kernel/drivers/s390/char/sclp_cmd.c, branch linux-6.9.y

s390/mm: implement MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE notifiers

2024-02-22T00:00:02Z

MEM_PREPARE_ONLINE memory notifier makes memory block physical accessible via sclp assign command. The notifier ensures self-contained memory maps are accessible and hence enabling the "memmap on memory" on s390. MEM_FINISH_OFFLINE memory notifier shifts the memory block to an inaccessible state via sclp unassign command. Implementation considerations: * When MHP_MEMMAP_ON_MEMORY is disabled, the system retains the old behavior. This means the memory map is allocated from default memory. * If MACHINE_HAS_EDAT1 is unavailable, MHP_MEMMAP_ON_MEMORY is automatically disabled. This ensures that vmemmap pagetables do not consume additional memory from the default memory allocator. * The MEM_GOING_ONLINE notifier has been modified to perform no operation, as MEM_PREPARE_ONLINE already executes the sclp assign command. * The MEM_CANCEL_ONLINE/MEM_OFFLINE notifier now performs no operation, as MEM_FINISH_OFFLINE already executes the sclp unassign command. Link: https://lkml.kernel.org/r/20240108132747.3238763-5-sumanthk@linux.ibm.com Reviewed-by: Gerald Schaefer Reviewed-by: David Hildenbrand Signed-off-by: Sumanth Korikkar Cc: Alexander Gordeev Cc: Aneesh Kumar K.V Cc: Anshuman Khandual Cc: Heiko Carstens Cc: Michal Hocko Cc: Oscar Salvador Cc: Vasily Gorbik Signed-off-by: Andrew Morton

s390/sclp: remove unhandled memory notifier type

2024-02-22T00:00:02Z

Remove memory notifier types which are unhandled by s390. Unhandled memory notifier types are covered by default case. Link: https://lkml.kernel.org/r/20240108132747.3238763-4-sumanthk@linux.ibm.com Suggested-by: Alexander Gordeev Reviewed-by: David Hildenbrand Signed-off-by: Sumanth Korikkar Cc: Aneesh Kumar K.V Cc: Anshuman Khandual Cc: Gerald Schaefer Cc: Heiko Carstens Cc: Michal Hocko Cc: Oscar Salvador Cc: Vasily Gorbik Signed-off-by: Andrew Morton

s390/sclp: handle default case in sclp memory notifier

2023-10-25T13:08:29Z

When new memory notifier types are added in common code and unimplemented on s390, return success instead of EINVAL return code. This prevents breakage when new memory notifier types are added. Reviewed-by: Heiko Carstens Signed-off-by: Sumanth Korikkar Signed-off-by: Vasily Gorbik

s390/ctlreg: rename ctl_reg.h to ctlreg.h

2023-09-19T11:26:56Z

Rename ctl_reg.h to ctlreg.h so it matches not only ctlreg.c but also other control register related function, union, and structure names, which all come with a ctlreg prefix. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/mm: remove redundant check against VMEM_MAX_PHYS

2023-07-24T10:12:23Z

The value of ident_map_size could never exceed the value of vmemmap as secured by setup_kernel_memory_layout() function: /* make sure identity map doesn't overlay with vmemmap */ ident_map_size = min(ident_map_size, vmemmap_start); Since VMEM_MAX_PHYS macro is set to vmemmap and a newly added range is checked against ident_map_size in add_memory_merged() function anyway, the check against VMEM_MAX_PHYS is redundant. Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev Signed-off-by: Heiko Carstens

s390/sclp: replace zero-length array with flexible-array member

2023-04-13T15:36:29Z

There are numerous patches which convert zero-length arrays with a flexible-array member. Convert the remaining s390 occurrences. Suggested-by: Gustavo A. R. Silva Link: https://github.com/KSPP/linux/issues/78 Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html Signed-off-by: Heiko Carstens 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/dump: introduce boot data 'oldmem_data'

2021-07-27T07:39:16Z

The new boot data struct shall replace global variables OLDMEM_BASE and OLDMEM_SIZE. It is initialized in the decompressor and passed to the decompressed kernel. In comparison to the old solution, this one doesn't access data at fixed physical addresses which will become important when the decompressor becomes relocatable. Signed-off-by: Alexander Egorenkov Acked-by: Heiko Carstens Signed-off-by: Heiko Carstens

s390/sclp: Remove memory hotplug power management support

2021-06-18T14:41:20Z

Power management support was removed for s390 with commit 394216275c7d ("s390: remove broken hibernate / power management support"). Remove leftover sclp memory hotplug-related power management code. Acked-by: Heiko Carstens Signed-off-by: Peter Oberparleiter Signed-off-by: Vasily Gorbik

s390: unify identity mapping limits handling

2020-11-20T18:19:10Z

Currently we have to consider too many different values which in the end only affect identity mapping size. These are: 1. max_physmem_end - end of physical memory online or standby. Always <= end of the last online memory block (get_mem_detect_end()). 2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the kernel is able to support. 3. "mem=" kernel command line option which limits physical memory usage. 4. OLDMEM_BASE which is a kdump memory limit when the kernel is executed as crash kernel. 5. "hsa" size which is a memory limit when the kernel is executed during zfcp/nvme dump. Through out kernel startup and run we juggle all those values at once but that does not bring any amusement, only confusion and complexity. Unify all those values to a single one we should really care, that is our identity mapping size. Signed-off-by: Vasily Gorbik Reviewed-by: Alexander Gordeev Acked-by: Heiko Carstens Signed-off-by: Heiko Carstens