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 <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         atomic_set(&afu->configured_state, -1);
 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");