- 14 Jun, 2016 1 commit
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Heiko Carstens authored
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>
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- 13 Jun, 2016 39 commits
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Heiko Carstens authored
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:
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Heiko Carstens authored
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:
Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by:
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Heiko Carstens authored
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:
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Heiko Carstens authored
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:
Michael Holzheu <holzheu@linux.vnet.ibm.com> Reviewed-by:
Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by:
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Heiko Carstens authored
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:
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Heiko Carstens authored
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:
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Heiko Carstens authored
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 a76cf66e ("x86/uaccess: Tell the compiler that uaccess is unlikely to fault"). Signed-off-by:
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Heiko Carstens authored
Fix some whitespace damage that was introduced by me with a query-replace when removing 31 bit support. Signed-off-by:
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Sebastian Ott authored
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:
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Sebastian Ott authored
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:
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Sebastian Ott authored
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:
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Thomas Richter authored
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:
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Heiko Carstens authored
Small cleanup patch to use the shorter __section macro everywhere. Signed-off-by:
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Heiko Carstens authored
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:
Kees Cook <keescook@chromium.org> Signed-off-by:
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Heiko Carstens authored
commit c74ba8b3 ("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:
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Martin Schwidefsky authored
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 authored
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:
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Martin Schwidefsky authored
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 authored
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 authored
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 authored
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 authored
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 authored
The sync clock operation of the channel subsystem call for STP delivers the TOD clock difference as a result. Use this TOD clock difference instead of the difference between the TOD timestamps before and after the sync clock operation. Signed-off-by: -
Heiko Carstens authored
Reducing the size of reserved memory for the crash kernel will result in an immediate crash on s390. Reason for that is that we do not create struct pages for memory that is reserved. If that memory is freed any access to struct pages which correspond to this memory will result in invalid memory accesses and a kernel panic. Fix this by properly creating struct pages when the system gets initialized. Change the code also to make use of set_memory_ro() and set_memory_rw() so page tables will be split if required. Signed-off-by:
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Heiko Carstens authored
Implement an s390 version of the weak crash_free_reserved_phys_range function. This allows us to update the size of the reserved crash kernel memory if it will be resized. This was previously done with a call to crash_unmap_reserved_pages from crash_shrink_memory which was removed with ("s390/kexec: consolidate crash_map/unmap_reserved_pages() and arch_kexec_protect(unprotect)_crashkres()") Fixes: 7a0058ec ("s390/kexec: consolidate crash_map/unmap_reserved_pages() and arch_kexec_protect(unprotect)_crashkres()") Signed-off-by: -
Heiko Carstens authored
The segment/region table that is part of the kernel image must be properly aligned to 16k in order to make the crdte inline assembly work. Otherwise it will calculate a wrong segment/region table start address and access incorrect memory locations if the swapper_pg_dir is not aligned to 16k. Therefore define BSS_FIRST_SECTIONS in order to put the swapper_pg_dir at the beginning of the bss section and also align the bss section to 16k just like other architectures did. Signed-off-by:
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Christian Borntraeger authored
Lets provide the basic machine information for dump_stack on s390. This enables the "Hardware name:" line and results in output like [...] Oops: 0004 ilc:2 [#1] SMP Modules linked in: CPU: 1 PID: 74 Comm: sh Not tainted 4.5.0+ #205 Hardware name: IBM 2964 NC9 704 (KVM) [...] Signed-off-by:
