- 15 Feb, 2023 4 commits
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Heiko Carstens authored
Add test_and_set_cpu_flag() and test_and_clear_cpu_flag() helper functions. Reviewed-by:
Sven Schnelle <svens@linux.ibm.com> Signed-off-by:
Heiko Carstens <hca@linux.ibm.com>
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Heiko Carstens authored
Let cpu helper functions return boolean values. This also allows to make the code a bit simpler by getting rid of the "!!" construct. Reviewed-by:
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Heiko Carstens authored
Baoquan He reported lots of KFENCE reports when /proc/kcore is read, e.g. with crash or even simpler with dd: BUG: KFENCE: invalid read in copy_from_kernel_nofault+0x5e/0x120 Invalid read at 0x00000000f4f5149f: copy_from_kernel_nofault+0x5e/0x120 read_kcore+0x6b2/0x870 proc_reg_read+0x9a/0xf0 vfs_read+0x94/0x270 ksys_read+0x70/0x100 __do_syscall+0x1d0/0x200 system_call+0x82/0xb0 The reason for this is that read_kcore() simply reads memory that might have been unmapped by KFENCE with copy_from_kernel_nofault(). Any fault due to pages being unmapped by KFENCE would be handled gracefully by the fault handler (exception table fixup). However the s390 fault handler first reports the fault, and only afterwards would perform the exception table fixup. Most architectures have this in reversed order, which also avoids the false positive KFENCE reports when an unmapped page is accessed. Therefore change the s390 fault handler so it handles exception table fixups before KFENCE page faults are reported. Reported-by:
Baoquan He <bhe@redhat.com> Tested-by:
Alexander Potapenko <glider@google.com> Link: https://lore.kernel.org/r/20230213183858.1473681-1-hca@linux.ibm.comSigned-off-by:
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Harald Freudenberger authored
Modify the CPRBX struct to expose a new field ctfm for use with hardware command filtering within a CEX8 crypto card in CCA coprocessor mode. The field replaces a reserved byte padding field so that the layout of the struct and the size does not change. The new field is used only by user space applications which may use this to expose the HW filtering facilities in the crypto firmware layers. Signed-off-by:
Harald Freudenberger <freude@linux.ibm.com> Signed-off-by:
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- 14 Feb, 2023 7 commits
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Heiko Carstens authored
The comment for addr_t doesn't make too much sense. Given that also the formatting is incorrect, just remove it. Signed-off-by: -
Eric Farman authored
The logic in vfio_ccw_sch_shutdown() always assumed that the input subchannel would point to a vfio_ccw_private struct, without checking that one exists. The blamed commit put in a check for this scenario, to prevent the possibility of a missing private. The trouble is that check was put alongside a WARN_ON(), presuming that such a scenario would be a cause for concern. But this can be triggered by binding a subchannel to vfio-ccw, and rebooting the system before starting the mdev (via "mdevctl start" or similar) or after stopping it. In those cases, shutdown doesn't need to worry because either the private was never allocated, or it was cleaned up by vfio_ccw_mdev_remove(). Remove the WARN_ON() piece of this check, since there are plausible scenarios where private would be NULL in this path. Fixes: 9e6f07cd ("vfio/ccw: create a parent struct") Signed-off-by:
Eric Farman <farman@linux.ibm.com> Reviewed-by:
Matthew Rosato <mjrosato@linux.ibm.com> Link: https://lore.kernel.org/r/20230210174227.2256424-1-farman@linux.ibm.comSigned-off-by:
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Heiko Carstens authored
Get rid of CONFIG_AS_IS_LLVM in entry.S to make the code a bit more readable. This removes a micro-optimization, but given that the llvm IAS limitation will likely stay, just use the version that works with llvm. See commit 4c25f0ff ("s390/entry: workaround llvm's IAS limitations") for further details. Signed-off-by:
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Vasily Gorbik authored
Commit bf64f051 ("s390/mem_detect: handle online memory limit just once") introduced truncation of mem_detect online ranges based on identity mapping size. For kdump case however the full set of online memory ranges has to be feed into memblock_physmem_add so that crashed system memory could be extracted. Instead of truncating introduce a "usable limit" which is respected by mem_detect api. Also add extra online memory ranges iterator which still provides full set of online memory ranges disregarding the "usable limit". Fixes: bf64f051 ("s390/mem_detect: handle online memory limit just once") Reported-by:
Alexander Egorenkov <egorenar@linux.ibm.com> Tested-by:
Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by:
Vasily Gorbik <gor@linux.ibm.com> Signed-off-by:
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Heiko Carstens authored
The __uint128_t member was only added for future convenience to the __vector128 struct. However this is a uapi header file, 31/32 bit (aka compat layer) is still supported, but doesn't know anything about this type: /usr/include/asm/types.h:27:17: error: unknown type name __uint128_t 27 | __uint128_t v; Therefore remove it again. Fixes: b0b7b43f ("s390/vx: add 64 and 128 bit members to __vector128 struct") Signed-off-by:
