linux/arch/arm64/kernel/machine_kexec.c
Will Deacon 81444b77a4 Merge branch 'for-next/misc' into for-next/core
* for-next/misc:
  arm64: kexec: include reboot.h
  arm64: delete dead code in this_cpu_set_vectors()
  arm64: kernel: Fix kernel warning when nokaslr is passed to commandline
  arm64: kgdb: Set PSTATE.SS to 1 to re-enable single-step
  arm64/sme: Fix some comments of ARM SME
  arm64/signal: Alloc tpidr2 sigframe after checking system_supports_tpidr2()
  arm64/signal: Use system_supports_tpidr2() to check TPIDR2
  arm64: compat: Remove defines now in asm-generic
  arm64: kexec: remove unnecessary (void*) conversions
  arm64: armv8_deprecated: remove unnecessary (void*) conversions
  firmware: arm_sdei: Fix sleep from invalid context BUG
2023-04-20 11:22:09 +01:00

345 lines
8.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* kexec for arm64
*
* Copyright (C) Linaro.
* Copyright (C) Huawei Futurewei Technologies.
*/
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/kexec.h>
#include <linux/page-flags.h>
#include <linux/reboot.h>
#include <linux/set_memory.h>
#include <linux/smp.h>
#include <asm/cacheflush.h>
#include <asm/cpu_ops.h>
#include <asm/daifflags.h>
#include <asm/memory.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/page.h>
#include <asm/sections.h>
#include <asm/trans_pgd.h>
/**
* kexec_image_info - For debugging output.
*/
#define kexec_image_info(_i) _kexec_image_info(__func__, __LINE__, _i)
static void _kexec_image_info(const char *func, int line,
const struct kimage *kimage)
{
unsigned long i;
pr_debug("%s:%d:\n", func, line);
pr_debug(" kexec kimage info:\n");
pr_debug(" type: %d\n", kimage->type);
pr_debug(" start: %lx\n", kimage->start);
pr_debug(" head: %lx\n", kimage->head);
pr_debug(" nr_segments: %lu\n", kimage->nr_segments);
pr_debug(" dtb_mem: %pa\n", &kimage->arch.dtb_mem);
pr_debug(" kern_reloc: %pa\n", &kimage->arch.kern_reloc);
pr_debug(" el2_vectors: %pa\n", &kimage->arch.el2_vectors);
for (i = 0; i < kimage->nr_segments; i++) {
pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
i,
kimage->segment[i].mem,
kimage->segment[i].mem + kimage->segment[i].memsz,
kimage->segment[i].memsz,
kimage->segment[i].memsz / PAGE_SIZE);
}
}
void machine_kexec_cleanup(struct kimage *kimage)
{
/* Empty routine needed to avoid build errors. */
}
/**
* machine_kexec_prepare - Prepare for a kexec reboot.
*
* Called from the core kexec code when a kernel image is loaded.
* Forbid loading a kexec kernel if we have no way of hotplugging cpus or cpus
* are stuck in the kernel. This avoids a panic once we hit machine_kexec().
*/
int machine_kexec_prepare(struct kimage *kimage)
{
if (kimage->type != KEXEC_TYPE_CRASH && cpus_are_stuck_in_kernel()) {
pr_err("Can't kexec: CPUs are stuck in the kernel.\n");
return -EBUSY;
}
return 0;
}
/**
* kexec_segment_flush - Helper to flush the kimage segments to PoC.
*/
static void kexec_segment_flush(const struct kimage *kimage)
{
unsigned long i;
pr_debug("%s:\n", __func__);
for (i = 0; i < kimage->nr_segments; i++) {
pr_debug(" segment[%lu]: %016lx - %016lx, 0x%lx bytes, %lu pages\n",
i,
kimage->segment[i].mem,
kimage->segment[i].mem + kimage->segment[i].memsz,
kimage->segment[i].memsz,
kimage->segment[i].memsz / PAGE_SIZE);
dcache_clean_inval_poc(
(unsigned long)phys_to_virt(kimage->segment[i].mem),
(unsigned long)phys_to_virt(kimage->segment[i].mem) +
kimage->segment[i].memsz);
}
}
/* Allocates pages for kexec page table */
static void *kexec_page_alloc(void *arg)
{
struct kimage *kimage = arg;
struct page *page = kimage_alloc_control_pages(kimage, 0);
void *vaddr = NULL;
if (!page)
return NULL;
vaddr = page_address(page);
memset(vaddr, 0, PAGE_SIZE);
return vaddr;
}
int machine_kexec_post_load(struct kimage *kimage)
{
int rc;
pgd_t *trans_pgd;
void *reloc_code = page_to_virt(kimage->control_code_page);
long reloc_size;
struct trans_pgd_info info = {
.trans_alloc_page = kexec_page_alloc,
.trans_alloc_arg = kimage,
};
/* If in place, relocation is not used, only flush next kernel */
if (kimage->head & IND_DONE) {
kexec_segment_flush(kimage);
kexec_image_info(kimage);
return 0;
}
kimage->arch.el2_vectors = 0;
if (is_hyp_nvhe()) {
rc = trans_pgd_copy_el2_vectors(&info,
&kimage->arch.el2_vectors);
if (rc)
return rc;
}
/* Create a copy of the linear map */
trans_pgd = kexec_page_alloc(kimage);
if (!trans_pgd)
return -ENOMEM;
rc = trans_pgd_create_copy(&info, &trans_pgd, PAGE_OFFSET, PAGE_END);
if (rc)
return rc;
kimage->arch.ttbr1 = __pa(trans_pgd);
kimage->arch.zero_page = __pa_symbol(empty_zero_page);
reloc_size = __relocate_new_kernel_end - __relocate_new_kernel_start;
memcpy(reloc_code, __relocate_new_kernel_start, reloc_size);
kimage->arch.kern_reloc = __pa(reloc_code);
rc = trans_pgd_idmap_page(&info, &kimage->arch.ttbr0,
&kimage->arch.t0sz, reloc_code);
if (rc)
return rc;
kimage->arch.phys_offset = virt_to_phys(kimage) - (long)kimage;
/* Flush the reloc_code in preparation for its execution. */
dcache_clean_inval_poc((unsigned long)reloc_code,
(unsigned long)reloc_code + reloc_size);
icache_inval_pou((uintptr_t)reloc_code,
(uintptr_t)reloc_code + reloc_size);
kexec_image_info(kimage);
return 0;
}
/**
* machine_kexec - Do the kexec reboot.
