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>
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cvisionppc.h
/*
* Phase5 CybervisionPPC (TVP4020) definitions for the Permedia2 framebuffer
* driver.
*
* Copyright (c) 1998-1999 Ilario Nardinocchi (nardinoc@CS.UniBO.IT)
* --------------------------------------------------------------------------
* $Id: cvisionppc.h,v 1.8 1999/01/28 13:18:07 illo Exp $
* --------------------------------------------------------------------------
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*/
#ifndef CVISIONPPC_H
#define CVISIONPPC_H
#ifndef PM2FB_H
#include "pm2fb.h"
#endif
struct cvppc_par {
unsigned char* pci_config;
unsigned char* pci_bridge;
u32 user_flags;
};
#define CSPPC_PCI_BRIDGE 0xfffe0000
#define CSPPC_BRIDGE_ENDIAN 0x0000
#define CSPPC_BRIDGE_INT 0x0010
#define CVPPC_PCI_CONFIG 0xfffc0000
#define CVPPC_ROM_ADDRESS 0xe2000001
#define CVPPC_REGS_REGION 0xef000000
#define CVPPC_FB_APERTURE_ONE 0xe0000000
#define CVPPC_FB_APERTURE_TWO 0xe1000000
#define CVPPC_FB_SIZE 0x00800000
#define CVPPC_MEM_CONFIG_OLD 0xed61fcaa /* FIXME Fujitsu?? */
#define CVPPC_MEM_CONFIG_NEW 0xed41c532 /* FIXME USA?? */
#define CVPPC_MEMCLOCK 83000 /* in KHz */
/* CVPPC_BRIDGE_ENDIAN */
#define CSPPCF_BRIDGE_BIG_ENDIAN 0x02
/* CVPPC_BRIDGE_INT */
#define CSPPCF_BRIDGE_ACTIVE_INT2 0x01
#endif /* CVISIONPPC_H */
/*****************************************************************************
* That's all folks!
*****************************************************************************/
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