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2016-07-04s390: have unique symbol for __switch_to addressHeiko Carstens1-0/+10
After linking there are several symbols for the same address that the __switch_to symbol points to. E.g.: 000000000089b9c0 T __kprobes_text_start 000000000089b9c0 T __lock_text_end 000000000089b9c0 T __lock_text_start 000000000089b9c0 T __sched_text_end 000000000089b9c0 T __switch_to When disassembling with "objdump -d" this results in a missing __switch_to function. It would be named __kprobes_text_start instead. To unconfuse objdump add a nop in front of the kprobes text section. That way __switch_to appears again. Obviously this solution is sort of a hack, since it also depends on link order if this works or not. However it is the best I can come up with for now. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-07-04s390/cpuinfo: show maximum thread idHeiko Carstens1-0/+1
Expose the maximum thread id with /proc/cpuinfo. With the new line the output looks like this: vendor_id : IBM/S390 bogomips per cpu: 20325.00 max thread id : 1 With this new interface it is possible to always tell the correct number of cpu threads potentially being used by the kernel. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/ptrace: clarify bits in the per_structMartin Schwidefsky1-3/+3
The bits single_step and instruction_fetch lost their meaning with git commit 5e9a26928f550157 "[S390] ptrace cleanup". Clarify the comment for these two bits. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390: stack address vs thread_infoHeiko Carstens2-10/+6
Avoid using the address of a process' thread_info structure as the kernel stack address. This will break as soon as the thread_info structure will be removed from the stack, and in addition it makes the code a bit more understandable. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390: remove pointless load within __switch_toHeiko Carstens1-1/+0
Remove a leftover from the code that transferred a couple of TIF bits from the previous task to the next task. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390: enable kcov supportHeiko Carstens5-0/+10
Now that hopefully all inline assemblies have been converted to single basic blocks we can enable kcov on s390. Note that this patch does not disable as many files on s390 like the x86 variant does. Right now I didn't see a reason to do that, however additional files or directories can be excluded at any time. The runtime overhead seems to be quite high. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/cpumf: use basic block for ecctr inline assemblyHeiko Carstens1-3/+14
Use only simple inline assemblies which consist of a single basic block if the register asm construct is being used. Otherwise gcc would generate broken code if the compiler option --sanitize-coverage=trace-pc would be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/hypfs: use basic block for diag inline assemblyHeiko Carstens1-5/+7
Use only simple inline assemblies which consist of a single basic block if the register asm construct is being used. Otherwise gcc would generate broken code if the compiler option --sanitize-coverage=trace-pc would be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/sysinfo: use basic block for stsi inline assemblyHeiko Carstens1-8/+17
Use only simple inline assemblies which consist of a single basic block if the register asm construct is being used. Otherwise gcc would generate broken code if the compiler option --sanitize-coverage=trace-pc would be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/smp: use basic blocks for sigp inline assembliesHeiko Carstens2-10/+15
Use only simple inline assemblies which consist of a single basic block if the register asm construct is being used. Otherwise gcc would generate broken code if the compiler option --sanitize-coverage=trace-pc would be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/cio: use basic blocks for i/o inline assembliesHeiko Carstens1-9/+82
Use only simple inline assemblies which consist of a single basic block if the register asm construct is being used. Otherwise gcc would generate broken code if the compiler option --sanitize-coverage=trace-pc would be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/cio: use basic blocks for cmf inline assembliesHeiko Carstens1-6/+9
Use only simple inline assemblies which consist of a single basic block if the register asm construct is being used. Otherwise gcc would generate broken code if the compiler option --sanitize-coverage=trace-pc would be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/pci: use basic blocks for pci inline assembliesHeiko Carstens1-1/+11
Use only simple inline assemblies which consist of a single basic block if the register asm construct is being used. Otherwise gcc would generate broken code if the compiler option --sanitize-coverage=trace-pc would be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/iucv: use basic blocks for iucv inline assembliesHeiko Carstens1-9/+27
Use only simple inline assemblies which consist of a single basic block if the register asm construct is being used. Otherwise gcc would generate broken code if the compiler option --sanitize-coverage=trace-pc would be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/crypto: use basic blocks for ap bus inline assembliesHeiko Carstens1-28/+49
Use only simple inline assemblies which consist of a single basic block if the register asm construct is being used. Otherwise gcc would generate broken code if the compiler option --sanitize-coverage=trace-pc would be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/mm: use basic block for essa inline assemblyHeiko Carstens1-4/+9
