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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 130 void hypfs_diag0c_exit(void) 131 { 132 if (!MACHINE_IS_VM) 133 return; 134 hypfs_dbfs_remove_file(&dbfs_file_0c); 135 } 136