- 03 Nov, 2015 1 commit
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Martin Schwidefsky authored
git commit 155e839a "s390/kernel: dynamically allocate FP register save area" introduced a regression in regard to ptrace. If the vector register extension is not present or unused the ptrace peek of a floating pointer register return incorrect data and the ptrace poke to a floating pointer register overwrites the task structure starting at task->thread.fpu.fprs. Cc: stable@kernel.org # v4.3 Signed-off-by:
Martin Schwidefsky <schwidefsky@de.ibm.com>
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- 27 Oct, 2015 9 commits
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Sebastian Ott authored
device_ops.c should only contain functions that are called by ccw device drivers. Move the cio internal functions that handle unconditional reserve + release to device_pgid.c Acked-by:
Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by:
Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by:
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Sebastian Ott authored
device_ops.c should only contain functions that are called by ccw device drivers. Move the cio internal function ccw_device_call_handler to device_fsm.c where it's used. Remove some useless comments while at it. Acked-by:
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Heiko Carstens authored
Each per_cpu() invocation generates extra code. Since there are a lot of similiar calls in the topology code we can avoid a lot of them. Signed-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:
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Heiko Carstens authored
Change the flag fields within struct mcck_struct to simple bit fields to reduce the size of the structure which is used as percpu variable. Signed-off-by:
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Heiko Carstens authored
According to the architecture registers are validated and not revalidated. So change comments and functions names to match. Signed-off-by:
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Heiko Carstens authored
Remove all the casts to and from the machine check interruption code. This patch changes struct mci to a union, which contains an anonymous structure with the already known bits and in addition an unsigned long field, which contains the raw machine check interruption code. This allows to simply assign and decoce the interruption code value without the need for all those casts we had all the time. Signed-off-by:
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Heiko Carstens authored
s390_handle_damage() has character string parameter which was used as a pointer to verbose error message. The hope was (a lot of years ago) when analyzing dumps that register R2 would still contain the pointer and therefore it would be rather easy to tell what went wrong. However gcc optimizes the strings away since a long time. And even if it wouldn't it is necessary to have a close look at the machine check interruption code to tell what's wrong. So remove the pointless error strings. Signed-off-by:
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Heiko Carstens authored
The current disabled wait code stores register contents into their save areas, however it is (at least) missing the new vector registers. Given the fact that the whole exercise seems to be rather pointless simply don't save any registers anymore. In a "live" system it is always possible to inspect register contents, and in case of a dump the register contents will be stored by the dump mechanism. Signed-off-by:
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Heiko Carstens authored
With the removal of 31 bit code we can always assume that the epsw instruction is available. Therefore use the __extract_psw() function to disable and enable machine checks. Signed-off-by:
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- 16 Oct, 2015 1 commit
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Hendrik Brueckner authored
Split the API and FPU type definitions into separate header files similar to "x86/fpu: Rename fpu-internal.h to fpu/internal.h" (78f7f1e5). The new header files and their meaning are: asm/fpu/types.h: FPU related data types, needed for 'struct thread_struct' and 'struct task_struct'. asm/fpu/api.h: FPU related 'public' functions for other subsystems and device drivers. asm/fpu/internal.h: FPU internal functions mainly used to convert FPU register contents in signal handling. Signed-off-by:
Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by:
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- 15 Oct, 2015 1 commit
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Stefan Haberland authored
A summary unit check occurs when the lcu updates the PAV configuration e.g. base PAV assignment or PAV mode at all. This requires the reset of the drivers internal pavgroups. Therefore the alias devices are flushed and moved via a temporary list to the active_devices list where they are not associated with a pavgroup. In conjunction with updates to the base device the pavgroup may be removed since both base_list and alias_list are empty. Unfortunately during alias flush and move to the active_device list from alias_list the pavgroup pointer is not deleted in the device private structure. This leads to a list del_corruption if another lcu_update tries to move the device in the non existent pavgroup. Fix by removing the pavgroup pointer after the alias device was moved to the active_devices list. Signed-off-by:
Stefan Haberland <stefan.haberland@de.ibm.com> Signed-off-by:
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- 14 Oct, 2015 28 commits
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Christian Borntraeger authored
