On Fri, Dec 06, 2019 at 05:54:34PM +0530, Sourabh Jain wrote: > Add a sys interface to allow querying the memory reserved by FADump for > saving the crash dump. > > Also added Documentation/ABI for the new sysfs file. > > Signed-off-by: Sourabh Jain <sourabhjain@xxxxxxxxxxxxx> > --- > Documentation/ABI/testing/sysfs-kernel-fadump | 7 +++++++ > Documentation/powerpc/firmware-assisted-dump.rst | 5 +++++ > arch/powerpc/kernel/fadump.c | 15 +++++++++++++++ > 3 files changed, 27 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-kernel-fadump b/Documentation/ABI/testing/sysfs-kernel-fadump > index 5d988b919e81..8f7a64a81783 100644 > --- a/Documentation/ABI/testing/sysfs-kernel-fadump > +++ b/Documentation/ABI/testing/sysfs-kernel-fadump > @@ -31,3 +31,10 @@ Description: write only > the system is booted to capture the vmcore using FADump. > It is used to release the memory reserved by FADump to > save the crash dump. > + > +What: /sys/kernel/fadump/mem_reserved > +Date: Dec 2019 > +Contact: linuxppc-dev@xxxxxxxxxxxxxxxx > +Description: read only > + Provide information about the amount of memory reserved by > + FADump to save the crash dump in bytes. > diff --git a/Documentation/powerpc/firmware-assisted-dump.rst b/Documentation/powerpc/firmware-assisted-dump.rst > index 365c10209ef3..04993eaf3113 100644 > --- a/Documentation/powerpc/firmware-assisted-dump.rst > +++ b/Documentation/powerpc/firmware-assisted-dump.rst > @@ -268,6 +268,11 @@ Here is the list of files under kernel sysfs: > be handled and vmcore will not be captured. This interface can be > easily integrated with kdump service start/stop. > > + /sys/kernel/fadump/mem_reserved > + > + This is used to display the memory reserved by FADump for saving the > + crash dump. > + > /sys/kernel/fadump_release_mem > This file is available only when FADump is active during > second kernel. This is used to release the reserved memory > diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c > index 41a3cda81791..b2af51b7c750 100644 > --- a/arch/powerpc/kernel/fadump.c > +++ b/arch/powerpc/kernel/fadump.c > @@ -1357,6 +1357,13 @@ static ssize_t fadump_enabled_show(struct kobject *kobj, > return sprintf(buf, "%d\n", fw_dump.fadump_enabled); > } > > +static ssize_t fadump_mem_reserved_show(struct kobject *kobj, > + struct kobj_attribute *attr, > + char *buf) > +{ > + return sprintf(buf, "%ld\n", fw_dump.reserve_dump_area_size); > +} > + > static ssize_t fadump_register_show(struct kobject *kobj, > struct kobj_attribute *attr, > char *buf) > @@ -1430,6 +1437,10 @@ static struct kobj_attribute enable_attr = __ATTR(enabled, > static struct kobj_attribute register_attr = __ATTR(registered, > 0644, fadump_register_show, > fadump_register_store); > +static struct kobj_attribute mem_reserved_attr = __ATTR(mem_reserved, > + 0444, fadump_mem_reserved_show, > + NULL); __ATTRI_RO()? > + > > DEFINE_SHOW_ATTRIBUTE(fadump_region); > > @@ -1464,6 +1475,10 @@ static void fadump_init_files(void) > pr_err("unable to create release_mem sysfs file (%d)\n", > rc); > } > + rc = sysfs_create_file(fadump_kobj, &mem_reserved_attr.attr); > + if (rc) > + pr_err("unable to create mem_reserved sysfs file (%d)\n", > + rc); Again, put it in an attribute group, that would have only required one line, and not this mess of not cleaning up if something went wrong. thanks, greg k-h