xref: /OK3568_Linux_fs/kernel/arch/powerpc/platforms/powernv/ultravisor.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Ultravisor high level interfaces
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * Copyright 2019, IBM Corporation.
6*4882a593Smuzhiyun  *
7*4882a593Smuzhiyun  */
8*4882a593Smuzhiyun #include <linux/init.h>
9*4882a593Smuzhiyun #include <linux/printk.h>
10*4882a593Smuzhiyun #include <linux/of_fdt.h>
11*4882a593Smuzhiyun #include <linux/of.h>
12*4882a593Smuzhiyun 
13*4882a593Smuzhiyun #include <asm/ultravisor.h>
14*4882a593Smuzhiyun #include <asm/firmware.h>
15*4882a593Smuzhiyun #include <asm/machdep.h>
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun #include "powernv.h"
18*4882a593Smuzhiyun 
19*4882a593Smuzhiyun static struct kobject *ultravisor_kobj;
20*4882a593Smuzhiyun 
early_init_dt_scan_ultravisor(unsigned long node,const char * uname,int depth,void * data)21*4882a593Smuzhiyun int __init early_init_dt_scan_ultravisor(unsigned long node, const char *uname,
22*4882a593Smuzhiyun 					 int depth, void *data)
23*4882a593Smuzhiyun {
24*4882a593Smuzhiyun 	if (!of_flat_dt_is_compatible(node, "ibm,ultravisor"))
25*4882a593Smuzhiyun 		return 0;
26*4882a593Smuzhiyun 
27*4882a593Smuzhiyun 	powerpc_firmware_features |= FW_FEATURE_ULTRAVISOR;
28*4882a593Smuzhiyun 	pr_debug("Ultravisor detected!\n");
29*4882a593Smuzhiyun 	return 1;
30*4882a593Smuzhiyun }
31*4882a593Smuzhiyun 
32*4882a593Smuzhiyun static struct memcons *uv_memcons;
33*4882a593Smuzhiyun 
uv_msglog_read(struct file * file,struct kobject * kobj,struct bin_attribute * bin_attr,char * to,loff_t pos,size_t count)34*4882a593Smuzhiyun static ssize_t uv_msglog_read(struct file *file, struct kobject *kobj,
35*4882a593Smuzhiyun 			      struct bin_attribute *bin_attr, char *to,
36*4882a593Smuzhiyun 			      loff_t pos, size_t count)
37*4882a593Smuzhiyun {
38*4882a593Smuzhiyun 	return memcons_copy(uv_memcons, to, pos, count);
39*4882a593Smuzhiyun }
40*4882a593Smuzhiyun 
41*4882a593Smuzhiyun static struct bin_attribute uv_msglog_attr = {
42*4882a593Smuzhiyun 	.attr = {.name = "msglog", .mode = 0400},
43*4882a593Smuzhiyun 	.read = uv_msglog_read
44*4882a593Smuzhiyun };
45*4882a593Smuzhiyun 
uv_init(void)46*4882a593Smuzhiyun static int __init uv_init(void)
47*4882a593Smuzhiyun {
48*4882a593Smuzhiyun 	struct device_node *node;
49*4882a593Smuzhiyun 
50*4882a593Smuzhiyun 	if (!firmware_has_feature(FW_FEATURE_ULTRAVISOR))
51*4882a593Smuzhiyun 		return 0;
52*4882a593Smuzhiyun 
53*4882a593Smuzhiyun 	node = of_find_compatible_node(NULL, NULL, "ibm,uv-firmware");
54*4882a593Smuzhiyun 	if (!node)
55*4882a593Smuzhiyun 		return -ENODEV;
56*4882a593Smuzhiyun 
57*4882a593Smuzhiyun 	uv_memcons = memcons_init(node, "memcons");
58*4882a593Smuzhiyun 	of_node_put(node);
59*4882a593Smuzhiyun 	if (!uv_memcons)
60*4882a593Smuzhiyun 		return -ENOENT;
61*4882a593Smuzhiyun 
62*4882a593Smuzhiyun 	uv_msglog_attr.size = memcons_get_size(uv_memcons);
63*4882a593Smuzhiyun 
64*4882a593Smuzhiyun 	ultravisor_kobj = kobject_create_and_add("ultravisor", firmware_kobj);
65*4882a593Smuzhiyun 	if (!ultravisor_kobj)
66*4882a593Smuzhiyun 		return -ENOMEM;
67*4882a593Smuzhiyun 
68*4882a593Smuzhiyun 	return sysfs_create_bin_file(ultravisor_kobj, &uv_msglog_attr);
69*4882a593Smuzhiyun }
70*4882a593Smuzhiyun machine_subsys_initcall(powernv, uv_init);
71