#include <asm/cacheflush.h>
#include <asm/io.h>
+#include <asm/mmu_context.h>
+#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
+#include <asm/sizes.h>
+
+/*
+ * Used by ioremap() and iounmap() code to mark 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,
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_kernel(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;
+}
+#endif
+
+
/*
* Remap an arbitrary physical address space into the kernel virtual
* address space. Needed when the kernel wants to access high addresses
__ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
unsigned long flags)
{
+ int err;
unsigned long addr;
struct vm_struct * area;
if (!area)
return NULL;
addr = (unsigned long)area->addr;
- if (remap_area_pages(addr, pfn, size, flags)) {
+
+#ifndef CONFIG_SMP
+ 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);
void __iounmap(void __iomem *addr)
{
- vunmap((void *)(PAGE_MASK & (unsigned long)addr));
+ struct vm_struct **p, *tmp;
+ unsigned int section_mapping = 0;
+
+ addr = (void __iomem *)(PAGE_MASK & (unsigned long)addr);
+
+ /*
+ * 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;
+ }
+ }
+ write_unlock(&vmlist_lock);
+
+ if (!section_mapping)
+ vunmap(addr);
}
EXPORT_SYMBOL(__iounmap);
projects / linux-2.6 / commitdiff