Merge branch 'kms-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb

* 'kms-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
  kgdb,docs: Update the kgdb docs to include kms
  drm_fb_helper: Preserve capability to use atomic kms
  i915: when kgdb is active display compression should be off
  drm/i915: use new fb debug hooks
  drm: add KGDB/KDB support
  fb: add hooks to handle KDB enter/exit
  kgdboc: Add call backs to allow kernel mode switching
  vt,console,kdb: automatically set kdb LINES variable
  vt,console,kdb: implement atomic console enter/leave functions

7 files changed, 301 insertions, 2 deletions

diff --git a/drivers/char/vt.c b/drivers/char/vt.c
index 7cdb6ee569cd..4a9eb3044e52 100644
--- a/drivers/char/vt.c
+++ b/drivers/char/vt.c
@@ -104,6 +104,7 @@
 #include <linux/io.h>
 #include <asm/system.h>
 #include <linux/uaccess.h>
+#include <linux/kdb.h>
 
 #define MAX_NR_CON_DRIVER 16
 
@@ -187,10 +188,15 @@ static DECLARE_WORK(console_work, console_callback);
  * fg_console is the current virtual console,
  * last_console is the last used one,
  * want_console is the console we want to switch to,
+ * saved_* variants are for save/restore around kernel debugger enter/leave
  */
 int fg_console;
 int last_console;
 int want_console = -1;
+int saved_fg_console;
+int saved_last_console;
+int saved_want_console;
+int saved_vc_mode;
 
 /*
  * For each existing display, we have a pointer to console currently visible
@@ -3414,6 +3420,78 @@ int con_is_bound(const struct consw *csw)
 EXPORT_SYMBOL(con_is_bound);
 
 /**
+ * con_debug_enter - prepare the console for the kernel debugger
+ * @sw: console driver
+ *
+ * Called when the console is taken over by the kernel debugger, this
+ * function needs to save the current console state, then put the console
+ * into a state suitable for the kernel debugger.
+ *
+ * RETURNS:
+ * Zero on success, nonzero if a failure occurred when trying to prepare
+ * the console for the debugger.
+ */
+int con_debug_enter(struct vc_data *vc)
+{
+	int ret = 0;
+
+	saved_fg_console = fg_console;
+	saved_last_console = last_console;
+	saved_want_console = want_console;
+	saved_vc_mode = vc->vc_mode;
+	vc->vc_mode = KD_TEXT;
+	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);
+
+/**
+ * con_debug_leave - restore console state
+ * @sw: console driver
+ *
+ * Restore the console state to what it was before the kernel debugger
+ * was invoked.
+ *
+ * RETURNS:
+ * Zero on success, nonzero if a failure occurred when trying to restore
+ * the console.
+ */
+int con_debug_leave(void)
+{
+	struct vc_data *vc;
+	int ret = 0;
+
+	fg_console = saved_fg_console;
+	last_console = saved_last_console;
+	want_console = saved_want_console;
+	vc_cons[fg_console].d->vc_mode = saved_vc_mode;
+
+	vc = vc_cons[fg_console].d;
+	if (vc->vc_sw->con_debug_leave)
+		ret = vc->vc_sw->con_debug_leave(vc);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(con_debug_leave);
+
+/**
  * register_con_driver - register console driver to console layer
  * @csw: console driver
  * @first: the first console to take over, minimum value is 0
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 719662034bbf..de82e201d682 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;
@@ -611,7 +685,7 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
 	struct drm_framebuffer *fb = fb_helper->fb;
 	int depth;
 
-	if (var->pixclock != 0)
+	if (var->pixclock != 0 || in_dbg_master())
 		return -EINVAL;
 
 	/* Need to resize the fb object !!! */
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 5e21b3119824..714bf539918b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -975,7 +975,10 @@ void
 intel_wait_for_vblank(struct drm_device *dev)
 {
 	/* Wait for 20ms, i.e. one cycle at 50hz. */
-	msleep(20);
+	if (in_dbg_master())
+		mdelay(20); /* The kernel debugger cannot call msleep() */
+	else
+		msleep(20);
 }
 
