Linux-2.6.33.2/drivers/s390/char/zcore.c
/*
* zcore module to export memory content and register sets for creating system
* dumps on SCSI disks (zfcpdump). The "zcore/mem" debugfs file shows the same
* dump format as s390 standalone dumps.
*
* For more information please refer to Documentation/s390/zfcpdump.txt
*
* Copyright IBM Corp. 2003,2008
* Author(s): Michael Holzheu
*/
#define KMSG_COMPONENT "zdump"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/debugfs.h>
#include <asm/ipl.h>
#include <asm/sclp.h>
#include <asm/setup.h>
#include <asm/sigp.h>
#include <asm/uaccess.h>
#include <asm/debug.h>
#include <asm/processor.h>
#include <asm/irqflags.h>
#include <asm/checksum.h>
#include "sclp.h"
#define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x)
#define TO_USER 0
#define TO_KERNEL 1
#define CHUNK_INFO_SIZE 34 /* 2 16-byte char, each followed by blank */
enum arch_id {
ARCH_S390 = 0,
ARCH_S390X = 1,
};
/* dump system info */
struct sys_info {
enum arch_id arch;
unsigned long sa_base;
u32 sa_size;
int cpu_map[NR_CPUS];
unsigned long mem_size;
union save_area lc_mask;
};
struct ipib_info {
unsigned long ipib;
u32 checksum;
} __attribute__((packed));
static struct sys_info sys_info;
static struct debug_info *zcore_dbf;
static int hsa_available;
static struct dentry *zcore_dir;
static struct dentry *zcore_file;
static struct dentry *zcore_memmap_file;
static struct dentry *zcore_reipl_file;
static struct ipl_parameter_block *ipl_block;
/*
* Copy memory from HSA to kernel or user memory (not reentrant):
*
* @dest: Kernel or user buffer where memory should be copied to
* @src: Start address within HSA where data should be copied
* @count: Size of buffer, which should be copied
* @mode: Either TO_KERNEL or TO_USER
*/
static int memcpy_hsa(void *dest, unsigned long src, size_t count, int mode)
{
int offs, blk_num;
static char buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
if (count == 0)
return 0;
/* copy first block */
offs = 0;
if ((src % PAGE_SIZE) != 0) {
blk_num = src / PAGE_SIZE + 2;
if (sclp_sdias_copy(buf, blk_num, 1)) {
TRACE("sclp_sdias_copy() failed\n");
return -EIO;
}
offs = min((PAGE_SIZE - (src % PAGE_SIZE)), count);
if (mode == TO_USER) {
if (copy_to_user((__force __user void*) dest,
buf + (src % PAGE_SIZE), offs))
return -EFAULT;
} else
memcpy(dest, buf + (src % PAGE_SIZE), offs);
}
if (offs == count)
goto out;
/* copy middle */
for (; (offs + PAGE_SIZE) <= count; offs += PAGE_SIZE) {
blk_num = (src + offs) / PAGE_SIZE + 2;
if (sclp_sdias_copy(buf, blk_num, 1)) {
TRACE("sclp_sdias_copy() failed\n");
return -EIO;
}
if (mode == TO_USER) {
if (copy_to_user((__force __user void*) dest + offs,
buf, PAGE_SIZE))
return -EFAULT;
} else
memcpy(dest + offs, buf, PAGE_SIZE);
}
if (offs == count)
goto out;
/* copy last block */
blk_num = (src + offs) / PAGE_SIZE + 2;
if (sclp_sdias_copy(buf, blk_num, 1)) {
TRACE("sclp_sdias_copy() failed\n");
return -EIO;
}
if (mode == TO_USER) {
if (copy_to_user((__force __user void*) dest + offs, buf,
PAGE_SIZE))
return -EFAULT;
} else
memcpy(dest + offs, buf, count - offs);
out:
return 0;
}
static int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count)
{
return memcpy_hsa((void __force *) dest, src, count, TO_USER);
}
static int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count)
{
return memcpy_hsa(dest, src, count, TO_KERNEL);
}
static int memcpy_real(void *dest, unsigned long src, size_t count)
{
unsigned long flags;
int rc = -EFAULT;
