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