drivers/misc/cxl/main.c

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