- Oct 26, 2021
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Sven Schnelle authored
Currently s390 supports a fixed maximum command line length of 896 bytes. This isn't enough as some installers are trying to pass all configuration data via kernel command line, and even with zfcp alone it is easy to generate really long command lines. Therefore extend the command line to 4 kbytes. In the parm area where the command line is stored there is no indication of the maximum allowed length, so a new field which contains the maximum length is added. The parm area has always been initialized to zero, so with old kernels this field would read zero. This is important because tools like zipl could read this field. If it contains a number larger than zero zipl knows the maximum length that can be stored in the parm area, otherwise it must assume that it is booting a legacy kernel and only 896 bytes are available. The removing of trailing whitespace in head.S is also removed because code to do this is already present in setup_boot_command_line(). Signed-off-by:
Sven Schnelle <svens@linux.ibm.com> Reviewed-by:
Heiko Carstens <hca@linux.ibm.com> Signed-off-by:
Vasily Gorbik <gor@linux.ibm.com>
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Sven Schnelle authored
In preparation of adding support for command lines with variable sizes on s390, the check whether the new kernel image is at least HEAD_END bytes long isn't correct. Move the check to kexec_file_add_components() so we can get the size of the parm area and check the size there. The '.org HEAD_END' directive can now also be removed from head.S. This was used in the past to reserve space for the early sccb buffer, but with commit 9a5131b87cac1 ("s390/boot: move sclp early buffer from fixed address in asm to C") this is no longer required. Signed-off-by: -
Niklas Schnelle authored
Some applications map the same memory area for DMA multiple times while also mapping significant amounts of memory. With our current DMA code these applications will run out of DMA addresses after mapping half of the available memory because the number of DMA mappings is constrained by the number of concurrently active DMA addresses we support which in turn is limited by the minimum of hardware constraints and high_memory. Limiting the number of active DMA addresses to high_memory is only a heuristic to save memory used by the iommu_bitmap and DMA page tables however. This was added under the assumption that it rarely makes sense to DMA map more than system memory. To accommodate special applications which insist on double mapping, which works on other platforms, allow specifying a factor of how many times installed memory is available as DMA address space. Use 0 as a special value to apply no constraints beyond what hardware dictates at the expense of significantly more memory use. Reviewed-by:
Matthew Rosato <mjrosato@linux.ibm.com> Reviewed-by:
Pierre Morel <pmorel@linux.ibm.com> Signed-off-by:
Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by:
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Heiko Carstens authored
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Heiko Carstens authored
The generic version of strlcpy is identical to the architecure specific variant. Therefore use the generic variant. Signed-off-by:
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Heiko Carstens authored
Use generic strrchr instead of an optimized architecture specific variant. Performance of strrchr is not relevant for real life workloads, since the only user which may call this more frequently would be kbasename(). Suggested-by:
Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/lkml/CAHk-=whoe211F8ND-9hZvfnib0UA4gga8DZJ+YaBZNbE4fubdg@mail.gmail.com/ Signed-off-by:
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Harald Freudenberger authored
Slight rework of function __ap_revise_reserved() because of unused variable warning when build with W=1. This patch introduces an additional debug feature warning message when device_reprobe() returns with failure. However, the return value of __ap_revise_reserved() is still hard coded to 0 as this is a callback function to be used together with bus_for_each_dev() and thus the return value indicates to go on with the bus_for_each_dev() loop and not apport on a failure of something within this function. Signed-off-by:
Harald Freudenberger <freude@linux.ibm.com> Signed-off-by:
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Halil Pasic authored
Since commit 48720ba5 ("virtio/s390: use DMA memory for ccw I/O and classic notifiers") we were supposed to make sure that virtio_ccw_release_dev() completes before the ccw device and the attached dma pool are torn down, but unfortunately we did not. Before that commit it used to be OK to delay cleaning up the memory allocated by virtio-ccw indefinitely (which isn't really intuitive for guys used to destruction happens in reverse construction order), but now we trigger a BUG_ON if the genpool is destroyed before all memory allocated from it is deallocated. Which brings down the guest. We can observe this problem, when unregister_virtio_device() does not give up the last reference to the virtio_device (e.g. because a virtio-scsi attached scsi disk got removed without previously unmounting its previously mounted partition). To make sure that the genpool is only destroyed after all the necessary freeing is done let us take a reference on the ccw device on each ccw_device_dma_zalloc() and give it up on each ccw_device_dma_free(). Actually there are multiple approaches to fixing the problem at hand that can work. The upside of this one is that it is the safest one while remaining simple. We don't crash the guest even if the driver does not pair allocations and frees. The downside is the reference counting overhead, that the reference counting for ccw devices becomes more complex, in a sense that we need to pair the calls to the aforementioned functions for it to be correct, and that if we happen to leak, we leak more than necessary (the whole ccw device instead of just the genpool). Some alternatives to this approach are taking a reference in virtio_ccw_online() and giving it up in virtio_ccw_release_dev() or making sure virtio_ccw_release_dev() completes its work before virtio_ccw_remove() returns. The downside of these approaches is that these are less safe against programming errors. Cc: <stable@vger.kernel.org> # v5.3 Signed-off-by:
