Revision b90d72a6bfdb5e5c62cd223a8cdf4045bfbcb94d authored by Will Deacon on 12 January 2021, 22:18:55 UTC, committed by Catalin Marinas on 13 January 2021, 15:08:41 UTC
This reverts commit 367c820ef08082e68df8a3bc12e62393af21e4b5.

lockup_detector_init() makes heavy use of per-cpu variables and must be
called with preemption disabled. Usually, it's handled early during boot
in kernel_init_freeable(), before SMP has been initialised.

Since we do not know whether or not our PMU interrupt can be signalled
as an NMI until considerably later in the boot process, the Arm PMU
driver attempts to re-initialise the lockup detector off the back of a
device_initcall(). Unfortunately, this is called from preemptible
context and results in the following splat:

  | BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
  | caller is debug_smp_processor_id+0x20/0x2c
  | CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.10.0+ #276
  | Hardware name: linux,dummy-virt (DT)
  | Call trace:
  |   dump_backtrace+0x0/0x3c0
  |   show_stack+0x20/0x6c
  |   dump_stack+0x2f0/0x42c
  |   check_preemption_disabled+0x1cc/0x1dc
  |   debug_smp_processor_id+0x20/0x2c
  |   hardlockup_detector_event_create+0x34/0x18c
  |   hardlockup_detector_perf_init+0x2c/0x134
  |   watchdog_nmi_probe+0x18/0x24
  |   lockup_detector_init+0x44/0xa8
  |   armv8_pmu_driver_init+0x54/0x78
  |   do_one_initcall+0x184/0x43c
  |   kernel_init_freeable+0x368/0x380
  |   kernel_init+0x1c/0x1cc
  |   ret_from_fork+0x10/0x30

Rather than bodge this with raw_smp_processor_id() or randomly disabling
preemption, simply revert the culprit for now until we figure out how to
do this properly.

Reported-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Sumit Garg <sumit.garg@linaro.org>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20201221162249.3119-1-lecopzer.chen@mediatek.com
Link: https://lore.kernel.org/r/20210112221855.10666-1-will@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
1 parent df06824
Raw File
mmp_disp.h
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * linux/include/video/mmp_disp.h
 * Header file for Marvell MMP Display Controller
 *
 * Copyright (C) 2012 Marvell Technology Group Ltd.
 * Authors: Zhou Zhu <zzhu3@marvell.com>
 */

#ifndef _MMP_DISP_H_
#define _MMP_DISP_H_
#include <linux/kthread.h>

enum {
	PIXFMT_UYVY = 0,
	PIXFMT_VYUY,
	PIXFMT_YUYV,
	PIXFMT_YUV422P,
	PIXFMT_YVU422P,
	PIXFMT_YUV420P,
	PIXFMT_YVU420P,
	PIXFMT_RGB565 = 0x100,
	PIXFMT_BGR565,
	PIXFMT_RGB1555,
	PIXFMT_BGR1555,
	PIXFMT_RGB888PACK,
	PIXFMT_BGR888PACK,
	PIXFMT_RGB888UNPACK,
	PIXFMT_BGR888UNPACK,
	PIXFMT_RGBA888,
	PIXFMT_BGRA888,
	PIXFMT_RGB666, /* for output usage */
	PIXFMT_PSEUDOCOLOR = 0x200,
};

static inline int pixfmt_to_stride(int pix_fmt)
{
	switch (pix_fmt) {
	case PIXFMT_RGB565:
	case PIXFMT_BGR565:
	case PIXFMT_RGB1555:
	case PIXFMT_BGR1555:
	case PIXFMT_UYVY:
	case PIXFMT_VYUY:
	case PIXFMT_YUYV:
		return 2;
	case PIXFMT_RGB888UNPACK:
	case PIXFMT_BGR888UNPACK:
	case PIXFMT_RGBA888:
	case PIXFMT_BGRA888:
		return 4;
	case PIXFMT_RGB888PACK:
	case PIXFMT_BGR888PACK:
		return 3;
	case PIXFMT_YUV422P:
	case PIXFMT_YVU422P:
	case PIXFMT_YUV420P:
	case PIXFMT_YVU420P:
	case PIXFMT_PSEUDOCOLOR:
		return 1;
	default:
		return 0;
	}
}

