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// SPDX-License-Identifier: GPL-2.0-only
/*
* powerpc code to implement the kexec_file_load syscall
*
* Copyright (C) 2004 Adam Litke (agl@us.ibm.com)
* Copyright (C) 2004 IBM Corp.
* Copyright (C) 2004,2005 Milton D Miller II, IBM Corporation
* Copyright (C) 2005 R Sharada (sharada@in.ibm.com)
* Copyright (C) 2006 Mohan Kumar M (mohan@in.ibm.com)
* Copyright (C) 2016 IBM Corporation
*
* Based on kexec-tools' kexec-elf-ppc64.c, fs2dt.c.
* Heavily modified for the kernel by
* Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
*/
#include <linux/slab.h>
#include <linux/kexec.h>
#include <linux/of_fdt.h>
#include <linux/libfdt.h>
#include <asm/setup.h>
#define SLAVE_CODE_SIZE 256 /* First 0x100 bytes */
/**
* setup_kdump_cmdline - Prepend "elfcorehdr=<addr> " to command line
* of kdump kernel for exporting the core.
* @image: Kexec image
* @cmdline: Command line parameters to update.
* @cmdline_len: Length of the cmdline parameters.
*
* kdump segment must be setup before calling this function.
*
* Returns new cmdline buffer for kdump kernel on success, NULL otherwise.
*/
char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
unsigned long cmdline_len)
{
int elfcorehdr_strlen;
char *cmdline_ptr;
cmdline_ptr = kzalloc(COMMAND_LINE_SIZE, GFP_KERNEL);
if (!cmdline_ptr)
return NULL;
elfcorehdr_strlen = sprintf(cmdline_ptr, "elfcorehdr=0x%lx ",
image->elf_load_addr);
if (elfcorehdr_strlen + cmdline_len > COMMAND_LINE_SIZE) {
pr_err("Appending elfcorehdr=<addr> exceeds cmdline size\n");
kfree(cmdline_ptr);
return NULL;
}
memcpy(cmdline_ptr + elfcorehdr_strlen, cmdline, cmdline_len);
// Ensure it's nul terminated
cmdline_ptr[COMMAND_LINE_SIZE - 1] = '\0';
return cmdline_ptr;
}
/**
* setup_purgatory - initialize the purgatory's global variables
* @image: kexec image.
* @slave_code: Slave code for the purgatory.
* @fdt: Flattened device tree for the next kernel.
* @kernel_load_addr: Address where the kernel is loaded.
* @fdt_load_addr: Address where the flattened device tree is loaded.
*
* Return: 0 on success, or negative errno on error.
*/
int setup_purgatory(struct kimage *image, const void *slave_code,
const void *fdt, unsigned long kernel_load_addr,
unsigned long fdt_load_addr)
{
unsigned int *slave_code_buf, master_entry;
int ret;
slave_code_buf = kmalloc(SLAVE_CODE_SIZE, GFP_KERNEL);
if (!slave_code_buf)
return -ENOMEM;
/* Get the slave code from the new kernel and put it in purgatory. */
ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
slave_code_buf, SLAVE_CODE_SIZE,
true);
if (ret) {
kfree(slave_code_buf);
return ret;
}
master_entry = slave_code_buf[0];
memcpy(slave_code_buf, slave_code, SLAVE_CODE_SIZE);
slave_code_buf[0] = master_entry;
ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
slave_code_buf, SLAVE_CODE_SIZE,
false);
kfree(slave_code_buf);
ret = kexec_purgatory_get_set_symbol(image, "kernel", &kernel_load_addr,
sizeof(kernel_load_addr), false);
if (ret)
return ret;
ret = kexec_purgatory_get_set_symbol(image, "dt_offset", &fdt_load_addr,
sizeof(fdt_load_addr), false);
if (ret)
return ret;
return 0;
}
/**
* delete_fdt_mem_rsv - delete memory reservation with given address and size
*
* Return: 0 on success, or negative errno on error.
*/
int delete_fdt_mem_rsv(void *fdt, unsigned long start, unsigned long size)
{
int i, ret, num_rsvs = fdt_num_mem_rsv(fdt);
for (i = 0; i < num_rsvs; i++) {
uint64_t rsv_start, rsv_size;
ret = fdt_get_mem_rsv(fdt, i, &rsv_start, &rsv_size);
if (ret) {
pr_err("Malformed device tree.\n");
return -EINVAL;
}
if (rsv_start == start && rsv_size == size) {
ret = fdt_del_mem_rsv(fdt, i);
if (ret) {
pr_err("Error deleting device tree reservation.\n");
return -EINVAL;
}
return 0;
}
}
return -ENOENT;
}
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