini(dev);
-	ast_fbdev_fini(dev);
 	drm_mode_config_cleanup(dev);
 
 	ast_mm_fini(ast);
diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index c48249df758e..3c0716891b29 100644
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -525,18 +525,12 @@ static int ast_crtc_do_set_base(struct drm_crtc *crtc,
 				struct drm_framebuffer *fb,
 				int x, int y, int atomic)
 {
-	struct ast_private *ast = crtc->dev->dev_private;
 	struct drm_gem_vram_object *gbo;
 	int ret;
 	s64 gpu_addr;
-	void *base;
 
 	if (!atomic && fb) {
 		gbo = drm_gem_vram_of_gem(fb->obj[0]);
-
-		/* unmap if console */
-		if (ast->fbdev->helper.fb == fb)
-			drm_gem_vram_kunmap(gbo);
 		drm_gem_vram_unpin(gbo);
 	}
 
@@ -551,17 +545,6 @@ static int ast_crtc_do_set_base(struct drm_crtc *crtc,
 		goto err_drm_gem_vram_unpin;
 	}
 
-	if (ast->fbdev->helper.fb == crtc->primary->fb) {
-		/* if pushing console in kmap it */
-		base = drm_gem_vram_kmap(gbo, true, NULL);
-		if (IS_ERR(base)) {
-			ret = PTR_ERR(base);
-			DRM_ERROR("failed to kmap fbcon\n");
-		} else {
-			ast_fbdev_set_base(ast, gpu_addr);
-		}
-	}
-
 	ast_set_offset_reg(crtc);
 	ast_set_start_address_crt1(crtc, (u32)gpu_addr);
 
@@ -618,14 +601,10 @@ static void ast_crtc_disable(struct drm_crtc *crtc)
 	DRM_DEBUG_KMS("\n");
 	ast_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
 	if (crtc->primary->fb) {
-		struct ast_private *ast = crtc->dev->dev_private;
 		struct drm_framebuffer *fb = crtc->primary->fb;
 		struct drm_gem_vram_object *gbo =
 			drm_gem_vram_of_gem(fb->obj[0]);
 
-		/* unmap if console */
-		if (ast->fbdev->helper.fb == fb)
-			drm_gem_vram_kunmap(gbo);
 		drm_gem_vram_unpin(gbo);
 	}
 	crtc->primary->fb = NULL;
-- 
2.21.0

[PATCH 3/5] drm/ast: Replace struct ast_fbdev with generic framebuffer emulation

[Thomas Zimmermann]

This patch replaces ast's framebuffer console with DRM's generic
implememtation. All respective code is being removed from the driver.

The console is set up with a shadow buffer. The actual buffer object is
not permanently pinned in video ram, but just another buffer object that
the driver moves in and out of vram as necessary. The driver's function
ast_crtc_do_set_base() used to contain special handling for the framebuffer
console. With the new generic framebuffer, the driver does not need this
code an longer.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/ast/Makefile   |   2 +-
 drivers/gpu/drm/ast/ast_drv.c  |  22 ++-
 drivers/gpu/drm/ast/ast_drv.h  |  17 --
 drivers/gpu/drm/ast/ast_fb.c   | 341 ---------------------------------
 drivers/gpu/drm/ast/ast_main.c |  30 ++-
 drivers/gpu/drm/ast/ast_mode.c |  21 --
 6 files changed, 41 insertions(+), 392 deletions(-)
 delete mode 100644 drivers/gpu/drm/ast/ast_fb.c

diff --git a/drivers/gpu/drm/ast/Makefile b/drivers/gpu/drm/ast/Makefile
index b086dae17013..561f7c4199e4 100644
--- a/drivers/gpu/drm/ast/Makefile
+++ b/drivers/gpu/drm/ast/Makefile
@@ -3,6 +3,6 @@
 # Makefile for the drm device driver.  This driver provides support for the
 # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
 
-ast-y := ast_drv.o ast_main.o ast_mode.o ast_fb.o ast_ttm.o ast_post.o ast_dp501.o
+ast-y := ast_drv.o ast_main.o ast_mode.o ast_ttm.o ast_post.o ast_dp501.o
 
 obj-$(CONFIG_DRM_AST) := ast.o
diff --git a/drivers/gpu/drm/ast/ast_drv.c b/drivers/gpu/drm/ast/ast_drv.c
index 3811997e78c4..75f55ac1a218 100644
--- a/drivers/gpu/drm/ast/ast_drv.c
+++ b/drivers/gpu/drm/ast/ast_drv.c
@@ -103,25 +103,29 @@ static int ast_drm_freeze(struct drm_device *dev)
 
 	pci_save_state(dev->pdev);
 
-	console_lock();
-	ast_fbdev_set_suspend(dev, 1);
-	console_unlock();
+	if (dev->fb_helper) {
+		console_lock();
+		drm_fb_helper_set_suspend(dev->fb_helper, 1);
+		console_unlock();
+	}
+
 	return 0;
 }
 
 static int ast_drm_thaw(struct drm_device *dev)
 {
-	int error = 0;
-
 	ast_post_gpu(dev);
 
 	drm_mode_config_reset(dev);
 	drm_helper_resume_force_mode(dev);
 
-	console_lock();
-	ast_fbdev_set_suspend(dev, 0);
-	console_unlock();
-	return error;
+	if (dev->fb_helper) {
+		console_lock();
+		drm_fb_helper_set_suspend(dev->fb_helper, 0);
+		console_unlock();
+	}
+
+	return 0;
 }
 
 static int ast_drm_resume(struct drm_device *dev)
diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index ca794a3fcf8f..907d7480b7ba 100644
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -81,8 +81,6 @@ enum ast_tx_chip {
 #define AST_DRAM_4Gx16   7
 #define AST_DRAM_8Gx16   8
 
-struct ast_fbdev;
-
 struct ast_private {
 	struct drm_device *dev;
 
@@ -96,8 +94,6 @@ struct ast_private {
 	uint32_t mclk;
 	uint32_t vram_size;
 
-	struct ast_fbdev *fbdev;
-
 	int fb_mtrr;
 
 	struct drm_gem_object *cursor_cache;
@@ -239,14 +235,6 @@ struct ast_encoder {
 	struct drm_encoder base;
 };
 
-struct ast_fbdev {
-	struct drm_fb_helper helper; /* must be first */
-	void *sysram;
-	int size;
-	int x1, y1, x2, y2; /* dirty rect */
-	spinlock_t dirty_lock;
-};
-
 #define to_ast_crtc(x) container_of(x, struct ast_crtc, base)
 #define to_ast_connector(x) container_of(x, struct ast_connector, base)
 #define to_ast_encoder(x) container_of(x, struct ast_encoder, base)
@@ -289,11 +277,6 @@ struct ast_vbios_mode_info {
 extern int ast_mode_init(struct drm_device *dev);
 extern void ast_mode_fini(struct drm_device *dev);
 
-int ast_fbdev_init(struct drm_device *dev);
-void ast_fbdev_fini(struct drm_device *dev);
-void ast_fbdev_set_suspend(struct drm_device *dev, int state);
-void ast_fbdev_set_base(struct ast_private *ast, unsigned long gpu_addr);
-
 #define AST_MM_ALIGN_SHIFT 4
 #define AST_MM_ALIGN_MASK ((1 << AST_MM_ALIGN_SHIFT) - 1)
 
diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c
deleted file mode 100644
index a849e58b40bc..000000000000
--- a/drivers/gpu/drm/ast/ast_fb.c
+++ /dev/null
@@ -1,341 +0,0 @@
-/*
- * Copyright 2012 Red Hat Inc.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the
- * "Software"), to deal in the Software without restriction, including
- * without limitation the rights to use, copy, modify, merge, publish,
- * distribute, sub license, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to
- * the following conditions:
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
- * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
- * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
- * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
- * USE OR OTHER DEALINGS IN THE SOFTWARE.
- *
- * The above copyright notice and this permission notice (including the
- * next paragraph) shall be included in all copies or substantial portions
- * of the Software.
- *
- */
-/*
- * Authors: Dave Airlie <airlied@redhat.com>
- */
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/mm.h>
-#include <linux/tty.h>
-#include <linux/sysrq.h>
-#include <linux/delay.h>
-#include <linux/init.h>
-
-
-#include <drm/drmP.h>
-#include <drm/drm_crtc.h>
-#include <drm/drm_crtc_helper.h>
-#include <drm/drm_fb_helper.h>
-#include <drm/drm_gem_framebuffer_helper.h>
-#include <drm/drm_util.h>
-
-#include "ast_drv.h"
-
-static void ast_dirty_update(struct ast_fbdev *afbdev,
-			     int x, int y, int width, int height)
-{
-	int i;
-	struct drm_gem_vram_object *gbo;
-	int src_offset, dst_offset;
-	int ret;
-	u8 *dst;
-	bool unmap = false;
-	bool store_for_later = false;
-	int x2, y2;
-	unsigned long flags;
-	struct drm_framebuffer *fb = afbdev->helper.fb;
-	int bpp = fb->format->cpp[0];
-
-	gbo = drm_gem_vram_of_gem(fb->obj[0]);
-
-	if (drm_can_sleep()) {
-		/* We pin the BO so it won't be moved during the
-		 * update. The actual location, video RAM or system
-		 * memory, is not important.
-		 */
-		ret = drm_gem_vram_pin(gbo, 0);
-		if (ret) {
-			if (ret != -EBUSY)
-				return;
-			store_for_later = true;
-		}
-	} else {
-		store_for_later = true;
-	}
-
-	x2 = x + width - 1;
-	y2 = y + height - 1;
-	spin_lock_irqsave(&afbdev->dirty_lock, flags);
-
-	if (afbdev->y1 < y)
-		y = afbdev->y1;
-	if (afbdev->y2 > y2)
-		y2 = afbdev->y2;
-	if (afbdev->x1 < x)
-		x = afbdev->x1;
-	if (afbdev->x2 > x2)
-		x2 = afbdev->x2;
-
-	if (store_for_later) {
-		afbdev->x1 = x;
-		afbdev->x2 = x2;
-		afbdev->y1 = y;
-		afbdev->y2 = y2;
-		spin_unlock_irqrestore(&afbdev->dirty_lock, flags);
-		return;
-	}
-
-	afbdev->x1 = afbdev->y1 = INT_MAX;
-	afbdev->x2 = afbdev->y2 = 0;
-	spin_unlock_irqrestore(&afbdev->dirty_lock, flags);
-
-	dst = drm_gem_vram_kmap(gbo, false, NULL);
-	if (IS_ERR(dst)) {
-		DRM_ERROR("failed to kmap fb updates\n");
-		goto out;
-	} else if (!dst) {
-		dst = drm_gem_vram_kmap(gbo, true, NULL);
-		if (IS_ERR(dst)) {
-			DRM_ERROR("failed to kmap fb updates\n");
-			goto out;
-		}
-		unmap = true;
-	}
-
-	for (i = y; i <= y2; i++) {
-		/* assume equal stride for now */
-		src_offset = dst_offset = i * fb->pitches[0] + (x * bpp);
-		memcpy_toio(dst + dst_offset, afbdev->sysram + src_offset,
-			    (x2 - x + 1) * bpp);
-	}
-
-	if (unmap)
-		drm_gem_vram_kunmap(gbo);
-
-out:
-	drm_gem_vram_unpin(gbo);
-}
-
-static void ast_fillrect(struct fb_info *info,
-			 const struct fb_fillrect *rect)
-{
-	struct ast_fbdev *afbdev = info->par;
-	drm_fb_helper_sys_fillrect(info, rect);
-	ast_dirty_update(afbdev, rect->dx, rect->dy, rect->width,
-			 rect->height);
-}
-
-static void ast_copyarea(struct fb_info *info,
-			 const struct fb_copyarea *area)
-{
-	struct ast_fbdev *afbdev = info->par;
-	drm_fb_helper_sys_copyarea(info, area);
-	ast_dirty_update(afbdev, area->dx, area->dy, area->width,
-			 area->height);
-}
-
-static void ast_imageblit(struct fb_info *info,
-			  const struct fb_image *image)
-{
-	struct ast_fbdev *afbdev = info->par;
-	drm_fb_helper_sys_imageblit(info, image);
-	ast_dirty_update(afbdev, image->dx, image->dy, image->width,
-			 image->height);
-}
-
-static struct fb_ops astfb_ops = {
-	.owner = THIS_MODULE,
-	.fb_check_var = drm_fb_helper_check_var,
-	.fb_set_par = drm_fb_helper_set_par,
-	.fb_fillrect = ast_fillrect,
-	.fb_copyarea = ast_copyarea,
-	.fb_imageblit = ast_imageblit,
-	.fb_pan_display = drm_fb_helper_pan_display,
-	.fb_blank = drm_fb_helper_blank,
-	.fb_setcmap = drm_fb_helper_setcmap,
-};
-
-static int astfb_create_object(struct ast_fbdev *afbdev,
-			       const struct drm_mode_fb_cmd2 *mode_cmd,
-			       struct drm_gem_object **gobj_p)
-{
-	struct drm_device *dev = afbdev->helper.dev;
-	u32 size;
-	struct drm_gem_object *gobj;
-	int ret = 0;
-
-	size = mode_cmd->pitches[0] * mode_cmd->height;
-	ret = ast_gem_create(dev, size, true, &gobj);
-	if (ret)
-		return ret;
-
-	*gobj_p = gobj;
-	return ret;
-}
-
-static int astfb_create(struct drm_fb_helper *helper,
-			struct drm_fb_helper_surface_size *sizes)
-{
-	struct ast_fbdev *afbdev =
-		container_of(helper, struct ast_fbdev, helper);
-	struct drm_device *dev = afbdev->helper.dev;
-	struct drm_mode_fb_cmd2 mode_cmd;
-	struct drm_framebuffer *fb;
-	struct fb_info *info;
-	int size, ret;
-	void *sysram;
-	struct drm_gem_object *gobj = NULL;
-	mode_cmd.width = sizes->surface_width;
-	mode_cmd.height = sizes->surface_height;
-	mode_cmd.pitches[0] = mode_cmd.width * ((sizes->surface_bpp + 7)/8);
-
-	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
-							  sizes->surface_depth);
-
-	size = mode_cmd.pitches[0] * mode_cmd.height;
-
-	ret = astfb_create_object(afbdev, &mode_cmd, &gobj);
-	if (ret) {
-		DRM_ERROR("failed to create fbcon backing object %d\n", ret);
-		return ret;
-	}
-
-	sysram = vmalloc(size);
-	if (!sysram)
-		return -ENOMEM;
-
-	info = drm_fb_helper_alloc_fbi(helper);
-	if (IS_ERR(info)) {
-		ret = PTR_ERR(info);
-		goto out;
-	}
-	fb = drm_gem_fbdev_fb_create(dev, sizes, 0, gobj, NULL);
-	if (IS_ERR(fb)) {
-		ret = PTR_ERR(fb);
-		goto out;
-	}
-
-	afbdev->sysram = sysram;
-	afbdev->size = size;
-
-	afbdev->helper.fb = fb;
-
-	info->fbops = &astfb_ops;
-
-	info->apertures->ranges[0].base = pci_resource_start(dev->pdev, 0);
-	info->apertures->ranges[0].size = pci_resource_len(dev->pdev, 0);
-
-	drm_fb_helper_fill_info(info, &afbdev->helper, sizes);
-
-	info->screen_base = sysram;
-	info->screen_size = size;
-
-	info->pixmap.flags = FB_PIXMAP_SYSTEM;
-
-	DRM_DEBUG_KMS("allocated %dx%d\n",
-		      fb->width, fb->height);
-
-	return 0;
-
-out:
-	vfree(sysram);
-	return ret;
-}
-
-static const struct drm_fb_helper_funcs ast_fb_helper_funcs = {
-	.fb_probe = astfb_create,
-};
-
-static void ast_fbdev_destroy(struct drm_device *dev,
-			      struct ast_fbdev *afbdev)
-{
-	drm_helper_force_disable_all(dev);
-	drm_fb_helper_unregister_fbi(&afbdev->helper);
-
-	drm_fb_helper_fini(&afbdev->helper);
-	drm_framebuffer_put(afbdev->helper.fb);
-
-	vfree(afbdev->sysram);
-}
-
-int ast_fbdev_init(struct drm_device *dev)
-{
-	struct ast_private *ast = dev->dev_private;
-	struct ast_fbdev *afbdev;
-	int ret;
-
-	afbdev = kzalloc(sizeof(struct ast_fbdev), GFP_KERNEL);
-	if (!afbdev)
-		return -ENOMEM;
-
-	ast->fbdev = afbdev;
-	spin_lock_init(&afbdev->dirty_lock);
-
-	drm_fb_helper_prepare(dev, &afbdev->helper, &ast_fb_helper_funcs);
-
-	ret = drm_fb_helper_init(dev, &afbdev->helper, 1);
-	if (ret)
-		goto free;
-
-	ret = drm_fb_helper_single_add_all_connectors(&afbdev->helper);
-	if (ret)
-		goto fini;
-
-	/* disable all the possible outputs/crtcs before entering KMS mode */
-	drm_helper_disable_unused_functions(dev);
-
-	ret = drm_fb_helper_initial_config(&afbdev->helper, 32);
-	if (ret)
-		goto fini;
-
-	return 0;
-
-fini:
-	drm_fb_helper_fini(&afbdev->helper);
-free:
-	kfree(afbdev);
-	return ret;
-}
-
-void ast_fbdev_fini(struct drm_device *dev)
-{
-	struct ast_private *ast = dev->dev_private;
-
-	if (!ast->fbdev)
-		return;
-
-	ast_fbdev_destroy(dev, ast->fbdev);
-	kfree(ast->fbdev);
-	ast->fbdev = NULL;
-}
-
-void ast_fbdev_set_suspend(struct drm_device *dev, int state)
-{
-	struct ast_private *ast = dev->dev_private;
-
-	if (!ast->fbdev)
-		return;
-
-	drm_fb_helper_set_suspend(&ast->fbdev->helper, state);
-}
-
-void ast_fbdev_set_base(struct ast_private *ast, unsigned long gpu_addr)
-{
-	ast->fbdev->helper.fbdev->fix.smem_start =
-		ast->fbdev->helper.fbdev->apertures->ranges[0].base + gpu_addr;
-	ast->fbdev->helper.fbdev->fix.smem_len = ast->vram_size - gpu_addr;
-}
diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index 1bd61696e509..78e8e20ff577 100644
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -383,8 +383,33 @@ static int ast_get_dram_info(struct drm_device *dev)
 	return 0;
 }
 
+static int ast_framebuffer_dirtyfb(struct drm_framebuffer *fb,
+				   struct drm_file *file_priv,
+				   unsigned int flags,
+				   unsigned int color,
+				   struct drm_clip_rect *clips,
+				   unsigned int num_clips)
+{
+	/* empty placeholder function to enable fbcon shadow buffer */
+	return 0;
+}
+
+static const struct drm_framebuffer_funcs ast_framebuffer_funcs = {
+	.destroy	= drm_gem_fb_destroy,
+	.create_handle	= drm_gem_fb_create_handle,
+	.dirty		= ast_framebuffer_dirtyfb,
+};
+
+static struct drm_framebuffer *
+ast_mode_config_fb_create(struct drm_device *dev, struct drm_file *file,
+			  const struct drm_mode_fb_cmd2 *mode_cmd)
+{
+	return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
+					    &ast_framebuffer_funcs);
+}
+
 static const struct drm_mode_config_funcs ast_mode_funcs = {
-	.fb_create = drm_gem_fb_create
+	.fb_create = ast_mode_config_fb_create
 };
 
 static u32 ast_get_vram_info(struct drm_device *dev)
@@ -502,7 +527,7 @@ int ast_driver_load(struct drm_device *dev, unsigned long flags)
 	if (ret)
 		goto out_free;
 
-	ret = ast_fbdev_init(dev);
+	ret = drm_fbdev_generic_setup(dev, 32);
 	if (ret)
 		goto out_free;
 
@@ -520,7 +545,6 @@ void ast_driver_unload(struct drm_device *dev)
 	ast_release_firmware(dev);
 	kfree(ast->dp501_fw_addr);
 	ast_mode_fini(dev);
-	ast_fbdev_fini(dev);
 	drm_mode_config_cleanup(dev);
 
 	ast_mm_fini(ast);
diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index c48249df758e..3c0716891b29 100644
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -525,18 +525,12 @@ static int ast_crtc_do_set_base(struct drm_crtc *crtc,
 				struct drm_framebuffer *fb,
 				int x, int y, int atomic)
 {
-	struct ast_private *ast = crtc->dev->dev_private;
 	struct drm_gem_vram_object *gbo;
 	int ret;
 	s64 gpu_addr;
-	void *base;
 
 	if (!atomic && fb) {
 		gbo = drm_gem_vram_of_gem(fb->obj[0]);
-
-		/* unmap if console */
-		if (ast->fbdev->helper.fb == fb)
-			drm_gem_vram_kunmap(gbo);
 		drm_gem_vram_unpin(gbo);
 	}
 
@@ -551,17 +545,6 @@ static int ast_crtc_do_set_base(struct drm_crtc *crtc,
 		goto err_drm_gem_vram_unpin;
 	}
 
-	if (ast->fbdev->helper.fb == crtc->primary->fb) {
-		/* if pushing console in kmap it */
-		base = drm_gem_vram_kmap(gbo, true, NULL);
-		if (IS_ERR(base)) {
-			ret = PTR_ERR(base);
-			DRM_ERROR("failed to kmap fbcon\n");
-		} else {
-			ast_fbdev_set_base(ast, gpu_addr);
-		}
-	}
-
 	ast_set_offset_reg(crtc);
 	ast_set_start_address_crt1(crtc, (u32)gpu_addr);
 
@@ -618,14 +601,10 @@ static void ast_crtc_disable(struct drm_crtc *crtc)
 	DRM_DEBUG_KMS("\n");
 	ast_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
 	if (crtc->primary->fb) {
-		struct ast_private *ast = crtc->dev->dev_private;
 		struct drm_framebuffer *fb = crtc->primary->fb;
 		struct drm_gem_vram_object *gbo =
 			drm_gem_vram_of_gem(fb->obj[0]);
 
-		/* unmap if console */
-		if (ast->fbdev->helper.fb == fb)
-			drm_gem_vram_kunmap(gbo);
 		drm_gem_vram_unpin(gbo);
 	}
 	crtc->primary->fb = NULL;
-- 
2.21.0

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[PATCH 4/5] drm/bochs: Use shadow buffer for bochs framebuffer console

[Thomas Zimmermann]

The bochs driver (and virtual hardware) requires buffer objects to
reside in video ram to display them to the screen. So it can not
display the framebuffer console because the respective buffer object
is permanently pinned in system memory.

Using a shadow buffer for the console solves this problem. The console
emulation will pin the buffer object only during updates from the shadow
buffer. Otherwise, the bochs driver can freely relocated the buffer
between system memory and video ram.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/bochs/bochs_kms.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bochs/bochs_kms.c b/drivers/gpu/drm/bochs/bochs_kms.c
index bc19dbd531ef..47fab4852483 100644
--- a/drivers/gpu/drm/bochs/bochs_kms.c
+++ b/drivers/gpu/drm/bochs/bochs_kms.c
@@ -172,7 +172,7 @@ bochs_gem_fb_create(struct drm_device *dev, struct drm_file *file,
 	    mode_cmd->pixel_format != DRM_FORMAT_BGRX8888)
 		return ERR_PTR(-EINVAL);
 
-	return drm_gem_fb_create(dev, file, mode_cmd);
+	return drm_gem_fb_create_with_dirty(dev, file, mode_cmd);
 }
 
 const struct drm_mode_config_funcs bochs_mode_funcs = {
-- 
2.21.0

[PATCH 4/5] drm/bochs: Use shadow buffer for bochs framebuffer console

[Thomas Zimmermann]

The bochs driver (and virtual hardware) requires buffer objects to
reside in video ram to display them to the screen. So it can not
display the framebuffer console because the respective buffer object
is permanently pinned in system memory.

Using a shadow buffer for the console solves this problem. The console
emulation will pin the buffer object only during updates from the shadow
buffer. Otherwise, the bochs driver can freely relocated the buffer
between system memory and video ram.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/bochs/bochs_kms.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bochs/bochs_kms.c b/drivers/gpu/drm/bochs/bochs_kms.c
index bc19dbd531ef..47fab4852483 100644
--- a/drivers/gpu/drm/bochs/bochs_kms.c
+++ b/drivers/gpu/drm/bochs/bochs_kms.c
@@ -172,7 +172,7 @@ bochs_gem_fb_create(struct drm_device *dev, struct drm_file *file,
 	    mode_cmd->pixel_format != DRM_FORMAT_BGRX8888)
 		return ERR_PTR(-EINVAL);
 
-	return drm_gem_fb_create(dev, file, mode_cmd);
+	return drm_gem_fb_create_with_dirty(dev, file, mode_cmd);
 }
 
 const struct drm_mode_config_funcs bochs_mode_funcs = {
-- 
2.21.0

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[PATCH 5/5] drm/mgag200: Replace struct mga_fbdev with generic framebuffer emulation

[Thomas Zimmermann]

This patch replaces mgag200's framebuffer console with DRM's generic
implememtation. All respective code is being removed from the driver.