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Gerald Schaefer authored
RDP instruction allows to reset DAT-protection bit in a PTE, with less CPU synchronization overhead than IPTE instruction. In particular, IPTE can cause machine-wide synchronization overhead, and excessive IPTE usage can negatively impact machine performance. RDP can be used instead of IPTE, if the new PTE only differs in SW bits and _PAGE_PROTECT HW bit, for PTE protection changes from RO to RW. SW PTE bit changes are allowed, e.g. for dirty and young tracking, but none of the other HW-defined part of the PTE must change. This is because the architecture forbids such changes to an active and valid PTE, which is why invalidation with IPTE is always used first, before writing a new entry. The RDP optimization helps mainly for fault-driven SW dirty-bit tracking. Writable PTEs are initially always mapped with HW _PAGE_PROTECT bit set, to allow SW dirty-bit accounting on first write protection fault, where the DAT-protection would then be reset. The reset is now done with RDP instead of IPTE, if RDP instruction is available. RDP cannot always guarantee that the DAT-protection reset is propagated to all CPUs immediately. This means that spurious TLB protection faults on other CPUs can now occur. For this, common code provides a flush_tlb_fix_spurious_fault() handler, which will now be used to do a CPU-local TLB flush. However, this will clear the whole TLB of a CPU, and not just the affected entry. For more fine-grained flushing, by simply doing a (local) RDP again, flush_tlb_fix_spurious_fault() would need to also provide the PTE pointer. Note that spurious TLB protection faults cannot really be distinguished from racing pagetable updates, where another thread already installed the correct PTE. In such a case, the local TLB flush would be unnecessary overhead, but overall reduction of CPU synchronization overhead by not using IPTE is still expected to be beneficial. Reviewed-by:
Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by:
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Peter Xu authored
The current definition already collapse with the generic definition of vm_fault_reason. Move the private definitions to allocate bits from the top of uint so they won't collapse anymore. Signed-off-by:
Peter Xu <peterx@redhat.com> Link: https://lore.kernel.org/r/20230205231704.909536-4-peterx@redhat.comSigned-off-by:
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- 10 Feb, 2023 4 commits
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Randy Dunlap authored
Correct spelling problems for Documentation/s390/ as reported by codespell. Signed-off-by:
Randy Dunlap <rdunlap@infradead.org> Acked-by:
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Halil Pasic authored
Since commit 159491f3 ("s390/ap: rework assembler functions to use unions for in/out register variables") the function ap_qact() tries to grab the status from the wrong part of the register. Thus we always end up with zeros. Which is wrong, among others, because we detect failures via status.response_code. Signed-off-by:
Halil Pasic <pasic@linux.ibm.com> Reported-by:
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Halil Pasic authored
There function ap_aqic() tries to grab the status from the wrong part of the register. Thus we always end up with zeros. Which is wrong, among others, because we detect failures via status.response_code. Signed-off-by:
Janosch Frank <frankja@linux.ibm.com> Fixes: 159491f3 ("s390/ap: rework assembler functions to use unions for in/out register variables") Reviewed-by:
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Halil Pasic authored
The NIB is architecturally invalid if the address designates a storage location that is not installed or if it is zero. Signed-off-by:
Tony Krowiak <akrowiak@linux.ibm.com> Reviewed-by:
Pierre Morel <pmorel@linux.ibm.com> Signed-off-by:
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- 09 Feb, 2023 10 commits
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Heiko Carstens authored
This reverts commit cbc29f10. Get rid of the following smatch warnings: arch/s390/include/asm/mem_detect.h:86 get_mem_detect_end() error: uninitialized symbol 'end'. arch/s390/include/asm/mem_detect.h:86 get_mem_detect_end() error: uninitialized symbol 'end'. arch/s390/boot/vmem.c:256 setup_vmem() error: uninitialized symbol 'start'. arch/s390/boot/vmem.c:258 setup_vmem() error: uninitialized symbol 'end'. Note that there is no bug in the code. This is purely to silence smatch. Reported-by:
kernel test robot <lkp@intel.com> Reported-by:
Dan Carpenter <error27@gmail.com> Signed-off-by:
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Heiko Carstens authored
