Tom Rini | 10e4779 | 2018-05-06 17:58:06 -0400 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
Bin Meng | 710d215 | 2017-04-21 07:24:37 -0700 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (C) 2017, Bin Meng <bmeng.cn@gmail.com> |
Bin Meng | 710d215 | 2017-04-21 07:24:37 -0700 | [diff] [blame] | 4 | */ |
| 5 | |
| 6 | #include <common.h> |
Simon Glass | 5046109 | 2020-04-08 16:57:35 -0600 | [diff] [blame] | 7 | #include <acpi/acpi_s3.h> |
Simon Glass | 858fed1 | 2020-04-08 16:57:36 -0600 | [diff] [blame] | 8 | #include <acpi/acpi_table.h> |
Bin Meng | ac63025 | 2018-07-18 21:42:15 -0700 | [diff] [blame] | 9 | #include <asm/acpi.h> |
Bin Meng | 710d215 | 2017-04-21 07:24:37 -0700 | [diff] [blame] | 10 | #include <asm/post.h> |
Bin Meng | e218c8d | 2017-08-08 04:35:07 -0700 | [diff] [blame] | 11 | #include <linux/linkage.h> |
Bin Meng | 710d215 | 2017-04-21 07:24:37 -0700 | [diff] [blame] | 12 | |
Bin Meng | 353f5cb | 2017-04-21 07:24:47 -0700 | [diff] [blame] | 13 | DECLARE_GLOBAL_DATA_PTR; |
| 14 | |
Bin Meng | 710d215 | 2017-04-21 07:24:37 -0700 | [diff] [blame] | 15 | static void asmlinkage (*acpi_do_wakeup)(void *vector) = (void *)WAKEUP_BASE; |
| 16 | |
| 17 | static void acpi_jump_to_wakeup(void *vector) |
| 18 | { |
| 19 | /* Copy wakeup trampoline in place */ |
| 20 | memcpy((void *)WAKEUP_BASE, __wakeup, __wakeup_size); |
| 21 | |
| 22 | printf("Jumping to OS waking vector %p\n", vector); |
| 23 | acpi_do_wakeup(vector); |
| 24 | } |
| 25 | |
Bin Meng | 280aebe | 2017-04-21 07:24:44 -0700 | [diff] [blame] | 26 | void acpi_resume(struct acpi_fadt *fadt) |
Bin Meng | 710d215 | 2017-04-21 07:24:37 -0700 | [diff] [blame] | 27 | { |
Bin Meng | 280aebe | 2017-04-21 07:24:44 -0700 | [diff] [blame] | 28 | void *wake_vec; |
| 29 | |
Bin Meng | 07d46e6 | 2017-04-21 07:24:45 -0700 | [diff] [blame] | 30 | /* Turn on ACPI mode for S3 */ |
| 31 | enter_acpi_mode(fadt->pm1a_cnt_blk); |
| 32 | |
Bin Meng | 280aebe | 2017-04-21 07:24:44 -0700 | [diff] [blame] | 33 | wake_vec = acpi_find_wakeup_vector(fadt); |
| 34 | |
Bin Meng | 353f5cb | 2017-04-21 07:24:47 -0700 | [diff] [blame] | 35 | /* |
| 36 | * Restore the memory content starting from address 0x1000 which is |
| 37 | * used for the real mode interrupt handler stubs. |
| 38 | */ |
| 39 | memcpy((void *)0x1000, (const void *)gd->arch.backup_mem, |
| 40 | S3_RESERVE_SIZE); |
| 41 | |
Bin Meng | 710d215 | 2017-04-21 07:24:37 -0700 | [diff] [blame] | 42 | post_code(POST_OS_RESUME); |
| 43 | acpi_jump_to_wakeup(wake_vec); |
| 44 | } |
Bin Meng | 353f5cb | 2017-04-21 07:24:47 -0700 | [diff] [blame] | 45 | |
| 46 | int acpi_s3_reserve(void) |
| 47 | { |
| 48 | /* adjust stack pointer for ACPI S3 resume backup memory */ |
| 49 | gd->start_addr_sp -= S3_RESERVE_SIZE; |
| 50 | gd->arch.backup_mem = gd->start_addr_sp; |
| 51 | |
| 52 | gd->start_addr_sp &= ~0xf; |
| 53 | |
| 54 | /* |
| 55 | * U-Boot sets up the real mode interrupt handler stubs starting from |
| 56 | * address 0x1000. In most cases, the first 640K (0x00000 - 0x9ffff) |
| 57 | * system memory is reported as system RAM in E820 table to the OS. |
| 58 | * (see install_e820_map() implementation for each platform). So OS |
| 59 | * can use these memories whatever it wants. |
| 60 | * |
| 61 | * If U-Boot is in an S3 resume path, care must be taken not to corrupt |
| 62 | * these memorie otherwise OS data gets lost. Testing shows that, on |
| 63 | * Microsoft Windows 10 on Intel Baytrail its wake up vector happens to |
| 64 | * be installed at the same address 0x1000. While on Linux its wake up |
| 65 | * vector does not overlap this memory range, but after resume kernel |
| 66 | * checks low memory range per config option CONFIG_X86_RESERVE_LOW |
| 67 | * which is 64K by default to see whether a memory corruption occurs |
| 68 | * during the suspend/resume (it's harmless, but warnings are shown |
| 69 | * in the kernel dmesg logs). |
| 70 | * |
| 71 | * We cannot simply mark the these memory as reserved in E820 table |
| 72 | * because such configuration makes GRUB complain: unable to allocate |
| 73 | * real mode page. Hence we choose to back up these memories to the |
| 74 | * place where we reserved on our stack for our S3 resume work. |
| 75 | * Before jumping to OS wake up vector, we need restore the original |
| 76 | * content there (see acpi_resume() above). |
| 77 | */ |
| 78 | if (gd->arch.prev_sleep_state == ACPI_S3) |
| 79 | memcpy((void *)gd->arch.backup_mem, (const void *)0x1000, |
| 80 | S3_RESERVE_SIZE); |
| 81 | |
| 82 | return 0; |
| 83 | } |