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| author |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2007-02-05 21:18:19 +0100 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2007-02-05 21:18:19 +0100 |
| commit | d54853ef8cb17296ac7bce9c77430fb7c80532d0 (patch) | |
| tree | 649e14d532e17231225a042a7c9a3d9207ad91ee /drivers/s390/s390mach.c | |
| parent | [S390] noexec protection (diff) | |
| download | linux-dev-d54853ef8cb17296ac7bce9c77430fb7c80532d0.tar.xz linux-dev-d54853ef8cb17296ac7bce9c77430fb7c80532d0.zip | |
[S390] ETR support.
This patch adds support for clock synchronization to an external time
reference (ETR). The external time reference sends an oscillator
signal and a synchronization signal every 2^20 microseconds to keep
the TOD clocks of all connected servers in sync. For availability
two ETR units can be connected to a machine. If the clock deviates
for more than the sync-check tolerance all cpus get a machine check
that indicates that the clock is out of sync. For the lovely details
how to get the clock back in sync see the code below.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/s390mach.c')
| -rw-r--r-- | drivers/s390/s390mach.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/s390/s390mach.c b/drivers/s390/s390mach.c index 442d63470428..806bb1a921eb 100644 --- a/drivers/s390/s390mach.c +++ b/drivers/s390/s390mach.c @@ -15,7 +15,7 @@ #include <linux/time.h> #include <linux/device.h> #include <linux/kthread.h> - +#include <asm/etr.h> #include <asm/lowcore.h> #include <asm/cio.h> #include "cio/cio.h" @@ -466,6 +466,19 @@ s390_do_machine_check(struct pt_regs *regs) s390_handle_damage("unable to revalidate registers."); } + if (mci->cd) { + /* Timing facility damage */ + s390_handle_damage("TOD clock damaged"); + } + + if (mci->ed && mci->ec) { + /* External damage */ + if (S390_lowcore.external_damage_code & (1U << ED_ETR_SYNC)) + etr_sync_check(); + if (S390_lowcore.external_damage_code & (1U << ED_ETR_SWITCH)) + etr_switch_to_local(); + } + if (mci->se) /* Storage error uncorrected */ s390_handle_damage("received storage error uncorrected " @@ -504,7 +517,7 @@ static int machine_check_init(void) { init_MUTEX_LOCKED(&m_sem); - ctl_clear_bit(14, 25); /* disable external damage MCH */ + ctl_set_bit(14, 25); /* enable external damage MCH */ ctl_set_bit(14, 27); /* enable system recovery MCH */ #ifdef CONFIG_MACHCHK_WARNING ctl_set_bit(14, 24); /* enable warning MCH */ |