On Tue, May 19, 2020 at 02:15:30PM -0700, Jakub Kicinski wrote: > Add infra for creating devlink instances for a device to report Thanks for doing this series as a PoC, counter to the module_firmware_crash() which I proposed to taint the kernel with a firmware crash flag to the kernel and module. For those not famliar about devlink: https://lwn.net/Articles/677967/ https://www.kernel.org/doc/html/latest/networking/devlink/index.html The github page also is now 404 as Jiri merged that stuff into iproute2: git://git.kernel.org/pub/scm/network/iproute2/iproute2.git > fw crashes. This patch expects the devlink instance to be registered > at probe time. I belive to be the cleanest. We can also add a devm > version of the helpers, so that we don't have to do the clean up. > Or we can go even further and register the devlink instance only > once error has happened (for the first time, then we can just > find out if already registered by traversing the list like we > do here). > > With the patch applied and a sample driver converted we get: > > $ devlink dev > pci/0000:07:00.0 > > Then monitor for errors: > > $ devlink mon health > [health,status] pci/0000:07:00.0: > reporter fw > state error error 1 recover 0 > [health,status] pci/0000:07:00.0: > reporter fw > state error error 2 recover 0 > > These are the events I triggered on purpose. One can also inspect > the health of all devices capable of reporting fw errors: > > $ devlink health > pci/0000:07:00.0: > reporter fw > state error error 7 recover 0 > > Obviously drivers may upgrade to the full devlink health API > which includes state dump, state dump auto-collect and automatic > error recovery control. > > Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> > --- > include/linux/devlink.h | 11 +++ > net/core/Makefile | 2 +- > net/core/devlink_simple_fw_reporter.c | 101 ++++++++++++++++++++++++++ > 3 files changed, 113 insertions(+), 1 deletion(-) > create mode 100644 include/linux/devlink.h > create mode 100644 net/core/devlink_simple_fw_reporter.c > > diff --git a/include/linux/devlink.h b/include/linux/devlink.h > new file mode 100644 > index 000000000000..2b73987eefca > --- /dev/null > +++ b/include/linux/devlink.h > @@ -0,0 +1,11 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +#ifndef _LINUX_DEVLINK_H_ > +#define _LINUX_DEVLINK_H_ > + > +struct device; > + > +void devlink_simple_fw_reporter_prepare(struct device *dev); > +void devlink_simple_fw_reporter_cleanup(struct device *dev); > +void devlink_simple_fw_reporter_report_crash(struct device *dev); > + > +#endif > diff --git a/net/core/Makefile b/net/core/Makefile > index 3e2c378e5f31..6f1513781c17 100644 > --- a/net/core/Makefile > +++ b/net/core/Makefile > @@ -31,7 +31,7 @@ obj-$(CONFIG_LWTUNNEL_BPF) += lwt_bpf.o > obj-$(CONFIG_BPF_STREAM_PARSER) += sock_map.o > obj-$(CONFIG_DST_CACHE) += dst_cache.o > obj-$(CONFIG_HWBM) += hwbm.o > -obj-$(CONFIG_NET_DEVLINK) += devlink.o > +obj-$(CONFIG_NET_DEVLINK) += devlink.o devlink_simple_fw_reporter.o This was looking super sexy up to here. This is networking specific. We want something generic for *anything* that requests firmware. I'm afraid this won't work for something generic. I don't think its throw-away work though, the idea to provide a generic interface to dump firmware through netlink might be nice for networking, or other things. But I have a feeling we'll want something still more generic than this. So networking may want to be aware that a firmware crash happened