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authorJesse Barnes <jbarnes@virtuousgeek.org>2010-08-02 12:05:41 -0700
committerJason Wessel <jason.wessel@windriver.com>2010-08-05 09:22:31 -0500
commitd219adc1228a3887486b58a430e736b0831f192c (patch)
treea734e48a573774201ab8c6c06ff6eb6de60648f1
parent408a4be1f8cbee511895ee07da2a007a5a24303f (diff)
fb: add hooks to handle KDB enter/exit
Add fb ops to handle enter/exit of the kernel debugger. If present, the fb core will register them with KGDB and they'll be called when the debugger is entered and exited. The new functions are responsible for switching to an appropriate debug framebuffer and restoring the interrupted state at exit time. Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
-rw-r--r--drivers/video/console/fbcon.c26
-rw-r--r--drivers/video/console/fbcon.h1
-rw-r--r--include/linux/fb.h13
3 files changed, 40 insertions, 0 deletions
diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index b0a3fa00706..3b3f5749af9 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -2342,6 +2342,30 @@ static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch)
return 0;
}
+static int fbcon_debug_enter(struct vc_data *vc)
+{
+ struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
+ struct fbcon_ops *ops = info->fbcon_par;
+
+ ops->save_graphics = ops->graphics;
+ ops->graphics = 0;
+ if (info->fbops->fb_debug_enter)
+ info->fbops->fb_debug_enter(info);
+ fbcon_set_palette(vc, color_table);
+ return 0;
+}
+
+static int fbcon_debug_leave(struct vc_data *vc)
+{
+ struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
+ struct fbcon_ops *ops = info->fbcon_par;
+
+ ops->graphics = ops->save_graphics;
+ if (info->fbops->fb_debug_leave)
+ info->fbops->fb_debug_leave(info);
+ return 0;
+}
+
static int fbcon_get_font(struct vc_data *vc, struct console_font *font)
{
u8 *fontdata = vc->vc_font.data;
@@ -3276,6 +3300,8 @@ static const struct consw fb_con = {
.con_screen_pos = fbcon_screen_pos,
.con_getxy = fbcon_getxy,
.con_resize = fbcon_resize,
+ .con_debug_enter = fbcon_debug_enter,
+ .con_debug_leave = fbcon_debug_leave,
};
static struct notifier_block fbcon_event_notifier = {
diff --git a/drivers/video/console/fbcon.h b/drivers/video/console/fbcon.h
index 89a346880ec..6bd2e0c7f20 100644
--- a/drivers/video/console/fbcon.h
+++ b/drivers/video/console/fbcon.h
@@ -74,6 +74,7 @@ struct fbcon_ops {
int cursor_reset;
int blank_state;
int graphics;
+ int save_graphics; /* for debug enter/leave */
int flags;
int rotate;
int cur_rotate;
diff --git a/include/linux/fb.h b/include/linux/fb.h
index e7445df44d6..0c5659c41b0 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -3,6 +3,9 @@
#include <linux/types.h>
#include <linux/i2c.h>
+#ifdef __KERNEL__
+#include <linux/kgdb.h>
+#endif /* __KERNEL__ */
/* Definitions of frame buffers */
@@ -607,6 +610,12 @@ struct fb_deferred_io {
* LOCKING NOTE: those functions must _ALL_ be called with the console
* semaphore held, this is the only suitable locking mechanism we have
* in 2.6. Some may be called at interrupt time at this point though.
+ *
+ * The exception to this is the debug related hooks. Putting the fb
+ * into a debug state (e.g. flipping to the kernel console) and restoring
+ * it must be done in a lock-free manner, so low level drivers should
+ * keep track of the initial console (if applicable) and may need to
+ * perform direct, unlocked hardware writes in these hooks.
*/
struct fb_ops {
@@ -676,6 +685,10 @@ struct fb_ops {
/* teardown any resources to do with this framebuffer */
void (*fb_destroy)(struct fb_info *info);
+
+ /* called at KDB enter and leave time to prepare the console */
+ int (*fb_debug_enter)(struct fb_info *info);
+ int (*fb_debug_leave)(struct fb_info *info);
};
#ifdef CONFIG_FB_TILEBLITTING