 /* Parameters have changed, update FBC info */
@@ -1248,6 +1251,10 @@ static void intel_update_fbc(struct drm_crtc *crtc,
 		goto out_disable;
 	}
 
+	/* If the kernel debugger is active, always disable compression */
+	if (in_dbg_master())
+		goto out_disable;
+
 	if (intel_fbc_enabled(dev)) {
 		/* We can re-enable it in this case, but need to update pitch */
 		if ((fb->pitch > dev_priv->cfb_pitch) ||
@@ -1314,6 +1321,98 @@ intel_pin_and_fence_fb_obj(struct drm_device *dev, struct drm_gem_object *obj)
 	return 0;
 }
 
+/* Assume fb object is pinned & idle & fenced and just update base pointers */
+static int
+intel_pipe_set_base_atomic(struct drm_crtc *crtc, struct drm_framebuffer *fb,
+			   int x, int y)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	struct intel_framebuffer *intel_fb;
+	struct drm_i915_gem_object *obj_priv;
+	struct drm_gem_object *obj;
+	int plane = intel_crtc->plane;
+	unsigned long Start, Offset;
+	int dspbase = (plane == 0 ? DSPAADDR : DSPBADDR);
+	int dspsurf = (plane == 0 ? DSPASURF : DSPBSURF);
+	int dspstride = (plane == 0) ? DSPASTRIDE : DSPBSTRIDE;
+	int dsptileoff = (plane == 0 ? DSPATILEOFF : DSPBTILEOFF);
+	int dspcntr_reg = (plane == 0) ? DSPACNTR : DSPBCNTR;
+	u32 dspcntr;
+
+	switch (plane) {
+	case 0:
+	case 1:
+		break;
+	default:
+		DRM_ERROR("Can't update plane %d in SAREA\n", plane);
+		return -EINVAL;
+	}
+
+	intel_fb = to_intel_framebuffer(fb);
+	obj = intel_fb->obj;
+	obj_priv = to_intel_bo(obj);
+
+	dspcntr = I915_READ(dspcntr_reg);
+	/* Mask out pixel format bits in case we change it */
+	dspcntr &= ~DISPPLANE_PIXFORMAT_MASK;
+	switch (fb->bits_per_pixel) {
+	case 8:
+		dspcntr |= DISPPLANE_8BPP;
+		break;
+	case 16:
+		if (fb->depth == 15)
+			dspcntr |= DISPPLANE_15_16BPP;
+		else
+			dspcntr |= DISPPLANE_16BPP;
+		break;
+	case 24:
+	case 32:
+		dspcntr |= DISPPLANE_32BPP_NO_ALPHA;
+		break;
+	default:
+		DRM_ERROR("Unknown color depth\n");
+		return -EINVAL;
+	}
+	if (IS_I965G(dev)) {
+		if (obj_priv->tiling_mode != I915_TILING_NONE)
+			dspcntr |= DISPPLANE_TILED;
+		else
+			dspcntr &= ~DISPPLANE_TILED;
+	}
+
+	if (IS_IRONLAKE(dev))
+		/* must disable */
+		dspcntr |= DISPPLANE_TRICKLE_FEED_DISABLE;
+
+	I915_WRITE(dspcntr_reg, dspcntr);
+
+	Start = obj_priv->gtt_offset;
+	Offset = y * fb->pitch + x * (fb->bits_per_pixel / 8);
+
+	DRM_DEBUG("Writing base %08lX %08lX %d %d\n", Start, Offset, x, y);
+	I915_WRITE(dspstride, fb->pitch);
+	if (IS_I965G(dev)) {
+		I915_WRITE(dspbase, Offset);
+		I915_READ(dspbase);
+		I915_WRITE(dspsurf, Start);
+		I915_READ(dspsurf);
+		I915_WRITE(dsptileoff, (y << 16) | x);
+	} else {
+		I915_WRITE(dspbase, Start + Offset);
+		I915_READ(dspbase);
+	}
+
+	if ((IS_I965G(dev) || plane == 0))
+		intel_update_fbc(crtc, &crtc->mode);
+
+	intel_wait_for_vblank(dev);
+	intel_increase_pllclock(crtc, true);
+
+	return 0;
+}
+
 static int
 intel_pipe_set_base(struct drm_crtc *crtc, int x, int y,
 		    struct drm_framebuffer *old_fb)
@@ -4814,6 +4913,7 @@ static const struct drm_crtc_helper_funcs intel_helper_funcs = {
 	.mode_fixup = intel_crtc_mode_fixup,
 	.mode_set = intel_crtc_mode_set,
 	.mode_set_base = intel_pipe_set_base,
+	.mode_set_base_atomic = intel_pipe_set_base_atomic,
 	.prepare = intel_crtc_prepare,
 	.commit = intel_crtc_commit,
 	.load_lut = intel_crtc_load_lut,
diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
index 3e18c9e7729b..54acd8b534df 100644
--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -61,6 +61,8 @@ static struct fb_ops intelfb_ops = {
 	.fb_pan_display = drm_fb_helper_pan_display,
 	.fb_blank = drm_fb_helper_blank,
 	.fb_setcmap = drm_fb_helper_setcmap,
+	.fb_debug_enter = drm_fb_helper_debug_enter,
+	.fb_debug_leave = drm_fb_helper_debug_leave,
 };
 
