Commit 11fe909d authored by Matt Brown's avatar Matt Brown Committed by Michael Ellerman

powerpc/powernv: Add OPAL exports attributes to sysfs

New versions of OPAL have a device node /ibm,opal/firmware/exports, each
property of which describes a range of memory in OPAL that Linux might
want to export to userspace for debugging.

This patch adds a sysfs file under 'opal/exports' for each property
found there, and makes it read-only by root.
Signed-off-by: default avatarMatt Brown <matthew.brown.dev@gmail.com>
[mpe: Drop counting of props, rename to attr, free on sysfs error, c'log]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 687da8fc
...@@ -595,6 +595,79 @@ static void opal_export_symmap(void) ...@@ -595,6 +595,79 @@ static void opal_export_symmap(void)
pr_warn("Error %d creating OPAL symbols file\n", rc); pr_warn("Error %d creating OPAL symbols file\n", rc);
} }
static ssize_t export_attr_read(struct file *fp, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf,
loff_t off, size_t count)
{
return memory_read_from_buffer(buf, count, &off, bin_attr->private,
bin_attr->size);
}
/*
* opal_export_attrs: creates a sysfs node for each property listed in
* the device-tree under /ibm,opal/firmware/exports/
* All new sysfs nodes are created under /opal/exports/.
* This allows for reserved memory regions (e.g. HDAT) to be read.
* The new sysfs nodes are only readable by root.
*/
static void opal_export_attrs(void)
{
struct bin_attribute *attr;
struct device_node *np;
struct property *prop;
struct kobject *kobj;
u64 vals[2];
int rc;
np = of_find_node_by_path("/ibm,opal/firmware/exports");
if (!np)
return;
/* Create new 'exports' directory - /sys/firmware/opal/exports */
kobj = kobject_create_and_add("exports", opal_kobj);
if (!kobj) {
pr_warn("kobject_create_and_add() of exports failed\n");
return;
}
for_each_property_of_node(np, prop) {
if (!strcmp(prop->name, "name") || !strcmp(prop->name, "phandle"))
continue;
if (of_property_read_u64_array(np, prop->name, &vals[0], 2))
continue;
attr = kmalloc(sizeof(*attr), GFP_KERNEL);
if (attr == NULL) {
pr_warn("Failed kmalloc for bin_attribute!");
continue;
}
attr->attr.name = kstrdup(prop->name, GFP_KERNEL);
attr->attr.mode = 0400;
attr->read = export_attr_read;
attr->private = __va(vals[0]);
attr->size = vals[1];
if (attr->attr.name == NULL) {
pr_warn("Failed kstrdup for bin_attribute attr.name");
kfree(attr);
continue;
}
rc = sysfs_create_bin_file(kobj, attr);
if (rc) {
pr_warn("Error %d creating OPAL sysfs exports/%s file\n",
rc, prop->name);
kfree(attr->attr.name);
kfree(attr);
}
}
of_node_put(np);
}
static void __init opal_dump_region_init(void) static void __init opal_dump_region_init(void)
{ {
void *addr; void *addr;
...@@ -733,6 +806,9 @@ static int __init opal_init(void) ...@@ -733,6 +806,9 @@ static int __init opal_init(void)
opal_msglog_sysfs_init(); opal_msglog_sysfs_init();
} }
/* Export all properties */
opal_export_attrs();
/* Initialize platform devices: IPMI backend, PRD & flash interface */ /* Initialize platform devices: IPMI backend, PRD & flash interface */
opal_pdev_init("ibm,opal-ipmi"); opal_pdev_init("ibm,opal-ipmi");
opal_pdev_init("ibm,opal-flash"); opal_pdev_init("ibm,opal-flash");
......
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