Use only simple inline assemblies which consist of a single basic block if the register asm construct is being used. Otherwise gcc would generate broken code if the compiler option --sanitize-coverage=trace-pc would be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/lib: use basic blocks for inline assembliesHeiko Carstens1-24/+26
Use only simple inline assemblies which consist of a single basic block if the register asm construct is being used. Otherwise gcc would generate broken code if the compiler option --sanitize-coverage=trace-pc would be used. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/uaccess: fix __put_get_user_asm defineHeiko Carstens1-2/+59
The __put_get_user_asm defines an inline assmembly which makes use of the asm register construct. The parameters passed to that define may also contain function calls. It is a gcc restriction that between register asm statements and the use of any such annotated variables function calls may clobber the register / variable contents. Or in other words: gcc would generate broken code. This can be achieved e.g. with the following code: get_user(x, func() ? a : b); where the call of func would clobber register zero which is used by the __put_get_user_asm define. To avoid this add two static inline functions which don't have these side effects. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/cpuinfo: rename cpu field to cpu numberHeiko Carstens1-1/+1
The cpu field name within /proc/cpuinfo has a conflict with the powerpc and sparc output where it contains the cpu model name. So rename the field name to cpu number which shouldn't generate any conflicts. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/perf: remove perf_release/reserver_sampling functionsHeiko Carstens3-47/+0
Now that the oprofile sampling code is gone there is only one user of the sampling facility left. Therefore the reserve and release functions can be removed. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-28s390/oprofile: remove hardware sampler supportHeiko Carstens6-1754/+0
Remove hardware sampler support from oprofile module. The oprofile user space utilty has been switched to use the kernel perf interface, for which we also provide hardware sampling support. In addition the hardware sampling support is also slightly broken: it supports only 16 bits for the pid and therefore would generate wrong results on machines which have a pid >64k. Also the pt_regs structure which was passed to oprofile common code cannot necessarily be used to generate sane backtraces, since the task(s) in question may run while the samples are fed to oprofile. So the result would be more or less random. However given that the only user space tools switched to the perf interface already four years ago the hardware sampler code seems to be unused code, and therefore it should be reasonable to remove it. The timer based oprofile support continues to work. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Andreas Arnez <arnez@linux.vnet.ibm.com> Acked-by: Andreas Krebbel <krebbel@linux.vnet.ibm.com> Acked-by: Robert Richter <rric@kernel.org> Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-15s390: remove math emulation codeHeiko Carstens4-238/+0
The last in-kernel user is gone so we can finally remove this code. Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-15s390: calculate loops_per_jiffies with fp instructionsHeiko Carstens1-17/+21
Implement calculation of loops_per_jiffies with fp instructions which are available on all 64 bit machines. To save and restore floating point register context use the new vx support functions. Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-15s390: Updated kernel config filesHendrik Brueckner4-0/+7
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-15s390/crc32-vx: add crypto API module for optimized CRC-32 algorithmsHendrik Brueckner3-0/+326
Add a crypto API module to access the vector extension based CRC-32 implementations. Users can request the optimized implementation through the shash crypto API interface. Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-14s390/crc32-vx: use vector instructions to optimize CRC-32 computationHendrik Brueckner2-0/+475
Use vector instructions to optimize the computation of CRC-32 checksums. An optimized version is provided for CRC-32 (IEEE 802.3 Ethernet) in normal and bitreflected domain, as well as, for bitreflected CRC-32C (Castagnoli). Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-14s390/vx: add support functions for in-kernel FPU useHendrik Brueckner4-1/+335
Introduce the kernel_fpu_begin() and kernel_fpu_end() function to enclose any in-kernel use of FPU instructions and registers. In enclosed sections, you can perform floating-point or vector (SIMD) computations. The functions take care of saving and restoring FPU register contents and controls. For usage details, see the guidelines in arch/s390/include/asm/fpu/api.h Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-14s390/mm: fix compile for PAGE_DEFAULT_KEY != 0Heiko Carstens2-5/+6
The usual problem for code that is ifdef'ed out is that it doesn't compile after a while. That's also the case for the storage key initialisation code, if it would be used (set PAGE_DEFAULT_KEY to something not zero): ./arch/s390/include/asm/page.h: In function 'storage_key_init_range': ./arch/s390/include/asm/page.h:36:2: error: implicit declaration of function '__storage_key_init_range' Since the code itself has been useful for debugging purposes several times, remove the ifdefs and make sure the code gets compiler coverage. The cost for this is eight bytes. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/topology: remove z10 special handlingHeiko Carstens1-56/+8
