2 * linux/arch/arm/mm/ioremap.c
4 * Re-map IO memory to kernel address space so that we can access it.
6 * (C) Copyright 1995 1996 Linus Torvalds
8 * Hacked for ARM by Phil Blundell <philb@gnu.org>
9 * Hacked to allow all architectures to build, and various cleanups
12 * This allows a driver to remap an arbitrary region of bus memory into
13 * virtual space. One should *only* use readl, writel, memcpy_toio and
14 * so on with such remapped areas.
16 * Because the ARM only has a 32-bit address space we can't address the
17 * whole of the (physical) PCI space at once. PCI huge-mode addressing
18 * allows us to circumvent this restriction by splitting PCI space into
19 * two 2GB chunks and mapping only one at a time into processor memory.
20 * We use MMU protection domains to trap any attempt to access the bank
21 * that is not currently mapped. (This isn't fully implemented yet.)
23 #include <linux/module.h>
24 #include <linux/errno.h>
26 #include <linux/vmalloc.h>
28 #include <linux/sizes.h>
31 #include <asm/cputype.h>
32 #include <asm/cacheflush.h>
33 #include <asm/mmu_context.h>
34 #include <asm/pgalloc.h>
35 #include <asm/tlbflush.h>
36 #include <asm/system_info.h>
38 #include <asm/mach/map.h>
39 #include <asm/mach/pci.h>
42 int ioremap_page(unsigned long virt, unsigned long phys,
43 const struct mem_type *mtype)
45 return ioremap_page_range(virt, virt + PAGE_SIZE, phys,
46 __pgprot(mtype->prot_pte));
48 EXPORT_SYMBOL(ioremap_page);
50 void __check_vmalloc_seq(struct mm_struct *mm)
55 seq = init_mm.context.vmalloc_seq;
56 memcpy(pgd_offset(mm, VMALLOC_START),
57 pgd_offset_k(VMALLOC_START),
58 sizeof(pgd_t) * (pgd_index(VMALLOC_END) -
59 pgd_index(VMALLOC_START)));
60 mm->context.vmalloc_seq = seq;
61 } while (seq != init_mm.context.vmalloc_seq);
64 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
66 * Section support is unsafe on SMP - If you iounmap and ioremap a region,
67 * the other CPUs will not see this change until their next context switch.
68 * Meanwhile, (eg) if an interrupt comes in on one of those other CPUs
69 * which requires the new ioremap'd region to be referenced, the CPU will
70 * reference the _old_ region.
72 * Note that get_vm_area_caller() allocates a guard 4K page, so we need to
73 * mask the size back to 1MB aligned or we will overflow in the loop below.
75 static void unmap_area_sections(unsigned long virt, unsigned long size)
77 unsigned long addr = virt, end = virt + (size & ~(SZ_1M - 1));
82 flush_cache_vunmap(addr, end);
83 pgd = pgd_offset_k(addr);
84 pud = pud_offset(pgd, addr);
85 pmdp = pmd_offset(pud, addr);
91 * Clear the PMD from the page table, and
92 * increment the vmalloc sequence so others
95 * Note: this is still racy on SMP machines.
98 init_mm.context.vmalloc_seq++;
101 * Free the page table, if there was one.
103 if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE)
104 pte_free_kernel(&init_mm, pmd_page_vaddr(pmd));
109 } while (addr < end);
112 * Ensure that the active_mm is up to date - we want to
113 * catch any use-after-iounmap cases.
115 if (current->active_mm->context.vmalloc_seq != init_mm.context.vmalloc_seq)
116 __check_vmalloc_seq(current->active_mm);
118 flush_tlb_kernel_range(virt, end);
122 remap_area_sections(unsigned long virt, unsigned long pfn,
123 size_t size, const struct mem_type *type)
125 unsigned long addr = virt, end = virt + size;
131 * Remove and free any PTE-based mapping, and
132 * sync the current kernel mapping.
134 unmap_area_sections(virt, size);
136 pgd = pgd_offset_k(addr);
137 pud = pud_offset(pgd, addr);
138 pmd = pmd_offset(pud, addr);
140 pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
141 pfn += SZ_1M >> PAGE_SHIFT;
142 pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
143 pfn += SZ_1M >> PAGE_SHIFT;
144 flush_pmd_entry(pmd);
148 } while (addr < end);
154 remap_area_supersections(unsigned long virt, unsigned long pfn,
155 size_t size, const struct mem_type *type)
157 unsigned long addr = virt, end = virt + size;
163 * Remove and free any PTE-based mapping, and
164 * sync the current kernel mapping.
166 unmap_area_sections(virt, size);
168 pgd = pgd_offset_k(virt);
169 pud = pud_offset(pgd, addr);
170 pmd = pmd_offset(pud, addr);
172 unsigned long super_pmd_val, i;
174 super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect |
176 super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20;
178 for (i = 0; i < 8; i++) {
179 pmd[0] = __pmd(super_pmd_val);
180 pmd[1] = __pmd(super_pmd_val);
181 flush_pmd_entry(pmd);
187 pfn += SUPERSECTION_SIZE >> PAGE_SHIFT;
188 } while (addr < end);
194 void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
195 unsigned long offset, size_t size, unsigned int mtype, void *caller)
197 const struct mem_type *type;
200 struct vm_struct * area;
202 #ifndef CONFIG_ARM_LPAE
204 * High mappings must be supersection aligned
206 if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK))
210 type = get_mem_type(mtype);
215 * Page align the mapping size, taking account of any offset.
