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 * Get hypfs_diag0c_entry from CPU vector and store diag0c data 20 */ 21 static void diag0c_fn(void *data) 22 { 23 diag_stat_inc(DIAG_STAT_X00C); 24 diag_amode31_ops.diag0c(((void **)data)[smp_processor_id()]); 25 } 26 27 /* 28 * Allocate buffer and store diag 0c data 29 */ 30 static void *diag0c_store(unsigned int *count) 31 { 32 struct hypfs_diag0c_data *diag0c_data; 33 unsigned int cpu_count, cpu, i; 34 void **cpu_vec; 35 36 cpus_read_lock(); 37 cpu_count = num_online_cpus(); 38 cpu_vec = kmalloc_array(num_possible_cpus(), sizeof(*cpu_vec), 39 GFP_KERNEL); 40 if (!cpu_vec) 41 goto fail_unlock_cpus; 42 /* Note: Diag 0c needs 8 byte alignment and real storage */ 43 diag0c_data = kzalloc(struct_size(diag0c_data, entry, cpu_count), 44 GFP_KERNEL | GFP_DMA); 45 if (!diag0c_data) 46 goto fail_kfree_cpu_vec; 47 i = 0; 48 /* Fill CPU vector for each online CPU */ 49 for_each_online_cpu(cpu) { 50 diag0c_data->entry[i].cpu = cpu; 51 cpu_vec[cpu] = &diag0c_data->entry[i++]; 52 } 53 /* Collect data all CPUs */ 54 on_each_cpu(diag0c_fn, cpu_vec, 1); 55 *count = cpu_count; 56 kfree(cpu_vec); 57 cpus_read_unlock(); 58 return diag0c_data; 59 60 fail_kfree_cpu_vec: 61 kfree(cpu_vec); 62 fail_unlock_cpus: 63 cpus_read_unlock(); 64 return ERR_PTR(-ENOMEM); 65 } 66 67 /* 68 * Hypfs DBFS callback: Free diag 0c data 69 */ 70 static void dbfs_diag0c_free(const void *data) 71 { 72 kfree(data); 73 } 74 75 /* 76 * Hypfs DBFS callback: Create diag 0c data 77 */ 78 static int dbfs_diag0c_create(void **data, void **data_free_ptr, size_t *size) 79 { 80 struct hypfs_diag0c_data *diag0c_data; 81 unsigned int count; 82 83 diag0c_data = diag0c_store(&count); 84 if (IS_ERR(diag0c_data)) 85 return PTR_ERR(diag0c_data); 86 memset(&diag0c_data->hdr, 0, sizeof(diag0c_data->hdr)); 87 store_tod_clock_ext((union tod_clock *)diag0c_data->hdr.tod_ext); 88 diag0c_data->hdr.len = count * sizeof(struct hypfs_diag0c_entry); 89 diag0c_data->hdr.version = DBFS_D0C_HDR_VERSION; 90 diag0c_data->hdr.count = count; 91 *data = diag0c_data; 92 *data_free_ptr = diag0c_data; 93 *size = diag0c_data->hdr.len + sizeof(struct hypfs_diag0c_hdr); 94 return 0; 95 } 96 97 /* 98 * Hypfs DBFS file structure 99 */ 100 static struct hypfs_dbfs_file dbfs_file_0c = { 101 .name = "diag_0c", 102 .data_create = dbfs_diag0c_create, 103 .data_free = dbfs_diag0c_free, 104 }; 105 106 /* 107 * Initialize diag 0c interface for z/VM 108 */ 109 int __init hypfs_diag0c_init(void) 110 { 111 if (!MACHINE_IS_VM) 112 return 0; 113 hypfs_dbfs_create_file(&dbfs_file_0c); 114 return 0; 115 } 116 117 /* 118 * Shutdown diag 0c interface for z/VM 119 */ 120 void hypfs_diag0c_exit(void) 121 { 122 if (!MACHINE_IS_VM) 123 return; 124 hypfs_dbfs_remove_file(&dbfs_file_0c); 125 } 126