Merge with master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6.git

6 files changed, 259 insertions, 192 deletions

diff --git a/arch/s390/kernel/compat_ioctl.c b/arch/s390/kernel/compat_ioctl.c
index 96571ff7115d..03d03c6d3cbb 100644
--- a/arch/s390/kernel/compat_ioctl.c
+++ b/arch/s390/kernel/compat_ioctl.c
@@ -16,6 +16,7 @@
 #define CODE
 #include "../../../fs/compat_ioctl.c"
 #include <asm/dasd.h>
+#include <asm/cmb.h>
 #include <asm/tape390.h>
 
 static int do_ioctl32_pointer(unsigned int fd, unsigned int cmd,
@@ -58,7 +59,11 @@ COMPATIBLE_IOCTL(BIODASDPRRD)
 COMPATIBLE_IOCTL(BIODASDPSRD)
 COMPATIBLE_IOCTL(BIODASDGATTR)
 COMPATIBLE_IOCTL(BIODASDSATTR)
-
+#if defined(CONFIG_DASD_CMB) || defined(CONFIG_DASD_CMB_MODULE)
+COMPATIBLE_IOCTL(BIODASDCMFENABLE)
+COMPATIBLE_IOCTL(BIODASDCMFDISABLE)
+COMPATIBLE_IOCTL(BIODASDREADALLCMB)
+#endif
 #endif
 
 #if defined(CONFIG_S390_TAPE) || defined(CONFIG_S390_TAPE_MODULE)
diff --git a/arch/s390/kernel/ptrace.c b/arch/s390/kernel/ptrace.c
index 2d546c67f7c3..26889366929a 100644
--- a/arch/s390/kernel/ptrace.c
+++ b/arch/s390/kernel/ptrace.c
@@ -32,6 +32,7 @@
 #include <linux/user.h>
 #include <linux/security.h>
 #include <linux/audit.h>
+#include <linux/signal.h>
 
 #include <asm/segment.h>
 #include <asm/page.h>
@@ -609,7 +610,7 @@ do_ptrace(struct task_struct *child, long request, long addr, long data)
                 /* continue and stop at next (return from) syscall */
         case PTRACE_CONT:
                 /* restart after signal. */
-                if ((unsigned long) data >= _NSIG)
+                if (!valid_signal(data))
                         return -EIO;
                 if (request == PTRACE_SYSCALL)
                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
@@ -637,7 +638,7 @@ do_ptrace(struct task_struct *child, long request, long addr, long data)
 
         case PTRACE_SINGLESTEP:
                 /* set the trap flag. */
-                if ((unsigned long) data >= _NSIG)
+                if (!valid_signal(data))
                         return -EIO;
                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
                 child->exit_code = data;
diff --git a/arch/s390/kernel/s390_ksyms.c b/arch/s390/kernel/s390_ksyms.c
index 11fd6d556d8f..bee654abb6d3 100644
--- a/arch/s390/kernel/s390_ksyms.c
+++ b/arch/s390/kernel/s390_ksyms.c
@@ -34,7 +34,6 @@ EXPORT_SYMBOL(__clear_user_asm);
 EXPORT_SYMBOL(__strncpy_from_user_asm);
 EXPORT_SYMBOL(__strnlen_user_asm);
 EXPORT_SYMBOL(diag10);
-EXPORT_SYMBOL(default_storage_key);
 
 /*
  * semaphore ops
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index c879c40aa7a5..df83215beac3 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -44,6 +44,8 @@
 #include <asm/cpcmd.h>
 #include <asm/lowcore.h>
 #include <asm/irq.h>
+#include <asm/page.h>
+#include <asm/ptrace.h>
 
 /*
  * Machine setup..
@@ -53,13 +55,14 @@ unsigned int console_devno = -1;
 unsigned int console_irq = -1;
 unsigned long memory_size = 0;
 unsigned long machine_flags = 0;
-unsigned int default_storage_key = 0;
 struct {
         unsigned long addr, size, type;
 } memory_chunk[MEMORY_CHUNKS] = { { 0 } };
 #define CHUNK_READ_WRITE 0
 #define CHUNK_READ_ONLY 1
 volatile int __cpu_logical_map[NR_CPUS]; /* logical cpu to cpu address */
+unsigned long __initdata zholes_size[MAX_NR_ZONES];
+static unsigned long __initdata memory_end;
 
