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(sizeof(*cpu_vec) * num_possible_cpus(), GFP_KERNEL); 53 if (!cpu_vec) 54 goto fail_put_online_cpus; 55 /* Note: Diag 0c needs 8 byte alignment and real storage */ 56 diag0c_data = kzalloc(sizeof(struct hypfs_diag0c_hdr) + 57 cpu_count * sizeof(struct hypfs_diag0c_entry), 58 GFP_KERNEL | GFP_DMA); 59 if (!diag0c_data) 60 goto fail_kfree_cpu_vec; 61 i = 0; 62 /* Fill CPU vector for each online CPU */ 63 for_each_online_cpu(cpu) { 64 diag0c_data->entry[i].cpu = cpu; 65 cpu_vec[cpu] = &diag0c_data->entry[i++]; 66 } 67 /* Collect data all CPUs */ 68 on_each_cpu(diag0c_fn, cpu_vec, 1); 69 *count = cpu_count; 70 kfree(cpu_vec); 71 put_online_cpus(); 72 return diag0c_data; 73 74 fail_kfree_cpu_vec: 75 kfree(cpu_vec); 76 fail_put_online_cpus: 77 put_online_cpus(); 78 return ERR_PTR(-ENOMEM); 79 } 80 81 /* 82 * Hypfs DBFS callback: Free diag 0c data 83 */ 84 static void dbfs_diag0c_free(const void *data) 85 { 86 kfree(data); 87 } 88 89 /* 90 * Hypfs DBFS callback: Create diag 0c data 91 */ 92 static int dbfs_diag0c_create(void **data, void **data_free_ptr, size_t *size) 93 { 94 struct hypfs_diag0c_data *diag0c_data; 95 unsigned int count; 96 97 diag0c_data = diag0c_store(&count); 98 if (IS_ERR(diag0c_data)) 99 return PTR_ERR(diag0c_data); 100 memset(&diag0c_data->hdr, 0, sizeof(diag0c_data->hdr)); 101 get_tod_clock_ext(diag0c_data->hdr.tod_ext); 102 diag0c_data->hdr.len = count * sizeof(struct hypfs_diag0c_entry); 103 diag0c_data->hdr.version = DBFS_D0C_HDR_VERSION; 104 diag0c_data->hdr.count = count; 105 *data = diag0c_data; 106 *data_free_ptr = diag0c_data; 107 *size = diag0c_data->hdr.len + sizeof(struct hypfs_diag0c_hdr); 108 return 0; 109 } 110 111 /* 112 * Hypfs DBFS file structure 113 */ 114 static struct hypfs_dbfs_file dbfs_file_0c = { 115 .name = "diag_0c", 116 .data_create = dbfs_diag0c_create, 117 .data_free = dbfs_diag0c_free, 118 }; 119 120 /* 121 * Initialize diag 0c interface for z/VM 122 */ 123 int __init hypfs_diag0c_init(void) 124 { 125 if (!MACHINE_IS_VM) 126 return 0; 127 return hypfs_dbfs_create_file(&dbfs_file_0c); 128 } 129 130 /* 131 * Shutdown diag 0c interface for z/VM 132 */ 133 void hypfs_diag0c_exit(void) 134 { 135 if (!MACHINE_IS_VM) 136 return; 137 hypfs_dbfs_remove_file(&dbfs_file_0c); 138 } 139