[S390] System z large page support.

[linux-2.6-omap-h63xx.git] / arch / s390 / mm / vmem.c

diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 3ffc0211dc85c68d0758966774a5f7e4e20ff3fe..97bce6c9757422c3a208b3f9b355f682db7f4b5f 100644 (file)
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -10,10 +10,12 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/list.h>
+#include <linux/hugetlb.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
 #include <asm/setup.h>
 #include <asm/tlbflush.h>
+#include <asm/sections.h>
 
 static DEFINE_MUTEX(vmem_mutex);
 
@@ -113,7 +115,7 @@ static pte_t __init_refok *vmem_pte_alloc(void)
 /*
  * Add a physical memory range to the 1:1 mapping.
  */
-static int vmem_add_range(unsigned long start, unsigned long size)
+static int vmem_add_range(unsigned long start, unsigned long size, int ro)
 {
        unsigned long address;
        pgd_t *pg_dir;
@@ -140,7 +142,19 @@ static int vmem_add_range(unsigned long start, unsigned long size)
                        pud_populate_kernel(&init_mm, pu_dir, pm_dir);
                }
 
+               pte = mk_pte_phys(address, __pgprot(ro ? _PAGE_RO : 0));
                pm_dir = pmd_offset(pu_dir, address);
+
+#ifdef __s390x__
+               if (MACHINE_HAS_HPAGE && !(address & ~HPAGE_MASK) &&
+                   (address + HPAGE_SIZE <= start + size) &&
+                   (address >= HPAGE_SIZE)) {
+                       pte_val(pte) |= _SEGMENT_ENTRY_LARGE;
+                       pmd_val(*pm_dir) = pte_val(pte);
+                       address += HPAGE_SIZE - PAGE_SIZE;
+                       continue;
+               }
+#endif
                if (pmd_none(*pm_dir)) {
                        pt_dir = vmem_pte_alloc();
                        if (!pt_dir)
@@ -149,7 +163,6 @@ static int vmem_add_range(unsigned long start, unsigned long size)
                }
 
                pt_dir = pte_offset_kernel(pm_dir, address);
-               pte = pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL);
                *pt_dir = pte;
        }
        ret = 0;
@@ -180,6 +193,13 @@ static void vmem_remove_range(unsigned long start, unsigned long size)
                pm_dir = pmd_offset(pu_dir, address);
                if (pmd_none(*pm_dir))
                        continue;
+
+               if (pmd_huge(*pm_dir)) {
+                       pmd_clear_kernel(pm_dir);
+                       address += HPAGE_SIZE - PAGE_SIZE;
+                       continue;
+               }
+
                pt_dir = pte_offset_kernel(pm_dir, address);
                *pt_dir = pte;
        }
@@ -248,14 +268,14 @@ out:
        return ret;
 }
 
-static int vmem_add_mem(unsigned long start, unsigned long size)
+static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
 {
        int ret;
 
        ret = vmem_add_mem_map(start, size);
        if (ret)
                return ret;
-       return vmem_add_range(start, size);
+       return vmem_add_range(start, size, ro);
 }
 
 /*
@@ -338,7 +358,7 @@ int add_shared_memory(unsigned long start, unsigned long size)
        if (ret)
                goto out_free;
 
-       ret = vmem_add_mem(start, size);
+       ret = vmem_add_mem(start, size, 0);
        if (ret)
                goto out_remove;
 
@@ -374,14 +394,35 @@ out:
  */
 void __init vmem_map_init(void)
 {
+       unsigned long ro_start, ro_end;
+       unsigned long start, end;
        int i;
 
        INIT_LIST_HEAD(&init_mm.context.crst_list);
        INIT_LIST_HEAD(&init_mm.context.pgtable_list);
        init_mm.context.noexec = 0;
        NODE_DATA(0)->node_mem_map = VMEM_MAP;
-       for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++)
-               vmem_add_mem(memory_chunk[i].addr, memory_chunk[i].size);
+       ro_start = ((unsigned long)&_stext) & PAGE_MASK;
+       ro_end = PFN_ALIGN((unsigned long)&_eshared);
+       for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
+               start = memory_chunk[i].addr;
+               end = memory_chunk[i].addr + memory_chunk[i].size;
+               if (start >= ro_end || end <= ro_start)
+                       vmem_add_mem(start, end - start, 0);
+               else if (start >= ro_start && end <= ro_end)
+                       vmem_add_mem(start, end - start, 1);
+               else if (start >= ro_start) {
+                       vmem_add_mem(start, ro_end - start, 1);
+                       vmem_add_mem(ro_end, end - ro_end, 0);
+               } else if (end < ro_end) {
+                       vmem_add_mem(start, ro_start - start, 0);
+                       vmem_add_mem(ro_start, end - ro_start, 1);
+               } else {
+                       vmem_add_mem(start, ro_start - start, 0);
+                       vmem_add_mem(ro_start, ro_end - ro_start, 1);
+                       vmem_add_mem(ro_end, end - ro_end, 0);
+               }
+       }
 }
 
 /*