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 */ 21 static 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 */ 36 static 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 */ 44 static 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 75 fail_kfree_cpu_vec: 76 kfree(cpu_vec); 77 fail_put_online_cpus: 78 put_online_cpus(); 79 return ERR_PTR(-ENOMEM); 80 } 81 82 /* 83 * Hypfs DBFS callback: Free diag 0c data 84 */ 85 static void dbfs_diag0c_free(const void *data) 86 { 87 kfree(data); 88 } 89 90 /* 91 * Hypfs DBFS callback: Create diag 0c data 92 */ 93 static 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 */ 115 static 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 */ 124 int __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 */ 134 void hypfs_diag0c_exit(void) 135 { 136 if (!MACHINE_IS_VM) 137 return; 138 hypfs_dbfs_remove_file(&dbfs_file_0c); 139 } 140