1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * arch/sh/kernel/cpu/sh4/sq.c
4 *
5 * General management API for SH-4 integrated Store Queues
6 *
7 * Copyright (C) 2001 - 2006 Paul Mundt
8 * Copyright (C) 2001, 2002 M. R. Brown
9 */
10 #include <linux/init.h>
11 #include <linux/cpu.h>
12 #include <linux/bitmap.h>
13 #include <linux/device.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/vmalloc.h>
18 #include <linux/mm.h>
19 #include <linux/io.h>
20 #include <linux/prefetch.h>
21 #include <asm/page.h>
22 #include <asm/cacheflush.h>
23 #include <cpu/sq.h>
24
25 struct sq_mapping;
26
27 struct sq_mapping {
28 const char *name;
29
30 unsigned long sq_addr;
31 unsigned long addr;
32 unsigned int size;
33
34 struct sq_mapping *next;
35 };
36
37 static struct sq_mapping *sq_mapping_list;
38 static DEFINE_SPINLOCK(sq_mapping_lock);
39 static struct kmem_cache *sq_cache;
40 static unsigned long *sq_bitmap;
41
42 #define store_queue_barrier() \
43 do { \
44 (void)__raw_readl(P4SEG_STORE_QUE); \
45 __raw_writel(0, P4SEG_STORE_QUE + 0); \
46 __raw_writel(0, P4SEG_STORE_QUE + 8); \
47 } while (0);
48
49 /**
50 * sq_flush_range - Flush (prefetch) a specific SQ range
51 * @start: the store queue address to start flushing from
52 * @len: the length to flush
53 *
54 * Flushes the store queue cache from @start to @start + @len in a
55 * linear fashion.
56 */
57 void sq_flush_range(unsigned long start, unsigned int len)
58 {
59 unsigned long *sq = (unsigned long *)start;
60
61 /* Flush the queues */
62 for (len >>= 5; len--; sq += 8)
63 prefetchw(sq);
64
65 /* Wait for completion */
66 store_queue_barrier();
67 }
68 EXPORT_SYMBOL(sq_flush_range);
69
70 static inline void sq_mapping_list_add(struct sq_mapping *map)
71 {
72 struct sq_mapping **p, *tmp;
73
74 spin_lock_irq(&sq_mapping_lock);
75
76 p = &sq_mapping_list;
77 while ((tmp = *p) != NULL)
78 p = &tmp->next;
79
80 map->next = tmp;
81 *p = map;
82
83 spin_unlock_irq(&sq_mapping_lock);
84 }
85
86 static inline void sq_mapping_list_del(struct sq_mapping *map)
87 {
88 struct sq_mapping **p, *tmp;
89
90 spin_lock_irq(&sq_mapping_lock);
91
92 for (p = &sq_mapping_list; (tmp = *p); p = &tmp->next)
93 if (tmp == map) {
94 *p = tmp->next;
95 break;
96 }
97
98 spin_unlock_irq(&sq_mapping_lock);
99 }
100
101 static int __sq_remap(struct sq_mapping *map, pgprot_t prot)
102 {
103 #if defined(CONFIG_MMU)
104 struct vm_struct *vma;
105
106 vma = __get_vm_area_caller(map->size, VM_IOREMAP, map->sq_addr,
107 SQ_ADDRMAX, __builtin_return_address(0));
108 if (!vma)
109 return -ENOMEM;
110
111 vma->phys_addr = map->addr;
112
113 if (ioremap_page_range((unsigned long)vma->addr,
114 (unsigned long)vma->addr + map->size,
115 vma->phys_addr, prot)) {
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 __raw_writel(((map->addr >> 26) << 2) & 0x1c, SQ_QACR0);
126 __raw_writel(((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 * @prot: Protection bits.
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, pgprot_t prot)
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, prot);
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 * @vaddr: 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 int page;
211
212 for (p = &sq_mapping_list; (map = *p); p = &map->next)
213 if (map->sq_addr == vaddr)
214 break;
215
216 if (unlikely(!map)) {
217 printk("%s: bad store queue address 0x%08lx\n",
218 __func__, vaddr);
219 return;
220 }
221
222 page = (map->sq_addr - P4SEG_STORE_QUE) >> PAGE_SHIFT;
223 bitmap_release_region(sq_bitmap, page, get_order(map->size));
224
225 #ifdef CONFIG_MMU
226 {
227 /*
228 * Tear down the VMA in the MMU case.
229 */
230 struct vm_struct *vma;
231
232 vma = remove_vm_area((void *)(map->sq_addr & PAGE_MASK));
233 if (!vma) {
234 printk(KERN_ERR "%s: bad address 0x%08lx\n",
235 __func__, map->sq_addr);
236 return;
237 }
238 }
239 #endif
240
241 sq_mapping_list_del(map);
242
243 kmem_cache_free(sq_cache, map);
244 }
245 EXPORT_SYMBOL(sq_unmap);
246
247 /*
248 * Needlessly complex sysfs interface. Unfortunately it doesn't seem like
249 * there is any other easy way to add things on a per-cpu basis without
250 * putting the directory entries somewhere stupid and having to create
251 * links in sysfs by hand back in to the per-cpu directories.
252 *
253 * Some day we may want to have an additional abstraction per store
254 * queue, but considering the kobject hell we already have to deal with,
255 * it's simply not worth the trouble.