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Daniel van Gerpen authored
Signed-off-by:
Daniel van Gerpen <daniel@vangerpen.de> Acked-by:
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Heiko Carstens authored
Show the dynamic and static cpu mhz of each cpu. Since these values are per cpu this requires a fundamental extension of the format of /proc/cpuinfo. Historically we had only a single line per cpu and a summary at the top of the file. This format is hardly extendible if we want to add more per cpu information. Therefore this patch adds per cpu blocks at the end of /proc/cpuinfo: cpu : 0 cpu Mhz dynamic : 5504 cpu Mhz static : 5504 cpu : 1 cpu Mhz dynamic : 5504 cpu Mhz static : 5504 cpu : 2 cpu Mhz dynamic : 5504 cpu Mhz static : 5504 cpu : 3 cpu Mhz dynamic : 5504 cpu Mhz static : 5504 Right now each block contains only the dynamic and static cpu mhz, but it can be easily extended like on every other architecture. This extension is supposed to be compatible with the old format. Signed-off-by:
Sascha Silbe <silbe@linux.vnet.ibm.com> Signed-off-by:
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Heiko Carstens authored
Change the code to print all the current output during the first iteration. This is a preparation patch for the upcoming per cpu block extension to /proc/cpuinfo. Signed-off-by:
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Jason Baron authored
Ensure that we always have __stringify(). Signed-off-by:
Jason Baron <jbaron@akamai.com> Signed-off-by:
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Heiko Carstens authored
Add statistics that show how memory is mapped within the kernel identity mapping. This is more or less the same like git commit ce0c0e50 ("x86, generic: CPA add statistics about state of direct mapping v4") for x86. I also intentionally copied the lower case "k" within DirectMap4k vs the upper case "M" and "G" within the two other lines. Let's have consistent inconsistencies across architectures. The output of /proc/meminfo now contains these additional lines: DirectMap4k: 2048 kB DirectMap1M: 3991552 kB DirectMap2G: 4194304 kB The implementation on s390 is lockless unlike the x86 version, since I assume changes to the kernel mapping are a very rare event. Therefore it really doesn't matter if these statistics could potentially be inconsistent if read while kernel pages tables are being changed. Signed-off-by:
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Heiko Carstens authored
For the kernel identity mapping map everything read-writeable and subsequently call set_memory_ro() to make the ro section read-only. This simplifies the code a lot. Signed-off-by:
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Heiko Carstens authored
set_memory_ro() and set_memory_rw() currently only work on 4k mappings, which is good enough for module code aka the vmalloc area. However we stumbled already twice into the need to make this also work on larger mappings: - the ro after init patch set - the crash kernel resize code Therefore this patch implements automatic kernel page table splitting if e.g. set_memory_ro() would be called on parts of a 2G mapping. This works quite the same as the x86 code, but is much simpler. In order to make this work and to be architecturally compliant we now always use the csp, cspg or crdte instructions to replace valid page table entries. This means that set_memory_ro() and set_memory_rw() will be much more expensive than before. In order to avoid huge latencies the code contains a couple of cond_resched() calls. The current code only splits page tables, but does not merge them if it would be possible. The reason for this is that currently there is no real life scenarion where this would really happen. All current use cases that I know of only change access rights once during the life time. If that should change we can still implement kernel page table merging at a later time. Signed-off-by:
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Heiko Carstens authored
Make pmd_wrprotect() and pmd_mkwrite() available independently from CONFIG_TRANSPARENT_HUGEPAGE and CONFIG_HUGETLB_PAGE so these can be used on the kernel mapping. Also introduce a couple of pud helper functions, namely pud_pfn(), pud_wrprotect(), pud_mkwrite(), pud_mkdirty() and pud_mkclean() which only work on the kernel mapping. Signed-off-by:
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Heiko Carstens authored
Always use PAGE_KERNEL when re-enabling pages within the kernel mapping due to debug pagealloc. Without using this pgprot value pte_mkwrite() and pte_wrprotect() won't work on such mappings after an unmap -> map cycle anymore. Signed-off-by:
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Heiko Carstens authored
Use pte_clear() instead of open-coding it. Signed-off-by:
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Heiko Carstens authored
_REGION3_ENTRY_RO is a duplicate of _REGION_ENTRY_PROTECT. Signed-off-by:
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Heiko Carstens authored
Instead of open-coded SEGMENT_KERNEL and REGION3_KERNEL assignments use defines. Also to make e.g. pmd_wrprotect() work on the kernel mapping a couple more flags must be set. Therefore add the missing flags also. In order to make everything symmetrical this patch also adds software dirty, young, read and write bits for region 3 table entries. Signed-off-by:
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