arch/sh/kernel/cpu/sh4/sq.c

   1 /*
   2  * arch/sh/kernel/cpu/sh4/sq.c
   3  *
   4  * General management API for SH-4 integrated Store Queues
   5  *
   6  * Copyright (C) 2001 - 2006  Paul Mundt
   7  * Copyright (C) 2001, 2002  M. R. Brown
   8  *
   9  * This file is subject to the terms and conditions of the GNU General Public
  10  * License.  See the file "COPYING" in the main directory of this archive
  11  * for more details.
  12  */
  13 #include <linux/init.h>
  14 #include <linux/cpu.h>
  15 #include <linux/bitmap.h>
  16 #include <linux/sysdev.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/slab.h>
  20 #include <linux/vmalloc.h>
  21 #include <linux/mm.h>
  22 #include <linux/io.h>
  23 #include <asm/page.h>
  24 #include <asm/cacheflush.h>
  25 #include <asm/cpu/sq.h>
  26
  27 struct sq_mapping;
  28
  29 struct sq_mapping {
  30         const char *name;
  31
  32         unsigned long sq_addr;
  33         unsigned long addr;
  34         unsigned int size;
  35
  36         struct sq_mapping *next;
  37 };
  38
  39 static struct sq_mapping *sq_mapping_list;
  40 static DEFINE_SPINLOCK(sq_mapping_lock);
  41 static struct kmem_cache *sq_cache;
  42 static unsigned long *sq_bitmap;
  43
  44 #define store_queue_barrier()                   \
  45 do {                                            \
  46         (void)ctrl_inl(P4SEG_STORE_QUE);        \
  47         ctrl_outl(0, P4SEG_STORE_QUE + 0);      \
  48         ctrl_outl(0, P4SEG_STORE_QUE + 8);      \
  49 } while (0);
  50
  51 /**
  52  * sq_flush_range - Flush (prefetch) a specific SQ range
  53  * @start: the store queue address to start flushing from
  54  * @len: the length to flush
  55  *
  56  * Flushes the store queue cache from @start to @start + @len in a
  57  * linear fashion.
  58  */
  59 void sq_flush_range(unsigned long start, unsigned int len)
  60 {
  61         volatile unsigned long *sq = (unsigned long *)start;
  62
  63         /* Flush the queues */
  64         for (len >>= 5; len--; sq += 8)
  65                 prefetchw((void *)sq);
  66
  67         /* Wait for completion */
  68         store_queue_barrier();
  69 }
  70 EXPORT_SYMBOL(sq_flush_range);
  71
  72 static inline void sq_mapping_list_add(struct sq_mapping *map)
  73 {
  74         struct sq_mapping **p, *tmp;
  75
  76         spin_lock_irq(&sq_mapping_lock);
  77
  78         p = &sq_mapping_list;
  79         while ((tmp = *p) != NULL)
  80                 p = &tmp->next;
  81
  82         map->next = tmp;
  83         *p = map;
  84
  85         spin_unlock_irq(&sq_mapping_lock);
  86 }
  87
  88 static inline void sq_mapping_list_del(struct sq_mapping *map)
  89 {
  90         struct sq_mapping **p, *tmp;
  91
  92         spin_lock_irq(&sq_mapping_lock);
  93
  94         for (p = &sq_mapping_list; (tmp = *p); p = &tmp->next)
  95                 if (tmp == map) {
  96                         *p = tmp->next;
  97                         break;
  98                 }
  99
 100         spin_unlock_irq(&sq_mapping_lock);
 101 }
 102
 103 static int __sq_remap(struct sq_mapping *map, unsigned long flags)
 104 {
 105 #if defined(CONFIG_MMU)
 106         struct vm_struct *vma;
 107
 108         vma = __get_vm_area(map->size, VM_ALLOC, map->sq_addr, SQ_ADDRMAX);
 109         if (!vma)
 110                 return -ENOMEM;
 111
 112         vma->phys_addr = map->addr;
 113
 114         if (remap_area_pages((unsigned long)vma->addr, vma->phys_addr,
 115                              map->size, flags)) {
 116                 vunmap(vma->addr);
 117                 return -EAGAIN;
 118         }
 119 #else
 120         /*
 121          * Without an MMU (or with it turned off), this is much more
 122          * straightforward, as we can just load up each queue's QACR with
 123          * the physical address appropriately masked.
 124          */
 125         ctrl_outl(((map->addr >> 26) << 2) & 0x1c, SQ_QACR0);
 126         ctrl_outl(((map->addr >> 26) << 2) & 0x1c, SQ_QACR1);
 127 #endif
 128
 129         return 0;
 130 }
 131
 132 /**
 133  * sq_remap - Map a physical address through the Store Queues
 134  * @phys: Physical address of mapping.
 135  * @size: Length of mapping.
 136  * @name: User invoking mapping.
 137  * @flags: Protection flags.
 138  *
 139  * Remaps the physical address @phys through the next available store queue
 140  * address of @size length. @name is logged at boot time as well as through
 141  * the sysfs interface.