arch_cpu_idle_time() returns the idle time of any given cpu if it is in idle, or zero if not. All if this is racy and partially incorrect. Time stamps taken with store clock extended and store clock fast from different cpus are compared, while the architecture states that this is nothing which can be relied on (see Principles of Operation; Chapter 4, "Setting and Inspecting the Clock"). A more fundamental problem is that the timestamp when a cpu is leaving idle is taken early in the assembler part of the interrupt handler, and this value is only transferred many cycles later to the cpu's per-cpu idle data structure. This per cpu data structure is read by arch_cpu_idle() to tell for which period of time a remote cpu is idle: if only an idle_enter value is present, the assumed idle time of the cpu is calculated by taking a local timestamp and returning the difference of the local timestamp and the idle_enter value. This is potentially incorrect, since the remote cpu may have already left idle, but the taken timestamp may not have been transferred to the per-cpu data structure. This in turn means that too much idle time may be reported for a cpu, and a subsequent calculation of system idle time may result in a smaller value. Instead of coming up with even more complex code trying to fix this, just remove this code, and only account idle time of a cpu, after idle state is left. Another minor bug is that it is assumed that timestamps are non-zero, which is not necessarily the case for timestamps taken with store clock fast. This however is just a very minor problem, since this can only happen when the epoch increases. Reviewed-by:
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Heiko Carstens authored
Use simple assignments to access __vector128 members instead of hard to read casts. Signed-off-by: -
Heiko Carstens authored
Add 64 and 128 bit members to __vector128 struct in order to allow reading of the complete value, or the higher or lower part of vector register contents instead of having to use casts. Add an explicit __aligned(4) statement to avoid that the alignment of the structure changes from 4 to 8. This should make sure that no breakage happens because of this change. Reviewed-by:
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Heiko Carstens authored
The diag288_wdt watchdog driver is s390 specific. Document who is responsible for this driver. Signed-off-by: -
Vineeth Vijayan authored
Storage Class Memory driver support for s390 architecture has been there for a while. The original author of this work, Sebastian Ott has left IBM and I am taking over this module. Adding myself as the upstream maintainer for SCM on s390 architecture. Signed-off-by:
Vineeth Vijayan <vneethv@linux.ibm.com> Acked-by:
Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by:
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Heiko Carstens authored
arch_cpu_idle() is marked noinstr and therefore must only call functions which are also not instrumented. Make sure that cpu flag helper functions are always inlined to avoid that the compiler generates an out-of-line function for e.g. the call within arch_cpu_idle(). Reviewed-by:
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Heiko Carstens authored
linux-next commit ("cpuidle: tracing: Warn about !rcu_is_watching()") adds a new warning which hits on s390's arch_cpu_idle() function: RCU not on for: arch_cpu_idle+0x0/0x28 WARNING: CPU: 2 PID: 0 at include/linux/trace_recursion.h:162 arch_ftrace_ops_list_func+0x24c/0x258 Modules linked in: CPU: 2 PID: 0 Comm: swapper/2 Not tainted 6.2.0-rc6-next-20230202 #4 Hardware name: IBM 8561 T01 703 (z/VM 7.3.0) Krnl PSW : 0404d00180000000 00000000002b55c0 (arch_ftrace_ops_list_func+0x250/0x258) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 RI:0 EA:3 Krnl GPRS: c0000000ffffbfff 0000000080000002 0000000000000026 0000000000000000 0000037ffffe3a28 0000037ffffe3a20 0000000000000000 0000000000000000 0000000000000000 0000000000f4acf6 00000000001044f0 0000037ffffe3cb0 0000000000000000 0000000000000000 00000000002b55bc 0000037ffffe3bb8 Krnl Code: 00000000002b55b0: c02000840051 larl %r2,0000000001335652 00000000002b55b6: c0e5fff512d1 brasl %r14,0000000000157b58 #00000000002b55bc: af000000 mc 0,0 >00000000002b55c0: a7f4ffe7 brc 15,00000000002b558e 00000000002b55c4: 0707 bcr 0,%r7 00000000002b55c6: 0707 bcr 0,%r7 00000000002b55c8: eb6ff0480024 stmg %r6,%r15,72(%r15) 00000000002b55ce: b90400ef lgr %r14,%r15 Call Trace: [<00000000002b55c0>] arch_ftrace_ops_list_func+0x250/0x258 ([<00000000002b55bc>] arch_ftrace_ops_list_func+0x24c/0x258) [<0000000000f5f0fc>] ftrace_common+0x1c/0x20 [<00000000001044f6>] arch_cpu_idle+0x6/0x28 [<0000000000f4acf6>] default_idle_call+0x76/0x128 [<00000000001cc374>] do_idle+0xf4/0x1b0 [<00000000001cc6ce>] cpu_startup_entry+0x36/0x40 [<0000000000119d00>] smp_start_secondary+0x140/0x150 [<0000000000f5d2ae>] restart_int_handler+0x6e/0x90 Mark arch_cpu_idle() noinstr like all other architectures with CONFIG_ARCH_WANTS_NO_INSTR (should) have it to fix this. Reviewed-by: -
Heiko Carstens authored
There is no reason to do idle time accounting in arch_cpu_idle(). Do idle time accounting in account_idle_time_irq(), where it belongs to. The accounted values don't change between account_idle_time_irq() and arch_cpu_idle(); so the result is the same. Reviewed-by:
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Heiko Carstens authored
Signed-off-by:
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- 06 Feb, 2023 15 commits
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Alexander Egorenkov authored
