1 /* 2 * Copyright 2014 IBM Corp. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 */ 9 10 #include <linux/spinlock.h> 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/device.h> 14 #include <linux/mutex.h> 15 #include <linux/init.h> 16 #include <linux/list.h> 17 #include <linux/mm.h> 18 #include <linux/of.h> 19 #include <linux/slab.h> 20 #include <linux/idr.h> 21 #include <linux/pci.h> 22 #include <asm/cputable.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 struct task_struct *task; 61 unsigned long flags; 62 if (!(task = get_pid_task(ctx->pid, PIDTYPE_PID))) { 63 pr_devel("%s unable to get task %i\n", 64 __func__, pid_nr(ctx->pid)); 65 return; 66 } 67 68 if (task->mm != mm) 69 goto out_put; 70 71 pr_devel("%s matched mm - card: %i afu: %i pe: %i\n", __func__, 72 ctx->afu->adapter->adapter_num, ctx->afu->slice, ctx->pe); 73 74 spin_lock_irqsave(&ctx->sste_lock, flags); 75 trace_cxl_slbia(ctx); 76 memset(ctx->sstp, 0, ctx->sst_size); 77 spin_unlock_irqrestore(&ctx->sste_lock, flags); 78 mb(); 79 cxl_afu_slbia(ctx->afu); 80 out_put: 81 put_task_struct(task); 82 } 83 84 static inline void cxl_slbia_core(struct mm_struct *mm) 85 { 86 struct cxl *adapter; 87 struct cxl_afu *afu; 88 struct cxl_context *ctx; 89 int card, slice, id; 90 91 pr_devel("%s called\n", __func__); 92 93 spin_lock(&adapter_idr_lock); 94 idr_for_each_entry(&cxl_adapter_idr, adapter, card) { 95 /* XXX: Make this lookup faster with link from mm to ctx */ 96 spin_lock(&adapter->afu_list_lock); 97 for (slice = 0; slice < adapter->slices; slice++) { 98 afu = adapter->afu[slice]; 99 if (!afu || !afu->enabled) 100 continue; 101 rcu_read_lock(); 102 idr_for_each_entry(&afu->contexts_idr, ctx, id) 103 _cxl_slbia(ctx, mm); 104 rcu_read_unlock(); 105 } 106 spin_unlock(&adapter->afu_list_lock); 107 } 108 spin_unlock(&adapter_idr_lock); 109 } 110 111 static struct cxl_calls cxl_calls = { 112 .cxl_slbia = cxl_slbia_core, 113 .cxl_pci_associate_default_context = _cxl_pci_associate_default_context, 114 .cxl_pci_disable_device = _cxl_pci_disable_device, 115 .cxl_next_msi_hwirq = _cxl_next_msi_hwirq, 116 .cxl_cx4_setup_msi_irqs = _cxl_cx4_setup_msi_irqs, 117 .cxl_cx4_teardown_msi_irqs = _cxl_cx4_teardown_msi_irqs, 118 .owner = THIS_MODULE, 119 }; 120 121 int cxl_alloc_sst(struct cxl_context *ctx) 122 { 123 unsigned long vsid; 124 u64 ea_mask, size, sstp0, sstp1; 125 126 sstp0 = 0; 127 sstp1 = 0; 128 129 ctx->sst_size = PAGE_SIZE; 130 ctx->sst_lru = 0; 131 ctx->sstp = (struct cxl_sste *)get_zeroed_page(GFP_KERNEL); 132 if (!ctx->sstp) { 133 pr_err("cxl_alloc_sst: Unable to allocate segment table\n"); 134 return -ENOMEM; 135 } 136 pr_devel("SSTP allocated at 0x%p\n", ctx->sstp); 137 138 vsid = get_kernel_vsid((u64)ctx->sstp, mmu_kernel_ssize) << 12; 139 140 sstp0 |= (u64)mmu_kernel_ssize << CXL_SSTP0_An_B_SHIFT; 141 sstp0 |= (SLB_VSID_KERNEL | mmu_psize_defs[mmu_linear_psize].sllp) << 50; 142 143 size = (((u64)ctx->sst_size >> 8) - 1) << CXL_SSTP0_An_SegTableSize_SHIFT; 144 if (unlikely(size & ~CXL_SSTP0_An_SegTableSize_MASK)) { 