/* parameters used by path/overlay */
/* overlay related para: win/addr */
struct mmp_win {
	/* position/size of window */
	u16	xsrc;
	u16	ysrc;
	u16	xdst;
	u16	ydst;
	u16	xpos;
	u16	ypos;
	u16	left_crop;
	u16	right_crop;
	u16	up_crop;
	u16	bottom_crop;
	int	pix_fmt;
	/*
	 * pitch[0]: graphics/video layer line length or y pitch
	 * pitch[1]/pitch[2]: video u/v pitch if non-zero
	 */
	u32	pitch[3];
};

struct mmp_addr {
	/* phys address */
	u32	phys[6];
};

/* path related para: mode */
struct mmp_mode {
	const char *name;
	u32 refresh;
	u32 xres;
	u32 yres;
	u32 left_margin;
	u32 right_margin;
	u32 upper_margin;
	u32 lower_margin;
	u32 hsync_len;
	u32 vsync_len;
	u32 hsync_invert;
	u32 vsync_invert;
	u32 invert_pixclock;
	u32 pixclock_freq;
	int pix_fmt_out;
};

/* main structures */
struct mmp_path;
struct mmp_overlay;
struct mmp_panel;

/* status types */
enum {
	MMP_OFF = 0,
	MMP_ON,
};

static inline const char *stat_name(int stat)
{
	switch (stat) {
	case MMP_OFF:
		return "OFF";
	case MMP_ON:
		return "ON";
	default:
		return "UNKNOWNSTAT";
	}
}

struct mmp_overlay_ops {
	/* should be provided by driver */
	void (*set_fetch)(struct mmp_overlay *overlay, int fetch_id);
	void (*set_onoff)(struct mmp_overlay *overlay, int status);
	void (*set_win)(struct mmp_overlay *overlay, struct mmp_win *win);
	int (*set_addr)(struct mmp_overlay *overlay, struct mmp_addr *addr);
};

/* overlay describes a z-order indexed slot in each path. */
struct mmp_overlay {
	int id;
	const char *name;
	struct mmp_path *path;

	/* overlay info: private data */
	int dmafetch_id;
	struct mmp_addr addr;
	struct mmp_win win;

	/* state */
	int open_count;
	int status;
	struct mutex access_ok;

	struct mmp_overlay_ops *ops;
};

/* panel type */
enum {
	PANELTYPE_ACTIVE = 0,
	PANELTYPE_SMART,
	PANELTYPE_TV,
	PANELTYPE_DSI_CMD,
	PANELTYPE_DSI_VIDEO,
};

struct mmp_panel {
	/* use node to register to list */
	struct list_head node;
	const char *name;
	/* path name used to connect to proper path configed */
	const char *plat_path_name;
	struct device *dev;
	int panel_type;
	void *plat_data;
	int (*get_modelist)(struct mmp_panel *panel,
			struct mmp_mode **modelist);
	void (*set_mode)(struct mmp_panel *panel,
			struct mmp_mode *mode);
	void (*set_onoff)(struct mmp_panel *panel,
			int status);
};

struct mmp_path_ops {
	int (*check_status)(struct mmp_path *path);
	struct mmp_overlay *(*get_overlay)(struct mmp_path *path,
			int overlay_id);
	int (*get_modelist)(struct mmp_path *path,
			struct mmp_mode **modelist);

	/* follow ops should be provided by driver */
	void (*set_mode)(struct mmp_path *path, struct mmp_mode *mode);
	void (*set_onoff)(struct mmp_path *path, int status);
	/* todo: add query */
};