register unsigned long _dest asm("2") = (unsigned long) dest;
register unsigned long _len1 asm("3") = (unsigned long) count;
register unsigned long _src asm("4") = src;
register unsigned long _len2 asm("5") = (unsigned long) count;
if (count == 0)
return 0;
flags = __raw_local_irq_stnsm(0xf8UL); /* switch to real mode */
asm volatile (
"0: mvcle %1,%2,0x0\n"
"1: jo 0b\n"
" lhi %0,0x0\n"
"2:\n"
EX_TABLE(1b,2b)
: "+d" (rc), "+d" (_dest), "+d" (_src), "+d" (_len1),
"+d" (_len2), "=m" (*((long*)dest))
: "m" (*((long*)src))
: "cc", "memory");
__raw_local_irq_ssm(flags);
return rc;
}
static int memcpy_real_user(void __user *dest, unsigned long src, size_t count)
{
static char buf[4096];
int offs = 0, size;
while (offs < count) {
size = min(sizeof(buf), count - offs);
if (memcpy_real(buf, src + offs, size))
return -EFAULT;
if (copy_to_user(dest + offs, buf, size))
return -EFAULT;
offs += size;
}
return 0;
}
#ifdef __s390x__
/*
* Convert s390x (64 bit) cpu info to s390 (32 bit) cpu info
*/
static void __init s390x_to_s390_regs(union save_area *out, union save_area *in,
int cpu)
{
int i;
for (i = 0; i < 16; i++) {
out->s390.gp_regs[i] = in->s390x.gp_regs[i] & 0x00000000ffffffff;
out->s390.acc_regs[i] = in->s390x.acc_regs[i];
out->s390.ctrl_regs[i] =
in->s390x.ctrl_regs[i] & 0x00000000ffffffff;
}
/* locore for 31 bit has only space for fpregs 0,2,4,6 */
out->s390.fp_regs[0] = in->s390x.fp_regs[0];
out->s390.fp_regs[1] = in->s390x.fp_regs[2];
out->s390.fp_regs[2] = in->s390x.fp_regs[4];
out->s390.fp_regs[3] = in->s390x.fp_regs[6];
memcpy(&(out->s390.psw[0]), &(in->s390x.psw[0]), 4);
out->s390.psw[1] |= 0x8; /* set bit 12 */
memcpy(&(out->s390.psw[4]),&(in->s390x.psw[12]), 4);
out->s390.psw[4] |= 0x80; /* set (31bit) addressing bit */
out->s390.pref_reg = in->s390x.pref_reg;
out->s390.timer = in->s390x.timer;
out->s390.clk_cmp = in->s390x.clk_cmp;
}
static void __init s390x_to_s390_save_areas(void)
{
int i = 1;
static union save_area tmp;
while (zfcpdump_save_areas[i]) {
s390x_to_s390_regs(&tmp, zfcpdump_save_areas[i], i);
memcpy(zfcpdump_save_areas[i], &tmp, sizeof(tmp));
i++;
}
}
#endif /* __s390x__ */
static int __init init_cpu_info(enum arch_id arch)
{
union save_area *sa;
/* get info for boot cpu from lowcore, stored in the HSA */
sa = kmalloc(sizeof(*sa), GFP_KERNEL);
if (!sa)
return -ENOMEM;
if (memcpy_hsa_kernel(sa, sys_info.sa_base, sys_info.sa_size) < 0) {
TRACE("could not copy from HSA\n");
kfree(sa);
return -EIO;
}
zfcpdump_save_areas[0] = sa;
#ifdef __s390x__
/* convert s390x regs to s390, if we are dumping an s390 Linux */
if (arch == ARCH_S390)
s390x_to_s390_save_areas();
#endif
return 0;
}
static DEFINE_MUTEX(zcore_mutex);
#define DUMP_VERSION 0x3
#define DUMP_MAGIC 0xa8190173618f23fdULL
#define DUMP_ARCH_S390X 2
#define DUMP_ARCH_S390 1
#define HEADER_SIZE 4096
/* dump header dumped according to s390 crash dump format */
struct zcore_header {
u64 magic;
u32 version;
u32 header_size;
u32 dump_level;
u32 page_size;
u64 mem_size;
u64 mem_start;
u64 mem_end;
u32 num_pages;
u32 pad1;
u64 tod;
struct cpuid cpu_id;
u32 arch_id;
u32 volnr;
u32 build_arch;
u64 rmem_size;
char pad2[4016];
} __attribute__((packed,__aligned__(16)));
static struct zcore_header zcore_header = {
.magic = DUMP_MAGIC,
.version = DUMP_VERSION,
.header_size = 4096,
.dump_level = 0,
.page_size = PAGE_SIZE,
.mem_start = 0,
#ifdef __s390x__
.build_arch = DUMP_ARCH_S390X,
#else
.build_arch = DUMP_ARCH_S390,
#endif
};
/*
* Copy lowcore info to buffer. Use map in order to copy only register parts.
