cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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machine_kexec.c (5447B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * machine_kexec.c - handle transition of Linux booting another kernel
      4 * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
      5 *
      6 * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
      7 * LANDISK/sh4 supported by kogiidena
      8 */
      9#include <linux/mm.h>
     10#include <linux/kexec.h>
     11#include <linux/delay.h>
     12#include <linux/reboot.h>
     13#include <linux/numa.h>
     14#include <linux/ftrace.h>
     15#include <linux/suspend.h>
     16#include <linux/memblock.h>
     17#include <asm/mmu_context.h>
     18#include <asm/io.h>
     19#include <asm/cacheflush.h>
     20#include <asm/sh_bios.h>
     21#include <asm/reboot.h>
     22
     23typedef void (*relocate_new_kernel_t)(unsigned long indirection_page,
     24				      unsigned long reboot_code_buffer,
     25				      unsigned long start_address);
     26
     27extern const unsigned char relocate_new_kernel[];
     28extern const unsigned int relocate_new_kernel_size;
     29extern void *vbr_base;
     30
     31void native_machine_crash_shutdown(struct pt_regs *regs)
     32{
     33	/* Nothing to do for UP, but definitely broken for SMP.. */
     34}
     35
     36/*
     37 * Do what every setup is needed on image and the
     38 * reboot code buffer to allow us to avoid allocations
     39 * later.
     40 */
     41int machine_kexec_prepare(struct kimage *image)
     42{
     43	return 0;
     44}
     45
     46void machine_kexec_cleanup(struct kimage *image)
     47{
     48}
     49
     50static void kexec_info(struct kimage *image)
     51{
     52        int i;
     53	printk("kexec information\n");
     54	for (i = 0; i < image->nr_segments; i++) {
     55	        printk("  segment[%d]: 0x%08x - 0x%08x (0x%08x)\n",
     56		       i,
     57		       (unsigned int)image->segment[i].mem,
     58		       (unsigned int)image->segment[i].mem +
     59				     image->segment[i].memsz,
     60		       (unsigned int)image->segment[i].memsz);
     61	}
     62	printk("  start     : 0x%08x\n\n", (unsigned int)image->start);
     63}
     64
     65/*
     66 * Do not allocate memory (or fail in any way) in machine_kexec().
     67 * We are past the point of no return, committed to rebooting now.
     68 */
     69void machine_kexec(struct kimage *image)
     70{
     71	unsigned long page_list;
     72	unsigned long reboot_code_buffer;
     73	relocate_new_kernel_t rnk;
     74	unsigned long entry;
     75	unsigned long *ptr;
     76	int save_ftrace_enabled;
     77
     78	/*
     79	 * Nicked from the mips version of machine_kexec():
     80	 * The generic kexec code builds a page list with physical
     81	 * addresses. Use phys_to_virt() to convert them to virtual.
     82	 */
     83	for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
     84	     ptr = (entry & IND_INDIRECTION) ?
     85	       phys_to_virt(entry & PAGE_MASK) : ptr + 1) {
     86		if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
     87		    *ptr & IND_DESTINATION)
     88			*ptr = (unsigned long) phys_to_virt(*ptr);
     89	}
     90
     91#ifdef CONFIG_KEXEC_JUMP
     92	if (image->preserve_context)
     93		save_processor_state();
     94#endif
     95
     96	save_ftrace_enabled = __ftrace_enabled_save();
     97
     98	/* Interrupts aren't acceptable while we reboot */
     99	local_irq_disable();
    100
    101	page_list = image->head;
    102
    103	/* we need both effective and real address here */
    104	reboot_code_buffer =
    105			(unsigned long)page_address(image->control_code_page);
    106
    107	/* copy our kernel relocation code to the control code page */
    108	memcpy((void *)reboot_code_buffer, relocate_new_kernel,
    109						relocate_new_kernel_size);
    110
    111	kexec_info(image);
    112	flush_cache_all();
    113
    114	sh_bios_vbr_reload();
    115
    116	/* now call it */
    117	rnk = (relocate_new_kernel_t) reboot_code_buffer;
    118	(*rnk)(page_list, reboot_code_buffer,
    119	       (unsigned long)phys_to_virt(image->start));
    120
    121#ifdef CONFIG_KEXEC_JUMP
    122	asm volatile("ldc %0, vbr" : : "r" (&vbr_base) : "memory");
    123
    124	if (image->preserve_context)
    125		restore_processor_state();
    126
    127	/* Convert page list back to physical addresses, what a mess. */
    128	for (ptr = &image->head; (entry = *ptr) && !(entry & IND_DONE);
    129	     ptr = (*ptr & IND_INDIRECTION) ?
    130	       phys_to_virt(*ptr & PAGE_MASK) : ptr + 1) {
    131		if (*ptr & IND_SOURCE || *ptr & IND_INDIRECTION ||
    132		    *ptr & IND_DESTINATION)
    133			*ptr = virt_to_phys(*ptr);
    134	}
    135#endif
    136
    137	__ftrace_enabled_restore(save_ftrace_enabled);
    138}
    139
    140void arch_crash_save_vmcoreinfo(void)
    141{
    142#ifdef CONFIG_NUMA
    143	VMCOREINFO_SYMBOL(node_data);
    144	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
    145#endif
    146#ifdef CONFIG_X2TLB
    147	VMCOREINFO_CONFIG(X2TLB);
    148#endif
    149}
    150
    151void __init reserve_crashkernel(void)
    152{
    153	unsigned long long crash_size, crash_base;
    154	int ret;
    155
    156	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
    157			&crash_size, &crash_base);
    158	if (ret == 0 && crash_size > 0) {
    159		crashk_res.start = crash_base;
    160		crashk_res.end = crash_base + crash_size - 1;
    161	}
    162
    163	if (crashk_res.end == crashk_res.start)
    164		goto disable;
    165
    166	crash_size = PAGE_ALIGN(resource_size(&crashk_res));
    167	if (!crashk_res.start) {
    168		unsigned long max = memblock_end_of_DRAM() - memory_limit;
    169		crashk_res.start = memblock_phys_alloc_range(crash_size,
    170							     PAGE_SIZE, 0, max);
    171		if (!crashk_res.start) {
    172			pr_err("crashkernel allocation failed\n");
    173			goto disable;
    174		}
    175	} else {
    176		ret = memblock_reserve(crashk_res.start, crash_size);
    177		if (unlikely(ret < 0)) {
    178			pr_err("crashkernel reservation failed - "
    179			       "memory is in use\n");
    180			goto disable;
    181		}
    182	}
    183
    184	crashk_res.end = crashk_res.start + crash_size - 1;
    185
    186	/*
    187	 * Crash kernel trumps memory limit
    188	 */
    189	if ((memblock_end_of_DRAM() - memory_limit) <= crashk_res.end) {
    190		memory_limit = 0;
    191		pr_info("Disabled memory limit for crashkernel\n");
    192	}
    193
    194	pr_info("Reserving %ldMB of memory at 0x%08lx "
    195		"for crashkernel (System RAM: %ldMB)\n",
    196		(unsigned long)(crash_size >> 20),
    197		(unsigned long)(crashk_res.start),
    198		(unsigned long)(memblock_phys_mem_size() >> 20));
    199
    200	return;
    201
    202disable:
    203	crashk_res.start = crashk_res.end = 0;
    204}