linux-dev/arch/s390/kernel/setup.c, branch linus/master

s390/smp: sort out physical vs virtual CPU0 lowcore pointer

2022-04-25T11:54:13Z

SPX instruction called from set_prefix() expects physical address of the lowcore to be installed, but instead the virtual address is passed. Note: this does not fix a bug currently, since virtual and physical addresses are identical. Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390/maccess: rework absolute lowcore accessors

2022-03-27T20:18:39Z

Macro mem_assign_absolute() is able to access the whole memory, but is only used and makes sense when updating the absolute lowcore. Instead, introduce get_abs_lowcore() and put_abs_lowcore() macros that limit access to absolute lowcore addresses only. Suggested-by: Heiko Carstens Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Vasily Gorbik

s390: raise minimum supported machine generation to z10

2022-03-10T14:58:17Z

Machine generations up to z9 (released in May 2006) have been officially out of service for several years now (z9 end of service - January 31, 2019). No distributions build kernels supporting those old machine generations anymore, except Debian, which seems to pick the oldest supported generation. The team supporting Debian on s390 has been notified about the change. Raising minimum supported machine generation to z10 helps to reduce maintenance cost and effectively remove code, which is not getting enough testing coverage due to lack of older hardware and distributions support. Besides that this unblocks some optimization opportunities and allows to use wider instruction set in asm files for future features implementation. Due to this change spectre mitigation and usercopy implementations could be drastically simplified and many newer instructions could be converted from ".insn" encoding to instruction names. Acked-by: Ilya Leoshkevich Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/setup: preserve memory at OLDMEM_BASE and OLDMEM_SIZE

2022-03-01T19:41:28Z

We need to preserve the values at OLDMEM_BASE and OLDMEM_SIZE which are used by zgetdump in case when kdump crashes. In that case zgetdump will attempt to read OLDMEM_BASE and OLDMEM_SIZE in order to find out where the memory range [0 - OLDMEM_SIZE] belonging to the production kernel is. Fixes: f1a546947431 ("s390/setup: don't reserve memory that occupied decompressor's head") Cc: stable@vger.kernel.org # 5.15+ Signed-off-by: Alexander Egorenkov Acked-by: Vasily Gorbik Signed-off-by: Vasily Gorbik

s390/nmi: disable interrupts on extended save area update

2021-12-16T18:58:07Z

Updating of the pointer to machine check extended save area on the IPL CPU needs the lowcore protection to be disabled. Disable interrupts while the protection is off to avoid unnoticed writes to the lowcore. Suggested-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390/setup: re-arrange memblock setup

2021-11-16T11:29:19Z

- Avoid using ULONG_MAX in memblock_remove, it has no functional change but makes memblock_dbg output a range which makes sense. - Actually finish memblock memory setup before doing amode31/cr/uv setup. - Move memblock_dump_all() debug output after memblock memory setup is complete. This gives us final "memory" regions if they were trimmed due to addressing limits and still "physmem" regions as original info which came from mem_detect. Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/setup: avoid using memblock_enforce_memory_limit

2021-11-16T11:29:18Z

There is a difference in how architectures treat "mem=" option. For some that is an amount of online memory, for s390 and x86 this is the limiting max address. Some memblock api like memblock_enforce_memory_limit() take limit argument and explicitly treat it as the size of online memory, and use __find_max_addr to convert it to an actual max address. Current s390 usage: memblock_enforce_memory_limit(memblock_end_of_DRAM()); yields different results depending on presence of memory holes (offline memory blocks in between online memory). If there are no memory holes limit == max_addr in memblock_enforce_memory_limit() and it does trim online memory and reserved memory regions. With memory holes present it actually does nothing. Since we already use memblock_remove() explicitly to trim online memory regions to potential limit (think mem=, kdump, addressing limits, etc.) drop the usage of memblock_enforce_memory_limit() altogether. Trimming reserved regions should not be required, since we now use memblock_set_current_limit() to limit allocations and any explicit memory reservations above the limit is an actual problem we should not hide. Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens

