Create initial page tables in init_pg_dir and then create final
page tables in swapper_pg_dir directly.
Signed-off-by: Jun Yao <yaojun8558...@gmail.com>
---
arch/arm64/include/asm/pgtable.h | 2 ++
arch/arm64/kernel/head.S | 9 ++++++---
arch/arm64/mm/mmu.c | 27 ++++++++-------------------
3 files changed, 16 insertions(+), 22 deletions(-)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 1bdeca8918a6..46ef21ebfe47 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -712,6 +712,8 @@ static inline pmd_t pmdp_establish(struct vm_area_struct
*vma,
}
#endif
+extern pgd_t init_pg_dir[PTRS_PER_PGD];
+extern pgd_t init_pg_end[];
extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
extern pgd_t swapper_pg_end[];
extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index c3e4b1886cde..ede2e964592b 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -376,7 +376,7 @@ __create_page_tables:
/*
* Map the kernel image (starting with PHYS_OFFSET).
*/
- adrp x0, swapper_pg_dir
+ adrp x0, init_pg_dir
mov_q x5, KIMAGE_VADDR + TEXT_OFFSET // compile time __va(_text)
add x5, x5, x23 // add KASLR displacement
mov x4, PTRS_PER_PGD
@@ -402,7 +402,6 @@ __create_page_tables:
adrp x1, init_pg_end
sub x1, x1, x0
bl __inval_dcache_area
-
ret x28
ENDPROC(__create_page_tables)
.ltorg
@@ -439,6 +438,9 @@ __primary_switched:
bl __pi_memset
dsb ishst // Make zero page visible to PTW
+ adrp x0, init_pg_dir
+ bl set_init_mm_pgd
+
#ifdef CONFIG_KASAN
bl kasan_early_init
#endif
@@ -833,8 +835,9 @@ __primary_switch:
mrs x20, sctlr_el1 // preserve old SCTLR_EL1 value
#endif
- adrp x1, swapper_pg_dir
+ adrp x1, init_pg_dir
bl __enable_mmu
+
#ifdef CONFIG_RELOCATABLE
bl __relocate_kernel
#ifdef CONFIG_RANDOMIZE_BASE
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 65f86271f02b..088a591e4ea4 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -629,26 +629,10 @@ static void __init map_kernel(pgd_t *pgdp)
*/
void __init paging_init(void)
{
- phys_addr_t pgd_phys = early_pgtable_alloc();
- pgd_t *pgdp = pgd_set_fixmap(pgd_phys);
-
- map_kernel(pgdp);
- map_mem(pgdp);
-
- /*
- * We want to reuse the original swapper_pg_dir so we don't have to
- * communicate the new address to non-coherent secondaries in
- * secondary_entry, and so cpu_switch_mm can generate the address with
- * adrp+add rather than a load from some global variable.
- *
- * To do this we need to go via a temporary pgd.
- */
- cpu_replace_ttbr1(__va(pgd_phys));
- memcpy(swapper_pg_dir, pgdp, PGD_SIZE);
+ map_kernel(swapper_pg_dir);
+ map_mem(swapper_pg_dir);
cpu_replace_ttbr1(lm_alias(swapper_pg_dir));
-
- pgd_clear_fixmap();
- memblock_free(pgd_phys, PAGE_SIZE);
+ init_mm.pgd = swapper_pg_dir;
/*
* We only reuse the PGD from the swapper_pg_dir, not the pud + pmd
@@ -659,6 +643,11 @@ void __init paging_init(void)
- PAGE_SIZE);
}
+void __init set_init_mm_pgd(pgd_t *pgd)
+{
+ init_mm.pgd = pgd;
+}
+
/*
* Check whether a kernel address is valid (derived from arch/x86/).
*/
--
2.17.1
