drivers/misc/mic/host/mic_smpt.c

   1 /*
   2  * Intel MIC Platform Software Stack (MPSS)
   3  *
   4  * Copyright(c) 2013 Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, version 2, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * The full GNU General Public License is included in this distribution in
  16  * the file called "COPYING".
  17  *
  18  * Intel MIC Host driver.
  19  *
  20  */
  21 #include <linux/pci.h>
  22
  23 #include "../common/mic_dev.h"
  24 #include "mic_device.h"
  25 #include "mic_smpt.h"
  26
  27 static inline u64 mic_system_page_mask(struct mic_device *mdev)
  28 {
  29         return (1ULL << mdev->smpt->info.page_shift) - 1ULL;
  30 }
  31
  32 static inline u8 mic_sys_addr_to_smpt(struct mic_device *mdev, dma_addr_t pa)
  33 {
  34         return (pa - mdev->smpt->info.base) >> mdev->smpt->info.page_shift;
  35 }
  36
  37 static inline u64 mic_smpt_to_pa(struct mic_device *mdev, u8 index)
  38 {
  39         return mdev->smpt->info.base + (index * mdev->smpt->info.page_size);
  40 }
  41
  42 static inline u64 mic_smpt_offset(struct mic_device *mdev, dma_addr_t pa)
  43 {
  44         return pa & mic_system_page_mask(mdev);
  45 }
  46
  47 static inline u64 mic_smpt_align_low(struct mic_device *mdev, dma_addr_t pa)
  48 {
  49         return ALIGN(pa - mic_system_page_mask(mdev),
  50                 mdev->smpt->info.page_size);
  51 }
  52
  53 static inline u64 mic_smpt_align_high(struct mic_device *mdev, dma_addr_t pa)
  54 {
  55         return ALIGN(pa, mdev->smpt->info.page_size);
  56 }
  57
  58 /* Total Cumulative system memory accessible by MIC across all SMPT entries */
  59 static inline u64 mic_max_system_memory(struct mic_device *mdev)
  60 {
  61         return mdev->smpt->info.num_reg * mdev->smpt->info.page_size;
  62 }
  63
  64 /* Maximum system memory address accessible by MIC */
  65 static inline u64 mic_max_system_addr(struct mic_device *mdev)
  66 {
  67         return mdev->smpt->info.base + mic_max_system_memory(mdev) - 1ULL;
  68 }
  69
  70 /* Check if the DMA address is a MIC system memory address */
  71 static inline bool
  72 mic_is_system_addr(struct mic_device *mdev, dma_addr_t pa)
  73 {
  74         return pa >= mdev->smpt->info.base && pa <= mic_max_system_addr(mdev);
  75 }
  76
  77 /* Populate an SMPT entry and update the reference counts. */
  78 static void mic_add_smpt_entry(int spt, s64 *ref, u64 addr,
  79                                int entries, struct mic_device *mdev)
  80 {
  81         struct mic_smpt_info *smpt_info = mdev->smpt;
  82         int i;
  83
  84         for (i = spt; i < spt + entries; i++,
  85                 addr += smpt_info->info.page_size) {
  86                 if (!smpt_info->entry[i].ref_count &&
  87                     (smpt_info->entry[i].dma_addr != addr)) {
  88                         mdev->smpt_ops->set(mdev, addr, i);
  89                         smpt_info->entry[i].dma_addr = addr;
  90                 }
  91                 smpt_info->entry[i].ref_count += ref[i - spt];
  92         }
  93 }
  94
  95 /*
  96  * Find an available MIC address in MIC SMPT address space
  97  * for a given DMA address and size.
