1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Copyright(c) 2020 Intel Corporation. */ 3 #include <linux/device.h> 4 #include <linux/slab.h> 5 #include <linux/idr.h> 6 #include <cxlmem.h> 7 #include <cxl.h> 8 #include "core.h" 9 10 /** 11 * DOC: cxl pmem 12 * 13 * The core CXL PMEM infrastructure supports persistent memory 14 * provisioning and serves as a bridge to the LIBNVDIMM subsystem. A CXL 15 * 'bridge' device is added at the root of a CXL device topology if 16 * platform firmware advertises at least one persistent memory capable 17 * CXL window. That root-level bridge corresponds to a LIBNVDIMM 'bus' 18 * device. Then for each cxl_memdev in the CXL device topology a bridge 19 * device is added to host a LIBNVDIMM dimm object. When these bridges 20 * are registered native LIBNVDIMM uapis are translated to CXL 21 * operations, for example, namespace label access commands. 22 */ 23 24 static DEFINE_IDA(cxl_nvdimm_bridge_ida); 25 26 static void cxl_nvdimm_bridge_release(struct device *dev) 27 { 28 struct cxl_nvdimm_bridge *cxl_nvb = to_cxl_nvdimm_bridge(dev); 29 30 ida_free(&cxl_nvdimm_bridge_ida, cxl_nvb->id); 31 kfree(cxl_nvb); 32 } 33 34 static const struct attribute_group *cxl_nvdimm_bridge_attribute_groups[] = { 35 &cxl_base_attribute_group, 36 NULL, 37 }; 38 39 const struct device_type cxl_nvdimm_bridge_type = { 40 .name = "cxl_nvdimm_bridge", 41 .release = cxl_nvdimm_bridge_release, 42 .groups = cxl_nvdimm_bridge_attribute_groups, 43 }; 44 45 struct cxl_nvdimm_bridge *to_cxl_nvdimm_bridge(struct device *dev) 46 { 47 if (dev_WARN_ONCE(dev, dev->type != &cxl_nvdimm_bridge_type, 48 "not a cxl_nvdimm_bridge device\n")) 49 return NULL; 50 return container_of(dev, struct cxl_nvdimm_bridge, dev); 51 } 52 EXPORT_SYMBOL_NS_GPL(to_cxl_nvdimm_bridge, CXL); 53 54 bool is_cxl_nvdimm_bridge(struct device *dev) 55 { 56 return dev->type == &cxl_nvdimm_bridge_type; 57 } 58 EXPORT_SYMBOL_NS_GPL(is_cxl_nvdimm_bridge, CXL); 59 60 static int match_nvdimm_bridge(struct device *dev, void *data) 61 { 62 return is_cxl_nvdimm_bridge(dev); 63 } 64 65 struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct device *start) 66 { 67 struct cxl_port *port = find_cxl_root(start); 68 struct device *dev; 69 70 if (!port) 71 return NULL; 72 73 dev = device_find_child(&port->dev, NULL, match_nvdimm_bridge); 74 put_device(&port->dev); 75 76 if (!dev) 77 return NULL; 78 79 return to_cxl_nvdimm_bridge(dev); 80 } 81 EXPORT_SYMBOL_NS_GPL(cxl_find_nvdimm_bridge, CXL); 82 83 static struct lock_class_key cxl_nvdimm_bridge_key; 84 85 static struct cxl_nvdimm_bridge *cxl_nvdimm_bridge_alloc(struct cxl_port *port) 86 { 87 struct cxl_nvdimm_bridge *cxl_nvb; 88 struct device *dev; 89 int rc; 90 91 cxl_nvb = kzalloc(sizeof(*cxl_nvb), GFP_KERNEL); 92 if (!cxl_nvb) 93 return ERR_PTR(-ENOMEM); 94 95 rc = ida_alloc(&cxl_nvdimm_bridge_ida, GFP_KERNEL); 96 if (rc < 0) 97 goto err; 98 cxl_nvb->id = rc; 99 100 dev = &cxl_nvb->dev; 101 cxl_nvb->port = port; 102 cxl_nvb->state = CXL_NVB_NEW; 103 device_initialize(dev); 104 lockdep_set_class(&dev->mutex, &cxl_nvdimm_bridge_key); 105 device_set_pm_not_required(dev); 106 dev->parent = &port->dev; 107 dev->bus = &cxl_bus_type; 108 dev->type = &cxl_nvdimm_bridge_type; 109 110 return cxl_nvb; 111 112 err: 113 kfree(cxl_nvb); 114 return ERR_PTR(rc); 115 } 116 117 static void unregister_nvb(void *_cxl_nvb) 118 { 119 struct cxl_nvdimm_bridge *cxl_nvb = _cxl_nvb; 120 bool flush; 121 122 /* 123 * If the bridge was ever activated then there might be in-flight state 124 * work to flush. Once the state has been changed to 'dead' then no new 125 * work can be queued by user-triggered bind. 126 */ 127 device_lock(&cxl_nvb->dev); 128 flush = cxl_nvb->state != CXL_NVB_NEW; 129 cxl_nvb->state = CXL_NVB_DEAD; 130 device_unlock(&cxl_nvb->dev); 131 132 /* 133 * Even though the device core will trigger device_release_driver() 134 * before the unregister, it does not know about the fact that 135 * cxl_nvdimm_bridge_driver defers ->remove() work. So, do the driver 136 * release not and flush it before tearing down the nvdimm device 137 * hierarchy. 