X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=arch%2Farm%2Fmm%2Fioremap.c;h=46544059279132efb3b3112f95929912f700f004;hb=24fcbacedb0d83cabc6761acbecfbf751265ce52;hp=c1f7180c7beda07ff35d3211880902b8a83c2a2c;hpb=36a557d1f48669c57f59e37d9334400a29e4e53c;p=linux-2.6-omap-h63xx.git diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c index c1f7180c7be..46544059279 100644 --- a/arch/arm/mm/ioremap.c +++ b/arch/arm/mm/ioremap.c @@ -27,7 +27,16 @@ #include #include +#include +#include #include +#include + +/* + * Used by ioremap() and iounmap() code to mark (super)section-mapped + * I/O regions in vm_struct->flags field. + */ +#define VM_ARM_SECTION_MAPPING 0x80000000 static inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size, @@ -113,10 +122,168 @@ remap_area_pages(unsigned long start, unsigned long pfn, dir++; } while (address && (address < end)); - flush_cache_vmap(start, end); return err; } + +void __check_kvm_seq(struct mm_struct *mm) +{ + unsigned int seq; + + do { + seq = init_mm.context.kvm_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.kvm_seq = seq; + } while (seq != init_mm.context.kvm_seq); +} + +#ifndef CONFIG_SMP +/* + * 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() 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); + pgd_t *pgd; + + flush_cache_vunmap(addr, end); + pgd = pgd_offset_k(addr); + do { + pmd_t pmd, *pmdp = pmd_offset(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); + init_mm.context.kvm_seq++; + + /* + * Free the page table, if there was one. + */ + if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE) + pte_free_kernel(pmd_page_vaddr(pmd)); + } + + addr += PGDIR_SIZE; + pgd++; + } 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.kvm_seq != init_mm.context.kvm_seq) + __check_kvm_seq(current->active_mm); + + flush_tlb_kernel_range(virt, end); +} + +static int +remap_area_sections(unsigned long virt, unsigned long pfn, + unsigned long size, unsigned long flags) +{ + unsigned long prot, 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); + + prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_DOMAIN(DOMAIN_IO) | + (flags & (L_PTE_CACHEABLE | L_PTE_BUFFERABLE)); + + /* + * ARMv6 and above need XN set to prevent speculative prefetches + * hitting IO. + */ + if (cpu_architecture() >= CPU_ARCH_ARMv6) + prot |= PMD_SECT_XN; + + pgd = pgd_offset_k(addr); + do { + pmd_t *pmd = pmd_offset(pgd, addr); + + pmd[0] = __pmd(__pfn_to_phys(pfn) | prot); + pfn += SZ_1M >> PAGE_SHIFT; + pmd[1] = __pmd(__pfn_to_phys(pfn) | prot); + pfn += SZ_1M >> PAGE_SHIFT; + flush_pmd_entry(pmd); + + addr += PGDIR_SIZE; + pgd++; + } while (addr < end); + + return 0; +} + +static int +remap_area_supersections(unsigned long virt, unsigned long pfn, + unsigned long size, unsigned long flags) +{ + unsigned long prot, 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); + + prot = PMD_TYPE_SECT | PMD_SECT_SUPER | PMD_SECT_AP_WRITE | + PMD_DOMAIN(DOMAIN_IO) | + (flags & (L_PTE_CACHEABLE | L_PTE_BUFFERABLE)); + + /* + * ARMv6 and above need XN set to prevent speculative prefetches + * hitting IO. + */ + if (cpu_architecture() >= CPU_ARCH_ARMv6) + prot |= PMD_SECT_XN; + + pgd = pgd_offset_k(virt); + do { + unsigned long super_pmd_val, i; + + super_pmd_val = __pfn_to_phys(pfn) | prot; + super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20; + + for (i = 0; i < 8; i++) { + pmd_t *pmd = pmd_offset(pgd, addr); + + pmd[0] = __pmd(super_pmd_val); + pmd[1] = __pmd(super_pmd_val); + flush_pmd_entry(pmd); + + addr += PGDIR_SIZE; + pgd++; + } + + pfn += SUPERSECTION_SIZE >> PAGE_SHIFT; + } while (addr < end); + + return 0; +} +#endif + + /* * Remap an arbitrary physical address space into the kernel virtual * address space. Needed when the kernel wants to access high addresses @@ -133,18 +300,41 @@ void __iomem * __ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size, unsigned long flags) { + int err; unsigned long addr; struct vm_struct * area; + /* + * High mappings must be supersection aligned + */ + if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK)) + return NULL; + area = get_vm_area(size, VM_IOREMAP); if (!area) return NULL; addr = (unsigned long)area->addr; - if (remap_area_pages(addr, pfn, size, flags)) { + +#ifndef CONFIG_SMP + if ((((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) || + cpu_is_xsc3()) && + !((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) { + area->flags |= VM_ARM_SECTION_MAPPING; + err = remap_area_supersections(addr, pfn, size, flags); + } else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) { + area->flags |= VM_ARM_SECTION_MAPPING; + err = remap_area_sections(addr, pfn, size, flags); + } else +#endif + err = remap_area_pages(addr, pfn, size, flags); + + if (err) { vunmap((void *)addr); return NULL; } - return (void __iomem *) (offset + (char *)addr); + + flush_cache_vmap(addr, addr + size); + return (void __iomem *) (offset + addr); } EXPORT_SYMBOL(__ioremap_pfn); @@ -171,55 +361,40 @@ __ioremap(unsigned long phys_addr, size_t size, unsigned long flags) } EXPORT_SYMBOL(__ioremap); -void __iounmap(void __iomem *addr) -{ - vunmap((void *)(PAGE_MASK & (unsigned long)addr)); -} -EXPORT_SYMBOL(__iounmap); - -#ifdef __io -void __iomem *ioport_map(unsigned long port, unsigned int nr) -{ - return __io(port); -} -EXPORT_SYMBOL(ioport_map); - -void ioport_unmap(void __iomem *addr) +void __iounmap(volatile void __iomem *addr) { -} -EXPORT_SYMBOL(ioport_unmap); +#ifndef CONFIG_SMP + struct vm_struct **p, *tmp; #endif + unsigned int section_mapping = 0; -#ifdef CONFIG_PCI -#include -#include + addr = (volatile void __iomem *)(PAGE_MASK & (unsigned long)addr); -void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) -{ - unsigned long start = pci_resource_start(dev, bar); - unsigned long len = pci_resource_len(dev, bar); - unsigned long flags = pci_resource_flags(dev, bar); - - if (!len || !start) - return NULL; - if (maxlen && len > maxlen) - len = maxlen; - if (flags & IORESOURCE_IO) - return ioport_map(start, len); - if (flags & IORESOURCE_MEM) { - if (flags & IORESOURCE_CACHEABLE) - return ioremap(start, len); - return ioremap_nocache(start, len); +#ifndef CONFIG_SMP + /* + * If this is a section based mapping we need to handle it + * specially as the VM subysystem 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. + */ + write_lock(&vmlist_lock); + for (p = &vmlist ; (tmp = *p) ; p = &tmp->next) { + if((tmp->flags & VM_IOREMAP) && (tmp->addr == addr)) { + if (tmp->flags & VM_ARM_SECTION_MAPPING) { + *p = tmp->next; + unmap_area_sections((unsigned long)tmp->addr, + tmp->size); + kfree(tmp); + section_mapping = 1; + } + break; + } } - return NULL; -} -EXPORT_SYMBOL(pci_iomap); + write_unlock(&vmlist_lock); +#endif -void pci_iounmap(struct pci_dev *dev, void __iomem *addr) -{ - if ((unsigned long)addr >= VMALLOC_START && - (unsigned long)addr < VMALLOC_END) - iounmap(addr); + if (!section_mapping) + vunmap((void __force *)addr); } -EXPORT_SYMBOL(pci_iounmap); -#endif +EXPORT_SYMBOL(__iounmap);