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