 static int intelfb_create(struct intel_fbdev *ifbdev,
diff --git a/drivers/serial/kgdboc.c b/drivers/serial/kgdboc.c
index a9a94ae72349..39f9a1adaa75 100644
--- a/drivers/serial/kgdboc.c
+++ b/drivers/serial/kgdboc.c
@@ -17,6 +17,7 @@
 #include <linux/kdb.h>
 #include <linux/tty.h>
 #include <linux/console.h>
+#include <linux/vt_kern.h>
 
 #define MAX_CONFIG_LEN		40
 
@@ -31,6 +32,7 @@ static struct kparam_string kps = {
 	.maxlen			= MAX_CONFIG_LEN,
 };
 
+static int kgdboc_use_kms;  /* 1 if we use kernel mode switching */
 static struct tty_driver	*kgdb_tty_driver;
 static int			kgdb_tty_line;
 
@@ -104,6 +106,12 @@ static int configure_kgdboc(void)
 	kgdboc_io_ops.is_console = 0;
 	kgdb_tty_driver = NULL;
 
+	kgdboc_use_kms = 0;
+	if (strncmp(cptr, "kms,", 4) == 0) {
+		cptr += 4;
+		kgdboc_use_kms = 1;
+	}
+
 	if (kgdboc_register_kbd(&cptr))
 		goto do_register;
 
@@ -201,8 +209,14 @@ static int param_set_kgdboc_var(const char *kmessage, struct kernel_param *kp)
 	return configure_kgdboc();
 }
 
+static int dbg_restore_graphics;
+
 static void kgdboc_pre_exp_handler(void)
 {
+	if (!dbg_restore_graphics && kgdboc_use_kms) {
+		dbg_restore_graphics = 1;
+		con_debug_enter(vc_cons[fg_console].d);
+	}
 	/* Increment the module count when the debugger is active */
 	if (!kgdb_connected)
 		try_module_get(THIS_MODULE);
@@ -213,6 +227,10 @@ static void kgdboc_post_exp_handler(void)
 	/* decrement the module count when the debugger detaches */
 	if (!kgdb_connected)
 		module_put(THIS_MODULE);
+	if (kgdboc_use_kms && dbg_restore_graphics) {
+		dbg_restore_graphics = 0;
+		con_debug_leave();
+	}
 }
 
 static struct kgdb_io kgdboc_io_ops = {
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;