*
* @buf: User buffer
* @sa: Pointer to save area
* @sa_off: Offset in save area to copy
* @len: Number of bytes to copy
*/
static int copy_lc(void __user *buf, void *sa, int sa_off, int len)
{
int i;
char *lc_mask = (char*)&sys_info.lc_mask;
for (i = 0; i < len; i++) {
if (!lc_mask[i + sa_off])
continue;
if (copy_to_user(buf + i, sa + sa_off + i, 1))
return -EFAULT;
}
return 0;
}
/*
* Copy lowcores info to memory, if necessary
*
* @buf: User buffer
* @addr: Start address of buffer in dump memory
* @count: Size of buffer
*/
static int zcore_add_lc(char __user *buf, unsigned long start, size_t count)
{
unsigned long end;
int i = 0;
if (count == 0)
return 0;
end = start + count;
while (zfcpdump_save_areas[i]) {
unsigned long cp_start, cp_end; /* copy range */
unsigned long sa_start, sa_end; /* save area range */
unsigned long prefix;
unsigned long sa_off, len, buf_off;
if (sys_info.arch == ARCH_S390)
prefix = zfcpdump_save_areas[i]->s390.pref_reg;
else
prefix = zfcpdump_save_areas[i]->s390x.pref_reg;
sa_start = prefix + sys_info.sa_base;
sa_end = prefix + sys_info.sa_base + sys_info.sa_size;
if ((end < sa_start) || (start > sa_end))
goto next;
cp_start = max(start, sa_start);
cp_end = min(end, sa_end);
buf_off = cp_start - start;
sa_off = cp_start - sa_start;
len = cp_end - cp_start;
TRACE("copy_lc for: %lx\n", start);
if (copy_lc(buf + buf_off, zfcpdump_save_areas[i], sa_off, len))
return -EFAULT;
next:
i++;
}
return 0;
}
/*
* Read routine for zcore character device
* First 4K are dump header
* Next 32MB are HSA Memory
* Rest is read from absolute Memory
*/
static ssize_t zcore_read(struct file *file, char __user *buf, size_t count,
loff_t *ppos)
{
unsigned long mem_start; /* Start address in memory */
size_t mem_offs; /* Offset in dump memory */
size_t hdr_count; /* Size of header part of output buffer */
size_t size;
int rc;
mutex_lock(&zcore_mutex);
if (*ppos > (sys_info.mem_size + HEADER_SIZE)) {
rc = -EINVAL;
goto fail;
}
count = min(count, (size_t) (sys_info.mem_size + HEADER_SIZE - *ppos));
/* Copy dump header */
if (*ppos < HEADER_SIZE) {
size = min(count, (size_t) (HEADER_SIZE - *ppos));
if (copy_to_user(buf, &zcore_header + *ppos, size)) {
rc = -EFAULT;
goto fail;
}
hdr_count = size;
mem_start = 0;
} else {
hdr_count = 0;
mem_start = *ppos - HEADER_SIZE;
}
mem_offs = 0;
/* Copy from HSA data */
if (*ppos < (ZFCPDUMP_HSA_SIZE + HEADER_SIZE)) {
size = min((count - hdr_count), (size_t) (ZFCPDUMP_HSA_SIZE
- mem_start));
rc = memcpy_hsa_user(buf + hdr_count, mem_start, size);
if (rc)
goto fail;
mem_offs += size;
}
/* Copy from real mem */
size = count - mem_offs - hdr_count;
rc = memcpy_real_user(buf + hdr_count + mem_offs, mem_start + mem_offs,
size);
if (rc)
goto fail;
/*
* Since s390 dump analysis tools like lcrash or crash
* expect register sets in the prefix pages of the cpus,
* we copy them into the read buffer, if necessary.