The console is set up with a shadow buffer. The actual buffer object is
not permanently pinned in video ram, but just another buffer object that
the driver moves in and out of vram as necessary. The driver's function
mga_crtc_do_set_base() used to contain special handling for the framebuffer
console. With the new generic framebuffer, the driver does not need this
code an longer.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/mgag200/Makefile       |   2 +-
 drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
 drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 -------------------------
 drivers/gpu/drm/mgag200/mgag200_main.c |  61 ++---
 drivers/gpu/drm/mgag200/mgag200_mode.c |  27 ---
 5 files changed, 35 insertions(+), 383 deletions(-)
 delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c

diff --git a/drivers/gpu/drm/mgag200/Makefile b/drivers/gpu/drm/mgag200/Makefile
index 98d204408bd0..04b281bcf655 100644
--- a/drivers/gpu/drm/mgag200/Makefile
+++ b/drivers/gpu/drm/mgag200/Makefile
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
 mgag200-y   := mgag200_main.o mgag200_mode.o mgag200_cursor.o \
-	mgag200_drv.o mgag200_fb.o mgag200_i2c.o mgag200_ttm.o
+	mgag200_drv.o mgag200_i2c.o mgag200_ttm.o
 
 obj-$(CONFIG_DRM_MGAG200) += mgag200.o
diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.h b/drivers/gpu/drm/mgag200/mgag200_drv.h
index 3ab27f1053c1..1c93f8dc08c7 100644
--- a/drivers/gpu/drm/mgag200/mgag200_drv.h
+++ b/drivers/gpu/drm/mgag200/mgag200_drv.h
@@ -99,14 +99,6 @@
 #define to_mga_encoder(x) container_of(x, struct mga_encoder, base)
 #define to_mga_connector(x) container_of(x, struct mga_connector, base)
 
-struct mga_fbdev {
-	struct drm_fb_helper helper; /* must be first */
-	void *sysram;
-	int size;
-	int x1, y1, x2, y2; /* dirty rect */
-	spinlock_t dirty_lock;
-};
-
 struct mga_crtc {
 	struct drm_crtc base;
 	u8 lut_r[256], lut_g[256], lut_b[256];
@@ -180,7 +172,6 @@ struct mga_device {
 	struct mga_mc			mc;
 	struct mga_mode_info		mode_info;
 
-	struct mga_fbdev *mfbdev;
 	struct mga_cursor cursor;
 
 	bool				suspended;
@@ -201,19 +192,9 @@ struct mga_device {
 int mgag200_modeset_init(struct mga_device *mdev);
 void mgag200_modeset_fini(struct mga_device *mdev);
 
-				/* mgag200_fb.c */
-int mgag200_fbdev_init(struct mga_device *mdev);
-void mgag200_fbdev_fini(struct mga_device *mdev);
-
 				/* mgag200_main.c */
 int mgag200_driver_load(struct drm_device *dev, unsigned long flags);
 void mgag200_driver_unload(struct drm_device *dev);
-int mgag200_gem_create(struct drm_device *dev,
-		   u32 size, bool iskernel,
-		       struct drm_gem_object **obj);
-int mgag200_dumb_create(struct drm_file *file,
-			struct drm_device *dev,
-			struct drm_mode_create_dumb *args);
 
 				/* mgag200_i2c.c */
 struct mga_i2c_chan *mgag200_i2c_create(struct drm_device *dev);
diff --git a/drivers/gpu/drm/mgag200/mgag200_fb.c b/drivers/gpu/drm/mgag200/mgag200_fb.c
deleted file mode 100644
index c77cf1b34c98..000000000000
--- a/drivers/gpu/drm/mgag200/mgag200_fb.c
+++ /dev/null
@@ -1,309 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright 2010 Matt Turner.
- * Copyright 2012 Red Hat
- *
- * Authors: Matthew Garrett
- *          Matt Turner
- *          Dave Airlie
- */
-
-#include <linux/module.h>
-#include <linux/vmalloc.h>
-
-#include <drm/drm_crtc_helper.h>
-#include <drm/drm_fb_helper.h>
-#include <drm/drm_fourcc.h>
-#include <drm/drm_gem_framebuffer_helper.h>
-#include <drm/drm_util.h>
-
-#include "mgag200_drv.h"
-
-static void mga_dirty_update(struct mga_fbdev *mfbdev,
-			     int x, int y, int width, int height)
-{
-	int i;
-	struct drm_gem_vram_object *gbo;
-	int src_offset, dst_offset;
-	int ret;
-	u8 *dst;
-	bool unmap = false;
-	bool store_for_later = false;
-	int x2, y2;
-	unsigned long flags;
-	struct drm_framebuffer *fb = mfbdev->helper.fb;
-	int bpp = fb->format->cpp[0];
-
-	gbo = drm_gem_vram_of_gem(fb->obj[0]);
-
-	if (drm_can_sleep()) {
-		/* We pin the BO so it won't be moved during the
-		 * update. The actual location, video RAM or system
-		 * memory, is not important.
-		 */
-		ret = drm_gem_vram_pin(gbo, 0);
-		if (ret) {
-			if (ret != -EBUSY)
-				return;
-			store_for_later = true;
-		}
-	} else {
-		store_for_later = true;
-	}
-
-	x2 = x + width - 1;
-	y2 = y + height - 1;
-	spin_lock_irqsave(&mfbdev->dirty_lock, flags);
-
-	if (mfbdev->y1 < y)
-		y = mfbdev->y1;
-	if (mfbdev->y2 > y2)
-		y2 = mfbdev->y2;
-	if (mfbdev->x1 < x)
-		x = mfbdev->x1;
-	if (mfbdev->x2 > x2)
-		x2 = mfbdev->x2;
-
-	if (store_for_later) {
-		mfbdev->x1 = x;
-		mfbdev->x2 = x2;
-		mfbdev->y1 = y;
-		mfbdev->y2 = y2;
-		spin_unlock_irqrestore(&mfbdev->dirty_lock, flags);
-		return;
-	}
-
-	mfbdev->x1 = mfbdev->y1 = INT_MAX;
-	mfbdev->x2 = mfbdev->y2 = 0;
-	spin_unlock_irqrestore(&mfbdev->dirty_lock, flags);
-
-	dst = drm_gem_vram_kmap(gbo, false, NULL);
-	if (IS_ERR(dst)) {
-		DRM_ERROR("failed to kmap fb updates\n");
-		goto out;
-	} else if (!dst) {
-		dst = drm_gem_vram_kmap(gbo, true, NULL);
-		if (IS_ERR(dst)) {
-			DRM_ERROR("failed to kmap fb updates\n");
-			goto out;
-		}
-		unmap = true;
-	}
-
-	for (i = y; i <= y2; i++) {
-		/* assume equal stride for now */
-		src_offset = dst_offset = i * fb->pitches[0] + (x * bpp);
-		memcpy_toio(dst + dst_offset, mfbdev->sysram + src_offset,
-			    (x2 - x + 1) * bpp);
-	}
-
-	if (unmap)
-		drm_gem_vram_kunmap(gbo);
-
-out:
-	drm_gem_vram_unpin(gbo);
-}
-
-static void mga_fillrect(struct fb_info *info,
-			 const struct fb_fillrect *rect)
-{
-	struct mga_fbdev *mfbdev = info->par;
-	drm_fb_helper_sys_fillrect(info, rect);
-	mga_dirty_update(mfbdev, rect->dx, rect->dy, rect->width,
-			 rect->height);
-}
-
-static void mga_copyarea(struct fb_info *info,
-			 const struct fb_copyarea *area)
-{
-	struct mga_fbdev *mfbdev = info->par;
-	drm_fb_helper_sys_copyarea(info, area);
-	mga_dirty_update(mfbdev, area->dx, area->dy, area->width,
-			 area->height);
-}
-
-static void mga_imageblit(struct fb_info *info,
-			  const struct fb_image *image)
-{
-	struct mga_fbdev *mfbdev = info->par;
-	drm_fb_helper_sys_imageblit(info, image);
-	mga_dirty_update(mfbdev, image->dx, image->dy, image->width,
-			 image->height);
-}
-
-
-static struct fb_ops mgag200fb_ops = {
-	.owner = THIS_MODULE,
-	.fb_check_var = drm_fb_helper_check_var,
-	.fb_set_par = drm_fb_helper_set_par,
-	.fb_fillrect = mga_fillrect,
-	.fb_copyarea = mga_copyarea,
-	.fb_imageblit = mga_imageblit,
-	.fb_pan_display = drm_fb_helper_pan_display,
-	.fb_blank = drm_fb_helper_blank,
-	.fb_setcmap = drm_fb_helper_setcmap,
-};
-
-static int mgag200fb_create_object(struct mga_fbdev *afbdev,
-				   const struct drm_mode_fb_cmd2 *mode_cmd,
-				   struct drm_gem_object **gobj_p)
-{
-	struct drm_device *dev = afbdev->helper.dev;
-	u32 size;
-	struct drm_gem_object *gobj;
-	int ret = 0;
-
-	size = mode_cmd->pitches[0] * mode_cmd->height;
-	ret = mgag200_gem_create(dev, size, true, &gobj);
-	if (ret)
-		return ret;
-
-	*gobj_p = gobj;
-	return ret;
-}
-
-static int mgag200fb_create(struct drm_fb_helper *helper,
-			   struct drm_fb_helper_surface_size *sizes)
-{
-	struct mga_fbdev *mfbdev =
-		container_of(helper, struct mga_fbdev, helper);
-	struct drm_device *dev = mfbdev->helper.dev;
-	struct drm_mode_fb_cmd2 mode_cmd;
-	struct mga_device *mdev = dev->dev_private;
-	struct fb_info *info;
-	struct drm_framebuffer *fb;
-	struct drm_gem_object *gobj = NULL;
-	int ret;
-	void *sysram;
-	int size;
-
-	mode_cmd.width = sizes->surface_width;
-	mode_cmd.height = sizes->surface_height;
-	mode_cmd.pitches[0] = mode_cmd.width * ((sizes->surface_bpp + 7) / 8);
-
-	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
-							  sizes->surface_depth);
-	size = mode_cmd.pitches[0] * mode_cmd.height;
-
-	ret = mgag200fb_create_object(mfbdev, &mode_cmd, &gobj);
-	if (ret) {
-		DRM_ERROR("failed to create fbcon backing object %d\n", ret);
-		return ret;
-	}
-
-	sysram = vmalloc(size);
-	if (!sysram) {
-		ret = -ENOMEM;
-		goto err_drm_gem_object_put_unlocked;
-	}
-
-	info = drm_fb_helper_alloc_fbi(helper);
-	if (IS_ERR(info)) {
-		ret = PTR_ERR(info);
-		goto err_vfree;
-	}
-
-	fb = drm_gem_fbdev_fb_create(dev, sizes, 0, gobj, NULL);
-	if (IS_ERR(fb)) {
-		ret = PTR_ERR(fb);
-		goto err_vfree;
-	}
-
-	mfbdev->sysram = sysram;
-	mfbdev->size = size;
-
-	/* setup helper */
-	mfbdev->helper.fb = fb;
-
-	info->fbops = &mgag200fb_ops;
-
-	/* setup aperture base/size for vesafb takeover */
-	info->apertures->ranges[0].base = mdev->dev->mode_config.fb_base;
-	info->apertures->ranges[0].size = mdev->mc.vram_size;
-
-	drm_fb_helper_fill_info(info, &mfbdev->helper, sizes);
-
-	info->screen_base = sysram;
-	info->screen_size = size;
-	info->pixmap.flags = FB_PIXMAP_SYSTEM;
-
-	DRM_DEBUG_KMS("allocated %dx%d\n",
-		      fb->width, fb->height);
-
-	return 0;
-
-err_vfree:
-	vfree(sysram);
-err_drm_gem_object_put_unlocked:
-	drm_gem_object_put_unlocked(gobj);
-	return ret;
-}
-
-static int mga_fbdev_destroy(struct drm_device *dev,
-				struct mga_fbdev *mfbdev)
-{
-	drm_fb_helper_unregister_fbi(&mfbdev->helper);
-	drm_fb_helper_fini(&mfbdev->helper);
-	drm_framebuffer_put(mfbdev->helper.fb);
-
-	vfree(mfbdev->sysram);
-
-	return 0;
-}
-
-static const struct drm_fb_helper_funcs mga_fb_helper_funcs = {
-	.fb_probe = mgag200fb_create,
-};
-
-int mgag200_fbdev_init(struct mga_device *mdev)
-{
-	struct mga_fbdev *mfbdev;
-	int ret;
-	int bpp_sel = 32;
-
-	/* prefer 16bpp on low end gpus with limited VRAM */
-	if (IS_G200_SE(mdev) && mdev->mc.vram_size < (2048*1024))
-		bpp_sel = 16;
-
-	mfbdev = devm_kzalloc(mdev->dev->dev, sizeof(struct mga_fbdev), GFP_KERNEL);
-	if (!mfbdev)
-		return -ENOMEM;
-
-	mdev->mfbdev = mfbdev;
-	spin_lock_init(&mfbdev->dirty_lock);
-
-	drm_fb_helper_prepare(mdev->dev, &mfbdev->helper, &mga_fb_helper_funcs);
-
-	ret = drm_fb_helper_init(mdev->dev, &mfbdev->helper,
-				 MGAG200FB_CONN_LIMIT);
-	if (ret)
-		goto err_fb_helper;
-
-	ret = drm_fb_helper_single_add_all_connectors(&mfbdev->helper);
-	if (ret)
-		goto err_fb_setup;
-
-	/* disable all the possible outputs/crtcs before entering KMS mode */
-	drm_helper_disable_unused_functions(mdev->dev);
-
-	ret = drm_fb_helper_initial_config(&mfbdev->helper, bpp_sel);
-	if (ret)
-		goto err_fb_setup;
-
-	return 0;
-
-err_fb_setup:
-	drm_fb_helper_fini(&mfbdev->helper);
-err_fb_helper:
-	mdev->mfbdev = NULL;
-
-	return ret;
-}
-
-void mgag200_fbdev_fini(struct mga_device *mdev)
-{
-	if (!mdev->mfbdev)
-		return;
-
-	mga_fbdev_destroy(mdev->dev, mdev->mfbdev);
-}
diff --git a/drivers/gpu/drm/mgag200/mgag200_main.c b/drivers/gpu/drm/mgag200/mgag200_main.c
index b10f7265b5c4..6d943a008752 100644
--- a/drivers/gpu/drm/mgag200/mgag200_main.c
+++ b/drivers/gpu/drm/mgag200/mgag200_main.c
@@ -14,8 +14,33 @@
 
 #include "mgag200_drv.h"
 
+static int mga_framebuffer_dirtyfb(struct drm_framebuffer *fb,
+				   struct drm_file *file_priv,
+				   unsigned int flags,
+				   unsigned int color,
+				   struct drm_clip_rect *clips,
+				   unsigned int num_clips)
+{
+	/* empty placeholder function to enable fbcon shadow buffer */
+	return 0;
+}
+
+static const struct drm_framebuffer_funcs mga_framebuffer_funcs = {
+	.destroy	= drm_gem_fb_destroy,
+	.create_handle	= drm_gem_fb_create_handle,
+	.dirty		= mga_framebuffer_dirtyfb,
+};
+
+static struct drm_framebuffer *
+mga_mode_config_funcs_fb_create(struct drm_device *dev, struct drm_file *file,
+				const struct drm_mode_fb_cmd2 *mode_cmd)
+{
+	return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
+					    &mga_framebuffer_funcs);
+}
+
 static const struct drm_mode_config_funcs mga_mode_funcs = {
-	.fb_create = drm_gem_fb_create
+	.fb_create = mga_mode_config_funcs_fb_create
 };
 
 static int mga_probe_vram(struct mga_device *mdev, void __iomem *mem)
@@ -162,7 +187,7 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
 	if (IS_G200_SE(mdev) && mdev->mc.vram_size < (2048*1024))
 		dev->mode_config.preferred_depth = 16;
 	else
-		dev->mode_config.preferred_depth = 24;
+		dev->mode_config.preferred_depth = 32;
 	dev->mode_config.prefer_shadow = 1;
 
 	r = mgag200_modeset_init(mdev);
@@ -186,6 +211,13 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
 	}
 	mdev->cursor.pixels_current = NULL;
 
+	r = drm_fbdev_generic_setup(mdev->dev, 0);
+	if (r) {
+		dev_err(&dev->pdev->dev,
+			"drm_fbdev_generic_setup failed: %d\n", r);
+		goto err_modeset;
+	}
+
 	return 0;
 
 err_modeset:
@@ -204,32 +236,7 @@ void mgag200_driver_unload(struct drm_device *dev)
 	if (mdev == NULL)
 		return;
 	mgag200_modeset_fini(mdev);
-	mgag200_fbdev_fini(mdev);
 	drm_mode_config_cleanup(dev);
 	mgag200_mm_fini(mdev);
 	dev->dev_private = NULL;
 }
-
-int mgag200_gem_create(struct drm_device *dev,
-		   u32 size, bool iskernel,
-		   struct drm_gem_object **obj)
-{
-	struct drm_gem_vram_object *gbo;
-	int ret;
-
-	*obj = NULL;
-
-	size = roundup(size, PAGE_SIZE);
-	if (size == 0)
-		return -EINVAL;
-
-	gbo = drm_gem_vram_create(dev, &dev->vram_mm->bdev, size, 0, false);
-	if (IS_ERR(gbo)) {
-		ret = PTR_ERR(gbo);
-		if (ret != -ERESTARTSYS)
-			DRM_ERROR("failed to allocate GEM object\n");
-		return ret;
-	}
-	*obj = &gbo->gem;
-	return 0;
-}
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index a7cef78d426f..822f2a13748f 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -860,18 +860,12 @@ static int mga_crtc_do_set_base(struct drm_crtc *crtc,
 				struct drm_framebuffer *fb,
 				int x, int y, int atomic)
 {
-	struct mga_device *mdev = crtc->dev->dev_private;
 	struct drm_gem_vram_object *gbo;
 	int ret;
 	s64 gpu_addr;
-	void *base;
 
 	if (!atomic && fb) {
 		gbo = drm_gem_vram_of_gem(fb->obj[0]);
-
-		/* unmap if console */
-		if (mdev->mfbdev->helper.fb == fb)
-			drm_gem_vram_kunmap(gbo);
 		drm_gem_vram_unpin(gbo);
 	}
 
@@ -886,15 +880,6 @@ static int mga_crtc_do_set_base(struct drm_crtc *crtc,
 		goto err_drm_gem_vram_unpin;
 	}
 
-	if (mdev->mfbdev->helper.fb == crtc->primary->fb) {
-		/* if pushing console in kmap it */
-		base = drm_gem_vram_kmap(gbo, true, NULL);
-		if (IS_ERR(base)) {
-			ret = PTR_ERR(base);
-			DRM_ERROR("failed to kmap fbcon\n");
-		}
-	}
-
 	mga_set_start_address(crtc, (u32)gpu_addr);
 
 	return 0;
@@ -1418,14 +1403,9 @@ static void mga_crtc_disable(struct drm_crtc *crtc)
 	DRM_DEBUG_KMS("\n");
 	mga_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
 	if (crtc->primary->fb) {
-		struct mga_device *mdev = crtc->dev->dev_private;
 		struct drm_framebuffer *fb = crtc->primary->fb;
 		struct drm_gem_vram_object *gbo =
 			drm_gem_vram_of_gem(fb->obj[0]);
-
-		/* unmap if console */
-		if (mdev->mfbdev->helper.fb == fb)
-			drm_gem_vram_kunmap(gbo);
 		drm_gem_vram_unpin(gbo);
 	}
 	crtc->primary->fb = NULL;
@@ -1718,7 +1698,6 @@ int mgag200_modeset_init(struct mga_device *mdev)
 {
 	struct drm_encoder *encoder;
 	struct drm_connector *connector;
-	int ret;
 
 	mdev->mode_info.mode_config_initialized = true;
 
@@ -1743,12 +1722,6 @@ int mgag200_modeset_init(struct mga_device *mdev)
 
 	drm_connector_attach_encoder(connector, encoder);
 
-	ret = mgag200_fbdev_init(mdev);
-	if (ret) {
-		DRM_ERROR("mga_fbdev_init failed\n");
-		return ret;
-	}
-
 	return 0;
 }
 
-- 
2.21.0

[PATCH 5/5] drm/mgag200: Replace struct mga_fbdev with generic framebuffer emulation

[Thomas Zimmermann]

This patch replaces mgag200's framebuffer console with DRM's generic
implememtation. All respective code is being removed from the driver.

The console is set up with a shadow buffer. The actual buffer object is
not permanently pinned in video ram, but just another buffer object that
the driver moves in and out of vram as necessary. The driver's function
mga_crtc_do_set_base() used to contain special handling for the framebuffer
console. With the new generic framebuffer, the driver does not need this
code an longer.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/mgag200/Makefile       |   2 +-
 drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
 drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 -------------------------
 drivers/gpu/drm/mgag200/mgag200_main.c |  61 ++---
 drivers/gpu/drm/mgag200/mgag200_mode.c |  27 ---
 5 files changed, 35 insertions(+), 383 deletions(-)
 delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c

diff --git a/drivers/gpu/drm/mgag200/Makefile b/drivers/gpu/drm/mgag200/Makefile
index 98d204408bd0..04b281bcf655 100644
--- a/drivers/gpu/drm/mgag200/Makefile
+++ b/drivers/gpu/drm/mgag200/Makefile
@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
 mgag200-y   := mgag200_main.o mgag200_mode.o mgag200_cursor.o \
-	mgag200_drv.o mgag200_fb.o mgag200_i2c.o mgag200_ttm.o
+	mgag200_drv.o mgag200_i2c.o mgag200_ttm.o
 
 obj-$(CONFIG_DRM_MGAG200) += mgag200.o
diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.h b/drivers/gpu/drm/mgag200/mgag200_drv.h
index 3ab27f1053c1..1c93f8dc08c7 100644
--- a/drivers/gpu/drm/mgag200/mgag200_drv.h
+++ b/drivers/gpu/drm/mgag200/mgag200_drv.h
@@ -99,14 +99,6 @@
 #define to_mga_encoder(x) container_of(x, struct mga_encoder, base)
 #define to_mga_connector(x) container_of(x, struct mga_connector, base)
 
-struct mga_fbdev {
-	struct drm_fb_helper helper; /* must be first */
-	void *sysram;
-	int size;
-	int x1, y1, x2, y2; /* dirty rect */
-	spinlock_t dirty_lock;
-};
-
 struct mga_crtc {
 	struct drm_crtc base;
 	u8 lut_r[256], lut_g[256], lut_b[256];
@@ -180,7 +172,6 @@ struct mga_device {
 	struct mga_mc			mc;
 	struct mga_mode_info		mode_info;
 
-	struct mga_fbdev *mfbdev;
 	struct mga_cursor cursor;
 
 	bool				suspended;
@@ -201,19 +192,9 @@ struct mga_device {
 int mgag200_modeset_init(struct mga_device *mdev);
 void mgag200_modeset_fini(struct mga_device *mdev);
 
-				/* mgag200_fb.c */
-int mgag200_fbdev_init(struct mga_device *mdev);
-void mgag200_fbdev_fini(struct mga_device *mdev);
-
 				/* mgag200_main.c */
 int mgag200_driver_load(struct drm_device *dev, unsigned long flags);
 void mgag200_driver_unload(struct drm_device *dev);
-int mgag200_gem_create(struct drm_device *dev,
-		   u32 size, bool iskernel,
-		       struct drm_gem_object **obj);
-int mgag200_dumb_create(struct drm_file *file,
-			struct drm_device *dev,
-			struct drm_mode_create_dumb *args);
 
 				/* mgag200_i2c.c */
 struct mga_i2c_chan *mgag200_i2c_create(struct drm_device *dev);
diff --git a/drivers/gpu/drm/mgag200/mgag200_fb.c b/drivers/gpu/drm/mgag200/mgag200_fb.c
deleted file mode 100644
index c77cf1b34c98..000000000000
--- a/drivers/gpu/drm/mgag200/mgag200_fb.c
+++ /dev/null
@@ -1,309 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright 2010 Matt Turner.
- * Copyright 2012 Red Hat
- *
- * Authors: Matthew Garrett
- *          Matt Turner
- *          Dave Airlie
- */
-
-#include <linux/module.h>
-#include <linux/vmalloc.h>
-
-#include <drm/drm_crtc_helper.h>
-#include <drm/drm_fb_helper.h>
-#include <drm/drm_fourcc.h>
-#include <drm/drm_gem_framebuffer_helper.h>
-#include <drm/drm_util.h>
-
-#include "mgag200_drv.h"
-
-static void mga_dirty_update(struct mga_fbdev *mfbdev,
-			     int x, int y, int width, int height)
-{
-	int i;
-	struct drm_gem_vram_object *gbo;
-	int src_offset, dst_offset;
-	int ret;
-	u8 *dst;
-	bool unmap = false;
-	bool store_for_later = false;
-	int x2, y2;
-	unsigned long flags;
-	struct drm_framebuffer *fb = mfbdev->helper.fb;
-	int bpp = fb->format->cpp[0];
-
-	gbo = drm_gem_vram_of_gem(fb->obj[0]);
-
-	if (drm_can_sleep()) {
-		/* We pin the BO so it won't be moved during the
-		 * update. The actual location, video RAM or system
-		 * memory, is not important.
-		 */
-		ret = drm_gem_vram_pin(gbo, 0);
-		if (ret) {
-			if (ret != -EBUSY)
-				return;
-			store_for_later = true;
-		}
-	} else {
-		store_for_later = true;
-	}
-
-	x2 = x + width - 1;
-	y2 = y + height - 1;
-	spin_lock_irqsave(&mfbdev->dirty_lock, flags);
-
-	if (mfbdev->y1 < y)
-		y = mfbdev->y1;
-	if (mfbdev->y2 > y2)
-		y2 = mfbdev->y2;
-	if (mfbdev->x1 < x)
-		x = mfbdev->x1;
-	if (mfbdev->x2 > x2)
-		x2 = mfbdev->x2;
-
-	if (store_for_later) {
-		mfbdev->x1 = x;
-		mfbdev->x2 = x2;
-		mfbdev->y1 = y;
-		mfbdev->y2 = y2;
-		spin_unlock_irqrestore(&mfbdev->dirty_lock, flags);
-		return;
-	}
-
-	mfbdev->x1 = mfbdev->y1 = INT_MAX;
-	mfbdev->x2 = mfbdev->y2 = 0;
-	spin_unlock_irqrestore(&mfbdev->dirty_lock, flags);
-
-	dst = drm_gem_vram_kmap(gbo, false, NULL);
-	if (IS_ERR(dst)) {
-		DRM_ERROR("failed to kmap fb updates\n");
-		goto out;
-	} else if (!dst) {
-		dst = drm_gem_vram_kmap(gbo, true, NULL);
-		if (IS_ERR(dst)) {
-			DRM_ERROR("failed to kmap fb updates\n");
-			goto out;
-		}
-		unmap = true;
-	}
-
-	for (i = y; i <= y2; i++) {
-		/* assume equal stride for now */
-		src_offset = dst_offset = i * fb->pitches[0] + (x * bpp);
-		memcpy_toio(dst + dst_offset, mfbdev->sysram + src_offset,
-			    (x2 - x + 1) * bpp);
-	}
-
-	if (unmap)
-		drm_gem_vram_kunmap(gbo);
-
-out:
-	drm_gem_vram_unpin(gbo);
-}
-
-static void mga_fillrect(struct fb_info *info,
-			 const struct fb_fillrect *rect)
-{
-	struct mga_fbdev *mfbdev = info->par;
-	drm_fb_helper_sys_fillrect(info, rect);
-	mga_dirty_update(mfbdev, rect->dx, rect->dy, rect->width,
-			 rect->height);
-}
-
-static void mga_copyarea(struct fb_info *info,
-			 const struct fb_copyarea *area)
-{
-	struct mga_fbdev *mfbdev = info->par;
-	drm_fb_helper_sys_copyarea(info, area);
-	mga_dirty_update(mfbdev, area->dx, area->dy, area->width,
-			 area->height);
-}
-
-static void mga_imageblit(struct fb_info *info,
-			  const struct fb_image *image)
-{
-	struct mga_fbdev *mfbdev = info->par;
-	drm_fb_helper_sys_imageblit(info, image);
-	mga_dirty_update(mfbdev, image->dx, image->dy, image->width,
-			 image->height);
-}
-
-
-static struct fb_ops mgag200fb_ops = {
-	.owner = THIS_MODULE,
-	.fb_check_var = drm_fb_helper_check_var,
-	.fb_set_par = drm_fb_helper_set_par,
-	.fb_fillrect = mga_fillrect,
-	.fb_copyarea = mga_copyarea,
-	.fb_imageblit = mga_imageblit,
-	.fb_pan_display = drm_fb_helper_pan_display,
-	.fb_blank = drm_fb_helper_blank,
-	.fb_setcmap = drm_fb_helper_setcmap,
-};
-
-static int mgag200fb_create_object(struct mga_fbdev *afbdev,
-				   const struct drm_mode_fb_cmd2 *mode_cmd,
-				   struct drm_gem_object **gobj_p)
-{
-	struct drm_device *dev = afbdev->helper.dev;
-	u32 size;
-	struct drm_gem_object *gobj;
-	int ret = 0;
-
-	size = mode_cmd->pitches[0] * mode_cmd->height;
-	ret = mgag200_gem_create(dev, size, true, &gobj);
-	if (ret)
-		return ret;
-
-	*gobj_p = gobj;
-	return ret;
-}
-
-static int mgag200fb_create(struct drm_fb_helper *helper,
-			   struct drm_fb_helper_surface_size *sizes)
-{
-	struct mga_fbdev *mfbdev =
-		container_of(helper, struct mga_fbdev, helper);
-	struct drm_device *dev = mfbdev->helper.dev;
-	struct drm_mode_fb_cmd2 mode_cmd;
-	struct mga_device *mdev = dev->dev_private;
-	struct fb_info *info;
-	struct drm_framebuffer *fb;
-	struct drm_gem_object *gobj = NULL;
-	int ret;
-	void *sysram;
-	int size;
-
-	mode_cmd.width = sizes->surface_width;
-	mode_cmd.height = sizes->surface_height;
-	mode_cmd.pitches[0] = mode_cmd.width * ((sizes->surface_bpp + 7) / 8);
-
-	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
-							  sizes->surface_depth);
-	size = mode_cmd.pitches[0] * mode_cmd.height;
-
-	ret = mgag200fb_create_object(mfbdev, &mode_cmd, &gobj);
-	if (ret) {
-		DRM_ERROR("failed to create fbcon backing object %d\n", ret);
-		return ret;
-	}
-
-	sysram = vmalloc(size);
-	if (!sysram) {
-		ret = -ENOMEM;
-		goto err_drm_gem_object_put_unlocked;
-	}
-
-	info = drm_fb_helper_alloc_fbi(helper);
-	if (IS_ERR(info)) {
-		ret = PTR_ERR(info);
-		goto err_vfree;
-	}
-
-	fb = drm_gem_fbdev_fb_create(dev, sizes, 0, gobj, NULL);
-	if (IS_ERR(fb)) {
-		ret = PTR_ERR(fb);
-		goto err_vfree;
-	}
-
-	mfbdev->sysram = sysram;
-	mfbdev->size = size;
-
-	/* setup helper */
-	mfbdev->helper.fb = fb;
-
-	info->fbops = &mgag200fb_ops;
-
-	/* setup aperture base/size for vesafb takeover */
-	info->apertures->ranges[0].base = mdev->dev->mode_config.fb_base;
-	info->apertures->ranges[0].size = mdev->mc.vram_size;
-
-	drm_fb_helper_fill_info(info, &mfbdev->helper, sizes);
-
-	info->screen_base = sysram;
-	info->screen_size = size;
-	info->pixmap.flags = FB_PIXMAP_SYSTEM;
-
-	DRM_DEBUG_KMS("allocated %dx%d\n",
-		      fb->width, fb->height);
-
-	return 0;
-
-err_vfree:
-	vfree(sysram);
-err_drm_gem_object_put_unlocked:
-	drm_gem_object_put_unlocked(gobj);
-	return ret;
-}
-
-static int mga_fbdev_destroy(struct drm_device *dev,
-				struct mga_fbdev *mfbdev)
-{
-	drm_fb_helper_unregister_fbi(&mfbdev->helper);
-	drm_fb_helper_fini(&mfbdev->helper);
-	drm_framebuffer_put(mfbdev->helper.fb);
-
-	vfree(mfbdev->sysram);
-
-	return 0;
-}
-
-static const struct drm_fb_helper_funcs mga_fb_helper_funcs = {
-	.fb_probe = mgag200fb_create,
-};
-
-int mgag200_fbdev_init(struct mga_device *mdev)
-{
-	struct mga_fbdev *mfbdev;
-	int ret;
-	int bpp_sel = 32;
-
-	/* prefer 16bpp on low end gpus with limited VRAM */
-	if (IS_G200_SE(mdev) && mdev->mc.vram_size < (2048*1024))
-		bpp_sel = 16;
-
-	mfbdev = devm_kzalloc(mdev->dev->dev, sizeof(struct mga_fbdev), GFP_KERNEL);
-	if (!mfbdev)
-		return -ENOMEM;
-
-	mdev->mfbdev = mfbdev;
-	spin_lock_init(&mfbdev->dirty_lock);
-
-	drm_fb_helper_prepare(mdev->dev, &mfbdev->helper, &mga_fb_helper_funcs);
-
-	ret = drm_fb_helper_init(mdev->dev, &mfbdev->helper,
-				 MGAG200FB_CONN_LIMIT);
-	if (ret)
-		goto err_fb_helper;
-
-	ret = drm_fb_helper_single_add_all_connectors(&mfbdev->helper);
-	if (ret)
-		goto err_fb_setup;
-
-	/* disable all the possible outputs/crtcs before entering KMS mode */
-	drm_helper_disable_unused_functions(mdev->dev);
-
-	ret = drm_fb_helper_initial_config(&mfbdev->helper, bpp_sel);
-	if (ret)
-		goto err_fb_setup;
-
-	return 0;
-
-err_fb_setup:
-	drm_fb_helper_fini(&mfbdev->helper);
-err_fb_helper:
-	mdev->mfbdev = NULL;
-
-	return ret;
-}
-
-void mgag200_fbdev_fini(struct mga_device *mdev)
-{
-	if (!mdev->mfbdev)
-		return;
-
-	mga_fbdev_destroy(mdev->dev, mdev->mfbdev);
-}
diff --git a/drivers/gpu/drm/mgag200/mgag200_main.c b/drivers/gpu/drm/mgag200/mgag200_main.c
index b10f7265b5c4..6d943a008752 100644
--- a/drivers/gpu/drm/mgag200/mgag200_main.c
+++ b/drivers/gpu/drm/mgag200/mgag200_main.c
@@ -14,8 +14,33 @@
 
 #include "mgag200_drv.h"
 
+static int mga_framebuffer_dirtyfb(struct drm_framebuffer *fb,
+				   struct drm_file *file_priv,
+				   unsigned int flags,
+				   unsigned int color,
+				   struct drm_clip_rect *clips,
+				   unsigned int num_clips)
+{
+	/* empty placeholder function to enable fbcon shadow buffer */
+	return 0;
+}
+
+static const struct drm_framebuffer_funcs mga_framebuffer_funcs = {
+	.destroy	= drm_gem_fb_destroy,
+	.create_handle	= drm_gem_fb_create_handle,
+	.dirty		= mga_framebuffer_dirtyfb,
+};
+
+static struct drm_framebuffer *
+mga_mode_config_funcs_fb_create(struct drm_device *dev, struct drm_file *file,
+				const struct drm_mode_fb_cmd2 *mode_cmd)
+{
+	return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
+					    &mga_framebuffer_funcs);
+}
+
 static const struct drm_mode_config_funcs mga_mode_funcs = {
-	.fb_create = drm_gem_fb_create
+	.fb_create = mga_mode_config_funcs_fb_create
 };
 
 static int mga_probe_vram(struct mga_device *mdev, void __iomem *mem)
@@ -162,7 +187,7 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
 	if (IS_G200_SE(mdev) && mdev->mc.vram_size < (2048*1024))
 		dev->mode_config.preferred_depth = 16;
 	else
-		dev->mode_config.preferred_depth = 24;
+		dev->mode_config.preferred_depth = 32;
 	dev->mode_config.prefer_shadow = 1;
 
 	r = mgag200_modeset_init(mdev);
@@ -186,6 +211,13 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
 	}
 	mdev->cursor.pixels_current = NULL;
 
+	r = drm_fbdev_generic_setup(mdev->dev, 0);
+	if (r) {
+		dev_err(&dev->pdev->dev,
+			"drm_fbdev_generic_setup failed: %d\n", r);
+		goto err_modeset;
+	}
+
 	return 0;
 
 err_modeset:
@@ -204,32 +236,7 @@ void mgag200_driver_unload(struct drm_device *dev)
 	if (mdev == NULL)
 		return;
 	mgag200_modeset_fini(mdev);
-	mgag200_fbdev_fini(mdev);
 	drm_mode_config_cleanup(dev);
 	mgag200_mm_fini(mdev);
 	dev->dev_private = NULL;
 }
-
-int mgag200_gem_create(struct drm_device *dev,
-		   u32 size, bool iskernel,
-		   struct drm_gem_object **obj)
-{
-	struct drm_gem_vram_object *gbo;
-	int ret;
-
-	*obj = NULL;
-
-	size = roundup(size, PAGE_SIZE);
-	if (size == 0)
-		return -EINVAL;
-
-	gbo = drm_gem_vram_create(dev, &dev->vram_mm->bdev, size, 0, false);
-	if (IS_ERR(gbo)) {
-		ret = PTR_ERR(gbo);
-		if (ret != -ERESTARTSYS)
-			DRM_ERROR("failed to allocate GEM object\n");
-		return ret;
-	}
-	*obj = &gbo->gem;
-	return 0;
-}
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index a7cef78d426f..822f2a13748f 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -860,18 +860,12 @@ static int mga_crtc_do_set_base(struct drm_crtc *crtc,
 				struct drm_framebuffer *fb,
 				int x, int y, int atomic)
 {
-	struct mga_device *mdev = crtc->dev->dev_private;
 	struct drm_gem_vram_object *gbo;
 	int ret;
 	s64 gpu_addr;
-	void *base;
 
 	if (!atomic && fb) {
 		gbo = drm_gem_vram_of_gem(fb->obj[0]);
-
-		/* unmap if console */
-		if (mdev->mfbdev->helper.fb == fb)
-			drm_gem_vram_kunmap(gbo);
 		drm_gem_vram_unpin(gbo);
 	}
 
@@ -886,15 +880,6 @@ static int mga_crtc_do_set_base(struct drm_crtc *crtc,
 		goto err_drm_gem_vram_unpin;
 	}
 
-	if (mdev->mfbdev->helper.fb == crtc->primary->fb) {
-		/* if pushing console in kmap it */
-		base = drm_gem_vram_kmap(gbo, true, NULL);
-		if (IS_ERR(base)) {
-			ret = PTR_ERR(base);
-			DRM_ERROR("failed to kmap fbcon\n");
-		}
-	}
-
 	mga_set_start_address(crtc, (u32)gpu_addr);
 
 	return 0;
@@ -1418,14 +1403,9 @@ static void mga_crtc_disable(struct drm_crtc *crtc)
 	DRM_DEBUG_KMS("\n");
 	mga_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
 	if (crtc->primary->fb) {
-		struct mga_device *mdev = crtc->dev->dev_private;
 		struct drm_framebuffer *fb = crtc->primary->fb;
 		struct drm_gem_vram_object *gbo =
 			drm_gem_vram_of_gem(fb->obj[0]);
-
-		/* unmap if console */
-		if (mdev->mfbdev->helper.fb == fb)
-			drm_gem_vram_kunmap(gbo);
 		drm_gem_vram_unpin(gbo);
 	}
 	crtc->primary->fb = NULL;
@@ -1718,7 +1698,6 @@ int mgag200_modeset_init(struct mga_device *mdev)
 {
 	struct drm_encoder *encoder;
 	struct drm_connector *connector;
-	int ret;
 
 	mdev->mode_info.mode_config_initialized = true;
 
@@ -1743,12 +1722,6 @@ int mgag200_modeset_init(struct mga_device *mdev)
 
 	drm_connector_attach_encoder(connector, encoder);
 
-	ret = mgag200_fbdev_init(mdev);
-	if (ret) {
-		DRM_ERROR("mga_fbdev_init failed\n");
-		return ret;
-	}
-
 	return 0;
 }
 
-- 
2.21.0

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Re: [PATCH 1/5] drm/client: Support unmapping of DRM client buffers

[Noralf Trønnes]

Den 03.07.2019 10.32, skrev Thomas Zimmermann:
> DRM clients, such as the fbdev emulation, have their buffer objects
> mapped by default. Mapping a buffer implicitly prevents its relocation.
> Hence, the buffer may permanently consume video memory while it's
> allocated. This is a problem for drivers of low-memory devices, such as
> ast, mgag200 or older framebuffer hardware, which will then not have
> enough memory to display other content (e.g., X11).
> 
> This patch introduces drm_client_buffer_vmap() and _vunmap(). Internal
> DRM clients can use these functions to unmap and remap buffer objects
> as needed.
> 
> There's no reference counting for vmap operations. Callers are expected
> to either keep buffers mapped (as it is now), or call vmap and vunmap
> in pairs around code that accesses the mapped memory.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>  drivers/gpu/drm/drm_client.c | 71 +++++++++++++++++++++++++++++++-----
>  include/drm/drm_client.h     |  3 ++
>  2 files changed, 64 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
> index 410572f14257..d04660c4470a 100644
> --- a/drivers/gpu/drm/drm_client.c
> +++ b/drivers/gpu/drm/drm_client.c
> @@ -235,7 +235,8 @@ static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
>  {
>  	struct drm_device *dev = buffer->client->dev;
>  
> -	drm_gem_vunmap(buffer->gem, buffer->vaddr);
> +	if (buffer->vaddr)

No need for this, drm_gem_vunmap() has a NULL check.

> +		drm_gem_vunmap(buffer->gem, buffer->vaddr);
>  
>  	if (buffer->gem)
>  		drm_gem_object_put_unlocked(buffer->gem);
> @@ -281,6 +282,43 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
>  
>  	buffer->gem = obj;
>  
> +	vaddr = drm_client_buffer_vmap(buffer);

I think we should change this and _not_ vmap on buffer creation.
Eventually we'll get bootsplash and console clients and they will also
have to deal with these low memory devices. AFAICS the only client that
will need a virtual address at all times is the fbdev client when it
doesn't use a shadow buffer.

> +	if (IS_ERR(vaddr)) {
> +		ret = PTR_ERR(vaddr);
> +		goto err_delete;
> +	}
> +
> +	return buffer;
> +
> +err_delete:
> +	drm_client_buffer_delete(buffer);
> +
> +	return ERR_PTR(ret);
> +}
> +
> +/**
> + * drm_client_buffer_vmap - Map DRM client buffer into address space
> + * @buffer: DRM client buffer
> + *
> + * This function maps a client buffer into kernel address space. If the
> + * buffer is already mapped, it returns the mapping's address.
> + *
> + * Client buffer mappings are not ref'counted. Each call to
> + * drm_client_buffer_vmap() should be followed by a call to
> + * drm_client_buffer_vunmap(); or the client buffer should be mapped
> + * throughout its lifetime. The latter is the default.
> + *
> + * Returns:
> + *	The mapped memory's address
> + */
> +void *
> +drm_client_buffer_vmap(struct drm_client_buffer *buffer)
> +{
> +	void *vaddr;
> +
> +	if (buffer->vaddr)
> +		return buffer->vaddr;
> +
>  	/*
>  	 * FIXME: The dependency on GEM here isn't required, we could
>  	 * convert the driver handle to a dma-buf instead and use the
> @@ -289,21 +327,34 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
>  	 * fd_install step out of the driver backend hooks, to make that
>  	 * final step optional for internal users.
>  	 */
> -	vaddr = drm_gem_vmap(obj);
> -	if (IS_ERR(vaddr)) {
> -		ret = PTR_ERR(vaddr);
> -		goto err_delete;
> -	}
> +	vaddr = drm_gem_vmap(buffer->gem);
> +	if (IS_ERR(vaddr))
> +		return vaddr;
>  
>  	buffer->vaddr = vaddr;
>  
> -	return buffer;
> +	return vaddr;
> +}
> +EXPORT_SYMBOL(drm_client_buffer_vmap);
>  
> -err_delete:
> -	drm_client_buffer_delete(buffer);
> +/**
> + * drm_client_buffer_vunmap - Unmap DRM client buffer
> + * @buffer: DRM client buffer
> + *
> + * This function removes a client buffer's memory mmapping. This
> + * function is only required by clients that manage their buffers
> + * by themselves. By default, DRM client buffers are mapped throughout
> + * their entire lifetime.
> + */
> +void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
> +{
> +	if (!buffer->vaddr)

No need for a NULL check here either.

Noralf.

> +		return;
>  
> -	return ERR_PTR(ret);
> +	drm_gem_vunmap(buffer->gem, buffer->vaddr);
> +	buffer->vaddr = NULL;
>  }
> +EXPORT_SYMBOL(drm_client_buffer_vunmap);
>  
>  static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
>  {
> diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
> index 72d51d1e9dd9..e1db1d9da0bf 100644
> --- a/include/drm/drm_client.h
> +++ b/include/drm/drm_client.h
> @@ -149,6 +149,9 @@ struct drm_client_buffer {
>  struct drm_client_buffer *
>  drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format);
>  void drm_client_framebuffer_delete(struct drm_client_buffer *buffer);
> +void *
> +drm_client_buffer_vmap(struct drm_client_buffer *buffer);
> +void drm_client_buffer_vunmap(struct drm_client_buffer *buffer);
>  
>  int drm_client_modeset_create(struct drm_client_dev *client);
>  void drm_client_modeset_free(struct drm_client_dev *client);
> 

Re: [PATCH 1/5] drm/client: Support unmapping of DRM client buffers

[Noralf Trønnes]

Den 03.07.2019 10.32, skrev Thomas Zimmermann:
> DRM clients, such as the fbdev emulation, have their buffer objects
> mapped by default. Mapping a buffer implicitly prevents its relocation.
> Hence, the buffer may permanently consume video memory while it's
> allocated. This is a problem for drivers of low-memory devices, such as
> ast, mgag200 or older framebuffer hardware, which will then not have
> enough memory to display other content (e.g., X11).
> 
> This patch introduces drm_client_buffer_vmap() and _vunmap(). Internal
> DRM clients can use these functions to unmap and remap buffer objects
> as needed.
> 
> There's no reference counting for vmap operations. Callers are expected
> to either keep buffers mapped (as it is now), or call vmap and vunmap
> in pairs around code that accesses the mapped memory.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>  drivers/gpu/drm/drm_client.c | 71 +++++++++++++++++++++++++++++++-----
>  include/drm/drm_client.h     |  3 ++
>  2 files changed, 64 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
> index 410572f14257..d04660c4470a 100644
> --- a/drivers/gpu/drm/drm_client.c
> +++ b/drivers/gpu/drm/drm_client.c
> @@ -235,7 +235,8 @@ static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
>  {
>  	struct drm_device *dev = buffer->client->dev;
>  
> -	drm_gem_vunmap(buffer->gem, buffer->vaddr);
> +	if (buffer->vaddr)

No need for this, drm_gem_vunmap() has a NULL check.

> +		drm_gem_vunmap(buffer->gem, buffer->vaddr);
>  
>  	if (buffer->gem)
>  		drm_gem_object_put_unlocked(buffer->gem);
> @@ -281,6 +282,43 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
>  
>  	buffer->gem = obj;
>  
> +	vaddr = drm_client_buffer_vmap(buffer);

I think we should change this and _not_ vmap on buffer creation.
Eventually we'll get bootsplash and console clients and they will also
have to deal with these low memory devices. AFAICS the only client that
will need a virtual address at all times is the fbdev client when it
doesn't use a shadow buffer.

> +	if (IS_ERR(vaddr)) {
> +		ret = PTR_ERR(vaddr);
> +		goto err_delete;
> +	}
> +
> +	return buffer;
> +
> +err_delete:
> +	drm_client_buffer_delete(buffer);
> +
> +	return ERR_PTR(ret);
> +}
> +
> +/**
> + * drm_client_buffer_vmap - Map DRM client buffer into address space
> + * @buffer: DRM client buffer
> + *
> + * This function maps a client buffer into kernel address space. If the
> + * buffer is already mapped, it returns the mapping's address.
> + *
> + * Client buffer mappings are not ref'counted. Each call to
> + * drm_client_buffer_vmap() should be followed by a call to
> + * drm_client_buffer_vunmap(); or the client buffer should be mapped
> + * throughout its lifetime. The latter is the default.
> + *
> + * Returns:
> + *	The mapped memory's address
> + */
> +void *
> +drm_client_buffer_vmap(struct drm_client_buffer *buffer)
> +{
> +	void *vaddr;
> +
> +	if (buffer->vaddr)
> +		return buffer->vaddr;
> +
>  	/*
>  	 * FIXME: The dependency on GEM here isn't required, we could
>  	 * convert the driver handle to a dma-buf instead and use the
> @@ -289,21 +327,34 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
>  	 * fd_install step out of the driver backend hooks, to make that
>  	 * final step optional for internal users.
>  	 */
> -	vaddr = drm_gem_vmap(obj);
> -	if (IS_ERR(vaddr)) {
> -		ret = PTR_ERR(vaddr);
> -		goto err_delete;
> -	}
> +	vaddr = drm_gem_vmap(buffer->gem);
> +	if (IS_ERR(vaddr))
> +		return vaddr;
>  
>  	buffer->vaddr = vaddr;
>  
> -	return buffer;
> +	return vaddr;
> +}
> +EXPORT_SYMBOL(drm_client_buffer_vmap);
>  
> -err_delete:
> -	drm_client_buffer_delete(buffer);
> +/**
> + * drm_client_buffer_vunmap - Unmap DRM client buffer
> + * @buffer: DRM client buffer
> + *
> + * This function removes a client buffer's memory mmapping. This
> + * function is only required by clients that manage their buffers
> + * by themselves. By default, DRM client buffers are mapped throughout
> + * their entire lifetime.
> + */
> +void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
> +{
> +	if (!buffer->vaddr)

No need for a NULL check here either.

Noralf.

> +		return;
>  
> -	return ERR_PTR(ret);
> +	drm_gem_vunmap(buffer->gem, buffer->vaddr);
> +	buffer->vaddr = NULL;
>  }
> +EXPORT_SYMBOL(drm_client_buffer_vunmap);
>  
>  static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
>  {
> diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
> index 72d51d1e9dd9..e1db1d9da0bf 100644
> --- a/include/drm/drm_client.h
> +++ b/include/drm/drm_client.h
> @@ -149,6 +149,9 @@ struct drm_client_buffer {
>  struct drm_client_buffer *
>  drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format);
>  void drm_client_framebuffer_delete(struct drm_client_buffer *buffer);
> +void *
> +drm_client_buffer_vmap(struct drm_client_buffer *buffer);
> +void drm_client_buffer_vunmap(struct drm_client_buffer *buffer);
>  
>  int drm_client_modeset_create(struct drm_client_dev *client);
>  void drm_client_modeset_free(struct drm_client_dev *client);
> 
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Re: [PATCH 3/5] drm/ast: Replace struct ast_fbdev with generic framebuffer emulation

[Noralf Trønnes]

Den 03.07.2019 10.33, skrev Thomas Zimmermann:
> This patch replaces ast's framebuffer console with DRM's generic
> implememtation. All respective code is being removed from the driver.
> 
> The console is set up with a shadow buffer. The actual buffer object is
> not permanently pinned in video ram, but just another buffer object that
> the driver moves in and out of vram as necessary. The driver's function
> ast_crtc_do_set_base() used to contain special handling for the framebuffer
> console. With the new generic framebuffer, the driver does not need this
> code an longer.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>  drivers/gpu/drm/ast/Makefile   |   2 +-
>  drivers/gpu/drm/ast/ast_drv.c  |  22 ++-
>  drivers/gpu/drm/ast/ast_drv.h  |  17 --
>  drivers/gpu/drm/ast/ast_fb.c   | 341 ---------------------------------
>  drivers/gpu/drm/ast/ast_main.c |  30 ++-
>  drivers/gpu/drm/ast/ast_mode.c |  21 --
>  6 files changed, 41 insertions(+), 392 deletions(-)
>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
> 
> diff --git a/drivers/gpu/drm/ast/Makefile b/drivers/gpu/drm/ast/Makefile
> index b086dae17013..561f7c4199e4 100644
> --- a/drivers/gpu/drm/ast/Makefile
> +++ b/drivers/gpu/drm/ast/Makefile
> @@ -3,6 +3,6 @@
>  # Makefile for the drm device driver.  This driver provides support for the
>  # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
>  
> -ast-y := ast_drv.o ast_main.o ast_mode.o ast_fb.o ast_ttm.o ast_post.o ast_dp501.o
> +ast-y := ast_drv.o ast_main.o ast_mode.o ast_ttm.o ast_post.o ast_dp501.o
>  
>  obj-$(CONFIG_DRM_AST) := ast.o
> diff --git a/drivers/gpu/drm/ast/ast_drv.c b/drivers/gpu/drm/ast/ast_drv.c
> index 3811997e78c4..75f55ac1a218 100644
> --- a/drivers/gpu/drm/ast/ast_drv.c
> +++ b/drivers/gpu/drm/ast/ast_drv.c
> @@ -103,25 +103,29 @@ static int ast_drm_freeze(struct drm_device *dev)
>  
>  	pci_save_state(dev->pdev);
>  
> -	console_lock();
> -	ast_fbdev_set_suspend(dev, 1);
> -	console_unlock();
> +	if (dev->fb_helper) {
> +		console_lock();
> +		drm_fb_helper_set_suspend(dev->fb_helper, 1);
> +		console_unlock();
> +	}

You can call drm_fb_helper_set_suspend_unlocked() unconditionally here
and it will do the NULL check and locking for you.