s390/setup: avoid reserving memory above identity mapping

2021-11-16T11:29:18Z

Such reserved memory region, if not cleaned up later causes problems when memblock_free_all() is called to release free pages to the buddy allocator and those reserved regions are carried over to reserve_bootmem_region() which marks the pages as PageReserved. Instead use memblock_set_current_limit() to make sure memblock allocations do not go over identity mapping (which could happen when "mem=" option is used or during kdump). Cc: stable@vger.kernel.org Fixes: 73045a08cf55 ("s390: unify identity mapping limits handling") Reported-by: Gerald Schaefer Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Heiko Carstens

Merge tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2021-11-06T21:48:06Z

Pull s390 updates from Vasily Gorbik: - Add support for ftrace with direct call and ftrace direct call samples. - Add support for kernel command lines longer than current 896 bytes and make its length configurable. - Add support for BEAR enhancement facility to improve last breaking event instruction tracking. - Add kprobes sanity checks and testcases to prevent kprobe in the mid of an instruction. - Allow concurrent access to /dev/hwc for the CPUMF users. - Various ftrace / jump label improvements. - Convert unwinder tests to KUnit. - Add s390_iommu_aperture kernel parameter to tweak the limits on concurrently usable DMA mappings. - Add ap.useirq AP module option which can be used to disable interrupt use. - Add add_disk() error handling support to block device drivers. - Drop arch specific and use generic implementation of strlcpy and strrchr. - Several __pa/__va usages fixes. - Various cio, crypto, pci, kernel doc and other small fixes and improvements all over the code. [ Merge fixup as per https://lore.kernel.org/all/YXAqZ%2FEszRisunQw@osiris/ ] * tag 's390-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (63 commits) s390: make command line configurable s390: support command lines longer than 896 bytes s390/kexec_file: move kernel image size check s390/pci: add s390_iommu_aperture kernel parameter s390/spinlock: remove incorrect kernel doc indicator s390/string: use generic strlcpy s390/string: use generic strrchr s390/ap: function rework based on compiler warning s390/cio: make ccw_device_dma_* more robust s390/vfio-ap: s390/crypto: fix all kernel-doc warnings s390/hmcdrv: fix kernel doc comments s390/ap: new module option ap.useirq s390/cpumf: Allow multiple processes to access /dev/hwc s390/bitops: return true/false (not 1/0) from bool functions s390: add support for BEAR enhancement facility s390: introduce nospec_uses_trampoline() s390: rename last_break to pgm_last_break s390/ptrace: add last_break member to pt_regs s390/sclp: sort out physical vs virtual pointers usage s390/setup: convert start and end initrd pointers to virtual ...

memblock: allow to specify flags with memblock_add_node()

2021-11-06T20:30:42Z

We want to specify flags when hotplugging memory. Let's prepare to pass flags to memblock_add_node() by adjusting all existing users. Note that when hotplugging memory the system is already up and running and we might have concurrent memblock users: for example, while we're hotplugging memory, kexec_file code might search for suitable memory regions to place kexec images. It's important to add the memory directly to memblock via a single call with the right flags, instead of adding the memory first and apply flags later: otherwise, concurrent memblock users might temporarily stumble over memblocks with wrong flags, which will be important in a follow-up patch that introduces a new flag to properly handle add_memory_driver_managed(). Link: https://lkml.kernel.org/r/20211004093605.5830-4-david@redhat.com Acked-by: Geert Uytterhoeven Acked-by: Heiko Carstens Signed-off-by: David Hildenbrand Acked-by: Shahab Vahedi [arch/arc] Reviewed-by: Mike Rapoport Cc: "Aneesh Kumar K . V" Cc: Arnd Bergmann Cc: Christian Borntraeger Cc: Eric Biederman Cc: Huacai Chen Cc: Jianyong Wu Cc: Jiaxun Yang Cc: Michal Hocko Cc: Oscar Salvador Cc: Thomas Bogendoerfer Cc: Vasily Gorbik Cc: Vineet Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds