Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
/*
 *  linux/arch/arm/mm/ioremap.c
 *
 * Re-map IO memory to kernel address space so that we can access it.
 *
 * (C) Copyright 1995 1996 Linus Torvalds
 *
 * Hacked for ARM by Phil Blundell <philb@gnu.org>
 * Hacked to allow all architectures to build, and various cleanups
 * by Russell King
 *
 * This allows a driver to remap an arbitrary region of bus memory into
 * virtual space.  One should *only* use readl, writel, memcpy_toio and
 * so on with such remapped areas.
 *
 * Because the ARM only has a 32-bit address space we can't address the
 * whole of the (physical) PCI space at once.  PCI huge-mode addressing
 * allows us to circumvent this restriction by splitting PCI space into
 * two 2GB chunks and mapping only one at a time into processor memory.
 * We use MMU protection domains to trap any attempt to access the bank
 * that is not currently mapped.  (This isn't fully implemented yet.)
 */
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/io.h>
#include <linux/sizes.h>

#include <asm/cp15.h>
#include <asm/cputype.h>
#include <asm/cacheflush.h>
#include <asm/early_ioremap.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/system_info.h>

#include <asm/mach/map.h>
#include <asm/mach/pci.h>
#include "mm.h"


LIST_HEAD(static_vmlist);

static struct static_vm *find_static_vm_paddr(phys_addr_t paddr,
			size_t size, unsigned int mtype)
{
	struct static_vm *svm;
	struct vm_struct *vm;

	list_for_each_entry(svm, &static_vmlist, list) {
		vm = &svm->vm;
		if (!(vm->flags & VM_ARM_STATIC_MAPPING))
			continue;
		if ((vm->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype))
			continue;

		if (vm->phys_addr > paddr ||
			paddr + size - 1 > vm->phys_addr + vm->size - 1)
			continue;

		return svm;
	}

	return NULL;
}

struct static_vm *find_static_vm_vaddr(void *vaddr)
{
	struct static_vm *svm;
	struct vm_struct *vm;

	list_for_each_entry(svm, &static_vmlist, list) {
		vm = &svm->vm;

		/* static_vmlist is ascending order */
		if (vm->addr > vaddr)
			break;

		if (vm->addr <= vaddr && vm->addr + vm->size > vaddr)
			return svm;
	}

	return NULL;
}

void __init add_static_vm_early(struct static_vm *svm)
{
	struct static_vm *curr_svm;
	struct vm_struct *vm;
	void *vaddr;

	vm = &svm->vm;
	vm_area_add_early(vm);
	vaddr = vm->addr;

	list_for_each_entry(curr_svm, &static_vmlist, list) {
		vm = &curr_svm->vm;

		if (vm->addr > vaddr)
			break;
	}
	list_add_tail(&svm->list, &curr_svm->list);
}

int ioremap_page(unsigned long virt, unsigned long phys,
		 const struct mem_type *mtype)
{
	return ioremap_page_range(virt, virt + PAGE_SIZE, phys,
				  __pgprot(mtype->prot_pte));
}
EXPORT_SYMBOL(ioremap_page);

void __check_vmalloc_seq(struct mm_struct *mm)
{
	unsigned int seq;

	do {
		seq = init_mm.context.vmalloc_seq;
		memcpy(pgd_offset(mm, VMALLOC_START),
		       pgd_offset_k(VMALLOC_START),
		       sizeof(pgd_t) * (pgd_index(VMALLOC_END) -
					pgd_index(VMALLOC_START)));
		mm->context.vmalloc_seq = seq;
	} while (seq != init_mm.context.vmalloc_seq);
}

#if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
/*
 * Section support is unsafe on SMP - If you iounmap and ioremap a region,
 * the other CPUs will not see this change until their next context switch.
 * Meanwhile, (eg) if an interrupt comes in on one of those other CPUs
 * which requires the new ioremap'd region to be referenced, the CPU will
 * reference the _old_ region.
 *
 * Note that get_vm_area_caller() allocates a guard 4K page, so we need to
 * mask the size back to 1MB aligned or we will overflow in the loop below.
 */
static void unmap_area_sections(unsigned long virt, unsigned long size)
{
	unsigned long addr = virt, end = virt + (size & ~(SZ_1M - 1));
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmdp;

	flush_cache_vunmap(addr, end);
	pgd = pgd_offset_k(addr);
	pud = pud_offset(pgd, addr);
	pmdp = pmd_offset(pud, addr);
	do {
		pmd_t pmd = *pmdp;

		if (!pmd_none(pmd)) {
			/*
			 * Clear the PMD from the page table, and
			 * increment the vmalloc sequence so others
			 * notice this change.
			 *
			 * Note: this is still racy on SMP machines.
			 */
			pmd_clear(pmdp);
			init_mm.context.vmalloc_seq++;