> +
>  	return 0;
>  }
>  
>  static int ast_drm_thaw(struct drm_device *dev)
>  {
> -	int error = 0;
> -
>  	ast_post_gpu(dev);
>  
>  	drm_mode_config_reset(dev);
>  	drm_helper_resume_force_mode(dev);
>  
> -	console_lock();
> -	ast_fbdev_set_suspend(dev, 0);
> -	console_unlock();
> -	return error;
> +	if (dev->fb_helper) {
> +		console_lock();
> +		drm_fb_helper_set_suspend(dev->fb_helper, 0);
> +		console_unlock();
> +	}

Same here.

With that:

Acked-by: Noralf Trønnes <noralf@tronnes.org>

> +
> +	return 0;
>  }
>  
>  static int ast_drm_resume(struct drm_device *dev)
> diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
> index ca794a3fcf8f..907d7480b7ba 100644
> --- a/drivers/gpu/drm/ast/ast_drv.h
> +++ b/drivers/gpu/drm/ast/ast_drv.h
> @@ -81,8 +81,6 @@ enum ast_tx_chip {
>  #define AST_DRAM_4Gx16   7
>  #define AST_DRAM_8Gx16   8
>  
> -struct ast_fbdev;
> -
>  struct ast_private {
>  	struct drm_device *dev;
>  
> @@ -96,8 +94,6 @@ struct ast_private {
>  	uint32_t mclk;
>  	uint32_t vram_size;
>  
> -	struct ast_fbdev *fbdev;
> -
>  	int fb_mtrr;
>  
>  	struct drm_gem_object *cursor_cache;
> @@ -239,14 +235,6 @@ struct ast_encoder {
>  	struct drm_encoder base;
>  };
>  
> -struct ast_fbdev {
> -	struct drm_fb_helper helper; /* must be first */
> -	void *sysram;
> -	int size;
> -	int x1, y1, x2, y2; /* dirty rect */
> -	spinlock_t dirty_lock;
> -};
> -
>  #define to_ast_crtc(x) container_of(x, struct ast_crtc, base)
>  #define to_ast_connector(x) container_of(x, struct ast_connector, base)
>  #define to_ast_encoder(x) container_of(x, struct ast_encoder, base)
> @@ -289,11 +277,6 @@ struct ast_vbios_mode_info {
>  extern int ast_mode_init(struct drm_device *dev);
>  extern void ast_mode_fini(struct drm_device *dev);
>  
> -int ast_fbdev_init(struct drm_device *dev);
> -void ast_fbdev_fini(struct drm_device *dev);
> -void ast_fbdev_set_suspend(struct drm_device *dev, int state);
> -void ast_fbdev_set_base(struct ast_private *ast, unsigned long gpu_addr);
> -
>  #define AST_MM_ALIGN_SHIFT 4
>  #define AST_MM_ALIGN_MASK ((1 << AST_MM_ALIGN_SHIFT) - 1)
>  
> diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c
> deleted file mode 100644
> index a849e58b40bc..000000000000
> --- a/drivers/gpu/drm/ast/ast_fb.c
> +++ /dev/null
> @@ -1,341 +0,0 @@
> -/*
> - * Copyright 2012 Red Hat Inc.
> - *
> - * Permission is hereby granted, free of charge, to any person obtaining a
> - * copy of this software and associated documentation files (the
> - * "Software"), to deal in the Software without restriction, including
> - * without limitation the rights to use, copy, modify, merge, publish,
> - * distribute, sub license, and/or sell copies of the Software, and to
> - * permit persons to whom the Software is furnished to do so, subject to
> - * the following conditions:
> - *
> - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> - * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
> - * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
> - * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
> - * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
> - * USE OR OTHER DEALINGS IN THE SOFTWARE.
> - *
> - * The above copyright notice and this permission notice (including the
> - * next paragraph) shall be included in all copies or substantial portions
> - * of the Software.
> - *
> - */
> -/*
> - * Authors: Dave Airlie <airlied@redhat.com>
> - */
> -#include <linux/module.h>
> -#include <linux/kernel.h>
> -#include <linux/errno.h>
> -#include <linux/string.h>
> -#include <linux/mm.h>
> -#include <linux/tty.h>
> -#include <linux/sysrq.h>
> -#include <linux/delay.h>
> -#include <linux/init.h>
> -
> -
> -#include <drm/drmP.h>
> -#include <drm/drm_crtc.h>
> -#include <drm/drm_crtc_helper.h>
> -#include <drm/drm_fb_helper.h>
> -#include <drm/drm_gem_framebuffer_helper.h>
> -#include <drm/drm_util.h>
> -
> -#include "ast_drv.h"
> -
> -static void ast_dirty_update(struct ast_fbdev *afbdev,
> -			     int x, int y, int width, int height)
> -{
> -	int i;
> -	struct drm_gem_vram_object *gbo;
> -	int src_offset, dst_offset;
> -	int ret;
> -	u8 *dst;
> -	bool unmap = false;
> -	bool store_for_later = false;
> -	int x2, y2;
> -	unsigned long flags;
> -	struct drm_framebuffer *fb = afbdev->helper.fb;
> -	int bpp = fb->format->cpp[0];
> -
> -	gbo = drm_gem_vram_of_gem(fb->obj[0]);
> -
> -	if (drm_can_sleep()) {
> -		/* We pin the BO so it won't be moved during the
> -		 * update. The actual location, video RAM or system
> -		 * memory, is not important.
> -		 */
> -		ret = drm_gem_vram_pin(gbo, 0);
> -		if (ret) {
> -			if (ret != -EBUSY)
> -				return;
> -			store_for_later = true;
> -		}
> -	} else {
> -		store_for_later = true;
> -	}
> -
> -	x2 = x + width - 1;
> -	y2 = y + height - 1;
> -	spin_lock_irqsave(&afbdev->dirty_lock, flags);
> -
> -	if (afbdev->y1 < y)
> -		y = afbdev->y1;
> -	if (afbdev->y2 > y2)
> -		y2 = afbdev->y2;
> -	if (afbdev->x1 < x)
> -		x = afbdev->x1;
> -	if (afbdev->x2 > x2)
> -		x2 = afbdev->x2;
> -
> -	if (store_for_later) {
> -		afbdev->x1 = x;
> -		afbdev->x2 = x2;
> -		afbdev->y1 = y;
> -		afbdev->y2 = y2;
> -		spin_unlock_irqrestore(&afbdev->dirty_lock, flags);
> -		return;
> -	}
> -
> -	afbdev->x1 = afbdev->y1 = INT_MAX;
> -	afbdev->x2 = afbdev->y2 = 0;
> -	spin_unlock_irqrestore(&afbdev->dirty_lock, flags);
> -
> -	dst = drm_gem_vram_kmap(gbo, false, NULL);
> -	if (IS_ERR(dst)) {
> -		DRM_ERROR("failed to kmap fb updates\n");
> -		goto out;
> -	} else if (!dst) {
> -		dst = drm_gem_vram_kmap(gbo, true, NULL);
> -		if (IS_ERR(dst)) {
> -			DRM_ERROR("failed to kmap fb updates\n");
> -			goto out;
> -		}
> -		unmap = true;
> -	}
> -
> -	for (i = y; i <= y2; i++) {
> -		/* assume equal stride for now */
> -		src_offset = dst_offset = i * fb->pitches[0] + (x * bpp);
> -		memcpy_toio(dst + dst_offset, afbdev->sysram + src_offset,
> -			    (x2 - x + 1) * bpp);
> -	}
> -
> -	if (unmap)
> -		drm_gem_vram_kunmap(gbo);
> -
> -out:
> -	drm_gem_vram_unpin(gbo);
> -}
> -
> -static void ast_fillrect(struct fb_info *info,
> -			 const struct fb_fillrect *rect)
> -{
> -	struct ast_fbdev *afbdev = info->par;
> -	drm_fb_helper_sys_fillrect(info, rect);
> -	ast_dirty_update(afbdev, rect->dx, rect->dy, rect->width,
> -			 rect->height);
> -}
> -
> -static void ast_copyarea(struct fb_info *info,
> -			 const struct fb_copyarea *area)
> -{
> -	struct ast_fbdev *afbdev = info->par;
> -	drm_fb_helper_sys_copyarea(info, area);
> -	ast_dirty_update(afbdev, area->dx, area->dy, area->width,
> -			 area->height);
> -}
> -
> -static void ast_imageblit(struct fb_info *info,
> -			  const struct fb_image *image)
> -{
> -	struct ast_fbdev *afbdev = info->par;
> -	drm_fb_helper_sys_imageblit(info, image);
> -	ast_dirty_update(afbdev, image->dx, image->dy, image->width,
> -			 image->height);
> -}
> -
> -static struct fb_ops astfb_ops = {
> -	.owner = THIS_MODULE,
> -	.fb_check_var = drm_fb_helper_check_var,
> -	.fb_set_par = drm_fb_helper_set_par,
> -	.fb_fillrect = ast_fillrect,
> -	.fb_copyarea = ast_copyarea,
> -	.fb_imageblit = ast_imageblit,
> -	.fb_pan_display = drm_fb_helper_pan_display,
> -	.fb_blank = drm_fb_helper_blank,
> -	.fb_setcmap = drm_fb_helper_setcmap,
> -};
> -
> -static int astfb_create_object(struct ast_fbdev *afbdev,
> -			       const struct drm_mode_fb_cmd2 *mode_cmd,
> -			       struct drm_gem_object **gobj_p)
> -{
> -	struct drm_device *dev = afbdev->helper.dev;
> -	u32 size;
> -	struct drm_gem_object *gobj;
> -	int ret = 0;
> -
> -	size = mode_cmd->pitches[0] * mode_cmd->height;
> -	ret = ast_gem_create(dev, size, true, &gobj);
> -	if (ret)
> -		return ret;
> -
> -	*gobj_p = gobj;
> -	return ret;
> -}
> -
> -static int astfb_create(struct drm_fb_helper *helper,
> -			struct drm_fb_helper_surface_size *sizes)
> -{
> -	struct ast_fbdev *afbdev =
> -		container_of(helper, struct ast_fbdev, helper);
> -	struct drm_device *dev = afbdev->helper.dev;
> -	struct drm_mode_fb_cmd2 mode_cmd;
> -	struct drm_framebuffer *fb;
> -	struct fb_info *info;
> -	int size, ret;
> -	void *sysram;
> -	struct drm_gem_object *gobj = NULL;
> -	mode_cmd.width = sizes->surface_width;
> -	mode_cmd.height = sizes->surface_height;
> -	mode_cmd.pitches[0] = mode_cmd.width * ((sizes->surface_bpp + 7)/8);
> -
> -	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
> -							  sizes->surface_depth);
> -
> -	size = mode_cmd.pitches[0] * mode_cmd.height;
> -
> -	ret = astfb_create_object(afbdev, &mode_cmd, &gobj);
> -	if (ret) {
> -		DRM_ERROR("failed to create fbcon backing object %d\n", ret);
> -		return ret;
> -	}
> -
> -	sysram = vmalloc(size);
> -	if (!sysram)
> -		return -ENOMEM;
> -
> -	info = drm_fb_helper_alloc_fbi(helper);
> -	if (IS_ERR(info)) {
> -		ret = PTR_ERR(info);
> -		goto out;
> -	}
> -	fb = drm_gem_fbdev_fb_create(dev, sizes, 0, gobj, NULL);
> -	if (IS_ERR(fb)) {
> -		ret = PTR_ERR(fb);
> -		goto out;
> -	}
> -
> -	afbdev->sysram = sysram;
> -	afbdev->size = size;
> -
> -	afbdev->helper.fb = fb;
> -
> -	info->fbops = &astfb_ops;
> -
> -	info->apertures->ranges[0].base = pci_resource_start(dev->pdev, 0);
> -	info->apertures->ranges[0].size = pci_resource_len(dev->pdev, 0);
> -
> -	drm_fb_helper_fill_info(info, &afbdev->helper, sizes);
> -
> -	info->screen_base = sysram;
> -	info->screen_size = size;
> -
> -	info->pixmap.flags = FB_PIXMAP_SYSTEM;
> -
> -	DRM_DEBUG_KMS("allocated %dx%d\n",
> -		      fb->width, fb->height);
> -
> -	return 0;
> -
> -out:
> -	vfree(sysram);
> -	return ret;
> -}
> -
> -static const struct drm_fb_helper_funcs ast_fb_helper_funcs = {
> -	.fb_probe = astfb_create,
> -};
> -
> -static void ast_fbdev_destroy(struct drm_device *dev,
> -			      struct ast_fbdev *afbdev)
> -{
> -	drm_helper_force_disable_all(dev);
> -	drm_fb_helper_unregister_fbi(&afbdev->helper);
> -
> -	drm_fb_helper_fini(&afbdev->helper);
> -	drm_framebuffer_put(afbdev->helper.fb);
> -
> -	vfree(afbdev->sysram);
> -}
> -
> -int ast_fbdev_init(struct drm_device *dev)
> -{
> -	struct ast_private *ast = dev->dev_private;
> -	struct ast_fbdev *afbdev;
> -	int ret;
> -
> -	afbdev = kzalloc(sizeof(struct ast_fbdev), GFP_KERNEL);
> -	if (!afbdev)
> -		return -ENOMEM;
> -
> -	ast->fbdev = afbdev;
> -	spin_lock_init(&afbdev->dirty_lock);
> -
> -	drm_fb_helper_prepare(dev, &afbdev->helper, &ast_fb_helper_funcs);
> -
> -	ret = drm_fb_helper_init(dev, &afbdev->helper, 1);
> -	if (ret)
> -		goto free;
> -
> -	ret = drm_fb_helper_single_add_all_connectors(&afbdev->helper);
> -	if (ret)
> -		goto fini;
> -
> -	/* disable all the possible outputs/crtcs before entering KMS mode */
> -	drm_helper_disable_unused_functions(dev);
> -
> -	ret = drm_fb_helper_initial_config(&afbdev->helper, 32);
> -	if (ret)
> -		goto fini;
> -
> -	return 0;
> -
> -fini:
> -	drm_fb_helper_fini(&afbdev->helper);
> -free:
> -	kfree(afbdev);
> -	return ret;
> -}
> -
> -void ast_fbdev_fini(struct drm_device *dev)
> -{
> -	struct ast_private *ast = dev->dev_private;
> -
> -	if (!ast->fbdev)
> -		return;
> -
> -	ast_fbdev_destroy(dev, ast->fbdev);
> -	kfree(ast->fbdev);
> -	ast->fbdev = NULL;
> -}
> -
> -void ast_fbdev_set_suspend(struct drm_device *dev, int state)
> -{
> -	struct ast_private *ast = dev->dev_private;
> -
> -	if (!ast->fbdev)
> -		return;
> -
> -	drm_fb_helper_set_suspend(&ast->fbdev->helper, state);
> -}
> -
> -void ast_fbdev_set_base(struct ast_private *ast, unsigned long gpu_addr)
> -{
> -	ast->fbdev->helper.fbdev->fix.smem_start =
> -		ast->fbdev->helper.fbdev->apertures->ranges[0].base + gpu_addr;
> -	ast->fbdev->helper.fbdev->fix.smem_len = ast->vram_size - gpu_addr;
> -}
> diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
> index 1bd61696e509..78e8e20ff577 100644
> --- a/drivers/gpu/drm/ast/ast_main.c
> +++ b/drivers/gpu/drm/ast/ast_main.c
> @@ -383,8 +383,33 @@ static int ast_get_dram_info(struct drm_device *dev)
>  	return 0;
>  }
>  
> +static int ast_framebuffer_dirtyfb(struct drm_framebuffer *fb,
> +				   struct drm_file *file_priv,
> +				   unsigned int flags,
> +				   unsigned int color,
> +				   struct drm_clip_rect *clips,
> +				   unsigned int num_clips)
> +{
> +	/* empty placeholder function to enable fbcon shadow buffer */
> +	return 0;
> +}
> +
> +static const struct drm_framebuffer_funcs ast_framebuffer_funcs = {
> +	.destroy	= drm_gem_fb_destroy,
> +	.create_handle	= drm_gem_fb_create_handle,
> +	.dirty		= ast_framebuffer_dirtyfb,
> +};
> +
> +static struct drm_framebuffer *
> +ast_mode_config_fb_create(struct drm_device *dev, struct drm_file *file,
> +			  const struct drm_mode_fb_cmd2 *mode_cmd)
> +{
> +	return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
> +					    &ast_framebuffer_funcs);
> +}
> +
>  static const struct drm_mode_config_funcs ast_mode_funcs = {
> -	.fb_create = drm_gem_fb_create
> +	.fb_create = ast_mode_config_fb_create
>  };
>  
>  static u32 ast_get_vram_info(struct drm_device *dev)
> @@ -502,7 +527,7 @@ int ast_driver_load(struct drm_device *dev, unsigned long flags)
>  	if (ret)
>  		goto out_free;
>  
> -	ret = ast_fbdev_init(dev);
> +	ret = drm_fbdev_generic_setup(dev, 32);
>  	if (ret)
>  		goto out_free;
>  
> @@ -520,7 +545,6 @@ void ast_driver_unload(struct drm_device *dev)
>  	ast_release_firmware(dev);
>  	kfree(ast->dp501_fw_addr);
>  	ast_mode_fini(dev);
> -	ast_fbdev_fini(dev);
>  	drm_mode_config_cleanup(dev);
>  
>  	ast_mm_fini(ast);
> diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
> index c48249df758e..3c0716891b29 100644
> --- a/drivers/gpu/drm/ast/ast_mode.c
> +++ b/drivers/gpu/drm/ast/ast_mode.c
> @@ -525,18 +525,12 @@ static int ast_crtc_do_set_base(struct drm_crtc *crtc,
>  				struct drm_framebuffer *fb,
>  				int x, int y, int atomic)
>  {
> -	struct ast_private *ast = crtc->dev->dev_private;
>  	struct drm_gem_vram_object *gbo;
>  	int ret;
>  	s64 gpu_addr;
> -	void *base;
>  
>  	if (!atomic && fb) {
>  		gbo = drm_gem_vram_of_gem(fb->obj[0]);
> -
> -		/* unmap if console */
> -		if (ast->fbdev->helper.fb == fb)
> -			drm_gem_vram_kunmap(gbo);
>  		drm_gem_vram_unpin(gbo);
>  	}
>  
> @@ -551,17 +545,6 @@ static int ast_crtc_do_set_base(struct drm_crtc *crtc,
>  		goto err_drm_gem_vram_unpin;
>  	}
>  
> -	if (ast->fbdev->helper.fb == crtc->primary->fb) {
> -		/* if pushing console in kmap it */
> -		base = drm_gem_vram_kmap(gbo, true, NULL);
> -		if (IS_ERR(base)) {
> -			ret = PTR_ERR(base);
> -			DRM_ERROR("failed to kmap fbcon\n");
> -		} else {
> -			ast_fbdev_set_base(ast, gpu_addr);
> -		}
> -	}
> -
>  	ast_set_offset_reg(crtc);
>  	ast_set_start_address_crt1(crtc, (u32)gpu_addr);
>  
> @@ -618,14 +601,10 @@ static void ast_crtc_disable(struct drm_crtc *crtc)
>  	DRM_DEBUG_KMS("\n");
>  	ast_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
>  	if (crtc->primary->fb) {
> -		struct ast_private *ast = crtc->dev->dev_private;
>  		struct drm_framebuffer *fb = crtc->primary->fb;
>  		struct drm_gem_vram_object *gbo =
>  			drm_gem_vram_of_gem(fb->obj[0]);
>  
> -		/* unmap if console */
> -		if (ast->fbdev->helper.fb == fb)
> -			drm_gem_vram_kunmap(gbo);
>  		drm_gem_vram_unpin(gbo);
>  	}
>  	crtc->primary->fb = NULL;
> 
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Re: [PATCH 3/5] drm/ast: Replace struct ast_fbdev with generic framebuffer emulation

[Noralf Trønnes]

Den 03.07.2019 10.33, skrev Thomas Zimmermann:
> This patch replaces ast's framebuffer console with DRM's generic
> implememtation. All respective code is being removed from the driver.
> 
> The console is set up with a shadow buffer. The actual buffer object is
> not permanently pinned in video ram, but just another buffer object that
> the driver moves in and out of vram as necessary. The driver's function
> ast_crtc_do_set_base() used to contain special handling for the framebuffer
> console. With the new generic framebuffer, the driver does not need this
> code an longer.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>  drivers/gpu/drm/ast/Makefile   |   2 +-
>  drivers/gpu/drm/ast/ast_drv.c  |  22 ++-
>  drivers/gpu/drm/ast/ast_drv.h  |  17 --
>  drivers/gpu/drm/ast/ast_fb.c   | 341 ---------------------------------
>  drivers/gpu/drm/ast/ast_main.c |  30 ++-
>  drivers/gpu/drm/ast/ast_mode.c |  21 --
>  6 files changed, 41 insertions(+), 392 deletions(-)
>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
> 
> diff --git a/drivers/gpu/drm/ast/Makefile b/drivers/gpu/drm/ast/Makefile
> index b086dae17013..561f7c4199e4 100644
> --- a/drivers/gpu/drm/ast/Makefile
> +++ b/drivers/gpu/drm/ast/Makefile
> @@ -3,6 +3,6 @@
>  # Makefile for the drm device driver.  This driver provides support for the
>  # Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher.
>  
> -ast-y := ast_drv.o ast_main.o ast_mode.o ast_fb.o ast_ttm.o ast_post.o ast_dp501.o
> +ast-y := ast_drv.o ast_main.o ast_mode.o ast_ttm.o ast_post.o ast_dp501.o
>  
>  obj-$(CONFIG_DRM_AST) := ast.o
> diff --git a/drivers/gpu/drm/ast/ast_drv.c b/drivers/gpu/drm/ast/ast_drv.c
> index 3811997e78c4..75f55ac1a218 100644
> --- a/drivers/gpu/drm/ast/ast_drv.c
> +++ b/drivers/gpu/drm/ast/ast_drv.c
> @@ -103,25 +103,29 @@ static int ast_drm_freeze(struct drm_device *dev)
>  
>  	pci_save_state(dev->pdev);
>  
> -	console_lock();
> -	ast_fbdev_set_suspend(dev, 1);
> -	console_unlock();
> +	if (dev->fb_helper) {
> +		console_lock();
> +		drm_fb_helper_set_suspend(dev->fb_helper, 1);
> +		console_unlock();
> +	}

You can call drm_fb_helper_set_suspend_unlocked() unconditionally here
and it will do the NULL check and locking for you.

> +
>  	return 0;
>  }
>  
>  static int ast_drm_thaw(struct drm_device *dev)
>  {
> -	int error = 0;
> -
>  	ast_post_gpu(dev);
>  
>  	drm_mode_config_reset(dev);
>  	drm_helper_resume_force_mode(dev);
>  
> -	console_lock();
> -	ast_fbdev_set_suspend(dev, 0);
> -	console_unlock();
> -	return error;
> +	if (dev->fb_helper) {
> +		console_lock();
> +		drm_fb_helper_set_suspend(dev->fb_helper, 0);
> +		console_unlock();
> +	}

Same here.

