mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-07-18 17:18:01 +09:00
83d290c56f
When U-Boot started using SPDX tags we were among the early adopters and there weren't a lot of other examples to borrow from. So we picked the area of the file that usually had a full license text and replaced it with an appropriate SPDX-License-Identifier: entry. Since then, the Linux Kernel has adopted SPDX tags and they place it as the very first line in a file (except where shebangs are used, then it's second line) and with slightly different comment styles than us. In part due to community overlap, in part due to better tag visibility and in part for other minor reasons, switch over to that style. This commit changes all instances where we have a single declared license in the tag as both the before and after are identical in tag contents. There's also a few places where I found we did not have a tag and have introduced one. Signed-off-by: Tom Rini <trini@konsulko.com>
83 lines
2.6 KiB
C
83 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2017, Bin Meng <bmeng.cn@gmail.com>
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*/
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#include <common.h>
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#include <asm/acpi_s3.h>
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#include <asm/acpi_table.h>
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#include <asm/post.h>
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#include <linux/linkage.h>
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DECLARE_GLOBAL_DATA_PTR;
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static void asmlinkage (*acpi_do_wakeup)(void *vector) = (void *)WAKEUP_BASE;
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static void acpi_jump_to_wakeup(void *vector)
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{
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/* Copy wakeup trampoline in place */
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memcpy((void *)WAKEUP_BASE, __wakeup, __wakeup_size);
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printf("Jumping to OS waking vector %p\n", vector);
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acpi_do_wakeup(vector);
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}
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void acpi_resume(struct acpi_fadt *fadt)
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{
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void *wake_vec;
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/* Turn on ACPI mode for S3 */
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enter_acpi_mode(fadt->pm1a_cnt_blk);
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wake_vec = acpi_find_wakeup_vector(fadt);
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/*
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* Restore the memory content starting from address 0x1000 which is
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* used for the real mode interrupt handler stubs.
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*/
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memcpy((void *)0x1000, (const void *)gd->arch.backup_mem,
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S3_RESERVE_SIZE);
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post_code(POST_OS_RESUME);
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acpi_jump_to_wakeup(wake_vec);
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}
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int acpi_s3_reserve(void)
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{
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/* adjust stack pointer for ACPI S3 resume backup memory */
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gd->start_addr_sp -= S3_RESERVE_SIZE;
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gd->arch.backup_mem = gd->start_addr_sp;
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gd->start_addr_sp &= ~0xf;
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/*
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* U-Boot sets up the real mode interrupt handler stubs starting from
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* address 0x1000. In most cases, the first 640K (0x00000 - 0x9ffff)
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* system memory is reported as system RAM in E820 table to the OS.
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* (see install_e820_map() implementation for each platform). So OS
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* can use these memories whatever it wants.
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*
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* If U-Boot is in an S3 resume path, care must be taken not to corrupt
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* these memorie otherwise OS data gets lost. Testing shows that, on
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* Microsoft Windows 10 on Intel Baytrail its wake up vector happens to
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* be installed at the same address 0x1000. While on Linux its wake up
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* vector does not overlap this memory range, but after resume kernel
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* checks low memory range per config option CONFIG_X86_RESERVE_LOW
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* which is 64K by default to see whether a memory corruption occurs
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* during the suspend/resume (it's harmless, but warnings are shown
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* in the kernel dmesg logs).
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*
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* We cannot simply mark the these memory as reserved in E820 table
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* because such configuration makes GRUB complain: unable to allocate
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* real mode page. Hence we choose to back up these memories to the
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* place where we reserved on our stack for our S3 resume work.
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* Before jumping to OS wake up vector, we need restore the original
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* content there (see acpi_resume() above).
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*/
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if (gd->arch.prev_sleep_state == ACPI_S3)
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memcpy((void *)gd->arch.backup_mem, (const void *)0x1000,
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S3_RESERVE_SIZE);
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return 0;
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}
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