arm64: move early boot code to the .init segment

Apart from the arm64/linux and EFI header data structures, there is nothing
in the .head.text section that must reside at the beginning of the Image.
So let's move it to the .init section where it belongs.

Note that this involves some minor tweaking of the EFI header, primarily
because the address of 'stext' no longer coincides with the start of the
.text section. It also requires a couple of relocated symbol references
to be slightly rewritten or their definition moved to the linker script.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit 546c8c44f092b2f23291fe499c221efc8cabbb67)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

diff --git a/arch/arm64/kernel/efi-entry.S b/arch/arm64/kernel/efi-entry.S
index f82036e02485a0abe27349e3ec76a00a491f7450..936022f0655e9ff3dce703c46adc2901118c6b82 100644 (file)
--- a/arch/arm64/kernel/efi-entry.S
+++ b/arch/arm64/kernel/efi-entry.S
@@ -61,7 +61,7 @@ ENTRY(entry)
         */
        mov     x20, x0         // DTB address
        ldr     x0, [sp, #16]   // relocated _text address
-       movz    x21, #:abs_g0:stext_offset
+       ldr     w21, =stext_offset
        add     x21, x0, x21
 
        /*

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index a88a15447c3bb382970a940b39fb9d6e0e6b9529..a9d4a0b882d7c4ca35a37d6ef27548b88515e5b0 100644 (file)
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -100,8 +100,6 @@ _head:
 #endif
 
 #ifdef CONFIG_EFI
-       .globl  __efistub_stext_offset
-       .set    __efistub_stext_offset, stext - _head
        .align 3
 pe_header:
        .ascii  "PE"
@@ -121,11 +119,11 @@ optional_header:
        .short  0x20b                           // PE32+ format
        .byte   0x02                            // MajorLinkerVersion
        .byte   0x14                            // MinorLinkerVersion
-       .long   _end - stext                    // SizeOfCode
+       .long   _end - efi_header_end           // SizeOfCode
        .long   0                               // SizeOfInitializedData
        .long   0                               // SizeOfUninitializedData
        .long   __efistub_entry - _head         // AddressOfEntryPoint
-       .long   __efistub_stext_offset          // BaseOfCode
+       .long   efi_header_end - _head          // BaseOfCode
 
 extra_header_fields:
        .quad   0                               // ImageBase
@@ -142,7 +140,7 @@ extra_header_fields:
        .long   _end - _head                    // SizeOfImage
 
        // Everything before the kernel image is considered part of the header
-       .long   __efistub_stext_offset          // SizeOfHeaders
+       .long   efi_header_end - _head          // SizeOfHeaders
        .long   0                               // CheckSum
        .short  0xa                             // Subsystem (EFI application)
        .short  0                               // DllCharacteristics
@@ -186,10 +184,10 @@ section_table:
        .byte   0
        .byte   0
        .byte   0                       // end of 0 padding of section name
-       .long   _end - stext            // VirtualSize
-       .long   __efistub_stext_offset  // VirtualAddress
-       .long   _edata - stext          // SizeOfRawData
-       .long   __efistub_stext_offset  // PointerToRawData
+       .long   _end - efi_header_end   // VirtualSize
+       .long   efi_header_end - _head  // VirtualAddress
+       .long   _edata - efi_header_end // SizeOfRawData
+       .long   efi_header_end - _head  // PointerToRawData
 
        .long   0               // PointerToRelocations (0 for executables)
        .long   0               // PointerToLineNumbers (0 for executables)
@@ -198,15 +196,18 @@ section_table:
        .long   0xe0500020      // Characteristics (section flags)
 
        /*
-        * EFI will load stext onwards at the 4k section alignment
+        * EFI will load .text onwards at the 4k section alignment
         * described in the PE/COFF header. To ensure that instruction
         * sequences using an adrp and a :lo12: immediate will function
-        * correctly at this alignment, we must ensure that stext is
+        * correctly at this alignment, we must ensure that .text is
         * placed at a 4k boundary in the Image to begin with.
         */
        .align 12
+efi_header_end:
 #endif
 
+       __INIT
+
 ENTRY(stext)
        bl      preserve_boot_args
        bl      el2_setup                       // Drop to EL1, w20=cpu_boot_mode
@@ -221,12 +222,12 @@ ENTRY(stext)
         * the TCR will have been set.
         */
        ldr     x27, 0f                         // address to jump to after
-                                               // MMU has been enabled
+       neg     x27, x27                        // MMU has been enabled
        adr_l   lr, __enable_mmu                // return (PIC) address
        b       __cpu_setup                     // initialise processor
 ENDPROC(stext)
        .align  3
-0:     .quad   __mmap_switched - (_head - TEXT_OFFSET) + KIMAGE_VADDR
+0:     .quad   (_text - TEXT_OFFSET) - __mmap_switched - KIMAGE_VADDR
 
 /*
  * Preserve the arguments passed by the bootloader in x0 .. x3
@@ -395,7 +396,7 @@ __create_page_tables:
        ldr     x5, =KIMAGE_VADDR
        add     x5, x5, x23                     // add KASLR displacement
        create_pgd_entry x0, x5, x3, x6
-       ldr     w6, kernel_img_size
+       ldr     w6, =kernel_img_size
        add     x6, x6, x5
        mov     x3, x24                         // phys offset
        create_block_map x0, x7, x3, x5, x6
@@ -412,9 +413,6 @@ __create_page_tables:
 
        ret     x28
 ENDPROC(__create_page_tables)
-
-kernel_img_size:
-       .long   _end - (_head - TEXT_OFFSET)
        .ltorg
 
 /*

diff --git a/arch/arm64/kernel/image.h b/arch/arm64/kernel/image.h
index db1bf57948f175a0fd3a9847897889ed5169c1e0..5ff892f40a0a8faeaa11f54e0796a97b631c219b 100644 (file)
--- a/arch/arm64/kernel/image.h
+++ b/arch/arm64/kernel/image.h
@@ -71,8 +71,12 @@
        DEFINE_IMAGE_LE64(_kernel_offset_le, TEXT_OFFSET);      \
        DEFINE_IMAGE_LE64(_kernel_flags_le, __HEAD_FLAGS);
 
+kernel_img_size = _end - (_text - TEXT_OFFSET);
+
 #ifdef CONFIG_EFI
 
+__efistub_stext_offset = stext - _text;
+
 /*
  * Prevent the symbol aliases below from being emitted into the kallsyms
  * table, by forcing them to be absolute symbols (which are conveniently