With that:

Acked-by: Noralf Trønnes <noralf@tronnes.org>

> +
> +	return 0;
>  }
>  
>  static int ast_drm_resume(struct drm_device *dev)
> diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
> index ca794a3fcf8f..907d7480b7ba 100644
> --- a/drivers/gpu/drm/ast/ast_drv.h
> +++ b/drivers/gpu/drm/ast/ast_drv.h
> @@ -81,8 +81,6 @@ enum ast_tx_chip {
>  #define AST_DRAM_4Gx16   7
>  #define AST_DRAM_8Gx16   8
>  
> -struct ast_fbdev;
> -
>  struct ast_private {
>  	struct drm_device *dev;
>  
> @@ -96,8 +94,6 @@ struct ast_private {
>  	uint32_t mclk;
>  	uint32_t vram_size;
>  
> -	struct ast_fbdev *fbdev;
> -
>  	int fb_mtrr;
>  
>  	struct drm_gem_object *cursor_cache;
> @@ -239,14 +235,6 @@ struct ast_encoder {
>  	struct drm_encoder base;
>  };
>  
> -struct ast_fbdev {
> -	struct drm_fb_helper helper; /* must be first */
> -	void *sysram;
> -	int size;
> -	int x1, y1, x2, y2; /* dirty rect */
> -	spinlock_t dirty_lock;
> -};
> -
>  #define to_ast_crtc(x) container_of(x, struct ast_crtc, base)
>  #define to_ast_connector(x) container_of(x, struct ast_connector, base)
>  #define to_ast_encoder(x) container_of(x, struct ast_encoder, base)
> @@ -289,11 +277,6 @@ struct ast_vbios_mode_info {
>  extern int ast_mode_init(struct drm_device *dev);
>  extern void ast_mode_fini(struct drm_device *dev);
>  
> -int ast_fbdev_init(struct drm_device *dev);
> -void ast_fbdev_fini(struct drm_device *dev);
> -void ast_fbdev_set_suspend(struct drm_device *dev, int state);
> -void ast_fbdev_set_base(struct ast_private *ast, unsigned long gpu_addr);
> -
>  #define AST_MM_ALIGN_SHIFT 4
>  #define AST_MM_ALIGN_MASK ((1 << AST_MM_ALIGN_SHIFT) - 1)
>  
> diff --git a/drivers/gpu/drm/ast/ast_fb.c b/drivers/gpu/drm/ast/ast_fb.c
> deleted file mode 100644
> index a849e58b40bc..000000000000
> --- a/drivers/gpu/drm/ast/ast_fb.c
> +++ /dev/null
> @@ -1,341 +0,0 @@
> -/*
> - * Copyright 2012 Red Hat Inc.
> - *
> - * Permission is hereby granted, free of charge, to any person obtaining a
> - * copy of this software and associated documentation files (the
> - * "Software"), to deal in the Software without restriction, including
> - * without limitation the rights to use, copy, modify, merge, publish,
> - * distribute, sub license, and/or sell copies of the Software, and to
> - * permit persons to whom the Software is furnished to do so, subject to
> - * the following conditions:
> - *
> - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> - * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
> - * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
> - * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
> - * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
> - * USE OR OTHER DEALINGS IN THE SOFTWARE.
> - *
> - * The above copyright notice and this permission notice (including the
> - * next paragraph) shall be included in all copies or substantial portions
> - * of the Software.
> - *
> - */
> -/*
> - * Authors: Dave Airlie <airlied@redhat.com>
> - */
> -#include <linux/module.h>
> -#include <linux/kernel.h>
> -#include <linux/errno.h>
> -#include <linux/string.h>
> -#include <linux/mm.h>
> -#include <linux/tty.h>
> -#include <linux/sysrq.h>
> -#include <linux/delay.h>
> -#include <linux/init.h>
> -
> -
> -#include <drm/drmP.h>
> -#include <drm/drm_crtc.h>
> -#include <drm/drm_crtc_helper.h>
> -#include <drm/drm_fb_helper.h>
> -#include <drm/drm_gem_framebuffer_helper.h>
> -#include <drm/drm_util.h>
> -
> -#include "ast_drv.h"
> -
> -static void ast_dirty_update(struct ast_fbdev *afbdev,
> -			     int x, int y, int width, int height)
> -{
> -	int i;
> -	struct drm_gem_vram_object *gbo;
> -	int src_offset, dst_offset;
> -	int ret;
> -	u8 *dst;
> -	bool unmap = false;
> -	bool store_for_later = false;
> -	int x2, y2;
> -	unsigned long flags;
> -	struct drm_framebuffer *fb = afbdev->helper.fb;
> -	int bpp = fb->format->cpp[0];
> -
> -	gbo = drm_gem_vram_of_gem(fb->obj[0]);
> -
> -	if (drm_can_sleep()) {
> -		/* We pin the BO so it won't be moved during the
> -		 * update. The actual location, video RAM or system
> -		 * memory, is not important.
> -		 */
> -		ret = drm_gem_vram_pin(gbo, 0);
> -		if (ret) {
> -			if (ret != -EBUSY)
> -				return;
> -			store_for_later = true;
> -		}
> -	} else {
> -		store_for_later = true;
> -	}
> -
> -	x2 = x + width - 1;
> -	y2 = y + height - 1;
> -	spin_lock_irqsave(&afbdev->dirty_lock, flags);
> -
> -	if (afbdev->y1 < y)
> -		y = afbdev->y1;
> -	if (afbdev->y2 > y2)
> -		y2 = afbdev->y2;
> -	if (afbdev->x1 < x)
> -		x = afbdev->x1;
> -	if (afbdev->x2 > x2)
> -		x2 = afbdev->x2;
> -
> -	if (store_for_later) {
> -		afbdev->x1 = x;
> -		afbdev->x2 = x2;
> -		afbdev->y1 = y;
> -		afbdev->y2 = y2;
> -		spin_unlock_irqrestore(&afbdev->dirty_lock, flags);
> -		return;
> -	}
> -
> -	afbdev->x1 = afbdev->y1 = INT_MAX;
> -	afbdev->x2 = afbdev->y2 = 0;
> -	spin_unlock_irqrestore(&afbdev->dirty_lock, flags);
> -
> -	dst = drm_gem_vram_kmap(gbo, false, NULL);
> -	if (IS_ERR(dst)) {
> -		DRM_ERROR("failed to kmap fb updates\n");
> -		goto out;
> -	} else if (!dst) {
> -		dst = drm_gem_vram_kmap(gbo, true, NULL);
> -		if (IS_ERR(dst)) {
> -			DRM_ERROR("failed to kmap fb updates\n");
> -			goto out;
> -		}
> -		unmap = true;
> -	}
> -
> -	for (i = y; i <= y2; i++) {
> -		/* assume equal stride for now */
> -		src_offset = dst_offset = i * fb->pitches[0] + (x * bpp);
> -		memcpy_toio(dst + dst_offset, afbdev->sysram + src_offset,
> -			    (x2 - x + 1) * bpp);
> -	}
> -
> -	if (unmap)
> -		drm_gem_vram_kunmap(gbo);
> -
> -out:
> -	drm_gem_vram_unpin(gbo);
> -}
> -
> -static void ast_fillrect(struct fb_info *info,
> -			 const struct fb_fillrect *rect)
> -{
> -	struct ast_fbdev *afbdev = info->par;
> -	drm_fb_helper_sys_fillrect(info, rect);
> -	ast_dirty_update(afbdev, rect->dx, rect->dy, rect->width,
> -			 rect->height);
> -}
> -
> -static void ast_copyarea(struct fb_info *info,
> -			 const struct fb_copyarea *area)
> -{
> -	struct ast_fbdev *afbdev = info->par;
> -	drm_fb_helper_sys_copyarea(info, area);
> -	ast_dirty_update(afbdev, area->dx, area->dy, area->width,
> -			 area->height);
> -}
> -
> -static void ast_imageblit(struct fb_info *info,
> -			  const struct fb_image *image)
> -{
> -	struct ast_fbdev *afbdev = info->par;
> -	drm_fb_helper_sys_imageblit(info, image);
> -	ast_dirty_update(afbdev, image->dx, image->dy, image->width,
> -			 image->height);
> -}
> -
> -static struct fb_ops astfb_ops = {
> -	.owner = THIS_MODULE,
> -	.fb_check_var = drm_fb_helper_check_var,
> -	.fb_set_par = drm_fb_helper_set_par,
> -	.fb_fillrect = ast_fillrect,
> -	.fb_copyarea = ast_copyarea,
> -	.fb_imageblit = ast_imageblit,
> -	.fb_pan_display = drm_fb_helper_pan_display,
> -	.fb_blank = drm_fb_helper_blank,
> -	.fb_setcmap = drm_fb_helper_setcmap,
> -};
> -
> -static int astfb_create_object(struct ast_fbdev *afbdev,
> -			       const struct drm_mode_fb_cmd2 *mode_cmd,
> -			       struct drm_gem_object **gobj_p)
> -{
> -	struct drm_device *dev = afbdev->helper.dev;
> -	u32 size;
> -	struct drm_gem_object *gobj;
> -	int ret = 0;
> -
> -	size = mode_cmd->pitches[0] * mode_cmd->height;
> -	ret = ast_gem_create(dev, size, true, &gobj);
> -	if (ret)
> -		return ret;
> -
> -	*gobj_p = gobj;
> -	return ret;
> -}
> -
> -static int astfb_create(struct drm_fb_helper *helper,
> -			struct drm_fb_helper_surface_size *sizes)
> -{
> -	struct ast_fbdev *afbdev =
> -		container_of(helper, struct ast_fbdev, helper);
> -	struct drm_device *dev = afbdev->helper.dev;
> -	struct drm_mode_fb_cmd2 mode_cmd;
> -	struct drm_framebuffer *fb;
> -	struct fb_info *info;
> -	int size, ret;
> -	void *sysram;
> -	struct drm_gem_object *gobj = NULL;
> -	mode_cmd.width = sizes->surface_width;
> -	mode_cmd.height = sizes->surface_height;
> -	mode_cmd.pitches[0] = mode_cmd.width * ((sizes->surface_bpp + 7)/8);
> -
> -	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
> -							  sizes->surface_depth);
> -
> -	size = mode_cmd.pitches[0] * mode_cmd.height;
> -
> -	ret = astfb_create_object(afbdev, &mode_cmd, &gobj);
> -	if (ret) {
> -		DRM_ERROR("failed to create fbcon backing object %d\n", ret);
> -		return ret;
> -	}
> -
> -	sysram = vmalloc(size);
> -	if (!sysram)
> -		return -ENOMEM;
> -
> -	info = drm_fb_helper_alloc_fbi(helper);
> -	if (IS_ERR(info)) {
> -		ret = PTR_ERR(info);
> -		goto out;
> -	}
> -	fb = drm_gem_fbdev_fb_create(dev, sizes, 0, gobj, NULL);
> -	if (IS_ERR(fb)) {
> -		ret = PTR_ERR(fb);
> -		goto out;
> -	}
> -
> -	afbdev->sysram = sysram;
> -	afbdev->size = size;
> -
> -	afbdev->helper.fb = fb;
> -
> -	info->fbops = &astfb_ops;
> -
> -	info->apertures->ranges[0].base = pci_resource_start(dev->pdev, 0);
> -	info->apertures->ranges[0].size = pci_resource_len(dev->pdev, 0);
> -
> -	drm_fb_helper_fill_info(info, &afbdev->helper, sizes);
> -
> -	info->screen_base = sysram;
> -	info->screen_size = size;
> -
> -	info->pixmap.flags = FB_PIXMAP_SYSTEM;
> -
> -	DRM_DEBUG_KMS("allocated %dx%d\n",
> -		      fb->width, fb->height);
> -
> -	return 0;
> -
> -out:
> -	vfree(sysram);
> -	return ret;
> -}
> -
> -static const struct drm_fb_helper_funcs ast_fb_helper_funcs = {
> -	.fb_probe = astfb_create,
> -};
> -
> -static void ast_fbdev_destroy(struct drm_device *dev,
> -			      struct ast_fbdev *afbdev)
> -{
> -	drm_helper_force_disable_all(dev);
> -	drm_fb_helper_unregister_fbi(&afbdev->helper);
> -
> -	drm_fb_helper_fini(&afbdev->helper);
> -	drm_framebuffer_put(afbdev->helper.fb);
> -
> -	vfree(afbdev->sysram);
> -}
> -
> -int ast_fbdev_init(struct drm_device *dev)
> -{
> -	struct ast_private *ast = dev->dev_private;
> -	struct ast_fbdev *afbdev;
> -	int ret;
> -
> -	afbdev = kzalloc(sizeof(struct ast_fbdev), GFP_KERNEL);
> -	if (!afbdev)
> -		return -ENOMEM;
> -
> -	ast->fbdev = afbdev;
> -	spin_lock_init(&afbdev->dirty_lock);
> -
> -	drm_fb_helper_prepare(dev, &afbdev->helper, &ast_fb_helper_funcs);
> -
> -	ret = drm_fb_helper_init(dev, &afbdev->helper, 1);
> -	if (ret)
> -		goto free;
> -
> -	ret = drm_fb_helper_single_add_all_connectors(&afbdev->helper);
> -	if (ret)
> -		goto fini;
> -
> -	/* disable all the possible outputs/crtcs before entering KMS mode */
> -	drm_helper_disable_unused_functions(dev);
> -
> -	ret = drm_fb_helper_initial_config(&afbdev->helper, 32);
> -	if (ret)
> -		goto fini;
> -
> -	return 0;
> -
> -fini:
> -	drm_fb_helper_fini(&afbdev->helper);
> -free:
> -	kfree(afbdev);
> -	return ret;
> -}
> -
> -void ast_fbdev_fini(struct drm_device *dev)
> -{
> -	struct ast_private *ast = dev->dev_private;
> -
> -	if (!ast->fbdev)
> -		return;
> -
> -	ast_fbdev_destroy(dev, ast->fbdev);
> -	kfree(ast->fbdev);
> -	ast->fbdev = NULL;
> -}
> -
> -void ast_fbdev_set_suspend(struct drm_device *dev, int state)
> -{
> -	struct ast_private *ast = dev->dev_private;
> -
> -	if (!ast->fbdev)
> -		return;
> -
> -	drm_fb_helper_set_suspend(&ast->fbdev->helper, state);
> -}
> -
> -void ast_fbdev_set_base(struct ast_private *ast, unsigned long gpu_addr)
> -{
> -	ast->fbdev->helper.fbdev->fix.smem_start =
> -		ast->fbdev->helper.fbdev->apertures->ranges[0].base + gpu_addr;
> -	ast->fbdev->helper.fbdev->fix.smem_len = ast->vram_size - gpu_addr;
> -}
> diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
> index 1bd61696e509..78e8e20ff577 100644
> --- a/drivers/gpu/drm/ast/ast_main.c
> +++ b/drivers/gpu/drm/ast/ast_main.c
> @@ -383,8 +383,33 @@ static int ast_get_dram_info(struct drm_device *dev)
>  	return 0;
>  }
>  
> +static int ast_framebuffer_dirtyfb(struct drm_framebuffer *fb,
> +				   struct drm_file *file_priv,
> +				   unsigned int flags,
> +				   unsigned int color,
> +				   struct drm_clip_rect *clips,
> +				   unsigned int num_clips)
> +{
> +	/* empty placeholder function to enable fbcon shadow buffer */
> +	return 0;
> +}
> +
> +static const struct drm_framebuffer_funcs ast_framebuffer_funcs = {
> +	.destroy	= drm_gem_fb_destroy,
> +	.create_handle	= drm_gem_fb_create_handle,
> +	.dirty		= ast_framebuffer_dirtyfb,
> +};
> +
> +static struct drm_framebuffer *
> +ast_mode_config_fb_create(struct drm_device *dev, struct drm_file *file,
> +			  const struct drm_mode_fb_cmd2 *mode_cmd)
> +{
> +	return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
> +					    &ast_framebuffer_funcs);
> +}
> +
>  static const struct drm_mode_config_funcs ast_mode_funcs = {
> -	.fb_create = drm_gem_fb_create
> +	.fb_create = ast_mode_config_fb_create
>  };
>  
>  static u32 ast_get_vram_info(struct drm_device *dev)
> @@ -502,7 +527,7 @@ int ast_driver_load(struct drm_device *dev, unsigned long flags)
>  	if (ret)
>  		goto out_free;
>  
> -	ret = ast_fbdev_init(dev);
> +	ret = drm_fbdev_generic_setup(dev, 32);
>  	if (ret)
>  		goto out_free;
>  
> @@ -520,7 +545,6 @@ void ast_driver_unload(struct drm_device *dev)
>  	ast_release_firmware(dev);
>  	kfree(ast->dp501_fw_addr);
>  	ast_mode_fini(dev);
> -	ast_fbdev_fini(dev);
>  	drm_mode_config_cleanup(dev);
>  
>  	ast_mm_fini(ast);
> diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
> index c48249df758e..3c0716891b29 100644
> --- a/drivers/gpu/drm/ast/ast_mode.c
> +++ b/drivers/gpu/drm/ast/ast_mode.c
> @@ -525,18 +525,12 @@ static int ast_crtc_do_set_base(struct drm_crtc *crtc,
>  				struct drm_framebuffer *fb,
>  				int x, int y, int atomic)
>  {
> -	struct ast_private *ast = crtc->dev->dev_private;
>  	struct drm_gem_vram_object *gbo;
>  	int ret;
>  	s64 gpu_addr;
> -	void *base;
>  
>  	if (!atomic && fb) {
>  		gbo = drm_gem_vram_of_gem(fb->obj[0]);
> -
> -		/* unmap if console */
> -		if (ast->fbdev->helper.fb == fb)
> -			drm_gem_vram_kunmap(gbo);
>  		drm_gem_vram_unpin(gbo);
>  	}
>  
> @@ -551,17 +545,6 @@ static int ast_crtc_do_set_base(struct drm_crtc *crtc,
>  		goto err_drm_gem_vram_unpin;
>  	}
>  
> -	if (ast->fbdev->helper.fb == crtc->primary->fb) {
> -		/* if pushing console in kmap it */
> -		base = drm_gem_vram_kmap(gbo, true, NULL);
> -		if (IS_ERR(base)) {
> -			ret = PTR_ERR(base);
> -			DRM_ERROR("failed to kmap fbcon\n");
> -		} else {
> -			ast_fbdev_set_base(ast, gpu_addr);
> -		}
> -	}
> -
>  	ast_set_offset_reg(crtc);
>  	ast_set_start_address_crt1(crtc, (u32)gpu_addr);
>  
> @@ -618,14 +601,10 @@ static void ast_crtc_disable(struct drm_crtc *crtc)
>  	DRM_DEBUG_KMS("\n");
>  	ast_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
>  	if (crtc->primary->fb) {
> -		struct ast_private *ast = crtc->dev->dev_private;
>  		struct drm_framebuffer *fb = crtc->primary->fb;
>  		struct drm_gem_vram_object *gbo =
>  			drm_gem_vram_of_gem(fb->obj[0]);
>  
> -		/* unmap if console */
> -		if (ast->fbdev->helper.fb == fb)
> -			drm_gem_vram_kunmap(gbo);
>  		drm_gem_vram_unpin(gbo);
>  	}
>  	crtc->primary->fb = NULL;
> 
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Re: [PATCH 4/5] drm/bochs: Use shadow buffer for bochs framebuffer console

[Noralf Trønnes]

Den 03.07.2019 10.33, skrev Thomas Zimmermann:
> The bochs driver (and virtual hardware) requires buffer objects to
> reside in video ram to display them to the screen. So it can not
> display the framebuffer console because the respective buffer object
> is permanently pinned in system memory.
> 
> Using a shadow buffer for the console solves this problem. The console
> emulation will pin the buffer object only during updates from the shadow
> buffer. Otherwise, the bochs driver can freely relocated the buffer
> between system memory and video ram.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---

Acked-by: Noralf Trønnes <noralf@tronnes.org>
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Re: [PATCH 4/5] drm/bochs: Use shadow buffer for bochs framebuffer console

[Noralf Trønnes]

Den 03.07.2019 10.33, skrev Thomas Zimmermann:
> The bochs driver (and virtual hardware) requires buffer objects to
> reside in video ram to display them to the screen. So it can not
> display the framebuffer console because the respective buffer object
> is permanently pinned in system memory.
> 
> Using a shadow buffer for the console solves this problem. The console
> emulation will pin the buffer object only during updates from the shadow
> buffer. Otherwise, the bochs driver can freely relocated the buffer
> between system memory and video ram.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---

Acked-by: Noralf Trønnes <noralf@tronnes.org>
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Re: [PATCH 5/5] drm/mgag200: Replace struct mga_fbdev with generic framebuffer emulation

[Noralf Trønnes]

Den 03.07.2019 10.33, skrev Thomas Zimmermann:
> This patch replaces mgag200's framebuffer console with DRM's generic
> implememtation. All respective code is being removed from the driver.
> 
> The console is set up with a shadow buffer. The actual buffer object is
> not permanently pinned in video ram, but just another buffer object that
> the driver moves in and out of vram as necessary. The driver's function
> mga_crtc_do_set_base() used to contain special handling for the framebuffer
> console. With the new generic framebuffer, the driver does not need this
> code an longer.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---

<snip>

> diff --git a/drivers/gpu/drm/mgag200/mgag200_main.c b/drivers/gpu/drm/mgag200/mgag200_main.c
> index b10f7265b5c4..6d943a008752 100644
> --- a/drivers/gpu/drm/mgag200/mgag200_main.c
> +++ b/drivers/gpu/drm/mgag200/mgag200_main.c
> @@ -14,8 +14,33 @@
>  
>  #include "mgag200_drv.h"
>  
> +static int mga_framebuffer_dirtyfb(struct drm_framebuffer *fb,
> +				   struct drm_file *file_priv,
> +				   unsigned int flags,
> +				   unsigned int color,
> +				   struct drm_clip_rect *clips,
> +				   unsigned int num_clips)
> +{
> +	/* empty placeholder function to enable fbcon shadow buffer */
> +	return 0;
> +}
> +
> +static const struct drm_framebuffer_funcs mga_framebuffer_funcs = {
> +	.destroy	= drm_gem_fb_destroy,
> +	.create_handle	= drm_gem_fb_create_handle,
> +	.dirty		= mga_framebuffer_dirtyfb,
> +};
> +
> +static struct drm_framebuffer *
> +mga_mode_config_funcs_fb_create(struct drm_device *dev, struct drm_file *file,
> +				const struct drm_mode_fb_cmd2 *mode_cmd)
> +{
> +	return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
> +					    &mga_framebuffer_funcs);
> +}
> +
>  static const struct drm_mode_config_funcs mga_mode_funcs = {
> -	.fb_create = drm_gem_fb_create
> +	.fb_create = mga_mode_config_funcs_fb_create
>  };
>  
>  static int mga_probe_vram(struct mga_device *mdev, void __iomem *mem)
> @@ -162,7 +187,7 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
>  	if (IS_G200_SE(mdev) && mdev->mc.vram_size < (2048*1024))
>  		dev->mode_config.preferred_depth = 16;
>  	else
> -		dev->mode_config.preferred_depth = 24;
> +		dev->mode_config.preferred_depth = 32;

Please mention this change and the reason for it in the commit message.

>  	dev->mode_config.prefer_shadow = 1;
>  
>  	r = mgag200_modeset_init(mdev);
> @@ -186,6 +211,13 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
>  	}
>  	mdev->cursor.pixels_current = NULL;
>  
> +	r = drm_fbdev_generic_setup(mdev->dev, 0);
> +	if (r) {
> +		dev_err(&dev->pdev->dev,
> +			"drm_fbdev_generic_setup failed: %d\n", r);

drm_fbdev_generic_setup() will print an error message on failure so you
don't need to do it.

Acked-by: Noralf Trønnes <noralf@tronnes.org>

> +		goto err_modeset;
> +	}
> +
>  	return 0;
>  
>  err_modeset:
> @@ -204,32 +236,7 @@ void mgag200_driver_unload(struct drm_device *dev)
>  	if (mdev == NULL)
>  		return;
>  	mgag200_modeset_fini(mdev);
> -	mgag200_fbdev_fini(mdev);
>  	drm_mode_config_cleanup(dev);
>  	mgag200_mm_fini(mdev);
>  	dev->dev_private = NULL;
>  }
> -
> -int mgag200_gem_create(struct drm_device *dev,
> -		   u32 size, bool iskernel,
> -		   struct drm_gem_object **obj)
> -{
> -	struct drm_gem_vram_object *gbo;
> -	int ret;
> -
> -	*obj = NULL;
> -
> -	size = roundup(size, PAGE_SIZE);
> -	if (size == 0)
> -		return -EINVAL;
> -
> -	gbo = drm_gem_vram_create(dev, &dev->vram_mm->bdev, size, 0, false);
> -	if (IS_ERR(gbo)) {
> -		ret = PTR_ERR(gbo);
> -		if (ret != -ERESTARTSYS)
> -			DRM_ERROR("failed to allocate GEM object\n");
> -		return ret;
> -	}
> -	*obj = &gbo->gem;
> -	return 0;
> -}
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Re: [PATCH 5/5] drm/mgag200: Replace struct mga_fbdev with generic framebuffer emulation

[Noralf Trønnes]

Den 03.07.2019 10.33, skrev Thomas Zimmermann:
> This patch replaces mgag200's framebuffer console with DRM's generic
> implememtation. All respective code is being removed from the driver.
> 
> The console is set up with a shadow buffer. The actual buffer object is
> not permanently pinned in video ram, but just another buffer object that
> the driver moves in and out of vram as necessary. The driver's function
> mga_crtc_do_set_base() used to contain special handling for the framebuffer
> console. With the new generic framebuffer, the driver does not need this
> code an longer.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---

<snip>

> diff --git a/drivers/gpu/drm/mgag200/mgag200_main.c b/drivers/gpu/drm/mgag200/mgag200_main.c
> index b10f7265b5c4..6d943a008752 100644
> --- a/drivers/gpu/drm/mgag200/mgag200_main.c
> +++ b/drivers/gpu/drm/mgag200/mgag200_main.c
> @@ -14,8 +14,33 @@
>  
>  #include "mgag200_drv.h"
>  
> +static int mga_framebuffer_dirtyfb(struct drm_framebuffer *fb,
> +				   struct drm_file *file_priv,
> +				   unsigned int flags,
> +				   unsigned int color,
> +				   struct drm_clip_rect *clips,
> +				   unsigned int num_clips)
> +{
> +	/* empty placeholder function to enable fbcon shadow buffer */
> +	return 0;
> +}
> +
> +static const struct drm_framebuffer_funcs mga_framebuffer_funcs = {
> +	.destroy	= drm_gem_fb_destroy,
> +	.create_handle	= drm_gem_fb_create_handle,
> +	.dirty		= mga_framebuffer_dirtyfb,
> +};
> +
> +static struct drm_framebuffer *
> +mga_mode_config_funcs_fb_create(struct drm_device *dev, struct drm_file *file,
> +				const struct drm_mode_fb_cmd2 *mode_cmd)
> +{
> +	return drm_gem_fb_create_with_funcs(dev, file, mode_cmd,
> +					    &mga_framebuffer_funcs);
> +}
> +
>  static const struct drm_mode_config_funcs mga_mode_funcs = {
> -	.fb_create = drm_gem_fb_create
> +	.fb_create = mga_mode_config_funcs_fb_create
>  };
>  
>  static int mga_probe_vram(struct mga_device *mdev, void __iomem *mem)
> @@ -162,7 +187,7 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
>  	if (IS_G200_SE(mdev) && mdev->mc.vram_size < (2048*1024))
>  		dev->mode_config.preferred_depth = 16;
>  	else
> -		dev->mode_config.preferred_depth = 24;
> +		dev->mode_config.preferred_depth = 32;

Please mention this change and the reason for it in the commit message.

>  	dev->mode_config.prefer_shadow = 1;
>  
>  	r = mgag200_modeset_init(mdev);
> @@ -186,6 +211,13 @@ int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
>  	}
>  	mdev->cursor.pixels_current = NULL;
>  
> +	r = drm_fbdev_generic_setup(mdev->dev, 0);
> +	if (r) {
> +		dev_err(&dev->pdev->dev,
> +			"drm_fbdev_generic_setup failed: %d\n", r);

drm_fbdev_generic_setup() will print an error message on failure so you
don't need to do it.

