1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * linux/arch/arm/mm/ioremap.c |
4 | * |
5 | * Re-map IO memory to kernel address space so that we can access it. |
6 | * |
7 | * (C) Copyright 1995 1996 Linus Torvalds |
8 | * |
9 | * Hacked for ARM by Phil Blundell <philb@gnu.org> |
10 | * Hacked to allow all architectures to build, and various cleanups |
11 | * by Russell King |
12 | * |
13 | * This allows a driver to remap an arbitrary region of bus memory into |
14 | * virtual space. One should *only* use readl, writel, memcpy_toio and |
15 | * so on with such remapped areas. |
16 | * |
17 | * Because the ARM only has a 32-bit address space we can't address the |
18 | * whole of the (physical) PCI space at once. PCI huge-mode addressing |
19 | * allows us to circumvent this restriction by splitting PCI space into |
20 | * two 2GB chunks and mapping only one at a time into processor memory. |
21 | * We use MMU protection domains to trap any attempt to access the bank |
22 | * that is not currently mapped. (This isn't fully implemented yet.) |
23 | */ |
24 | #include <linux/module.h> |
25 | #include <linux/errno.h> |
26 | #include <linux/mm.h> |
27 | #include <linux/vmalloc.h> |
28 | #include <linux/io.h> |
29 | #include <linux/sizes.h> |
30 | #include <linux/memblock.h> |
31 | |
32 | #include <asm/cp15.h> |
33 | #include <asm/cputype.h> |
34 | #include <asm/cacheflush.h> |
35 | #include <asm/early_ioremap.h> |
36 | #include <asm/mmu_context.h> |
37 | #include <asm/pgalloc.h> |
38 | #include <asm/tlbflush.h> |
39 | #include <asm/set_memory.h> |
40 | #include <asm/system_info.h> |
41 | |
42 | #include <asm/mach/map.h> |
43 | #include <asm/mach/pci.h> |
44 | #include "mm.h" |
45 | |
46 | |
47 | LIST_HEAD(static_vmlist); |
48 | |
49 | static struct static_vm *find_static_vm_paddr(phys_addr_t paddr, |
50 | size_t size, unsigned int mtype) |
51 | { |
52 | struct static_vm *svm; |
53 | struct vm_struct *vm; |
54 | |
55 | list_for_each_entry(svm, &static_vmlist, list) { |
56 | vm = &svm->vm; |
57 | if (!(vm->flags & VM_ARM_STATIC_MAPPING)) |
58 | continue; |
59 | if ((vm->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype)) |
60 | continue; |
61 | |
62 | if (vm->phys_addr > paddr || |
63 | paddr + size - 1 > vm->phys_addr + vm->size - 1) |
64 | continue; |
65 | |
66 | return svm; |
67 | } |
68 | |
69 | return NULL; |
70 | } |
71 | |
72 | struct static_vm *find_static_vm_vaddr(void *vaddr) |
73 | { |
74 | struct static_vm *svm; |
75 | struct vm_struct *vm; |
76 | |
77 | list_for_each_entry(svm, &static_vmlist, list) { |
78 | vm = &svm->vm; |
79 | |
80 | /* static_vmlist is ascending order */ |
81 | if (vm->addr > vaddr) |
82 | break; |
83 | |
84 | if (vm->addr <= vaddr && vm->addr + vm->size > vaddr) |
85 | return svm; |
86 | } |
87 | |
88 | return NULL; |
89 | } |
90 | |
91 | void __init add_static_vm_early(struct static_vm *svm) |
92 | { |
93 | struct static_vm *curr_svm; |
94 | struct vm_struct *vm; |
95 | void *vaddr; |
96 | |
97 | vm = &svm->vm; |
98 | vm_area_add_early(vm); |
99 | vaddr = vm->addr; |
100 | |
101 | list_for_each_entry(curr_svm, &static_vmlist, list) { |
102 | vm = &curr_svm->vm; |
103 | |
104 | if (vm->addr > vaddr) |
105 | break; |
106 | } |
107 | list_add_tail(new: &svm->list, head: &curr_svm->list); |
108 | } |
109 | |
110 | int ioremap_page(unsigned long virt, unsigned long phys, |
111 | const struct mem_type *mtype) |
112 | { |
113 | return vmap_page_range(addr: virt, end: virt + PAGE_SIZE, phys_addr: phys, |
114 | __pgprot(mtype->prot_pte)); |
115 | } |
116 | EXPORT_SYMBOL(ioremap_page); |
117 | |
118 | void __check_vmalloc_seq(struct mm_struct *mm) |
119 | { |
120 | int seq; |
121 | |
122 | do { |
123 | seq = atomic_read(v: &init_mm.context.vmalloc_seq); |
124 | memcpy(pgd_offset(mm, VMALLOC_START), |
125 | pgd_offset_k(VMALLOC_START), |
126 | sizeof(pgd_t) * (pgd_index(VMALLOC_END) - |
127 | pgd_index(VMALLOC_START))); |
128 | /* |
129 | * Use a store-release so that other CPUs that observe the |
