1 files changed, 67 insertions, 10 deletions

diff --git a/drivers/acpi/atomicio.c b/drivers/acpi/atomicio.c
index cfc0cc10af39..d4a5b3d3657b 100644
--- a/drivers/acpi/atomicio.c
+++ b/drivers/acpi/atomicio.c
@@ -32,6 +32,8 @@
 #include <linux/rculist.h>
 #include <linux/interrupt.h>
 #include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
 #include <acpi/atomicio.h>
 
 #define ACPI_PFX "ACPI: "
@@ -97,6 +99,37 @@ static void __iomem *__acpi_try_ioremap(phys_addr_t paddr,
                 return NULL;
 }
 
+#ifndef CONFIG_IA64
+#define should_use_kmap(pfn)    page_is_ram(pfn)
+#else
+/* ioremap will take care of cache attributes */
+#define should_use_kmap(pfn)    0
+#endif
+
+static void __iomem *acpi_map(phys_addr_t pg_off, unsigned long pg_sz)
+{
+        unsigned long pfn;
+
+        pfn = pg_off >> PAGE_SHIFT;
+        if (should_use_kmap(pfn)) {
+                if (pg_sz > PAGE_SIZE)
+                        return NULL;
+                return (void __iomem __force *)kmap(pfn_to_page(pfn));
+        } else
+                return ioremap(pg_off, pg_sz);
+}
+
+static void acpi_unmap(phys_addr_t pg_off, void __iomem *vaddr)
+{
+        unsigned long pfn;
+
+        pfn = pg_off >> PAGE_SHIFT;
+        if (page_is_ram(pfn))
+                kunmap(pfn_to_page(pfn));
+        else
+                iounmap(vaddr);
+}
+
 /*
  * Used to pre-map the specified IO memory area. First try to find
  * whether the area is already pre-mapped, if it is, increase the
@@ -119,7 +152,7 @@ static void __iomem *acpi_pre_map(phys_addr_t paddr,
 
         pg_off = paddr & PAGE_MASK;
         pg_sz = ((paddr + size + PAGE_SIZE - 1) & PAGE_MASK) - pg_off;
-        vaddr = ioremap(pg_off, pg_sz);
+        vaddr = acpi_map(pg_off, pg_sz);
         if (!vaddr)
                 return NULL;
         map = kmalloc(sizeof(*map), GFP_KERNEL);
@@ -135,7 +168,7 @@ static void __iomem *acpi_pre_map(phys_addr_t paddr,
         vaddr = __acpi_try_ioremap(paddr, size);
         if (vaddr) {
                 spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
-                iounmap(map->vaddr);
+                acpi_unmap(pg_off, map->vaddr);
                 kfree(map);
                 return vaddr;
         }
@@ -144,7 +177,7 @@ static void __iomem *acpi_pre_map(phys_addr_t paddr,
 
         return map->vaddr + (paddr - map->paddr);
 err_unmap:
-        iounmap(vaddr);
+        acpi_unmap(pg_off, vaddr);
         return NULL;
 }
 
@@ -177,7 +210,7 @@ static void acpi_post_unmap(phys_addr_t paddr, unsigned long size)
                 return;
 
         synchronize_rcu();
-        iounmap(map->vaddr);
+        acpi_unmap(map->paddr, map->vaddr);
         kfree(map);
 }
 
@@ -260,6 +293,21 @@ int acpi_post_unmap_gar(struct acpi_generic_address *reg)
 }
 EXPORT_SYMBOL_GPL(acpi_post_unmap_gar);
 
+#ifdef readq
+static inline u64 read64(const volatile void __iomem *addr)
+{
+        return readq(addr);
+}
+#else
+static inline u64 read64(const volatile void __iomem *addr)
+{
+        u64 l, h;
+        l = readl(addr);
+        h = readl(addr+4);
+        return l | (h << 32);
+}
+#endif
+
 /*
  * Can be used in atomic (including NMI) or process context. RCU read
  * lock can only be released after the IO memory area accessing.
@@ -280,11 +328,9 @@ static int acpi_atomic_read_mem(u64 paddr, u64 *val, u32 width)
         case 32:
                 *val = readl(addr);
                 break;
-#ifdef readq
         case 64:
-                *val = readq(addr);
+                *val = read64(addr);
                 break;
-#endif
         default:
                 return -EINVAL;
         }
@@ -293,6 +339,19 @@ static int acpi_atomic_read_mem(u64 paddr, u64 *val, u32 width)
         return 0;
 }
 
+#ifdef writeq
+static inline void write64(u64 val, volatile void __iomem *addr)
+{
+        writeq(val, addr);
+}
+#else
+static inline void write64(u64 val, volatile void __iomem *addr)
+{
+        writel(val, addr);
+        writel(val>>32, addr+4);
+}
+#endif
+
 static int acpi_atomic_write_mem(u64 paddr, u64 val, u32 width)
 {
         void __iomem *addr;
@@ -309,11 +368,9 @@ static int acpi_atomic_write_mem(u64 paddr, u64 val, u32 width)
         case 32:
                 writel(val, addr);
                 break;
-#ifdef writeq
         case 64:
-                writeq(val, addr);
+                write64(val, addr);
                 break;
-#endif
         default:
                 return -EINVAL;
         }