From bab247ff5f669216e3ed2f9a4034c540187e874c Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Tue, 10 May 2016 16:28:28 +0200
Subject: [PATCH] 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>
---
arch/s390/mm/vmem.c | 37 +++++++++----------------------------
1 file changed, 9 insertions(+), 28 deletions(-)
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 0a7b03496f678..b200f976c36bc 100644
--- 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);
}
/*
--
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