| /* |
| * linux/arch/unicore32/mm/ioremap.c |
| * |
| * Code specific to PKUnity SoC and UniCore ISA |
| * |
| * Copyright (C) 2001-2010 GUAN Xue-tao |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * |
| * Re-map IO memory to kernel address space so that we can access it. |
| * |
| * 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 UniCore 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 <asm/cputype.h> |
| #include <asm/cacheflush.h> |
| #include <asm/mmu_context.h> |
| #include <asm/pgalloc.h> |
| #include <asm/tlbflush.h> |
| #include <asm/sizes.h> |
| |
| #include <mach/map.h> |
| #include "mm.h" |
| |
| /* |
| * Used by ioremap() and iounmap() code to mark (super)section-mapped |
| * I/O regions in vm_struct->flags field. |
| */ |
| #define VM_UNICORE_SECTION_MAPPING 0x80000000 |
| |
| 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); |
| |
| /* |
| * 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 4MB 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_4M - 1)); |
| pgd_t *pgd; |
| |
| flush_cache_vunmap(addr, end); |
| pgd = pgd_offset_k(addr); |
| do { |
| pmd_t pmd, *pmdp = pmd_offset((pud_t *)pgd, addr); |
| |
| pmd = *pmdp; |
| if (!pmd_none(pmd)) { |
| /* |
| * Clear the PMD from the page table, and |
| * increment the kvm sequence so others |
| * notice this change. |
| * |
| * Note: this is still racy on SMP machines. |
| */ |
| pmd_clear(pmdp); |
| |
| /* |
| * 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 += PGDIR_SIZE; |
| pgd++; |
| } while (addr < end); |
| |
| 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; |
| |
| /* |
| * Remove and free any PTE-based mapping, and |
| * sync the current kernel mapping. |
| */ |
| unmap_area_sections(virt, size); |
| |
| pgd = pgd_offset_k(addr); |
| do { |
| pmd_t *pmd = pmd_offset((pud_t *)pgd, addr); |
| |
| set_pmd(pmd, __pmd(__pfn_to_phys(pfn) | type->prot_sect)); |
| pfn += SZ_4M >> PAGE_SHIFT; |
| flush_pmd_entry(pmd); |
| |
| addr += PGDIR_SIZE; |
| pgd++; |
| } while (addr < end); |
| |
| return 0; |
| } |
| |
| void __iomem *__uc32_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; |
| |
| /* |
| * High mappings must be section aligned |
| */ |
| if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SECTION_MASK)) |
| return NULL; |
| |
| /* |
| * Don't allow RAM to be mapped |
| */ |
| if (pfn_valid(pfn)) { |
| printk(KERN_WARNING "BUG: Your driver calls ioremap() on\n" |
| "system memory. This leads to architecturally\n" |
| "unpredictable behaviour, and ioremap() will fail in\n" |
| "the next kernel release. Please fix your driver.\n"); |
| WARN_ON(1); |
| } |
| |
| type = get_mem_type(mtype); |
| if (!type) |
| return NULL; |
| |
| /* |
| * Page align the mapping size, taking account of any offset. |
| */ |
| size = PAGE_ALIGN(offset + size); |
| |
| area = get_vm_area_caller(size, VM_IOREMAP, caller); |
| if (!area) |
| return NULL; |
| addr = (unsigned long)area->addr; |
| |
| if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) { |
| area->flags |= VM_UNICORE_SECTION_MAPPING; |
| err = remap_area_sections(addr, pfn, size, type); |
| } else |
| err = ioremap_page_range(addr, addr + size, __pfn_to_phys(pfn), |
| __pgprot(type->prot_pte)); |
| |
| if (err) { |
| vunmap((void *)addr); |
| return NULL; |
| } |
| |
| flush_cache_vmap(addr, addr + size); |
| return (void __iomem *) (offset + addr); |
| } |
| |
| void __iomem *__uc32_ioremap_caller(unsigned long phys_addr, size_t size, |
| unsigned int mtype, void *caller) |
| { |
| unsigned long 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 __uc32_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 * |
| __uc32_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size, |
| unsigned int mtype) |
| { |
| return __uc32_ioremap_pfn_caller(pfn, offset, size, mtype, |
| __builtin_return_address(0)); |
| } |
| EXPORT_SYMBOL(__uc32_ioremap_pfn); |
| |
| void __iomem * |
| __uc32_ioremap(unsigned long phys_addr, size_t size) |
| { |
| return __uc32_ioremap_caller(phys_addr, size, MT_DEVICE, |
| __builtin_return_address(0)); |
| } |
| EXPORT_SYMBOL(__uc32_ioremap); |
| |
| void __iomem * |
| __uc32_ioremap_cached(unsigned long phys_addr, size_t size) |
| { |
| return __uc32_ioremap_caller(phys_addr, size, MT_DEVICE_CACHED, |
| __builtin_return_address(0)); |
| } |
| EXPORT_SYMBOL(__uc32_ioremap_cached); |
| |
| void __uc32_iounmap(volatile void __iomem *io_addr) |
| { |
| void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr); |
| struct vm_struct *vm; |
| |
| /* |
| * 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. We need the lock here b/c we need to clear |
| * all the mappings before the area can be reclaimed |
| * by someone else. |
| */ |
| vm = find_vm_area(addr); |
| if (vm && (vm->flags & VM_IOREMAP) && |
| (vm->flags & VM_UNICORE_SECTION_MAPPING)) |
| unmap_area_sections((unsigned long)vm->addr, vm->size); |
| |
| vunmap(addr); |
| } |
| EXPORT_SYMBOL(__uc32_iounmap); |