[PATCH RFT] ARM64: cpu: support 64-bit stack top in ENTRY_FUNCTION_WITHSTACK

[Ahmad Fatoum]

On 01.06.23 10:33, Lior Weintraub wrote:
> Hi Ahmad,
> Thanks for the patch.
> I have checked it and can verify it is working correctly.

Great! I am replying with:

Tested-by: Lior Weintraub <liorw at pliops.com>

So the scripts pulling patches from the mailing list will automatically
collect the tag and fold it into the commit message.

Cheers,
Ahmad


> Cheers,
> Lior.
> 
>> -----Original Message-----
>> From: Ahmad Fatoum <a.fatoum at pengutronix.de>
>> Sent: Wednesday, May 31, 2023 8:52 PM
>> To: barebox at lists.infradead.org
>> Cc: Lior Weintraub <liorw at pliops.com>; Ahmad Fatoum
>> <a.fatoum at pengutronix.de>
>> Subject: [PATCH RFT] ARM64: cpu: support 64-bit stack top in
>> ENTRY_FUNCTION_WITHSTACK
>>
>> CAUTION: External Sender
>>
>> ENTRY_FUNCTION_WITHSTACK was written with the naive assumption that
>> there will always be some memory in the first 32-bit of the address
>> space to be used as early stack. There are SoCs out there though with
>> sole on-chip SRAM > 4G. Accommodate this by accepting full 64-bit stack
>> pointers in ENTRY_FUNCTION_WITHSTACK.
>>
>> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
>> ---
>>  arch/arm/cpu/head_64.S             | 2 +-
>>  arch/arm/include/asm/barebox-arm.h | 2 +-
>>  arch/arm/lib/pbl.lds.S             | 7 ++++---
>>  include/asm-generic/pointer.h      | 2 ++
>>  4 files changed, 8 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/arm/cpu/head_64.S b/arch/arm/cpu/head_64.S
>> index 398c4d3471e0..546efc263a06 100644
>> --- a/arch/arm/cpu/head_64.S
>> +++ b/arch/arm/cpu/head_64.S
>> @@ -11,7 +11,7 @@
>>  ENTRY(__barebox_arm64_head)
>>         nop
>>         adr x9, __pbl_board_stack_top
>> -       ldr w9, [x9]
>> +       ldr x9, [x9]
>>         cbz x9, 1f
>>         mov sp, x9
>>  1:
>> diff --git a/arch/arm/include/asm/barebox-arm.h
>> b/arch/arm/include/asm/barebox-arm.h
>> index eb31ca278821..aceb7fdf74f8 100644
>> --- a/arch/arm/include/asm/barebox-arm.h
>> +++ b/arch/arm/include/asm/barebox-arm.h
>> @@ -158,7 +158,7 @@ void __barebox_arm64_head(ulong x0, ulong x1,
>> ulong x2);
>>                                 (ulong r0, ulong r1, ulong r2)          \
>>                 {                                                       \
>>                         static __section(.pbl_board_stack_top_##name)   \
>> -                               const u32 __stack_top = (stack_top);    \
>> +                               const ulong __stack_top = (stack_top);  \
>>                         __keep_symbolref(__barebox_arm64_head);         \
>>                         __keep_symbolref(__stack_top);                  \
>>                         __##name(r0, r1, r2);                           \
>> diff --git a/arch/arm/lib/pbl.lds.S b/arch/arm/lib/pbl.lds.S
>> index 114ec7bc8195..2b4b1d6a9513 100644
>> --- a/arch/arm/lib/pbl.lds.S
>> +++ b/arch/arm/lib/pbl.lds.S
>> @@ -4,6 +4,7 @@
>>  #include <linux/sizes.h>
>>  #include <asm/barebox.lds.h>
>>  #include <asm-generic/memory_layout.h>
>> +#include <asm-generic/pointer.h>
>>
>>  #ifdef CONFIG_PBL_RELOCATABLE
>>  #define BASE   0x0
>> @@ -44,14 +45,14 @@ SECTIONS
>>         . = ALIGN(4);
>>         .rodata : { *(.rodata*) }
>>
>> -       . = ALIGN(4);
>> +       . = ALIGN(ASM_SZPTR);
>>         __pbl_board_stack_top = .;
>>         .rodata.pbl_board_stack_top : {
>>                 *(.pbl_board_stack_top_*)
>>                 /* Dummy for when BootROM sets up usable stack */
>> -               LONG(0x00000000);
>> +               ASM_LD_PTR(0x00000000)
>>         }
>> -       ASSERT(. - __pbl_board_stack_top <= 8, "Only One PBL per Image
>> allowed")
>> +       ASSERT(. - __pbl_board_stack_top <= 2 * ASM_SZPTR, "Only One PBL per
>> Image allowed")
>>
>>         .barebox_imd : { BAREBOX_IMD }
>>
>> diff --git a/include/asm-generic/pointer.h b/include/asm-generic/pointer.h
>> index 8b9600b02939..89817ce59ebc 100644
>> --- a/include/asm-generic/pointer.h
>> +++ b/include/asm-generic/pointer.h
>> @@ -8,6 +8,7 @@
>>  #define ASM_PTR                .quad
>>  #define ASM_SZPTR      8
>>  #define ASM_LGPTR      3
>> +#define ASM_LD_PTR(x)  QUAD(x)
>>  #else
>>  #define ASM_PTR                ".quad"
>>  #define ASM_SZPTR      "8"
>> @@ -18,6 +19,7 @@
>>  #define ASM_PTR                .word
>>  #define ASM_SZPTR      4
>>  #define ASM_LGPTR      2
>> +#define ASM_LD_PTR(x)  LONG(x)
>>  #else
>>  #define ASM_PTR                ".word"
>>  #define ASM_SZPTR      "4"
>> --
>> 2.39.2
> 
> 
> 

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