kernel-ark/arch/ppc64/kernel/machine_kexec.c
Paul Mackerras 6d22d85a85 [PATCH] ppc64: fix for kexec boot issue
The kexec boot is not successful on some power machines since all CPUs are
getting removed from global interrupt queue (GIQ) before kexec boot.  Some
systems always expect at least one CPU in GIQ.  Hence, this patch will make
sure that only secondary CPUs are removed from GIQ.

Signed-off-by: Haren Myneni <hbabu@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-04 13:00:55 -07:00

307 lines
7.7 KiB
C

/*
* machine_kexec.c - handle transition of Linux booting another kernel
*
* Copyright (C) 2004-2005, IBM Corp.
*
* Created by: Milton D Miller II
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <linux/cpumask.h>
#include <linux/kexec.h>
#include <linux/smp.h>
#include <linux/thread_info.h>
#include <linux/errno.h>
#include <asm/page.h>
#include <asm/current.h>
#include <asm/machdep.h>
#include <asm/cacheflush.h>
#include <asm/paca.h>
#include <asm/mmu.h>
#include <asm/sections.h> /* _end */
#include <asm/prom.h>
#define HASH_GROUP_SIZE 0x80 /* size of each hash group, asm/mmu.h */
/* Have this around till we move it into crash specific file */
note_buf_t crash_notes[NR_CPUS];
/* Dummy for now. Not sure if we need to have a crash shutdown in here
* and if what it will achieve. Letting it be now to compile the code
* in generic kexec environment
*/
void machine_crash_shutdown(struct pt_regs *regs)
{
/* do nothing right now */
/* smp_relase_cpus() if we want smp on panic kernel */
/* cpu_irq_down to isolate us until we are ready */
}
int machine_kexec_prepare(struct kimage *image)
{
int i;
unsigned long begin, end; /* limits of segment */
unsigned long low, high; /* limits of blocked memory range */
struct device_node *node;
unsigned long *basep;
unsigned int *sizep;
if (!ppc_md.hpte_clear_all)
return -ENOENT;
/*
* Since we use the kernel fault handlers and paging code to
* handle the virtual mode, we must make sure no destination
* overlaps kernel static data or bss.
*/
for (i = 0; i < image->nr_segments; i++)
if (image->segment[i].mem < __pa(_end))
return -ETXTBSY;
/*
* For non-LPAR, we absolutely can not overwrite the mmu hash
* table, since we are still using the bolted entries in it to
* do the copy. Check that here.
*
* It is safe if the end is below the start of the blocked
* region (end <= low), or if the beginning is after the
* end of the blocked region (begin >= high). Use the
* boolean identity !(a || b) === (!a && !b).
*/
if (htab_address) {
low = __pa(htab_address);
high = low + (htab_hash_mask + 1) * HASH_GROUP_SIZE;
for (i = 0; i < image->nr_segments; i++) {
begin = image->segment[i].mem;
end = begin + image->segment[i].memsz;
if ((begin < high) && (end > low))
return -ETXTBSY;
}
}
/* We also should not overwrite the tce tables */
for (node = of_find_node_by_type(NULL, "pci"); node != NULL;
node = of_find_node_by_type(node, "pci")) {
basep = (unsigned long *)get_property(node, "linux,tce-base",
NULL);
sizep = (unsigned int *)get_property(node, "linux,tce-size",
NULL);
if (basep == NULL || sizep == NULL)
continue;
low = *basep;
high = low + (*sizep);
for (i = 0; i < image->nr_segments; i++) {
begin = image->segment[i].mem;
end = begin + image->segment[i].memsz;
if ((begin < high) && (end > low))
return -ETXTBSY;
}
}
return 0;
}
void machine_kexec_cleanup(struct kimage *image)
{
/* we do nothing in prepare that needs to be undone */
}
#define IND_FLAGS (IND_DESTINATION | IND_INDIRECTION | IND_DONE | IND_SOURCE)
static void copy_segments(unsigned long ind)
{
unsigned long entry;
unsigned long *ptr;
void *dest;
void *addr;
/*
* We rely on kexec_load to create a lists that properly
* initializes these pointers before they are used.
* We will still crash if the list is wrong, but at least
* the compiler will be quiet.
*/
ptr = NULL;
dest = NULL;
for (entry = ind; !(entry & IND_DONE); entry = *ptr++) {
addr = __va(entry & PAGE_MASK);
switch (entry & IND_FLAGS) {
