[PATCH 1/2] iosys-map: Add getter functions for virtual addresses

[PATCH 1/2] iosys-map: Add getter functions for virtual addresses

[oushixiong1025]

From: Shixiong Ou <oushixiong@kylinos.cn>

Add iosys_map_get_vaddr() and iosys_map_get_vaddr_iomem() as the
counterparts to iosys_map_set_vaddr() and iosys_map_set_vaddr_iomem().

This allows drivers to use the iosys_map abstraction layer properly
instead of directly accessing the structure members, improving code
maintainability and safety.

Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>
---
 include/linux/iosys-map.h | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/include/linux/iosys-map.h b/include/linux/iosys-map.h
index 3e85afe794c0..658d5038498a 100644
--- a/include/linux/iosys-map.h
+++ b/include/linux/iosys-map.h
@@ -200,6 +200,42 @@ static inline void iosys_map_set_vaddr_iomem(struct iosys_map *map,
 	map->is_iomem = true;
 }
 
+/**
+ * iosys_map_get_vaddr - Gets the virtual address of a system-memory mapping
+ * @map:	The iosys_map structure
+ *
+ * Returns the system-memory address. The caller must ensure the mapping
+ * refers to system memory (not I/O memory).
+ *
+ * Returns:
+ * The system-memory address, or NULL if the mapping is not set or refers
+ * to I/O memory.
+ */
+static inline void *iosys_map_get_vaddr(const struct iosys_map *map)
+{
+	if (WARN_ON(map->is_iomem))
+		return NULL;
+	return map->vaddr;
+}
+
+/**
+ * iosys_map_get_vaddr_iomem - Gets the virtual address of an I/O-memory mapping
+ * @map:	The iosys_map structure
+ *
+ * Returns the I/O-memory address. The caller must ensure the mapping
+ * refers to I/O memory (not system memory).
+ *
+ * Returns:
+ * The I/O-memory address, or NULL if the mapping is not set or refers
+ * to system memory.
+ */
+static inline void __iomem *iosys_map_get_vaddr_iomem(const struct iosys_map *map)
+{
+	if (WARN_ON(!map->is_iomem))
+		return NULL;
+	return map->vaddr_iomem;
+}
+
 /**
  * iosys_map_is_equal - Compares two iosys mapping structures for equality
  * @lhs:	The iosys_map structure
-- 
2.25.1


No virus found
		Checked by Hillstone Network AntiVirus

[PATCH 2/2] drm/udl: Use iosys_map getter for virtual address

[oushixiong1025]

From: Shixiong Ou <oushixiong@kylinos.cn>

Replace direct access to map->vaddr with the new iosys_map_get_vaddr()
helper function. This properly uses the iosys_map abstraction layer
instead of directly accessing structure members.

Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>
---
 drivers/gpu/drm/udl/udl_modeset.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/udl/udl_modeset.c b/drivers/gpu/drm/udl/udl_modeset.c
index 289711035b67..06a3a4d149b9 100644
--- a/drivers/gpu/drm/udl/udl_modeset.c
+++ b/drivers/gpu/drm/udl/udl_modeset.c
@@ -207,12 +207,16 @@ static int udl_handle_damage(struct drm_framebuffer *fb,
 {
 	struct drm_device *dev = fb->dev;
 	struct udl_device *udl = to_udl(dev);
-	void *vaddr = map->vaddr; /* TODO: Use mapping abstraction properly */
+	void *vaddr;
 	int i, ret;
 	char *cmd;
 	struct urb *urb;
 	int log_bpp;
 
+	vaddr = iosys_map_get_vaddr(map);
+	if (!vaddr)
+		return -EFAULT;
+
 	ret = udl_log_cpp(fb->format->cpp[0]);
 	if (ret < 0)
 		return ret;
-- 
2.25.1


No virus found
		Checked by Hillstone Network AntiVirus

Re: [PATCH 2/2] drm/udl: Use iosys_map getter for virtual address

[Thomas Zimmermann]

Hi

Am 24.07.26 um 11:38 schrieb oushixiong1025@163.com:
> From: Shixiong Ou <oushixiong@kylinos.cn>
>
> Replace direct access to map->vaddr with the new iosys_map_get_vaddr()
> helper function. This properly uses the iosys_map abstraction layer
> instead of directly accessing structure members.
>
> Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>
> ---
>   drivers/gpu/drm/udl/udl_modeset.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/udl/udl_modeset.c b/drivers/gpu/drm/udl/udl_modeset.c
> index 289711035b67..06a3a4d149b9 100644
> --- a/drivers/gpu/drm/udl/udl_modeset.c
> +++ b/drivers/gpu/drm/udl/udl_modeset.c
> @@ -207,12 +207,16 @@ static int udl_handle_damage(struct drm_framebuffer *fb,
>   {
>   	struct drm_device *dev = fb->dev;
>   	struct udl_device *udl = to_udl(dev);
> -	void *vaddr = map->vaddr; /* TODO: Use mapping abstraction properly */
> +	void *vaddr;
>   	int i, ret;
>   	char *cmd;
>   	struct urb *urb;
>   	int log_bpp;
>   
> +	vaddr = iosys_map_get_vaddr(map);
> +	if (!vaddr)
> +		return -EFAULT;
> +

This doesn't work in practice because we don't handle the vmap_iomem 
correctly. You'll get NULL now, when before it was treated as a regular 
address.

The current type aliasing works until we have proper import handling of 
I/O-mem addresses.

Best regards
Thomas


>   	ret = udl_log_cpp(fb->format->cpp[0]);
>   	if (ret < 0)
>   		return ret;

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, (HRB 36809, AG Nürnberg)