			/*
			 * Free the page table, if there was one.
			 */
			if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE)
				pte_free_kernel(&init_mm, pmd_page_vaddr(pmd));
		}

		addr += PMD_SIZE;
		pmdp += 2;
	} while (addr < end);

	/*
	 * Ensure that the active_mm is up to date - we want to
	 * catch any use-after-iounmap cases.
	 */
	if (current->active_mm->context.vmalloc_seq != init_mm.context.vmalloc_seq)
		__check_vmalloc_seq(current->active_mm);

	flush_tlb_kernel_range(virt, end);
}

static int
remap_area_sections(unsigned long virt, unsigned long pfn,
		    size_t size, const struct mem_type *type)
{
	unsigned long addr = virt, end = virt + size;
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;

	/*
	 * Remove and free any PTE-based mapping, and
	 * sync the current kernel mapping.
	 */
	unmap_area_sections(virt, size);

	pgd = pgd_offset_k(addr);
	pud = pud_offset(pgd, addr);
	pmd = pmd_offset(pud, addr);
	do {
		pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
		pfn += SZ_1M >> PAGE_SHIFT;
		pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
		pfn += SZ_1M >> PAGE_SHIFT;
		flush_pmd_entry(pmd);

		addr += PMD_SIZE;
		pmd += 2;
	} while (addr < end);

	return 0;
}

static int
remap_area_supersections(unsigned long virt, unsigned long pfn,
			 size_t size, const struct mem_type *type)
{
	unsigned long addr = virt, end = virt + size;
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;

	/*
	 * Remove and free any PTE-based mapping, and
	 * sync the current kernel mapping.
	 */
	unmap_area_sections(virt, size);

	pgd = pgd_offset_k(virt);
	pud = pud_offset(pgd, addr);
	pmd = pmd_offset(pud, addr);
	do {
		unsigned long super_pmd_val, i;

		super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect |
				PMD_SECT_SUPER;
		super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20;

		for (i = 0; i < 8; i++) {
			pmd[0] = __pmd(super_pmd_val);
			pmd[1] = __pmd(super_pmd_val);
			flush_pmd_entry(pmd);

			addr += PMD_SIZE;
			pmd += 2;
		}

		pfn += SUPERSECTION_SIZE >> PAGE_SHIFT;
	} while (addr < end);

	return 0;
}
#endif

static void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
	unsigned long offset, size_t size, unsigned int mtype, void *caller)
{
	const struct mem_type *type;
	int err;
	unsigned long addr;
	struct vm_struct *area;
	phys_addr_t paddr = __pfn_to_phys(pfn);

#ifndef CONFIG_ARM_LPAE
	/*
	 * High mappings must be supersection aligned
	 */
	if (pfn >= 0x100000 && (paddr & ~SUPERSECTION_MASK))
		return NULL;
#endif

	type = get_mem_type(mtype);
	if (!type)
		return NULL;

	/*
	 * Page align the mapping size, taking account of any offset.
	 */
	size = PAGE_ALIGN(offset + size);

	/*
	 * Try to reuse one of the static mapping whenever possible.
	 */
	if (size && !(sizeof(phys_addr_t) == 4 && pfn >= 0x100000)) {
		struct static_vm *svm;

		svm = find_static_vm_paddr(paddr, size, mtype);
		if (svm) {
			addr = (unsigned long)svm->vm.addr;
			addr += paddr - svm->vm.phys_addr;
			return (void __iomem *) (offset + addr);
		}
	}

	/*
	 * Don't allow RAM to be mapped with mismatched attributes - this
	 * causes problems with ARMv6+
	 */
	if (WARN_ON(pfn_valid(pfn) && mtype != MT_MEMORY_RW))
		return NULL;

	area = get_vm_area_caller(size, VM_IOREMAP, caller);
 	if (!area)
 		return NULL;
 	addr = (unsigned long)area->addr;
	area->phys_addr = paddr;

#if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
	if (DOMAIN_IO == 0 &&
	    (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) ||
	       cpu_is_xsc3()) && pfn >= 0x100000 &&
	       !((paddr | size | addr) & ~SUPERSECTION_MASK)) {
		area->flags |= VM_ARM_SECTION_MAPPING;
		err = remap_area_supersections(addr, pfn, size, type);
	} else if (!((paddr | size | addr) & ~PMD_MASK)) {
		area->flags |= VM_ARM_SECTION_MAPPING;
		err = remap_area_sections(addr, pfn, size, type);
	} else
#endif
		err = ioremap_page_range(addr, addr + size, paddr,
					 __pgprot(type->prot_pte));

	if (err) {
 		vunmap((void *)addr);
 		return NULL;
 	}

	flush_cache_vmap(addr, addr + size);
	return (void __iomem *) (offset + addr);
}

void __iomem *__arm_ioremap_caller(phys_addr_t phys_addr, size_t size,
	unsigned int mtype, void *caller)
{
	phys_addr_t last_addr;
 	unsigned long offset = phys_addr & ~PAGE_MASK;
 	unsigned long pfn = __phys_to_pfn(phys_addr);

