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authorFathi Boudra <fathi.boudra@linaro.org>2013-05-23 14:08:13 +0300
committerFathi Boudra <fathi.boudra@linaro.org>2013-05-23 14:08:13 +0300
commitf7ae240ea162f1bf80c2f9d58e42fac888f4320b (patch)
tree546429c54a94bf165766731085b77861f1e5b700 /arch/x86/mm/highmem_32.c
Initial commit - add 3.8.13 mainline
Signed-off-by: Fathi Boudra <fathi.boudra@linaro.org>
Diffstat (limited to 'arch/x86/mm/highmem_32.c')
-rw-r--r--arch/x86/mm/highmem_32.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
new file mode 100644
index 00000000..6f31ee56
--- /dev/null
+++ b/arch/x86/mm/highmem_32.c
@@ -0,0 +1,141 @@
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <linux/swap.h> /* for totalram_pages */
+
+void *kmap(struct page *page)
+{
+ might_sleep();
+ if (!PageHighMem(page))
+ return page_address(page);
+ return kmap_high(page);
+}
+EXPORT_SYMBOL(kmap);
+
+void kunmap(struct page *page)
+{
+ if (in_interrupt())
+ BUG();
+ if (!PageHighMem(page))
+ return;
+ kunmap_high(page);
+}
+EXPORT_SYMBOL(kunmap);
+
+/*
+ * 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 it is not legal to sleep, so atomic
+ * kmaps are appropriate for short, tight code paths only.
+ */
+void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+ unsigned long vaddr;
+ int idx, type;
+
+ /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
+ pagefault_disable();
+
+ if (!PageHighMem(page))
+ return page_address(page);
+
+ type = kmap_atomic_idx_push();
+ 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;
+}
+EXPORT_SYMBOL(kmap_atomic_prot);
+
+void *kmap_atomic(struct page *page)
+{
+ return kmap_atomic_prot(page, kmap_prot);
+}
+EXPORT_SYMBOL(kmap_atomic);
+
+/*
+ * 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)
+{
+ return kmap_atomic_prot_pfn(pfn, kmap_prot);
+}
+EXPORT_SYMBOL_GPL(kmap_atomic_pfn);
+
+void __kunmap_atomic(void *kvaddr)
+{
+ unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
+
+ if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
+ vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
+ int idx, type;
+
+ type = kmap_atomic_idx();
+ idx = type + KM_TYPE_NR * smp_processor_id();
+
+#ifdef CONFIG_DEBUG_HIGHMEM
+ WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
+#endif
+ /*
+ * 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.
+ */
+ kpte_clear_flush(kmap_pte-idx, vaddr);
+ kmap_atomic_idx_pop();
+ arch_flush_lazy_mmu_mode();
+ }
+#ifdef CONFIG_DEBUG_HIGHMEM
+ else {
+ BUG_ON(vaddr < PAGE_OFFSET);
+ BUG_ON(vaddr >= (unsigned long)high_memory);
+ }
+#endif
+
+ pagefault_enable();
+}
+EXPORT_SYMBOL(__kunmap_atomic);
+
+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_atomic_to_page);
+
+void __init set_highmem_pages_init(void)
+{
+ struct zone *zone;
+ int nid;
+
+ for_each_zone(zone) {
+ unsigned long zone_start_pfn, zone_end_pfn;
+
+ if (!is_highmem(zone))
+ continue;
+
+ zone_start_pfn = zone->zone_start_pfn;
+ zone_end_pfn = zone_start_pfn + zone->spanned_pages;
+
+ nid = zone_to_nid(zone);
+ printk(KERN_INFO "Initializing %s for node %d (%08lx:%08lx)\n",
+ zone->name, nid, zone_start_pfn, zone_end_pfn);
+
+ add_highpages_with_active_regions(nid, zone_start_pfn,
+ zone_end_pfn);
+ }
+ totalram_pages += totalhigh_pages;
+}