the kernel locks have aqcuire/release semantics. No operation done after the lock can be "moved" before the lock and no operation before the unlock can be moved after the unlock. But it is perfectly fine that memory accesses which happen code wise after unlock are performed within the critical section. On s390x, reads are in-order with other reads (PoP section "Storage-Operand Fetch References") and writes are in-order with other writes (PoP section "Storage-Operand Store References"). Writes are also in-order with reads to the same memory location (PoP section "Storage-Operand Store References"). To other CPUs (and the channel subsystem), reads additionally appear to be performed prior to reads or writes that happen after them in the conceptual sequence (PoP section "Relation between Operand Accesses"). So at least as observed by other CPUs and the channel subsystem, reads inside the critical sections will not happen after unlock (and writes are in-order anyway). That's exactly what we need for "RELEASE operations" (memory-barriers.txt): "It guarantees that all memory operations before the RELEASE operation will appear to happen before the RELEASE operation with respect to the other components of the system." Suggested-by:
Paolo Bonzini <pbonzini@redhat.com> Signed-off-by:
Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-By:
Sascha Silbe <silbe@linux.vnet.ibm.com> [cross-reading and lot of improvements for the patch description] Signed-off-by:
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Martin Schwidefsky authored
There is a system work queue system_long_wq for long running work. Use this work queue for the AP bus scan loop. Reviewd-by:
Ingo Tuchscherer <ingo.tuchscherer@linux.vnet.ibm.com> Signed-off-by:
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Martin Schwidefsky authored
Remove the code for really old crypt cards, PCICC and PCICA. These cards have been out of service for several years. Reviewd-by:
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Martin Schwidefsky authored
Replace the two fields 'unregistered' and 'reset' with a device state with 5 possible values. Introduce two events for the AP devices, device poll and device timeout. With the state machine it is easier to deal with device initialization and suspend/resume. Device polling is simpler as well, the arkane 'flags' passing is gone. Reviewd-by:
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Martin Schwidefsky authored
If a AP device is removed while messages are still pending, the requests are cancelled by calling the message receive function with an error pointer for the reply. The message type receive handler recognize this and create a fake hardware error TYPE82_RSP_CODE / REP82_ERROR_MACHINE_FAILURE. The message with the hardware error then causes a printk and a return code of -EAGAIN. Replace the intricate scheme with an explicit return code for this sitation and avoid the error message. Reviewd-by:
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Martin Schwidefsky authored
Set the configuration timer at the end of the ap_scan_bus function. Make use of setup_timer and remove some unnecessary add_timer, mod_timer and del_timer_sync calls. Replace the complicated timer_pending, mod_timer and add_timer code in ap_config_time_store with a simple mod_timer. Reviewd-by:
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Martin Schwidefsky authored
If there are no devices on the AP bus there will not be a single call to the per-device ap_bus_suspend function. Even worse, there will not be a call to the per-device ap_bus_resume either and the AP will fail so resume correctly. Introduce a bus specific dev_pm_ops to suspend / resume the AP bus related things. While we are at it, simplify the power management code of the AP bus. Reviewd-by:
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Martin Schwidefsky authored
The ap_queue_messsage function will call device_unregister if the unregistered field of the device has been set while trying to queue a message. This races with other device_unregister calls, e.g. from the ap_scan_bus. Remove the call to device_unregister from ap_queue_message and let ap_scan_bus deal with it. Signed-off-by: -
Martin Schwidefsky authored
The ap_query_configuration function allocates the ap_config_info structure, but there is no code to free the structure. Allocate the structure in the module_init function and free it again in module_exit. While we are at it simplify a few functions in regard to the ap configuration data. Reviewed-by:
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Martin Schwidefsky authored
ap_test_queue, ap_query_facilities, __ap_query_functions all use the same PQAP(TAPQ) command. Consolidate the three into a single ap_test_queue function that returns the AP status and the 64-bit result. The exception table entry for PQAP(TAPQ) can be avoided if the T bit for the APFT facility is set only if test_facility(15) indicated that the facility is present. Integrate ap_query_function into ap_query queue to avoid calling PQAP(TAPQ) twice. Reviewed-by:
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Heiko Carstens authored
The first level machine check handler for etr and stp machine checks may call queue_work() while in nmi context. This may deadlock e.g. if the machine check happened when the interrupted context did hold a lock, that also will be acquired by queue_work(). Therefore split etr and stp machine check handling into first and second level handling. The second level handling will then issue the queue_work() call in process context which avoids the potential deadlock. Signed-off-by:
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Sebastian Ott authored
zpci_err_insn writes stale stack content to the debugfs. Ensure that the struct in zpci_err_insn is ordered in a way that we don't have uninitialized holes in it. In addition to that add the packed attribute. Fixes: 3d8258e4 (s390/pci: move debug messages to debugfs) Signed-off-by:
Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by:
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Heiko Carstens authored
Signed-off-by:
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Heiko Carstens authored
With the removal of 31 bit support a couple of defines became unused. Remove them. Signed-off-by:
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Heiko Carstens authored
For some unknown reason the mcck_interruption_code field is defined as array of two 32 bit values. Given that this actually is a 64 bit field according to the architecture, change the type to u64. Signed-off-by:
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Heiko Carstens authored
The defines that are used in entry.S have been partially converted to use the _BITUL macro (setup.h). This patch converts the rest. Signed-off-by:
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Heiko Carstens authored