 /*
  * Setup options
@@ -78,11 +81,15 @@ static char command_line[COMMAND_LINE_SIZE] = { 0, };
 
 static struct resource code_resource = {
         .name  = "Kernel code",
+        .start = (unsigned long) &_text,
+        .end = (unsigned long) &_etext - 1,
         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
 };
 
 static struct resource data_resource = {
         .name = "Kernel data",
+        .start = (unsigned long) &_etext,
+        .end = (unsigned long) &_edata - 1,
         .flags = IORESOURCE_BUSY | IORESOURCE_MEM,
 };
 
@@ -310,90 +317,50 @@ void machine_power_off(void)
 
 EXPORT_SYMBOL(machine_power_off);
 
-/*
- * Setup function called from init/main.c just after the banner
- * was printed.
- */
-extern char _pstart, _pend, _stext;
+static void __init
+add_memory_hole(unsigned long start, unsigned long end)
+{
+        unsigned long dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
+
+        if (end <= dma_pfn)
+                zholes_size[ZONE_DMA] += end - start + 1;
+        else if (start > dma_pfn)
+                zholes_size[ZONE_NORMAL] += end - start + 1;
+        else {
+                zholes_size[ZONE_DMA] += dma_pfn - start + 1;
+                zholes_size[ZONE_NORMAL] += end - dma_pfn;
+        }
+}
 
-void __init setup_arch(char **cmdline_p)
+static void __init
+parse_cmdline_early(char **cmdline_p)
 {
-        unsigned long bootmap_size;
-        unsigned long memory_start, memory_end;
-        char c = ' ', cn, *to = command_line, *from = COMMAND_LINE;
-        unsigned long start_pfn, end_pfn;
-        static unsigned int smptrap=0;
-        unsigned long delay = 0;
-        struct _lowcore *lc;
-        int i;
+        char c = ' ', cn, *to = command_line, *from = COMMAND_LINE;
+        unsigned long delay = 0;
 
-        if (smptrap)
-                return;
-        smptrap=1;
+        /* Save unparsed command line copy for /proc/cmdline */
+        memcpy(saved_command_line, COMMAND_LINE, COMMAND_LINE_SIZE);
+        saved_command_line[COMMAND_LINE_SIZE-1] = '\0';
 
