342 lines
8.4 KiB
C
342 lines
8.4 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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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_size_bytes;
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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, 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_bytes,
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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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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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