Acked-by: Noralf Trønnes <noralf@tronnes.org>

> +		goto err_modeset;
> +	}
> +
>  	return 0;
>  
>  err_modeset:
> @@ -204,32 +236,7 @@ void mgag200_driver_unload(struct drm_device *dev)
>  	if (mdev == NULL)
>  		return;
>  	mgag200_modeset_fini(mdev);
> -	mgag200_fbdev_fini(mdev);
>  	drm_mode_config_cleanup(dev);
>  	mgag200_mm_fini(mdev);
>  	dev->dev_private = NULL;
>  }
> -
> -int mgag200_gem_create(struct drm_device *dev,
> -		   u32 size, bool iskernel,
> -		   struct drm_gem_object **obj)
> -{
> -	struct drm_gem_vram_object *gbo;
> -	int ret;
> -
> -	*obj = NULL;
> -
> -	size = roundup(size, PAGE_SIZE);
> -	if (size == 0)
> -		return -EINVAL;
> -
> -	gbo = drm_gem_vram_create(dev, &dev->vram_mm->bdev, size, 0, false);
> -	if (IS_ERR(gbo)) {
> -		ret = PTR_ERR(gbo);
> -		if (ret != -ERESTARTSYS)
> -			DRM_ERROR("failed to allocate GEM object\n");
> -		return ret;
> -	}
> -	*obj = &gbo->gem;
> -	return 0;
> -}
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Re: [PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Noralf Trønnes]

Den 03.07.2019 10.32, skrev Thomas Zimmermann:
> DRM client buffers are permanently mapped throughout their lifetime. This
> prevents us from using generic framebuffer emulation for devices with
> small dedicated video memory, such as ast or mgag200. With fb buffers
> permanently mapped, such devices often won't have enougth space left to
> display other content (e.g., X11).
> 
> This patch set introduces unmappable DRM client buffers for framebuffer
> emulation with shadow buffers. While the shadow buffer remains in system
> memory permanently, the respective buffer object will only be mapped briefly
> during updates from the shadow buffer. Hence, the driver can relocate he
> buffer object among memory regions as needed.
> 
> The default behoviour for DRM client buffers is still to be permanently
> mapped.
> 
> The patch set converts ast and mgag200 to generic framebuffer emulation
> and removes a large amount of framebuffer code from these drivers. For
> bochs, a problem was reported where the driver could not display the console
> because it was pinned in system memory. [1] The patch set fixes this bug
> by converting bochs to use the shadow fb.
> 
> The patch set has been tested on ast and mga200 HW.
> 

I've been thinking, this enables dirty tracking in DRM userspace for
these drivers since the dirty callback is now set on all framebuffers.
Is this OK? Should we add a drm_fbdev_generic_shadow_setup() that sets a
flag enabling the shadow buffer instead?

Really nice diffstat by the way :-)

Noralf.

> [1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html
> 
> Thomas Zimmermann (5):
>   drm/client: Support unmapping of DRM client buffers
>   drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
>   drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
>   drm/bochs: Use shadow buffer for bochs framebuffer console
>   drm/mgag200: Replace struct mga_fbdev with generic framebuffer
>     emulation
> 
>  drivers/gpu/drm/ast/Makefile           |   2 +-
>  drivers/gpu/drm/ast/ast_drv.c          |  22 +-
>  drivers/gpu/drm/ast/ast_drv.h          |  17 --
>  drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
>  drivers/gpu/drm/ast/ast_main.c         |  30 ++-
>  drivers/gpu/drm/ast/ast_mode.c         |  21 --
>  drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
>  drivers/gpu/drm/drm_client.c           |  71 ++++-
>  drivers/gpu/drm/drm_fb_helper.c        |  14 +-
>  drivers/gpu/drm/mgag200/Makefile       |   2 +-
>  drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
>  drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
>  drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
>  drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
>  include/drm/drm_client.h               |   3 +
>  15 files changed, 154 insertions(+), 787 deletions(-)
>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
>  delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c
> 
> --
> 2.21.0
> 

Re: [PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Noralf Trønnes]

Den 03.07.2019 10.32, skrev Thomas Zimmermann:
> DRM client buffers are permanently mapped throughout their lifetime. This
> prevents us from using generic framebuffer emulation for devices with
> small dedicated video memory, such as ast or mgag200. With fb buffers
> permanently mapped, such devices often won't have enougth space left to
> display other content (e.g., X11).
> 
> This patch set introduces unmappable DRM client buffers for framebuffer
> emulation with shadow buffers. While the shadow buffer remains in system
> memory permanently, the respective buffer object will only be mapped briefly
> during updates from the shadow buffer. Hence, the driver can relocate he
> buffer object among memory regions as needed.
> 
> The default behoviour for DRM client buffers is still to be permanently
> mapped.
> 
> The patch set converts ast and mgag200 to generic framebuffer emulation
> and removes a large amount of framebuffer code from these drivers. For
> bochs, a problem was reported where the driver could not display the console
> because it was pinned in system memory. [1] The patch set fixes this bug
> by converting bochs to use the shadow fb.
> 
> The patch set has been tested on ast and mga200 HW.
> 

I've been thinking, this enables dirty tracking in DRM userspace for
these drivers since the dirty callback is now set on all framebuffers.
Is this OK? Should we add a drm_fbdev_generic_shadow_setup() that sets a
flag enabling the shadow buffer instead?

Really nice diffstat by the way :-)

Noralf.

> [1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html
> 
> Thomas Zimmermann (5):
>   drm/client: Support unmapping of DRM client buffers
>   drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
>   drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
>   drm/bochs: Use shadow buffer for bochs framebuffer console
>   drm/mgag200: Replace struct mga_fbdev with generic framebuffer
>     emulation
> 
>  drivers/gpu/drm/ast/Makefile           |   2 +-
>  drivers/gpu/drm/ast/ast_drv.c          |  22 +-
>  drivers/gpu/drm/ast/ast_drv.h          |  17 --
>  drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
>  drivers/gpu/drm/ast/ast_main.c         |  30 ++-
>  drivers/gpu/drm/ast/ast_mode.c         |  21 --
>  drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
>  drivers/gpu/drm/drm_client.c           |  71 ++++-
>  drivers/gpu/drm/drm_fb_helper.c        |  14 +-
>  drivers/gpu/drm/mgag200/Makefile       |   2 +-
>  drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
>  drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
>  drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
>  drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
>  include/drm/drm_client.h               |   3 +
>  15 files changed, 154 insertions(+), 787 deletions(-)
>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
>  delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c
> 
> --
> 2.21.0
> 
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Re: [PATCH 1/5] drm/client: Support unmapping of DRM client buffers

[Thomas Zimmermann]

[-- Attachment #1.1.1: Type: text/plain, Size: 5996 bytes --]

Hi

Am 03.07.19 um 16:07 schrieb Noralf Trønnes:
> 
> 
> Den 03.07.2019 10.32, skrev Thomas Zimmermann:
>> DRM clients, such as the fbdev emulation, have their buffer objects
>> mapped by default. Mapping a buffer implicitly prevents its relocation.
>> Hence, the buffer may permanently consume video memory while it's
>> allocated. This is a problem for drivers of low-memory devices, such as
>> ast, mgag200 or older framebuffer hardware, which will then not have
>> enough memory to display other content (e.g., X11).
>>
>> This patch introduces drm_client_buffer_vmap() and _vunmap(). Internal
>> DRM clients can use these functions to unmap and remap buffer objects
>> as needed.
>>
>> There's no reference counting for vmap operations. Callers are expected
>> to either keep buffers mapped (as it is now), or call vmap and vunmap
>> in pairs around code that accesses the mapped memory.
>>
>> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
>> ---
>>  drivers/gpu/drm/drm_client.c | 71 +++++++++++++++++++++++++++++++-----
>>  include/drm/drm_client.h     |  3 ++
>>  2 files changed, 64 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
>> index 410572f14257..d04660c4470a 100644
>> --- a/drivers/gpu/drm/drm_client.c
>> +++ b/drivers/gpu/drm/drm_client.c
>> @@ -235,7 +235,8 @@ static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
>>  {
>>  	struct drm_device *dev = buffer->client->dev;
>>  
>> -	drm_gem_vunmap(buffer->gem, buffer->vaddr);
>> +	if (buffer->vaddr)
> 
> No need for this, drm_gem_vunmap() has a NULL check.
> 
>> +		drm_gem_vunmap(buffer->gem, buffer->vaddr);
>>  
>>  	if (buffer->gem)
>>  		drm_gem_object_put_unlocked(buffer->gem);
>> @@ -281,6 +282,43 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
>>  
>>  	buffer->gem = obj;
>>  
>> +	vaddr = drm_client_buffer_vmap(buffer);
> 
> I think we should change this and _not_ vmap on buffer creation.
> Eventually we'll get bootsplash and console clients and they will also
> have to deal with these low memory devices. AFAICS the only client that
> will need a virtual address at all times is the fbdev client when it
> doesn't use a shadow buffer.

Exactly my thoughts. I didn't want to overload the patch set with
changing clients to not map the buffer by default. But since you mention
it...

Best regards
Thomas

> 
>> +	if (IS_ERR(vaddr)) {
>> +		ret = PTR_ERR(vaddr);
>> +		goto err_delete;
>> +	}
>> +
>> +	return buffer;
>> +
>> +err_delete:
>> +	drm_client_buffer_delete(buffer);
>> +
>> +	return ERR_PTR(ret);
>> +}
>> +
>> +/**
>> + * drm_client_buffer_vmap - Map DRM client buffer into address space
>> + * @buffer: DRM client buffer
>> + *
>> + * This function maps a client buffer into kernel address space. If the
>> + * buffer is already mapped, it returns the mapping's address.
>> + *
>> + * Client buffer mappings are not ref'counted. Each call to
>> + * drm_client_buffer_vmap() should be followed by a call to
>> + * drm_client_buffer_vunmap(); or the client buffer should be mapped
>> + * throughout its lifetime. The latter is the default.
>> + *
>> + * Returns:
>> + *	The mapped memory's address
>> + */
>> +void *
>> +drm_client_buffer_vmap(struct drm_client_buffer *buffer)
>> +{
>> +	void *vaddr;
>> +
>> +	if (buffer->vaddr)
>> +		return buffer->vaddr;
>> +
>>  	/*
>>  	 * FIXME: The dependency on GEM here isn't required, we could
>>  	 * convert the driver handle to a dma-buf instead and use the
>> @@ -289,21 +327,34 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
>>  	 * fd_install step out of the driver backend hooks, to make that
>>  	 * final step optional for internal users.
>>  	 */
>> -	vaddr = drm_gem_vmap(obj);
>> -	if (IS_ERR(vaddr)) {
>> -		ret = PTR_ERR(vaddr);
>> -		goto err_delete;
>> -	}
>> +	vaddr = drm_gem_vmap(buffer->gem);
>> +	if (IS_ERR(vaddr))
>> +		return vaddr;
>>  
>>  	buffer->vaddr = vaddr;
>>  
>> -	return buffer;
>> +	return vaddr;
>> +}
>> +EXPORT_SYMBOL(drm_client_buffer_vmap);
>>  
>> -err_delete:
>> -	drm_client_buffer_delete(buffer);
>> +/**
>> + * drm_client_buffer_vunmap - Unmap DRM client buffer
>> + * @buffer: DRM client buffer
>> + *
>> + * This function removes a client buffer's memory mmapping. This
>> + * function is only required by clients that manage their buffers
>> + * by themselves. By default, DRM client buffers are mapped throughout
>> + * their entire lifetime.
>> + */
>> +void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
>> +{
>> +	if (!buffer->vaddr)
> 
> No need for a NULL check here either.
> 
> Noralf.
> 
>> +		return;
>>  
>> -	return ERR_PTR(ret);
>> +	drm_gem_vunmap(buffer->gem, buffer->vaddr);
>> +	buffer->vaddr = NULL;
>>  }
>> +EXPORT_SYMBOL(drm_client_buffer_vunmap);
>>  
>>  static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
>>  {
>> diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
>> index 72d51d1e9dd9..e1db1d9da0bf 100644
>> --- a/include/drm/drm_client.h
>> +++ b/include/drm/drm_client.h
>> @@ -149,6 +149,9 @@ struct drm_client_buffer {
>>  struct drm_client_buffer *
>>  drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format);
>>  void drm_client_framebuffer_delete(struct drm_client_buffer *buffer);
>> +void *
>> +drm_client_buffer_vmap(struct drm_client_buffer *buffer);
>> +void drm_client_buffer_vunmap(struct drm_client_buffer *buffer);
>>  
>>  int drm_client_modeset_create(struct drm_client_dev *client);
>>  void drm_client_modeset_free(struct drm_client_dev *client);
>>

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)


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Re: [PATCH 1/5] drm/client: Support unmapping of DRM client buffers

[Thomas Zimmermann]

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Hi

Am 03.07.19 um 16:07 schrieb Noralf Trønnes:
> 
> 
> Den 03.07.2019 10.32, skrev Thomas Zimmermann:
>> DRM clients, such as the fbdev emulation, have their buffer objects
>> mapped by default. Mapping a buffer implicitly prevents its relocation.
>> Hence, the buffer may permanently consume video memory while it's
>> allocated. This is a problem for drivers of low-memory devices, such as
>> ast, mgag200 or older framebuffer hardware, which will then not have
>> enough memory to display other content (e.g., X11).
>>
>> This patch introduces drm_client_buffer_vmap() and _vunmap(). Internal
>> DRM clients can use these functions to unmap and remap buffer objects
>> as needed.
>>
>> There's no reference counting for vmap operations. Callers are expected
>> to either keep buffers mapped (as it is now), or call vmap and vunmap
>> in pairs around code that accesses the mapped memory.
>>
>> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
>> ---
>>  drivers/gpu/drm/drm_client.c | 71 +++++++++++++++++++++++++++++++-----
>>  include/drm/drm_client.h     |  3 ++
>>  2 files changed, 64 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
>> index 410572f14257..d04660c4470a 100644
>> --- a/drivers/gpu/drm/drm_client.c
>> +++ b/drivers/gpu/drm/drm_client.c
>> @@ -235,7 +235,8 @@ static void drm_client_buffer_delete(struct drm_client_buffer *buffer)
>>  {
>>  	struct drm_device *dev = buffer->client->dev;
>>  
>> -	drm_gem_vunmap(buffer->gem, buffer->vaddr);
>> +	if (buffer->vaddr)
> 
> No need for this, drm_gem_vunmap() has a NULL check.
> 
>> +		drm_gem_vunmap(buffer->gem, buffer->vaddr);
>>  
>>  	if (buffer->gem)
>>  		drm_gem_object_put_unlocked(buffer->gem);
>> @@ -281,6 +282,43 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
>>  
>>  	buffer->gem = obj;
>>  
>> +	vaddr = drm_client_buffer_vmap(buffer);
> 
> I think we should change this and _not_ vmap on buffer creation.
> Eventually we'll get bootsplash and console clients and they will also
> have to deal with these low memory devices. AFAICS the only client that
> will need a virtual address at all times is the fbdev client when it
> doesn't use a shadow buffer.

Exactly my thoughts. I didn't want to overload the patch set with
changing clients to not map the buffer by default. But since you mention
it...

Best regards
Thomas

> 
>> +	if (IS_ERR(vaddr)) {
>> +		ret = PTR_ERR(vaddr);
>> +		goto err_delete;
>> +	}
>> +
>> +	return buffer;
>> +
>> +err_delete:
>> +	drm_client_buffer_delete(buffer);
>> +
>> +	return ERR_PTR(ret);
>> +}
>> +
>> +/**
>> + * drm_client_buffer_vmap - Map DRM client buffer into address space
>> + * @buffer: DRM client buffer
>> + *
>> + * This function maps a client buffer into kernel address space. If the
>> + * buffer is already mapped, it returns the mapping's address.
>> + *
>> + * Client buffer mappings are not ref'counted. Each call to
>> + * drm_client_buffer_vmap() should be followed by a call to
>> + * drm_client_buffer_vunmap(); or the client buffer should be mapped
>> + * throughout its lifetime. The latter is the default.
>> + *
>> + * Returns:
>> + *	The mapped memory's address
>> + */
>> +void *
>> +drm_client_buffer_vmap(struct drm_client_buffer *buffer)
>> +{
>> +	void *vaddr;
>> +
>> +	if (buffer->vaddr)
>> +		return buffer->vaddr;
>> +
>>  	/*
>>  	 * FIXME: The dependency on GEM here isn't required, we could
>>  	 * convert the driver handle to a dma-buf instead and use the
>> @@ -289,21 +327,34 @@ drm_client_buffer_create(struct drm_client_dev *client, u32 width, u32 height, u
>>  	 * fd_install step out of the driver backend hooks, to make that
>>  	 * final step optional for internal users.
>>  	 */
>> -	vaddr = drm_gem_vmap(obj);
>> -	if (IS_ERR(vaddr)) {
>> -		ret = PTR_ERR(vaddr);
>> -		goto err_delete;
>> -	}
>> +	vaddr = drm_gem_vmap(buffer->gem);
>> +	if (IS_ERR(vaddr))
>> +		return vaddr;
>>  
>>  	buffer->vaddr = vaddr;
>>  
>> -	return buffer;
>> +	return vaddr;
>> +}
>> +EXPORT_SYMBOL(drm_client_buffer_vmap);
>>  
>> -err_delete:
>> -	drm_client_buffer_delete(buffer);
>> +/**
>> + * drm_client_buffer_vunmap - Unmap DRM client buffer
>> + * @buffer: DRM client buffer
>> + *
>> + * This function removes a client buffer's memory mmapping. This
>> + * function is only required by clients that manage their buffers
>> + * by themselves. By default, DRM client buffers are mapped throughout
>> + * their entire lifetime.
>> + */
>> +void drm_client_buffer_vunmap(struct drm_client_buffer *buffer)
>> +{
>> +	if (!buffer->vaddr)
> 
> No need for a NULL check here either.
> 
> Noralf.
> 
>> +		return;
>>  
>> -	return ERR_PTR(ret);
>> +	drm_gem_vunmap(buffer->gem, buffer->vaddr);
>> +	buffer->vaddr = NULL;
>>  }
>> +EXPORT_SYMBOL(drm_client_buffer_vunmap);
>>  
>>  static void drm_client_buffer_rmfb(struct drm_client_buffer *buffer)
>>  {
>> diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
>> index 72d51d1e9dd9..e1db1d9da0bf 100644
>> --- a/include/drm/drm_client.h
>> +++ b/include/drm/drm_client.h
>> @@ -149,6 +149,9 @@ struct drm_client_buffer {
>>  struct drm_client_buffer *
>>  drm_client_framebuffer_create(struct drm_client_dev *client, u32 width, u32 height, u32 format);
>>  void drm_client_framebuffer_delete(struct drm_client_buffer *buffer);
>> +void *
>> +drm_client_buffer_vmap(struct drm_client_buffer *buffer);
>> +void drm_client_buffer_vunmap(struct drm_client_buffer *buffer);
>>  
>>  int drm_client_modeset_create(struct drm_client_dev *client);
>>  void drm_client_modeset_free(struct drm_client_dev *client);
>>

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)


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Re: [PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Thomas Zimmermann]

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Hi

Am 03.07.19 um 21:27 schrieb Noralf Trønnes:
> 
> 
> Den 03.07.2019 10.32, skrev Thomas Zimmermann:
>> DRM client buffers are permanently mapped throughout their lifetime. This
>> prevents us from using generic framebuffer emulation for devices with
>> small dedicated video memory, such as ast or mgag200. With fb buffers
>> permanently mapped, such devices often won't have enougth space left to
>> display other content (e.g., X11).
>>
>> This patch set introduces unmappable DRM client buffers for framebuffer
>> emulation with shadow buffers. While the shadow buffer remains in system
>> memory permanently, the respective buffer object will only be mapped briefly
>> during updates from the shadow buffer. Hence, the driver can relocate he
>> buffer object among memory regions as needed.
>>
>> The default behoviour for DRM client buffers is still to be permanently
>> mapped.
>>
>> The patch set converts ast and mgag200 to generic framebuffer emulation
>> and removes a large amount of framebuffer code from these drivers. For
>> bochs, a problem was reported where the driver could not display the console
>> because it was pinned in system memory. [1] The patch set fixes this bug
>> by converting bochs to use the shadow fb.
>>
>> The patch set has been tested on ast and mga200 HW.
>>
> 
> I've been thinking, this enables dirty tracking in DRM userspace for
> these drivers since the dirty callback is now set on all framebuffers.
> Is this OK? Should we add a drm_fbdev_generic_shadow_setup() that sets a
> flag enabling the shadow buffer instead?

Fbdev emulation is special wrt framebuffer setup and there's no way to
distinguish a regular FB from the fbdev's FB. I've been trying
drm_fbdev_generic_shadow_setup(), but ended up duplicating
functionality. The problem was that we cannot get state-flag arguments
into drm_fb_helper_generic_probe().

There already is struct mode_config.prefer_shadow. It signals shadow FB
rendering to userspace. The easiest solution is to add
prefer_shadow_fbdev as well. If either flag is true, fbdev emulation
would enable shadow buffering.

I'm not sure if we should check for the dirty() callback at all.

Best regards
Thomas

> Really nice diffstat by the way :-)
> 
> Noralf.
> 
>> [1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html
>>
>> Thomas Zimmermann (5):
>>   drm/client: Support unmapping of DRM client buffers
>>   drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
>>   drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
>>   drm/bochs: Use shadow buffer for bochs framebuffer console
>>   drm/mgag200: Replace struct mga_fbdev with generic framebuffer
>>     emulation
>>
>>  drivers/gpu/drm/ast/Makefile           |   2 +-
>>  drivers/gpu/drm/ast/ast_drv.c          |  22 +-
>>  drivers/gpu/drm/ast/ast_drv.h          |  17 --
>>  drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
>>  drivers/gpu/drm/ast/ast_main.c         |  30 ++-
>>  drivers/gpu/drm/ast/ast_mode.c         |  21 --
>>  drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
>>  drivers/gpu/drm/drm_client.c           |  71 ++++-
>>  drivers/gpu/drm/drm_fb_helper.c        |  14 +-
>>  drivers/gpu/drm/mgag200/Makefile       |   2 +-
>>  drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
>>  drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
>>  drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
>>  drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
>>  include/drm/drm_client.h               |   3 +
>>  15 files changed, 154 insertions(+), 787 deletions(-)
>>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
>>  delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c
>>
>> --
>> 2.21.0
>>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)


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Re: [PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Thomas Zimmermann]

[-- Attachment #1.1.1: Type: text/plain, Size: 4174 bytes --]

Hi

Am 03.07.19 um 21:27 schrieb Noralf Trønnes:
> 
> 
> Den 03.07.2019 10.32, skrev Thomas Zimmermann:
>> DRM client buffers are permanently mapped throughout their lifetime. This
>> prevents us from using generic framebuffer emulation for devices with
>> small dedicated video memory, such as ast or mgag200. With fb buffers
>> permanently mapped, such devices often won't have enougth space left to
>> display other content (e.g., X11).
>>
>> This patch set introduces unmappable DRM client buffers for framebuffer
>> emulation with shadow buffers. While the shadow buffer remains in system
>> memory permanently, the respective buffer object will only be mapped briefly
>> during updates from the shadow buffer. Hence, the driver can relocate he
>> buffer object among memory regions as needed.
>>
>> The default behoviour for DRM client buffers is still to be permanently
>> mapped.
>>
>> The patch set converts ast and mgag200 to generic framebuffer emulation
>> and removes a large amount of framebuffer code from these drivers. For
>> bochs, a problem was reported where the driver could not display the console
>> because it was pinned in system memory. [1] The patch set fixes this bug
>> by converting bochs to use the shadow fb.
>>
>> The patch set has been tested on ast and mga200 HW.
>>
> 
> I've been thinking, this enables dirty tracking in DRM userspace for
> these drivers since the dirty callback is now set on all framebuffers.
> Is this OK? Should we add a drm_fbdev_generic_shadow_setup() that sets a
> flag enabling the shadow buffer instead?

Fbdev emulation is special wrt framebuffer setup and there's no way to
distinguish a regular FB from the fbdev's FB. I've been trying
drm_fbdev_generic_shadow_setup(), but ended up duplicating
functionality. The problem was that we cannot get state-flag arguments
into drm_fb_helper_generic_probe().

There already is struct mode_config.prefer_shadow. It signals shadow FB
rendering to userspace. The easiest solution is to add
prefer_shadow_fbdev as well. If either flag is true, fbdev emulation
would enable shadow buffering.

I'm not sure if we should check for the dirty() callback at all.

Best regards
Thomas

> Really nice diffstat by the way :-)
> 
> Noralf.
> 
>> [1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html
>>
>> Thomas Zimmermann (5):
>>   drm/client: Support unmapping of DRM client buffers
>>   drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
>>   drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
>>   drm/bochs: Use shadow buffer for bochs framebuffer console
>>   drm/mgag200: Replace struct mga_fbdev with generic framebuffer
>>     emulation
>>
>>  drivers/gpu/drm/ast/Makefile           |   2 +-
>>  drivers/gpu/drm/ast/ast_drv.c          |  22 +-
>>  drivers/gpu/drm/ast/ast_drv.h          |  17 --
>>  drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
>>  drivers/gpu/drm/ast/ast_main.c         |  30 ++-
>>  drivers/gpu/drm/ast/ast_mode.c         |  21 --
>>  drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
>>  drivers/gpu/drm/drm_client.c           |  71 ++++-
>>  drivers/gpu/drm/drm_fb_helper.c        |  14 +-
>>  drivers/gpu/drm/mgag200/Makefile       |   2 +-
>>  drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
>>  drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
>>  drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
>>  drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
>>  include/drm/drm_client.h               |   3 +
>>  15 files changed, 154 insertions(+), 787 deletions(-)
>>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
>>  delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c
>>
>> --
>> 2.21.0
>>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)


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Re: [PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Noralf Trønnes]

Den 04.07.2019 09.43, skrev Thomas Zimmermann:
> Hi
> 
> Am 03.07.19 um 21:27 schrieb Noralf Trønnes:
>>
>>
>> Den 03.07.2019 10.32, skrev Thomas Zimmermann:
>>> DRM client buffers are permanently mapped throughout their lifetime. This
>>> prevents us from using generic framebuffer emulation for devices with
>>> small dedicated video memory, such as ast or mgag200. With fb buffers
>>> permanently mapped, such devices often won't have enougth space left to
>>> display other content (e.g., X11).
>>>
>>> This patch set introduces unmappable DRM client buffers for framebuffer
>>> emulation with shadow buffers. While the shadow buffer remains in system
>>> memory permanently, the respective buffer object will only be mapped briefly
>>> during updates from the shadow buffer. Hence, the driver can relocate he
>>> buffer object among memory regions as needed.
>>>
>>> The default behoviour for DRM client buffers is still to be permanently
>>> mapped.
>>>
>>> The patch set converts ast and mgag200 to generic framebuffer emulation
>>> and removes a large amount of framebuffer code from these drivers. For
>>> bochs, a problem was reported where the driver could not display the console
>>> because it was pinned in system memory. [1] The patch set fixes this bug
>>> by converting bochs to use the shadow fb.
>>>
>>> The patch set has been tested on ast and mga200 HW.
>>>
>>
>> I've been thinking, this enables dirty tracking in DRM userspace for
>> these drivers since the dirty callback is now set on all framebuffers.
>> Is this OK? Should we add a drm_fbdev_generic_shadow_setup() that sets a
>> flag enabling the shadow buffer instead?
> 
> Fbdev emulation is special wrt framebuffer setup and there's no way to
> distinguish a regular FB from the fbdev's FB. I've been trying
> drm_fbdev_generic_shadow_setup(), but ended up duplicating
> functionality. The problem was that we cannot get state-flag arguments
> into drm_fb_helper_generic_probe().
> 
> There already is struct mode_config.prefer_shadow. It signals shadow FB
> rendering to userspace. The easiest solution is to add
> prefer_shadow_fbdev as well. If either flag is true, fbdev emulation
> would enable shadow buffering.