  98  */
  99 static dma_addr_t mic_smpt_op(struct mic_device *mdev, u64 dma_addr,
 100                               int entries, s64 *ref, size_t size)
 101 {
 102         int spt;
 103         int ae = 0;
 104         int i;
 105         unsigned long flags;
 106         dma_addr_t mic_addr = 0;
 107         dma_addr_t addr = dma_addr;
 108         struct mic_smpt_info *smpt_info = mdev->smpt;
 109
 110         spin_lock_irqsave(&smpt_info->smpt_lock, flags);
 111
 112         /* find existing entries */
 113         for (i = 0; i < smpt_info->info.num_reg; i++) {
 114                 if (smpt_info->entry[i].dma_addr == addr) {
 115                         ae++;
 116                         addr += smpt_info->info.page_size;
 117                 } else if (ae) /* cannot find contiguous entries */
 118                         goto not_found;
 119
 120                 if (ae == entries)
 121                         goto found;
 122         }
 123
 124         /* find free entry */
 125         for (ae = 0, i = 0; i < smpt_info->info.num_reg; i++) {
 126                 ae = (smpt_info->entry[i].ref_count == 0) ? ae + 1 : 0;
 127                 if (ae == entries)
 128                         goto found;
 129         }
 130
 131 not_found:
 132         spin_unlock_irqrestore(&smpt_info->smpt_lock, flags);
 133         return mic_addr;
 134
 135 found:
 136         spt = i - entries + 1;
 137         mic_addr = mic_smpt_to_pa(mdev, spt);
 138         mic_add_smpt_entry(spt, ref, dma_addr, entries, mdev);
 139         smpt_info->map_count++;
 140         smpt_info->ref_count += (s64)size;
 141         spin_unlock_irqrestore(&smpt_info->smpt_lock, flags);
 142         return mic_addr;
 143 }
 144
 145 /*
 146  * Returns number of smpt entries needed for dma_addr to dma_addr + size
 147  * also returns the reference count array for each of those entries
 148  * and the starting smpt address
 149  */
 150 static int mic_get_smpt_ref_count(struct mic_device *mdev, dma_addr_t dma_addr,
 151                                   size_t size, s64 *ref,  u64 *smpt_start)
 152 {
 153         u64 start =  dma_addr;
 154         u64 end = dma_addr + size;
 155         int i = 0;
 156
 157         while (start < end) {
 158                 ref[i++] = min(mic_smpt_align_high(mdev, start + 1),
 159                         end) - start;
 160                 start = mic_smpt_align_high(mdev, start + 1);
 161         }
 162
 163         if (smpt_start)
 164                 *smpt_start = mic_smpt_align_low(mdev, dma_addr);
 165
 166         return i;
 167 }
 168
 169 /*
 170  * mic_to_dma_addr - Converts a MIC address to a DMA address.
 171  *
 172  * @mdev: pointer to mic_device instance.
 173  * @mic_addr: MIC address.
 174  *
 175  * returns a DMA address.
 176  */
 177 dma_addr_t mic_to_dma_addr(struct mic_device *mdev, dma_addr_t mic_addr)
 178 {
 179         struct mic_smpt_info *smpt_info = mdev->smpt;
 180         int spt;
 181         dma_addr_t dma_addr;
 182
 183         if (!mic_is_system_addr(mdev, mic_addr)) {
 184                 dev_err(&mdev->pdev->dev,
 185                         "mic_addr is invalid. mic_addr = 0x%llx\n", mic_addr);
 186                 return -EINVAL;
 187         }
 188         spt = mic_sys_addr_to_smpt(mdev, mic_addr);
 189         dma_addr = smpt_info->entry[spt].dma_addr +
 190                 mic_smpt_offset(mdev, mic_addr);
 191         return dma_addr;
 192 }
 193
 194 /**
 195  * mic_map - Maps a DMA address to a MIC physical address.
 196  *
 197  * @mdev: pointer to mic_device instance.
 198  * @dma_addr: DMA address.
 199  * @size: Size of the region to be mapped.
 200  *
 201  * This API converts the DMA address provided to a DMA address understood
 202  * by MIC. Caller should check for errors by calling mic_map_error(..).
 203  *
 204  * returns DMA address as required by MIC.
 205  */
 206 dma_addr_t mic_map(struct mic_device *mdev, dma_addr_t dma_addr, size_t size)
 207 {
 208         dma_addr_t mic_addr = 0;
 209         int num_entries;
 210         s64 *ref;
 211         u64 smpt_start;
 212
 213         if (!size || size > mic_max_system_memory(mdev))
 214                 return mic_addr;
 215
 216         ref = kmalloc_array(mdev->smpt->info.num_reg, sizeof(s64), GFP_ATOMIC);
 217         if (!ref)
 218                 return mic_addr;
 219
 220         num_entries = mic_get_smpt_ref_count(mdev, dma_addr, size,
 221                                              ref, &smpt_start);
 222
 223         /* Set the smpt table appropriately and get 16G aligned mic address */
 224         mic_addr = mic_smpt_op(mdev, smpt_start, num_entries, ref, size);
 225
 226         kfree(ref);
 227
 228         /*
 229          * If mic_addr is zero then its an error case
 230          * since mic_addr can never be zero.
