| Olivier Deprez | 157378f | 2022-04-04 15:47:50 +0200 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Copyright (C) 2020 Western Digital Corporation or its affiliates. |
| 4 | */ |
| 5 | |
| 6 | #include <linux/efi.h> |
| 7 | #include <linux/libfdt.h> |
| 8 | |
| 9 | #include <asm/efi.h> |
| 10 | #include <asm/sections.h> |
| 11 | |
| 12 | #include "efistub.h" |
| 13 | |
| 14 | /* |
| 15 | * RISC-V requires the kernel image to placed 2 MB aligned base for 64 bit and |
| 16 | * 4MB for 32 bit. |
| 17 | */ |
| 18 | #ifdef CONFIG_64BIT |
| 19 | #define MIN_KIMG_ALIGN SZ_2M |
| 20 | #else |
| 21 | #define MIN_KIMG_ALIGN SZ_4M |
| 22 | #endif |
| 23 | |
| 24 | typedef void __noreturn (*jump_kernel_func)(unsigned int, unsigned long); |
| 25 | |
| 26 | static u32 hartid; |
| 27 | |
| 28 | static int get_boot_hartid_from_fdt(void) |
| 29 | { |
| 30 | const void *fdt; |
| 31 | int chosen_node, len; |
| 32 | const fdt32_t *prop; |
| 33 | |
| 34 | fdt = get_efi_config_table(DEVICE_TREE_GUID); |
| 35 | if (!fdt) |
| 36 | return -EINVAL; |
| 37 | |
| 38 | chosen_node = fdt_path_offset(fdt, "/chosen"); |
| 39 | if (chosen_node < 0) |
| 40 | return -EINVAL; |
| 41 | |
| 42 | prop = fdt_getprop((void *)fdt, chosen_node, "boot-hartid", &len); |
| 43 | if (!prop || len != sizeof(u32)) |
| 44 | return -EINVAL; |
| 45 | |
| 46 | hartid = fdt32_to_cpu(*prop); |
| 47 | return 0; |
| 48 | } |
| 49 | |
| 50 | efi_status_t check_platform_features(void) |
| 51 | { |
| 52 | int ret; |
| 53 | |
| 54 | ret = get_boot_hartid_from_fdt(); |
| 55 | if (ret) { |
| 56 | efi_err("/chosen/boot-hartid missing or invalid!\n"); |
| 57 | return EFI_UNSUPPORTED; |
| 58 | } |
| 59 | return EFI_SUCCESS; |
| 60 | } |
| 61 | |
| 62 | void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt, |
| 63 | unsigned long fdt_size) |
| 64 | { |
| 65 | unsigned long stext_offset = _start_kernel - _start; |
| 66 | unsigned long kernel_entry = entrypoint + stext_offset; |
| 67 | jump_kernel_func jump_kernel = (jump_kernel_func)kernel_entry; |
| 68 | |
| 69 | /* |
| 70 | * Jump to real kernel here with following constraints. |
| 71 | * 1. MMU should be disabled. |
| 72 | * 2. a0 should contain hartid |
| 73 | * 3. a1 should DT address |
| 74 | */ |
| 75 | csr_write(CSR_SATP, 0); |
| 76 | jump_kernel(hartid, fdt); |
| 77 | } |
| 78 | |
| 79 | efi_status_t handle_kernel_image(unsigned long *image_addr, |
| 80 | unsigned long *image_size, |
| 81 | unsigned long *reserve_addr, |
| 82 | unsigned long *reserve_size, |
| 83 | efi_loaded_image_t *image) |
| 84 | { |
| 85 | unsigned long kernel_size = 0; |
| 86 | unsigned long preferred_addr; |
| 87 | efi_status_t status; |
| 88 | |
| 89 | kernel_size = _edata - _start; |
| 90 | *image_addr = (unsigned long)_start; |
| 91 | *image_size = kernel_size + (_end - _edata); |
| 92 | |
| 93 | /* |
| 94 | * RISC-V kernel maps PAGE_OFFSET virtual address to the same physical |
| 95 | * address where kernel is booted. That's why kernel should boot from |
| 96 | * as low as possible to avoid wastage of memory. Currently, dram_base |
| 97 | * is occupied by the firmware. So the preferred address for kernel to |
| 98 | * boot is next aligned address. If preferred address is not available, |
| 99 | * relocate_kernel will fall back to efi_low_alloc_above to allocate |
| 100 | * lowest possible memory region as long as the address and size meets |
| 101 | * the alignment constraints. |
| 102 | */ |
| 103 | preferred_addr = MIN_KIMG_ALIGN; |
| 104 | status = efi_relocate_kernel(image_addr, kernel_size, *image_size, |
| 105 | preferred_addr, MIN_KIMG_ALIGN, 0x0); |
| 106 | |
| 107 | if (status != EFI_SUCCESS) { |
| 108 | efi_err("Failed to relocate kernel\n"); |
| 109 | *image_size = 0; |
| 110 | } |
| 111 | return status; |
| 112 | } |