kernel.git/arch/s390/kernel/smp.c, branch linux-5.18.y

s390/smp: use physical address for SIGP_SET_PREFIX command

2022-03-27T20:18:39Z

Signal processor SIGP_SET_PREFIX command expects physical address of the lowcore to be installed, but instead the virtual address is provided. 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: Vasily Gorbik

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/smp: cleanup control register update routines

2022-03-27T20:18:39Z

Get rid of duplicate code and redundant data. Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Vasily Gorbik

s390/smp: cleanup target CPU callback starting

2022-03-27T20:18:39Z

Macro mem_assign_absolute() is used to initialize a target CPU lowcore callback parameters. But despite the macro name it writes to the absolute lowcore only if the target CPU is offline. In case the CPU is online the macro does implicitly write to the normal memory. That behaviour is correct, but extremely subtle. Sacrifice few program bits in favour of clarity and distinguish between online vs offline CPUs and normal vs absolute lowcore pointer. 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/smp: sort out physical vs virtual pointers usage

2022-03-01T20:05:10Z

With commit 5789284710aa ("s390/smp: reallocate IPL CPU lowcore") virtual addresses are wrongly passed to memblock_free_late() and SPX instructions on IPL CPU reinitialization. Note: this does not fix a bug currently, since virtual and physical addresses are identical. Fixes: 5789284710aa ("s390/smp: reallocate IPL CPU lowcore") Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Vasily Gorbik

s390/maccess: fix semantics of memcpy_real() and its callers

2022-02-09T21:56:04Z

There is a confusion with regard to the source address of memcpy_real() and calling functions. While the declared type for a source assumes a virtual address, in fact it always called with physical address of the source. This confusion led to bugs in copy_oldmem_kernel() and copy_oldmem_user() functions, where __pa() macro applied mistakenly to physical addresses. It does not lead to a real issue, since virtual and physical addresses are currently the same. Fix both the bugs and memcpy_real() prototype by making type of source address consistent to the function name and the way it actually used. Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Vasily Gorbik

s390: remove invalid email address of Heiko Carstens

2022-02-06T22:31:29Z

Remove my old invalid email address which can be found in a couple of files. Instead of updating it, just remove my contact data completely from source files. We have git and other tools which allow to figure out who is responsible for what with recent contact data. Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/crash_dump: fix virtual vs physical address handling

2021-12-20T09:21:55Z

Signal processor STORE STATUS requires a physical address where register contents are supposed to be written to, however the kernel must read the data via the corresponding virtual address. Also the allocated save_area, where register contents are copied to, resides in virtual address space. Fix this by using proper __pa() conversion, or correct memblock_alloc() invocation. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens

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