s390/vmem: simplify vmem code for read-only mappings

For the kernel identity mapping map everything read-writeable and
subsequently call set_memory_ro() to make the ro section read-only.
This simplifies the code a lot.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 0a7b03496f67848d2994350be1c5c5edb3a93f12..b200f976c36bc64e42b65ea4a2d81a3a7821c54c 100644 (file)
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -11,6 +11,7 @@
 #include <linux/hugetlb.h>
 #include <linux/slab.h>
 #include <linux/memblock.h>
+#include <asm/cacheflush.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
 #include <asm/setup.h>
@@ -77,7 +78,7 @@ pte_t __ref *vmem_pte_alloc(void)
 /*
  * Add a physical memory range to the 1:1 mapping.
  */
-static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
+static int vmem_add_mem(unsigned long start, unsigned long size)
 {
        unsigned long end = start + size;
        unsigned long address = start;
@@ -99,8 +100,7 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
                if (MACHINE_HAS_EDAT2 && pud_none(*pu_dir) && address &&
                    !(address & ~PUD_MASK) && (address + PUD_SIZE <= end) &&
                     !debug_pagealloc_enabled()) {
-                       pud_val(*pu_dir) = address |
-                               pgprot_val(ro ? REGION3_KERNEL_RO : REGION3_KERNEL);
+                       pud_val(*pu_dir) = address | pgprot_val(REGION3_KERNEL);
                        address += PUD_SIZE;
                        continue;
                }
@@ -114,8 +114,7 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
                if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address &&
                    !(address & ~PMD_MASK) && (address + PMD_SIZE <= end) &&
                    !debug_pagealloc_enabled()) {
-                       pmd_val(*pm_dir) = address |
-                               pgprot_val(ro ? SEGMENT_KERNEL_RO : SEGMENT_KERNEL);
+                       pmd_val(*pm_dir) = address | pgprot_val(SEGMENT_KERNEL);
                        address += PMD_SIZE;
                        continue;
                }
@@ -127,8 +126,7 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
                }
 
                pt_dir = pte_offset_kernel(pm_dir, address);
-               pte_val(*pt_dir) = address |
-                       pgprot_val(ro ? PAGE_KERNEL_RO : PAGE_KERNEL);
+               pte_val(*pt_dir) = address |  pgprot_val(PAGE_KERNEL);
                address += PAGE_SIZE;
        }
        ret = 0;
@@ -338,7 +336,7 @@ int vmem_add_mapping(unsigned long start, unsigned long size)
        if (ret)
                goto out_free;
 
-       ret = vmem_add_mem(start, size, 0);
+       ret = vmem_add_mem(start, size);
        if (ret)
                goto out_remove;
        goto out;
@@ -361,29 +359,12 @@ void __init vmem_map_init(void)
 {
        unsigned long ro_start, ro_end;
        struct memblock_region *reg;
-       phys_addr_t start, end;
 
+       for_each_memblock(memory, reg)
+               vmem_add_mem(reg->base, reg->size);
        ro_start = PFN_ALIGN((unsigned long)&_stext);
        ro_end = (unsigned long)&_eshared & PAGE_MASK;
-       for_each_memblock(memory, reg) {
-               start = reg->base;
-               end = reg->base + reg->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);
-               }
-       }
+       set_memory_ro(ro_start, (ro_end - ro_start) >> PAGE_SHIFT);
 }
 
 /*