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