On Thu, Apr 6, 2017 at 4:37 PM, Oliver O'Halloran <[email protected]> wrote: > On Thu, Mar 30, 2017 at 10:28 AM, Matt Brown > <[email protected]> wrote: >> The HDAT data area is consumed by skiboot and turned into a device-tree. In >> some cases we would like to look directly at the HDAT. This is not possible >> through /dev/mem as it is reserved memory which is stopped by the /dev/mem >> filter. There are also other memory areas which are reserved but could be >> useful to view for debugging purposes. >> >> This patch adds sysfs nodes to allow specified memory areas to be viewed. >> sysfs nodes are created for each property in the device-tree under >> /ibm,opal/firmware/exports/, and adds them to /sys/firmware/opal/exports/ >> with root read-only permissions. >> >> Signed-off-by: Matt Brown <[email protected]>
Thanks. I took the version that mpe put in the powerpc tree. It is part of the 4.10.9-openpower1 kernel. https://github.com/open-power/op-build/pull/1016 Cheers, Joel >> --- >> Changelog >> v8 >> - fixed error handling >> - added dynamic allocation of attributes >> - using of_property_read_u64_array for reading attr vals >> - reordered vars >> - renaming vars >> --- >> arch/powerpc/platforms/powernv/opal.c | 81 >> +++++++++++++++++++++++++++++++++++ >> 1 file changed, 81 insertions(+) >> >> diff --git a/arch/powerpc/platforms/powernv/opal.c >> b/arch/powerpc/platforms/powernv/opal.c >> index 2822935..232f94e 100644 >> --- a/arch/powerpc/platforms/powernv/opal.c >> +++ b/arch/powerpc/platforms/powernv/opal.c >> @@ -604,6 +604,84 @@ static void opal_export_symmap(void) >> 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_tmp; >> + struct device_node *np; >> + struct property *prop; >> + struct kobject *kobj; >> + u64 vals[2]; >> + int rc, n; >> + >> + /* Create new 'exports' directory - /sys/firmware/opal/exports */ >> + kobj = kobject_create_and_add("exports", opal_kobj); >> + if (!kobj) { >> + pr_warn("kobject_create_and_add exports failed\n"); >> + return; >> + } >> + >> + np = of_find_node_by_path("/ibm,opal/firmware/exports"); >> + if (!np) >> + return; >> + >> + n = 0; >> + for (prop = np->properties; prop != NULL; prop = prop->next) >> + n++; >> + >> + if (n < 2) >> + goto cleanup; >> + >> + 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_tmp = kmalloc(sizeof(*attr_tmp), GFP_KERNEL); >> + >> + if (attr_tmp == NULL) { >> + pr_warn("Failed kmalloc for bin_attribute attr_tmp"); >> + continue; >> + } >> + >> + attr_tmp->attr.name = kstrdup(prop->name, GFP_KERNEL); >> + attr_tmp->attr.mode = 0400; >> + attr_tmp->read = export_attr_read; >> + attr_tmp->private = __va(vals[0]); >> + attr_tmp->size = vals[1]; >> + >> + if (attr_tmp->attr.name == NULL) { >> + pr_warn("Failed kstrdup for bin_attribute >> attr.name"); >> + kfree(attr_tmp); >> + continue; >> + } >> + rc = sysfs_create_bin_file(kobj, attr_tmp); >> + if (rc) >> + pr_warn("Error %d creating OPAL sysfs exports/%s >> file\n", >> + rc, prop->name); >> + } >> + >> +cleanup: >> + of_node_put(np); >> +} >> + >> static void __init opal_dump_region_init(void) >> { >> void *addr; >> @@ -742,6 +820,9 @@ static int __init opal_init(void) >> opal_msglog_sysfs_init(); >> } >> >> + /* Export all properties */ >> + opal_export_attrs(); >> + >> /* Initialize platform devices: IPMI backend, PRD & flash interface >> */ >> opal_pdev_init("ibm,opal-ipmi"); >> opal_pdev_init("ibm,opal-flash"); >> -- >> 2.9.3 >> > > Reviewed-by: Oliver O'Halloran <[email protected]>
