1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright 2014 IBM Corp. 4 */ 5 6 #include <linux/spinlock.h> 7 #include <linux/kernel.h> 8 #include <linux/module.h> 9 #include <linux/device.h> 10 #include <linux/mutex.h> 11 #include <linux/init.h> 12 #include <linux/list.h> 13 #include <linux/mm.h> 14 #include <linux/of.h> 15 #include <linux/slab.h> 16 #include <linux/idr.h> 17 #include <linux/pci.h> 18 #include <linux/platform_device.h> 19 #include <linux/sched/task.h> 20 21 #include <asm/cputable.h> 22 #include <asm/mmu.h> 23 #include <misc/cxl-base.h> 24 25 #include "cxl.h" 26 #include "trace.h" 27 28 static DEFINE_SPINLOCK(adapter_idr_lock); 29 static DEFINE_IDR(cxl_adapter_idr); 30 31 uint cxl_verbose; 32 module_param_named(verbose, cxl_verbose, uint, 0600); 33 MODULE_PARM_DESC(verbose, "Enable verbose dmesg output"); 34 35 const struct cxl_backend_ops *cxl_ops; 36 37 int cxl_afu_slbia(struct cxl_afu *afu) 38 { 39 unsigned long timeout = jiffies + (HZ * CXL_TIMEOUT); 40 41 pr_devel("cxl_afu_slbia issuing SLBIA command\n"); 42 cxl_p2n_write(afu, CXL_SLBIA_An, CXL_TLB_SLB_IQ_ALL); 43 while (cxl_p2n_read(afu, CXL_SLBIA_An) & CXL_TLB_SLB_P) { 44 if (time_after_eq(jiffies, timeout)) { 45 dev_warn(&afu->dev, "WARNING: CXL AFU SLBIA timed out!\n"); 46 return -EBUSY; 47 } 48 /* If the adapter has gone down, we can assume that we 49 * will PERST it and that will invalidate everything. 50 */ 51 if (!cxl_ops->link_ok(afu->adapter, afu)) 52 return -EIO; 53 cpu_relax(); 54 } 55 return 0; 56 } 57 58 static inline void _cxl_slbia(struct cxl_context *ctx, struct mm_struct *mm) 59 { 60 unsigned long flags; 61 62 if (ctx->mm != mm) 63 return; 64 65 pr_devel("%s matched mm - card: %i afu: %i pe: %i\n", __func__, 66 ctx->afu->adapter->adapter_num, ctx->afu->slice, ctx->pe); 67 68 spin_lock_irqsave(&ctx->sste_lock, flags); 69 trace_cxl_slbia(ctx); 70 memset(ctx->sstp, 0, ctx->sst_size); 71 spin_unlock_irqrestore(&ctx->sste_lock, flags); 72 mb(); 73 cxl_afu_slbia(ctx->afu); 74 } 75 76 static inline void cxl_slbia_core(struct mm_struct *mm) 77 { 78 struct cxl *adapter; 79 struct cxl_afu *afu; 80 struct cxl_context *ctx; 81 int card, slice, id; 82 83 pr_devel("%s called\n", __func__); 84 85 spin_lock(&adapter_idr_lock); 86 idr_for_each_entry(&cxl_adapter_idr, adapter, card) { 87 /* XXX: Make this lookup faster with link from mm to ctx */ 88 spin_lock(&adapter->afu_list_lock); 89 for (slice = 0; slice < adapter->slices; slice++) { 90 afu = adapter->afu[slice]; 91 if (!afu || !afu->enabled) 92 continue; 93 rcu_read_lock(); 94 idr_for_each_entry(&afu->contexts_idr, ctx, id) 95 _cxl_slbia(ctx, mm); 96 rcu_read_unlock(); 97 } 98 spin_unlock(&adapter->afu_list_lock); 99 } 100 spin_unlock(&adapter_idr_lock); 101 } 102 103 static struct cxl_calls cxl_calls = { 104 .cxl_slbia = cxl_slbia_core, 105 .owner = THIS_MODULE, 106 }; 107 108 int cxl_alloc_sst(struct cxl_context *ctx) 109 { 110 unsigned long vsid; 111 u64 ea_mask, size, sstp0, sstp1; 112 113 sstp0 = 0; 114 sstp1 = 0; 115 116 ctx->sst_size = PAGE_SIZE; 117 ctx->sst_lru = 0; 118 ctx->sstp = (struct cxl_sste *)get_zeroed_page(GFP_KERNEL); 119 if (!ctx->sstp) { 120 pr_err("cxl_alloc_sst: Unable to allocate segment table\n"); 121 return -ENOMEM; 122 } 123 pr_devel("SSTP allocated at 0x%p\n", ctx->sstp); 124 125 vsid = get_kernel_vsid((u64)ctx->sstp, mmu_kernel_ssize) << 