 142  */
 143 unsigned long sq_remap(unsigned long phys, unsigned int size,
 144                        const char *name, unsigned long flags)
 145 {
 146         struct sq_mapping *map;
 147         unsigned long end;
 148         unsigned int psz;
 149         int ret, page;
 150
 151         /* Don't allow wraparound or zero size */
 152         end = phys + size - 1;
 153         if (unlikely(!size || end < phys))
 154                 return -EINVAL;
 155         /* Don't allow anyone to remap normal memory.. */
 156         if (unlikely(phys < virt_to_phys(high_memory)))
 157                 return -EINVAL;
 158
 159         phys &= PAGE_MASK;
 160         size = PAGE_ALIGN(end + 1) - phys;
 161
 162         map = kmem_cache_alloc(sq_cache, GFP_KERNEL);
 163         if (unlikely(!map))
 164                 return -ENOMEM;
 165
 166         map->addr = phys;
 167         map->size = size;
 168         map->name = name;
 169
 170         page = bitmap_find_free_region(sq_bitmap, 0x04000000 >> PAGE_SHIFT,
 171                                        get_order(map->size));
 172         if (unlikely(page < 0)) {
 173                 ret = -ENOSPC;
 174                 goto out;
 175         }
 176
 177         map->sq_addr = P4SEG_STORE_QUE + (page << PAGE_SHIFT);
 178
 179         ret = __sq_remap(map, flags);
 180         if (unlikely(ret != 0))
 181                 goto out;
 182
 183         psz = (size + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
 184         pr_info("sqremap: %15s  [%4d page%s]  va 0x%08lx   pa 0x%08lx\n",
 185                 likely(map->name) ? map->name : "???",
 186                 psz, psz == 1 ? " " : "s",
 187                 map->sq_addr, map->addr);
 188
 189         sq_mapping_list_add(map);
 190
 191         return map->sq_addr;
 192
 193 out:
 194         kmem_cache_free(sq_cache, map);
 195         return ret;
 196 }
 197 EXPORT_SYMBOL(sq_remap);
 198
 199 /**
 200  * sq_unmap - Unmap a Store Queue allocation
 201  * @map: Pre-allocated Store Queue mapping.
 202  *
 203  * Unmaps the store queue allocation @map that was previously created by
 204  * sq_remap(). Also frees up the pte that was previously inserted into
 205  * the kernel page table and discards the UTLB translation.
 206  */
 207 void sq_unmap(unsigned long vaddr)
 208 {
 209         struct sq_mapping **p, *map;
 210         struct vm_struct *vma;
 211         int page;
 212
 213         for (p = &sq_mapping_list; (map = *p); p = &map->next)
 214                 if (map->sq_addr == vaddr)
 215                         break;
 216
 217         if (unlikely(!map)) {
 218                 printk("%s: bad store queue address 0x%08lx\n",
 219                        __FUNCTION__, vaddr);
 220                 return;
 221         }
 222
 223         page = (map->sq_addr - P4SEG_STORE_QUE) >> PAGE_SHIFT;
 224         bitmap_release_region(sq_bitmap, page, get_order(map->size));
 225
 226 #ifdef CONFIG_MMU
 227         vma = remove_vm_area((void *)(map->sq_addr & PAGE_MASK));
 228         if (!vma) {
 229                 printk(KERN_ERR "%s: bad address 0x%08lx\n",
 230                        __FUNCTION__, map->sq_addr);
 231                 return;
 232         }
 233 #endif
 234
 235         sq_mapping_list_del(map);
 236
 237         kmem_cache_free(sq_cache, map);
 238 }
 239 EXPORT_SYMBOL(sq_unmap);
 240
 241 /*
 242  * Needlessly complex sysfs interface. Unfortunately it doesn't seem like
 243  * there is any other easy way to add things on a per-cpu basis without
 244  * putting the directory entries somewhere stupid and having to create
 245  * links in sysfs by hand back in to the per-cpu directories.
 246  *
 247  * Some day we may want to have an additional abstraction per store
 248  * queue, but considering the kobject hell we already have to deal with,
 249  * it's simply not worth the trouble.