How about something like this:

diff --git a/drivers/gpu/drm/drm_fb_helper.c
b/drivers/gpu/drm/drm_fb_helper.c
index 1984e5c54d58..723fe56aa5f5 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -415,7 +415,8 @@ static void drm_fb_helper_dirty_work(struct
work_struct *work)
 		/* Generic fbdev uses a shadow buffer */
 		if (helper->buffer)
 			drm_fb_helper_dirty_blit_real(helper, &clip_copy);
-		helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
+		if (helper->fb->funcs->dirty)
+			helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
 	}
 }

@@ -2209,7 +2210,7 @@ int drm_fb_helper_generic_probe(struct
drm_fb_helper *fb_helper,
 #endif
 	drm_fb_helper_fill_info(fbi, fb_helper, sizes);

-	if (fb->funcs->dirty) {
+	if (fb->funcs->dirty || fb_helper->use_shadow) {
 		struct fb_ops *fbops;
 		void *shadow;

@@ -2310,6 +2311,44 @@ static const struct drm_client_funcs
drm_fbdev_client_funcs = {
 	.hotplug	= drm_fbdev_client_hotplug,
 };

+static int _drm_fbdev_generic_setup(struct drm_device *dev, unsigned
int preferred_bpp, bool use_shadow)
+{
+	struct drm_fb_helper *fb_helper;
+	int ret;
+
+	WARN(dev->fb_helper, "fb_helper is already set!\n");
+
+	if (!drm_fbdev_emulation)
+		return 0;
+
+	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
+	if (!fb_helper)
+		return -ENOMEM;
+
+	ret = drm_client_init(dev, &fb_helper->client, "fbdev",
&drm_fbdev_client_funcs);
+	if (ret) {
+		kfree(fb_helper);
+		DRM_DEV_ERROR(dev->dev, "Failed to register client: %d\n", ret);
+		return ret;
+	}
+
+	if (!preferred_bpp)
+		preferred_bpp = dev->mode_config.preferred_depth;
+	if (!preferred_bpp)
+		preferred_bpp = 32;
+	fb_helper->preferred_bpp = preferred_bpp;
+
+	fb_helper->use_shadow = use_shadow;
+
+	ret = drm_fbdev_client_hotplug(&fb_helper->client);
+	if (ret)
+		DRM_DEV_DEBUG(dev->dev, "client hotplug ret=%d\n", ret);
+
+	drm_client_register(&fb_helper->client);
+
+	return 0;
+}
+
 /**
  * drm_fbdev_generic_setup() - Setup generic fbdev emulation
  * @dev: DRM device
@@ -2338,38 +2377,13 @@ static const struct drm_client_funcs
drm_fbdev_client_funcs = {
  */
 int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int
preferred_bpp)
 {
-	struct drm_fb_helper *fb_helper;
-	int ret;
+	return _drm_fbdev_generic_setup(dev, preferred_bpp, false);
+}
+EXPORT_SYMBOL(drm_fbdev_generic_setup);

-	WARN(dev->fb_helper, "fb_helper is already set!\n");
-
-	if (!drm_fbdev_emulation)
-		return 0;
-
-	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
-	if (!fb_helper)
-		return -ENOMEM;
-
-	ret = drm_client_init(dev, &fb_helper->client, "fbdev",
&drm_fbdev_client_funcs);
-	if (ret) {
-		kfree(fb_helper);
-		DRM_DEV_ERROR(dev->dev, "Failed to register client: %d\n", ret);
-		return ret;
-	}
-
-	if (!preferred_bpp)
-		preferred_bpp = dev->mode_config.preferred_depth;
-	if (!preferred_bpp)
-		preferred_bpp = 32;
-	fb_helper->preferred_bpp = preferred_bpp;
-
-	ret = drm_fbdev_client_hotplug(&fb_helper->client);
-	if (ret)
-		DRM_DEV_DEBUG(dev->dev, "client hotplug ret=%d\n", ret);
-
-	drm_client_register(&fb_helper->client);
-
-	return 0;
+int drm_fbdev_generic_shadow_setup(struct drm_device *dev, unsigned int
preferred_bpp)
+{
+	return _drm_fbdev_generic_setup(dev, preferred_bpp, true);
 }
 EXPORT_SYMBOL(drm_fbdev_generic_setup);

diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index c8a8ae2a678a..39f063de8cbc 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -186,6 +186,8 @@ struct drm_fb_helper {
 	 * See also: @deferred_setup
 	 */
 	int preferred_bpp;
+
+	bool use_shadow;
 };

 static inline struct drm_fb_helper *


> 
> I'm not sure if we should check for the dirty() callback at all.
> 

Hm, why do you think that?

The thing with fbdev defio is that it only supports kmalloc and vmalloc
allocated memory (page->lru is avail.). This means that only the CMA
drivers can use defio without shadow memory. To keep things simple
everyone with a dirty() callback gets a shadow buffer.

Noralf.

> Best regards
> Thomas
> 
>> Really nice diffstat by the way :-)
>>
>> Noralf.
>>
>>> [1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html
>>>
>>> Thomas Zimmermann (5):
>>>   drm/client: Support unmapping of DRM client buffers
>>>   drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
>>>   drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
>>>   drm/bochs: Use shadow buffer for bochs framebuffer console
>>>   drm/mgag200: Replace struct mga_fbdev with generic framebuffer
>>>     emulation
>>>
>>>  drivers/gpu/drm/ast/Makefile           |   2 +-
>>>  drivers/gpu/drm/ast/ast_drv.c          |  22 +-
>>>  drivers/gpu/drm/ast/ast_drv.h          |  17 --
>>>  drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
>>>  drivers/gpu/drm/ast/ast_main.c         |  30 ++-
>>>  drivers/gpu/drm/ast/ast_mode.c         |  21 --
>>>  drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
>>>  drivers/gpu/drm/drm_client.c           |  71 ++++-
>>>  drivers/gpu/drm/drm_fb_helper.c        |  14 +-
>>>  drivers/gpu/drm/mgag200/Makefile       |   2 +-
>>>  drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
>>>  drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
>>>  drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
>>>  drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
>>>  include/drm/drm_client.h               |   3 +
>>>  15 files changed, 154 insertions(+), 787 deletions(-)
>>>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
>>>  delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c
>>>
>>> --
>>> 2.21.0
>>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>>
> 
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Re: [PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Noralf Trønnes]

Den 04.07.2019 09.43, skrev Thomas Zimmermann:
> Hi
> 
> Am 03.07.19 um 21:27 schrieb Noralf Trønnes:
>>
>>
>> Den 03.07.2019 10.32, skrev Thomas Zimmermann:
>>> DRM client buffers are permanently mapped throughout their lifetime. This
>>> prevents us from using generic framebuffer emulation for devices with
>>> small dedicated video memory, such as ast or mgag200. With fb buffers
>>> permanently mapped, such devices often won't have enougth space left to
>>> display other content (e.g., X11).
>>>
>>> This patch set introduces unmappable DRM client buffers for framebuffer
>>> emulation with shadow buffers. While the shadow buffer remains in system
>>> memory permanently, the respective buffer object will only be mapped briefly
>>> during updates from the shadow buffer. Hence, the driver can relocate he
>>> buffer object among memory regions as needed.
>>>
>>> The default behoviour for DRM client buffers is still to be permanently
>>> mapped.
>>>
>>> The patch set converts ast and mgag200 to generic framebuffer emulation
>>> and removes a large amount of framebuffer code from these drivers. For
>>> bochs, a problem was reported where the driver could not display the console
>>> because it was pinned in system memory. [1] The patch set fixes this bug
>>> by converting bochs to use the shadow fb.
>>>
>>> The patch set has been tested on ast and mga200 HW.
>>>
>>
>> I've been thinking, this enables dirty tracking in DRM userspace for
>> these drivers since the dirty callback is now set on all framebuffers.
>> Is this OK? Should we add a drm_fbdev_generic_shadow_setup() that sets a
>> flag enabling the shadow buffer instead?
> 
> Fbdev emulation is special wrt framebuffer setup and there's no way to
> distinguish a regular FB from the fbdev's FB. I've been trying
> drm_fbdev_generic_shadow_setup(), but ended up duplicating
> functionality. The problem was that we cannot get state-flag arguments
> into drm_fb_helper_generic_probe().
> 
> There already is struct mode_config.prefer_shadow. It signals shadow FB
> rendering to userspace. The easiest solution is to add
> prefer_shadow_fbdev as well. If either flag is true, fbdev emulation
> would enable shadow buffering.

How about something like this:

diff --git a/drivers/gpu/drm/drm_fb_helper.c
b/drivers/gpu/drm/drm_fb_helper.c
index 1984e5c54d58..723fe56aa5f5 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -415,7 +415,8 @@ static void drm_fb_helper_dirty_work(struct
work_struct *work)
 		/* Generic fbdev uses a shadow buffer */
 		if (helper->buffer)
 			drm_fb_helper_dirty_blit_real(helper, &clip_copy);
-		helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
+		if (helper->fb->funcs->dirty)
+			helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
 	}
 }

@@ -2209,7 +2210,7 @@ int drm_fb_helper_generic_probe(struct
drm_fb_helper *fb_helper,
 #endif
 	drm_fb_helper_fill_info(fbi, fb_helper, sizes);

-	if (fb->funcs->dirty) {
+	if (fb->funcs->dirty || fb_helper->use_shadow) {
 		struct fb_ops *fbops;
 		void *shadow;

@@ -2310,6 +2311,44 @@ static const struct drm_client_funcs
drm_fbdev_client_funcs = {
 	.hotplug	= drm_fbdev_client_hotplug,
 };

+static int _drm_fbdev_generic_setup(struct drm_device *dev, unsigned
int preferred_bpp, bool use_shadow)
+{
+	struct drm_fb_helper *fb_helper;
+	int ret;
+
+	WARN(dev->fb_helper, "fb_helper is already set!\n");
+
+	if (!drm_fbdev_emulation)
+		return 0;
+
+	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
+	if (!fb_helper)
+		return -ENOMEM;
+
+	ret = drm_client_init(dev, &fb_helper->client, "fbdev",
&drm_fbdev_client_funcs);
+	if (ret) {
+		kfree(fb_helper);
+		DRM_DEV_ERROR(dev->dev, "Failed to register client: %d\n", ret);
+		return ret;
+	}
+
+	if (!preferred_bpp)
+		preferred_bpp = dev->mode_config.preferred_depth;
+	if (!preferred_bpp)
+		preferred_bpp = 32;
+	fb_helper->preferred_bpp = preferred_bpp;
+
+	fb_helper->use_shadow = use_shadow;
+
+	ret = drm_fbdev_client_hotplug(&fb_helper->client);
+	if (ret)
+		DRM_DEV_DEBUG(dev->dev, "client hotplug ret=%d\n", ret);
+
+	drm_client_register(&fb_helper->client);
+
+	return 0;
+}
+
 /**
  * drm_fbdev_generic_setup() - Setup generic fbdev emulation
  * @dev: DRM device
@@ -2338,38 +2377,13 @@ static const struct drm_client_funcs
drm_fbdev_client_funcs = {
  */
 int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int
preferred_bpp)
 {
-	struct drm_fb_helper *fb_helper;
-	int ret;
+	return _drm_fbdev_generic_setup(dev, preferred_bpp, false);
+}
+EXPORT_SYMBOL(drm_fbdev_generic_setup);

-	WARN(dev->fb_helper, "fb_helper is already set!\n");
-
-	if (!drm_fbdev_emulation)
-		return 0;
-
-	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
-	if (!fb_helper)
-		return -ENOMEM;
-
-	ret = drm_client_init(dev, &fb_helper->client, "fbdev",
&drm_fbdev_client_funcs);
-	if (ret) {
-		kfree(fb_helper);
-		DRM_DEV_ERROR(dev->dev, "Failed to register client: %d\n", ret);
-		return ret;
-	}
-
-	if (!preferred_bpp)
-		preferred_bpp = dev->mode_config.preferred_depth;
-	if (!preferred_bpp)
-		preferred_bpp = 32;
-	fb_helper->preferred_bpp = preferred_bpp;
-
-	ret = drm_fbdev_client_hotplug(&fb_helper->client);
-	if (ret)
-		DRM_DEV_DEBUG(dev->dev, "client hotplug ret=%d\n", ret);
-
-	drm_client_register(&fb_helper->client);
-
-	return 0;
+int drm_fbdev_generic_shadow_setup(struct drm_device *dev, unsigned int
preferred_bpp)
+{
+	return _drm_fbdev_generic_setup(dev, preferred_bpp, true);
 }
 EXPORT_SYMBOL(drm_fbdev_generic_setup);

diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index c8a8ae2a678a..39f063de8cbc 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -186,6 +186,8 @@ struct drm_fb_helper {
 	 * See also: @deferred_setup
 	 */
 	int preferred_bpp;
+
+	bool use_shadow;
 };

 static inline struct drm_fb_helper *


> 
> I'm not sure if we should check for the dirty() callback at all.
> 

Hm, why do you think that?

The thing with fbdev defio is that it only supports kmalloc and vmalloc
allocated memory (page->lru is avail.). This means that only the CMA
drivers can use defio without shadow memory. To keep things simple
everyone with a dirty() callback gets a shadow buffer.

Noralf.

> Best regards
> Thomas
> 
>> Really nice diffstat by the way :-)
>>
>> Noralf.
>>
>>> [1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html
>>>
>>> Thomas Zimmermann (5):
>>>   drm/client: Support unmapping of DRM client buffers
>>>   drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
>>>   drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
>>>   drm/bochs: Use shadow buffer for bochs framebuffer console
>>>   drm/mgag200: Replace struct mga_fbdev with generic framebuffer
>>>     emulation
>>>
>>>  drivers/gpu/drm/ast/Makefile           |   2 +-
>>>  drivers/gpu/drm/ast/ast_drv.c          |  22 +-
>>>  drivers/gpu/drm/ast/ast_drv.h          |  17 --
>>>  drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
>>>  drivers/gpu/drm/ast/ast_main.c         |  30 ++-
>>>  drivers/gpu/drm/ast/ast_mode.c         |  21 --
>>>  drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
>>>  drivers/gpu/drm/drm_client.c           |  71 ++++-
>>>  drivers/gpu/drm/drm_fb_helper.c        |  14 +-
>>>  drivers/gpu/drm/mgag200/Makefile       |   2 +-
>>>  drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
>>>  drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
>>>  drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
>>>  drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
>>>  include/drm/drm_client.h               |   3 +
>>>  15 files changed, 154 insertions(+), 787 deletions(-)
>>>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
>>>  delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c
>>>
>>> --
>>> 2.21.0
>>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>>
> 
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Thomas Zimmermann]

[-- Attachment #1.1.1: Type: text/plain, Size: 9373 bytes --]

Hi

Am 04.07.19 um 12:18 schrieb Noralf Trønnes:
> 
> 
> Den 04.07.2019 09.43, skrev Thomas Zimmermann:
>> Hi
>>
>> Am 03.07.19 um 21:27 schrieb Noralf Trønnes:
>>>
>>>
>>> Den 03.07.2019 10.32, skrev Thomas Zimmermann:
>>>> DRM client buffers are permanently mapped throughout their lifetime. This
>>>> prevents us from using generic framebuffer emulation for devices with
>>>> small dedicated video memory, such as ast or mgag200. With fb buffers
>>>> permanently mapped, such devices often won't have enougth space left to
>>>> display other content (e.g., X11).
>>>>
>>>> This patch set introduces unmappable DRM client buffers for framebuffer
>>>> emulation with shadow buffers. While the shadow buffer remains in system
>>>> memory permanently, the respective buffer object will only be mapped briefly
>>>> during updates from the shadow buffer. Hence, the driver can relocate he
>>>> buffer object among memory regions as needed.
>>>>
>>>> The default behoviour for DRM client buffers is still to be permanently
>>>> mapped.
>>>>
>>>> The patch set converts ast and mgag200 to generic framebuffer emulation
>>>> and removes a large amount of framebuffer code from these drivers. For
>>>> bochs, a problem was reported where the driver could not display the console
>>>> because it was pinned in system memory. [1] The patch set fixes this bug
>>>> by converting bochs to use the shadow fb.
>>>>
>>>> The patch set has been tested on ast and mga200 HW.
>>>>
>>>
>>> I've been thinking, this enables dirty tracking in DRM userspace for
>>> these drivers since the dirty callback is now set on all framebuffers.
>>> Is this OK? Should we add a drm_fbdev_generic_shadow_setup() that sets a
>>> flag enabling the shadow buffer instead?
>>
>> Fbdev emulation is special wrt framebuffer setup and there's no way to
>> distinguish a regular FB from the fbdev's FB. I've been trying
>> drm_fbdev_generic_shadow_setup(), but ended up duplicating
>> functionality. The problem was that we cannot get state-flag arguments
>> into drm_fb_helper_generic_probe().
>>
>> There already is struct mode_config.prefer_shadow. It signals shadow FB
>> rendering to userspace. The easiest solution is to add
>> prefer_shadow_fbdev as well. If either flag is true, fbdev emulation
>> would enable shadow buffering.
> 
> How about something like this:

I had something like that in mind, but maybe without a separate
function. I'll post my variant as part of the patch set's next iteration.

> diff --git a/drivers/gpu/drm/drm_fb_helper.c
> b/drivers/gpu/drm/drm_fb_helper.c
> index 1984e5c54d58..723fe56aa5f5 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -415,7 +415,8 @@ static void drm_fb_helper_dirty_work(struct
> work_struct *work)
>  		/* Generic fbdev uses a shadow buffer */
>  		if (helper->buffer)
>  			drm_fb_helper_dirty_blit_real(helper, &clip_copy);
> -		helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
> +		if (helper->fb->funcs->dirty)
> +			helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
>  	}
>  }
> 
> @@ -2209,7 +2210,7 @@ int drm_fb_helper_generic_probe(struct
> drm_fb_helper *fb_helper,
>  #endif
>  	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
> 
> -	if (fb->funcs->dirty) {
> +	if (fb->funcs->dirty || fb_helper->use_shadow) {
>  		struct fb_ops *fbops;
>  		void *shadow;
> 
> @@ -2310,6 +2311,44 @@ static const struct drm_client_funcs
> drm_fbdev_client_funcs = {
>  	.hotplug	= drm_fbdev_client_hotplug,
>  };
> 
> +static int _drm_fbdev_generic_setup(struct drm_device *dev, unsigned
> int preferred_bpp, bool use_shadow)
> +{
> +	struct drm_fb_helper *fb_helper;
> +	int ret;
> +
> +	WARN(dev->fb_helper, "fb_helper is already set!\n");
> +
> +	if (!drm_fbdev_emulation)
> +		return 0;
> +
> +	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
> +	if (!fb_helper)
> +		return -ENOMEM;
> +
> +	ret = drm_client_init(dev, &fb_helper->client, "fbdev",
> &drm_fbdev_client_funcs);
> +	if (ret) {
> +		kfree(fb_helper);
> +		DRM_DEV_ERROR(dev->dev, "Failed to register client: %d\n", ret);
> +		return ret;
> +	}
> +
> +	if (!preferred_bpp)
> +		preferred_bpp = dev->mode_config.preferred_depth;
> +	if (!preferred_bpp)
> +		preferred_bpp = 32;
> +	fb_helper->preferred_bpp = preferred_bpp;
> +
> +	fb_helper->use_shadow = use_shadow;
> +
> +	ret = drm_fbdev_client_hotplug(&fb_helper->client);
> +	if (ret)
> +		DRM_DEV_DEBUG(dev->dev, "client hotplug ret=%d\n", ret);
> +
> +	drm_client_register(&fb_helper->client);
> +
> +	return 0;
> +}
> +
>  /**
>   * drm_fbdev_generic_setup() - Setup generic fbdev emulation
>   * @dev: DRM device
> @@ -2338,38 +2377,13 @@ static const struct drm_client_funcs
> drm_fbdev_client_funcs = {
>   */
>  int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int
> preferred_bpp)
>  {
> -	struct drm_fb_helper *fb_helper;
> -	int ret;
> +	return _drm_fbdev_generic_setup(dev, preferred_bpp, false);
> +}
> +EXPORT_SYMBOL(drm_fbdev_generic_setup);
> 
> -	WARN(dev->fb_helper, "fb_helper is already set!\n");
> -
> -	if (!drm_fbdev_emulation)
> -		return 0;
> -
> -	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
> -	if (!fb_helper)
> -		return -ENOMEM;
> -
> -	ret = drm_client_init(dev, &fb_helper->client, "fbdev",
> &drm_fbdev_client_funcs);
> -	if (ret) {
> -		kfree(fb_helper);
> -		DRM_DEV_ERROR(dev->dev, "Failed to register client: %d\n", ret);
> -		return ret;
> -	}
> -
> -	if (!preferred_bpp)
> -		preferred_bpp = dev->mode_config.preferred_depth;
> -	if (!preferred_bpp)
> -		preferred_bpp = 32;
> -	fb_helper->preferred_bpp = preferred_bpp;
> -
> -	ret = drm_fbdev_client_hotplug(&fb_helper->client);
> -	if (ret)
> -		DRM_DEV_DEBUG(dev->dev, "client hotplug ret=%d\n", ret);
> -
> -	drm_client_register(&fb_helper->client);
> -
> -	return 0;
> +int drm_fbdev_generic_shadow_setup(struct drm_device *dev, unsigned int
> preferred_bpp)
> +{
> +	return _drm_fbdev_generic_setup(dev, preferred_bpp, true);
>  }
>  EXPORT_SYMBOL(drm_fbdev_generic_setup);
> 
> diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
> index c8a8ae2a678a..39f063de8cbc 100644
> --- a/include/drm/drm_fb_helper.h
> +++ b/include/drm/drm_fb_helper.h
> @@ -186,6 +186,8 @@ struct drm_fb_helper {
>  	 * See also: @deferred_setup
>  	 */
>  	int preferred_bpp;
> +
> +	bool use_shadow;
>  };
> 
>  static inline struct drm_fb_helper *
> 
> 
>>
>> I'm not sure if we should check for the dirty() callback at all.
>>
> 
> Hm, why do you think that?

Drivers may already come with their own shadow buffer. Cirrus is an
example of that. It uses shmem buffer objects as shadow fbs and
internally updates the device frame buffer in its dirty callback. Using
dirty() to select the shadow fbdev adds another buffer (and another
memcpy) for no reason.

Best regards
Thomas

> The thing with fbdev defio is that it only supports kmalloc and vmalloc
> allocated memory (page->lru is avail.). This means that only the CMA
> drivers can use defio without shadow memory. To keep things simple
> everyone with a dirty() callback gets a shadow buffer.
> 
> Noralf.
> 
>> Best regards
>> Thomas
>>
>>> Really nice diffstat by the way :-)
>>>
>>> Noralf.
>>>
>>>> [1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html
>>>>
>>>> Thomas Zimmermann (5):
>>>>   drm/client: Support unmapping of DRM client buffers
>>>>   drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
>>>>   drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
>>>>   drm/bochs: Use shadow buffer for bochs framebuffer console
>>>>   drm/mgag200: Replace struct mga_fbdev with generic framebuffer
>>>>     emulation
>>>>
>>>>  drivers/gpu/drm/ast/Makefile           |   2 +-
>>>>  drivers/gpu/drm/ast/ast_drv.c          |  22 +-
>>>>  drivers/gpu/drm/ast/ast_drv.h          |  17 --
>>>>  drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
>>>>  drivers/gpu/drm/ast/ast_main.c         |  30 ++-
>>>>  drivers/gpu/drm/ast/ast_mode.c         |  21 --
>>>>  drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
>>>>  drivers/gpu/drm/drm_client.c           |  71 ++++-
>>>>  drivers/gpu/drm/drm_fb_helper.c        |  14 +-
>>>>  drivers/gpu/drm/mgag200/Makefile       |   2 +-
>>>>  drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
>>>>  drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
>>>>  drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
>>>>  drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
>>>>  include/drm/drm_client.h               |   3 +
>>>>  15 files changed, 154 insertions(+), 787 deletions(-)
>>>>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
>>>>  delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c
>>>>
>>>> --
>>>> 2.21.0
>>>>
>>> _______________________________________________
>>> dri-devel mailing list
>>> dri-devel@lists.freedesktop.org
>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>>>
>>

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)


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Re: [PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Thomas Zimmermann]

[-- Attachment #1.1.1: Type: text/plain, Size: 9373 bytes --]

Hi

Am 04.07.19 um 12:18 schrieb Noralf Trønnes:
> 
> 
> Den 04.07.2019 09.43, skrev Thomas Zimmermann:
>> Hi
>>
>> Am 03.07.19 um 21:27 schrieb Noralf Trønnes:
>>>
>>>
>>> Den 03.07.2019 10.32, skrev Thomas Zimmermann:
>>>> DRM client buffers are permanently mapped throughout their lifetime. This
>>>> prevents us from using generic framebuffer emulation for devices with
>>>> small dedicated video memory, such as ast or mgag200. With fb buffers
>>>> permanently mapped, such devices often won't have enougth space left to
>>>> display other content (e.g., X11).
>>>>
>>>> This patch set introduces unmappable DRM client buffers for framebuffer
>>>> emulation with shadow buffers. While the shadow buffer remains in system
>>>> memory permanently, the respective buffer object will only be mapped briefly
>>>> during updates from the shadow buffer. Hence, the driver can relocate he
>>>> buffer object among memory regions as needed.
>>>>
>>>> The default behoviour for DRM client buffers is still to be permanently
>>>> mapped.
>>>>
>>>> The patch set converts ast and mgag200 to generic framebuffer emulation
>>>> and removes a large amount of framebuffer code from these drivers. For
>>>> bochs, a problem was reported where the driver could not display the console
>>>> because it was pinned in system memory. [1] The patch set fixes this bug
>>>> by converting bochs to use the shadow fb.
>>>>
>>>> The patch set has been tested on ast and mga200 HW.
>>>>
>>>
>>> I've been thinking, this enables dirty tracking in DRM userspace for
>>> these drivers since the dirty callback is now set on all framebuffers.
>>> Is this OK? Should we add a drm_fbdev_generic_shadow_setup() that sets a
>>> flag enabling the shadow buffer instead?
>>
>> Fbdev emulation is special wrt framebuffer setup and there's no way to
>> distinguish a regular FB from the fbdev's FB. I've been trying
>> drm_fbdev_generic_shadow_setup(), but ended up duplicating
>> functionality. The problem was that we cannot get state-flag arguments
>> into drm_fb_helper_generic_probe().
>>
>> There already is struct mode_config.prefer_shadow. It signals shadow FB
>> rendering to userspace. The easiest solution is to add
>> prefer_shadow_fbdev as well. If either flag is true, fbdev emulation
>> would enable shadow buffering.
> 
> How about something like this:

I had something like that in mind, but maybe without a separate
function. I'll post my variant as part of the patch set's next iteration.