Change naming of the internal diag288 helper functions to improve overall readability and reduce confusion: * Rename __diag288() to diag288(). * Get rid of the misnamed helper __diag288_lpar() that was used not only on LPARs but also zVM and KVM systems. * Rename __diag288_vm() to diag288_str(). Reviewed-by:
Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20230203073958.1585738-6-egorenar@linux.ibm.comSigned-off-by:
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Alexander Egorenkov authored
Call diag_stat_inc() from __diag288() to reduce code duplication. Reviewed-by:
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Alexander Egorenkov authored
Simplify and de-duplicate code by introducing a common single command buffer allocated once at initialization. Moreover, simplify the interface of __diag288_vm() by accepting ASCII strings as the command parameter and converting it to the EBCDIC format within the function itself. Reviewed-by:
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Alexander Egorenkov authored
Remove power management because s390 no longer supports hibernation since commit 39421627 ("s390: remove broken hibernate / power management support"). Reviewed-by:
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Alexander Egorenkov authored
Using register asm statements has been proven to be very error prone, especially when using code instrumentation where gcc may add function calls, which clobbers register contents in an unexpected way. Therefore, get rid of register asm statements in watchdog code, and make sure this bug class cannot happen. Moreover, remove the register r1 from the clobber list because this register is not changed by DIAG 288. Reviewed-by:
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Heiko Carstens authored
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Vasily Gorbik authored
Fixes: bb1520d5 ("s390/mm: start kernel with DAT enabled") Reviewed-by:
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Vasily Gorbik authored
Facilities setup has to be done after "facilities" command line option parsing, it might set extra or remove existing facilities bits for testing purposes. Fixes: bb1520d5 ("s390/mm: start kernel with DAT enabled") Reviewed-by:
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Vasily Gorbik authored
KASAN common code is able to handle memory hotplug and create KASAN shadow memory on a fly. Online memory ranges are available from mem_detect, use this information to avoid mapping KASAN shadow for standby memory. Reviewed-by:
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Vasily Gorbik authored
If kernel is build without KASAN support there is a chance that kernel image is going to be positioned by KASLR code to overlap with identity mapping page tables. When kernel is build with KASAN support enabled memory which is potentially going to be used for page tables and KASAN shadow mapping is accounted for in KASLR with the use of kasan_estimate_memory_needs(). Split this function and introduce vmem_estimate_memory_needs() to cover decompressor's vmem identity mapping page tables. Fixes: bb1520d5 ("s390/mm: start kernel with DAT enabled") Reviewed-by:
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Vasily Gorbik authored
Add a function to get online memory in total. It is supposed to be used in the decompressor as well as during early kernel startup. Reviewed-by:
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Vasily Gorbik authored
Introduce mem_detect_truncate() to cut any online memory ranges above established identity mapping size, so that mem_detect users wouldn't have to do it over and over again. Suggested-by:
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Vasily Gorbik authored
Allocation of mem_detect extended area was not considered neither in commit 9641b8cc ("s390/ipl: read IPL report at early boot") nor in commit b2d24b97 ("s390/kernel: add support for kernel address space layout randomization (KASLR)"). As a result mem_detect extended theoretically may overlap with ipl report or randomized kernel image position. But as mem_detect code will allocate extended area only upon exceeding 255 online regions (which should alternate with offline memory regions) it is not seen in practice. To make sure mem_detect extended area does not overlap with ipl report or randomized kernel position extend usage of "safe_addr". Make initrd handling and mem_detect extended area allocation code move it further right and make KASLR takes in into consideration as well. Fixes: 9641b8cc ("s390/ipl: read IPL report at early boot") Fixes: b2d24b97 ("s390/kernel: add support for kernel address space layout randomization (KASLR)") Reviewed-by:
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Vasily Gorbik authored
In case sclp_early_get_memsize() fails but diag260() succeeds make sure some sane value is returned. This error scenario is highly unlikely, but this change makes system able to boot in such case. Suggested-by:
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Heiko Carstens authored
Get rid of this sparse warning: arch/s390/kernel/diag.c:69:29: warning: symbol '__diag8c_tmp_amode31' was not declared. Should it be static? Fixes: fbaee746 ("s390/tty3270: add support for diag 8c") Signed-off-by:
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