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| author | Ard Biesheuvel <ardb@kernel.org> | 2024-02-14 15:29:04 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2024-02-16 15:42:33 +0300 |
| commit | 97a6f43bb049e64b9913c50c7530e13d78e205d4 (patch) | |
| tree | f27badee5d092ecc09f221e6ce6dd19b83e9b44c /arch/arm64/kernel/head.S | |
| parent | 82ca151da7d54d7571c5d511d016b7780d5d559f (diff) | |
| download | linux-97a6f43bb049e64b9913c50c7530e13d78e205d4.tar.xz | |
arm64: head: Move early kernel mapping routines into C code
The asm version of the kernel mapping code works fine for creating a
coarse grained identity map, but for mapping the kernel down to its
exact boundaries with the right attributes, it is not suitable. This is
why we create a preliminary RWX kernel mapping first, and then rebuild
it from scratch later on.
So let's reimplement this in C, in a way that will make it unnecessary
to create the kernel page tables yet another time in paging_init().
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240214122845.2033971-63-ardb+git@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/head.S')
| -rw-r--r-- | arch/arm64/kernel/head.S | 52 |
1 files changed, 1 insertions, 51 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index aa7766dc64d9..ffacce7b5a02 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -81,7 +81,6 @@ * x20 primary_entry() .. __primary_switch() CPU boot mode * x21 primary_entry() .. start_kernel() FDT pointer passed at boot in x0 * x22 create_idmap() .. start_kernel() ID map VA of the DT blob - * x23 __primary_switch() physical misalignment/KASLR offset * x25 primary_entry() .. start_kernel() supported VA size * x28 create_idmap() callee preserved temp register */ @@ -408,24 +407,6 @@ SYM_FUNC_START_LOCAL(create_idmap) 0: ret x28 SYM_FUNC_END(create_idmap) -SYM_FUNC_START_LOCAL(create_kernel_mapping) - adrp x0, init_pg_dir - mov_q x5, KIMAGE_VADDR // compile time __va(_text) -#ifdef CONFIG_RELOCATABLE - add x5, x5, x23 // add KASLR displacement -#endif - adrp x6, _end // runtime __pa(_end) - adrp x3, _text // runtime __pa(_text) - sub x6, x6, x3 // _end - _text - add x6, x6, x5 // runtime __va(_end) - mov_q x7, SWAPPER_RW_MMUFLAGS - - map_memory x0, x1, x5, x6, x7, x3, (VA_BITS - PGDIR_SHIFT), x10, x11, x12, x13, x14 - - dsb ishst // sync with page table walker - ret -SYM_FUNC_END(create_kernel_mapping) - /* * Initialize CPU registers with task-specific and cpu-specific context. * @@ -752,44 +733,13 @@ SYM_FUNC_START_LOCAL(__primary_switch) adrp x2, init_idmap_pg_dir bl __enable_mmu - // Clear BSS - adrp x0, __bss_start - mov x1, xzr - adrp x2, init_pg_end - sub x2, x2, x0 - bl __pi_memset - dsb ishst // Make zero page visible to PTW - adrp x1, early_init_stack mov sp, x1 mov x29, xzr mov x0, x20 // pass the full boot status mov x1, x22 // pass the low FDT mapping - bl __pi_init_feature_override // Parse cpu feature overrides - -#ifdef CONFIG_RELOCATABLE - adrp x23, KERNEL_START - and x23, x23, MIN_KIMG_ALIGN - 1 -#ifdef CONFIG_RANDOMIZE_BASE - mov x0, x22 - bl __pi_kaslr_early_init - bic x0, x0, #SZ_2M - 1 - orr x23, x23, x0 // record kernel offset -#endif -#endif - bl create_kernel_mapping + bl __pi_early_map_kernel // Map and relocate the kernel - adrp x1, init_pg_dir - load_ttbr1 x1, x1, x2 -#ifdef CONFIG_RELOCATABLE - mov x0, x23 - bl __pi_relocate_kernel -#endif -#ifdef CONFIG_UNWIND_PATCH_PAC_INTO_SCS - ldr x0, =__eh_frame_start - ldr x1, =__eh_frame_end - bl __pi_scs_patch_vmlinux -#endif ldr x8, =__primary_switched adrp x0, KERNEL_START // __pa(KERNEL_START) br x8 |