217 size = PAGE_ALIGN(offset + size);
220 * Try to reuse one of the static mapping whenever possible.
222 read_lock(&vmlist_lock);
223 for (area = vmlist; area; area = area->next) {
224 if (!size || (sizeof(phys_addr_t) == 4 && pfn >= 0x100000))
226 if (!(area->flags & VM_ARM_STATIC_MAPPING))
228 if ((area->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype))
230 if (__phys_to_pfn(area->phys_addr) > pfn ||
231 __pfn_to_phys(pfn) + size-1 > area->phys_addr + area->size-1)
233 /* we can drop the lock here as we know *area is static */
234 read_unlock(&vmlist_lock);
235 addr = (unsigned long)area->addr;
236 addr += __pfn_to_phys(pfn) - area->phys_addr;
237 return (void __iomem *) (offset + addr);
239 read_unlock(&vmlist_lock);
242 * Don't allow RAM to be mapped - this causes problems with ARMv6+
244 if (WARN_ON(pfn_valid(pfn)))
247 area = get_vm_area_caller(size, VM_IOREMAP, caller);
250 addr = (unsigned long)area->addr;
251 area->phys_addr = __pfn_to_phys(pfn);
253 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
254 if (DOMAIN_IO == 0 &&
255 (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) ||
256 cpu_is_xsc3()) && pfn >= 0x100000 &&
257 !((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) {
258 area->flags |= VM_ARM_SECTION_MAPPING;
259 err = remap_area_supersections(addr, pfn, size, type);
260 } else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
261 area->flags |= VM_ARM_SECTION_MAPPING;
262 err = remap_area_sections(addr, pfn, size, type);
265 err = ioremap_page_range(addr, addr + size, __pfn_to_phys(pfn),
266 __pgprot(type->prot_pte));
269 vunmap((void *)addr);
273 flush_cache_vmap(addr, addr + size);
274 return (void __iomem *) (offset + addr);
277 void __iomem *__arm_ioremap_caller(unsigned long phys_addr, size_t size,
278 unsigned int mtype, void *caller)
280 unsigned long last_addr;
281 unsigned long offset = phys_addr & ~PAGE_MASK;
282 unsigned long pfn = __phys_to_pfn(phys_addr);
285 * Don't allow wraparound or zero size
287 last_addr = phys_addr + size - 1;
288 if (!size || last_addr < phys_addr)
291 return __arm_ioremap_pfn_caller(pfn, offset, size, mtype,
296 * Remap an arbitrary physical address space into the kernel virtual
297 * address space. Needed when the kernel wants to access high addresses
300 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
301 * have to convert them into an offset in a page-aligned mapping, but the
302 * caller shouldn't need to know that small detail.
305 __arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
308 return __arm_ioremap_pfn_caller(pfn, offset, size, mtype,
309 __builtin_return_address(0));
311 EXPORT_SYMBOL(__arm_ioremap_pfn);
313 void __iomem * (*arch_ioremap_caller)(unsigned long, size_t,
314 unsigned int, void *) =
315 __arm_ioremap_caller;
318 __arm_ioremap(unsigned long phys_addr, size_t size, unsigned int mtype)
320 return arch_ioremap_caller(phys_addr, size, mtype,
321 __builtin_return_address(0));
323 EXPORT_SYMBOL(__arm_ioremap);
326 * Remap an arbitrary physical address space into the kernel virtual
327 * address space as memory. Needed when the kernel wants to execute
328 * code in external memory. This is needed for reprogramming source
329 * clocks that would affect normal memory for example. Please see
330 * CONFIG_GENERIC_ALLOCATOR for allocating external memory.
333 __arm_ioremap_exec(unsigned long phys_addr, size_t size, bool cached)
340 mtype = MT_MEMORY_NONCACHED;
342 return __arm_ioremap_caller(phys_addr, size, mtype,
343 __builtin_return_address(0));
346 void __iounmap(volatile void __iomem *io_addr)
348 void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
349 struct vm_struct *vm;
351 read_lock(&vmlist_lock);
352 for (vm = vmlist; vm; vm = vm->next) {
355 if (!(vm->flags & VM_IOREMAP))
357 /* If this is a static mapping we must leave it alone */
358 if ((vm->flags & VM_ARM_STATIC_MAPPING) &&
359 (vm->addr <= addr) && (vm->addr + vm->size > addr)) {
360 read_unlock(&vmlist_lock);
363 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
365 * If this is a section based mapping we need to handle it
366 * specially as the VM subsystem does not know how to handle
369 if ((vm->addr == addr) &&
370 (vm->flags & VM_ARM_SECTION_MAPPING)) {
371 unmap_area_sections((unsigned long)vm->addr, vm->size);
376 read_unlock(&vmlist_lock);
381 void (*arch_iounmap)(volatile void __iomem *) = __iounmap;
383 void __arm_iounmap(volatile void __iomem *io_addr)
385 arch_iounmap(io_addr);
387 EXPORT_SYMBOL(__arm_iounmap);
390 int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr)
392 BUG_ON(offset + SZ_64K > IO_SPACE_LIMIT);
394 return ioremap_page_range(PCI_IO_VIRT_BASE + offset,
395 PCI_IO_VIRT_BASE + offset + SZ_64K,
397 __pgprot(get_mem_type(MT_DEVICE)->prot_pte));
399 EXPORT_SYMBOL_GPL(pci_ioremap_io);