as part of this network device health thing, but firmware crashing is a generic thing. I have now extended my patch set to include uvents and I am more set on that we need the taint now more than ever. Luis > obj-$(CONFIG_GRO_CELLS) += gro_cells.o > obj-$(CONFIG_FAILOVER) += failover.o > obj-$(CONFIG_BPF_SYSCALL) += bpf_sk_storage.o > diff --git a/net/core/devlink_simple_fw_reporter.c b/net/core/devlink_simple_fw_reporter.c > new file mode 100644 > index 000000000000..48dde9123c3c > --- /dev/null > +++ b/net/core/devlink_simple_fw_reporter.c > @@ -0,0 +1,101 @@ > +#include <linux/devlink.h> > +#include <linux/list.h> > +#include <linux/mutex.h> > +#include <net/devlink.h> > + > +struct devlink_simple_fw_reporter { > + struct list_head list; > + struct devlink_health_reporter *reporter; > +}; > + > + > +static LIST_HEAD(devlink_simple_fw_reporters); > +static DEFINE_MUTEX(devlink_simple_fw_reporters_mutex); > + > +static const struct devlink_health_reporter_ops simple_devlink_health = { > + .name = "fw", > +}; > + > +static const struct devlink_ops simple_devlink_ops = { > +}; > + > +static struct devlink_simple_fw_reporter * > +devlink_simple_fw_reporter_find_for_dev(struct device *dev) > +{ > + struct devlink_simple_fw_reporter *simple_devlink, *ret = NULL; > + struct devlink *devlink; > + > + mutex_lock(&devlink_simple_fw_reporters_mutex); > + list_for_each_entry(simple_devlink, &devlink_simple_fw_reporters, > + list) { > + devlink = priv_to_devlink(simple_devlink); > + if (devlink->dev == dev) { > + ret = simple_devlink; > + break; > + } > + } > + mutex_unlock(&devlink_simple_fw_reporters_mutex); > + > + return ret; > +} > + > +void devlink_simple_fw_reporter_report_crash(struct device *dev) > +{ > + struct devlink_simple_fw_reporter *simple_devlink; > + > + simple_devlink = devlink_simple_fw_reporter_find_for_dev(dev); > + if (!simple_devlink) > + return; > + > + devlink_health_report(simple_devlink->reporter, "firmware crash", NULL); > +} > +EXPORT_SYMBOL_GPL(devlink_simple_fw_reporter_report_crash); > + > +void devlink_simple_fw_reporter_prepare(struct device *dev) > +{ > + struct devlink_simple_fw_reporter *simple_devlink; > + struct devlink *devlink; > + > + devlink = devlink_alloc(&simple_devlink_ops, > + sizeof(struct devlink_simple_fw_reporter)); > + if (!devlink) > + return; > + > + if (devlink_register(devlink, dev)) > + goto err_free; > + > + simple_devlink = devlink_priv(devlink); > + simple_devlink->reporter = > + devlink_health_reporter_create(devlink, &simple_devlink_health, > + 0, NULL); > + if (IS_ERR(simple_devlink->reporter)) > + goto err_unregister; > + > + mutex_lock(&devlink_simple_fw_reporters_mutex); > + list_add_tail(&simple_devlink->list, &devlink_simple_fw_reporters); > + mutex_unlock(&devlink_simple_fw_reporters_mutex); > + > + return; > + > +err_unregister: > + devlink_unregister(devlink); > +err_free: > + devlink_free(devlink); > +} > +EXPORT_SYMBOL_GPL(devlink_simple_fw_reporter_prepare); > + > +void devlink_simple_fw_reporter_cleanup(struct device *dev) > +{ > + struct devlink_simple_fw_reporter *simple_devlink; > + struct devlink *devlink; > + > + simple_devlink = devlink_simple_fw_reporter_find_for_dev(dev); > + if (!simple_devlink) > + return; > + > + devlink = priv_to_devlink(simple_devlink); > + devlink_health_reporter_destroy(simple_devlink->reporter); > + devlink_unregister(devlink); > + devlink_free(devlink); > +} > +EXPORT_SYMBOL_GPL(devlink_simple_fw_reporter_cleanup); > -- > 2.25.4 >
