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2014-10-27s390/ftrace,kprobes: allow to patch first instructionHeiko Carstens
If the function tracer is enabled, allow to set kprobes on the first instruction of a function (which is the function trace caller): If no kprobe is set handling of enabling and disabling function tracing of a function simply patches the first instruction. Either it is a nop (right now it's an unconditional branch, which skips the mcount block), or it's a branch to the ftrace_caller() function. If a kprobe is being placed on a function tracer calling instruction we encode if we actually have a nop or branch in the remaining bytes after the breakpoint instruction (illegal opcode). This is possible, since the size of the instruction used for the nop and branch is six bytes, while the size of the breakpoint is only two bytes. Therefore the first two bytes contain the illegal opcode and the last four bytes contain either "0" for nop or "1" for branch. The kprobes code will then execute/simulate the correct instruction. Instruction patching for kprobes and function tracer is always done with stop_machine(). Therefore we don't have any races where an instruction is patched concurrently on a different cpu. Besides that also the program check handler which executes the function trace caller instruction won't be executed concurrently to any stop_machine() execution. This allows to keep full fault based kprobes handling which generates correct pt_regs contents automatically. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-10-09s390: add support for vector extensionMartin Schwidefsky
The vector extension introduces 32 128-bit vector registers and a set of instruction to operate on the vector registers. The kernel can control the use of vector registers for the problem state program with a bit in control register 0. Once enabled for a process the kernel needs to retain the content of the vector registers on context switch. The signal frame is extended to include the vector registers. Two new register sets NT_S390_VXRS_LOW and NT_S390_VXRS_HIGH are added to the regset interface for the debugger and core dumps. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-09-09s390: remove unused MACHINE_FLAG_RRBMHeiko Carstens
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-05-20s390/mm: Convert bootmem to memblockPhilipp Hachtmann
The original bootmem allocator is getting replaced by memblock. To cover the needs of the s390 kdump implementation the physical memory list is used. With this patch the bootmem allocator and its bitmaps are completely removed from s390. Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-04-03s390/mm,tlb: optimize TLB flushing for zEC12Martin Schwidefsky
The zEC12 machines introduced the local-clearing control for the IDTE and IPTE instruction. If the control is set only the TLB of the local CPU is cleared of entries, either all entries of a single address space for IDTE, or the entry for a single page-table entry for IPTE. Without the local-clearing control the TLB flush is broadcasted to all CPUs in the configuration, which is expensive. The reset of the bit mask of the CPUs that need flushing after a non-local IDTE is tricky. As TLB entries for an address space remain in the TLB even if the address space is detached a new bit field is required to keep track of attached CPUs vs. CPUs in the need of a flush. After a non-local flush with IDTE the bit-field of attached CPUs is copied to the bit-field of CPUs in need of a flush. The ordering of operations on cpu_attach_mask, attach_count and mm_cpumask(mm) is such that an underindication in mm_cpumask(mm) is prevented but an overindication in mm_cpumask(mm) is possible. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2014-02-21s390/setup: get rid of MACHINE_HAS_MVCOS machine flagHeiko Carstens
MACHINE_HAS_MVCOS is used exactly once when the machine is brought up. There is no need to cache the flag in the machine_flags. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-11-15s390/sclp: Consolidate early sclp init calls to sclp_early_detect()Michael Holzheu
The new function calls the old ones. The sclp_event_mask_early() is removed and replaced by one invocation of sclp_set_event_mask(0, 0). Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-11-15s390/sclp: Determine HSA size dynamically for zfcpdumpMichael Holzheu
Currently we have hardcoded the HSA size to 32 MiB. With this patch the HSA size is determined dynamically via SCLP in early.c. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-10-24s390/mm: do not initialize storage keysMartin Schwidefsky
With dirty and referenced bits implemented in software it is unnecessary to initialize the storage key for every page. With this patch not a single storage key operation is done for a system that does not use KVM. For KVM set_pte_at/pgste_set_key will do the initialization for the guest view of the storage key when the mapping for the page is established in the host. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-05-02s390/mem_detect: limit memory detection loop to "mem=" parameterHeiko Carstens
