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/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");