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 --- include/linux/fb.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include/linux/fb.h') 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 From 8fd4bd22350784d5b2fe9274f6790ba353976415 Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Wed, 23 Jun 2010 12:56:12 -0700 Subject: vt/console: try harder to print output when panicing Jesse's initial patch commit said: "At panic time (i.e. when oops_in_progress is set) we should try a bit harder to update the screen and make sure output gets to the VT, since some drivers are capable of flipping back to it. So make sure we try to unblank and update the display if called from a panic context." I've enhanced this to add a flag to the vc that console layer can set to indicate they want this behaviour to occur. This also adds support to fbcon for that flag and adds an fb flag for drivers to indicate they want to use the support. It enables this for KMS drivers. Signed-off-by: Dave Airlie Signed-off-by: Jesse Barnes Acked-by: James Simmons Cc: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/char/vt.c | 13 +++++++++---- drivers/gpu/drm/i915/intel_fb.c | 4 +--- drivers/gpu/drm/nouveau/nouveau_fbcon.c | 1 + drivers/gpu/drm/radeon/radeon_fb.c | 2 +- drivers/video/console/fbcon.c | 4 +++- include/linux/console_struct.h | 1 + include/linux/fb.h | 4 ++++ include/linux/vt_kern.h | 7 +++++++ 8 files changed, 27 insertions(+), 9 deletions(-) (limited to 'include/linux/fb.h') diff --git a/drivers/char/vt.c b/drivers/char/vt.c index 34bfb056d7a6..82f64ac21191 100644 --- a/drivers/char/vt.c +++ b/drivers/char/vt.c @@ -705,7 +705,10 @@ void redraw_screen(struct vc_data *vc, int is_switch) update_attr(vc); clear_buffer_attributes(vc); } - if (update && vc->vc_mode != KD_GRAPHICS) + + /* Forcibly update if we're panicing */ + if ((update && vc->vc_mode != KD_GRAPHICS) || + vt_force_oops_output(vc)) do_update_region(vc, vc->vc_origin, vc->vc_screenbuf_size / 2); } set_cursor(vc); @@ -743,6 +746,7 @@ static void visual_init(struct vc_data *vc, int num, int init) vc->vc_hi_font_mask = 0; vc->vc_complement_mask = 0; vc->vc_can_do_color = 0; + vc->vc_panic_force_write = false; vc->vc_sw->con_init(vc, init); if (!vc->vc_complement_mask) vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800; @@ -2506,7 +2510,7 @@ static void vt_console_print(struct console *co, const char *b, unsigned count) goto quit; } - if (vc->vc_mode != KD_TEXT) + if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc)) goto quit; /* undraw cursor first */ @@ -3784,7 +3788,8 @@ void do_unblank_screen(int leaving_gfx) return; } vc = vc_cons[fg_console].d; - if (vc->vc_mode != KD_TEXT) + /* Try to unblank in oops case too */ + if (vc->vc_mode != KD_TEXT && !vt_force_oops_output(vc)) return; /* but leave console_blanked != 0 */ if (blankinterval) { @@ -3793,7 +3798,7 @@ void do_unblank_screen(int leaving_gfx) } console_blanked = 0; - if (vc->vc_sw->con_blank(vc, 0, leaving_gfx)) + if (vc->vc_sw->con_blank(vc, 0, leaving_gfx) || vt_force_oops_output(vc)) /* Low-level driver cannot restore -> do it ourselves */ update_screen(vc); if (console_blank_hook) diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c index 54acd8b534df..a79525f434a8 100644 --- a/drivers/gpu/drm/i915/intel_fb.c +++ b/drivers/gpu/drm/i915/intel_fb.c @@ -130,7 +130,7 @@ static int intelfb_create(struct intel_fbdev *ifbdev, strcpy(info->fix.id, "inteldrmfb"); - info->flags = FBINFO_DEFAULT; + info->flags = FBINFO_DEFAULT | FBINFO_CAN_FORCE_OUTPUT; info->fbops = &intelfb_ops; /* setup aperture base/size for vesafb takeover */ @@ -148,8 +148,6 @@ static int intelfb_create(struct intel_fbdev *ifbdev, info->fix.smem_start = dev->mode_config.fb_base + obj_priv->gtt_offset; info->fix.smem_len = size; - info->flags = FBINFO_DEFAULT; - info->screen_base = ioremap_wc(dev->agp->base + obj_priv->gtt_offset, size); if (!info->screen_base) { diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c index 2fb2444d2322..099f637264aa 100644 --- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c +++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c @@ -250,6 +250,7 @@ nouveau_fbcon_create(struct nouveau_fbdev *nfbdev, info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_COPYAREA | FBINFO_HWACCEL_FILLRECT | FBINFO_HWACCEL_IMAGEBLIT; + info->flags |= FBINFO_CAN_FORCE_OUTPUT; info->fbops = &nouveau_fbcon_ops; info->fix.smem_start = dev->mode_config.fb_base + nvbo->bo.offset - dev_priv->vm_vram_base; diff --git a/drivers/gpu/drm/radeon/radeon_fb.c b/drivers/gpu/drm/radeon/radeon_fb.c index dc1634bb0c11..dbf86962bdd1 100644 --- a/drivers/gpu/drm/radeon/radeon_fb.c +++ b/drivers/gpu/drm/radeon/radeon_fb.c @@ -224,7 +224,7 @@ static int radeonfb_create(struct radeon_fbdev *rfbdev, drm_fb_helper_fill_fix(info, fb->pitch, fb->depth); - info->flags = FBINFO_DEFAULT; + info->flags = FBINFO_DEFAULT | FBINFO_CAN_FORCE_OUTPUT; info->fbops = &radeonfb_ops; tmp = radeon_bo_gpu_offset(rbo) - rdev->mc.vram_start; diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c index 3b3f5749af92..26bf7cbfecc2 100644 --- a/drivers/video/console/fbcon.c +++ b/drivers/video/console/fbcon.c @@ -283,7 +283,8 @@ static inline int fbcon_is_inactive(struct vc_data *vc, struct fb_info *info) struct fbcon_ops *ops = info->fbcon_par; return (info->state != FBINFO_STATE_RUNNING || - vc->vc_mode != KD_TEXT || ops->graphics); + vc->vc_mode != KD_TEXT || ops->graphics) && + !vt_force_oops_output(vc); } static inline int get_color(struct vc_data *vc, struct fb_info *info, @@ -1073,6 +1074,7 @@ static void fbcon_init(struct vc_data *vc, int init) if (p->userfont) charcnt = FNTCHARCNT(p->fontdata); + vc->vc_panic_force_write = !!(info->flags & FBINFO_CAN_FORCE_OUTPUT); vc->vc_can_do_color = (fb_get_color_depth(&info->var, &info->fix)!=1); vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800; if (charcnt == 256) { diff --git a/include/linux/console_struct.h b/include/linux/console_struct.h index 38fe59dc89ae..d7d9acdccffb 100644 --- a/include/linux/console_struct.h +++ b/include/linux/console_struct.h @@ -105,6 +105,7 @@ struct vc_data { struct vc_data **vc_display_fg; /* [!] Ptr to var holding fg console for this display */ unsigned long vc_uni_pagedir; unsigned long *vc_uni_pagedir_loc; /* [!] Location of uni_pagedir variable for this console */ + bool vc_panic_force_write; /* when oops/panic this VC can accept forced output/blanking */ /* additional information is in vt_kern.h */ }; diff --git a/include/linux/fb.h b/include/linux/fb.h index 0c5659c41b01..f0268deca658 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -825,6 +825,10 @@ struct fb_tile_ops { */ #define FBINFO_BE_MATH 0x100000 +/* report to the VT layer that this fb driver can accept forced console + output like oopses */ +#define FBINFO_CAN_FORCE_OUTPUT 0x200000 + struct fb_info { int node; int flags; diff --git a/include/linux/vt_kern.h b/include/linux/vt_kern.h index 7f56db4a79f0..56cce345aa8d 100644 --- a/include/linux/vt_kern.h +++ b/include/linux/vt_kern.h @@ -100,6 +100,13 @@ extern int unbind_con_driver(const struct consw *csw, int first, int last, int deflt); int vty_init(const struct file_operations *console_fops); +static inline bool vt_force_oops_output(struct vc_data *vc) +{ + if (oops_in_progress && vc->vc_panic_force_write) + return true; + return false; +} + /* * vc_screen.c shares this temporary buffer with the console write code so that * we can easily avoid touching user space while holding the console spinlock. -- cgit v1.2.3