The current memory detection loop will detect all present memory of a machine. This is true even if the user specified the "mem=" parameter on the kernel command line. This can be a problem since the memory detection may cause a fully populated host page table for the guest, even for those parts of the memory that the guest will never use afterwards. So fix this and only detect memory up to a user supplied "mem=" limit if specified. Reported-by: Michael Johanssen <johanssn@de.ibm.com> Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-02-14s390/cleanup: rename SPP to LPPHendrik Brueckner
The set-program-parameter (SPP) instruction has been renamed to load-program-parameter (LPP) (see SA23-2260). Reflect this change and rename all macro/instruction references. Also remove the duplicate SPP/LPP entry in the kernel disassembler instruction list. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2013-02-14s390/time: rename tod clock access functionsHeiko Carstens
Fix name clash with some common code device drivers and add "tod" to all tod clock access function names. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-10-09s390/mm: use pfmf instruction to initialize storage keysHeiko Carstens
Make use of the pfmf instruction, if available, to initialize storage keys of whole 1MB or 2GB frames instead of initializing every single page with the sske instruction. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-10-09s390/facilities: cleanup PFMF and HPAGE machine facility detectionHeiko Carstens
MACHINE_HAS_PFMF and MACHINE_HAS_HPAGE actually have the same semantics: the cpu has the EDAT1 facility installed in zArch mode. So remove one of the feature flags in machine_flags and rename the other one to EDAT1. The two old macros simply get mapped to MACHINE_HAS_EDAT1. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-10-09thp, s390: architecture backend for thp on s390Gerald Schaefer
This implements the architecture backend for transparent hugepages on s390. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-26s390/sysinfo,stsi: change return code handlingHeiko Carstens
Change return code handling of the stsi() function: In case function code 0 was specified the return value is the current configuration level (already shifted). That way all the code that actually copied the stsi_0() function can go away. Otherwise the return value is 0 (success) or negative to indicate an error (currently only -EOPNOTSUPP). Also stsi() is no longer an inline function. The function is not performance critical, but every caller would generate an exception table entry for this function. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-09-26s390/exceptions: switch to relative exception table entriesHeiko Carstens
This is the s390 port of 70627654 "x86, extable: Switch to relative exception table entries". Reduces the size of our exception tables by 50% on 64 bit builds. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-09-26s390/sysinfo,topology: fix cpu topology maximum nesting detectionHeiko Carstens
The maximum nesting of the cpu topology is evaluated when /proc/sysinfo is the first time read. This happens without a lock and a concurrent reader on a different cpu can see and use an invalid intermediate value. Besides the fact that this race is quite unlikely the worst thing that could happen is that /proc/sysinfo would contain bogus information about the machine's cpu topology. Nevertheless this should be fixed. So move the detection code to the early machine detection code and since now the value is early available use it in the topology code as well. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-09-26s390: add support for transactional memoryMartin Schwidefsky
Allow user-space processes to use transactional execution (TX). If the TX facility is available user space programs can use transactions for fine-grained serialization based on the data objects that are referenced during a transaction. This is useful for lockless data structures and speculative compiler optimizations. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-09-26s390: enable large page support with CONFIG_DEBUG_PAGEALLOCGerald Schaefer
So far, large page support was completely disabled with CONFIG_DEBUG_PAGEALLOC, although it would be sufficient if only the large page kernel mapping was disabled. This patch enables large page support with CONFIG_DEBUG_PAGEALLOC, while it prevents the large kernel mapping in that case. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-07-26s390/exceptions: sort exception table at build timeHeiko Carstens