138 */ 139 device_release_driver(&cxl_nvb->dev); 140 if (flush) 141 flush_work(&cxl_nvb->state_work); 142 device_unregister(&cxl_nvb->dev); 143 } 144 145 /** 146 * devm_cxl_add_nvdimm_bridge() - add the root of a LIBNVDIMM topology 147 * @host: platform firmware root device 148 * @port: CXL port at the root of a CXL topology 149 * 150 * Return: bridge device that can host cxl_nvdimm objects 151 */ 152 struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host, 153 struct cxl_port *port) 154 { 155 struct cxl_nvdimm_bridge *cxl_nvb; 156 struct device *dev; 157 int rc; 158 159 if (!IS_ENABLED(CONFIG_CXL_PMEM)) 160 return ERR_PTR(-ENXIO); 161 162 cxl_nvb = cxl_nvdimm_bridge_alloc(port); 163 if (IS_ERR(cxl_nvb)) 164 return cxl_nvb; 165 166 dev = &cxl_nvb->dev; 167 rc = dev_set_name(dev, "nvdimm-bridge%d", cxl_nvb->id); 168 if (rc) 169 goto err; 170 171 rc = device_add(dev); 172 if (rc) 173 goto err; 174 175 rc = devm_add_action_or_reset(host, unregister_nvb, cxl_nvb); 176 if (rc) 177 return ERR_PTR(rc); 178 179 return cxl_nvb; 180 181 err: 182 put_device(dev); 183 return ERR_PTR(rc); 184 } 185 EXPORT_SYMBOL_NS_GPL(devm_cxl_add_nvdimm_bridge, CXL); 186 187 static void cxl_nvdimm_release(struct device *dev) 188 { 189 struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev); 190 191 kfree(cxl_nvd); 192 } 193 194 static const struct attribute_group *cxl_nvdimm_attribute_groups[] = { 195 &cxl_base_attribute_group, 196 NULL, 197 }; 198 199 const struct device_type cxl_nvdimm_type = { 200 .name = "cxl_nvdimm", 201 .release = cxl_nvdimm_release, 202 .groups = cxl_nvdimm_attribute_groups, 203 }; 204 205 bool is_cxl_nvdimm(struct device *dev) 206 { 207 return dev->type == &cxl_nvdimm_type; 208 } 209 EXPORT_SYMBOL_NS_GPL(is_cxl_nvdimm, CXL); 210 211 struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev) 212 { 213 if (dev_WARN_ONCE(dev, !is_cxl_nvdimm(dev), 214 "not a cxl_nvdimm device\n")) 215 return NULL; 216 return container_of(dev, struct cxl_nvdimm, dev); 217 } 218 EXPORT_SYMBOL_NS_GPL(to_cxl_nvdimm, CXL); 219 220 static struct lock_class_key cxl_nvdimm_key; 221 222 static struct cxl_nvdimm *cxl_nvdimm_alloc(struct cxl_memdev *cxlmd) 223 { 224 struct cxl_nvdimm *cxl_nvd; 225 struct device *dev; 226 227 cxl_nvd = kzalloc(sizeof(*cxl_nvd), GFP_KERNEL); 228 if (!cxl_nvd) 229 return ERR_PTR(-ENOMEM); 230 231 dev = &cxl_nvd->dev; 232 cxl_nvd->cxlmd = cxlmd; 233 device_initialize(dev); 234 lockdep_set_class(&dev->mutex, &cxl_nvdimm_key); 235 device_set_pm_not_required(dev); 236 dev->parent = &cxlmd->dev; 237 dev->bus = &cxl_bus_type; 238 dev->type = &cxl_nvdimm_type; 239 240 return cxl_nvd; 241 } 242 243 static void cxl_nvd_unregister(void *dev) 244 { 245 device_unregister(dev); 246 } 247 248 /** 249 * devm_cxl_add_nvdimm() - add a bridge between a cxl_memdev and an nvdimm 250 * @host: same host as @cxlmd 251 * @cxlmd: cxl_memdev instance that will perform LIBNVDIMM operations 252 * 253 * Return: 0 on success negative error code on failure. 254 */ 255 int devm_cxl_add_nvdimm(struct device *host, struct cxl_memdev *cxlmd) 256 { 257 struct cxl_nvdimm *cxl_nvd; 258 struct device *dev; 259 int rc; 260 261 cxl_nvd = cxl_nvdimm_alloc(cxlmd); 262 if (IS_ERR(cxl_nvd)) 263 return PTR_ERR(cxl_nvd); 264 265 dev = &cxl_nvd->dev; 266 rc = dev_set_name(dev, "pmem%d", cxlmd->id); 267 if (rc) 268 goto err; 269 270 rc = device_add(dev); 271 if (rc) 272 goto err; 273 274 dev_dbg(host, "%s: register %s\n", dev_name(dev->parent), 275 dev_name(dev)); 276 277 return devm_add_action_or_reset(host, cxl_nvd_unregister, dev); 278 279 err: 280 put_device(dev); 281 return rc; 282 } 283 EXPORT_SYMBOL_NS_GPL(devm_cxl_add_nvdimm, CXL); 284