mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Pingfan Liu](/assets/img/avatar_default.png)
'mem=" option is an easy way to put high pressure on memory during some test. Hence after applying the memory limit, instead of total mem, the actual usable memory should be considered when reserving mem for crashkernel. Otherwise the boot up may experience OOM issue. E.g. it would reserve 4G prior to the change and 512M afterward, if passing crashkernel="2G-4G:384M,4G-16G:512M,16G-64G:1G,64G-128G:2G,128G-:4G", and mem=5G on a 256G machine. This issue is powerpc specific because it puts higher priority on fadump and kdump reservation than on "mem=". Referring the following code: if (fadump_reserve_mem() == 0) reserve_crashkernel(); ... /* Ensure that total memory size is page-aligned. */ limit = ALIGN(memory_limit ?: memblock_phys_mem_size(), PAGE_SIZE); memblock_enforce_memory_limit(limit); While on other arches, the effect of "mem=" takes a higher priority and pass through memblock_phys_mem_size() before calling reserve_crashkernel(). Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Reviewed-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1585749644-4148-1-git-send-email-kernelfans@gmail.com
282 lines
7.4 KiB
C
282 lines
7.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Code to handle transition of Linux booting another kernel.
|
|
*
|
|
* Copyright (C) 2002-2003 Eric Biederman <ebiederm@xmission.com>
|
|
* GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
|
|
* Copyright (C) 2005 IBM Corporation.
|
|
*/
|
|
|
|
#include <linux/kexec.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/threads.h>
|
|
#include <linux/memblock.h>
|
|
#include <linux/of.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/ftrace.h>
|
|
|
|
#include <asm/kdump.h>
|
|
#include <asm/machdep.h>
|
|
#include <asm/pgalloc.h>
|
|
#include <asm/prom.h>
|
|
#include <asm/sections.h>
|
|
|
|
void machine_kexec_mask_interrupts(void) {
|
|
unsigned int i;
|
|
struct irq_desc *desc;
|
|
|
|
for_each_irq_desc(i, desc) {
|
|
struct irq_chip *chip;
|
|
|
|
chip = irq_desc_get_chip(desc);
|
|
if (!chip)
|
|
continue;
|
|
|
|
if (chip->irq_eoi && irqd_irq_inprogress(&desc->irq_data))
|
|
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);
|
|
}
|
|
}
|
|
|
|
void machine_crash_shutdown(struct pt_regs *regs)
|
|
{
|
|
default_machine_crash_shutdown(regs);
|
|
}
|
|
|
|
/*
|
|
* Do what every setup is needed on image and the
|
|
* reboot code buffer to allow us to avoid allocations
|
|
* later.
|
|
*/
|
|
int machine_kexec_prepare(struct kimage *image)
|
|
{
|
|
if (ppc_md.machine_kexec_prepare)
|
|
return ppc_md.machine_kexec_prepare(image);
|
|
else
|
|
return default_machine_kexec_prepare(image);
|
|
}
|
|
|
|
void machine_kexec_cleanup(struct kimage *image)
|
|
{
|
|
}
|
|
|
|
void arch_crash_save_vmcoreinfo(void)
|
|
{
|
|
|
|
#ifdef CONFIG_NEED_MULTIPLE_NODES
|
|
VMCOREINFO_SYMBOL(node_data);
|
|
VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
|
|
#endif
|
|
#ifndef CONFIG_NEED_MULTIPLE_NODES
|
|
VMCOREINFO_SYMBOL(contig_page_data);
|
|
#endif
|
|
#if defined(CONFIG_PPC64) && defined(CONFIG_SPARSEMEM_VMEMMAP)
|
|
VMCOREINFO_SYMBOL(vmemmap_list);
|
|
VMCOREINFO_SYMBOL(mmu_vmemmap_psize);
|
|
VMCOREINFO_SYMBOL(mmu_psize_defs);
|
|
VMCOREINFO_STRUCT_SIZE(vmemmap_backing);
|
|
VMCOREINFO_OFFSET(vmemmap_backing, list);
|
|
VMCOREINFO_OFFSET(vmemmap_backing, phys);
|
|
VMCOREINFO_OFFSET(vmemmap_backing, virt_addr);
|
|
VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
|
|
VMCOREINFO_OFFSET(mmu_psize_def, shift);
|
|
#endif
|
|
vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
|
|
}
|
|
|
|
/*
|
|
* Do not allocate memory (or fail in any way) in machine_kexec().