* buf + hdr_count: Start of memory part of output buffer
* mem_start: Start memory address to copy from
* count - hdr_count: Size of memory area to copy
*/
if (zcore_add_lc(buf + hdr_count, mem_start, count - hdr_count)) {
rc = -EFAULT;
goto fail;
}
*ppos += count;
fail:
mutex_unlock(&zcore_mutex);
return (rc < 0) ? rc : count;
}
static int zcore_open(struct inode *inode, struct file *filp)
{
if (!hsa_available)
return -ENODATA;
else
return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
}
static int zcore_release(struct inode *inode, struct file *filep)
{
diag308(DIAG308_REL_HSA, NULL);
hsa_available = 0;
return 0;
}
static loff_t zcore_lseek(struct file *file, loff_t offset, int orig)
{
loff_t rc;
mutex_lock(&zcore_mutex);
switch (orig) {
case 0:
file->f_pos = offset;
rc = file->f_pos;
break;
case 1:
file->f_pos += offset;
rc = file->f_pos;
break;
default:
rc = -EINVAL;
}
mutex_unlock(&zcore_mutex);
return rc;
}
static const struct file_operations zcore_fops = {
.owner = THIS_MODULE,
.llseek = zcore_lseek,
.read = zcore_read,
.open = zcore_open,
.release = zcore_release,
};
static ssize_t zcore_memmap_read(struct file *filp, char __user *buf,
size_t count, loff_t *ppos)
{
return simple_read_from_buffer(buf, count, ppos, filp->private_data,
MEMORY_CHUNKS * CHUNK_INFO_SIZE);
}
static int zcore_memmap_open(struct inode *inode, struct file *filp)
{
int i;
char *buf;
struct mem_chunk *chunk_array;
chunk_array = kzalloc(MEMORY_CHUNKS * sizeof(struct mem_chunk),
GFP_KERNEL);
if (!chunk_array)
return -ENOMEM;
detect_memory_layout(chunk_array);
buf = kzalloc(MEMORY_CHUNKS * CHUNK_INFO_SIZE, GFP_KERNEL);
if (!buf) {
kfree(chunk_array);
return -ENOMEM;
}
for (i = 0; i < MEMORY_CHUNKS; i++) {
sprintf(buf + (i * CHUNK_INFO_SIZE), "%016llx %016llx ",
(unsigned long long) chunk_array[i].addr,
(unsigned long long) chunk_array[i].size);
if (chunk_array[i].size == 0)
break;
}
kfree(chunk_array);
filp->private_data = buf;
return 0;
}
static int zcore_memmap_release(struct inode *inode, struct file *filp)
{
kfree(filp->private_data);
return 0;
}
static const struct file_operations zcore_memmap_fops = {
.owner = THIS_MODULE,
.read = zcore_memmap_read,
.open = zcore_memmap_open,
.release = zcore_memmap_release,
};
static ssize_t zcore_reipl_write(struct file *filp, const char __user *buf,
size_t count, loff_t *ppos)
{
if (ipl_block) {
diag308(DIAG308_SET, ipl_block);
diag308(DIAG308_IPL, NULL);
}
return count;
}
static int zcore_reipl_open(struct inode *inode, struct file *filp)
{
return 0;
}
static int zcore_reipl_release(struct inode *inode, struct file *filp)
{
return 0;
}
static const struct file_operations zcore_reipl_fops = {
.owner = THIS_MODULE,
.write = zcore_reipl_write,
.open = zcore_reipl_open,
.release = zcore_reipl_release,
};
static void __init set_s390_lc_mask(union save_area *map)
{
memset(&map->s390.ext_save, 0xff, sizeof(map->s390.ext_save));
memset(&map->s390.timer, 0xff, sizeof(map->s390.timer));