-        /*
-         * print what head.S has found out about the machine 
-         */
-#ifndef CONFIG_ARCH_S390X
-        printk((MACHINE_IS_VM) ?
-               "We are running under VM (31 bit mode)\n" :
-               "We are running native (31 bit mode)\n");
-        printk((MACHINE_HAS_IEEE) ?
-               "This machine has an IEEE fpu\n" :
-               "This machine has no IEEE fpu\n");
-#else /* CONFIG_ARCH_S390X */
-        printk((MACHINE_IS_VM) ?
-               "We are running under VM (64 bit mode)\n" :
-               "We are running native (64 bit mode)\n");
-#endif /* CONFIG_ARCH_S390X */
-
-        ROOT_DEV = Root_RAM0;
-        memory_start = (unsigned long) &_end;    /* fixit if use $CODELO etc*/
-#ifndef CONFIG_ARCH_S390X
-        memory_end = memory_size & ~0x400000UL;  /* align memory end to 4MB */
-        /*
-         * We need some free virtual space to be able to do vmalloc.
-         * On a machine with 2GB memory we make sure that we have at
-         * least 128 MB free space for vmalloc.
-         */
-        if (memory_end > 1920*1024*1024)
-                memory_end = 1920*1024*1024;
-#else /* CONFIG_ARCH_S390X */
-        memory_end = memory_size & ~0x200000UL;  /* detected in head.s */
-#endif /* CONFIG_ARCH_S390X */
-        init_mm.start_code = PAGE_OFFSET;
-        init_mm.end_code = (unsigned long) &_etext;
-        init_mm.end_data = (unsigned long) &_edata;
-        init_mm.brk = (unsigned long) &_end;
-
-        code_resource.start = (unsigned long) &_text;
-        code_resource.end = (unsigned long) &_etext - 1;
-        data_resource.start = (unsigned long) &_etext;
-        data_resource.end = (unsigned long) &_edata - 1;
-
-        /* Save unparsed command line copy for /proc/cmdline */
-        memcpy(saved_command_line, COMMAND_LINE, COMMAND_LINE_SIZE);
-        saved_command_line[COMMAND_LINE_SIZE-1] = '\0';
-
-        for (;;) {
-                /*
-                 * "mem=XXX[kKmM]" sets memsize 
-                 */
-                if (c == ' ' && strncmp(from, "mem=", 4) == 0) {
-                        memory_end = simple_strtoul(from+4, &from, 0);
-                        if ( *from == 'K' || *from == 'k' ) {
-                                memory_end = memory_end << 10;
-                                from++;
-                        } else if ( *from == 'M' || *from == 'm' ) {
-                                memory_end = memory_end << 20;
-                                from++;
-                        }
-                }
-                /*
-                 * "ipldelay=XXX[sm]" sets ipl delay in seconds or minutes
-                 */
-                if (c == ' ' && strncmp(from, "ipldelay=", 9) == 0) {
-                        delay = simple_strtoul(from+9, &from, 0);
+        for (;;) {
+                /*
+                 * "mem=XXX[kKmM]" sets memsize
+                 */
+                if (c == ' ' && strncmp(from, "mem=", 4) == 0) {
+                        memory_end = simple_strtoul(from+4, &from, 0);
+                        if ( *from == 'K' || *from == 'k' ) {
+                                memory_end = memory_end << 10;
+                                from++;
+                        } else if ( *from == 'M' || *from == 'm' ) {
+                                memory_end = memory_end << 20;
+                                from++;
+                        }
+                }
+                /*
+                 * "ipldelay=XXX[sm]" sets ipl delay in seconds or minutes
+                 */
+                if (c == ' ' && strncmp(from, "ipldelay=", 9) == 0) {
+                        delay = simple_strtoul(from+9, &from, 0);
                         if (*from == 's' || *from == 'S') {
                                 delay = delay*1000000;
                                 from++;
@@ -403,24 +370,110 @@ void __init setup_arch(char **cmdline_p)
                         }
                         /* now wait for the requested amount of time */
                         udelay(delay);
-                }
-                cn = *(from++);
-                if (!cn)
-                        break;
-                if (cn == '\n')
-                        cn = ' ';  /* replace newlines with space */
+                }
+                cn = *(from++);
+                if (!cn)
+                        break;
+                if (cn == '\n')
+                        cn = ' ';  /* replace newlines with space */
                 if (cn == 0x0d)
                         cn = ' ';  /* replace 0x0d with space */
-                if (cn == ' ' && c == ' ')
-                        continue;  /* remove additional spaces */
-                c = cn;
-                if (to - command_line >= COMMAND_LINE_SIZE)
-                        break;
-                *(to++) = c;
-        }
-        if (c == ' ' && to > command_line) to--;
-        *to = '\0';
-        *cmdline_p = command_line;
+                if (cn == ' ' && c == ' ')
+                        continue;  /* remove additional spaces */
+                c = cn;
+                if (to - command_line >= COMMAND_LINE_SIZE)
+                        break;
+                *(to++) = c;
+        }
+        if (c == ' ' && to > command_line) to--;
+        *to = '\0';
+        *cmdline_p = command_line;
+}
+
+static void __init
+setup_lowcore(void)
+{
+        struct _lowcore *lc;
+        int lc_pages;
+
+        /*
+         * Setup lowcore for boot cpu
+         */
+        lc_pages = sizeof(void *) == 8 ? 2 : 1;
+        lc = (struct _lowcore *)
+                __alloc_bootmem(lc_pages * PAGE_SIZE, lc_pages * PAGE_SIZE, 0);
+        memset(lc, 0, lc_pages * PAGE_SIZE);
+        lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
+        lc->restart_psw.addr =
+                PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
+        lc->external_new_psw.mask = PSW_KERNEL_BITS;
+        lc->external_new_psw.addr =
+                PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
+        lc->svc_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_IO | PSW_MASK_EXT;
+        lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
+        lc->program_new_psw.mask = PSW_KERNEL_BITS;
+        lc->program_new_psw.addr =
+                PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
+        lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
+        lc->mcck_new_psw.addr =
+                PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
+        lc->io_new_psw.mask = PSW_KERNEL_BITS;
+        lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
+        lc->ipl_device = S390_lowcore.ipl_device;
+        lc->jiffy_timer = -1LL;
+        lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
+        lc->async_stack = (unsigned long)
+                __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
+#ifdef CONFIG_CHECK_STACK
+        lc->panic_stack = (unsigned long)
+                __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
+#endif
+        lc->current_task = (unsigned long) init_thread_union.thread_info.task;
+        lc->thread_info = (unsigned long) &init_thread_union;
+#ifdef CONFIG_ARCH_S390X
+        if (MACHINE_HAS_DIAG44)
+                lc->diag44_opcode = 0x83000044;
+        else
+                lc->diag44_opcode = 0x07000700;
+#endif /* CONFIG_ARCH_S390X */
+        set_prefix((u32)(unsigned long) lc);
+}
+
+static void __init
+setup_resources(void)
+{
+        struct resource *res;
+        int i;
+
+        for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
+                res = alloc_bootmem_low(sizeof(struct resource));
+                res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
+                switch (memory_chunk[i].type) {
+                case CHUNK_READ_WRITE:
+                        res->name = "System RAM";
+                        break;
+                case CHUNK_READ_ONLY:
+                        res->name = "System ROM";
+                        res->flags |= IORESOURCE_READONLY;
+                        break;
+                default:
+                        res->name = "reserved";
+                }
+                res->start = memory_chunk[i].addr;
+                res->end = memory_chunk[i].addr +  memory_chunk[i].size - 1;
+                request_resource(&iomem_resource, res);
+                request_resource(res, &code_resource);
+                request_resource(res, &data_resource);
+        }
+}
+
+static void __init
+setup_memory(void)
+{
+        unsigned long bootmap_size;
+        unsigned long start_pfn, end_pfn, init_pfn;
+        unsigned long last_rw_end;
+        int i;
 