 231          * else generate mic_addr by adding the 16G offset in dma_addr
 232          */
 233         if (!mic_addr && MIC_FAMILY_X100 == mdev->family) {
 234                 dev_err(&mdev->pdev->dev,
 235                         "mic_map failed dma_addr 0x%llx size 0x%lx\n",
 236                         dma_addr, size);
 237                 return mic_addr;
 238         } else {
 239                 return mic_addr + mic_smpt_offset(mdev, dma_addr);
 240         }
 241 }
 242
 243 /**
 244  * mic_unmap - Unmaps a MIC physical address.
 245  *
 246  * @mdev: pointer to mic_device instance.
 247  * @mic_addr: MIC physical address.
 248  * @size: Size of the region to be unmapped.
 249  *
 250  * This API unmaps the mappings created by mic_map(..).
 251  *
 252  * returns None.
 253  */
 254 void mic_unmap(struct mic_device *mdev, dma_addr_t mic_addr, size_t size)
 255 {
 256         struct mic_smpt_info *smpt_info = mdev->smpt;
 257         s64 *ref;
 258         int num_smpt;
 259         int spt;
 260         int i;
 261         unsigned long flags;
 262
 263         if (!size)
 264                 return;
 265
 266         if (!mic_is_system_addr(mdev, mic_addr)) {
 267                 dev_err(&mdev->pdev->dev,
 268                         "invalid address: 0x%llx\n", mic_addr);
 269                 return;
 270         }
 271
 272         spt = mic_sys_addr_to_smpt(mdev, mic_addr);
 273         ref = kmalloc_array(mdev->smpt->info.num_reg, sizeof(s64), GFP_ATOMIC);
 274         if (!ref)
 275                 return;
 276
 277         /* Get number of smpt entries to be mapped, ref count array */
 278         num_smpt = mic_get_smpt_ref_count(mdev, mic_addr, size, ref, NULL);
 279
 280         spin_lock_irqsave(&smpt_info->smpt_lock, flags);
 281         smpt_info->unmap_count++;
 282         smpt_info->ref_count -= (s64)size;
 283
 284         for (i = spt; i < spt + num_smpt; i++) {
 285                 smpt_info->entry[i].ref_count -= ref[i - spt];
 286                 if (smpt_info->entry[i].ref_count < 0)
 287                         dev_warn(&mdev->pdev->dev,
 288                                  "ref count for entry %d is negative\n", i);
 289         }
 290         spin_unlock_irqrestore(&smpt_info->smpt_lock, flags);
 291         kfree(ref);
 292 }
 293
 294 /**
 295  * mic_map_single - Maps a virtual address to a MIC physical address.
 296  *
 297  * @mdev: pointer to mic_device instance.
 298  * @va: Kernel direct mapped virtual address.
 299  * @size: Size of the region to be mapped.
 300  *
 301  * This API calls pci_map_single(..) for the direct mapped virtual address
 302  * and then converts the DMA address provided to a DMA address understood
 303  * by MIC. Caller should check for errors by calling mic_map_error(..).
 304  *
 305  * returns DMA address as required by MIC.
 306  */
 307 dma_addr_t mic_map_single(struct mic_device *mdev, void *va, size_t size)
 308 {
 309         dma_addr_t mic_addr = 0;
 310         struct pci_dev *pdev = mdev->pdev;
 311         dma_addr_t dma_addr =
 312                 pci_map_single(pdev, va, size, PCI_DMA_BIDIRECTIONAL);
 313
 314         if (!pci_dma_mapping_error(pdev, dma_addr)) {
 315                 mic_addr = mic_map(mdev, dma_addr, size);
 316                 if (!mic_addr) {
 317                         dev_err(&mdev->pdev->dev,
 318                                 "mic_map failed dma_addr 0x%llx size 0x%lx\n",
 319                                 dma_addr, size);
 320                         pci_unmap_single(pdev, dma_addr,
 321                                          size, PCI_DMA_BIDIRECTIONAL);
 322                 }
 323         }
 324         return mic_addr;
 325 }
 326
 327 /**
 328  * mic_unmap_single - Unmaps a MIC physical address.
 329  *
 330  * @mdev: pointer to mic_device instance.
 331  * @mic_addr: MIC physical address.
 332  * @size: Size of the region to be unmapped.
