1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Ultravisor high level interfaces 4 * 5 * Copyright 2019, IBM Corporation. 6 * 7 */ 8 #include <linux/init.h> 9 #include <linux/printk.h> 10 #include <linux/of_fdt.h> 11 #include <linux/of.h> 12 13 #include <asm/ultravisor.h> 14 #include <asm/firmware.h> 15 #include <asm/machdep.h> 16 17 #include "powernv.h" 18 19 static struct kobject *ultravisor_kobj; 20 21 int __init early_init_dt_scan_ultravisor(unsigned long node, const char *uname, 22 int depth, void *data) 23 { 24 if (!of_flat_dt_is_compatible(node, "ibm,ultravisor")) 25 return 0; 26 27 powerpc_firmware_features |= FW_FEATURE_ULTRAVISOR; 28 pr_debug("Ultravisor detected!\n"); 29 return 1; 30 } 31 32 static struct memcons *uv_memcons; 33 34 static ssize_t uv_msglog_read(struct file *file, struct kobject *kobj, 35 struct bin_attribute *bin_attr, char *to, 36 loff_t pos, size_t count) 37 { 38 return memcons_copy(uv_memcons, to, pos, count); 39 } 40 41 static struct bin_attribute uv_msglog_attr = { 42 .attr = {.name = "msglog", .mode = 0400}, 43 .read = uv_msglog_read 44 }; 45 46 static int __init uv_init(void) 47 { 48 struct device_node *node; 49 50 if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR)) 51 return 0; 52 53 node = of_find_compatible_node(NULL, NULL, "ibm,uv-firmware"); 54 if (!node) 55 return -ENODEV; 56 57 uv_memcons = memcons_init(node, "memcons"); 58 of_node_put(node); 59 if (!uv_memcons) 60 return -ENOENT; 61 62 uv_msglog_attr.size = memcons_get_size(uv_memcons); 63 64 ultravisor_kobj = kobject_create_and_add("ultravisor", firmware_kobj); 65 if (!ultravisor_kobj) 66 return -ENOMEM; 67 68 return sysfs_create_bin_file(ultravisor_kobj, &uv_msglog_attr); 69 } 70 machine_subsys_initcall(powernv, uv_init); 71