11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * linux/arch/arm/mm/ioremap.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Re-map IO memory to kernel address space so that we can access it. 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * (C) Copyright 1995 1996 Linus Torvalds 71da177e4SLinus Torvalds * 81da177e4SLinus Torvalds * Hacked for ARM by Phil Blundell <philb@gnu.org> 91da177e4SLinus Torvalds * Hacked to allow all architectures to build, and various cleanups 101da177e4SLinus Torvalds * by Russell King 111da177e4SLinus Torvalds * 121da177e4SLinus Torvalds * This allows a driver to remap an arbitrary region of bus memory into 131da177e4SLinus Torvalds * virtual space. One should *only* use readl, writel, memcpy_toio and 141da177e4SLinus Torvalds * so on with such remapped areas. 151da177e4SLinus Torvalds * 161da177e4SLinus Torvalds * Because the ARM only has a 32-bit address space we can't address the 171da177e4SLinus Torvalds * whole of the (physical) PCI space at once. PCI huge-mode addressing 181da177e4SLinus Torvalds * allows us to circumvent this restriction by splitting PCI space into 191da177e4SLinus Torvalds * two 2GB chunks and mapping only one at a time into processor memory. 201da177e4SLinus Torvalds * We use MMU protection domains to trap any attempt to access the bank 211da177e4SLinus Torvalds * that is not currently mapped. (This isn't fully implemented yet.) 221da177e4SLinus Torvalds */ 231da177e4SLinus Torvalds #include <linux/module.h> 241da177e4SLinus Torvalds #include <linux/errno.h> 251da177e4SLinus Torvalds #include <linux/mm.h> 261da177e4SLinus Torvalds #include <linux/vmalloc.h> 27fced80c7SRussell King #include <linux/io.h> 281da177e4SLinus Torvalds 290ba8b9b2SRussell King #include <asm/cputype.h> 301da177e4SLinus Torvalds #include <asm/cacheflush.h> 31ff0daca5SRussell King #include <asm/mmu_context.h> 32ff0daca5SRussell King #include <asm/pgalloc.h> 331da177e4SLinus Torvalds #include <asm/tlbflush.h> 34ff0daca5SRussell King #include <asm/sizes.h> 35ff0daca5SRussell King 36b29e9f5eSRussell King #include <asm/mach/map.h> 37b29e9f5eSRussell King #include "mm.h" 38b29e9f5eSRussell King 39ff0daca5SRussell King /* 40a069c896SLennert Buytenhek * Used by ioremap() and iounmap() code to mark (super)section-mapped 41a069c896SLennert Buytenhek * I/O regions in vm_struct->flags field. 42ff0daca5SRussell King */ 43ff0daca5SRussell King #define VM_ARM_SECTION_MAPPING 0x80000000 441da177e4SLinus Torvalds 4569d3a84aSHiroshi DOYU int ioremap_page(unsigned long virt, unsigned long phys, 4669d3a84aSHiroshi DOYU const struct mem_type *mtype) 4769d3a84aSHiroshi DOYU { 48d7461963SRussell King return ioremap_page_range(virt, virt + PAGE_SIZE, phys, 49d7461963SRussell King __pgprot(mtype->prot_pte)); 5069d3a84aSHiroshi DOYU } 5169d3a84aSHiroshi DOYU EXPORT_SYMBOL(ioremap_page); 52ff0daca5SRussell King 53ff0daca5SRussell King void __check_kvm_seq(struct mm_struct *mm) 54ff0daca5SRussell King { 55ff0daca5SRussell King unsigned int seq; 56ff0daca5SRussell King 57ff0daca5SRussell King do { 58ff0daca5SRussell King seq = init_mm.context.kvm_seq; 59ff0daca5SRussell King memcpy(pgd_offset(mm, VMALLOC_START), 60ff0daca5SRussell King pgd_offset_k(VMALLOC_START), 61ff0daca5SRussell King sizeof(pgd_t) * (pgd_index(VMALLOC_END) - 62ff0daca5SRussell King pgd_index(VMALLOC_START))); 63ff0daca5SRussell King mm->context.kvm_seq = seq; 64ff0daca5SRussell King } while (seq != init_mm.context.kvm_seq); 65ff0daca5SRussell King } 66ff0daca5SRussell King 67ff0daca5SRussell King #ifndef CONFIG_SMP 68ff0daca5SRussell King /* 69ff0daca5SRussell King * Section support is unsafe on SMP - If you iounmap and ioremap a region, 70ff0daca5SRussell King * the other CPUs will not see this change until their next context switch. 