The cpu flags and pt_regs flags fields are each 64 bits in size. A flag can be set with helper functions like set_cpu_flags(). These functions create a mask using "1U << flag". This doesn't work if flag is larger than 31, since 1U << 32 == 0. So fix this in case we ever will have such flag numbers. Signed-off-by:
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Heiko Carstens authored
When using systemtap it was observed that our udelay implementation is rather suboptimal if being called from a kprobe handler installed by systemtap. The problem observed when a kprobe was installed on lock_acquired(). When the probe was hit the kprobe handler did call udelay, which set up an (internal) timer and reenabled interrupts (only the clock comparator interrupt) and waited for the interrupt. This is an optimization to avoid that the cpu is busy looping while waiting that enough time passes. The problem is that the interrupt handler still does call irq_enter()/irq_exit() which then again can lead to a deadlock, since some accounting functions may take locks as well. If one of these locks is the same, which caused lock_acquired() to be called, we have a nice deadlock. This patch reworks the udelay code for the interrupts disabled case to immediately leave the low level interrupt handler when the clock comparator interrupt happens. That way no C code is being called and the deadlock cannot happen anymore. Signed-off-by:
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Christian Borntraeger authored
sparse does not understand the s390 specific hotpatch attribute and floods the log with messages like include/uapi/linux/swab.h:92:8: error: attribute 'hotpatch': unknown attribute Let's just dont use it, if __CHECKER__ is defined. Signed-off-by:
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Christian Borntraeger authored
The program parameter can be used to mark hardware samples with some token. Previously, it was used to mark guest samples only. Improve the program parameter doubleword by combining two parts, the leftmost LPP part and the rightmost PID part. Set the PID part for processes by using the task PID. To distinguish host and guest samples for the kernel (PID part is zero), the guest must always set the program paramater to a non-zero value. Use the leftmost bit in the LPP part of the program parameter to be able to detect guest kernel samples. [brueckner@linux.vnet.ibm.com]: Split __LC_CURRENT and introduced __LC_LPP. Corrected __LC_CURRENT users and adjusted assembler parts. And updated the commit message accordingly. Signed-off-by:
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Martin Schwidefsky authored
The use of OFFSET instead of DEFINE makes the definitions in asm-offsets.c more readable. While we are at it sort the defines for struct _lowcore according to the field order and remove some unneeded defines. Signed-off-by: -
Martin Schwidefsky authored
The sclp console and tty code currently uses several message text objects in a single message event to print several lines with one SCCB. This causes the output of these lines to be fused into a block which is noticeable when selecting text in the operating system message panel. Instead use several message events with a single message text object each to print every line on its own. This changes the SCCB layout from struct sccb_header struct evbuf_header struct mdb_header struct go struct mto ... struct mto to struct sccb_header struct evbuf_header struct mdb_header struct go struct mto ... struct evbuf_header struct mdb_header struct go struct mto Reviewed-by: -
Hendrik Brueckner authored
Various functions in entry.S perform test-under-mask instructions to test for particular bits in memory. Because test-under-mask uses a mask value of one byte, the mask value and the offset into the memory must be calculated manually. This easily introduces errors and is hard to review and read. Introduce the TSTMSK assembler macro to specify a mask constant and let the macro calculate the offset and the byte mask to generate a test-under-mask instruction. The benefit is that existing symbolic constants can now be used for tests. Also the macro checks for zero mask values and mask values that consist of multiple bytes. Signed-off-by:
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Hendrik Brueckner authored
Previously, the init task did not have an allocated FPU save area and saving an FPU state was not possible. Now if the vector extension is always enabled, provide a static FPU save area to save FPU states of vector instructions that can be executed quite early. Signed-off-by:
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Hendrik Brueckner authored
If the kernel detects that the s390 hardware supports the vector facility, it is enabled by default at an early stage. To force it off, use the novx kernel parameter. Note that there is a small time window, where the vector facility is enabled before it is forced to be off. With enabling the vector facility by default, the FPU save and restore functions can be improved. They do not longer require to manage expensive control register updates to enable or disable the vector enablement control for particular processes. Signed-off-by:
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Martin Schwidefsky authored
The call to pgste_set_key in ptep_set_access_flags can be avoided if the old pte is found to be valid at the time the new access rights are set. The function that created the old, valid pte already completed the required storage key operation. Signed-off-by: -
Martin Schwidefsky authored
The principles of operation states reads are in order, writes are in order, writes can be reordered after reads, but no reads can be reordered after writes. The atomic and bitops variantes for z196 use the interlocked-access facility instructions with a memory barrier before and after the instruction. Because of the memory ordering the first barrier is unnecessary and can be removed. Acked-by:
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Martin Schwidefsky authored
To be able to analyse problems in regard to hypervisor overhead add a tracepoing for diagnose calls. It reports the number of the diagnose issued, e.g. sshd-1385 [002] .... 42.701431: diagnose: nr=0x9c <idle>-0 [001] ..s. 43.587528: diagnose: nr=0x9c Signed-off-by:
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