*
* Called from the core kexec code for a sys_reboot with LINUX_REBOOT_CMD_KEXEC.
*/
void machine_kexec(struct kimage *kimage)
{
bool in_kexec_crash = (kimage == kexec_crash_image);
bool stuck_cpus = cpus_are_stuck_in_kernel();
/*
* New cpus may have become stuck_in_kernel after we loaded the image.
*/
BUG_ON(!in_kexec_crash && (stuck_cpus || (num_online_cpus() > 1)));
WARN(in_kexec_crash && (stuck_cpus || smp_crash_stop_failed()),
"Some CPUs may be stale, kdump will be unreliable.\n");
pr_info("Bye!\n");
local_daif_mask();
/*
* Both restart and kernel_reloc will shutdown the MMU, disable data
* caches. However, restart will start new kernel or purgatory directly,
* kernel_reloc contains the body of arm64_relocate_new_kernel
* In kexec case, kimage->start points to purgatory assuming that
* kernel entry and dtb address are embedded in purgatory by
* userspace (kexec-tools).
* In kexec_file case, the kernel starts directly without purgatory.
*/
if (kimage->head & IND_DONE) {
typeof(cpu_soft_restart) *restart;
cpu_install_idmap();
restart = (void *)__pa_symbol(cpu_soft_restart);
restart(is_hyp_nvhe(), kimage->start, kimage->arch.dtb_mem,
0, 0);
} else {
void (*kernel_reloc)(struct kimage *kimage);
if (is_hyp_nvhe())
__hyp_set_vectors(kimage->arch.el2_vectors);
cpu_install_ttbr0(kimage->arch.ttbr0, kimage->arch.t0sz);
kernel_reloc = (void *)kimage->arch.kern_reloc;
kernel_reloc(kimage);
}
BUG(); /* Should never get here. */
}
static void machine_kexec_mask_interrupts(void)
{
unsigned int i;
struct irq_desc *desc;
for_each_irq_desc(i, desc) {
struct irq_chip *chip;
int ret;
chip = irq_desc_get_chip(desc);
if (!chip)
continue;
/*
* First try to remove the active state. If this
* fails, try to EOI the interrupt.
*/
ret = irq_set_irqchip_state(i, IRQCHIP_STATE_ACTIVE, false);
if (ret && irqd_irq_inprogress(&desc->irq_data) &&
chip->irq_eoi)
chip->irq_eoi(&desc->irq_data);
if (chip->irq_mask)
chip->irq_mask(&desc->irq_data);
if (chip->irq_disable && !irqd_irq_disabled(&desc->irq_data))
chip->irq_disable(&desc->irq_data);
}
}
/**
* machine_crash_shutdown - shutdown non-crashing cpus and save registers
*/
void machine_crash_shutdown(struct pt_regs *regs)
{
local_irq_disable();
/* shutdown non-crashing cpus */
crash_smp_send_stop();
/* for crashing cpu */
crash_save_cpu(regs, smp_processor_id());
machine_kexec_mask_interrupts();
pr_info("Starting crashdump kernel...\n");
}
#ifdef CONFIG_HIBERNATION
/*
* To preserve the crash dump kernel image, the relevant memory segments
* should be mapped again around the hibernation.
*/
void crash_prepare_suspend(void)
{
if (kexec_crash_image)
arch_kexec_unprotect_crashkres();
}
void crash_post_resume(void)
{
if (kexec_crash_image)
arch_kexec_protect_crashkres();
}
/*
* crash_is_nosave
*
* Return true only if a page is part of reserved memory for crash dump kernel,
* but does not hold any data of loaded kernel image.
*
* Note that all the pages in crash dump kernel memory have been initially
* marked as Reserved as memory was allocated via memblock_reserve().
*
* In hibernation, the pages which are Reserved and yet "nosave" are excluded
* from the hibernation iamge. crash_is_nosave() does thich check for crash
* dump kernel and will reduce the total size of hibernation image.
*/
bool crash_is_nosave(unsigned long pfn)
{
int i;
phys_addr_t addr;
if (!crashk_res.end)
return false;
/* in reserved memory? */
addr = __pfn_to_phys(pfn);
if ((addr < crashk_res.start) || (crashk_res.end < addr)) {
if (!crashk_low_res.end)
return false;
if ((addr < crashk_low_res.start) || (crashk_low_res.end < addr))
return false;
}
if (!kexec_crash_image)
return true;
/* not part of loaded kernel image? */
for (i = 0; i < kexec_crash_image->nr_segments; i++)
if (addr >= kexec_crash_image->segment[i].mem &&
addr < (kexec_crash_image->segment[i].mem +
kexec_crash_image->segment[i].memsz))
return false;
return true;
}
void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
{
unsigned long addr;
struct page *page;
for (addr = begin; addr < end; addr += PAGE_SIZE) {
page = phys_to_page(addr);
free_reserved_page(page);
}
}
#endif /* CONFIG_HIBERNATION */