case IND_DESTINATION:
dest = addr;
break;
case IND_INDIRECTION:
ptr = addr;
break;
case IND_SOURCE:
copy_page(dest, addr);
dest += PAGE_SIZE;
}
}
}
void kexec_copy_flush(struct kimage *image)
{
long i, nr_segments = image->nr_segments;
struct kexec_segment ranges[KEXEC_SEGMENT_MAX];
/* save the ranges on the stack to efficiently flush the icache */
memcpy(ranges, image->segment, sizeof(ranges));
/*
* After this call we may not use anything allocated in dynamic
* memory, including *image.
*
* Only globals and the stack are allowed.
*/
copy_segments(image->head);
/*
* we need to clear the icache for all dest pages sometime,
* including ones that were in place on the original copy
*/
for (i = 0; i < nr_segments; i++)
flush_icache_range(ranges[i].mem + KERNELBASE,
ranges[i].mem + KERNELBASE +
ranges[i].memsz);
}
#ifdef CONFIG_SMP
/* FIXME: we should schedule this function to be called on all cpus based
* on calling the interrupts, but we would like to call it off irq level
* so that the interrupt controller is clean.
*/
void kexec_smp_down(void *arg)
{
if (ppc_md.cpu_irq_down)
ppc_md.cpu_irq_down(1);
local_irq_disable();
kexec_smp_wait();
/* NOTREACHED */
}
static void kexec_prepare_cpus(void)
{
int my_cpu, i, notified=-1;
smp_call_function(kexec_smp_down, NULL, 0, /* wait */0);
my_cpu = get_cpu();
/* check the others cpus are now down (via paca hw cpu id == -1) */
for (i=0; i < NR_CPUS; i++) {
if (i == my_cpu)
continue;
while (paca[i].hw_cpu_id != -1) {
if (!cpu_possible(i)) {
printk("kexec: cpu %d hw_cpu_id %d is not"
" possible, ignoring\n",
i, paca[i].hw_cpu_id);
break;
}
if (!cpu_online(i)) {
/* Fixme: this can be spinning in
* pSeries_secondary_wait with a paca
* waiting for it to go online.
*/
printk("kexec: cpu %d hw_cpu_id %d is not"
" online, ignoring\n",
i, paca[i].hw_cpu_id);
break;
}
if (i != notified) {
printk( "kexec: waiting for cpu %d (physical"
" %d) to go down\n",
i, paca[i].hw_cpu_id);
notified = i;
}
}
}
/* after we tell the others to go down */
if (ppc_md.cpu_irq_down)
ppc_md.cpu_irq_down(0);
put_cpu();
local_irq_disable();
}
#else /* ! SMP */
static void kexec_prepare_cpus(void)
{
extern void smp_release_cpus(void);
/*
* move the secondarys to us so that we can copy
* the new kernel 0-0x100 safely
*
* do this if kexec in setup.c ?
*
* We need to release the cpus if we are ever going from an
* UP to an SMP kernel.
*/
smp_release_cpus();
if (ppc_md.cpu_irq_down)
ppc_md.cpu_irq_down(0);
local_irq_disable();
}
#endif /* SMP */
/*
* kexec thread structure and stack.
*
* We need to make sure that this is 16384-byte aligned due to the
* way process stacks are handled. It also must be statically allocated
* or allocated as part of the kimage, because everything else may be
* overwritten when we copy the kexec image. We piggyback on the
* "init_task" linker section here to statically allocate a stack.
*
* We could use a smaller stack if we don't care about anything using
* current, but that audit has not been performed.
*/
union thread_union kexec_stack
__attribute__((__section__(".data.init_task"))) = { };
/* Our assembly helper, in kexec_stub.S */
extern NORET_TYPE void kexec_sequence(void *newstack, unsigned long start,
void *image, void *control,
void (*clear_all)(void)) ATTRIB_NORET;
/* too late to fail here */
void machine_kexec(struct kimage *image)
{
/* prepare control code if any */
/* shutdown other cpus into our wait loop and quiesce interrupts */
kexec_prepare_cpus();
/* switch to a staticly allocated stack. Based on irq stack code.
* XXX: the task struct will likely be invalid once we do the copy!
*/
kexec_stack.thread_info.task = current_thread_info()->task;
kexec_stack.thread_info.flags = 0;
/* Some things are best done in assembly. Finding globals with
* a toc is easier in C, so pass in what we can.
*/
kexec_sequence(&kexec_stack, image->start, image,
page_address(image->control_code_page),
ppc_md.hpte_clear_all);
/* NOTREACHED */
}