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
19static struct kobject *ultravisor_kobj;
20
21int __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, name: "ibm,ultravisor"))
25 return 0;
26
27 powerpc_firmware_features |= FW_FEATURE_ULTRAVISOR;
28 pr_debug("Ultravisor detected!\n");
29 return 1;
30}
31
32static struct memcons *uv_memcons;
33
34static ssize_t uv_msglog_read(struct file *file, struct kobject *kobj,
35 const struct bin_attribute *bin_attr, char *to,
36 loff_t pos, size_t count)
37{
38 return memcons_copy(mc: uv_memcons, to, pos, count);
39}
40
41static struct bin_attribute uv_msglog_attr __ro_after_init = {
42 .attr = {.name = "msglog", .mode = 0400},
43 .read = uv_msglog_read
44};
45
46static 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, compat: "ibm,uv-firmware");
54 if (!node)
55 return -ENODEV;
56
57 uv_memcons = memcons_init(node, mc_prop_name: "memcons");
58 of_node_put(node);
59 if (!uv_memcons)
60 return -ENOENT;
61
62 uv_msglog_attr.size = memcons_get_size(mc: uv_memcons);
63
64 ultravisor_kobj = kobject_create_and_add(name: "ultravisor", parent: firmware_kobj);
65 if (!ultravisor_kobj)
66 return -ENOMEM;
67
68 return sysfs_create_bin_file(kobj: ultravisor_kobj, attr: &uv_msglog_attr);
69}
70machine_subsys_initcall(powernv, uv_init);
71

source code of linux/arch/powerpc/platforms/powernv/ultravisor.c