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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020 Western Digital Corporation or its affiliates.
*/
#include <linux/efi.h>
#include <linux/libfdt.h>
#include <asm/efi.h>
#include <asm/sections.h>
#include <asm/unaligned.h>
#include "efistub.h"
/*
* RISC-V requires the kernel image to placed 2 MB aligned base for 64 bit and
* 4MB for 32 bit.
*/
#ifdef CONFIG_64BIT
#define MIN_KIMG_ALIGN SZ_2M
#else
#define MIN_KIMG_ALIGN SZ_4M
#endif
typedef void __noreturn (*jump_kernel_func)(unsigned long, unsigned long);
static unsigned long hartid;
static int get_boot_hartid_from_fdt(void)
{
const void *fdt;
int chosen_node, len;
const void *prop;
fdt = get_efi_config_table(DEVICE_TREE_GUID);
if (!fdt)
return -EINVAL;
chosen_node = fdt_path_offset(fdt, "/chosen");
if (chosen_node < 0)
return -EINVAL;
prop = fdt_getprop((void *)fdt, chosen_node, "boot-hartid", &len);
if (!prop)
return -EINVAL;
if (len == sizeof(u32))
hartid = (unsigned long) fdt32_to_cpu(*(fdt32_t *)prop);
else if (len == sizeof(u64))
hartid = (unsigned long) fdt64_to_cpu(__get_unaligned_t(fdt64_t, prop));
else
return -EINVAL;
return 0;
}
static efi_status_t get_boot_hartid_from_efi(void)
{
efi_guid_t boot_protocol_guid = RISCV_EFI_BOOT_PROTOCOL_GUID;
struct riscv_efi_boot_protocol *boot_protocol;
efi_status_t status;
status = efi_bs_call(locate_protocol, &boot_protocol_guid, NULL,
(void **)&boot_protocol);
if (status != EFI_SUCCESS)
return status;
return efi_call_proto(boot_protocol, get_boot_hartid, &hartid);
}
efi_status_t check_platform_features(void)
{
efi_status_t status;
int ret;
status = get_boot_hartid_from_efi();
if (status != EFI_SUCCESS) {
ret = get_boot_hartid_from_fdt();
if (ret) {
efi_err("Failed to get boot hartid!\n");
return EFI_UNSUPPORTED;
}
}
return EFI_SUCCESS;
}
void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt,
unsigned long fdt_size)
{
unsigned long stext_offset = _start_kernel - _start;
unsigned long kernel_entry = entrypoint + stext_offset;
jump_kernel_func jump_kernel = (jump_kernel_func)kernel_entry;
/*
* Jump to real kernel here with following constraints.
* 1. MMU should be disabled.
* 2. a0 should contain hartid
* 3. a1 should DT address
*/
csr_write(CSR_SATP, 0);
jump_kernel(hartid, fdt);
}
efi_status_t handle_kernel_image(unsigned long *image_addr,
unsigned long *image_size,
unsigned long *reserve_addr,
unsigned long *reserve_size,
efi_loaded_image_t *image,
efi_handle_t image_handle)
{
unsigned long kernel_size = 0;
unsigned long preferred_addr;
efi_status_t status;
kernel_size = _edata - _start;
*image_addr = (unsigned long)_start;
*image_size = kernel_size + (_end - _edata);
/*
* RISC-V kernel maps PAGE_OFFSET virtual address to the same physical
* address where kernel is booted. That's why kernel should boot from
* as low as possible to avoid wastage of memory. Currently, dram_base
* is occupied by the firmware. So the preferred address for kernel to
* boot is next aligned address. If preferred address is not available,
* relocate_kernel will fall back to efi_low_alloc_above to allocate
* lowest possible memory region as long as the address and size meets
* the alignment constraints.
*/
preferred_addr = MIN_KIMG_ALIGN;
status = efi_relocate_kernel(image_addr, kernel_size, *image_size,
preferred_addr, MIN_KIMG_ALIGN, 0x0);
if (status != EFI_SUCCESS) {
efi_err("Failed to relocate kernel\n");
*image_size = 0;
}
return status;
}
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