Halil Pasic <pasic@linux.ibm.com> Fixes: 48720ba5 ("virtio/s390: use DMA memory for ccw I/O and classic notifiers") Reported-by:
<bfu@redhat.com> Reviewed-by:
Vineeth Vijayan <vneethv@linux.ibm.com> Acked-by:
Cornelia Huck <cohuck@redhat.com> Signed-off-by:
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Tony Krowiak authored
Fixes the kernel-doc warnings in the following source files: * drivers/s390/crypto/vfio_ap_private.h * drivers/s390/crypto/vfio_ap_drv.c * drivers/s390/crypto/vfio_ap_ops.c Signed-off-by:
Tony Krowiak <akrowiak@linux.ibm.com> Signed-off-by:
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Heiko Carstens authored
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Harald Freudenberger authored
This patch introduces a new AP module option to be able to control if the ap bus code is using interrupts or not. By default if the interrupt support is available it is used. This option makes it possible to disable interrupt use even when interrupt support is available. It should be obvious that this option can't magically enable interrupt support when the hardware or hypervisor layer does not support AP interrupts. On the kernel command line use ap.useirq=0 or ap.useirq=1 to disable or enable (that's the default) interrupt use. Signed-off-by:
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Thomas Richter authored
Commit a029a4ea ("s390/cpumf: Allow concurrent access for CPU Measurement Counter Facility") added CPU Measurement counter facility access to multiple consumers. It allows concurrent access to the CPU Measurement counter facility via several perf_event_open() system call invocations and via ioctl() system call of device /dev/hwc. However the access via device /dev/hwc was exclusive, only one process was able to open this device. The patch removes this restriction. Now multiple invocations of lshwc can execute in parallel. They can access different CPUs and counter sets or CPUs and counter set can overlap. Signed-off-by:
Thomas Richter <tmricht@linux.ibm.com> Suggested-by:
Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by:
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Huilong Deng authored
Signed-off-by:
Huilong Deng <denghuilong@cdjrlc.com> Link: https://lore.kernel.org/r/20211017092057.24179-1-denghuilong@cdjrlc.com Signed-off-by:
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Sven Schnelle authored
The Breaking-Event-Address-Register (BEAR) stores the address of the last breaking event instruction. Breaking events are usually instructions that change the program flow - for example branches, and instructions that modify the address in the PSW like lpswe. This is useful for debugging wild branches, because one could easily figure out where the wild branch was originating from. What is problematic is that lpswe is considered a breaking event, and therefore overwrites BEAR on kernel exit. The BEAR enhancement facility adds new instructions that allow to save/restore BEAR and also an lpswey instruction that doesn't cause a breaking event. So we can save BEAR on kernel entry and restore it on exit to user space. Signed-off-by:
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Sven Schnelle authored
and replace all of the "__is_defined(CC_USING_EXPOLINE) && !nospec_disable" occurrences. Signed-off-by:
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Sven Schnelle authored
With the upcoming BEAR enhancements last_break isn't really unique, so rename it to pgm_last_break. This way it should be more obvious that this is the last_break value that is written by the hardware when a program check occurs. Signed-off-by:
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Sven Schnelle authored
Instead of using args[0] for the value of the last breaking event address register, add a member to make things more obvious. Signed-off-by:
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Alexander Gordeev authored
Provide physical addresses whenever the hardware interface expects it or a 32-bit value used for tracking. Variable sclp_early_sccb gets initialized in the decompressor and points to an address in physcal memory. Yet, it is used as virtual memory pointer and therefore should be converted. Note, the other two __bootdata variables sclp_info_sccb and sclp_info_sccb_valid contain plain data, but no pointers and do need any special care. Reviewed-by:
Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by:
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Alexander Gordeev authored
Variables initrd_start and initrd_end are expected to hold virtual memory pointers, not physical. Reviewed-by:
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Alexander Gordeev authored
memblock_reserve() function accepts physcal address of a memory block to be reserved, but provided with virtual memory pointers. Reviewed-by:
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Alexander Gordeev authored
Provide virtual memory pointer for system-information block. Reviewed-by:
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Alexander Gordeev authored
Virtual Console Function DIAGNOSE 8 accepts physical addresses of command and response strings. Reviewed-by:
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Alexander Gordeev authored
Instructions IPTE, IDTE and CRDTE accept Page-Table Origin as one of the arguments, but instead the pgtable virtual address is passed. Fix that and also update the crdte() prototype to conform to csp() and cspg() friends. Reviewed-by:
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Harald Freudenberger authored