|
|
* We are past the point of no return, committed to rebooting now.
|
|
*/
|
|
void machine_kexec(struct kimage *image)
|
|
{
|
|
int save_ftrace_enabled;
|
|
|
|
save_ftrace_enabled = __ftrace_enabled_save();
|
|
this_cpu_disable_ftrace();
|
|
|
|
if (ppc_md.machine_kexec)
|
|
ppc_md.machine_kexec(image);
|
|
else
|
|
default_machine_kexec(image);
|
|
|
|
this_cpu_enable_ftrace();
|
|
__ftrace_enabled_restore(save_ftrace_enabled);
|
|
|
|
/* Fall back to normal restart if we're still alive. */
|
|
machine_restart(NULL);
|
|
for(;;);
|
|
}
|
|
|
|
void __init reserve_crashkernel(void)
|
|
{
|
|
unsigned long long crash_size, crash_base, total_mem_sz;
|
|
int ret;
|
|
|
|
total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();
|
|
/* use common parsing */
|
|
ret = parse_crashkernel(boot_command_line, total_mem_sz,
|
|
&crash_size, &crash_base);
|
|
if (ret == 0 && crash_size > 0) {
|
|
crashk_res.start = crash_base;
|
|
crashk_res.end = crash_base + crash_size - 1;
|
|
}
|
|
|
|
if (crashk_res.end == crashk_res.start) {
|
|
crashk_res.start = crashk_res.end = 0;
|
|
return;
|
|
}
|
|
|
|
/* We might have got these values via the command line or the
|
|
* device tree, either way sanitise them now. */
|
|
|
|
crash_size = resource_size(&crashk_res);
|
|
|
|
#ifndef CONFIG_NONSTATIC_KERNEL
|
|
if (crashk_res.start != KDUMP_KERNELBASE)
|
|
printk("Crash kernel location must be 0x%x\n",
|
|
KDUMP_KERNELBASE);
|
|
|
|
crashk_res.start = KDUMP_KERNELBASE;
|
|
#else
|
|
if (!crashk_res.start) {
|
|
#ifdef CONFIG_PPC64
|
|
/*
|
|
* On 64bit we split the RMO in half but cap it at half of
|
|
* a small SLB (128MB) since the crash kernel needs to place
|
|
* itself and some stacks to be in the first segment.