 333  *
 334  * This API unmaps the mappings created by mic_map_single(..).
 335  *
 336  * returns None.
 337  */
 338 void
 339 mic_unmap_single(struct mic_device *mdev, dma_addr_t mic_addr, size_t size)
 340 {
 341         struct pci_dev *pdev = mdev->pdev;
 342         dma_addr_t dma_addr = mic_to_dma_addr(mdev, mic_addr);
 343         mic_unmap(mdev, mic_addr, size);
 344         pci_unmap_single(pdev, dma_addr, size, PCI_DMA_BIDIRECTIONAL);
 345 }
 346
 347 /**
 348  * mic_smpt_init - Initialize MIC System Memory Page Tables.
 349  *
 350  * @mdev: pointer to mic_device instance.
 351  *
 352  * returns 0 for success and -errno for error.
 353  */
 354 int mic_smpt_init(struct mic_device *mdev)
 355 {
 356         int i, err = 0;
 357         dma_addr_t dma_addr;
 358         struct mic_smpt_info *smpt_info;
 359
 360         mdev->smpt = kmalloc(sizeof(*mdev->smpt), GFP_KERNEL);
 361         if (!mdev->smpt)
 362                 return -ENOMEM;
 363
 364         smpt_info = mdev->smpt;
 365         mdev->smpt_ops->init(mdev);
 366         smpt_info->entry = kmalloc_array(smpt_info->info.num_reg,
 367                                          sizeof(*smpt_info->entry), GFP_KERNEL);
 368         if (!smpt_info->entry) {
 369                 err = -ENOMEM;
 370                 goto free_smpt;
 371         }
 372         spin_lock_init(&smpt_info->smpt_lock);
 373         for (i = 0; i < smpt_info->info.num_reg; i++) {
 374                 dma_addr = i * smpt_info->info.page_size;
 375                 smpt_info->entry[i].dma_addr = dma_addr;
 376                 smpt_info->entry[i].ref_count = 0;
 377                 mdev->smpt_ops->set(mdev, dma_addr, i);
 378         }
 379         smpt_info->ref_count = 0;
 380         smpt_info->map_count = 0;
 381         smpt_info->unmap_count = 0;
 382         return 0;
 383 free_smpt:
 384         kfree(smpt_info);
 385         return err;
 386 }
 387
 388 /**
 389  * mic_smpt_uninit - UnInitialize MIC System Memory Page Tables.
 390  *
 391  * @mdev: pointer to mic_device instance.
 392  *
 393  * returns None.
 394  */
 395 void mic_smpt_uninit(struct mic_device *mdev)
 396 {
 397         struct mic_smpt_info *smpt_info = mdev->smpt;
 398         int i;
 399
 400         dev_dbg(&mdev->pdev->dev,
 401                 "nodeid %d SMPT ref count %lld map %lld unmap %lld\n",
 402                 mdev->id, smpt_info->ref_count,
 403                 smpt_info->map_count, smpt_info->unmap_count);
 404
 405         for (i = 0; i < smpt_info->info.num_reg; i++) {
 406                 dev_dbg(&mdev->pdev->dev,
 407                         "SMPT entry[%d] dma_addr = 0x%llx ref_count = %lld\n",
 408                         i, smpt_info->entry[i].dma_addr,
 409                         smpt_info->entry[i].ref_count);
 410                 if (smpt_info->entry[i].ref_count)
 411                         dev_warn(&mdev->pdev->dev,
 412                                  "ref count for entry %d is not zero\n", i);
 413         }
 414         kfree(smpt_info->entry);
 415         kfree(smpt_info);
 416 }
 417
 418 /**
 419  * mic_smpt_restore - Restore MIC System Memory Page Tables.
 420  *
 421  * @mdev: pointer to mic_device instance.
 422  *
 423  * Restore the SMPT registers to values previously stored in the
 424  * SW data structures. Some MIC steppings lose register state
 425  * across resets and this API should be called for performing
 426  * a restore operation if required.
 427  *
 428  * returns None.
 429  */
 430 void mic_smpt_restore(struct mic_device *mdev)
 431 {
 432         int i;
 433         dma_addr_t dma_addr;
 434
 435         for (i = 0; i < mdev->smpt->info.num_reg; i++) {
 436                 dma_addr = mdev->smpt->entry[i].dma_addr;
 437                 mdev->smpt_ops->set(mdev, dma_addr, i);
 438         }
 439 }