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2012-07-20s390/comments: unify copyright messages and remove file namesHeiko Carstens
Remove the file name from the comment at top of many files. In most cases the file name was wrong anyway, so it's rather pointless. Also unify the IBM copyright statement. We did have a lot of sightly different statements and wanted to change them one after another whenever a file gets touched. However that never happened. Instead people start to take the old/"wrong" statements to use as a template for new files. So unify all of them in one go. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-06-14s390/smp: make absolute lowcore / cpu restart parameter accesses more robustHeiko Carstens
Setting the cpu restart parameters is done in three different fashions: - directly setting the four parameters individually - copying the four parameters with memcpy (using 4 * sizeof(long)) - copying the four parameters using a private structure In addition code in entry*.S relies on a certain order of the restart members of struct _lowcore. Make all of this more robust to future changes by adding a mem_absolute_assign(dest, val) define, which assigns val to dest using absolute addressing mode. Also the load multiple instructions in entry*.S have been split into separate load instruction so the order of the struct _lowcore members doesn't matter anymore. In addition move the prototypes of memcpy_real/absolute from uaccess.h to processor.h. These memcpy* variants are not related to uaccess at all. string.h doesn't seem to match as well, so lets use processor.h. Also replace the eight byte array in struct _lowcore which represents a misaliged u64 with a u64. The compiler will always create code that handles the misaligned u64 correctly. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-03-11[S390] Ensure that vmcore_info pointer is never accessed directlyMichael Holzheu
Because the vmcore_info pointer is not 8 byte aligned it never should not be accessed directly. The reason is that the compiler assumes that 64 bit pointer are always double word aligned. To ensure save access, the vmcore_info type in struct lowcore is changed from u64 to an u8[8] array and a comment is added. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-03-11[S390] kernel: Add OS info memory interfaceMichael Holzheu
In order to allow kdump based stand-alone dump, some information has to be passed from the old kernel to the new dump kernel. This is done via a the struct "os_info" that contains the following fields: * crashkernel base and size * reipl block * vmcoreinfo * init function A pointer to os_info is stored at a well known storage location and the whole structure as well as all fields are secured with checksums. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-03-11[S390] rework smp codeMartin Schwidefsky
Define struct pcpu and merge some of the NR_CPUS arrays into it, including __cpu_logical_map, current_set and smp_cpu_state. Split smp related functions to those operating on physical cpus and the functions operating on a logical cpu number. Make the functions for physical cpus use a pointer to a struct pcpu. This hides the knowledge about cpu addresses in smp.c, entry[64].S and swsusp_asm64.S, thus remove the sigp.h header. The PSW restart mechanism is used to start secondary cpus, calling a function on an online cpu, calling a function on the ipl cpu, and for the nmi signal. Replace the different assembler functions with a single function restart_int_handler. The new entry point calls a function whose pointer is stored in the lowcore of the target cpu and it can wait for the source cpu to stop. This covers all existing use cases. Overall the code is now simpler and there are ~380 lines less code. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-03-11[S390] rename lowcore fieldMartin Schwidefsky
The 16 bit value at the lowcore location with offset 0x84 is the cpu address that is associated with an external interrupt. Rename the field from cpu_addr to ext_cpu_addr to make that clear. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-12-27[S390] entry[64].S improvementsMartin Schwidefsky
Another round of cleanup for entry[64].S, in particular the program check handler looks more reasonable now. The code size for the 31 bit kernel has been reduced by 616 byte and by 528 byte for the 64 bit version. Even better the code is a bit faster as well. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-12-27[S390] kvm: move cmf host id constant out of lowcoreMartin Schwidefsky
There is no reason for the cpu-measurement-facility host id constant to reside in the lowcore where space is precious. Use an entry in the literal pool in HANDLE_SIE_INTERCEPT and a stack slot in sie64a. While we are at it replace the id -1 with 0 to indicate host execution. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30[S390] lowcore cleanupMartin Schwidefsky
Remove the save_area_64 field from the 0xe00 - 0xf00 area in the lowcore. Use a free slot in the save_area array instead. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30[S390] Export vmcoreinfo noteMichael Holzheu
This patch defines for s390 an ABI defined pointer to the vmcoreinfo note at a well known address. With this patch tools are able to find this information in dumps created by stand-alone or hypervisor dump tools. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-08-03[S390] Add PSW restart shutdown triggerMichael Holzheu