memset(&map->s390.clk_cmp, 0xff, sizeof(map->s390.clk_cmp));
memset(&map->s390.psw, 0xff, sizeof(map->s390.psw));
memset(&map->s390.pref_reg, 0xff, sizeof(map->s390.pref_reg));
memset(&map->s390.acc_regs, 0xff, sizeof(map->s390.acc_regs));
memset(&map->s390.fp_regs, 0xff, sizeof(map->s390.fp_regs));
memset(&map->s390.gp_regs, 0xff, sizeof(map->s390.gp_regs));
memset(&map->s390.ctrl_regs, 0xff, sizeof(map->s390.ctrl_regs));
}
static void __init set_s390x_lc_mask(union save_area *map)
{
memset(&map->s390x.fp_regs, 0xff, sizeof(map->s390x.fp_regs));
memset(&map->s390x.gp_regs, 0xff, sizeof(map->s390x.gp_regs));
memset(&map->s390x.psw, 0xff, sizeof(map->s390x.psw));
memset(&map->s390x.pref_reg, 0xff, sizeof(map->s390x.pref_reg));
memset(&map->s390x.fp_ctrl_reg, 0xff, sizeof(map->s390x.fp_ctrl_reg));
memset(&map->s390x.tod_reg, 0xff, sizeof(map->s390x.tod_reg));
memset(&map->s390x.timer, 0xff, sizeof(map->s390x.timer));
memset(&map->s390x.clk_cmp, 0xff, sizeof(map->s390x.clk_cmp));
memset(&map->s390x.acc_regs, 0xff, sizeof(map->s390x.acc_regs));
memset(&map->s390x.ctrl_regs, 0xff, sizeof(map->s390x.ctrl_regs));
}
/*
* Initialize dump globals for a given architecture
*/
static int __init sys_info_init(enum arch_id arch)
{
int rc;
switch (arch) {
case ARCH_S390X:
pr_alert("DETECTED 'S390X (64 bit) OS'\n");
sys_info.sa_base = SAVE_AREA_BASE_S390X;
sys_info.sa_size = sizeof(struct save_area_s390x);
set_s390x_lc_mask(&sys_info.lc_mask);
break;
case ARCH_S390:
pr_alert("DETECTED 'S390 (32 bit) OS'\n");
sys_info.sa_base = SAVE_AREA_BASE_S390;
sys_info.sa_size = sizeof(struct save_area_s390);
set_s390_lc_mask(&sys_info.lc_mask);
break;
default:
pr_alert("0x%x is an unknown architecture.\n",arch);
return -EINVAL;
}
sys_info.arch = arch;
rc = init_cpu_info(arch);
if (rc)
return rc;
sys_info.mem_size = real_memory_size;
return 0;
}
static int __init check_sdias(void)
{
int rc, act_hsa_size;
rc = sclp_sdias_blk_count();
if (rc < 0) {
TRACE("Could not determine HSA size\n");
return rc;
}
act_hsa_size = (rc - 1) * PAGE_SIZE;
if (act_hsa_size < ZFCPDUMP_HSA_SIZE) {
TRACE("HSA size too small: %i\n", act_hsa_size);
return -EINVAL;
}
return 0;
}
static int __init get_mem_size(unsigned long *mem)
{
int i;
struct mem_chunk *chunk_array;
chunk_array = kzalloc(MEMORY_CHUNKS * sizeof(struct mem_chunk),
GFP_KERNEL);
if (!chunk_array)
return -ENOMEM;
detect_memory_layout(chunk_array);
for (i = 0; i < MEMORY_CHUNKS; i++) {
if (chunk_array[i].size == 0)
break;
*mem += chunk_array[i].size;
}
kfree(chunk_array);
return 0;
}
static int __init zcore_header_init(int arch, struct zcore_header *hdr)
{
int rc;
unsigned long memory = 0;
if (arch == ARCH_S390X)
hdr->arch_id = DUMP_ARCH_S390X;
else
hdr->arch_id = DUMP_ARCH_S390;
rc = get_mem_size(&memory);
if (rc)
return rc;
hdr->mem_size = memory;
hdr->rmem_size = memory;
hdr->mem_end = sys_info.mem_size;
hdr->num_pages = memory / PAGE_SIZE;
hdr->tod = get_clock();