12; 126 127 sstp0 |= (u64)mmu_kernel_ssize << CXL_SSTP0_An_B_SHIFT; 128 sstp0 |= (SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp) << 50; 129 130 size = (((u64)ctx->sst_size >> 8) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT; 131 if (unlikely(size & ~CXL_SSTP0_An_SegTableSize_MASK)) { 132 WARN(1, "Impossible segment table size\n"); 133 return -EINVAL; 134 } 135 sstp0 |= size; 136 137 if (mmu_kernel_ssize == MMU_SEGSIZE_256M) 138 ea_mask = 0xfffff00ULL; 139 else 140 ea_mask = 0xffffffff00ULL; 141 142 sstp0 |= vsid >> (50-14); /* Top 14 bits of VSID */ 143 sstp1 |= (vsid << (64-(50-14))) & ~ea_mask; 144 sstp1 |= (u64)ctx->sstp & ea_mask; 145 sstp1 |= CXL_SSTP1_An_V; 146 147 pr_devel("Looked up %#llx: slbfee. %#llx (ssize: %x, vsid: %#lx), copied to SSTP0: %#llx, SSTP1: %#llx\n", 148 (u64)ctx->sstp, (u64)ctx->sstp & ESID_MASK, mmu_kernel_ssize, vsid, sstp0, sstp1); 149 150 /* Store calculated sstp hardware points for use later */ 151 ctx->sstp0 = sstp0; 152 ctx->sstp1 = sstp1; 153 154 return 0; 155 } 156 157 /* print buffer content as integers when debugging */ 158 void cxl_dump_debug_buffer(void *buf, size_t buf_len) 159 { 160 #ifdef DEBUG 161 int i, *ptr; 162 163 /* 164 * We want to regroup up to 4 integers per line, which means they 165 * need to be in the same pr_devel() statement 166 */ 167 ptr = (int *) buf; 168 for (i = 0; i * 4 < buf_len; i += 4) { 169 if ((i + 3) * 4 < buf_len) 170 pr_devel("%.8x %.8x %.8x %.8x\n", ptr[i], ptr[i + 1], 171 ptr[i + 2], ptr[i + 3]); 172 else if ((i + 2) * 4 < buf_len) 173 pr_devel("%.8x %.8x %.8x\n", ptr[i], ptr[i + 1], 174 ptr[i + 2]); 175 else if ((i + 1) * 4 < buf_len) 176 pr_devel("%.8x %.8x\n", ptr[i], ptr[i + 1]); 177 else 178 pr_devel("%.8x\n", ptr[i]); 179 } 180 #endif /* DEBUG */ 181 } 182 183 /* Find a CXL adapter by it's number and increase it's refcount */ 184 struct cxl *get_cxl_adapter(int num) 185 { 186 struct cxl *adapter; 187 188 spin_lock(&adapter_idr_lock); 189 if ((adapter = idr_find(&cxl_adapter_idr, num))) 190 get_device(&adapter->dev); 191 spin_unlock(&adapter_idr_lock); 192 193 return adapter; 194 } 195 196 static int cxl_alloc_adapter_nr(struct cxl *adapter) 197 { 198 int i; 199 200 idr_preload(GFP_KERNEL); 201 spin_lock(&adapter_idr_lock); 202 i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT); 203 spin_unlock(&adapter_idr_lock); 204 idr_preload_end(); 205 if (i < 0) 206 return i; 207 208 adapter->adapter_num = i; 209 210 return 0; 211 } 212 213 void cxl_remove_adapter_nr(struct cxl *adapter) 214 { 215 idr_remove(&cxl_adapter_idr, adapter->adapter_num); 216 } 217 218 struct cxl *cxl_alloc_adapter(void) 219 { 220 struct cxl *adapter; 221 222 if (!(adapter = kzalloc(sizeof(struct cxl), GFP_KERNEL))) 223 return NULL; 224 225 spin_lock_init(&adapter->afu_list_lock); 226 227 if (cxl_alloc_adapter_nr(adapter)) 228 goto err1; 229 230 if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num)) 231 goto err2; 232 233 /* start with context lock taken */ 234 atomic_set(&adapter->contexts_num, -1); 235 236 return adapter; 237 err2: 238 cxl_remove_adapter_nr(adapter); 239 err1: 240 kfree(adapter); 241 return NULL; 242 } 243 244 struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice) 245 { 246 struct cxl_afu *afu; 247 248 if (!