71ff0daca5SRussell King * Meanwhile, (eg) if an interrupt comes in on one of those other CPUs 72ff0daca5SRussell King * which requires the new ioremap'd region to be referenced, the CPU will 73ff0daca5SRussell King * reference the _old_ region. 74ff0daca5SRussell King * 7531aa8fd6SRussell King * Note that get_vm_area_caller() allocates a guard 4K page, so we need to 7631aa8fd6SRussell King * mask the size back to 1MB aligned or we will overflow in the loop below. 77ff0daca5SRussell King */ 78ff0daca5SRussell King static void unmap_area_sections(unsigned long virt, unsigned long size) 79ff0daca5SRussell King { 8024f11ec0SRussell King unsigned long addr = virt, end = virt + (size & ~(SZ_1M - 1)); 81ff0daca5SRussell King pgd_t *pgd; 8203a6b827SCatalin Marinas pud_t *pud; 8303a6b827SCatalin Marinas pmd_t *pmdp; 84ff0daca5SRussell King 85ff0daca5SRussell King flush_cache_vunmap(addr, end); 86ff0daca5SRussell King pgd = pgd_offset_k(addr); 8703a6b827SCatalin Marinas pud = pud_offset(pgd, addr); 8803a6b827SCatalin Marinas pmdp = pmd_offset(pud, addr); 89ff0daca5SRussell King do { 9003a6b827SCatalin Marinas pmd_t pmd = *pmdp; 91ff0daca5SRussell King 92ff0daca5SRussell King if (!pmd_none(pmd)) { 93ff0daca5SRussell King /* 94ff0daca5SRussell King * Clear the PMD from the page table, and 95ff0daca5SRussell King * increment the kvm sequence so others 96ff0daca5SRussell King * notice this change. 97ff0daca5SRussell King * 98ff0daca5SRussell King * Note: this is still racy on SMP machines. 99ff0daca5SRussell King */ 100ff0daca5SRussell King pmd_clear(pmdp); 101ff0daca5SRussell King init_mm.context.kvm_seq++; 102ff0daca5SRussell King 103ff0daca5SRussell King /* 104ff0daca5SRussell King * Free the page table, if there was one. 105ff0daca5SRussell King */ 106ff0daca5SRussell King if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE) 1075e541973SBenjamin Herrenschmidt pte_free_kernel(&init_mm, pmd_page_vaddr(pmd)); 108ff0daca5SRussell King } 109ff0daca5SRussell King 11003a6b827SCatalin Marinas addr += PMD_SIZE; 11103a6b827SCatalin Marinas pmdp += 2; 112ff0daca5SRussell King } while (addr < end); 113ff0daca5SRussell King 114ff0daca5SRussell King /* 115ff0daca5SRussell King * Ensure that the active_mm is up to date - we want to 116ff0daca5SRussell King * catch any use-after-iounmap cases. 117ff0daca5SRussell King */ 118ff0daca5SRussell King if (current->active_mm->context.kvm_seq != init_mm.context.kvm_seq) 119ff0daca5SRussell King __check_kvm_seq(current->active_mm); 120ff0daca5SRussell King 121ff0daca5SRussell King flush_tlb_kernel_range(virt, end); 122ff0daca5SRussell King } 123ff0daca5SRussell King 124ff0daca5SRussell King static int 125ff0daca5SRussell King remap_area_sections(unsigned long virt, unsigned long pfn, 126b29e9f5eSRussell King size_t size, const struct mem_type *type) 127ff0daca5SRussell King { 128b29e9f5eSRussell King unsigned long addr = virt, end = virt + size; 129ff0daca5SRussell King pgd_t *pgd; 13003a6b827SCatalin Marinas pud_t *pud; 13103a6b827SCatalin Marinas pmd_t *pmd; 132ff0daca5SRussell King 133ff0daca5SRussell King /* 134ff0daca5SRussell King * Remove and free any PTE-based mapping, and 135ff0daca5SRussell King * sync the current kernel mapping. 