With this patch a new S390 shutdown trigger "restart" is added. If under z/VM "systerm restart" is entered or under the HMC the "PSW restart" button is pressed, the PSW located at 0 (31 bit) or 0x1a0 (64 bit) bit is loaded. Now we execute do_restart() that processes the restart action that is defined under /sys/firmware/shutdown_actions/on_restart. Currently the following actions are possible: reipl (default), stop, vmcmd, dump, and dump_reipl. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2011-07-24[S390] kvm guest address space mappingMartin Schwidefsky
Add code that allows KVM to control the virtual memory layout that is seen by a guest. The guest address space uses a second page table that shares the last level pte-tables with the process page table. If a page is unmapped from the process page table it is automatically unmapped from the guest page table as well. The guest address space mapping starts out empty, KVM can map any individual 1MB segments from the process virtual memory to any 1MB aligned location in the guest virtual memory. If a target segment in the process virtual memory does not exist or is unmapped while a guest mapping exists the desired target address is stored as an invalid segment table entry in the guest page table. The population of the guest page table is fault driven. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-05-23[S390] pfault: cpu hotplug vs missing completion interruptsHeiko Carstens
On cpu hot remove a PFAULT CANCEL command is sent to the hypervisor which in turn will cancel all outstanding pfault requests that have been issued on that cpu (the same happens with a SIGP cpu reset). The result is that we end up with uninterruptible processes where the interrupt that would wake up these processes never arrives. In order to solve this all processes which wait for a pfault completion interrupt get woken up after a cpu hot remove. The worst case that could happen is that they fault again and in turn need to wait again. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-05-23[S390] Remove data execution protectionMartin Schwidefsky
The noexec support on s390 does not rely on a bit in the page table entry but utilizes the secondary space mode to distinguish between memory accesses for instructions vs. data. The noexec code relies on the assumption that the cpu will always use the secondary space page table for data accesses while it is running in the secondary space mode. Up to the z9-109 class machines this has been the case. Unfortunately this is not true anymore with z10 and later machines. The load-relative-long instructions lrl, lgrl and lgfrl access the memory operand using the same addressing-space mode that has been used to fetch the instruction. This breaks the noexec mode for all user space binaries compiled with march=z10 or later. The only option is to remove the current noexec support. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-25[S390] cleanup facility list handlingMartin Schwidefsky
Store the facility list once at system startup with stfl/stfle and reuse the result for all facility tests. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-05-17[S390] virtualization aware cpu measurementCarsten Otte
Use the SPP instruction to set a tag on entry to / exit of the virtual machine context. This allows the cpu measurement facility to distinguish the samples from the host and the different guests. Signed-off-by: Carsten Otte <cotte@de.ibm.com>
2010-05-17[S390] idle time accounting vs. machine checksMartin Schwidefsky
A machine check can interrupt the i/o and external interrupt handler anytime. If the machine check occurs while the interrupt handler is waking up from idle vtime_start_cpu can get executed a second time and the int_clock / async_enter_timer values in the lowcore get clobbered. This can confuse the cpu time accounting. To fix this problem two changes are needed. First the machine check handler has to use its own copies of int_clock and async_enter_timer, named mcck_clock and mcck_enter_timer. Second the nested execution of vtime_start_cpu has to be prevented. This is done in s390_idle_check by checking the wait bit in the program status word. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-05-17[S390] More cleanup for struct _lowcoreMartin Schwidefsky
Remove cpu_id from lowcore and replace addr_t with __u64. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26[S390] Cleanup struct _lowcore usage and defines.Heiko Carstens
Use asm offsets to make sure the offset defines to struct _lowcore and its layout don't get out of sync. Also add a BUILD_BUG_ON() which checks that the size of the structure is sane. And while being at it change those sites which use odd casts to access the current lowcore. These should use S390_lowcore instead. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26[S390] smp: rename and add lowcore definesHeiko Carstens
Rename __LC_RESTART_PSW to __LC_RST_NEW_PSW, add a define for the missing 32 bit variant and the missing old PSWs. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26[S390] zfcpdump: remove cross arch dump supportHeiko Carstens
