From b45cfba4e9005d64d419718e7ff7f7cab44c1994 Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Thu, 5 Aug 2010 09:22:30 -0500 Subject: vt,console,kdb: implement atomic console enter/leave functions These functions allow the kernel debugger to save and restore the state of the system console. Signed-off-by: Jesse Barnes Signed-off-by: Jason Wessel CC: David Airlie CC: Andrew Morton --- include/linux/console.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include') diff --git a/include/linux/console.h b/include/linux/console.h index dcca5339ceb3..f76fc297322d 100644 --- a/include/linux/console.h +++ b/include/linux/console.h @@ -55,6 +55,16 @@ struct consw { void (*con_invert_region)(struct vc_data *, u16 *, int); u16 *(*con_screen_pos)(struct vc_data *, int); unsigned long (*con_getxy)(struct vc_data *, unsigned long, int *, int *); + /* + * Prepare the console for the debugger. This includes, but is not + * limited to, unblanking the console, loading an appropriate + * palette, and allowing debugger generated output. + */ + int (*con_debug_enter)(struct vc_data *); + /* + * Restore the console to its pre-debug state as closely as possible. + */ + int (*con_debug_leave)(struct vc_data *); }; extern const struct consw *conswitchp; @@ -69,6 +79,9 @@ int register_con_driver(const struct consw *csw, int first, int last); int unregister_con_driver(const struct consw *csw); int take_over_console(const struct consw *sw, int first, int last, int deflt); void give_up_console(const struct consw *sw); +int con_debug_enter(struct vc_data *vc); +int con_debug_leave(void); + /* scroll */ #define SM_UP (1) #define SM_DOWN (2) -- cgit v1.2.3-70-g09d2 From 81d4450732c68aa728f2c86c0c2993c6cfc3d032 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Thu, 5 Aug 2010 09:22:30 -0500 Subject: vt,console,kdb: automatically set kdb LINES variable The kernel console interface stores the number of lines it is configured to use. The kdb debugger can greatly benefit by knowing how many lines there are on the console for the pager functionality without having the end user compile in the setting or have to repeatedly change it at run time. Signed-off-by: Jason Wessel Signed-off-by: Jesse Barnes CC: David Airlie CC: Andrew Morton --- drivers/char/vt.c | 17 +++++++++++++++++ include/linux/kdb.h | 4 ++++ kernel/debug/kdb/kdb_private.h | 2 -- 3 files changed, 21 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/drivers/char/vt.c b/drivers/char/vt.c index 117ce99115dc..4a9eb3044e52 100644 --- a/drivers/char/vt.c +++ b/drivers/char/vt.c @@ -104,6 +104,7 @@ #include #include #include +#include #define MAX_NR_CON_DRIVER 16 @@ -3442,6 +3443,22 @@ int con_debug_enter(struct vc_data *vc) console_blanked = 0; if (vc->vc_sw->con_debug_enter) ret = vc->vc_sw->con_debug_enter(vc); +#ifdef CONFIG_KGDB_KDB + /* Set the initial LINES variable if it is not already set */ + if (vc->vc_rows < 999) { + int linecount; + char lns[4]; + const char *setargs[3] = { + "set", + "LINES", + lns, + }; + if (kdbgetintenv(setargs[0], &linecount)) { + snprintf(lns, 4, "%i", vc->vc_rows); + kdb_set(2, setargs); + } + } +#endif /* CONFIG_KGDB_KDB */ return ret; } EXPORT_SYMBOL_GPL(con_debug_enter); diff --git a/include/linux/kdb.h b/include/linux/kdb.h index ccb2b3ec0fe8..ea6e5244ed3f 100644 --- a/include/linux/kdb.h +++ b/include/linux/kdb.h @@ -114,4 +114,8 @@ enum { KDB_INIT_EARLY, KDB_INIT_FULL, }; + +extern int kdbgetintenv(const char *, int *); +extern int kdb_set(int, const char **); + #endif /* !_KDB_H */ diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h index 97d3ba69775d..c438f545a321 100644 --- a/kernel/debug/kdb/kdb_private.h +++ b/kernel/debug/kdb/kdb_private.h @@ -144,9 +144,7 @@ extern int kdb_getword(unsigned long *, unsigned long, size_t); extern int kdb_putword(unsigned long, unsigned long, size_t); extern int kdbgetularg(const char *, unsigned long *); -extern int kdb_set(int, const char **); extern char *kdbgetenv(const char *); -extern int kdbgetintenv(const char *, int *); extern int kdbgetaddrarg(int, const char **, int*, unsigned long *, long *, char **); extern int kdbgetsymval(const char *, kdb_symtab_t *); -- cgit v1.2.3-70-g09d2 From d219adc1228a3887486b58a430e736b0831f192c Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Mon, 2 Aug 2010 12:05:41 -0700 Subject: 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 Signed-off-by: Jason Wessel --- drivers/video/console/fbcon.c | 26 ++++++++++++++++++++++++++ drivers/video/console/fbcon.h | 1 + include/linux/fb.h | 13 +++++++++++++ 3 files changed, 40 insertions(+) (limited to 'include') diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c index b0a3fa00706d..3b3f5749af92 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 89a346880ec0..6bd2e0c7f209 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 e7445df44d6c..0c5659c41b01 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -3,6 +3,9 @@ #include #include +#ifdef __KERNEL__ +#include +#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 -- cgit v1.2.3-70-g09d2 From 1a7aba7f4e45014c5a4741164b1ecb4ffe616fb7 Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Thu, 5 Aug 2010 09:22:31 -0500 Subject: drm: add KGDB/KDB support Implement the callbacks for KDB entry/exit via the drm helpers. Signed-off-by: Jesse Barnes Signed-off-by: Jason Wessel --- drivers/gpu/drm/drm_fb_helper.c | 74 +++++++++++++++++++++++++++++++++++++++++ include/drm/drm_crtc_helper.h | 2 ++ include/drm/drm_fb_helper.h | 5 +++ 3 files changed, 81 insertions(+) (limited to 'include') diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 719662034bbf..6245add3768a 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -241,6 +241,80 @@ static int drm_fb_helper_parse_command_line(struct drm_fb_helper *fb_helper) return 0; } +int drm_fb_helper_debug_enter(struct fb_info *info) +{ + struct drm_fb_helper *helper = info->par; + struct drm_crtc_helper_funcs *funcs; + int i; + + if (list_empty(&kernel_fb_helper_list)) + return false; + + list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) { + for (i = 0; i < helper->crtc_count; i++) { + struct drm_mode_set *mode_set = + &helper->crtc_info[i].mode_set; + + if (!mode_set->crtc->enabled) + continue; + + funcs = mode_set->crtc->helper_private; + funcs->mode_set_base_atomic(mode_set->crtc, + mode_set->fb, + mode_set->x, + mode_set->y); + + } + } + + return 0; +} +EXPORT_SYMBOL(drm_fb_helper_debug_enter); + +/* Find the real fb for a given fb helper CRTC */ +static struct drm_framebuffer *drm_mode_config_fb(struct drm_crtc *crtc) +{ + struct drm_device *dev = crtc->dev; + struct drm_crtc *c; + + list_for_each_entry(c, &dev->mode_config.crtc_list, head) { + if (crtc->base.id == c->base.id) + return c->fb; + } + + return NULL; +} + +int drm_fb_helper_debug_leave(struct fb_info *info) +{ + struct drm_fb_helper *helper = info->par; + struct drm_crtc *crtc; + struct drm_crtc_helper_funcs *funcs; + struct drm_framebuffer *fb; + int i; + + for (i = 0; i < helper->crtc_count; i++) { + struct drm_mode_set *mode_set = &helper->crtc_info[i].mode_set; + crtc = mode_set->crtc; + funcs = crtc->helper_private; + fb = drm_mode_config_fb(crtc); + + if (!crtc->enabled) + continue; + + if (!fb) { + DRM_ERROR("no fb to restore??\n"); + continue; + } + + funcs->mode_set_base_atomic(mode_set->crtc, fb, crtc->x, + crtc->y); + } + + return 0; +} +EXPORT_SYMBOL(drm_fb_helper_debug_leave); + bool drm_fb_helper_force_kernel_mode(void) { int i = 0; diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h index 1121f7799c6f..10f7d03e58a9 100644 --- a/include/drm/drm_crtc_helper.h +++ b/include/drm/drm_crtc_helper.h @@ -60,6 +60,8 @@ struct drm_crtc_helper_funcs { /* Move the crtc on the current fb to the given position *optional* */ int (*mode_set_base)(struct drm_crtc *crtc, int x, int y, struct drm_framebuffer *old_fb); + int (*mode_set_base_atomic)(struct drm_crtc *crtc, + struct drm_framebuffer *fb, int x, int y); /* reload the current crtc LUT */ void (*load_lut)(struct drm_crtc *crtc); diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h index f0a6afc47e76..f22e7fe4b6db 100644 --- a/include/drm/drm_fb_helper.h +++ b/include/drm/drm_fb_helper.h @@ -32,6 +32,8 @@ struct drm_fb_helper; +#include + struct drm_fb_helper_crtc { uint32_t crtc_id; struct drm_mode_set mode_set; @@ -78,6 +80,7 @@ struct drm_fb_helper_connector { struct drm_fb_helper { struct drm_framebuffer *fb; + struct drm_framebuffer *saved_fb; struct drm_device *dev; struct drm_display_mode *mode; int crtc_count; @@ -126,5 +129,7 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info); bool drm_fb_helper_hotplug_event(struct drm_fb_helper *fb_helper); bool drm_fb_helper_initial_config(struct drm_fb_helper *fb_helper, int bpp_sel); int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper); +int drm_fb_helper_debug_enter(struct fb_info *info); +int drm_fb_helper_debug_leave(struct fb_info *info); #endif -- cgit v1.2.3-70-g09d2