         /*
          * partially used pages are not usable - thus
@@ -429,6 +482,10 @@ void __init setup_arch(char **cmdline_p)
         start_pfn = (__pa(&_end) + PAGE_SIZE - 1) >> PAGE_SHIFT;
         end_pfn = max_pfn = memory_end >> PAGE_SHIFT;
 
+        /* Initialize storage key for kernel pages */
+        for (init_pfn = 0 ; init_pfn < start_pfn; init_pfn++)
+                page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
+
         /*
          * Initialize the boot-time allocator (with low memory only):
          */
@@ -437,7 +494,9 @@ void __init setup_arch(char **cmdline_p)
         /*
          * Register RAM areas with the bootmem allocator.
          */
-        for (i = 0; i < 16 && memory_chunk[i].size > 0; i++) {
+        last_rw_end = start_pfn;
+
+        for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
                 unsigned long start_chunk, end_chunk;
 
                 if (memory_chunk[i].type != CHUNK_READ_WRITE)
@@ -450,102 +509,98 @@ void __init setup_arch(char **cmdline_p)
                         start_chunk = start_pfn;
                 if (end_chunk > end_pfn)
                         end_chunk = end_pfn;
-                if (start_chunk < end_chunk)
+                if (start_chunk < end_chunk) {
+                        /* Initialize storage key for RAM pages */
+                        for (init_pfn = start_chunk ; init_pfn < end_chunk;
+                             init_pfn++)
+                                page_set_storage_key(init_pfn << PAGE_SHIFT,
+                                                     PAGE_DEFAULT_KEY);
                         free_bootmem(start_chunk << PAGE_SHIFT,
                                      (end_chunk - start_chunk) << PAGE_SHIFT);
+                        if (last_rw_end < start_chunk)
+                                add_memory_hole(last_rw_end, start_chunk - 1);
+                        last_rw_end = end_chunk;
+                }
         }
 
-        /*
-         * Reserve the bootmem bitmap itself as well. We do this in two
-         * steps (first step was init_bootmem()) because this catches
-         * the (very unlikely) case of us accidentally initializing the
-         * bootmem allocator with an invalid RAM area.
-         */
-        reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size);
+        psw_set_key(PAGE_DEFAULT_KEY);
+
+        if (last_rw_end < end_pfn - 1)
+                add_memory_hole(last_rw_end, end_pfn - 1);
+
+        /*
+         * Reserve the bootmem bitmap itself as well. We do this in two
+         * steps (first step was init_bootmem()) because this catches
+         * the (very unlikely) case of us accidentally initializing the
+         * bootmem allocator with an invalid RAM area.
+         */
+        reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size);
 
