diff options
Diffstat (limited to 'arch/powerpc/kernel/machine_kexec_64.c')
-rw-r--r-- | arch/powerpc/kernel/machine_kexec_64.c | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c new file mode 100644 index 000000000000..97c51e452be7 --- /dev/null +++ b/arch/powerpc/kernel/machine_kexec_64.c @@ -0,0 +1,358 @@ +/* + * 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> +#include <asm/smp.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.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 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 */ +} + +/* Values we need to export to the second kernel via the device tree. */ +static unsigned long htab_base, htab_size, 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, +}; + +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); + + htab_size = 1UL << ppc64_pft_size; + prom_add_property(node, &htab_size_prop); + + out: + of_node_put(node); +} + +void __init kexec_setup(void) +{ + export_htab_values(); +} |