/* atmapi.h - ATM API user space/kernel compatibility */
/* Written 1999,2000 by Werner Almesberger, EPFL ICA */
#ifndef _LINUX_ATMAPI_H
#define _LINUX_ATMAPI_H
#if defined(__sparc__) || defined(__ia64__)
/* such alignment is not required on 32 bit sparcs, but we can't
figure that we are on a sparc64 while compiling user-space programs. */
#define __ATM_API_ALIGN __attribute__((aligned(8)))
#else
#define __ATM_API_ALIGN
#endif
/*
* Opaque type for kernel pointers. Note that _ is never accessed. We need
* the struct in order hide the array, so that we can make simple assignments
* instead of being forced to use memcpy. It also improves error reporting for
* code that still assumes that we're passing unsigned longs.
*
* Convention: NULL pointers are passed as a field of all zeroes.
*/
typedef struct { unsigned char _[8]; } __ATM_API_ALIGN atm_kptr_t;
#endif
Erik reported that on a preproduction hardware a CMCI storm triggers the
BUG_ON in add_timer_on(). The reason is that the per CPU MCE timer is
started by the CMCI logic before the MCE CPU hotplug callback starts the
timer with add_timer_on(). So the timer is already queued which triggers
the BUG.
Using add_timer_on() is pretty pointless in this code because the timer is
strictlty per CPU, initialized as pinned and all operations which arm the
timer happen on the CPU to which the timer belongs.
Simplify the whole machinery by using mod_timer() instead of add_timer_on()
which avoids the problem because mod_timer() can handle already queued
timers. Use __start_timer() everywhere so the earliest armed expiry time is
preserved.
Reported-by: Erik Veijola <erik.veijola@intel.com>
Tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701310936080.3457@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>