Follow x86 and MIPS and sort the main exception table at build time. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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>
2012-05-23s390/kexec: Move early_pgm_check_handler() to text sectionMichael Holzheu
The early_pgm_check_handler() function is also used after the init phase in s390_reset_system(). Therefore it must not be in the init section. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-05-16s390/time: always use stckf instead of stck if availableHeiko Carstens
The store clock fast instruction saves a couple of instructions compared to the store clock instruction. Always use stckf instead of stck if it is available. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2012-03-28Disintegrate asm/system.h for S390David Howells
Disintegrate asm/system.h for S390. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-s390@vger.kernel.org
2012-03-11[S390] kernel: Add z/VM LGR detectionMichael Holzheu
Currently the following mechanisms are available to move active Linux on System z instances between machines: * z/VM 6.2 SSI (Single System Image) * Suspend/resume For moving Linux instances in this patch the term LGR (Linux Guest Relocation) is used. Because such an operation is critical, it should be detectable from Linux. With this patch for both, a live system and a kernel dump, the information about LGRs is accessible. To identify a guest, stsi and stfle data is used. A new function lgr_info_log() compares the current data (lgr_info_cur) with the last recorded one (lgr_info_last). In case the two data sets differ, lgr_info_cur is logged to the "lgr" s390dbf. The following trigger points call lgr_info_log(): * panic * die * kdump * LGR timer * PSW restart * QDIO recovery * resume This patch also changes the s390dbf hex_ascii view. Now only printable ASCII characters are shown. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-12-27[S390] Check for NULL termination in command line setupMichael Holzheu
The current code in setup_boot_command_line() uses a heuristic to detect an EBCDIC command line. It checks if any of the bytes in the command line has bit one (0x80) set. In that case it is assumed that we have an EBCDIC string and the complete command line is converted. On s390 there are cases where the boot loader provides a kernel command line that is NULL terminated, but has random data after the NULL termination. In that case, setup_boot_command_line() might misinterpret an ASCII string for an EBCDIC string. A subsequent string conversion can then damage the ASCII string. This patch solves the problem by checking for NULL termination. If no EBCDIC character has been found until the the NULL termination has been found, we now assume that we have an ASCII string. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-11-14[S390] avoid STCKF if running in ESA modeJan Glauber
In ESA mode STCKF is not defined even if the facility bit is enabled. To prevent an illegal operation we must also check if we run a 64 bit kernel. To make the check perform well add the STCKF bit to the machine flags. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-10-30[S390] cleanup psw related bits and piecesMartin Schwidefsky
Split out addressing mode bits from PSW_BASE_BITS, rename PSW_BASE_BITS to PSW_MASK_BASE, get rid of psw_user32_bits, remove unused function enabled_wait(), introduce PSW_MASK_USER, and drop PSW_MASK_MERGE macros. Change psw_kernel_bits / psw_user_bits to contain only the bits that are always set in the respective mode. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-08-24[S390] nss,initrd: kernel image and initrd must be in different segmentsHeiko Carstens
When IPL'ing from a block device and an NSS should be created we must make sure that the kernel image and the initrd are in different 1MB segments. Otherwise creating the NSS will fail. So we make sure the initrd is 4MB behind the end of the kernel image like we do already when IPL via the VM reader is performed. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-03-23[S390] early: limit savesys cmd string handlingHeiko Carstens
Use snprintf() here as well so we won't have to deal with this again. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-03-23[S390] early: Fix possible overlapping data bufferChen Liu
This patch fixed bugzilla #12965: https://bugzilla.kernel.org/show_bug.cgi?id=12965 The original code contains some inproper use of sprintf function where a buffer is used both as input string as well as output string. It should remember the written bytes in the previous and use that as the offset for later writing. Also replace sprintf with snprintf. Signed-off-by: Chen Liu <chenliu@asset.uwaterloo.ca> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-29[S390] facility detection: remove unused variableHeiko Carstens
arch/s390/kernel/early.c: In function 'setup_hpage': arch/s390/kernel/early.c:285:15: warning: unused variable 'facilities' Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-10-25[S390] topology: clean up facility detectionHeiko Carstens