130 | * counter's new value are guaranteed to see the results of the |
131 | * memcpy as well. |
132 | */ |
133 | atomic_set_release(v: &mm->context.vmalloc_seq, i: seq); |
134 | } while (seq != atomic_read(v: &init_mm.context.vmalloc_seq)); |
135 | } |
136 | |
137 | #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) |
138 | /* |
139 | * Section support is unsafe on SMP - If you iounmap and ioremap a region, |
140 | * the other CPUs will not see this change until their next context switch. |
141 | * Meanwhile, (eg) if an interrupt comes in on one of those other CPUs |
142 | * which requires the new ioremap'd region to be referenced, the CPU will |
143 | * reference the _old_ region. |
144 | * |
145 | * Note that get_vm_area_caller() allocates a guard 4K page, so we need to |
146 | * mask the size back to 1MB aligned or we will overflow in the loop below. |
147 | */ |
148 | static void unmap_area_sections(unsigned long virt, unsigned long size) |
149 | { |
150 | unsigned long addr = virt, end = virt + (size & ~(SZ_1M - 1)); |
151 | pmd_t *pmdp = pmd_off_k(addr); |
152 | |
153 | do { |
154 | pmd_t pmd = *pmdp; |
155 | |
156 | if (!pmd_none(pmd)) { |
157 | /* |
158 | * Clear the PMD from the page table, and |
159 | * increment the vmalloc sequence so others |
160 | * notice this change. |
161 | * |
162 | * Note: this is still racy on SMP machines. |
163 | */ |
164 | pmd_clear(pmdp); |
165 | atomic_inc_return_release(&init_mm.context.vmalloc_seq); |
166 | |
167 | /* |
168 | * Free the page table, if there was one. |
169 | */ |
170 | if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE) |
171 | pte_free_kernel(&init_mm, pmd_page_vaddr(pmd)); |
172 | } |
173 | |
174 | addr += PMD_SIZE; |
175 | pmdp += 2; |
176 | } while (addr < end); |
177 | |
178 | /* |
179 | * Ensure that the active_mm is up to date - we want to |
180 | * catch any use-after-iounmap cases. |
181 | */ |
182 | check_vmalloc_seq(current->active_mm); |
183 | |
184 | flush_tlb_kernel_range(virt, end); |
185 | } |
186 | |
187 | static int |
188 | remap_area_sections(unsigned long virt, unsigned long pfn, |
189 | size_t size, const struct mem_type *type) |
190 | { |
191 | unsigned long addr = virt, end = virt + size; |
192 | pmd_t *pmd = pmd_off_k(addr); |
193 | |
194 | /* |
195 | * Remove and free any PTE-based mapping, and |
196 | * sync the current kernel mapping. |
197 | */ |
198 | unmap_area_sections(virt, size); |
199 | |
200 | do { |
201 | pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); |
202 | pfn += SZ_1M >> PAGE_SHIFT; |
203 | pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); |
204 | pfn += SZ_1M >> PAGE_SHIFT; |
205 | flush_pmd_entry(pmd); |
206 | |
207 | addr += PMD_SIZE; |
208 | pmd += 2; |
209 | } while (addr < end); |
210 | |
211 | return 0; |
212 | } |
213 | |
214 | static int |
215 | remap_area_supersections(unsigned long virt, unsigned long pfn, |
216 | size_t size, const struct mem_type *type) |
217 | { |
218 | unsigned long addr = virt, end = virt + size; |
219 | pmd_t *pmd = pmd_off_k(addr); |
220 | |
221 | /* |
222 | * Remove and free any PTE-based mapping, and |
223 | * sync the current kernel mapping. |
224 | */ |
225 | unmap_area_sections(virt, size); |
226 | do { |
227 | unsigned long super_pmd_val, i; |
228 | |
229 | super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect | |
230 | PMD_SECT_SUPER; |
231 | super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20; |
232 | |
233 | for (i = 0; i < 8; i++) { |
234 | pmd[0] = __pmd(super_pmd_val); |
235 | pmd[1] = __pmd(super_pmd_val); |
236 | flush_pmd_entry(pmd); |
237 | |
238 | addr += PMD_SIZE; |
239 | pmd += 2; |
240 | } |
241 | |
242 | pfn += SUPERSECTION_SIZE >> PAGE_SHIFT; |
243 | } while (addr < end); |
244 | |
245 | return 0; |
246 | } |
247 | #endif |
248 | |
249 | static void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn, |
250 | unsigned long offset, size_t size, unsigned int mtype, void *caller) |
251 | { |
252 | const struct mem_type *type; |
