1 files changed, 24 insertions, 14 deletions

diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c
index 8b3d7191e2b8..d638cc87807e 100644
--- a/arch/arm/mm/nommu.c
+++ b/arch/arm/mm/nommu.c
@@ -21,11 +21,19 @@
 #include <asm/cputype.h>
 #include <asm/mpu.h>
 #include <asm/procinfo.h>
+#include <asm/idmap.h>
 
 #include "mm.h"
 
 unsigned long vectors_base;
 
+/*
+ * empty_zero_page is a special page that is used for
+ * zero-initialized data and COW.
+ */
+struct page *empty_zero_page;
+EXPORT_SYMBOL(empty_zero_page);
+
 #ifdef CONFIG_ARM_MPU
 struct mpu_rgn_info mpu_rgn_info;
 #endif
@@ -148,9 +156,18 @@ void __init adjust_lowmem_bounds(void)
  */
 void __init paging_init(const struct machine_desc *mdesc)
 {
+	void *zero_page;
+
 	early_trap_init((void *)vectors_base);
 	mpu_setup();
+
+	/* allocate the zero page. */
+	zero_page = (void *)memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
+
 	bootmem_init();
+
+	empty_zero_page = virt_to_page(zero_page);
+	flush_dcache_page(empty_zero_page);
 }
 
 /*
@@ -160,17 +177,17 @@ void setup_mm_for_reboot(void)
 {
 }
 
-void flush_dcache_page(struct page *page)
+void flush_dcache_folio(struct folio *folio)
 {
-	__cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
+	__cpuc_flush_dcache_area(folio_address(folio), folio_size(folio));
 }
-EXPORT_SYMBOL(flush_dcache_page);
+EXPORT_SYMBOL(flush_dcache_folio);
 
-void flush_kernel_dcache_page(struct page *page)
+void flush_dcache_page(struct page *page)
 {
 	__cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
 }
-EXPORT_SYMBOL(flush_kernel_dcache_page);
+EXPORT_SYMBOL(flush_dcache_page);
 
 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
 		       unsigned long uaddr, void *dst, const void *src,
@@ -231,19 +248,12 @@ void __iomem *pci_remap_cfgspace(resource_size_t res_cookie, size_t size)
 EXPORT_SYMBOL_GPL(pci_remap_cfgspace);
 #endif
 
-void *arch_memremap_wb(phys_addr_t phys_addr, size_t size)
+void *arch_memremap_wb(phys_addr_t phys_addr, size_t size, unsigned long flags)
 {
 	return (void *)phys_addr;
 }
 
-void __iounmap(volatile void __iomem *addr)
-{
-}
-EXPORT_SYMBOL(__iounmap);
-
-void (*arch_iounmap)(volatile void __iomem *);
-
-void iounmap(volatile void __iomem *addr)
+void iounmap(volatile void __iomem *io_addr)
 {
 }
 EXPORT_SYMBOL(iounmap);