Remove support to be able to dump 31 bit systems with a 64 bit dumper. This is mostly useless since no distro ships 31 bit kernels together with a 64 bit dumper. We also get rid of a bit of hacky code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-09[S390] Fix struct _lowcore layout.Heiko Carstens
Offsets and sizes are wrong for 32 bit. Got broken with 866ba284 "[S390] cleanup lowcore.h". Reported-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-22[S390] hibernate: Do real CPU swap at resume timeMichael Holzheu
Currently, when the physical resume CPU is not equal to the physical suspend CPU, we swap the CPUs logically, by modifying the logical/physical CPU mapping. This has two major drawbacks: First the change is visible from user space (e.g. CPU sysfs files) and second it is hard to ensure that nowhere in the kernel the physical CPU ID is stored before suspend. To fix this, we now really swap the physical CPUs, if the resume CPU is not the pysical suspend CPU. We restart the suspend CPU and stop the resume CPU using SIGP restart and SIGP stop. If the suspend CPU is no longer available, we write a message and load a disabled wait PSW. Signed-off-by: Michael Holzheu <michael.holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-22[S390] hibernate: make sure pfn_is_nosave handles lowcore pagesHeiko Carstens
pfn_is_nosave doesn't return the correct value for the second lowcore page if lowcore protection is enabled. Make sure it always returns the correct value. While at it simplify the whole thing. NSS special handling is done by the tprot check like it already works for DCSS as well. So remove the extra code for NSS. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-22[S390] smp: introduce LC_ORDER and simplify lowcore handlingHeiko Carstens
Removes a couple of simple code duplications. But before I have to do this again, just simplify it. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] Get rid of cpuid.h header file.Heiko Carstens
Merge cpuid.h header file into cpu.h. While at it convert from typedef to struct declaration and also convert cio code to use proper lowcore structure instead of casts. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-12[S390] ftrace: add dynamic ftrace supportHeiko Carstens
Dynamic ftrace support for s390. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-12[S390] use facility list for cpu type safety checkMartin Schwidefsky
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-04-14[S390] s390: move machine flags to lowcoreChristian Ehrhardt
Currently the storage of the machine flags is a globally exported unsigned long long variable. By moving the storage location into the lowcore struct we allow assembler code to check machine_flags directly even without needing a register. Addtionally the lowcore and therefore the machine flags too will be in cache most of the time. Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-03-26[S390] cleanup lowcore.hMartin Schwidefsky
The lowcore.h header has quite a lot of whitespace damage and a rather wild collection of entries. Remove all that whitespace and tidy up the order of the lowcore fields. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-03-26[S390] eliminate ipl_device from lowcoreMartin Schwidefsky
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-03-26[S390] eliminate cpuinfo_S390 structureMartin Schwidefsky
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-03-26[S390] Fix comments in lowcore structureChristian Borntraeger
This patch fixes two addresses in the comments for the lowcore structure. Looks like an copy-paste bug. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-03-26[S390] Automatic IPL after dumpFrank Munzert
Provide new shutdown action "dump_reipl" for automatic ipl after dump. Signed-off-by: Frank Munzert <munzert@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2009-02-11[S390] vdso: fix per cpu vdso pointer in lowcoreMartin Schwidefsky
The vdso_per_cpu_data entry in the lowcore structure uses __u32 instead of __u64. If the data page is above 4GB the pointer is truncated and the kernel crashes. Reported-by: Mijo Safradin <mijo@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31[PATCH] fast vdso implementation for CLOCK_THREAD_CPUTIME_IDMartin Schwidefsky
The extract cpu time instruction (ectg) instruction allows the user process to get the current thread cputime without calling into the kernel. The code that uses the instruction needs to switch to the access registers mode to get access to the per-cpu info page that contains the two base values that are needed to calculate the current cputime from the CPU timer with the ectg instruction. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-12-31[PATCH] improve precision of process accounting.Martin Schwidefsky
The unit of the cputime accouting values that are stored per process is currently a microsecond. The CPU timer has a maximum granularity of 2**-12 microseconds. There is no benefit in storing the per process values in the lesser precision and there is the disadvantage that the backend has to do the rounding to microseconds. The better solution is to use the maximum granularity of the CPU timer as cputime unit. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-08-01[S390] move include/asm-s390 to arch/s390/include/asmMartin Schwidefsky
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>