(afu = kzalloc(sizeof(struct cxl_afu), GFP_KERNEL))) 249 return NULL; 250 251 afu->adapter = adapter; 252 afu->dev.parent = &adapter->dev; 253 afu->dev.release = cxl_ops->release_afu; 254 afu->slice = slice; 255 idr_init(&afu->contexts_idr); 256 mutex_init(&afu->contexts_lock); 257 spin_lock_init(&afu->afu_cntl_lock); 258 atomic_set(&afu->configured_state, -1); 259 afu->prefault_mode = CXL_PREFAULT_NONE; 260 afu->irqs_max = afu->adapter->user_irqs; 261 262 return afu; 263 } 264 265 int cxl_afu_select_best_mode(struct cxl_afu *afu) 266 { 267 if (afu->modes_supported & CXL_MODE_DIRECTED) 268 return cxl_ops->afu_activate_mode(afu, CXL_MODE_DIRECTED); 269 270 if (afu->modes_supported & CXL_MODE_DEDICATED) 271 return cxl_ops->afu_activate_mode(afu, CXL_MODE_DEDICATED); 272 273 dev_warn(&afu->dev, "No supported programming modes available\n"); 274 /* We don't fail this so the user can inspect sysfs */ 275 return 0; 276 } 277 278 int cxl_adapter_context_get(struct cxl *adapter) 279 { 280 int rc; 281 282 rc = atomic_inc_unless_negative(&adapter->contexts_num); 283 return rc ? 0 : -EBUSY; 284 } 285 286 void cxl_adapter_context_put(struct cxl *adapter) 287 { 288 atomic_dec_if_positive(&adapter->contexts_num); 289 } 290 291 int cxl_adapter_context_lock(struct cxl *adapter) 292 { 293 int rc; 294 /* no active contexts -> contexts_num == 0 */ 295 rc = atomic_cmpxchg(&adapter->contexts_num, 0, -1); 296 return rc ? -EBUSY : 0; 297 } 298 299 void cxl_adapter_context_unlock(struct cxl *adapter) 300 { 301 int val = atomic_cmpxchg(&adapter->contexts_num, -1, 0); 302 303 /* 304 * contexts lock taken -> contexts_num == -1 305 * If not true then show a warning and force reset the lock. 306 * This will happen when context_unlock was requested without 307 * doing a context_lock. 308 */ 309 if (val != -1) { 310 atomic_set(&adapter->contexts_num, 0); 311 WARN(1, "Adapter context unlocked with %d active contexts", 312 val); 313 } 314 } 315 316 static int __init init_cxl(void) 317 { 318 int rc = 0; 319 320 if (!tlbie_capable) 321 return -EINVAL; 322 323 if ((rc = cxl_file_init())) 324 return rc; 325 326 cxl_debugfs_init(); 327 328 /* 329 * we don't register the callback on P9. slb callack is only 330 * used for the PSL8 MMU and CX4. 331 */ 332 if (cxl_is_power8()) { 333 rc = register_cxl_calls(&cxl_calls); 334 if (rc) 335 goto err; 336 } 337 338 if (cpu_has_feature(CPU_FTR_HVMODE)) { 339 cxl_ops = &cxl_native_ops; 340 rc = pci_register_driver(&cxl_pci_driver); 341 } 342 #ifdef CONFIG_PPC_PSERIES 343 else { 344 cxl_ops = &cxl_guest_ops; 345 rc = platform_driver_register(&cxl_of_driver); 346 } 347 #endif 348 if (rc) 349 goto err1; 350 351 return 0; 352 err1: 353 if (cxl_is_power8()) 354 unregister_cxl_calls(&cxl_calls); 355 err: 356 cxl_debugfs_exit(); 357 cxl_file_exit(); 358 359 return rc; 360 } 361 362 static void exit_cxl(void) 363 { 364 if (cpu_has_feature(CPU_FTR_HVMODE)) 365 pci_unregister_driver(&cxl_pci_driver); 366 #ifdef CONFIG_PPC_PSERIES 367 else 368 platform_driver_unregister(&cxl_of_driver); 369 #endif 370 371 cxl_debugfs_exit(); 372 cxl_file_exit(); 373 if (cxl_is_power8()) 374 unregister_cxl_calls(&cxl_calls); 375 idr_destroy(&cxl_adapter_idr); 376 } 377 378 module_init(init_cxl); 379 module_exit(exit_cxl); 380 381 MODULE_DESCRIPTION("IBM Coherent Accelerator"); 382 MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>"); 383 MODULE_LICENSE("GPL"); 384