/* path output types */
enum {
	PATH_OUT_PARALLEL,
	PATH_OUT_DSI,
	PATH_OUT_HDMI,
};

/* path is main part of mmp-disp */
struct mmp_path {
	/* use node to register to list */
	struct list_head node;

	/* init data */
	struct device *dev;

	int id;
	const char *name;
	int output_type;
	struct mmp_panel *panel;
	void *plat_data;

	/* dynamic use */
	struct mmp_mode mode;

	/* state */
	int open_count;
	int status;
	struct mutex access_ok;

	struct mmp_path_ops ops;

	/* layers */
	int overlay_num;
	struct mmp_overlay overlays[];
};

extern struct mmp_path *mmp_get_path(const char *name);
static inline void mmp_path_set_mode(struct mmp_path *path,
		struct mmp_mode *mode)
{
	if (path)
		path->ops.set_mode(path, mode);
}
static inline void mmp_path_set_onoff(struct mmp_path *path, int status)
{
	if (path)
		path->ops.set_onoff(path, status);
}
static inline int mmp_path_get_modelist(struct mmp_path *path,
		struct mmp_mode **modelist)
{
	if (path)
		return path->ops.get_modelist(path, modelist);
	return 0;
}
static inline struct mmp_overlay *mmp_path_get_overlay(
		struct mmp_path *path, int overlay_id)
{
	if (path)
		return path->ops.get_overlay(path, overlay_id);
	return NULL;
}
static inline void mmp_overlay_set_fetch(struct mmp_overlay *overlay,
		int fetch_id)
{
	if (overlay)
		overlay->ops->set_fetch(overlay, fetch_id);
}
static inline void mmp_overlay_set_onoff(struct mmp_overlay *overlay,
		int status)
{
	if (overlay)
		overlay->ops->set_onoff(overlay, status);
}
static inline void mmp_overlay_set_win(struct mmp_overlay *overlay,
		struct mmp_win *win)
{
	if (overlay)
		overlay->ops->set_win(overlay, win);
}
static inline int mmp_overlay_set_addr(struct mmp_overlay *overlay,
		struct mmp_addr *addr)
{
	if (overlay)
		return overlay->ops->set_addr(overlay, addr);
	return 0;
}

/*
 * driver data is set from each detailed ctrl driver for path usage
 * it defined a common interface that plat driver need to implement
 */
struct mmp_path_info {
	/* driver data, set when registed*/
	const char *name;
	struct device *dev;
	int id;
	int output_type;
	int overlay_num;
	void (*set_mode)(struct mmp_path *path, struct mmp_mode *mode);
	void (*set_onoff)(struct mmp_path *path, int status);
	struct mmp_overlay_ops *overlay_ops;
	void *plat_data;
};

extern struct mmp_path *mmp_register_path(
		struct mmp_path_info *info);
extern void mmp_unregister_path(struct mmp_path *path);
extern void mmp_register_panel(struct mmp_panel *panel);
extern void mmp_unregister_panel(struct mmp_panel *panel);

/* defintions for platform data */
/* interface for buffer driver */
struct mmp_buffer_driver_mach_info {
	const char	*name;
	const char	*path_name;
	int	overlay_id;
	int	dmafetch_id;
	int	default_pixfmt;
};

/* interface for controllers driver */
struct mmp_mach_path_config {
	const char *name;
	int overlay_num;
	int output_type;
	u32 path_config;
	u32 link_config;
	u32 dsi_rbswap;
};

struct mmp_mach_plat_info {
	const char *name;
	const char *clk_name;
	int path_num;
	struct mmp_mach_path_config *paths;
};

/* interface for panel drivers */
struct mmp_mach_panel_info {
	const char *name;
	void (*plat_set_onoff)(int status);
	const char *plat_path_name;
};
#endif	/* _MMP_DISP_H_ */
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