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 __mock int match_nvdimm_bridge(struct device *dev, const void *data) 61 { 62 return is_cxl_nvdimm_bridge(dev); 63 } 64 65 struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_nvdimm *cxl_nvd) 66 { 67 struct device *dev; 68 69 dev = bus_find_device(&cxl_bus_type, NULL, cxl_nvd, match_nvdimm_bridge); 70 if (!dev) 71 return NULL; 72 return to_cxl_nvdimm_bridge(dev); 73 } 74 EXPORT_SYMBOL_NS_GPL(cxl_find_nvdimm_bridge, CXL); 75 76 static struct cxl_nvdimm_bridge * 77 cxl_nvdimm_bridge_alloc(struct cxl_port *port) 78 { 79 struct cxl_nvdimm_bridge *cxl_nvb; 80 struct device *dev; 81 int rc; 82 83 cxl_nvb = kzalloc(sizeof(*cxl_nvb), GFP_KERNEL); 84 if (!cxl_nvb) 85 return ERR_PTR(-ENOMEM); 86 87 rc = ida_alloc(&cxl_nvdimm_bridge_ida, GFP_KERNEL); 88 if (rc < 0) 89 goto err; 90 cxl_nvb->id = rc; 91 92 dev = &cxl_nvb->dev; 93 cxl_nvb->port = port; 94 cxl_nvb->state = CXL_NVB_NEW; 95 device_initialize(dev); 96 device_set_pm_not_required(dev); 97 dev->parent = &port->dev; 98 dev->bus = &cxl_bus_type; 99 dev->type = &cxl_nvdimm_bridge_type; 100 101 return cxl_nvb; 102 103 err: 104 kfree(cxl_nvb); 105 return ERR_PTR(rc); 106 } 107 108 static void unregister_nvb(void *_cxl_nvb) 109 { 110 struct cxl_nvdimm_bridge *cxl_nvb = _cxl_nvb; 111 bool flush; 112 113 /* 114 * If the bridge was ever activated then there might be in-flight state 115 * work to flush. Once the state has been changed to 'dead' then no new 116 * work can be queued by user-triggered bind. 117 */ 118 device_lock(&cxl_nvb->dev); 119 flush = cxl_nvb->state != CXL_NVB_NEW; 120 cxl_nvb->state = CXL_NVB_DEAD; 121 device_unlock(&cxl_nvb->dev); 122 123 /* 124 * Even though the device core will trigger device_release_driver() 125 * before the unregister, it does not know about the fact that 126 * cxl_nvdimm_bridge_driver defers ->remove() work. So, do the driver 127 * release not and flush it before tearing down the nvdimm device 128 * hierarchy. 129 */ 130 device_release_driver(&cxl_nvb->dev); 131 if (flush) 132 flush_work(&cxl_nvb->state_work); 133 device_unregister(&cxl_nvb->dev); 134 } 135 136 /** 137 * devm_cxl_add_nvdimm_bridge() - add the root of a LIBNVDIMM topology 138 * @host: platform firmware root device 139 * @port: CXL port at the root of a CXL topology 140 * 141 * Return: bridge device that can host cxl_nvdimm objects 142 */ 143 struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host, 144 struct cxl_port *port) 145 { 146 struct cxl_nvdimm_bridge *cxl_nvb; 147 struct device *dev; 148 int rc; 149 150 if (!IS_ENABLED(CONFIG_CXL_PMEM)) 151 return ERR_PTR(-ENXIO); 152 153 cxl_nvb = cxl_nvdimm_bridge_alloc(port); 154 if (IS_ERR(cxl_nvb)) 155 return cxl_nvb; 156 157 dev = &cxl_nvb->dev; 158 rc = dev_set_name(dev, "nvdimm-bridge%d", cxl_nvb->id); 159 if (rc) 160 goto err; 161 162 rc = device_add(dev); 163 if (rc) 164 goto err; 165 166 rc = devm_add_action_or_reset(host, unregister_nvb, cxl_nvb); 167 if (rc) 168 return ERR_PTR(rc); 169 170 return cxl_nvb; 171 172 err: 173 put_device(dev); 174 return ERR_PTR(rc); 175 } 176 EXPORT_SYMBOL_NS_GPL(devm_cxl_add_nvdimm_bridge, CXL); 177 178 static void cxl_nvdimm_release(struct device *dev) 179 { 180 struct cxl_nvdimm *cxl_nvd = to_cxl_nvdimm(dev); 181 182 kfree(cxl_nvd); 183 } 184 185 static const struct attribute_group *cxl_nvdimm_attribute_groups[] = { 186 &cxl_base_attribute_group, 187 NULL, 188 }; 189 190 const struct device_type cxl_nvdimm_type = { 191 .name = "cxl_nvdimm", 192 .release = cxl_nvdimm_release, 193 .groups = cxl_nvdimm_attribute_groups, 194 }; 195 196 bool is_cxl_nvdimm(struct device *dev) 197 { 198 return dev->type == &cxl_nvdimm_type; 199 } 200 EXPORT_SYMBOL_NS_GPL(is_cxl_nvdimm, CXL); 201 202 struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev) 203 { 204 if (dev_WARN_ONCE(dev, !is_cxl_nvdimm(dev), 205 "not a cxl_nvdimm device\n")) 206 return NULL; 207 return container_of(dev, struct cxl_nvdimm, dev); 208 } 209 EXPORT_SYMBOL_NS_GPL(to_cxl_nvdimm, CXL); 210 211 static struct cxl_nvdimm *cxl_nvdimm_alloc(struct cxl_memdev *cxlmd) 212 { 213 struct cxl_nvdimm *cxl_nvd; 214 struct device *dev; 215 216 cxl_nvd = kzalloc(sizeof(*cxl_nvd), GFP_KERNEL); 217 if (!cxl_nvd) 218 return ERR_PTR(-ENOMEM); 219 220 dev = &cxl_nvd->dev; 221 cxl_nvd->cxlmd = cxlmd; 222 device_initialize(dev); 223 device_set_pm_not_required(dev); 224 dev->parent = &cxlmd->dev; 225 dev->bus = &cxl_bus_type; 226 dev->type = &cxl_nvdimm_type; 227 228 return cxl_nvd; 229 } 230 231 static void cxl_nvd_unregister(void *dev) 232 { 233 device_unregister(dev); 234 } 235 236 /** 237 * devm_cxl_add_nvdimm() - add a bridge between a cxl_memdev and an nvdimm 238 * @host: same host as @cxlmd 239 * @cxlmd: cxl_memdev instance that will perform LIBNVDIMM operations 240 * 241 * Return: 0 on success negative error code on failure. 242 */ 243 int devm_cxl_add_nvdimm(struct device *host, struct cxl_memdev *cxlmd) 244 { 245 struct cxl_nvdimm *cxl_nvd; 246 struct device *dev; 247 int rc; 248 249 cxl_nvd = cxl_nvdimm_alloc(cxlmd); 250 if (IS_ERR(cxl_nvd)) 251 return PTR_ERR(cxl_nvd); 252 253 dev = &cxl_nvd->dev; 254 rc = dev_set_name(dev, "pmem%d", cxlmd->id); 255 if (rc) 256 goto err; 257 258 rc = device_add(dev); 259 if (rc) 260 goto err; 261 262 dev_dbg(host, "%s: register %s\n", dev_name(dev->parent), 263 dev_name(dev)); 264 265 return devm_add_action_or_reset(host, cxl_nvd_unregister, dev); 266 267 err: 268 put_device(dev); 269 return rc; 270 } 271 EXPORT_SYMBOL_NS_GPL(devm_cxl_add_nvdimm, CXL); 272