Merge tag 's390-5.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 fixes from Martin Schwidefsky:

 - Do not claim to run under z/VM if the hypervisor can not be
   identified

 - Fix crashes due to outdated ASCEs in CR1

 - Avoid a deadlock in regard to CPU hotplug

 - Really fix the vdso mapping issue for compat tasks

 - Avoid crash on restart due to an incorrect stack address

* tag 's390-5.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU
  s390/vdso: correct vdso mapping for compat tasks
  s390/smp: fix CPU hotplug deadlock with CPU rescan
  s390/mm: always force a load of the primary ASCE on context switch
  s390/early: improve machine detection

diff --git a/arch/s390/include/asm/mmu_context.h b/arch/s390/include/asm/mmu_context.h
index ccbb53e2202404b85aae86e883d3e64405d2d305..8d04e6f3f79649d460376f09217c9e8fe211a850 100644 (file)
--- a/arch/s390/include/asm/mmu_context.h
+++ b/arch/s390/include/asm/mmu_context.h
@@ -25,7 +25,7 @@ static inline int init_new_context(struct task_struct *tsk,
        atomic_set(&mm->context.flush_count, 0);
        mm->context.gmap_asce = 0;
        mm->context.flush_mm = 0;
-       mm->context.compat_mm = 0;
+       mm->context.compat_mm = test_thread_flag(TIF_31BIT);
 #ifdef CONFIG_PGSTE
        mm->context.alloc_pgste = page_table_allocate_pgste ||
                test_thread_flag(TIF_PGSTE) ||
@@ -90,8 +90,6 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 {
        int cpu = smp_processor_id();
 
-       if (prev == next)
-               return;
        S390_lowcore.user_asce = next->context.asce;
        cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
        /* Clear previous user-ASCE from CR1 and CR7 */
@@ -103,7 +101,8 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
                __ctl_load(S390_lowcore.vdso_asce, 7, 7);
                clear_cpu_flag(CIF_ASCE_SECONDARY);
        }
-       cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
+       if (prev != next)
+               cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
 }
 
 #define finish_arch_post_lock_switch finish_arch_post_lock_switch

diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index af5c2b3f706567f5f9927686ccfd210b50366221..a8c7789b246b49eb5a546360e4491eaf0f9eac7b 100644 (file)
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -63,10 +63,10 @@ static noinline __init void detect_machine_type(void)
        if (stsi(vmms, 3, 2, 2) || !vmms->count)
                return;
 
-       /* Running under KVM? If not we assume z/VM */
+       /* Detect known hypervisors */
        if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
                S390_lowcore.machine_flags |= MACHINE_FLAG_KVM;
-       else
+       else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
                S390_lowcore.machine_flags |= MACHINE_FLAG_VM;
 }
 

diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 72dd23ef771b6bf22f77e71df22a40e05fbee2d5..7ed90a75913572f752652d611a0cd5347279d8e2 100644 (file)
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -1006,6 +1006,8 @@ void __init setup_arch(char **cmdline_p)
                pr_info("Linux is running under KVM in 64-bit mode\n");
        else if (MACHINE_IS_LPAR)
                pr_info("Linux is running natively in 64-bit mode\n");
+       else
+               pr_info("Linux is running as a guest in 64-bit mode\n");
 
        /* Have one command line that is parsed and saved in /proc/cmdline */
        /* boot_command_line has been already set up in early.c */

diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index f82b3d3c36e2d5620e4b8e6b363936bcdf38d673..b198ece2aad63d70f58b2acde1c280ce5534cf7a 100644 (file)
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -381,8 +381,13 @@ void smp_call_online_cpu(void (*func)(void *), void *data)
  */
 void smp_call_ipl_cpu(void (*func)(void *), void *data)
 {
+       struct lowcore *lc = pcpu_devices->lowcore;
+
+       if (pcpu_devices[0].address == stap())
+               lc = &S390_lowcore;
+
        pcpu_delegate(&pcpu_devices[0], func, data,
-                     pcpu_devices->lowcore->nodat_stack);
+                     lc->nodat_stack);
 }
 
 int smp_find_processor_id(u16 address)
@@ -1166,7 +1171,11 @@ static ssize_t __ref rescan_store(struct device *dev,
 {
        int rc;
 
+       rc = lock_device_hotplug_sysfs();
+       if (rc)
+               return rc;
        rc = smp_rescan_cpus();
+       unlock_device_hotplug();
        return rc ? rc : count;
 }
 static DEVICE_ATTR_WO(rescan);

diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index ebe748a9f472fde63cfccd42921472233f6ea529..4ff354887db412a504bb432956c28b2ba6b8a936 100644 (file)
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -224,10 +224,9 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 
        vdso_pages = vdso64_pages;
 #ifdef CONFIG_COMPAT
-       if (is_compat_task()) {
+       mm->context.compat_mm = is_compat_task();
+       if (mm->context.compat_mm)
                vdso_pages = vdso32_pages;
-               mm->context.compat_mm = 1;
-       }
 #endif
        /*
         * vDSO has a problem and was disabled, just don't "enable" it for

diff --git a/drivers/s390/char/sclp_config.c b/drivers/s390/char/sclp_config.c
index 194ffd5c8580401a13eefb3f85e61fdba2d5e7e6..039b2074db7e5d39a88aeed516630e62dfc05e4e 100644 (file)
--- a/drivers/s390/char/sclp_config.c
+++ b/drivers/s390/char/sclp_config.c
@@ -60,7 +60,9 @@ static void sclp_cpu_capability_notify(struct work_struct *work)
 
 static void __ref sclp_cpu_change_notify(struct work_struct *work)
 {
+       lock_device_hotplug();
        smp_rescan_cpus();
+       unlock_device_hotplug();
 }
 
 static void sclp_conf_receiver_fn(struct evbuf_header *evbuf)