/* Reads a page from the oldmem device from given offset. */
static ssize_t read_from_oldmem(char *buf, size_t count,
u64 *ppos, int userbuf)
{
unsigned long pfn, offset;
size_t nr_bytes;
ssize_t read = 0, tmp;
if (!count)
return 0;
offset = (unsigned long)(*ppos % PAGE_SIZE);
pfn = (unsigned long)(*ppos / PAGE_SIZE);
if (pfn > saved_max_pfn)
return -EINVAL;
do {
if (count > (PAGE_SIZE - offset))
nr_bytes = PAGE_SIZE - offset;
else
nr_bytes = count;
tmp = copy_oldmem_page(pfn, buf, nr_bytes, offset, userbuf);
if (tmp < 0)
return tmp;
*ppos += nr_bytes;
count -= nr_bytes;
buf += nr_bytes;
read += nr_bytes;
++pfn;
offset = 0;
} while (count);
return read;
}
/* Reads a page from the oldmem device from given offset. */
static ssize_t read_from_oldmem(char *buf, size_t count,
u64 *ppos, int userbuf)
{
unsigned long pfn, offset;
size_t nr_bytes;
ssize_t read = 0, tmp;
if (!count)
return 0;
offset = (unsigned long)(*ppos % PAGE_SIZE);
pfn = (unsigned long)(*ppos / PAGE_SIZE);
do {
if (count > (PAGE_SIZE - offset))
nr_bytes = PAGE_SIZE - offset;
else
nr_bytes = count;
/* If pfn is not ram, return zeros for sparse dump files */
if (pfn_is_ram(pfn) == 0) {
if (userbuf) {
if (clear_user((char __force_user *)buf, nr_bytes))
return -EFAULT;
} else
memset(buf, 0, nr_bytes);
} else {
tmp = copy_oldmem_page(pfn, buf, nr_bytes,
offset, userbuf);
if (tmp < 0)
return tmp;
}
*ppos += nr_bytes;
count -= nr_bytes;
buf += nr_bytes;
read += nr_bytes;
++pfn;
offset = 0;
} while (count);
return read;
}
static void __init smp_detect_cpus(void)
{
unsigned int cpu, c_cpus, s_cpus;
struct sclp_cpu_info *info;
u16 boot_cpu_addr, cpu_addr;
c_cpus = 1;
s_cpus = 0;
boot_cpu_addr = __cpu_logical_map[0];
info = kmalloc(sizeof(*info), GFP_KERNEL);
if (!info)
panic("smp_detect_cpus failed to allocate memory\n");
#ifdef CONFIG_CRASH_DUMP
if (OLDMEM_BASE && !is_kdump_kernel()) {
struct save_area *save_area;
save_area = kmalloc(sizeof(*save_area), GFP_KERNEL);
if (!save_area)
panic("could not allocate memory for save area\n");
copy_oldmem_page(1, (void *) save_area, sizeof(*save_area),
0x200, 0);
zfcpdump_save_areas[0] = save_area;
}
#endif
/* Use sigp detection algorithm if sclp doesn't work. */
if (sclp_get_cpu_info(info)) {
smp_use_sigp_detection = 1;
for (cpu = 0; cpu <= MAX_CPU_ADDRESS; cpu++) {
if (cpu == boot_cpu_addr)
continue;
if (!raw_cpu_stopped(cpu))
continue;
smp_get_save_area(c_cpus, cpu);
c_cpus++;
}
goto out;
}
if (info->has_cpu_type) {
for (cpu = 0; cpu < info->combined; cpu++) {
if (info->cpu[cpu].address == boot_cpu_addr) {
smp_cpu_type = info->cpu[cpu].type;
break;
}
}
}
for (cpu = 0; cpu < info->combined; cpu++) {
if (info->has_cpu_type && info->cpu[cpu].type != smp_cpu_type)
continue;
cpu_addr = info->cpu[cpu].address;
if (cpu_addr == boot_cpu_addr)
continue;
if (!raw_cpu_stopped(cpu_addr)) {
s_cpus++;
continue;
}
smp_get_save_area(c_cpus, cpu_addr);
c_cpus++;
}
out:
kfree(info);
pr_info("%d configured CPUs, %d standby CPUs\n", c_cpus, s_cpus);
get_online_cpus();
__smp_rescan_cpus();
put_online_cpus();
}