 #ifdef CONFIG_BLK_DEV_INITRD
-        if (INITRD_START) {
+        if (INITRD_START) {
                 if (INITRD_START + INITRD_SIZE <= memory_end) {
                         reserve_bootmem(INITRD_START, INITRD_SIZE);
                         initrd_start = INITRD_START;
                         initrd_end = initrd_start + INITRD_SIZE;
                 } else {
-                        printk("initrd extends beyond end of memory "
-                               "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
-                               initrd_start + INITRD_SIZE, memory_end);
-                        initrd_start = initrd_end = 0;
+                        printk("initrd extends beyond end of memory "
+                               "(0x%08lx > 0x%08lx)\ndisabling initrd\n",
+                               initrd_start + INITRD_SIZE, memory_end);
+                        initrd_start = initrd_end = 0;
                 }
-        }
+        }
 #endif
+}
 
-        for (i = 0; i < 16 && memory_chunk[i].size > 0; i++) {
-                struct resource *res;
-
-                res = alloc_bootmem_low(sizeof(struct resource));
-                res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
-
-                switch (memory_chunk[i].type) {
-                case CHUNK_READ_WRITE:
-                        res->name = "System RAM";
-                        break;
-                case CHUNK_READ_ONLY:
-                        res->name = "System ROM";
-                        res->flags |= IORESOURCE_READONLY;
-                        break;
-                default:
-                        res->name = "reserved";
-                }
-                res->start = memory_chunk[i].addr;
-                res->end = memory_chunk[i].addr +  memory_chunk[i].size - 1;
-                request_resource(&iomem_resource, res);
-                request_resource(res, &code_resource);
-                request_resource(res, &data_resource);
-        }
+/*
+ * Setup function called from init/main.c just after the banner
+ * was printed.
+ */
 
+void __init
+setup_arch(char **cmdline_p)
+{
         /*
-         * Setup lowcore for boot cpu
+         * print what head.S has found out about the machine
          */
 #ifndef CONFIG_ARCH_S390X
-        lc = (struct _lowcore *) __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0);
-        memset(lc, 0, PAGE_SIZE);
+        printk((MACHINE_IS_VM) ?
+               "We are running under VM (31 bit mode)\n" :
+               "We are running native (31 bit mode)\n");
+        printk((MACHINE_HAS_IEEE) ?
+               "This machine has an IEEE fpu\n" :
+               "This machine has no IEEE fpu\n");
 #else /* CONFIG_ARCH_S390X */
-        lc = (struct _lowcore *) __alloc_bootmem(2*PAGE_SIZE, 2*PAGE_SIZE, 0);
-        memset(lc, 0, 2*PAGE_SIZE);
+        printk((MACHINE_IS_VM) ?
+               "We are running under VM (64 bit mode)\n" :
+               "We are running native (64 bit mode)\n");
 #endif /* CONFIG_ARCH_S390X */
-        lc->restart_psw.mask = PSW_BASE_BITS;
-        lc->restart_psw.addr =
-                PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
-        lc->external_new_psw.mask = PSW_KERNEL_BITS;
-        lc->external_new_psw.addr =
-                PSW_ADDR_AMODE | (unsigned long) ext_int_handler;
-        lc->svc_new_psw.mask = PSW_KERNEL_BITS | PSW_MASK_IO | PSW_MASK_EXT;
-        lc->svc_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) system_call;
-        lc->program_new_psw.mask = PSW_KERNEL_BITS;
-        lc->program_new_psw.addr =
-                PSW_ADDR_AMODE | (unsigned long)pgm_check_handler;
-        lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
-        lc->mcck_new_psw.addr =
-                PSW_ADDR_AMODE | (unsigned long) mcck_int_handler;
-        lc->io_new_psw.mask = PSW_KERNEL_BITS;
-        lc->io_new_psw.addr = PSW_ADDR_AMODE | (unsigned long) io_int_handler;
-        lc->ipl_device = S390_lowcore.ipl_device;
-        lc->jiffy_timer = -1LL;
-        lc->kernel_stack = ((unsigned long) &init_thread_union) + THREAD_SIZE;
-        lc->async_stack = (unsigned long)
-                __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0) + ASYNC_SIZE;
-#ifdef CONFIG_CHECK_STACK
-        lc->panic_stack = (unsigned long)
-                __alloc_bootmem(PAGE_SIZE, PAGE_SIZE, 0) + PAGE_SIZE;
-#endif
-        lc->current_task = (unsigned long) init_thread_union.thread_info.task;
-        lc->thread_info = (unsigned long) &init_thread_union;
-#ifdef CONFIG_ARCH_S390X
-        if (MACHINE_HAS_DIAG44)
-                lc->diag44_opcode = 0x83000044;
-        else
-                lc->diag44_opcode = 0x07000700;
+
+        ROOT_DEV = Root_RAM0;
+#ifndef CONFIG_ARCH_S390X
+        memory_end = memory_size & ~0x400000UL;  /* align memory end to 4MB */
+        /*
+         * We need some free virtual space to be able to do vmalloc.
+         * On a machine with 2GB memory we make sure that we have at
+         * least 128 MB free space for vmalloc.
+         */
+        if (memory_end > 1920*1024*1024)
+                memory_end = 1920*1024*1024;
+#else /* CONFIG_ARCH_S390X */
+        memory_end = memory_size & ~0x200000UL;  /* detected in head.s */
 #endif /* CONFIG_ARCH_S390X */
-        set_prefix((u32)(unsigned long) lc);
+
+        init_mm.start_code = PAGE_OFFSET;
+        init_mm.end_code = (unsigned long) &_etext;
+        init_mm.end_data = (unsigned long) &_edata;
+        init_mm.brk = (unsigned long) &_end;
+
+        parse_cmdline_early(cmdline_p);
+
+        setup_memory();
+        setup_resources();
+        setup_lowcore();
+
         cpu_init();
         __cpu_logical_map[0] = S390_lowcore.cpu_data.cpu_addr;
 