I don't have a z10 to test this anymore, so I have no idea if the code works at all or even crashes. I can try to emulate, but it is just guess work. Nor do we know if the z10 special handling is performance wise still better than the generic handling. There have been a lot of changes to the scheduler. Therefore let's play safe and remove the special handling. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/topology: add drawer scheduling domain levelHeiko Carstens4-11/+55
The z13 machine added a fourth level to the cpu topology information. The new top level is called drawer. A drawer contains two books, which used to be the top level. Adding this additional scheduling domain did show performance improvements for some workloads of up to 8%, while there don't seem to be any workloads impacted in a negative way. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13topology/sysfs: provide drawer id and siblings attributesHeiko Carstens2-8/+45
The s390 cpu topology gained another hierarchy level. The top level is now called drawer and contains several books. A book used to be the top level. In order to expose the cpu topology to user space allow to create new sysfs attributes dependent on CONFIG_SCHED_DRAWER which an architecture may define and select. These additional attributes will be available: /sys/devices/system/cpu/cpuX/topology/drawer_id /sys/devices/system/cpu/cpuX/topology/drawer_siblings /sys/devices/system/cpu/cpuX/topology/drawer_siblings_list Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/ipl: rename diagnose enumsHeiko Carstens3-14/+14
Rename DIAG308_IPL and DIAG308_DUMP to DIAG308_LOAD_CLEAR and DIAG308_LOAD_NORMAL_DUMP to better reflect the associated IPL functions. Suggested-by: Cornelia Huck <cornelia.huck@de.ibm.com> Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/ipl: use load normal for LPAR re-iplHeiko Carstens1-1/+4
Avoid clearing memory for CCW-type re-ipl within a logical partition. This can save a significant amount of time if a logical partition contains a lot of memory. On the other hand we still clear memory if running within a second level hypervisor, since the hypervisor can simply free all memory that was used for the guest. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390: avoid extable collisionsHeiko Carstens5-5/+5
We have some inline assemblies where the extable entry points to a label at the end of an inline assembly which is not followed by an instruction. On the other hand we have also inline assemblies where the extable entry points to the first instruction of an inline assembly. If a first type inline asm (extable point to empty label at the end) would be directly followed by a second type inline asm (extable points to first instruction) then we would have two different extable entries that point to the same instruction but would have a different target address. This can lead to quite random behaviour, depending on sorting order. I verified that we currently do not have such collisions within the kernel. However to avoid such subtle bugs add a couple of nop instructions to those inline assemblies which contain an extable that points to an empty label. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/uaccess: use __builtin_expect for get_user/put_userHeiko Carstens1-2/+2
We always expect that get_user and put_user return with zero. Give the compiler a hint so it can slightly optimize the code and avoid branches. This is the same what x86 got with commit a76cf66e948a ("x86/uaccess: Tell the compiler that uaccess is unlikely to fault"). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/uaccess: fix whitespace damageHeiko Carstens1-3/+3
Fix some whitespace damage that was introduced by me with a query-replace when removing 31 bit support. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/pci: ensure to not cross a dma segment boundarySebastian Ott1-1/+2
When we use the iommu_area_alloc helper to get dma addresses we specify the boundary_size parameter but not the offset (called shift in this context). As long as the offset (start_dma) is a multiple of the boundary we're ok (on current machines start_dma always seems to be 4GB). Don't leave this to chance and specify the offset for iommu_area_alloc. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/pci: ensure page aligned dma start addressSebastian Ott1-0/+1
We don't have an architectural guarantee on the value of the dma offset but rely on it to be at least page aligned. Enforce page alignemt of start_dma. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390: use SPARSE_IRQSebastian Ott3-18/+7
Use dynamically allocated irq descriptors on s390 which allows us to get rid of the s390 specific config option PCI_NR_MSI and exploit more MSI interrupts. Also the size of the kernel image is reduced by 131K (using performance_defconfig). Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/Documentation: improve sort command for trace bufferThomas Richter1-1/+1
When s390 traces with hex_ascii or sprintf view are extracted and sorted, use the sort option -s (stable) to avoid multiple lines with the same time stamp being sorted using the rest of the line as secondary key. Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390: use __section macro everywhereHeiko Carstens3-5/+5
Small cleanup patch to use the shorter __section macro everywhere. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390: add proper __ro_after_init supportHeiko Carstens5-11/+19