136ff0daca5SRussell King */ 137ff0daca5SRussell King unmap_area_sections(virt, size); 138ff0daca5SRussell King 139ff0daca5SRussell King pgd = pgd_offset_k(addr); 14003a6b827SCatalin Marinas pud = pud_offset(pgd, addr); 14103a6b827SCatalin Marinas pmd = pmd_offset(pud, addr); 142ff0daca5SRussell King do { 143b29e9f5eSRussell King pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); 144ff0daca5SRussell King pfn += SZ_1M >> PAGE_SHIFT; 145b29e9f5eSRussell King pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); 146ff0daca5SRussell King pfn += SZ_1M >> PAGE_SHIFT; 147ff0daca5SRussell King flush_pmd_entry(pmd); 148ff0daca5SRussell King 14903a6b827SCatalin Marinas addr += PMD_SIZE; 15003a6b827SCatalin Marinas pmd += 2; 151ff0daca5SRussell King } while (addr < end); 152ff0daca5SRussell King 153ff0daca5SRussell King return 0; 154ff0daca5SRussell King } 155a069c896SLennert Buytenhek 156a069c896SLennert Buytenhek static int 157a069c896SLennert Buytenhek remap_area_supersections(unsigned long virt, unsigned long pfn, 158b29e9f5eSRussell King size_t size, const struct mem_type *type) 159a069c896SLennert Buytenhek { 160b29e9f5eSRussell King unsigned long addr = virt, end = virt + size; 161a069c896SLennert Buytenhek pgd_t *pgd; 16203a6b827SCatalin Marinas pud_t *pud; 16303a6b827SCatalin Marinas pmd_t *pmd; 164a069c896SLennert Buytenhek 165a069c896SLennert Buytenhek /* 166a069c896SLennert Buytenhek * Remove and free any PTE-based mapping, and 167a069c896SLennert Buytenhek * sync the current kernel mapping. 168a069c896SLennert Buytenhek */ 169a069c896SLennert Buytenhek unmap_area_sections(virt, size); 170a069c896SLennert Buytenhek 171a069c896SLennert Buytenhek pgd = pgd_offset_k(virt); 17203a6b827SCatalin Marinas pud = pud_offset(pgd, addr); 17303a6b827SCatalin Marinas pmd = pmd_offset(pud, addr); 174a069c896SLennert Buytenhek do { 175a069c896SLennert Buytenhek unsigned long super_pmd_val, i; 176a069c896SLennert Buytenhek 177b29e9f5eSRussell King super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect | 178b29e9f5eSRussell King PMD_SECT_SUPER; 179a069c896SLennert Buytenhek super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20; 180a069c896SLennert Buytenhek 181a069c896SLennert Buytenhek for (i = 0; i < 8; i++) { 182a069c896SLennert Buytenhek pmd[0] = __pmd(super_pmd_val); 183a069c896SLennert Buytenhek pmd[1] = __pmd(super_pmd_val); 184a069c896SLennert Buytenhek flush_pmd_entry(pmd); 185a069c896SLennert Buytenhek 18603a6b827SCatalin Marinas addr += PMD_SIZE; 18703a6b827SCatalin Marinas pmd += 2; 188a069c896SLennert Buytenhek } 189a069c896SLennert Buytenhek 190a069c896SLennert Buytenhek pfn += SUPERSECTION_SIZE >> PAGE_SHIFT; 191a069c896SLennert Buytenhek } while (addr < end); 192a069c896SLennert Buytenhek 193a069c896SLennert Buytenhek return 0; 194a069c896SLennert Buytenhek } 195ff0daca5SRussell King #endif 196ff0daca5SRussell King 19731aa8fd6SRussell King void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn, 19831aa8fd6SRussell King unsigned long offset, size_t size, unsigned int mtype, void *caller) 1999d4ae727SDeepak Saxena { 200b29e9f5eSRussell King const struct mem_type *type; 201ff0daca5SRussell King int err; 2029d4ae727SDeepak Saxena unsigned long addr; 2039d4ae727SDeepak Saxena struct vm_struct * area; 204a069c896SLennert Buytenhek 205a069c896SLennert Buytenhek /* 206a069c896SLennert Buytenhek * High mappings must be supersection aligned 207a069c896SLennert Buytenhek */ 208a069c896SLennert Buytenhek if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK)) 209a069c896SLennert Buytenhek return NULL; 2109d4ae727SDeepak Saxena 211309caa9cSRussell King /* 212309caa9cSRussell King * Don't allow RAM to be mapped - this causes problems with ARMv6+ 213309caa9cSRussell King */ 21467cfa23aSRussell King if (WARN_ON(pfn_valid(pfn))) 21567cfa23aSRussell King return NULL; 216309caa9cSRussell King 2173603ab2bSRussell King type = get_mem_type(mtype); 2183603ab2bSRussell King if (!type) 2193603ab2bSRussell King return NULL; 220b29e9f5eSRussell King 2216d78b5f9SRussell King /* 2226d78b5f9SRussell King * Page align the mapping size, taking account of any offset. 