[U-Boot] [PATCH 11/22] x86: acpi: Resume OS if resume vector is found

[Bin Meng]

Hi Simon,

On Wed, Mar 22, 2017 at 4:06 AM, Simon Glass <sjg at chromium.org> wrote:
> Hi Bin,
>
> On 16 March 2017 at 08:26, Bin Meng <bmeng.cn at gmail.com> wrote:
>> In an S3 resume path, U-Boot does everything like a cold boot except
>> in the last_stage_init() it jumps to the OS resume vector.
>>
>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>> ---
>>
>>  arch/x86/cpu/cpu.c             |  8 ++++++++
>>  arch/x86/include/asm/acpi_s3.h | 10 ++++++++++
>>  arch/x86/lib/Makefile          |  1 +
>>  arch/x86/lib/acpi_s3.c         | 26 ++++++++++++++++++++++++++
>>  4 files changed, 45 insertions(+)
>>  create mode 100644 arch/x86/lib/acpi_s3.c
>
> Reviewed-by: Simon Glass <sjg at chromium.org>
>
>>
>> diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
>> index 9dde54c..afc8645 100644
>> --- a/arch/x86/cpu/cpu.c
>> +++ b/arch/x86/cpu/cpu.c
>> @@ -26,6 +26,7 @@
>>  #include <malloc.h>
>>  #include <syscon.h>
>>  #include <asm/acpi_s3.h>
>> +#include <asm/acpi_table.h>
>>  #include <asm/control_regs.h>
>>  #include <asm/coreboot_tables.h>
>>  #include <asm/cpu.h>
>> @@ -204,6 +205,13 @@ __weak void board_final_cleanup(void)
>>
>>  int last_stage_init(void)
>>  {
>> +#if CONFIG_HAVE_ACPI_RESUME
>> +       void *wake_vector = acpi_find_wakeup_vector();
>> +
>> +       if (wake_vector != NULL && gd->arch.prev_sleep_state == ACPI_S3)
>> +               acpi_resume(wake_vector);
>> +#endif
>> +
>>         write_tables();
>>
>>         board_final_cleanup();
>> diff --git a/arch/x86/include/asm/acpi_s3.h b/arch/x86/include/asm/acpi_s3.h
>> index f9d4739..5892a8b 100644
>> --- a/arch/x86/include/asm/acpi_s3.h
>> +++ b/arch/x86/include/asm/acpi_s3.h
>> @@ -100,6 +100,16 @@ enum acpi_sleep_state chipset_prev_sleep_state(void);
>>   */
>>  void chipset_clear_sleep_state(void);
>>
>> +/**
>> + * acpi_resume() - Do ACPI S3 resume
>> + *
>> + * This calls U-Boot wake up assembly stub and jumps to OS's wake up vector.
>> + *
>> + * @wake_vec:  OS wake up vector
>> + * @return:    Never returns
>> + */
>> +void acpi_resume(void *wake_vec);
>> +
>>  #endif /* __ASSEMBLY__ */
>>
>>  #endif /* __ASM_ACPI_S3_H__ */
>> diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
>> index 1c2c085..c61f931 100644
>> --- a/arch/x86/lib/Makefile
>> +++ b/arch/x86/lib/Makefile
>> @@ -35,6 +35,7 @@ obj-$(CONFIG_X86_RAMTEST) += ramtest.o
>>  obj-y  += sections.o
>>  obj-y += sfi.o
>>  obj-y  += string.o
>> +obj-$(CONFIG_HAVE_ACPI_RESUME) += acpi_s3.o
>>  ifndef CONFIG_QEMU
>>  obj-$(CONFIG_GENERATE_ACPI_TABLE) += acpi_table.o
>>  endif
>> diff --git a/arch/x86/lib/acpi_s3.c b/arch/x86/lib/acpi_s3.c
>> new file mode 100644
>> index 0000000..f679c06
>> --- /dev/null
>> +++ b/arch/x86/lib/acpi_s3.c
>> @@ -0,0 +1,26 @@
>> +/*
>> + * Copyright (C) 2017, Bin Meng <bmeng.cn at gmail.com>
>> + *
>> + * SPDX-License-Identifier:    GPL-2.0+
>> + */
>> +
>> +#include <common.h>
>> +#include <asm/acpi_s3.h>
>> +#include <asm/post.h>
>> +
>> +static void asmlinkage (*acpi_do_wakeup)(void *vector) = (void *)WAKEUP_BASE;
>> +
>> +static void acpi_jump_to_wakeup(void *vector)
>> +{
>> +       /* Copy wakeup trampoline in place */
>> +       memcpy((void *)WAKEUP_BASE, __wakeup, __wakeup_size);
>> +
>> +       printf("Jumping to OS waking vector %p\n", vector);
>
> Should this be debug()?
>

I wanted to explicitly print this to show that we are in S3 and
jumping to OS vector. Actually I was even thinking we should introduce
a log level for U-Boot, just like coreboot/linux.

Regards,
Bin