Move cpu topology facility detection to early setup code where it should be. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> 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>
2010-10-25[S390] add support for nonquiescing sskeMartin Schwidefsky
Improve performance of the sske operation by using the nonquiescing variant if the affected page has no mappings established. On machines with no support for the new sske variant the mask bit will be ignored. 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>
2010-04-09[S390] nss: add missing .previous statement to asm functionHeiko Carstens
The savesys_ipl_nss asm function is put into the .init.text section however it is missing a ".previous" section which would restore the previous section. Luckily all functions in early.c are init functions so it doesn't matter currently. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26[S390] codepage conversion of kernel parameter lineMartin Schwidefsky
Move the ebcdic to ascii conversion of the kernel parameter line from head.S to early.c and convert the assembler code to C. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2010-02-26[S390] add MACHINE_IS_LPAR flagMartin Schwidefsky
Introduce the MACHINE_IS_LPAR flag for code that should only be executed if Linux is running in an LPAR. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-11-13[S390] reset cputime accounting after IPL from NSSMartin Schwidefsky
After an IPL from NSS the uptime of the system is incorrect. The reason is that the startup code in head.S is not executed in case of an IPL from NSS. Due to that sched_clock_base_cc which is used to initialze wall_to_monotonic contains the time stamp when the NSS has been created instead of the time stamp of the system start. Reinitialize the cputime accounting values in create_kernel_nss after the SAVESYS CP command that created the NSS segment. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] kernel: Print an error message if kernel NSS cannot be definedHendrik Brueckner
If a named saved system (NSS) cannot be defined or saved, print out an error message with the return code of the underlying z/VM CP command. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] kernel: always keep machine flags in lowcoreHeiko Carstens
Eleminate the local variable machine_flags and always change machine flags directly in the lowcore. This avoids confusion about when and why the two variables have to be synchronized. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-09-11[S390] kernel: Append scpdata to kernel boot command lineHendrik Brueckner
Append scpdata to the kernel boot command line. If scpdata starts with the equal sign (=), the kernel boot command line is replaced. (For consistency with zIPL and IPL PARM parameters.) To use scpdata for the kernel boot command line, scpdata must consist of ascii characters only. If scpdata contains other characters, scpdata is not appended to the kernel boot command line. In addition, re-IPL is extended for setting scpdata for the next Linux reboot. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-08-07[S390] kernel: Storing machine flags early in lowcoreHendrik Brueckner
Currently, the machine_flags are stored late in the startup initialization which results in failing machine type checks (e.g. for MACHINE_IS_VM). To allow these checks, store the machine flags in the lowcore when the machine type has been detected. Moving the machine_flags to the lowcore has been introduced with git commit 25097bf153391f7be4c591d47061b3dc4990dac2 Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-07-24[S390] hibernation: fix lowcore handlingHeiko Carstens
Our swsusp_arch_suspend() backend implementation disables prefixing by setting the contents of the prefix register to 0. However afterwards common code functions are called which might access percpu data structures. Since the lowcore contains e.g. the percpu base pointer this isn't a good idea. So fix this by copying the hibernating cpu's lowcore to absolute address zero. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2009-06-16[S390] s390: hibernation support for s390Hans-Joachim Picht
This patch introduces the hibernation backend support to the s390 architecture. Now it is possible to suspend a mainframe Linux guest using the following command: echo disk > /sys/power/state Signed-off-by: Hans-Joachim Picht <hans@linux.vnet.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>
2009-04-14[S390] add read_persistent_clockMartin Schwidefsky
Add a read_persistent_clock function that does not just return 0. Since timekeeping_init calls the function before time_init has been called move reset_tod_clock to early.c to make sure that the TOD clock is running when read_persistent_clock is invoked. 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>