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powerpc/powernv: Move core and fadump_release_opalcore under new kobject

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The /sys/firmware/opal/core and /sys/kernel/fadump_release_opalcore
sysfs files are used to export and release the OPAL memory on PowerNV
platform. let's organize them into a new kobject under
/sys/firmware/opal/mpipl/ directory.

A symlink is added to maintain the backward compatibility for
/sys/firmware/opal/core sysfs file.

Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191211160910.21656-5-sourabhjain@linux.ibm.com
This commit is contained in:
Sourabh Jain 2019-12-11 21:39:08 +05:30 committed by Michael Ellerman
parent d418b19f34
commit 8852c07a88
3 changed files with 51 additions and 21 deletions
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2
Documentation/ABI/testing/sysfs-kernel-fadump_release_opalcore → Documentation/ABI/removed/sysfs-kernel-fadump_release_opalcore
View File

@ -1,3 +1,5 @@
This ABI is moved to /sys/firmware/opal/mpipl/release_core.
What: /sys/kernel/fadump_release_opalcore
Date: Sep 2019
Contact: linuxppc-dev@lists.ozlabs.org

15
Documentation/powerpc/firmware-assisted-dump.rst
View File

@ -112,13 +112,13 @@ to ensure that crash data is preserved to process later.
-- On OPAL based machines (PowerNV), if the kernel is build with
CONFIG_OPAL_CORE=y, OPAL memory at the time of crash is also
exported as /sys/firmware/opal/core file. This procfs file is
exported as /sys/firmware/opal/mpipl/core file. This procfs file is
helpful in debugging OPAL crashes with GDB. The kernel memory
used for exporting this procfs file can be released by echo'ing
'1' to /sys/kernel/fadump_release_opalcore node.
'1' to /sys/firmware/opal/mpipl/release_core node.
e.g.
# echo 1 > /sys/kernel/fadump_release_opalcore
# echo 1 > /sys/firmware/opal/mpipl/release_core
Implementation details:
-----------------------
@ -283,14 +283,17 @@ Here is the list of files under kernel sysfs:
enhanced to use this interface to release the memory reserved for
dump and continue without 2nd reboot.
/sys/kernel/fadump_release_opalcore
Note: /sys/kernel/fadump_release_opalcore sysfs has moved to
/sys/firmware/opal/mpipl/release_core
/sys/firmware/opal/mpipl/release_core
This file is available only on OPAL based machines when FADump is
active during capture kernel. This is used to release the memory
used by the kernel to export /sys/firmware/opal/core file. To
used by the kernel to export /sys/firmware/opal/mpipl/core file. To
release this memory, echo '1' to it:
echo 1 > /sys/kernel/fadump_release_opalcore
echo 1 > /sys/firmware/opal/mpipl/release_core
Here is the list of files under powerpc debugfs:
(Assuming debugfs is mounted on /sys/kernel/debug directory.)

55
arch/powerpc/platforms/powernv/opal-core.c
View File

@ -71,6 +71,7 @@ static LIST_HEAD(opalcore_list);
static struct opalcore_config *oc_conf;
static const struct opal_mpipl_fadump *opalc_metadata;
static const struct opal_mpipl_fadump *opalc_cpu_metadata;
struct kobject *mpipl_kobj;
/*
* Set crashing CPU's signal to SIGUSR1. if the kernel is triggered
@ -428,7 +429,7 @@ static void opalcore_cleanup(void)
return;
/* Remove OPAL core sysfs file */
sysfs_remove_bin_file(opal_kobj, &opal_core_attr);
sysfs_remove_bin_file(mpipl_kobj, &opal_core_attr);
oc_conf->ptload_phdr = NULL;
oc_conf->ptload_cnt = 0;
@ -563,9 +564,9 @@ error_out:
of_node_put(np);
}
static ssize_t fadump_release_opalcore_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count)
static ssize_t release_core_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count)
{
int input = -1;
@ -589,9 +590,23 @@ static ssize_t fadump_release_opalcore_store(struct kobject *kobj,
return count;
}
static struct kobj_attribute opalcore_rel_attr = __ATTR(fadump_release_opalcore,
0200, NULL,
fadump_release_opalcore_store);
static struct kobj_attribute opalcore_rel_attr = __ATTR_WO(release_core);
static struct attribute *mpipl_attr[] = {
&opalcore_rel_attr.attr,
NULL,
};
static struct bin_attribute *mpipl_bin_attr[] = {
&opal_core_attr,
NULL,
};
static struct attribute_group mpipl_group = {
.attrs = mpipl_attr,
.bin_attrs = mpipl_bin_attr,
};
static int __init opalcore_init(void)
{
@ -609,7 +624,7 @@ static int __init opalcore_init(void)
* then capture the dump.
*/
if (!(is_opalcore_usable())) {
pr_err("Failed to export /sys/firmware/opal/core\n");
pr_err("Failed to export /sys/firmware/opal/mpipl/core\n");
opalcore_cleanup();
return rc;
}
@ -617,18 +632,28 @@ static int __init opalcore_init(void)
/* Set OPAL core file size */
opal_core_attr.size = oc_conf->opalcore_size;
mpipl_kobj = kobject_create_and_add("mpipl", opal_kobj);
if (!mpipl_kobj) {
pr_err("unable to create mpipl kobject\n");
return -ENOMEM;
}
/* Export OPAL core sysfs file */
rc = sysfs_create_bin_file(opal_kobj, &opal_core_attr);
if (rc != 0) {
pr_err("Failed to export /sys/firmware/opal/core\n");
rc = sysfs_create_group(mpipl_kobj, &mpipl_group);
if (rc) {
pr_err("mpipl sysfs group creation failed (%d)", rc);
opalcore_cleanup();
return rc;
}
rc = sysfs_create_file(kernel_kobj, &opalcore_rel_attr.attr);
/* The /sys/firmware/opal/core is moved to /sys/firmware/opal/mpipl/
* directory, need to create symlink at old location to maintain
* backward compatibility.
*/
rc = compat_only_sysfs_link_entry_to_kobj(opal_kobj, mpipl_kobj,
"core", NULL);
if (rc) {
pr_warn("unable to create sysfs file fadump_release_opalcore (%d)\n",
rc);
pr_err("unable to create core symlink (%d)\n", rc);
return rc;
}
return 0;