253 | int err; |
254 | unsigned long addr; |
255 | struct vm_struct *area; |
256 | phys_addr_t paddr = __pfn_to_phys(pfn); |
257 | |
258 | #ifndef CONFIG_ARM_LPAE |
259 | /* |
260 | * High mappings must be supersection aligned |
261 | */ |
262 | if (pfn >= 0x100000 && (paddr & ~SUPERSECTION_MASK)) |
263 | return NULL; |
264 | #endif |
265 | |
266 | type = get_mem_type(type: mtype); |
267 | if (!type) |
268 | return NULL; |
269 | |
270 | /* |
271 | * Page align the mapping size, taking account of any offset. |
272 | */ |
273 | size = PAGE_ALIGN(offset + size); |
274 | |
275 | /* |
276 | * Try to reuse one of the static mapping whenever possible. |
277 | */ |
278 | if (size && !(sizeof(phys_addr_t) == 4 && pfn >= 0x100000)) { |
279 | struct static_vm *svm; |
280 | |
281 | svm = find_static_vm_paddr(paddr, size, mtype); |
282 | if (svm) { |
283 | addr = (unsigned long)svm->vm.addr; |
284 | addr += paddr - svm->vm.phys_addr; |
285 | return (void __iomem *) (offset + addr); |
286 | } |
287 | } |
288 | |
289 | /* |
290 | * Don't allow RAM to be mapped with mismatched attributes - this |
291 | * causes problems with ARMv6+ |
292 | */ |
293 | if (WARN_ON(memblock_is_map_memory(PFN_PHYS(pfn)) && |
294 | mtype != MT_MEMORY_RW)) |
295 | return NULL; |
296 | |
297 | area = get_vm_area_caller(size, VM_IOREMAP, caller); |
298 | if (!area) |
299 | return NULL; |
300 | addr = (unsigned long)area->addr; |
301 | area->phys_addr = paddr; |
302 | |
303 | #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) |
304 | if (DOMAIN_IO == 0 && |
305 | (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) || |
306 | cpu_is_xsc3()) && pfn >= 0x100000 && |
307 | !((paddr | size | addr) & ~SUPERSECTION_MASK)) { |
308 | area->flags |= VM_ARM_SECTION_MAPPING; |
309 | err = remap_area_supersections(addr, pfn, size, type); |
310 | } else if (!((paddr | size | addr) & ~PMD_MASK)) { |
311 | area->flags |= VM_ARM_SECTION_MAPPING; |
312 | err = remap_area_sections(addr, pfn, size, type); |
313 | } else |
314 | #endif |
315 | err = ioremap_page_range(addr, end: addr + size, phys_addr: paddr, |
316 | __pgprot(type->prot_pte)); |
317 | |
318 | if (err) { |
319 | vunmap(addr: (void *)addr); |
320 | return NULL; |
321 | } |
322 | |
323 | flush_cache_vmap(start: addr, end: addr + size); |
324 | return (void __iomem *) (offset + addr); |
325 | } |
326 | |
327 | void __iomem *__arm_ioremap_caller(phys_addr_t phys_addr, size_t size, |
328 | unsigned int mtype, void *caller) |
329 | { |
330 | phys_addr_t last_addr; |
331 | unsigned long offset = phys_addr & ~PAGE_MASK; |
332 | unsigned long pfn = __phys_to_pfn(phys_addr); |
333 | |
334 | /* |
335 | * Don't allow wraparound or zero size |
336 | */ |
337 | last_addr = phys_addr + size - 1; |
338 | if (!size || last_addr < phys_addr) |
339 | return NULL; |
340 | |
341 | return __arm_ioremap_pfn_caller(pfn, offset, size, mtype, |
342 | caller); |
343 | } |
344 | |
345 | /* |
346 | * Remap an arbitrary physical address space into the kernel virtual |
347 | * address space. Needed when the kernel wants to access high addresses |
348 | * directly. |
349 | * |
350 | * NOTE! We need to allow non-page-aligned mappings too: we will obviously |
351 | * have to convert them into an offset in a page-aligned mapping, but the |
352 | * caller shouldn't need to know that small detail. |
353 | */ |
354 | void __iomem * |
355 | __arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size, |
356 | unsigned int mtype) |
357 | { |
358 | return __arm_ioremap_pfn_caller(pfn, offset, size, mtype, |
359 | caller: __builtin_return_address(0)); |
360 | } |
361 | EXPORT_SYMBOL(__arm_ioremap_pfn); |
362 | |
363 | void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t, |
364 | unsigned int, void *) = |
365 | __arm_ioremap_caller; |
366 | |
367 | void __iomem *ioremap(resource_size_t res_cookie, size_t size) |
368 | { |
369 | return arch_ioremap_caller(res_cookie, size, MT_DEVICE, |
370 | __builtin_return_address(0)); |
371 | } |
