[PATCH v2 16/34] ARM: mmu32: implement zero_page_*()

[Sascha Hauer <s.hauer@pengutronix.de>]

We have functions to access the zero page and to make it faulting again.
Implement them for AArch32.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 arch/arm/cpu/Kconfig      |  3 ++-
 arch/arm/cpu/mmu-common.c | 11 +++++++++++
 arch/arm/cpu/mmu_32.c     |  5 ++---
 arch/arm/cpu/mmu_64.c     | 10 ----------
 4 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/arch/arm/cpu/Kconfig b/arch/arm/cpu/Kconfig
index 26f07043fe..40dd35833a 100644
--- a/arch/arm/cpu/Kconfig
+++ b/arch/arm/cpu/Kconfig
@@ -11,6 +11,7 @@ config CPU_32
 	select HAVE_MOD_ARCH_SPECIFIC
 	select HAS_DMA
 	select HAVE_PBL_IMAGE
+	select ARCH_HAS_ZERO_PAGE
 
 config CPU_64
 	bool
@@ -19,6 +20,7 @@ config CPU_64
 	select HAVE_PBL_MULTI_IMAGES
 	select HAS_DMA
 	select ARCH_WANT_FRAME_POINTERS
+	select ARCH_HAS_ZERO_PAGE
 
 # Select CPU types depending on the architecture selected. This selects
 # which CPUs we support in the kernel image, and the compiler instruction
@@ -92,7 +94,6 @@ config CPU_V8
 	select ARM_EXCEPTIONS
 	select GENERIC_FIND_NEXT_BIT
 	select ARCH_HAS_STACK_DUMP
-	select ARCH_HAS_ZERO_PAGE
 
 config CPU_XSC3
         bool
diff --git a/arch/arm/cpu/mmu-common.c b/arch/arm/cpu/mmu-common.c
index e6cc3b974f..02f512c2c6 100644
--- a/arch/arm/cpu/mmu-common.c
+++ b/arch/arm/cpu/mmu-common.c
@@ -11,6 +11,7 @@
 #include <asm/system.h>
 #include <asm/barebox-arm.h>
 #include <memory.h>
+#include <zero_page.h>
 #include "mmu-common.h"
 
 void dma_sync_single_for_cpu(dma_addr_t address, size_t size,
@@ -57,6 +58,16 @@ void dma_free_coherent(void *mem, dma_addr_t dma_handle, size_t size)
 	free(mem);
 }
 
+void zero_page_access(void)
+{
+	arch_remap_range(0x0, PAGE_SIZE, MAP_CACHED);
+}
+
+void zero_page_faulting(void)
+{
+	arch_remap_range(0x0, PAGE_SIZE, MAP_FAULT);
+}
+
 static int mmu_init(void)
 {
 	if (list_empty(&memory_banks)) {
diff --git a/arch/arm/cpu/mmu_32.c b/arch/arm/cpu/mmu_32.c
index a1ecc49f03..7b31938ecd 100644
--- a/arch/arm/cpu/mmu_32.c
+++ b/arch/arm/cpu/mmu_32.c
@@ -9,6 +9,7 @@
 #include <init.h>
 #include <mmu.h>
 #include <errno.h>
+#include <zero_page.h>
 #include <linux/sizes.h>
 #include <asm/memory.h>
 #include <asm/barebox-arm.h>
@@ -362,7 +363,6 @@ static int set_vector_table(unsigned long adr)
 static void create_zero_page(void)
 {
 	struct resource *zero_sdram;
-	u32 *zero;
 
 	zero_sdram = request_sdram_region("zero page", 0x0, PAGE_SIZE);
 	if (zero_sdram) {
@@ -372,8 +372,7 @@ static void create_zero_page(void)
 		 */
 		pr_debug("zero page is in SDRAM area, currently not supported\n");
 	} else {
-		zero = arm_create_pte(0x0, pte_flags_uncached);
-		zero[0] = 0;
+		zero_page_faulting();
 		pr_debug("Created zero page\n");
 	}
 }
diff --git a/arch/arm/cpu/mmu_64.c b/arch/arm/cpu/mmu_64.c
index 0639d0f1ce..c7c16b527b 100644
--- a/arch/arm/cpu/mmu_64.c
+++ b/arch/arm/cpu/mmu_64.c
@@ -172,16 +172,6 @@ static void mmu_enable(void)
 	set_cr(get_cr() | CR_M | CR_C | CR_I);
 }
 
-void zero_page_access(void)
-{
-	arch_remap_range(0x0, PAGE_SIZE, MAP_CACHED);
-}
-
-void zero_page_faulting(void)
-{
-	arch_remap_range(0x0, PAGE_SIZE, MAP_FAULT);
-}
-
 /*
  * Prepare MMU for usage enable it.
  */
-- 
2.39.2