get_cpu_id(&hdr->cpu_id);
return 0;
}
/*
* Provide IPL parameter information block from either HSA or memory
* for future reipl
*/
static int __init zcore_reipl_init(void)
{
struct ipib_info ipib_info;
int rc;
rc = memcpy_hsa_kernel(&ipib_info, __LC_DUMP_REIPL, sizeof(ipib_info));
if (rc)
return rc;
if (ipib_info.ipib == 0)
return 0;
ipl_block = (void *) __get_free_page(GFP_KERNEL);
if (!ipl_block)
return -ENOMEM;
if (ipib_info.ipib < ZFCPDUMP_HSA_SIZE)
rc = memcpy_hsa_kernel(ipl_block, ipib_info.ipib, PAGE_SIZE);
else
rc = memcpy_real(ipl_block, ipib_info.ipib, PAGE_SIZE);
if (rc) {
free_page((unsigned long) ipl_block);
return rc;
}
if (csum_partial(ipl_block, ipl_block->hdr.len, 0) !=
ipib_info.checksum) {
TRACE("Checksum does not match\n");
free_page((unsigned long) ipl_block);
ipl_block = NULL;
}
return 0;
}
static int __init zcore_init(void)
{
unsigned char arch;
int rc;
if (ipl_info.type != IPL_TYPE_FCP_DUMP)
return -ENODATA;
zcore_dbf = debug_register("zcore", 4, 1, 4 * sizeof(long));
debug_register_view(zcore_dbf, &debug_sprintf_view);
debug_set_level(zcore_dbf, 6);
TRACE("devno: %x\n", ipl_info.data.fcp.dev_id.devno);
TRACE("wwpn: %llx\n", (unsigned long long) ipl_info.data.fcp.wwpn);
TRACE("lun: %llx\n", (unsigned long long) ipl_info.data.fcp.lun);
rc = sclp_sdias_init();
if (rc)
goto fail;
rc = check_sdias();
if (rc)
goto fail;
rc = memcpy_hsa_kernel(&arch, __LC_AR_MODE_ID, 1);
if (rc)
goto fail;
#ifndef __s390x__
if (arch == ARCH_S390X) {
pr_alert("The 32-bit dump tool cannot be used for a "
"64-bit system\n");
rc = -EINVAL;
goto fail;
}
#endif
rc = sys_info_init(arch);
if (rc)
goto fail;
rc = zcore_header_init(arch, &zcore_header);
if (rc)
goto fail;
rc = zcore_reipl_init();
if (rc)
goto fail;
zcore_dir = debugfs_create_dir("zcore" , NULL);
if (!zcore_dir) {
rc = -ENOMEM;
goto fail;
}
zcore_file = debugfs_create_file("mem", S_IRUSR, zcore_dir, NULL,
&zcore_fops);
if (!zcore_file) {
rc = -ENOMEM;
goto fail_dir;
}
zcore_memmap_file = debugfs_create_file("memmap", S_IRUSR, zcore_dir,
NULL, &zcore_memmap_fops);
if (!zcore_memmap_file) {
rc = -ENOMEM;
goto fail_file;
}
zcore_reipl_file = debugfs_create_file("reipl", S_IRUSR, zcore_dir,
NULL, &zcore_reipl_fops);
if (!zcore_reipl_file) {
rc = -ENOMEM;
goto fail_memmap_file;
}
hsa_available = 1;
return 0;
fail_memmap_file:
debugfs_remove(zcore_memmap_file);
fail_file:
debugfs_remove(zcore_file);
fail_dir:
debugfs_remove(zcore_dir);
fail:
diag308(DIAG308_REL_HSA, NULL);
return rc;
}
static void __exit zcore_exit(void)
{
debug_unregister(zcore_dbf);
sclp_sdias_exit();
free_page((unsigned long) ipl_block);
debugfs_remove(zcore_reipl_file);
debugfs_remove(zcore_memmap_file);
debugfs_remove(zcore_file);
debugfs_remove(zcore_dir);
diag308(DIAG308_REL_HSA, NULL);
}
MODULE_AUTHOR("Copyright IBM Corp. 2003,2008");
MODULE_DESCRIPTION("zcore module for zfcpdump support");
MODULE_LICENSE("GPL");
subsys_initcall(zcore_init);
module_exit(zcore_exit);