2236d78b5f9SRussell King */ 2246d78b5f9SRussell King size = PAGE_ALIGN(offset + size); 225c924aff8SRussell King 22631aa8fd6SRussell King area = get_vm_area_caller(size, VM_IOREMAP, caller); 2279d4ae727SDeepak Saxena if (!area) 2289d4ae727SDeepak Saxena return NULL; 2299d4ae727SDeepak Saxena addr = (unsigned long)area->addr; 230ff0daca5SRussell King 231ff0daca5SRussell King #ifndef CONFIG_SMP 232412489afSCatalin Marinas if (DOMAIN_IO == 0 && 233412489afSCatalin Marinas (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) || 2344a56c1e4SRussell King cpu_is_xsc3()) && pfn >= 0x100000 && 235a069c896SLennert Buytenhek !((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) { 236a069c896SLennert Buytenhek area->flags |= VM_ARM_SECTION_MAPPING; 237b29e9f5eSRussell King err = remap_area_supersections(addr, pfn, size, type); 238a069c896SLennert Buytenhek } else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) { 239ff0daca5SRussell King area->flags |= VM_ARM_SECTION_MAPPING; 240b29e9f5eSRussell King err = remap_area_sections(addr, pfn, size, type); 241ff0daca5SRussell King } else 242ff0daca5SRussell King #endif 243d7461963SRussell King err = ioremap_page_range(addr, addr + size, __pfn_to_phys(pfn), 244d7461963SRussell King __pgprot(type->prot_pte)); 245ff0daca5SRussell King 246ff0daca5SRussell King if (err) { 247478922c2SCatalin Marinas vunmap((void *)addr); 2489d4ae727SDeepak Saxena return NULL; 2499d4ae727SDeepak Saxena } 250ff0daca5SRussell King 251ff0daca5SRussell King flush_cache_vmap(addr, addr + size); 252ff0daca5SRussell King return (void __iomem *) (offset + addr); 2539d4ae727SDeepak Saxena } 2549d4ae727SDeepak Saxena 25531aa8fd6SRussell King void __iomem *__arm_ioremap_caller(unsigned long phys_addr, size_t size, 25631aa8fd6SRussell King unsigned int mtype, void *caller) 2571da177e4SLinus Torvalds { 2589d4ae727SDeepak Saxena unsigned long last_addr; 2599d4ae727SDeepak Saxena unsigned long offset = phys_addr & ~PAGE_MASK; 2609d4ae727SDeepak Saxena unsigned long pfn = __phys_to_pfn(phys_addr); 2611da177e4SLinus Torvalds 2629d4ae727SDeepak Saxena /* 2639d4ae727SDeepak Saxena * Don't allow wraparound or zero size 2649d4ae727SDeepak Saxena */ 2651da177e4SLinus Torvalds last_addr = phys_addr + size - 1; 2661da177e4SLinus Torvalds if (!size || last_addr < phys_addr) 2671da177e4SLinus Torvalds return NULL; 2681da177e4SLinus Torvalds 26931aa8fd6SRussell King return __arm_ioremap_pfn_caller(pfn, offset, size, mtype, 27031aa8fd6SRussell King caller); 27131aa8fd6SRussell King } 27231aa8fd6SRussell King 27331aa8fd6SRussell King /* 27431aa8fd6SRussell King * Remap an arbitrary physical address space into the kernel virtual 27531aa8fd6SRussell King * address space. Needed when the kernel wants to access high addresses 27631aa8fd6SRussell King * directly. 27731aa8fd6SRussell King * 27831aa8fd6SRussell King * NOTE! We need to allow non-page-aligned mappings too: we will obviously 27931aa8fd6SRussell King * have to convert them into an offset in a page-aligned mapping, but the 28031aa8fd6SRussell King * caller shouldn't need to know that small detail. 