1d7071743SAtish Patra // SPDX-License-Identifier: GPL-2.0 2d7071743SAtish Patra /* 3d7071743SAtish Patra * Copyright (C) 2020 Western Digital Corporation or its affiliates. 4d7071743SAtish Patra */ 5d7071743SAtish Patra 6d7071743SAtish Patra #include <linux/efi.h> 7d7071743SAtish Patra #include <linux/libfdt.h> 8d7071743SAtish Patra 9d7071743SAtish Patra #include <asm/efi.h> 10d7071743SAtish Patra #include <asm/sections.h> 11d7071743SAtish Patra 12d7071743SAtish Patra #include "efistub.h" 13d7071743SAtish Patra 14d7071743SAtish Patra /* 15d7071743SAtish Patra * RISC-V requires the kernel image to placed 2 MB aligned base for 64 bit and 16d7071743SAtish Patra * 4MB for 32 bit. 17d7071743SAtish Patra */ 18d7071743SAtish Patra #ifdef CONFIG_64BIT 19d7071743SAtish Patra #define MIN_KIMG_ALIGN SZ_2M 20d7071743SAtish Patra #else 21d7071743SAtish Patra #define MIN_KIMG_ALIGN SZ_4M 22d7071743SAtish Patra #endif 23d7071743SAtish Patra 24d7071743SAtish Patra typedef void __noreturn (*jump_kernel_func)(unsigned int, unsigned long); 25d7071743SAtish Patra 26d7071743SAtish Patra static u32 hartid; 27d7071743SAtish Patra 28dcf0c838SSunil V L static int get_boot_hartid_from_fdt(void) 29d7071743SAtish Patra { 30d7071743SAtish Patra const void *fdt; 31d7071743SAtish Patra int chosen_node, len; 32d7071743SAtish Patra const fdt32_t *prop; 33d7071743SAtish Patra 34d7071743SAtish Patra fdt = get_efi_config_table(DEVICE_TREE_GUID); 35d7071743SAtish Patra if (!fdt) 36dcf0c838SSunil V L return -EINVAL; 37d7071743SAtish Patra 38d7071743SAtish Patra chosen_node = fdt_path_offset(fdt, "/chosen"); 39d7071743SAtish Patra if (chosen_node < 0) 40dcf0c838SSunil V L return -EINVAL; 41d7071743SAtish Patra 42d7071743SAtish Patra prop = fdt_getprop((void *)fdt, chosen_node, "boot-hartid", &len); 43d7071743SAtish Patra if (!prop || len != sizeof(u32)) 44dcf0c838SSunil V L return -EINVAL; 45d7071743SAtish Patra 46dcf0c838SSunil V L hartid = fdt32_to_cpu(*prop); 47dcf0c838SSunil V L return 0; 48d7071743SAtish Patra } 49d7071743SAtish Patra 50d7071743SAtish Patra efi_status_t check_platform_features(void) 51d7071743SAtish Patra { 52dcf0c838SSunil V L int ret; 53dcf0c838SSunil V L 54dcf0c838SSunil V L ret = get_boot_hartid_from_fdt(); 55dcf0c838SSunil V L if (ret) { 56d7071743SAtish Patra efi_err("/chosen/boot-hartid missing or invalid!\n"); 57d7071743SAtish Patra return EFI_UNSUPPORTED; 58d7071743SAtish Patra } 59d7071743SAtish Patra return EFI_SUCCESS; 60d7071743SAtish Patra } 61d7071743SAtish Patra 62d7071743SAtish Patra void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt, 63d7071743SAtish Patra unsigned long fdt_size) 64d7071743SAtish Patra { 65d7071743SAtish Patra unsigned long stext_offset = _start_kernel - _start; 66d7071743SAtish Patra unsigned long kernel_entry = entrypoint + stext_offset; 67d7071743SAtish Patra jump_kernel_func jump_kernel = (jump_kernel_func)kernel_entry; 68d7071743SAtish Patra 69d7071743SAtish Patra /* 70d7071743SAtish Patra * Jump to real kernel here with following constraints. 71d7071743SAtish Patra * 1. MMU should be disabled. 72d7071743SAtish Patra * 2. a0 should contain hartid 73d7071743SAtish Patra * 3. a1 should DT address 74d7071743SAtish Patra */ 75d7071743SAtish Patra csr_write(CSR_SATP, 0); 76d7071743SAtish Patra jump_kernel(hartid, fdt); 77d7071743SAtish Patra } 78d7071743SAtish Patra 79d7071743SAtish Patra efi_status_t handle_kernel_image(unsigned long *image_addr, 80d7071743SAtish Patra unsigned long *image_size, 81d7071743SAtish Patra unsigned long *reserve_addr, 82d7071743SAtish Patra unsigned long *reserve_size, 83*416a9f84SArd Biesheuvel efi_loaded_image_t *image, 84*416a9f84SArd Biesheuvel efi_handle_t image_handle) 85d7071743SAtish Patra { 86d7071743SAtish Patra unsigned long kernel_size = 0; 87d7071743SAtish Patra unsigned long preferred_addr; 88d7071743SAtish Patra efi_status_t status; 89d7071743SAtish Patra 90d7071743SAtish Patra kernel_size = _edata - _start; 91d7071743SAtish Patra *image_addr = (unsigned long)_start; 92d7071743SAtish Patra *image_size = kernel_size + (_end - _edata); 93d7071743SAtish Patra 94d7071743SAtish Patra /* 95d7071743SAtish Patra * RISC-V kernel maps PAGE_OFFSET virtual address to the same physical 96d7071743SAtish Patra * address where kernel is booted. That's why kernel should boot from 97d7071743SAtish Patra * as low as possible to avoid wastage of memory. Currently, dram_base 98d7071743SAtish Patra * is occupied by the firmware. So the preferred address for kernel to 99d7071743SAtish Patra * boot is next aligned address. If preferred address is not available, 100d7071743SAtish Patra * relocate_kernel will fall back to efi_low_alloc_above to allocate 101d7071743SAtish Patra * lowest possible memory region as long as the address and size meets 102d7071743SAtish Patra * the alignment constraints. 103d7071743SAtish Patra */ 104d7071743SAtish Patra preferred_addr = MIN_KIMG_ALIGN; 105d7071743SAtish Patra status = efi_relocate_kernel(image_addr, kernel_size, *image_size, 106d7071743SAtish Patra preferred_addr, MIN_KIMG_ALIGN, 0x0); 107d7071743SAtish Patra 108d7071743SAtish Patra if (status != EFI_SUCCESS) { 109d7071743SAtish Patra efi_err("Failed to relocate kernel\n"); 110d7071743SAtish Patra *image_size = 0; 111d7071743SAtish Patra } 112d7071743SAtish Patra return status; 113d7071743SAtish Patra } 114