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