--- /dev/null
+/*
+ * PPC64 code to handle 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>
+#include <asm/smp.h>
+
+int default_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_size_bytes;
+
+ 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;
+}
+
+#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((unsigned long)__va(ranges[i].mem),
+ (unsigned long)__va(ranges[i].mem + 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.kexec_cpu_down)
+ ppc_md.kexec_cpu_down(0, 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) {
+ barrier();
+ 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.kexec_cpu_down)
+ ppc_md.kexec_cpu_down(0, 0);
+
+ put_cpu();
+
+ local_irq_disable();
+}
+
+#else /* ! SMP */
+
+static void kexec_prepare_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.kexec_cpu_down)
+ ppc_md.kexec_cpu_down(0, 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 default_machine_kexec(struct kimage *image)
+{
+ /* prepare control code if any */
+
+ /*
+ * If the kexec boot is the normal one, need to shutdown other cpus
+ * into our wait loop and quiesce interrupts.
+ * Otherwise, in the case of crashed mode (crashing_cpu >= 0),
+ * stopping other CPUs and collecting their pt_regs is done before
+ * using debugger IPI.
+ */
+
+ if (crashing_cpu == -1)
+ 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 */
+}
+
+/* Values we need to export to the second kernel via the device tree. */
+static unsigned long htab_base, kernel_end;
+
+static struct property htab_base_prop = {
+ .name = "linux,htab-base",
+ .length = sizeof(unsigned long),
+ .value = (unsigned char *)&htab_base,
+};
+
+static struct property htab_size_prop = {
+ .name = "linux,htab-size",
+ .length = sizeof(unsigned long),
+ .value = (unsigned char *)&htab_size_bytes,
+};
+
+static struct property kernel_end_prop = {
+ .name = "linux,kernel-end",
+ .length = sizeof(unsigned long),
+ .value = (unsigned char *)&kernel_end,
+};
+
+static void __init export_htab_values(void)
+{
+ struct device_node *node;
+
+ node = of_find_node_by_path("/chosen");
+ if (!node)
+ return;
+
+ kernel_end = __pa(_end);
+ prom_add_property(node, &kernel_end_prop);
+
+ /* On machines with no htab htab_address is NULL */
+ if (NULL == htab_address)
+ goto out;
+
+ htab_base = __pa(htab_address);
+ prom_add_property(node, &htab_base_prop);
+ prom_add_property(node, &htab_size_prop);
+
+ out:
+ of_node_put(node);
+}
+
+void __init kexec_setup(void)
+{
+ export_htab_values();
+}
git://git.onelab.eu / linux-2.6.git / blobdiff