linux_dsm_epyc7002/include/linux/devcoredump.h
Johannes Berg 833c95456a device coredump: add new device coredump class
Many devices run firmware and/or complex hardware, and most of that
can have bugs. When it misbehaves, however, it is often much harder
to debug than software running on the host.

Introduce a "device coredump" mechanism to allow dumping internal
device/firmware state through a generalized mechanism. As devices
are different and information needed can vary accordingly, this
doesn't prescribe a file format - it just provides mechanism to
get data to be able to capture it in a generalized way (e.g. in
distributions.)

The dumped data will be readable in sysfs in the virtual device's
data file under /sys/class/devcoredump/devcd*/. Writing to it will
free the data and remove the device, as does a 5-minute timeout.

Note that generalized capturing of such data may result in privacy
issues, so users generally need to be involved. In order to allow
certain users/system integrators/... to disable the feature at all,
introduce a Kconfig option to override the drivers that would like
to have the feature.

For now, this provides two ways of dumping data:
 1) with a vmalloc'ed area, that is then given to the subsystem
    and freed after retrieval or timeout
 2) with a generalized reader/free function method

We could/should add more options, e.g. a list of pages, since the
vmalloc area is very limited on some architectures.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-23 22:53:15 -07:00

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C

#ifndef __DEVCOREDUMP_H
#define __DEVCOREDUMP_H
#include <linux/device.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#ifdef CONFIG_DEV_COREDUMP
void dev_coredumpv(struct device *dev, const void *data, size_t datalen,
gfp_t gfp);
void dev_coredumpm(struct device *dev, struct module *owner,
const void *data, size_t datalen, gfp_t gfp,
ssize_t (*read)(char *buffer, loff_t offset, size_t count,
const void *data, size_t datalen),
void (*free)(const void *data));
#else
static inline void dev_coredumpv(struct device *dev, const void *data,
size_t datalen, gfp_t gfp)
{
vfree(data);
}
static inline void
dev_coredumpm(struct device *dev, struct module *owner,
const void *data, size_t datalen, gfp_t gfp,
ssize_t (*read)(char *buffer, loff_t offset, size_t count,
const void *data, size_t datalen),
void (*free)(const void *data))
{
free(data);
}
#endif /* CONFIG_DEV_COREDUMP */
#endif /* __DEVCOREDUMP_H */