> diff --git a/drivers/gpu/drm/drm_fb_helper.c
> b/drivers/gpu/drm/drm_fb_helper.c
> index 1984e5c54d58..723fe56aa5f5 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -415,7 +415,8 @@ static void drm_fb_helper_dirty_work(struct
> work_struct *work)
>  		/* Generic fbdev uses a shadow buffer */
>  		if (helper->buffer)
>  			drm_fb_helper_dirty_blit_real(helper, &clip_copy);
> -		helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
> +		if (helper->fb->funcs->dirty)
> +			helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
>  	}
>  }
> 
> @@ -2209,7 +2210,7 @@ int drm_fb_helper_generic_probe(struct
> drm_fb_helper *fb_helper,
>  #endif
>  	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
> 
> -	if (fb->funcs->dirty) {
> +	if (fb->funcs->dirty || fb_helper->use_shadow) {
>  		struct fb_ops *fbops;
>  		void *shadow;
> 
> @@ -2310,6 +2311,44 @@ static const struct drm_client_funcs
> drm_fbdev_client_funcs = {
>  	.hotplug	= drm_fbdev_client_hotplug,
>  };
> 
> +static int _drm_fbdev_generic_setup(struct drm_device *dev, unsigned
> int preferred_bpp, bool use_shadow)
> +{
> +	struct drm_fb_helper *fb_helper;
> +	int ret;
> +
> +	WARN(dev->fb_helper, "fb_helper is already set!\n");
> +
> +	if (!drm_fbdev_emulation)
> +		return 0;
> +
> +	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
> +	if (!fb_helper)
> +		return -ENOMEM;
> +
> +	ret = drm_client_init(dev, &fb_helper->client, "fbdev",
> &drm_fbdev_client_funcs);
> +	if (ret) {
> +		kfree(fb_helper);
> +		DRM_DEV_ERROR(dev->dev, "Failed to register client: %d\n", ret);
> +		return ret;
> +	}
> +
> +	if (!preferred_bpp)
> +		preferred_bpp = dev->mode_config.preferred_depth;
> +	if (!preferred_bpp)
> +		preferred_bpp = 32;
> +	fb_helper->preferred_bpp = preferred_bpp;
> +
> +	fb_helper->use_shadow = use_shadow;
> +
> +	ret = drm_fbdev_client_hotplug(&fb_helper->client);
> +	if (ret)
> +		DRM_DEV_DEBUG(dev->dev, "client hotplug ret=%d\n", ret);
> +
> +	drm_client_register(&fb_helper->client);
> +
> +	return 0;
> +}
> +
>  /**
>   * drm_fbdev_generic_setup() - Setup generic fbdev emulation
>   * @dev: DRM device
> @@ -2338,38 +2377,13 @@ static const struct drm_client_funcs
> drm_fbdev_client_funcs = {
>   */
>  int drm_fbdev_generic_setup(struct drm_device *dev, unsigned int
> preferred_bpp)
>  {
> -	struct drm_fb_helper *fb_helper;
> -	int ret;
> +	return _drm_fbdev_generic_setup(dev, preferred_bpp, false);
> +}
> +EXPORT_SYMBOL(drm_fbdev_generic_setup);
> 
> -	WARN(dev->fb_helper, "fb_helper is already set!\n");
> -
> -	if (!drm_fbdev_emulation)
> -		return 0;
> -
> -	fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL);
> -	if (!fb_helper)
> -		return -ENOMEM;
> -
> -	ret = drm_client_init(dev, &fb_helper->client, "fbdev",
> &drm_fbdev_client_funcs);
> -	if (ret) {
> -		kfree(fb_helper);
> -		DRM_DEV_ERROR(dev->dev, "Failed to register client: %d\n", ret);
> -		return ret;
> -	}
> -
> -	if (!preferred_bpp)
> -		preferred_bpp = dev->mode_config.preferred_depth;
> -	if (!preferred_bpp)
> -		preferred_bpp = 32;
> -	fb_helper->preferred_bpp = preferred_bpp;
> -
> -	ret = drm_fbdev_client_hotplug(&fb_helper->client);
> -	if (ret)
> -		DRM_DEV_DEBUG(dev->dev, "client hotplug ret=%d\n", ret);
> -
> -	drm_client_register(&fb_helper->client);
> -
> -	return 0;
> +int drm_fbdev_generic_shadow_setup(struct drm_device *dev, unsigned int
> preferred_bpp)
> +{
> +	return _drm_fbdev_generic_setup(dev, preferred_bpp, true);
>  }
>  EXPORT_SYMBOL(drm_fbdev_generic_setup);
> 
> diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
> index c8a8ae2a678a..39f063de8cbc 100644
> --- a/include/drm/drm_fb_helper.h
> +++ b/include/drm/drm_fb_helper.h
> @@ -186,6 +186,8 @@ struct drm_fb_helper {
>  	 * See also: @deferred_setup
>  	 */
>  	int preferred_bpp;
> +
> +	bool use_shadow;
>  };
> 
>  static inline struct drm_fb_helper *
> 
> 
>>
>> I'm not sure if we should check for the dirty() callback at all.
>>
> 
> Hm, why do you think that?

Drivers may already come with their own shadow buffer. Cirrus is an
example of that. It uses shmem buffer objects as shadow fbs and
internally updates the device frame buffer in its dirty callback. Using
dirty() to select the shadow fbdev adds another buffer (and another
memcpy) for no reason.

Best regards
Thomas

> The thing with fbdev defio is that it only supports kmalloc and vmalloc
> allocated memory (page->lru is avail.). This means that only the CMA
> drivers can use defio without shadow memory. To keep things simple
> everyone with a dirty() callback gets a shadow buffer.
> 
> Noralf.
> 
>> Best regards
>> Thomas
>>
>>> Really nice diffstat by the way :-)
>>>
>>> Noralf.
>>>
>>>> [1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html
>>>>
>>>> Thomas Zimmermann (5):
>>>>   drm/client: Support unmapping of DRM client buffers
>>>>   drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
>>>>   drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
>>>>   drm/bochs: Use shadow buffer for bochs framebuffer console
>>>>   drm/mgag200: Replace struct mga_fbdev with generic framebuffer
>>>>     emulation
>>>>
>>>>  drivers/gpu/drm/ast/Makefile           |   2 +-
>>>>  drivers/gpu/drm/ast/ast_drv.c          |  22 +-
>>>>  drivers/gpu/drm/ast/ast_drv.h          |  17 --
>>>>  drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
>>>>  drivers/gpu/drm/ast/ast_main.c         |  30 ++-
>>>>  drivers/gpu/drm/ast/ast_mode.c         |  21 --
>>>>  drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
>>>>  drivers/gpu/drm/drm_client.c           |  71 ++++-
>>>>  drivers/gpu/drm/drm_fb_helper.c        |  14 +-
>>>>  drivers/gpu/drm/mgag200/Makefile       |   2 +-
>>>>  drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
>>>>  drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
>>>>  drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
>>>>  drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
>>>>  include/drm/drm_client.h               |   3 +
>>>>  15 files changed, 154 insertions(+), 787 deletions(-)
>>>>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
>>>>  delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c
>>>>
>>>> --
>>>> 2.21.0
>>>>
>>> _______________________________________________
>>> dri-devel mailing list
>>> dri-devel@lists.freedesktop.org
>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>>>
>>

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)


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https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Noralf Trønnes]

Den 04.07.2019 13.10, skrev Thomas Zimmermann:
> Hi
> 
> Am 04.07.19 um 12:18 schrieb Noralf Trønnes:
>>
>>
>> Den 04.07.2019 09.43, skrev Thomas Zimmermann:
>>> Hi
>>>
>>> Am 03.07.19 um 21:27 schrieb Noralf Trønnes:
>>>>
>>>>
>>>> Den 03.07.2019 10.32, skrev Thomas Zimmermann:
>>>>> DRM client buffers are permanently mapped throughout their lifetime. This
>>>>> prevents us from using generic framebuffer emulation for devices with
>>>>> small dedicated video memory, such as ast or mgag200. With fb buffers
>>>>> permanently mapped, such devices often won't have enougth space left to
>>>>> display other content (e.g., X11).
>>>>>
>>>>> This patch set introduces unmappable DRM client buffers for framebuffer
>>>>> emulation with shadow buffers. While the shadow buffer remains in system
>>>>> memory permanently, the respective buffer object will only be mapped briefly
>>>>> during updates from the shadow buffer. Hence, the driver can relocate he
>>>>> buffer object among memory regions as needed.
>>>>>
>>>>> The default behoviour for DRM client buffers is still to be permanently
>>>>> mapped.
>>>>>
>>>>> The patch set converts ast and mgag200 to generic framebuffer emulation
>>>>> and removes a large amount of framebuffer code from these drivers. For
>>>>> bochs, a problem was reported where the driver could not display the console
>>>>> because it was pinned in system memory. [1] The patch set fixes this bug
>>>>> by converting bochs to use the shadow fb.
>>>>>
>>>>> The patch set has been tested on ast and mga200 HW.
>>>>>
>>>>
>>>> I've been thinking, this enables dirty tracking in DRM userspace for
>>>> these drivers since the dirty callback is now set on all framebuffers.
>>>> Is this OK? Should we add a drm_fbdev_generic_shadow_setup() that sets a
>>>> flag enabling the shadow buffer instead?
>>>
>>> Fbdev emulation is special wrt framebuffer setup and there's no way to
>>> distinguish a regular FB from the fbdev's FB. I've been trying
>>> drm_fbdev_generic_shadow_setup(), but ended up duplicating
>>> functionality. The problem was that we cannot get state-flag arguments
>>> into drm_fb_helper_generic_probe().
>>>
>>> There already is struct mode_config.prefer_shadow. It signals shadow FB
>>> rendering to userspace. The easiest solution is to add
>>> prefer_shadow_fbdev as well. If either flag is true, fbdev emulation
>>> would enable shadow buffering.
>>
>> How about something like this:
> 
> I had something like that in mind, but maybe without a separate
> function. I'll post my variant as part of the patch set's next iteration.
> 

<snip>

>>>
>>> I'm not sure if we should check for the dirty() callback at all.
>>>
>>
>> Hm, why do you think that?
> 
> Drivers may already come with their own shadow buffer. Cirrus is an
> example of that. It uses shmem buffer objects as shadow fbs and
> internally updates the device frame buffer in its dirty callback. Using
> dirty() to select the shadow fbdev adds another buffer (and another
> memcpy) for no reason.

Cirruc uses shmem buffers and they won't work with fbdev defio (both use
page->lru). shmem is the reason I added shadow buffering to generic
fbdev in the first place. It will now work with whatever backing buffer
the driver uses, as long as it can provide a virtual address on the dumb
buffer (not the case with rockchip for instance, due to limited virtual
address space).

Noralf.

> 
> Best regards
> Thomas
> 
>> The thing with fbdev defio is that it only supports kmalloc and vmalloc
>> allocated memory (page->lru is avail.). This means that only the CMA
>> drivers can use defio without shadow memory. To keep things simple
>> everyone with a dirty() callback gets a shadow buffer.
>>
>> Noralf.
>>
>>> Best regards
>>> Thomas
>>>
>>>> Really nice diffstat by the way :-)
>>>>
>>>> Noralf.
>>>>
>>>>> [1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html
>>>>>
>>>>> Thomas Zimmermann (5):
>>>>>   drm/client: Support unmapping of DRM client buffers
>>>>>   drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
>>>>>   drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
>>>>>   drm/bochs: Use shadow buffer for bochs framebuffer console
>>>>>   drm/mgag200: Replace struct mga_fbdev with generic framebuffer
>>>>>     emulation
>>>>>
>>>>>  drivers/gpu/drm/ast/Makefile           |   2 +-
>>>>>  drivers/gpu/drm/ast/ast_drv.c          |  22 +-
>>>>>  drivers/gpu/drm/ast/ast_drv.h          |  17 --
>>>>>  drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
>>>>>  drivers/gpu/drm/ast/ast_main.c         |  30 ++-
>>>>>  drivers/gpu/drm/ast/ast_mode.c         |  21 --
>>>>>  drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
>>>>>  drivers/gpu/drm/drm_client.c           |  71 ++++-
>>>>>  drivers/gpu/drm/drm_fb_helper.c        |  14 +-
>>>>>  drivers/gpu/drm/mgag200/Makefile       |   2 +-
>>>>>  drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
>>>>>  drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
>>>>>  drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
>>>>>  drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
>>>>>  include/drm/drm_client.h               |   3 +
>>>>>  15 files changed, 154 insertions(+), 787 deletions(-)
>>>>>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
>>>>>  delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c
>>>>>
>>>>> --
>>>>> 2.21.0
>>>>>
>>>> _______________________________________________
>>>> dri-devel mailing list
>>>> dri-devel@lists.freedesktop.org
>>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>>>>
>>>
> 
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

Re: [PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Noralf Trønnes]

Den 04.07.2019 13.10, skrev Thomas Zimmermann:
> Hi
> 
> Am 04.07.19 um 12:18 schrieb Noralf Trønnes:
>>
>>
>> Den 04.07.2019 09.43, skrev Thomas Zimmermann:
>>> Hi
>>>
>>> Am 03.07.19 um 21:27 schrieb Noralf Trønnes:
>>>>
>>>>
>>>> Den 03.07.2019 10.32, skrev Thomas Zimmermann:
>>>>> DRM client buffers are permanently mapped throughout their lifetime. This
>>>>> prevents us from using generic framebuffer emulation for devices with
>>>>> small dedicated video memory, such as ast or mgag200. With fb buffers
>>>>> permanently mapped, such devices often won't have enougth space left to
>>>>> display other content (e.g., X11).
>>>>>
>>>>> This patch set introduces unmappable DRM client buffers for framebuffer
>>>>> emulation with shadow buffers. While the shadow buffer remains in system
>>>>> memory permanently, the respective buffer object will only be mapped briefly
>>>>> during updates from the shadow buffer. Hence, the driver can relocate he
>>>>> buffer object among memory regions as needed.
>>>>>
>>>>> The default behoviour for DRM client buffers is still to be permanently
>>>>> mapped.
>>>>>
>>>>> The patch set converts ast and mgag200 to generic framebuffer emulation
>>>>> and removes a large amount of framebuffer code from these drivers. For
>>>>> bochs, a problem was reported where the driver could not display the console
>>>>> because it was pinned in system memory. [1] The patch set fixes this bug
>>>>> by converting bochs to use the shadow fb.
>>>>>
>>>>> The patch set has been tested on ast and mga200 HW.
>>>>>
>>>>
>>>> I've been thinking, this enables dirty tracking in DRM userspace for
>>>> these drivers since the dirty callback is now set on all framebuffers.
>>>> Is this OK? Should we add a drm_fbdev_generic_shadow_setup() that sets a
>>>> flag enabling the shadow buffer instead?
>>>
>>> Fbdev emulation is special wrt framebuffer setup and there's no way to
>>> distinguish a regular FB from the fbdev's FB. I've been trying
>>> drm_fbdev_generic_shadow_setup(), but ended up duplicating
>>> functionality. The problem was that we cannot get state-flag arguments
>>> into drm_fb_helper_generic_probe().
>>>
>>> There already is struct mode_config.prefer_shadow. It signals shadow FB
>>> rendering to userspace. The easiest solution is to add
>>> prefer_shadow_fbdev as well. If either flag is true, fbdev emulation
>>> would enable shadow buffering.
>>
>> How about something like this:
> 
> I had something like that in mind, but maybe without a separate
> function. I'll post my variant as part of the patch set's next iteration.
> 

<snip>

>>>
>>> I'm not sure if we should check for the dirty() callback at all.
>>>
>>
>> Hm, why do you think that?
> 
> Drivers may already come with their own shadow buffer. Cirrus is an
> example of that. It uses shmem buffer objects as shadow fbs and
> internally updates the device frame buffer in its dirty callback. Using
> dirty() to select the shadow fbdev adds another buffer (and another
> memcpy) for no reason.

Cirruc uses shmem buffers and they won't work with fbdev defio (both use
page->lru). shmem is the reason I added shadow buffering to generic
fbdev in the first place. It will now work with whatever backing buffer
the driver uses, as long as it can provide a virtual address on the dumb
buffer (not the case with rockchip for instance, due to limited virtual
address space).

Noralf.

> 
> Best regards
> Thomas
> 
>> The thing with fbdev defio is that it only supports kmalloc and vmalloc
>> allocated memory (page->lru is avail.). This means that only the CMA
>> drivers can use defio without shadow memory. To keep things simple
>> everyone with a dirty() callback gets a shadow buffer.
>>
>> Noralf.
>>
>>> Best regards
>>> Thomas
>>>
>>>> Really nice diffstat by the way :-)
>>>>
>>>> Noralf.
>>>>
>>>>> [1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html
>>>>>
>>>>> Thomas Zimmermann (5):
>>>>>   drm/client: Support unmapping of DRM client buffers
>>>>>   drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
>>>>>   drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
>>>>>   drm/bochs: Use shadow buffer for bochs framebuffer console
>>>>>   drm/mgag200: Replace struct mga_fbdev with generic framebuffer
>>>>>     emulation
>>>>>
>>>>>  drivers/gpu/drm/ast/Makefile           |   2 +-
>>>>>  drivers/gpu/drm/ast/ast_drv.c          |  22 +-
>>>>>  drivers/gpu/drm/ast/ast_drv.h          |  17 --
>>>>>  drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
>>>>>  drivers/gpu/drm/ast/ast_main.c         |  30 ++-
>>>>>  drivers/gpu/drm/ast/ast_mode.c         |  21 --
>>>>>  drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
>>>>>  drivers/gpu/drm/drm_client.c           |  71 ++++-
>>>>>  drivers/gpu/drm/drm_fb_helper.c        |  14 +-
>>>>>  drivers/gpu/drm/mgag200/Makefile       |   2 +-
>>>>>  drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
>>>>>  drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
>>>>>  drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
>>>>>  drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
>>>>>  include/drm/drm_client.h               |   3 +
>>>>>  15 files changed, 154 insertions(+), 787 deletions(-)
>>>>>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
>>>>>  delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c
>>>>>
>>>>> --
>>>>> 2.21.0
>>>>>
>>>> _______________________________________________
>>>> dri-devel mailing list
>>>> dri-devel@lists.freedesktop.org
>>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>>>>
>>>
> 
_______________________________________________
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Re: [PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Thomas Zimmermann]

[-- Attachment #1.1.1: Type: text/plain, Size: 3542 bytes --]

Hi

Am 04.07.19 um 16:15 schrieb Noralf Trønnes:
>>> Hm, why do you think that?
>>
>> Drivers may already come with their own shadow buffer. Cirrus is an
>> example of that. It uses shmem buffer objects as shadow fbs and
>> internally updates the device frame buffer in its dirty callback. Using
>> dirty() to select the shadow fbdev adds another buffer (and another
>> memcpy) for no reason.
> 
> Cirruc uses shmem buffers and they won't work with fbdev defio (both use
> page->lru). shmem is the reason I added shadow buffering to generic
> fbdev in the first place. It will now work with whatever backing buffer
> the driver uses, as long as it can provide a virtual address on the dumb
> buffer (not the case with rockchip for instance, due to limited virtual
> address space).

OK, I see. Thanks or clarifying.

Best regards
Thomas

> Noralf.
> 
>>
>> Best regards
>> Thomas
>>
>>> The thing with fbdev defio is that it only supports kmalloc and vmalloc
>>> allocated memory (page->lru is avail.). This means that only the CMA
>>> drivers can use defio without shadow memory. To keep things simple
>>> everyone with a dirty() callback gets a shadow buffer.
>>>
>>> Noralf.
>>>
>>>> Best regards
>>>> Thomas
>>>>
>>>>> Really nice diffstat by the way :-)
>>>>>
>>>>> Noralf.
>>>>>
>>>>>> [1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html
>>>>>>
>>>>>> Thomas Zimmermann (5):
>>>>>>   drm/client: Support unmapping of DRM client buffers
>>>>>>   drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
>>>>>>   drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
>>>>>>   drm/bochs: Use shadow buffer for bochs framebuffer console
>>>>>>   drm/mgag200: Replace struct mga_fbdev with generic framebuffer
>>>>>>     emulation
>>>>>>
>>>>>>  drivers/gpu/drm/ast/Makefile           |   2 +-
>>>>>>  drivers/gpu/drm/ast/ast_drv.c          |  22 +-
>>>>>>  drivers/gpu/drm/ast/ast_drv.h          |  17 --
>>>>>>  drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
>>>>>>  drivers/gpu/drm/ast/ast_main.c         |  30 ++-
>>>>>>  drivers/gpu/drm/ast/ast_mode.c         |  21 --
>>>>>>  drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
>>>>>>  drivers/gpu/drm/drm_client.c           |  71 ++++-
>>>>>>  drivers/gpu/drm/drm_fb_helper.c        |  14 +-
>>>>>>  drivers/gpu/drm/mgag200/Makefile       |   2 +-
>>>>>>  drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
>>>>>>  drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
>>>>>>  drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
>>>>>>  drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
>>>>>>  include/drm/drm_client.h               |   3 +
>>>>>>  15 files changed, 154 insertions(+), 787 deletions(-)
>>>>>>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
>>>>>>  delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c
>>>>>>
>>>>>> --
>>>>>> 2.21.0
>>>>>>
>>>>> _______________________________________________
>>>>> dri-devel mailing list
>>>>> dri-devel@lists.freedesktop.org
>>>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>>>>>
>>>>
>>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)


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Re: [PATCH 0/5] Unmappable DRM client buffers for fbdev emulation

[Thomas Zimmermann]

[-- Attachment #1.1.1: Type: text/plain, Size: 3542 bytes --]

Hi

Am 04.07.19 um 16:15 schrieb Noralf Trønnes:
>>> Hm, why do you think that?
>>
>> Drivers may already come with their own shadow buffer. Cirrus is an
>> example of that. It uses shmem buffer objects as shadow fbs and
>> internally updates the device frame buffer in its dirty callback. Using
>> dirty() to select the shadow fbdev adds another buffer (and another
>> memcpy) for no reason.
> 
> Cirruc uses shmem buffers and they won't work with fbdev defio (both use
> page->lru). shmem is the reason I added shadow buffering to generic
> fbdev in the first place. It will now work with whatever backing buffer
> the driver uses, as long as it can provide a virtual address on the dumb
> buffer (not the case with rockchip for instance, due to limited virtual
> address space).

OK, I see. Thanks or clarifying.

Best regards
Thomas

> Noralf.
> 
>>
>> Best regards
>> Thomas
>>
>>> The thing with fbdev defio is that it only supports kmalloc and vmalloc
>>> allocated memory (page->lru is avail.). This means that only the CMA
>>> drivers can use defio without shadow memory. To keep things simple
>>> everyone with a dirty() callback gets a shadow buffer.
>>>
>>> Noralf.
>>>
>>>> Best regards
>>>> Thomas
>>>>
>>>>> Really nice diffstat by the way :-)
>>>>>
>>>>> Noralf.
>>>>>
>>>>>> [1] https://lists.freedesktop.org/archives/dri-devel/2019-June/224423.html
>>>>>>
>>>>>> Thomas Zimmermann (5):
>>>>>>   drm/client: Support unmapping of DRM client buffers
>>>>>>   drm/fb-helper: Unmap BO for shadow-buffered framebuffer console
>>>>>>   drm/ast: Replace struct ast_fbdev with generic framebuffer emulation
>>>>>>   drm/bochs: Use shadow buffer for bochs framebuffer console
>>>>>>   drm/mgag200: Replace struct mga_fbdev with generic framebuffer
>>>>>>     emulation
>>>>>>
>>>>>>  drivers/gpu/drm/ast/Makefile           |   2 +-
>>>>>>  drivers/gpu/drm/ast/ast_drv.c          |  22 +-
>>>>>>  drivers/gpu/drm/ast/ast_drv.h          |  17 --
>>>>>>  drivers/gpu/drm/ast/ast_fb.c           | 341 -------------------------
>>>>>>  drivers/gpu/drm/ast/ast_main.c         |  30 ++-
>>>>>>  drivers/gpu/drm/ast/ast_mode.c         |  21 --
>>>>>>  drivers/gpu/drm/bochs/bochs_kms.c      |   2 +-
>>>>>>  drivers/gpu/drm/drm_client.c           |  71 ++++-
>>>>>>  drivers/gpu/drm/drm_fb_helper.c        |  14 +-
>>>>>>  drivers/gpu/drm/mgag200/Makefile       |   2 +-
>>>>>>  drivers/gpu/drm/mgag200/mgag200_drv.h  |  19 --
>>>>>>  drivers/gpu/drm/mgag200/mgag200_fb.c   | 309 ----------------------
>>>>>>  drivers/gpu/drm/mgag200/mgag200_main.c |  61 +++--
>>>>>>  drivers/gpu/drm/mgag200/mgag200_mode.c |  27 --
>>>>>>  include/drm/drm_client.h               |   3 +
>>>>>>  15 files changed, 154 insertions(+), 787 deletions(-)
>>>>>>  delete mode 100644 drivers/gpu/drm/ast/ast_fb.c
>>>>>>  delete mode 100644 drivers/gpu/drm/mgag200/mgag200_fb.c
>>>>>>
>>>>>> --
>>>>>> 2.21.0
>>>>>>
>>>>> _______________________________________________
>>>>> dri-devel mailing list
>>>>> dri-devel@lists.freedesktop.org
>>>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>>>>>
>>>>
>>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Linux GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
GF: Felix Imendörffer, Mary Higgins, Sri Rasiah
HRB 21284 (AG Nürnberg)


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