diff options
| -rw-r--r-- | arch/powerpc/platforms/pseries/phyp_dump.c | 81 |
1 files changed, 76 insertions, 5 deletions
diff --git a/arch/powerpc/platforms/pseries/phyp_dump.c b/arch/powerpc/platforms/pseries/phyp_dump.c index 230286cafff..f355f052a56 100644 --- a/arch/powerpc/platforms/pseries/phyp_dump.c +++ b/arch/powerpc/platforms/pseries/phyp_dump.c @@ -12,19 +12,24 @@ */ #include <linux/init.h> +#include <linux/kobject.h> #include <linux/mm.h> +#include <linux/of.h> #include <linux/pfn.h> #include <linux/swap.h> +#include <linux/sysfs.h> #include <asm/page.h> #include <asm/phyp_dump.h> #include <asm/machdep.h> #include <asm/prom.h> +#include <asm/rtas.h> /* Variables, used to communicate data between early boot and late boot */ static struct phyp_dump phyp_dump_vars; struct phyp_dump *phyp_dump_info = &phyp_dump_vars; +/* ------------------------------------------------- */ /** * release_memory_range -- release memory previously lmb_reserved * @start_pfn: starting physical frame number @@ -54,18 +59,84 @@ release_memory_range(unsigned long start_pfn, unsigned long nr_pages) } } -static int __init phyp_dump_setup(void) +/* ------------------------------------------------- */ +/** + * sysfs_release_region -- sysfs interface to release memory range. + * + * Usage: + * "echo <start addr> <length> > /sys/kernel/release_region" + * + * Example: + * "echo 0x40000000 0x10000000 > /sys/kernel/release_region" + * + * will release 256MB starting at 1GB. + */ +static ssize_t store_release_region(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) { + unsigned long start_addr, length, end_addr; unsigned long start_pfn, nr_pages; + ssize_t ret; + + ret = sscanf(buf, "%lx %lx", &start_addr, &length); + if (ret != 2) + return -EINVAL; + + /* Range-check - don't free any reserved memory that + * wasn't reserved for phyp-dump */ + if (start_addr < phyp_dump_info->init_reserve_start) + start_addr = phyp_dump_info->init_reserve_start; + + end_addr = phyp_dump_info->init_reserve_start + + phyp_dump_info->init_reserve_size; + if (start_addr+length > end_addr) + length = end_addr - start_addr; + + /* Release the region of memory assed in by user */ + start_pfn = PFN_DOWN(start_addr); + nr_pages = PFN_DOWN(length); + release_memory_range(start_pfn, nr_pages); + + return count; +} + +static struct kobj_attribute rr = __ATTR(release_region, 0600, + NULL, store_release_region); + +static int __init phyp_dump_setup(void) +{ + struct device_node *rtas; + const int *dump_header = NULL; + int header_len = 0; + int rc; /* If no memory was reserved in early boot, there is nothing to do */ if (phyp_dump_info->init_reserve_size == 0) return 0; - /* Release memory that was reserved in early boot */ - start_pfn = PFN_DOWN(phyp_dump_info->init_reserve_start); - nr_pages = PFN_DOWN(phyp_dump_info->init_reserve_size); - release_memory_range(start_pfn, nr_pages); + /* Return if phyp dump not supported */ + if (!phyp_dump_info->phyp_dump_configured) + return -ENOSYS; + + /* Is there dump data waiting for us? */ + rtas = of_find_node_by_path("/rtas"); + if (rtas) { + dump_header = of_get_property(rtas, "ibm,kernel-dump", + &header_len); + of_node_put(rtas); + } + + if (dump_header == NULL) + return 0; + + /* Should we create a dump_subsys, analogous to s390/ipl.c ? */ + rc = sysfs_create_file(kernel_kobj, &rr.attr); + if (rc) { + printk(KERN_ERR "phyp-dump: unable to create sysfs file (%d)\n", + rc); + return 0; + } return 0; } |