On s390 __ro_after_init is currently mapped to __read_mostly which means that data marked as __ro_after_init will not be protected. Reason for this is that the common code __ro_after_init implementation is x86 centric: the ro_after_init data section was added to rodata, since x86 enables write protection to kernel text and rodata very late. On s390 we have write protection for these sections enabled with the initial page tables. So adding the ro_after_init data section to rodata does not work on s390. In order to make __ro_after_init work properly on s390 move the ro_after_init data, right behind rodata. Unlike the rodata section it will be marked read-only later after all init calls happened. This s390 specific implementation adds new __start_ro_after_init and __end_ro_after_init labels. Everything in between will be marked read-only after the init calls happened. In addition to the __ro_after_init data move also the exception table there, since from a practical point of view it fits the __ro_after_init requirements. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13vmlinux.lds.h: allow arch specific handling of ro_after_init data sectionHeiko Carstens1-1/+9
commit c74ba8b3480d ("arch: Introduce post-init read-only memory") introduced the __ro_after_init attribute which allows to add variables to the ro_after_init data section. This new section was added to rodata, even though it contains writable data. This in turn causes problems on architectures which mark the page table entries read-only that point to rodata very early. This patch allows architectures to implement an own handling of the .data..ro_after_init section. Usually that would be: - mark the rodata section read-only very early - mark the ro_after_init section read-only within mark_rodata_ro Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/mm: simplify the TLB flushing codeMartin Schwidefsky6-48/+28
ptep_flush_lazy and pmdp_flush_lazy use mm->context.attach_count to decide between a lazy TLB flush vs an immediate TLB flush. The field contains two 16-bit counters, the number of CPUs that have the mm attached and can create TLB entries for it and the number of CPUs in the middle of a page table update. The __tlb_flush_asce, ptep_flush_direct and pmdp_flush_direct functions use the attach counter and a mask check with mm_cpumask(mm) to decide between a local flush local of the current CPU and a global flush. For all these functions the decision between lazy vs immediate and local vs global TLB flush can be based on CPU masks. There are two masks: the mm->context.cpu_attach_mask with the CPUs that are actively using the mm, and the mm_cpumask(mm) with the CPUs that have used the mm since the last full flush. The decision between lazy vs immediate flush is based on the mm->context.cpu_attach_mask, to decide between local vs global flush the mm_cpumask(mm) is used. With this patch all checks will use the CPU masks, the old counter mm->context.attach_count with its two 16-bit values is turned into a single counter mm->context.flush_count that keeps track of the number of CPUs with incomplete page table updates. The sole user of this counter is finish_arch_post_lock_switch() which waits for the end of all page table updates. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13bitmap: bitmap_equal memcmp optimizationMartin Schwidefsky1-0/+4
The bitmap_equal function has optimized code for small bitmaps with less than BITS_PER_LONG bits. For larger bitmaps the out-of-line function __bitmap_equal is called. For a constant number of bits divisible by BITS_PER_LONG the memcmp function can be used. For s390 gcc knows how to optimize this function, memcmp calls with up to 256 bytes / 2048 bits are translated into a single instruction. Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/mm: fix vunmap vs finish_arch_post_lock_switchMartin Schwidefsky1-2/+18
The vunmap_pte_range() function calls ptep_get_and_clear() without any locking. ptep_get_and_clear() uses ptep_xchg_lazy()/ptep_flush_direct() for the page table update. ptep_flush_direct requires that preemption is disabled, but without any locking this is not the case. If the kernel preempts the task while the attach_counter is increased an endless loop in finish_arch_post_lock_switch() will occur the next time the task is scheduled. Add explicit preempt_disable()/preempt_enable() calls to the relevant functions in arch/s390/mm/pgtable.c. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/time: remove ETR supportMartin Schwidefsky5-1229/+55
The External-Time-Reference (ETR) clock synchronization interface has been superseded by Server-Time-Protocol (STP). Remove the outdated ETR interface. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/time: add leap seconds to initial system timeMartin Schwidefsky2-2/+33
The PTFF instruction can be used to retrieve information about UTC including the current number of leap seconds. Use this value to convert the coordinated server time value of the TOD clock to a proper UTC timestamp to initialize the system time. Without this correction the system time will be off by the number of leap seonds until it has been corrected via NTP. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/time: LPAR offset handlingMartin Schwidefsky4-11/+55
It is possible to specify a user offset for the TOD clock, e.g. +2 hours. The TOD clock will carry this offset even if the clock is synchronized with STP. This makes the time stamps acquired with get_sync_clock() useless as another LPAR migth use a different TOD offset. Use the PTFF instrution to get the TOD epoch difference and subtract it from the TOD clock value to get a physical timestamp. As the epoch difference contains the sync check delta as well the LPAR offset value to the physical clock needs to be refreshed after each clock synchronization. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/time: move PTFF definitionsMartin Schwidefsky2-32/+33
The PTFF instruction is not a function of ETR, rename and move the PTFF definitions from etr.h to timex.h. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>