i386: move mm

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 113 insertions, 0 deletions

diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
new file mode 100644
index 000000000000..1c3bf95f7356
--- /dev/null
+++ b/arch/x86/mm/highmem_32.c
@@ -0,0 +1,113 @@
+#include <linux/highmem.h>
+#include <linux/module.h>
+
+void *kmap(struct page *page)
+{
+        might_sleep();
+        if (!PageHighMem(page))
+                return page_address(page);
+        return kmap_high(page);
+}
+
+void kunmap(struct page *page)
+{
+        if (in_interrupt())
+                BUG();
+        if (!PageHighMem(page))
+                return;
+        kunmap_high(page);
+}
+
+/*
+ * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
+ * no global lock is needed and because the kmap code must perform a global TLB
+ * invalidation when the kmap pool wraps.
+ *
+ * However when holding an atomic kmap is is not legal to sleep, so atomic
+ * kmaps are appropriate for short, tight code paths only.
+ */
+void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
+{
+        enum fixed_addresses idx;
+        unsigned long vaddr;
+
+        /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+        pagefault_disable();
+
+        if (!PageHighMem(page))
+                return page_address(page);
+
+        idx = type + KM_TYPE_NR*smp_processor_id();
+        vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+        BUG_ON(!pte_none(*(kmap_pte-idx)));
+        set_pte(kmap_pte-idx, mk_pte(page, prot));
+        arch_flush_lazy_mmu_mode();
+
+        return (void *)vaddr;
+}
+
+void *kmap_atomic(struct page *page, enum km_type type)
+{
+        return kmap_atomic_prot(page, type, kmap_prot);
+}
+
+void kunmap_atomic(void *kvaddr, enum km_type type)
+{
+        unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
+        enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
+
+        /*
+         * Force other mappings to Oops if they'll try to access this pte
+         * without first remap it.  Keeping stale mappings around is a bad idea
+         * also, in case the page changes cacheability attributes or becomes
+         * a protected page in a hypervisor.
+         */
+        if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx))
+                kpte_clear_flush(kmap_pte-idx, vaddr);
+        else {
+#ifdef CONFIG_DEBUG_HIGHMEM
+                BUG_ON(vaddr < PAGE_OFFSET);
+                BUG_ON(vaddr >= (unsigned long)high_memory);
+#endif
+        }
+
+        arch_flush_lazy_mmu_mode();
+        pagefault_enable();
+}
+
+/* This is the same as kmap_atomic() but can map memory that doesn't
+ * have a struct page associated with it.
+ */
+void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
+{
+        enum fixed_addresses idx;
+        unsigned long vaddr;
+
+        pagefault_disable();
+
+        idx = type + KM_TYPE_NR*smp_processor_id();
+        vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
+        set_pte(kmap_pte-idx, pfn_pte(pfn, kmap_prot));
+        arch_flush_lazy_mmu_mode();
+
+        return (void*) vaddr;
+}
+
+struct page *kmap_atomic_to_page(void *ptr)
+{
+        unsigned long idx, vaddr = (unsigned long)ptr;
+        pte_t *pte;
+
+        if (vaddr < FIXADDR_START)
+                return virt_to_page(ptr);
+
+        idx = virt_to_fix(vaddr);
+        pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
+        return pte_page(*pte);
+}
+
+EXPORT_SYMBOL(kmap);
+EXPORT_SYMBOL(kunmap);
+EXPORT_SYMBOL(kmap_atomic);
+EXPORT_SYMBOL(kunmap_atomic);
+EXPORT_SYMBOL(kmap_atomic_to_page);