145 WARN(1, "Impossible segment table size\n"); 146 return -EINVAL; 147 } 148 sstp0 |= size; 149 150 if (mmu_kernel_ssize == MMU_SEGSIZE_256M) 151 ea_mask = 0xfffff00ULL; 152 else 153 ea_mask = 0xffffffff00ULL; 154 155 sstp0 |= vsid >> (50-14); /* Top 14 bits of VSID */ 156 sstp1 |= (vsid << (64-(50-14))) & ~ea_mask; 157 sstp1 |= (u64)ctx->sstp & ea_mask; 158 sstp1 |= CXL_SSTP1_An_V; 159 160 pr_devel("Looked up %#llx: slbfee. %#llx (ssize: %x, vsid: %#lx), copied to SSTP0: %#llx, SSTP1: %#llx\n", 161 (u64)ctx->sstp, (u64)ctx->sstp & ESID_MASK, mmu_kernel_ssize, vsid, sstp0, sstp1); 162 163 /* Store calculated sstp hardware points for use later */ 164 ctx->sstp0 = sstp0; 165 ctx->sstp1 = sstp1; 166 167 return 0; 168 } 169 170 /* print buffer content as integers when debugging */ 171 void cxl_dump_debug_buffer(void *buf, size_t buf_len) 172 { 173 #ifdef DEBUG 174 int i, *ptr; 175 176 /* 177 * We want to regroup up to 4 integers per line, which means they 178 * need to be in the same pr_devel() statement 179 */ 180 ptr = (int *) buf; 181 for (i = 0; i * 4 < buf_len; i += 4) { 182 if ((i + 3) * 4 < buf_len) 183 pr_devel("%.8x %.8x %.8x %.8x\n", ptr[i], ptr[i + 1], 184 ptr[i + 2], ptr[i + 3]); 185 else if ((i + 2) * 4 < buf_len) 186 pr_devel("%.8x %.8x %.8x\n", ptr[i], ptr[i + 1], 187 ptr[i + 2]); 188 else if ((i + 1) * 4 < buf_len) 189 pr_devel("%.8x %.8x\n", ptr[i], ptr[i + 1]); 190 else 191 pr_devel("%.8x\n", ptr[i]); 192 } 193 #endif /* DEBUG */ 194 } 195 196 /* Find a CXL adapter by it's number and increase it's refcount */ 197 struct cxl *get_cxl_adapter(int num) 198 { 199 struct cxl *adapter; 200 201 spin_lock(&adapter_idr_lock); 202 if ((adapter = idr_find(&cxl_adapter_idr, num))) 203 get_device(&adapter->dev); 204 spin_unlock(&adapter_idr_lock); 205 206 return adapter; 207 } 208 209 static int cxl_alloc_adapter_nr(struct cxl *adapter) 210 { 211 int i; 212 213 idr_preload(GFP_KERNEL); 214 spin_lock(&adapter_idr_lock); 215 i = idr_alloc(&cxl_adapter_idr, adapter, 0, 0, GFP_NOWAIT); 216 spin_unlock(&adapter_idr_lock); 217 idr_preload_end(); 218 if (i < 0) 219 return i; 220 221 adapter->adapter_num = i; 222 223 return 0; 224 } 225 226 void cxl_remove_adapter_nr(struct cxl *adapter) 227 { 228 idr_remove(&cxl_adapter_idr, adapter->adapter_num); 229 } 230 231 struct cxl *cxl_alloc_adapter(void) 232 { 233 struct cxl *adapter; 234 235 if (!(adapter = kzalloc(sizeof(struct cxl), GFP_KERNEL))) 236 return NULL; 237 238 spin_lock_init(&adapter->afu_list_lock); 239 240 if (cxl_alloc_adapter_nr(adapter)) 241 goto err1; 242 243 if (dev_set_name(&adapter->dev, "card%i", adapter->adapter_num)) 244 goto err2; 245 246 /* start with context lock taken */ 247 atomic_set(&adapter->contexts_num, -1); 248 249 return adapter; 250 err2: 251 cxl_remove_adapter_nr(adapter); 252 err1: 253 kfree(adapter); 254 return NULL; 255 } 256 257 struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice) 258 { 259 struct cxl_afu *afu; 260 261 if (!