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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-08 03:43:32 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-08 03:43:32 +0000
commitf530fbb7a18f2794e4178dfb7cd07719b9586147 (patch)
tree3f704b17427743e26452771cf7da2ed110346ddd /arch/arm/mm/nommu.c
parentAdding debian version 4.19.260-1. (diff)
downloadlinux-f530fbb7a18f2794e4178dfb7cd07719b9586147.tar.xz
linux-f530fbb7a18f2794e4178dfb7cd07719b9586147.zip
Merging upstream version 4.19.269.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/mm/nommu.c')
-rw-r--r--arch/arm/mm/nommu.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c
index 7d67c70bb..e803fd162 100644
--- a/arch/arm/mm/nommu.c
+++ b/arch/arm/mm/nommu.c
@@ -25,6 +25,13 @@
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
@@ -147,9 +154,21 @@ 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 = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+ if (!zero_page)
+ panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+ __func__, PAGE_SIZE, PAGE_SIZE);
+
bootmem_init();
+
+ empty_zero_page = virt_to_page(zero_page);
+ flush_dcache_page(empty_zero_page);
}
/*