This patch reworks all the debug feature invocations to be more uniform. All invocations now use the macro with the level already part of the macro name. All messages now start with %s filled with __func__ (well there are still some exceptions), and some message text has been shortened or reworked. There is no functional code touched with this patch. Signed-off-by:
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Harald Freudenberger authored
When a queue is switched to soft offline during heavy load and later switched to soft online again and now used, it may be that the caller is blocked forever in the ioctl call. The failure occurs because there is a pending reply after the queue(s) have been switched to offline. This orphaned reply is received when the queue is switched to online and is accidentally counted for the outstanding replies. So when there was a valid outstanding reply and this orphaned reply is received it counts as the outstanding one thus dropping the outstanding counter to 0. Voila, with this counter the receive function is not called any more and the real outstanding reply is never received (until another request comes in...) and the ioctl blocks. The fix is simple. However, instead of readjusting the counter when an orphaned reply is detected, I check the queue status for not empty and compare this to the outstanding counter. So if the queue is not empty then the counter must not drop to 0 but at least have a value of 1. Signed-off-by:
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Vasily Gorbik authored
pci and string functions changes on features depend on changes from the fixes branch. * fixes: s390: add Alexander Gordeev as reviewer s390: fix strrchr() implementation vfio-ccw: step down as maintainer KVM: s390: remove myself as reviewer s390/pci: fix zpci_zdev_put() on reserve bpf, s390: Fix potential memory leak about jit_data Signed-off-by:
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- Oct 19, 2021
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Heiko Carstens authored
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Heiko Carstens authored
Add s390 support for ftrace direct call samples, which also enables ftrace direct call selftests within ftrace selftests. Acked-by:
Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by:
Steven Rostedt (VMware) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20211012133802.2460757-5-hca@linux.ibm.com Signed-off-by:
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Heiko Carstens authored
Add HAVE_SAMPLE_FTRACE_DIRECT config option which can be selected by architectures which have support for ftrace direct call samples. Acked-by:
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Heiko Carstens authored
Make STACK_FRAME_OVERHEAD available via asm-offsets.h. This allows to add s390 specific asm code to e.g. ftrace samples, without requiring to add random header files, which might cause all sort of problems on other architectures. asm-offsets.h can be assumed to be non-problematic. Acked-by:
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Heiko Carstens authored
This is the s390 variant of commit 562955fe ("ftrace/x86: Add register_ftrace_direct() for custom trampolines"). Acked-by:
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- Oct 13, 2021
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Heiko Carstens authored
Alexander Gordeev will help reviewing s390 code. Acked-by:
Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by:
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- Oct 12, 2021
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Roberto Sassu authored
Fix two problems found in the strrchr() implementation for s390 architectures: evaluate empty strings (return the string address instead of NULL, if '\0' is passed as second argument); evaluate the first character of non-empty strings (the current implementation stops at the second). Fixes: 1da177e4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reported-by: Heiko Carstens <hca@linux.ibm.com> (incorrect behavior with empty strings) Signed-off-by:
Roberto Sassu <roberto.sassu@huawei.com> Link: https://lore.kernel.org/r/20211005120836.60630-1-roberto.sassu@huawei.com Signed-off-by:
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Cornelia Huck authored
I currently don't have time to act as vfio-ccw maintainer anymore, but I trust that I leave it in capable hands. Signed-off-by:
Eric Farman <farman@linux.ibm.com> Acked-by:
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Cornelia Huck authored
I currently don't have time anymore to review KVM/s390 code. Signed-off-by:
Janosch Frank <frankja@linux.ibm.com> Acked-by:
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Andy Shevchenko authored
Use string_upper() from string helper module instead of open coded variant. Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20211001130201.72545-1-andriy.shevchenko@linux.intel.com [hca@linux.ibm.com: removed hunk which converts extmem.c] Signed-off-by:
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Heiko Carstens authored
Add regs_get_kernel_argument() which returns Nth argument of a function call. This enables ftrace kprobe events to access kernel function arguments via $argN syntax. This is the s390 variant of commit a823c35f ("arm64: ptrace: Add function argument access API"). Acked-by:
Steffen Maier <maier@linux.ibm.com> Signed-off-by:
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Heiko Carstens authored
This is the s390 variant of commit 9855c462 ("selftests/ftrace: Add ppc support for kprobe args tests"). Acked-by:
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Heiko Carstens authored
Reported-by:
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Heiko Carstens authored
ftrace_regs_caller is an alias to ftrace_caller - making ftrace_caller quite heavyweight. Split the function and provide an ftrace_caller implementation which comes with fewer instructions. Especially getting rid of 'stosm' on each function entry should help here, e.g. to have less performance impact on live patched functions. Signed-off-by:
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