 250  */
 251 static struct kobject *sq_kobject[NR_CPUS];
 252
 253 struct sq_sysfs_attr {
 254         struct attribute attr;
 255         ssize_t (*show)(char *buf);
 256         ssize_t (*store)(const char *buf, size_t count);
 257 };
 258
 259 #define to_sq_sysfs_attr(attr)  container_of(attr, struct sq_sysfs_attr, attr)
 260
 261 static ssize_t sq_sysfs_show(struct kobject *kobj, struct attribute *attr,
 262                              char *buf)
 263 {
 264         struct sq_sysfs_attr *sattr = to_sq_sysfs_attr(attr);
 265
 266         if (likely(sattr->show))
 267                 return sattr->show(buf);
 268
 269         return -EIO;
 270 }
 271
 272 static ssize_t sq_sysfs_store(struct kobject *kobj, struct attribute *attr,
 273                               const char *buf, size_t count)
 274 {
 275         struct sq_sysfs_attr *sattr = to_sq_sysfs_attr(attr);
 276
 277         if (likely(sattr->store))
 278                 return sattr->store(buf, count);
 279
 280         return -EIO;
 281 }
 282
 283 static ssize_t mapping_show(char *buf)
 284 {
 285         struct sq_mapping **list, *entry;
 286         char *p = buf;
 287
 288         for (list = &sq_mapping_list; (entry = *list); list = &entry->next)
 289                 p += sprintf(p, "%08lx-%08lx [%08lx]: %s\n",
 290                              entry->sq_addr, entry->sq_addr + entry->size,
 291                              entry->addr, entry->name);
 292
 293         return p - buf;
 294 }
 295
 296 static ssize_t mapping_store(const char *buf, size_t count)
 297 {
 298         unsigned long base = 0, len = 0;
 299
 300         sscanf(buf, "%lx %lx", &base, &len);
 301         if (!base)
 302                 return -EIO;
 303
 304         if (likely(len)) {
 305                 int ret = sq_remap(base, len, "Userspace",
 306                                    pgprot_val(PAGE_SHARED));
 307                 if (ret < 0)
 308                         return ret;
 309         } else
 310                 sq_unmap(base);
 311
 312         return count;
 313 }
 314
 315 static struct sq_sysfs_attr mapping_attr =
 316         __ATTR(mapping, 0644, mapping_show, mapping_store);
 317
 318 static struct attribute *sq_sysfs_attrs[] = {
 319         &mapping_attr.attr,
 320         NULL,
 321 };
 322
 323 static struct sysfs_ops sq_sysfs_ops = {
 324         .show   = sq_sysfs_show,
 325         .store  = sq_sysfs_store,
 326 };
 327
 328 static struct kobj_type ktype_percpu_entry = {
 329         .sysfs_ops      = &sq_sysfs_ops,
 330         .default_attrs  = sq_sysfs_attrs,
 331 };
 332
 333 static int __devinit sq_sysdev_add(struct sys_device *sysdev)
 334 {
 335         unsigned int cpu = sysdev->id;
 336         struct kobject *kobj;
 337
 338         sq_kobject[cpu] = kzalloc(sizeof(struct kobject), GFP_KERNEL);
 339         if (unlikely(!sq_kobject[cpu]))
 340                 return -ENOMEM;
 341
 342         kobj = sq_kobject[cpu];
 343         kobj->parent = &sysdev->kobj;
 344         kobject_set_name(kobj, "%s", "sq");
 345         kobj->ktype = &ktype_percpu_entry;
 346
 347         return kobject_register(kobj);
 348 }
 349
 350 static int __devexit sq_sysdev_remove(struct sys_device *sysdev)
 351 {
 352         unsigned int cpu = sysdev->id;
 353         struct kobject *kobj = sq_kobject[cpu];
 354
 355         kobject_unregister(kobj);
 356         return 0;
 357 }
 358
 359 static struct sysdev_driver sq_sysdev_driver = {
 360         .add            = sq_sysdev_add,
 361         .remove         = __devexit_p(sq_sysdev_remove),
 362 };
 363
 364 static int __init sq_api_init(void)
 365 {
 366         unsigned int nr_pages = 0x04000000 >> PAGE_SHIFT;
 367         unsigned int size = (nr_pages + (BITS_PER_LONG - 1)) / BITS_PER_LONG;
 368         int ret = -ENOMEM;
 369
 370         printk(KERN_NOTICE "sq: Registering store queue API.\n");
 371
 372         sq_cache = kmem_cache_create("store_queue_cache",
 373                                 sizeof(struct sq_mapping), 0, 0,
 374                                 NULL, NULL);
 375         if (unlikely(!sq_cache))
 376                 return ret;
 377
 378         sq_bitmap = kzalloc(size, GFP_KERNEL);
 379         if (unlikely(!sq_bitmap))
 380                 goto out;
 381
 382         ret = sysdev_driver_register(&cpu_sysdev_class, &sq_sysdev_driver);
 383         if (unlikely(ret != 0))
 384                 goto out;
 385
 386         return 0;
 387
 388 out:
 389         kfree(sq_bitmap);
 390         kmem_cache_destroy(sq_cache);
 391
 392         return ret;
 393 }
 394
 395 static void __exit sq_api_exit(void)
 396 {
 397         sysdev_driver_unregister(&cpu_sysdev_class, &sq_sysdev_driver);
 398         kfree(sq_bitmap);
 399         kmem_cache_destroy(sq_cache);
 400 }
 401
 402 module_init(sq_api_init);
 403 module_exit(sq_api_exit);
 404
 405 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, M. R. Brown <mrbrown@0xd6.org>");
 406 MODULE_DESCRIPTION("Simple API for SH-4 integrated Store Queues");
 407 MODULE_LICENSE("GPL");