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 061e81138dc2..8ca485676780 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -244,7 +244,7 @@ int sysctl_hz_timer = 1;
  */
 static inline void stop_hz_timer(void)
 {
-        __u64 timer;
+        __u64 timer, todval;
 
         if (sysctl_hz_timer != 0)
                 return;
@@ -265,8 +265,14 @@ static inline void stop_hz_timer(void)
          * for the next event.
          */
         timer = (__u64) (next_timer_interrupt() - jiffies) + jiffies_64;
-        timer = jiffies_timer_cc + timer * CLK_TICKS_PER_JIFFY;
-        asm volatile ("SCKC %0" : : "m" (timer));
+        todval = -1ULL;
+        /* Be careful about overflows. */
+        if (timer < (-1ULL / CLK_TICKS_PER_JIFFY)) {
+                timer = jiffies_timer_cc + timer * CLK_TICKS_PER_JIFFY;
+                if (timer >= jiffies_timer_cc)
+                        todval = timer;
+        }
+        asm volatile ("SCKC %0" : : "m" (todval));
 }
 
 /*
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index bb6cf02418a2..fa0726507b3d 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -122,12 +122,17 @@ static void start_cpu_timer(void)
         struct vtimer_queue *vt_list;
 
         vt_list = &per_cpu(virt_cpu_timer, smp_processor_id());
-        set_vtimer(vt_list->idle);
+
+        /* CPU timer interrupt is pending, don't reprogramm it */
+        if (vt_list->idle & 1LL<<63)
+                return;
+
+        if (!list_empty(&vt_list->list))
+                set_vtimer(vt_list->idle);
 }
 
 static void stop_cpu_timer(void)
 {
-        __u64 done;
         struct vtimer_queue *vt_list;
 
         vt_list = &per_cpu(virt_cpu_timer, smp_processor_id());
@@ -138,21 +143,17 @@ static void stop_cpu_timer(void)
                 goto fire;
         }
 
-        /* store progress */
-        asm volatile ("STPT %0" : "=m" (done));
+        /* store the actual expire value */
+        asm volatile ("STPT %0" : "=m" (vt_list->idle));
 
         /*
-         * If done is negative we do not stop the CPU timer
-         * because we will get instantly an interrupt that
-         * will start the CPU timer again.
+         * If the CPU timer is negative we don't reprogramm
+         * it because we will get instantly an interrupt.
          */
-        if (done & 1LL<<63)
+        if (vt_list->idle & 1LL<<63)
                 return;
-        else
-                vt_list->offset += vt_list->to_expire - done;
 
-        /* save the actual expire value */
-        vt_list->idle = done;
+        vt_list->offset += vt_list->to_expire - vt_list->idle;
 
         /*
          * We cannot halt the CPU timer, we just write a value that