372 | EXPORT_SYMBOL(ioremap); |
373 | |
374 | void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size) |
375 | { |
376 | return arch_ioremap_caller(res_cookie, size, MT_DEVICE_CACHED, |
377 | __builtin_return_address(0)); |
378 | } |
379 | EXPORT_SYMBOL(ioremap_cache); |
380 | |
381 | void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size) |
382 | { |
383 | return arch_ioremap_caller(res_cookie, size, MT_DEVICE_WC, |
384 | __builtin_return_address(0)); |
385 | } |
386 | EXPORT_SYMBOL(ioremap_wc); |
387 | |
388 | /* |
389 | * Remap an arbitrary physical address space into the kernel virtual |
390 | * address space as memory. Needed when the kernel wants to execute |
391 | * code in external memory. This is needed for reprogramming source |
392 | * clocks that would affect normal memory for example. Please see |
393 | * CONFIG_GENERIC_ALLOCATOR for allocating external memory. |
394 | */ |
395 | void __iomem * |
396 | __arm_ioremap_exec(phys_addr_t phys_addr, size_t size, bool cached) |
397 | { |
398 | unsigned int mtype; |
399 | |
400 | if (cached) |
401 | mtype = MT_MEMORY_RWX; |
402 | else |
403 | mtype = MT_MEMORY_RWX_NONCACHED; |
404 | |
405 | return __arm_ioremap_caller(phys_addr, size, mtype, |
406 | caller: __builtin_return_address(0)); |
407 | } |
408 | |
409 | void __arm_iomem_set_ro(void __iomem *ptr, size_t size) |
410 | { |
411 | set_memory_ro(addr: (unsigned long)ptr, PAGE_ALIGN(size) / PAGE_SIZE); |
412 | } |
413 | |
414 | void *arch_memremap_wb(phys_addr_t phys_addr, size_t size) |
415 | { |
416 | return (__force void *)arch_ioremap_caller(phys_addr, size, |
417 | MT_MEMORY_RW, |
418 | __builtin_return_address(0)); |
419 | } |
420 | |
421 | void iounmap(volatile void __iomem *io_addr) |
422 | { |
423 | void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr); |
424 | struct static_vm *svm; |
425 | |
426 | /* If this is a static mapping, we must leave it alone */ |
427 | svm = find_static_vm_vaddr(vaddr: addr); |
428 | if (svm) |
429 | return; |
430 | |
431 | #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) |
432 | { |
433 | struct vm_struct *vm; |
434 | |
435 | vm = find_vm_area(addr); |
436 | |
437 | /* |
438 | * If this is a section based mapping we need to handle it |
439 | * specially as the VM subsystem does not know how to handle |
440 | * such a beast. |
441 | */ |
442 | if (vm && (vm->flags & VM_ARM_SECTION_MAPPING)) |
443 | unmap_area_sections((unsigned long)vm->addr, vm->size); |
444 | } |
445 | #endif |
446 | |
447 | vunmap(addr); |
448 | } |
449 | EXPORT_SYMBOL(iounmap); |
450 | |
451 | #if defined(CONFIG_PCI) || IS_ENABLED(CONFIG_PCMCIA) |
452 | static int pci_ioremap_mem_type = MT_DEVICE; |
453 | |
454 | void pci_ioremap_set_mem_type(int mem_type) |
455 | { |
456 | pci_ioremap_mem_type = mem_type; |
457 | } |
458 | |
459 | int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) |
460 | { |
461 | unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start; |
462 | |
463 | if (!(res->flags & IORESOURCE_IO)) |
464 | return -EINVAL; |
465 | |
466 | if (res->end > IO_SPACE_LIMIT) |
467 | return -EINVAL; |
468 | |
469 | return vmap_page_range(addr: vaddr, end: vaddr + resource_size(res), phys_addr, |
470 | __pgprot(get_mem_type(pci_ioremap_mem_type)->prot_pte)); |
471 | } |
472 | EXPORT_SYMBOL(pci_remap_iospace); |
473 | |
474 | void __iomem *pci_remap_cfgspace(resource_size_t res_cookie, size_t size) |
475 | { |
476 | return arch_ioremap_caller(res_cookie, size, MT_UNCACHED, |
477 | __builtin_return_address(0)); |
478 | } |
479 | EXPORT_SYMBOL_GPL(pci_remap_cfgspace); |
480 | #endif |
481 | |
482 | /* |
483 | * Must be called after early_fixmap_init |
484 | */ |
485 | void __init early_ioremap_init(void) |
486 | { |
487 | early_ioremap_setup(); |
488 | } |
489 | |
490 | bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size, |
491 | unsigned long flags) |
492 | { |
493 | unsigned long pfn = PHYS_PFN(offset); |
494 | |
495 | return memblock_is_map_memory(addr: pfn); |
496 | } |
497 | |