![Michael Ellerman](/assets/img/avatar_default.png)
Implementing the machine_crash_shutdown which will be called by crash_kexec (called in case of a panic, sysrq etc.). Disable the interrupts, shootdown cpus using debugger IPI and collect regs for all CPUs. elfcorehdr= specifies the location of elf core header stored by the crashed kernel. This command line option will be passed by the kexec-tools to capture kernel. savemaxmem= specifies the actual memory size that the first kernel has and this value will be used for dumping in the capture kernel. This command line option will be passed by the kexec-tools to capture kernel. Signed-off-by: Haren Myneni <haren@us.ibm.com> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
346 lines
8.6 KiB
C
346 lines
8.6 KiB
C
/*
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* PPC64 code to handle Linux booting another kernel.
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*
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* Copyright (C) 2004-2005, IBM Corp.
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*
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* Created by: Milton D Miller II
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*
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* This source code is licensed under the GNU General Public License,
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* Version 2. See the file COPYING for more details.
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*/
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#include <linux/cpumask.h>
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#include <linux/kexec.h>
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#include <linux/smp.h>
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#include <linux/thread_info.h>
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#include <linux/errno.h>
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#include <asm/page.h>
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#include <asm/current.h>
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#include <asm/machdep.h>
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#include <asm/cacheflush.h>
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#include <asm/paca.h>
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#include <asm/mmu.h>
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#include <asm/sections.h> /* _end */
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#include <asm/prom.h>
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#include <asm/smp.h>
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#define HASH_GROUP_SIZE 0x80 /* size of each hash group, asm/mmu.h */
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int default_machine_kexec_prepare(struct kimage *image)
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{
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int i;
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unsigned long begin, end; /* limits of segment */
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unsigned long low, high; /* limits of blocked memory range */
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struct device_node *node;
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unsigned long *basep;
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unsigned int *sizep;
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if (!ppc_md.hpte_clear_all)
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return -ENOENT;
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/*
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* Since we use the kernel fault handlers and paging code to
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* handle the virtual mode, we must make sure no destination
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* overlaps kernel static data or bss.
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*/
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for (i = 0; i < image->nr_segments; i++)
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if (image->segment[i].mem < __pa(_end))
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return -ETXTBSY;
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/*
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* For non-LPAR, we absolutely can not overwrite the mmu hash
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* table, since we are still using the bolted entries in it to
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* do the copy. Check that here.
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*
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* It is safe if the end is below the start of the blocked
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* region (end <= low), or if the beginning is after the
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* end of the blocked region (begin >= high). Use the
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* boolean identity !(a || b) === (!a && !b).
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*/
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if (htab_address) {
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low = __pa(htab_address);
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high = low + (htab_hash_mask + 1) * HASH_GROUP_SIZE;
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for (i = 0; i < image->nr_segments; i++) {
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begin = image->segment[i].mem;
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end = begin + image->segment[i].memsz;
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if ((begin < high) && (end > low))
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return -ETXTBSY;
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}
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}
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/* We also should not overwrite the tce tables */
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for (node = of_find_node_by_type(NULL, "pci"); node != NULL;
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node = of_find_node_by_type(node, "pci")) {
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basep = (unsigned long *)get_property(node, "linux,tce-base",
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NULL);
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sizep = (unsigned int *)get_property(node, "linux,tce-size",
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NULL);
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if (basep == NULL || sizep == NULL)
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continue;
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low = *basep;
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high = low + (*sizep);
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for (i = 0; i < image->nr_segments; i++) {
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begin = image->segment[i].mem;
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end = begin + image->segment[i].memsz;
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if ((begin < high) && (end > low))
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return -ETXTBSY;
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}
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}
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return 0;
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}
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#define IND_FLAGS (IND_DESTINATION | IND_INDIRECTION | IND_DONE | IND_SOURCE)
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static void copy_segments(unsigned long ind)
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{
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unsigned long entry;
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unsigned long *ptr;
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void *dest;
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void *addr;
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/*
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* We rely on kexec_load to create a lists that properly
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* initializes these pointers before they are used.
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* We will still crash if the list is wrong, but at least
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* the compiler will be quiet.
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*/
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ptr = NULL;
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dest = NULL;
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for (entry = ind; !(entry & IND_DONE); entry = *ptr++) {
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addr = __va(entry & PAGE_MASK);
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switch (entry & IND_FLAGS) {
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case IND_DESTINATION:
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dest = addr;
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break;
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case IND_INDIRECTION:
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ptr = addr;
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break;
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case IND_SOURCE:
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copy_page(dest, addr);
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dest += PAGE_SIZE;
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}
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}
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}
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void kexec_copy_flush(struct kimage *image)
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{
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long i, nr_segments = image->nr_segments;
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struct kexec_segment ranges[KEXEC_SEGMENT_MAX];
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/* save the ranges on the stack to efficiently flush the icache */
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memcpy(ranges, image->segment, sizeof(ranges));
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/*
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* After this call we may not use anything allocated in dynamic
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* memory, including *image.
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*
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* Only globals and the stack are allowed.
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*/
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copy_segments(image->head);
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/*
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* we need to clear the icache for all dest pages sometime,
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* including ones that were in place on the original copy
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*/
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for (i = 0; i < nr_segments; i++)
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flush_icache_range((unsigned long)__va(ranges[i].mem),
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(unsigned long)__va(ranges[i].mem + ranges[i].memsz));
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}
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#ifdef CONFIG_SMP
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/* FIXME: we should schedule this function to be called on all cpus based
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* on calling the interrupts, but we would like to call it off irq level
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* so that the interrupt controller is clean.
