drivers/misc/cxl/main.c

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