(afu = kzalloc(sizeof(struct cxl_afu), GFP_KERNEL))) 262 return NULL; 263 264 afu->adapter = adapter; 265 afu->dev.parent = &adapter->dev; 266 afu->dev.release = cxl_ops->release_afu; 267 afu->slice = slice; 268 idr_init(&afu->contexts_idr); 269 mutex_init(&afu->contexts_lock); 270 spin_lock_init(&afu->afu_cntl_lock); 271 272 afu->prefault_mode = CXL_PREFAULT_NONE; 273 afu->irqs_max = afu->adapter->user_irqs; 274 275 return afu; 276 } 277 278 int cxl_afu_select_best_mode(struct cxl_afu *afu) 279 { 280 if (afu->modes_supported & CXL_MODE_DIRECTED) 281 return cxl_ops->afu_activate_mode(afu, CXL_MODE_DIRECTED); 282 283 if (afu->modes_supported & CXL_MODE_DEDICATED) 284 return cxl_ops->afu_activate_mode(afu, CXL_MODE_DEDICATED); 285 286 dev_warn(&afu->dev, "No supported programming modes available\n"); 287 /* We don't fail this so the user can inspect sysfs */ 288 return 0; 289 } 290 291 int cxl_adapter_context_get(struct cxl *adapter) 292 { 293 int rc; 294 295 rc = atomic_inc_unless_negative(&adapter->contexts_num); 296 return rc >= 0 ? 0 : -EBUSY; 297 } 298 299 void cxl_adapter_context_put(struct cxl *adapter) 300 { 301 atomic_dec_if_positive(&adapter->contexts_num); 302 } 303 304 int cxl_adapter_context_lock(struct cxl *adapter) 305 { 306 int rc; 307 /* no active contexts -> contexts_num == 0 */ 308 rc = atomic_cmpxchg(&adapter->contexts_num, 0, -1); 309 return rc ? -EBUSY : 0; 310 } 311 312 void cxl_adapter_context_unlock(struct cxl *adapter) 313 { 314 int val = atomic_cmpxchg(&adapter->contexts_num, -1, 0); 315 316 /* 317 * contexts lock taken -> contexts_num == -1 318 * If not true then show a warning and force reset the lock. 319 * This will happen when context_unlock was requested without 320 * doing a context_lock. 321 */ 322 if (val != -1) { 323 atomic_set(&adapter->contexts_num, 0); 324 WARN(1, "Adapter context unlocked with %d active contexts", 325 val); 326 } 327 } 328 329 static int __init init_cxl(void) 330 { 331 int rc = 0; 332 333 if ((rc = cxl_file_init())) 334 return rc; 335 336 cxl_debugfs_init(); 337 338 if ((rc = register_cxl_calls(&cxl_calls))) 339 goto err; 340 341 if (cpu_has_feature(CPU_FTR_HVMODE)) { 342 cxl_ops = &cxl_native_ops; 343 rc = pci_register_driver(&cxl_pci_driver); 344 } 345 #ifdef CONFIG_PPC_PSERIES 346 else { 347 cxl_ops = &cxl_guest_ops; 348 rc = platform_driver_register(&cxl_of_driver); 349 } 350 #endif 351 if (rc) 352 goto err1; 353 354 return 0; 355 err1: 356 unregister_cxl_calls(&cxl_calls); 357 err: 358 cxl_debugfs_exit(); 359 cxl_file_exit(); 360 361 return rc; 362 } 363 364 static void exit_cxl(void) 365 { 366 if (cpu_has_feature(CPU_FTR_HVMODE)) 367 pci_unregister_driver(&cxl_pci_driver); 368 #ifdef CONFIG_PPC_PSERIES 369 else 370 platform_driver_unregister(&cxl_of_driver); 371 #endif 372 373 cxl_debugfs_exit(); 374 cxl_file_exit(); 375 unregister_cxl_calls(&cxl_calls); 376 idr_destroy(&cxl_adapter_idr); 377 } 378 379 module_init(init_cxl); 380 module_exit(exit_cxl); 381 382 MODULE_DESCRIPTION("IBM Coherent Accelerator"); 383 MODULE_AUTHOR("Ian Munsie <imunsie@au1.ibm.com>"); 384 MODULE_LICENSE("GPL"); 385