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