tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Hypervisor filesystem for Linux on s390
4 *
5 * Diag 0C implementation
6 *
7 * Copyright IBM Corp. 2014
8 */
9
10#include <linux/slab.h>
11#include <linux/cpu.h>
12#include <asm/diag.h>
13#include <asm/hypfs.h>
14#include "hypfs.h"
15
16#define DBFS_D0C_HDR_VERSION 0
17
18/*
19 * Execute diagnose 0c in 31 bit mode
20 */
21static void diag0c(struct hypfs_diag0c_entry *entry)
22{
23 diag_stat_inc(DIAG_STAT_X00C);
24 asm volatile (
25 " sam31\n"
26 " diag %0,%0,0x0c\n"
27 " sam64\n"
28 : /* no output register */
29 : "a" (entry)
30 : "memory");
31}
32
33/*
34 * Get hypfs_diag0c_entry from CPU vector and store diag0c data
35 */
36static void diag0c_fn(void *data)
37{
38 diag0c(((void **) data)[smp_processor_id()]);
39}
40
41/*
42 * Allocate buffer and store diag 0c data
43 */
44static void *diag0c_store(unsigned int *count)
45{
46 struct hypfs_diag0c_data *diag0c_data;
47 unsigned int cpu_count, cpu, i;
48 void **cpu_vec;
49
50 get_online_cpus();
51 cpu_count = num_online_cpus();
52 cpu_vec = kmalloc_array(num_possible_cpus(), sizeof(*cpu_vec),
53 GFP_KERNEL);
54 if (!cpu_vec)
55 goto fail_put_online_cpus;
56 /* Note: Diag 0c needs 8 byte alignment and real storage */
57 diag0c_data = kzalloc(sizeof(struct hypfs_diag0c_hdr) +
58 cpu_count * sizeof(struct hypfs_diag0c_entry),
59 GFP_KERNEL | GFP_DMA);
60 if (!diag0c_data)
61 goto fail_kfree_cpu_vec;
62 i = 0;
63 /* Fill CPU vector for each online CPU */
64 for_each_online_cpu(cpu) {
65 diag0c_data->entry[i].cpu = cpu;
66 cpu_vec[cpu] = &diag0c_data->entry[i++];
67 }
68 /* Collect data all CPUs */
69 on_each_cpu(diag0c_fn, cpu_vec, 1);
70 *count = cpu_count;
71 kfree(cpu_vec);
72 put_online_cpus();
73 return diag0c_data;
74
75fail_kfree_cpu_vec:
76 kfree(cpu_vec);
77fail_put_online_cpus:
78 put_online_cpus();
79 return ERR_PTR(-ENOMEM);
80}
81
82/*
83 * Hypfs DBFS callback: Free diag 0c data
84 */
85static void dbfs_diag0c_free(const void *data)
86{
87 kfree(data);
88}
89
90/*
91 * Hypfs DBFS callback: Create diag 0c data
92 */
93static int dbfs_diag0c_create(void **data, void **data_free_ptr, size_t *size)
94{
95 struct hypfs_diag0c_data *diag0c_data;
96 unsigned int count;
97
98 diag0c_data = diag0c_store(&count);
99 if (IS_ERR(diag0c_data))
100 return PTR_ERR(diag0c_data);
101 memset(&diag0c_data->hdr, 0, sizeof(diag0c_data->hdr));
102 get_tod_clock_ext(diag0c_data->hdr.tod_ext);
103 diag0c_data->hdr.len = count * sizeof(struct hypfs_diag0c_entry);
104 diag0c_data->hdr.version = DBFS_D0C_HDR_VERSION;
105 diag0c_data->hdr.count = count;
106 *data = diag0c_data;
107 *data_free_ptr = diag0c_data;
108 *size = diag0c_data->hdr.len + sizeof(struct hypfs_diag0c_hdr);
109 return 0;
110}
111
112/*
113 * Hypfs DBFS file structure
114 */
115static struct hypfs_dbfs_file dbfs_file_0c = {
116 .name = "diag_0c",
117 .data_create = dbfs_diag0c_create,
118 .data_free = dbfs_diag0c_free,
119};
120
121/*
122 * Initialize diag 0c interface for z/VM
123 */
124int __init hypfs_diag0c_init(void)
125{
126 if (!MACHINE_IS_VM)
127 return 0;
128 return hypfs_dbfs_create_file(&dbfs_file_0c);
129}
130
131/*
132 * Shutdown diag 0c interface for z/VM
133 */
134void hypfs_diag0c_exit(void)
135{
136 if (!MACHINE_IS_VM)
137 return;
138 hypfs_dbfs_remove_file(&dbfs_file_0c);
139}