|
|
*/
|
|
crashk_res.start = min(0x8000000ULL, (ppc64_rma_size / 2));
|
|
#else
|
|
crashk_res.start = KDUMP_KERNELBASE;
|
|
#endif
|
|
}
|
|
|
|
crash_base = PAGE_ALIGN(crashk_res.start);
|
|
if (crash_base != crashk_res.start) {
|
|
printk("Crash kernel base must be aligned to 0x%lx\n",
|
|
PAGE_SIZE);
|
|
crashk_res.start = crash_base;
|
|
}
|
|
|
|
#endif
|
|
crash_size = PAGE_ALIGN(crash_size);
|
|
crashk_res.end = crashk_res.start + crash_size - 1;
|
|
|
|
/* The crash region must not overlap the current kernel */
|
|
if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
|
|
printk(KERN_WARNING
|
|
"Crash kernel can not overlap current kernel\n");
|
|
crashk_res.start = crashk_res.end = 0;
|
|
return;
|
|
}
|
|
|
|
/* Crash kernel trumps memory limit */
|
|
if (memory_limit && memory_limit <= crashk_res.end) {
|
|
memory_limit = crashk_res.end + 1;
|
|
total_mem_sz = memory_limit;
|
|
printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
|
|
memory_limit);
|
|
}
|
|
|
|
printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
|
|
"for crashkernel (System RAM: %ldMB)\n",
|
|
(unsigned long)(crash_size >> 20),
|
|
(unsigned long)(crashk_res.start >> 20),
|
|
(unsigned long)(total_mem_sz >> 20));
|
|
|
|
if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
|
|
memblock_reserve(crashk_res.start, crash_size)) {
|
|
pr_err("Failed to reserve memory for crashkernel!\n");
|
|
crashk_res.start = crashk_res.end = 0;
|
|
return;
|
|
}
|
|
}
|
|
|
|
int overlaps_crashkernel(unsigned long start, unsigned long size)
|
|
{
|
|
return (start + size) > crashk_res.start && start <= crashk_res.end;
|
|
}
|
|
|
|
/* Values we need to export to the second kernel via the device tree. */
|
|
static phys_addr_t kernel_end;
|
|
static phys_addr_t crashk_base;
|
|
static phys_addr_t crashk_size;
|
|
static unsigned long long mem_limit;
|
|
|
|
static struct property kernel_end_prop = {
|
|
.name = "linux,kernel-end",
|
|
.length = sizeof(phys_addr_t),
|
|
.value = &kernel_end,
|
|
};
|
|
|
|
static struct property crashk_base_prop = {
|
|
.name = "linux,crashkernel-base",
|
|
.length = sizeof(phys_addr_t),
|
|
.value = &crashk_base
|
|
};
|
|
|
|
static struct property crashk_size_prop = {
|
|
.name = "linux,crashkernel-size",
|
|
.length = sizeof(phys_addr_t),
|
|
.value = &crashk_size,
|
|
};
|
|
|
|
static struct property memory_limit_prop = {
|
|
.name = "linux,memory-limit",
|
|
.length = sizeof(unsigned long long),
|
|
.value = &mem_limit,
|
|
};
|
|
|
|
#define cpu_to_be_ulong __PASTE(cpu_to_be, BITS_PER_LONG)
|
|
|
|
static void __init export_crashk_values(struct device_node *node)
|
|
{
|
|
/* There might be existing crash kernel properties, but we can't
|
|
* be sure what's in them, so remove them. */
|
|
of_remove_property(node, of_find_property(node,
|
|
"linux,crashkernel-base", NULL));
|
|
of_remove_property(node, of_find_property(node,
|
|
"linux,crashkernel-size", NULL));
|
|
|
|
if (crashk_res.start != 0) {
|
|
crashk_base = cpu_to_be_ulong(crashk_res.start),
|
|
of_add_property(node, &crashk_base_prop);
|
|
crashk_size = cpu_to_be_ulong(resource_size(&crashk_res));
|
|
of_add_property(node, &crashk_size_prop);
|
|
}
|
|
|
|
/*
|
|
* memory_limit is required by the kexec-tools to limit the
|
|
* crash regions to the actual memory used.
|
|
*/
|
|
mem_limit = cpu_to_be_ulong(memory_limit);
|
|
of_update_property(node, &memory_limit_prop);
|
|
}
|
|
|
|
static int __init kexec_setup(void)
|
|
{
|
|
struct device_node *node;
|
|
|
|
node = of_find_node_by_path("/chosen");
|
|
if (!node)
|
|
return -ENOENT;
|
|
|
|
/* remove any stale properties so ours can be found */
|
|
of_remove_property(node, of_find_property(node, kernel_end_prop.name, NULL));
|
|
|
|
/* information needed by userspace when using default_machine_kexec */
|
|
kernel_end = cpu_to_be_ulong(__pa(_end));
|
|
of_add_property(node, &kernel_end_prop);
|
|
|
|
export_crashk_values(node);
|
|
|
|
of_node_put(node);
|
|
return 0;
|
|
}
|
|
late_initcall(kexec_setup);
|