256 */
257 static struct kobject *sq_kobject[NR_CPUS];
258
259 struct sq_sysfs_attr {
260 struct attribute attr;
261 ssize_t (*show)(char *buf);
262 ssize_t (*store)(const char *buf, size_t count);
263 };
264
265 #define to_sq_sysfs_attr(a) container_of(a, struct sq_sysfs_attr, attr)
266
267 static ssize_t sq_sysfs_show(struct kobject *kobj, struct attribute *attr,
268 char *buf)
269 {
270 struct sq_sysfs_attr *sattr = to_sq_sysfs_attr(attr);
271
272 if (likely(sattr->show))
273 return sattr->show(buf);
274
275 return -EIO;
276 }
277
278 static ssize_t sq_sysfs_store(struct kobject *kobj, struct attribute *attr,
279 const char *buf, size_t count)
280 {
281 struct sq_sysfs_attr *sattr = to_sq_sysfs_attr(attr);
282
283 if (likely(sattr->store))
284 return sattr->store(buf, count);
285
286 return -EIO;
287 }
288
289 static ssize_t mapping_show(char *buf)
290 {
291 struct sq_mapping **list, *entry;
292 char *p = buf;
293
294 for (list = &sq_mapping_list; (entry = *list); list = &entry->next)
295 p += sprintf(p, "%08lx-%08lx [%08lx]: %s\n",
296 entry->sq_addr, entry->sq_addr + entry->size,
297 entry->addr, entry->name);
298
299 return p - buf;
300 }
301
302 static ssize_t mapping_store(const char *buf, size_t count)
303 {
304 unsigned long base = 0, len = 0;
305
306 sscanf(buf, "%lx %lx", &base, &len);
307 if (!base)
308 return -EIO;
309
310 if (likely(len)) {
311 int ret = sq_remap(base, len, "Userspace", PAGE_SHARED);
312 if (ret < 0)
313 return ret;
314 } else
315 sq_unmap(base);
316
317 return count;
318 }
319
320 static struct sq_sysfs_attr mapping_attr =
321 __ATTR(mapping, 0644, mapping_show, mapping_store);
322
323 static struct attribute *sq_sysfs_attrs[] = {
324 &mapping_attr.attr,
325 NULL,
326 };
327 ATTRIBUTE_GROUPS(sq_sysfs);
328
329 static const struct sysfs_ops sq_sysfs_ops = {
330 .show = sq_sysfs_show,
331 .store = sq_sysfs_store,
332 };
333
334 static struct kobj_type ktype_percpu_entry = {
335 .sysfs_ops = &sq_sysfs_ops,
336 .default_groups = sq_sysfs_groups,
337 };
338
339 static int sq_dev_add(struct device *dev, struct subsys_interface *sif)
340 {
341 unsigned int cpu = dev->id;
342 struct kobject *kobj;
343 int error;
344
345 sq_kobject[cpu] = kzalloc(sizeof(struct kobject), GFP_KERNEL);
346 if (unlikely(!sq_kobject[cpu]))
347 return -ENOMEM;
348
349 kobj = sq_kobject[cpu];
350 error = kobject_init_and_add(kobj, &ktype_percpu_entry, &dev->kobj,
351 "%s", "sq");
352 if (!error)
353 kobject_uevent(kobj, KOBJ_ADD);
354 return error;
355 }
356
357 static void sq_dev_remove(struct device *dev, struct subsys_interface *sif)
358 {
359 unsigned int cpu = dev->id;
360 struct kobject *kobj = sq_kobject[cpu];
361
362 kobject_put(kobj);
363 }
364
365 static struct subsys_interface sq_interface = {
366 .name = "sq",
367 .subsys = &cpu_subsys,
368 .add_dev = sq_dev_add,
369 .remove_dev = sq_dev_remove,
370 };
371
372 static int __init sq_api_init(void)
373 {
374 unsigned int nr_pages = 0x04000000 >> PAGE_SHIFT;
375 int ret = -ENOMEM;
376
377 printk(KERN_NOTICE "sq: Registering store queue API.\n");
378
379 sq_cache = kmem_cache_create("store_queue_cache",
380 sizeof(struct sq_mapping), 0, 0, NULL);
381 if (unlikely(!sq_cache))
382 return ret;
383
384 sq_bitmap = bitmap_zalloc(nr_pages, GFP_KERNEL);
385 if (unlikely(!sq_bitmap))
386 goto out;
387
388 ret = subsys_interface_register(&sq_interface);
389 if (unlikely(ret != 0))
390 goto out;
391
392 return 0;
393
394 out:
395 bitmap_free(sq_bitmap);
396 kmem_cache_destroy(sq_cache);
397
398 return ret;
399 }
400
401 static void __exit sq_api_exit(void)
402 {
403 subsys_interface_unregister(&sq_interface);
404 bitmap_free(sq_bitmap);
405 kmem_cache_destroy(sq_cache);
406 }
407
408 module_init(sq_api_init);
409 module_exit(sq_api_exit);
410
411 MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, M. R. Brown <mrbrown@0xd6.org>");
412 MODULE_DESCRIPTION("Simple API for SH-4 integrated Store Queues");
413 MODULE_LICENSE("GPL");
414
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