 	/*
 	 * Don't allow wraparound or zero size
	 */
	last_addr = phys_addr + size - 1;
	if (!size || last_addr < phys_addr)
		return NULL;

	return __arm_ioremap_pfn_caller(pfn, offset, size, mtype,
			caller);
}

/*
 * Remap an arbitrary physical address space into the kernel virtual
 * address space. Needed when the kernel wants to access high addresses
 * directly.
 *
 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
 * have to convert them into an offset in a page-aligned mapping, but the
 * caller shouldn't need to know that small detail.
 */
void __iomem *
__arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
		  unsigned int mtype)
{
	return __arm_ioremap_pfn_caller(pfn, offset, size, mtype,
					__builtin_return_address(0));
}
EXPORT_SYMBOL(__arm_ioremap_pfn);

void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t,
				      unsigned int, void *) =
	__arm_ioremap_caller;

void __iomem *ioremap(resource_size_t res_cookie, size_t size)
{
	return arch_ioremap_caller(res_cookie, size, MT_DEVICE,
				   __builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap);

void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size)
	__alias(ioremap_cached);

void __iomem *ioremap_cached(resource_size_t res_cookie, size_t size)
{
	return arch_ioremap_caller(res_cookie, size, MT_DEVICE_CACHED,
				   __builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap_cache);
EXPORT_SYMBOL(ioremap_cached);

void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size)
{
	return arch_ioremap_caller(res_cookie, size, MT_DEVICE_WC,
				   __builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap_wc);

/*
 * Remap an arbitrary physical address space into the kernel virtual
 * address space as memory. Needed when the kernel wants to execute
 * code in external memory. This is needed for reprogramming source
 * clocks that would affect normal memory for example. Please see
 * CONFIG_GENERIC_ALLOCATOR for allocating external memory.
 */
void __iomem *
__arm_ioremap_exec(phys_addr_t phys_addr, size_t size, bool cached)
{
	unsigned int mtype;

	if (cached)
		mtype = MT_MEMORY_RWX;
	else
		mtype = MT_MEMORY_RWX_NONCACHED;

	return __arm_ioremap_caller(phys_addr, size, mtype,
			__builtin_return_address(0));
}

void *arch_memremap_wb(phys_addr_t phys_addr, size_t size)
{
	return (__force void *)arch_ioremap_caller(phys_addr, size,
						   MT_MEMORY_RW,
						   __builtin_return_address(0));
}

void __iounmap(volatile void __iomem *io_addr)
{
	void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
	struct static_vm *svm;

	/* If this is a static mapping, we must leave it alone */
	svm = find_static_vm_vaddr(addr);
	if (svm)
		return;

#if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
	{
		struct vm_struct *vm;

		vm = find_vm_area(addr);

		/*
		 * If this is a section based mapping we need to handle it
		 * specially as the VM subsystem does not know how to handle
		 * such a beast.
		 */
		if (vm && (vm->flags & VM_ARM_SECTION_MAPPING))
			unmap_area_sections((unsigned long)vm->addr, vm->size);
	}
#endif

	vunmap(addr);
}

void (*arch_iounmap)(volatile void __iomem *) = __iounmap;

void iounmap(volatile void __iomem *cookie)
{
	arch_iounmap(cookie);
}
EXPORT_SYMBOL(iounmap);

#ifdef CONFIG_PCI
static int pci_ioremap_mem_type = MT_DEVICE;

void pci_ioremap_set_mem_type(int mem_type)
{
	pci_ioremap_mem_type = mem_type;
}

int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr)
{
	BUG_ON(offset + SZ_64K - 1 > IO_SPACE_LIMIT);

	return ioremap_page_range(PCI_IO_VIRT_BASE + offset,
				  PCI_IO_VIRT_BASE + offset + SZ_64K,
				  phys_addr,
				  __pgprot(get_mem_type(pci_ioremap_mem_type)->prot_pte));
}
EXPORT_SYMBOL_GPL(pci_ioremap_io);

void __iomem *pci_remap_cfgspace(resource_size_t res_cookie, size_t size)
{
	return arch_ioremap_caller(res_cookie, size, MT_UNCACHED,
				   __builtin_return_address(0));
}
EXPORT_SYMBOL_GPL(pci_remap_cfgspace);
#endif

/*
 * Must be called after early_fixmap_init
 */
void __init early_ioremap_init(void)
{
	early_ioremap_setup();
}