1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2010 Brian King IBM Corporation 4 */ 5 6 #include <linux/cpu.h> 7 #include <linux/delay.h> 8 #include <linux/suspend.h> 9 #include <linux/stat.h> 10 #include <asm/firmware.h> 11 #include <asm/hvcall.h> 12 #include <asm/machdep.h> 13 #include <asm/mmu.h> 14 #include <asm/rtas.h> 15 #include <asm/topology.h> 16 #include "../../kernel/cacheinfo.h" 17 18 static u64 stream_id; 19 static struct device suspend_dev; 20 static DECLARE_COMPLETION(suspend_work); 21 static struct rtas_suspend_me_data suspend_data; 22 static atomic_t suspending; 23 24 /** 25 * pseries_suspend_begin - First phase of hibernation 26 * 27 * Check to ensure we are in a valid state to hibernate 28 * 29 * Return value: 30 * 0 on success / other on failure 31 **/ 32 static int pseries_suspend_begin(suspend_state_t state) 33 { 34 long vasi_state, rc; 35 unsigned long retbuf[PLPAR_HCALL_BUFSIZE]; 36 37 /* Make sure the state is valid */ 38 rc = plpar_hcall(H_VASI_STATE, retbuf, stream_id); 39 40 vasi_state = retbuf[0]; 41 42 if (rc) { 43 pr_err("pseries_suspend_begin: vasi_state returned %ld\n",rc); 44 return rc; 45 } else if (vasi_state == H_VASI_ENABLED) { 46 return -EAGAIN; 47 } else if (vasi_state != H_VASI_SUSPENDING) { 48 pr_err("pseries_suspend_begin: vasi_state returned state %ld\n", 49 vasi_state); 50 return -EIO; 51 } 52 53 return 0; 54 } 55 56 /** 57 * pseries_suspend_cpu - Suspend a single CPU 58 * 59 * Makes the H_JOIN call to suspend the CPU 60 * 61 **/ 62 static int pseries_suspend_cpu(void) 63 { 64 if (atomic_read(&suspending)) 65 return rtas_suspend_cpu(&suspend_data); 66 return 0; 67 } 68 69 /** 70 * pseries_suspend_enable_irqs 71 * 72 * Post suspend configuration updates 73 * 74 **/ 75 static void pseries_suspend_enable_irqs(void) 76 { 77 /* 78 * Update configuration which can be modified based on device tree 79 * changes during resume. 80 */ 81 cacheinfo_cpu_offline(smp_processor_id()); 82 post_mobility_fixup(); 83 cacheinfo_cpu_online(smp_processor_id()); 84 } 85 86 /** 87 * pseries_suspend_enter - Final phase of hibernation 88 * 89 * Return value: 90 * 0 on success / other on failure 91 **/ 92 static int pseries_suspend_enter(suspend_state_t state) 93 { 94 int rc = rtas_suspend_last_cpu(&suspend_data); 95 96 atomic_set(&suspending, 0); 97 atomic_set(&suspend_data.done, 1); 98 return rc; 99 } 100 101 /** 102 * pseries_prepare_late - Prepare to suspend all other CPUs 103 * 104 * Return value: 105 * 0 on success / other on failure 106 **/ 107 static int pseries_prepare_late(void) 108 { 109 atomic_set(&suspending, 1); 110 atomic_set(&suspend_data.working, 0); 111 atomic_set(&suspend_data.done, 0); 112 atomic_set(&suspend_data.error, 0); 113 suspend_data.complete = &suspend_work; 114 reinit_completion(&suspend_work); 115 return 0; 116 } 117 118 /** 119 * store_hibernate - Initiate partition hibernation 120 * @dev: subsys root device 121 * @attr: device attribute struct 122 * @buf: buffer 123 * @count: buffer size 124 * 125 * Write the stream ID received from the HMC to this file 126 * to trigger hibernating the partition 127 * 128 * Return value: 129 * number of bytes printed to buffer / other on failure 130 **/ 131 static ssize_t store_hibernate(struct device *dev, 132 struct device_attribute *attr, 133 const char *buf, size_t count) 134 { 135 int rc; 136 137 if (!capable(CAP_SYS_ADMIN)) 138 return -EPERM; 139 140 stream_id = simple_strtoul(buf, NULL, 16); 141 142 do { 143 rc = pseries_suspend_begin(PM_SUSPEND_MEM); 144 if (rc == -EAGAIN) 145 ssleep(1); 146 } while (rc == -EAGAIN); 147 148 if (!rc) 149 rc = pm_suspend(PM_SUSPEND_MEM); 150 151 stream_id = 0; 152 153 if (!rc) 154 rc = count; 155 156 return rc; 157 } 158 159 #define USER_DT_UPDATE 0 160 #define KERN_DT_UPDATE 1 161 162 /** 163 * show_hibernate - Report device tree update responsibilty 164 * @dev: subsys root device 165 * @attr: device attribute struct 166 * @buf: buffer 167 * 168 * Report whether a device tree update is performed by the kernel after a 169 * resume, or if drmgr must coordinate the update from user space. 170 * 171 * Return value: 172 * 0 if drmgr is to initiate update, and 1 otherwise 173 **/ 174 static ssize_t show_hibernate(struct device *dev, 175 struct device_attribute *attr, 176 char *buf) 177 { 178 return sprintf(buf, "%d\n", KERN_DT_UPDATE); 179 } 180 181 static DEVICE_ATTR(hibernate, 0644, show_hibernate, store_hibernate); 182 183 static struct bus_type suspend_subsys = { 184 .name = "power", 185 .dev_name = "power", 186 }; 187 188 static const struct platform_suspend_ops pseries_suspend_ops = { 189 .valid = suspend_valid_only_mem, 190 .begin = pseries_suspend_begin, 191 .prepare_late = pseries_prepare_late, 192 .enter = pseries_suspend_enter, 193 }; 194 195 /** 196 * pseries_suspend_sysfs_register - Register with sysfs 197 * 198 * Return value: 199 * 0 on success / other on failure 200 **/ 201 static int pseries_suspend_sysfs_register(struct device *dev) 202 { 203 int rc; 204 205 if ((rc = subsys_system_register(&suspend_subsys, NULL))) 206 return rc; 207 208 dev->id = 0; 209 dev->bus = &suspend_subsys; 210 211 if ((rc = device_create_file(suspend_subsys.dev_root, &dev_attr_hibernate))) 212 goto subsys_unregister; 213 214 return 0; 215 216 subsys_unregister: 217 bus_unregister(&suspend_subsys); 218 return rc; 219 } 220 221 /** 222 * pseries_suspend_init - initcall for pSeries suspend 223 * 224 * Return value: 225 * 0 on success / other on failure 226 **/ 227 static int __init pseries_suspend_init(void) 228 { 229 int rc; 230 231 if (!firmware_has_feature(FW_FEATURE_LPAR)) 232 return 0; 233 234 suspend_data.token = rtas_token("ibm,suspend-me"); 235 if (suspend_data.token == RTAS_UNKNOWN_SERVICE) 236 return 0; 237 238 if ((rc = pseries_suspend_sysfs_register(&suspend_dev))) 239 return rc; 240 241 ppc_md.suspend_disable_cpu = pseries_suspend_cpu; 242 ppc_md.suspend_enable_irqs = pseries_suspend_enable_irqs; 243 suspend_set_ops(&pseries_suspend_ops); 244 return 0; 245 } 246 machine_device_initcall(pseries, pseries_suspend_init); 247