28131aa8fd6SRussell King */ 28231aa8fd6SRussell King void __iomem * 28331aa8fd6SRussell King __arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size, 28431aa8fd6SRussell King unsigned int mtype) 28531aa8fd6SRussell King { 28631aa8fd6SRussell King return __arm_ioremap_pfn_caller(pfn, offset, size, mtype, 28731aa8fd6SRussell King __builtin_return_address(0)); 28831aa8fd6SRussell King } 28931aa8fd6SRussell King EXPORT_SYMBOL(__arm_ioremap_pfn); 29031aa8fd6SRussell King 29131aa8fd6SRussell King void __iomem * 29231aa8fd6SRussell King __arm_ioremap(unsigned long phys_addr, size_t size, unsigned int mtype) 29331aa8fd6SRussell King { 29431aa8fd6SRussell King return __arm_ioremap_caller(phys_addr, size, mtype, 29531aa8fd6SRussell King __builtin_return_address(0)); 2961da177e4SLinus Torvalds } 2973603ab2bSRussell King EXPORT_SYMBOL(__arm_ioremap); 2981da177e4SLinus Torvalds 2996c5482d5STony Lindgren /* 3006c5482d5STony Lindgren * Remap an arbitrary physical address space into the kernel virtual 3016c5482d5STony Lindgren * address space as memory. Needed when the kernel wants to execute 3026c5482d5STony Lindgren * code in external memory. This is needed for reprogramming source 3036c5482d5STony Lindgren * clocks that would affect normal memory for example. Please see 3046c5482d5STony Lindgren * CONFIG_GENERIC_ALLOCATOR for allocating external memory. 3056c5482d5STony Lindgren */ 3066c5482d5STony Lindgren void __iomem * 3076c5482d5STony Lindgren __arm_ioremap_exec(unsigned long phys_addr, size_t size, bool cached) 3086c5482d5STony Lindgren { 3096c5482d5STony Lindgren unsigned int mtype; 3106c5482d5STony Lindgren 3116c5482d5STony Lindgren if (cached) 3126c5482d5STony Lindgren mtype = MT_MEMORY; 3136c5482d5STony Lindgren else 3146c5482d5STony Lindgren mtype = MT_MEMORY_NONCACHED; 3156c5482d5STony Lindgren 3166c5482d5STony Lindgren return __arm_ioremap_caller(phys_addr, size, mtype, 3176c5482d5STony Lindgren __builtin_return_address(0)); 3186c5482d5STony Lindgren } 3196c5482d5STony Lindgren 32009d9bae0SRussell King void __iounmap(volatile void __iomem *io_addr) 3211da177e4SLinus Torvalds { 32209d9bae0SRussell King void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr); 323ceaccbd2SCatalin Marinas #ifndef CONFIG_SMP 324ff0daca5SRussell King struct vm_struct **p, *tmp; 325ff0daca5SRussell King 326ff0daca5SRussell King /* 327ff0daca5SRussell King * If this is a section based mapping we need to handle it 3286cbdc8c5SSimon Arlott * specially as the VM subsystem does not know how to handle 329ff0daca5SRussell King * such a beast. We need the lock here b/c we need to clear 330ff0daca5SRussell King * all the mappings before the area can be reclaimed 331ff0daca5SRussell King * by someone else. 332ff0daca5SRussell King */ 333ff0daca5SRussell King write_lock(&vmlist_lock); 334ff0daca5SRussell King for (p = &vmlist ; (tmp = *p) ; p = &tmp->next) { 335ff0daca5SRussell King if ((tmp->flags & VM_IOREMAP) && (tmp->addr == addr)) { 336ff0daca5SRussell King if (tmp->flags & VM_ARM_SECTION_MAPPING) { 337ff0daca5SRussell King unmap_area_sections((unsigned long)tmp->addr, 338ff0daca5SRussell King tmp->size); 339ff0daca5SRussell King } 340ff0daca5SRussell King break; 341ff0daca5SRussell King } 342ff0daca5SRussell King } 343ff0daca5SRussell King write_unlock(&vmlist_lock); 3447cddc397SLennert Buytenhek #endif 345ff0daca5SRussell King 34609d9bae0SRussell King vunmap(addr); 3471da177e4SLinus Torvalds } 3481da177e4SLinus Torvalds EXPORT_SYMBOL(__iounmap); 349