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*/
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void kexec_smp_down(void *arg)
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{
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if (ppc_md.kexec_cpu_down)
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ppc_md.kexec_cpu_down(0, 1);
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local_irq_disable();
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kexec_smp_wait();
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/* NOTREACHED */
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}
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static void kexec_prepare_cpus(void)
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{
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int my_cpu, i, notified=-1;
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smp_call_function(kexec_smp_down, NULL, 0, /* wait */0);
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my_cpu = get_cpu();
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/* check the others cpus are now down (via paca hw cpu id == -1) */
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for (i=0; i < NR_CPUS; i++) {
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if (i == my_cpu)
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continue;
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while (paca[i].hw_cpu_id != -1) {
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barrier();
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if (!cpu_possible(i)) {
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printk("kexec: cpu %d hw_cpu_id %d is not"
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" possible, ignoring\n",
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i, paca[i].hw_cpu_id);
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break;
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}
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if (!cpu_online(i)) {
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/* Fixme: this can be spinning in
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* pSeries_secondary_wait with a paca
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* waiting for it to go online.
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*/
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printk("kexec: cpu %d hw_cpu_id %d is not"
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" online, ignoring\n",
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i, paca[i].hw_cpu_id);
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break;
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}
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if (i != notified) {
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printk( "kexec: waiting for cpu %d (physical"
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" %d) to go down\n",
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i, paca[i].hw_cpu_id);
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notified = i;
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}
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}
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}
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/* after we tell the others to go down */
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if (ppc_md.kexec_cpu_down)
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ppc_md.kexec_cpu_down(0, 0);
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put_cpu();
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local_irq_disable();
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}
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#else /* ! SMP */
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static void kexec_prepare_cpus(void)
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{
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/*
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* move the secondarys to us so that we can copy
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* the new kernel 0-0x100 safely
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*
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* do this if kexec in setup.c ?
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*
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* We need to release the cpus if we are ever going from an
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* UP to an SMP kernel.
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*/
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smp_release_cpus();
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if (ppc_md.kexec_cpu_down)
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ppc_md.kexec_cpu_down(0, 0);
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local_irq_disable();
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}
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#endif /* SMP */
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/*
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* kexec thread structure and stack.
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*
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* We need to make sure that this is 16384-byte aligned due to the
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* way process stacks are handled. It also must be statically allocated
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* or allocated as part of the kimage, because everything else may be
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* overwritten when we copy the kexec image. We piggyback on the
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* "init_task" linker section here to statically allocate a stack.
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*
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* We could use a smaller stack if we don't care about anything using
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* current, but that audit has not been performed.
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*/
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union thread_union kexec_stack
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__attribute__((__section__(".data.init_task"))) = { };
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/* Our assembly helper, in kexec_stub.S */
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extern NORET_TYPE void kexec_sequence(void *newstack, unsigned long start,
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void *image, void *control,
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void (*clear_all)(void)) ATTRIB_NORET;
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/* too late to fail here */
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void default_machine_kexec(struct kimage *image)
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{
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/* prepare control code if any */
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/*
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* If the kexec boot is the normal one, need to shutdown other cpus
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* into our wait loop and quiesce interrupts.
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* Otherwise, in the case of crashed mode (crashing_cpu >= 0),
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* stopping other CPUs and collecting their pt_regs is done before
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* using debugger IPI.
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*/
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if (crashing_cpu == -1)
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kexec_prepare_cpus();
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/* switch to a staticly allocated stack. Based on irq stack code.
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* XXX: the task struct will likely be invalid once we do the copy!
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*/
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kexec_stack.thread_info.task = current_thread_info()->task;
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kexec_stack.thread_info.flags = 0;
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/* Some things are best done in assembly. Finding globals with
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* a toc is easier in C, so pass in what we can.
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*/
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kexec_sequence(&kexec_stack, image->start, image,
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page_address(image->control_code_page),
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ppc_md.hpte_clear_all);
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/* NOTREACHED */
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}
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/* Values we need to export to the second kernel via the device tree. */
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static unsigned long htab_base, htab_size, kernel_end;
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static struct property htab_base_prop = {
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.name = "linux,htab-base",
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.length = sizeof(unsigned long),
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.value = (unsigned char *)&htab_base,
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};
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static struct property htab_size_prop = {
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.name = "linux,htab-size",
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.length = sizeof(unsigned long),
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.value = (unsigned char *)&htab_size,
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};
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static struct property kernel_end_prop = {
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.name = "linux,kernel-end",
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.length = sizeof(unsigned long),
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.value = (unsigned char *)&kernel_end,
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};
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static void __init export_htab_values(void)
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{
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struct device_node *node;
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node = of_find_node_by_path("/chosen");
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if (!node)
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return;
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kernel_end = __pa(_end);
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prom_add_property(node, &kernel_end_prop);
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/* On machines with no htab htab_address is NULL */
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if (NULL == htab_address)
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goto out;
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htab_base = __pa(htab_address);
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prom_add_property(node, &htab_base_prop);
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htab_size = 1UL << ppc64_pft_size;
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prom_add_property(node, &htab_size_prop);
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out:
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of_node_put(node);
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}
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void __init kexec_setup(void)
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{
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export_htab_values();
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}
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