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

s390/extable: move EX_TABLE define to asm-extable.h

2022-03-07T23:33:00Z

Follow arm64 and riscv and move the EX_TABLE define to asm-extable.h which is a lot less generic than the current linkage.h. Also make sure that all files which contain EX_TABLE usages actually include the new header file. This should make sure that the files always compile and there won't be any random compile breakage due to other header file dependencies. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390: rename dma section to amode31

2021-08-05T12:10:53Z

The dma section name is confusing, since the code which resides within that section has nothing to do with direct memory access. Instead the limitation is that the code has to run in 31 bit addressing mode, and therefore has to reside below 2GB. So the name was chosen since ZONE_DMA is the same region. To reduce confusion rename the section to amode31, which hopefully describes better what this is about. Note: this will also change vmcoreinfo strings - SDMA=... gets renamed to SAMODE31=... - EDMA=... gets renamed to EAMODE31=... Acked-by: Vasily Gorbik Reviewed-by: Alexander Egorenkov Signed-off-by: Heiko Carstens

s390: replace deprecated CPU-hotplug functions

2021-08-05T12:10:53Z

The functions get_online_cpus() and put_online_cpus() have been deprecated during the CPU hotplug rework. They map directly to cpus_read_lock() and cpus_read_unlock(). Replace deprecated CPU-hotplug functions with the official version. The behavior remains unchanged. Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20210803141621.780504-5-bigeasy@linutronix.de Signed-off-by: Heiko Carstens

s390/boot: move dma sections from decompressor to decompressed kernel

2021-07-27T07:39:17Z

This change simplifies the task of making the decompressor relocatable. The decompressor's image contains special DMA sections between _sdma and _edma. This DMA segment is loaded at boot as part of the decompressor and then simply handed over to the decompressed kernel. The decompressor itself never uses it in any way. The primary reason for this is the need to keep the aforementioned DMA segment below 2GB which is required by architecture, and because the decompressor is always loaded at a fixed low physical address, it is guaranteed that the DMA region will not cross the 2GB memory limit. If the DMA region had been placed in the decompressed kernel, then KASLR would make this guarantee impossible to fulfill or it would be restricted to the first 2GB of memory address space. This commit moves all DMA sections between _sdma and _edma from the decompressor's image to the decompressed kernel's image. The complete DMA region is placed in the init section of the decompressed kernel and immediately relocated below 2GB at start-up before it is needed by other parts of the decompressed kernel. The relocation of the DMA region happens even if the decompressed kernel is already located below 2GB in order to keep the first implementation simple. The relocation should not have any noticeable impact on boot time because the DMA segment is only a couple of pages. After relocating the DMA sections, the kernel has to fix all references which point into it. In order to automate this, place all variables pointing into the DMA sections in a special .dma.refs section. All such variables must be defined using the new __dma_ref macro. Only variables containing addresses within the DMA sections must be placed in the new .dma.refs section. Furthermore, move the initialization of control registers from the decompressor to the decompressed kernel because some control registers reference tables that must be placed in the DMA data section to guarantee that their addresses are below 2G. Because the decompressed kernel relocates the DMA sections at startup, the content of control registers CR2, CR5 and CR15 must be updated with new addresses after the relocation. The decompressed kernel initializes all control registers early at boot and then updates the content of CR2, CR5 and CR15 as soon as the DMA relocation has occurred. This practically reverts the commit a80313ff91ab ("s390/kernel: introduce .dma sections"). Signed-off-by: Alexander Egorenkov Acked-by: Heiko Carstens Signed-off-by: Heiko Carstens

s390/diag: use register pair instead of register asm

2021-06-18T14:41:21Z

Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/diag: convert to use DEFINE_SEQ_ATTRIBUTE macro

2020-09-17T12:11:03Z

Use DEFINE_SEQ_ATTRIBUTE macro to simplify the code. Signed-off-by: Liu Shixin Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/ftrace: fix potential crashes when switching tracers

2020-04-22T14:20:55Z

Switching tracers include instruction patching. To prevent that a instruction is patched while it's read the instruction patching is done in stop_machine 'context'. This also means that any function called during stop_machine must not be traced. Thus add 'notrace' to all functions called within stop_machine. Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls") Fixes: 38f2c691a4b3 ("s390: improve wait logic of stop_machine") Fixes: 4ecf0a43e729 ("processor: get rid of cpu_relax_yield") Signed-off-by: Philipp Rudo Signed-off-by: Vasily Gorbik

s390/diag: fix display of diagnose call statistics

2020-03-25T11:39:37Z

Show the full diag statistic table and not just parts of it. The issue surfaced in a KVM guest with a number of vcpus defined smaller than NR_DIAG_STAT. Fixes: 1ec2772e0c3c ("s390/diag: add a statistic for diagnose calls") Cc: stable@vger.kernel.org Signed-off-by: Michael Mueller Reviewed-by: Heiko Carstens Signed-off-by: Vasily Gorbik

s390/kernel: introduce .dma sections

2019-04-29T08:47:10Z

With a relocatable kernel that could reside at any place in memory, code and data that has to stay below 2 GB needs special handling. This patch introduces .dma sections for such text, data and ex_table. The sections will be part of the decompressor kernel, so they will not be relocated and stay below 2 GB. Their location is passed over to the decompressed / relocated kernel via the .boot.preserved.data section. The duald and aste for control register setup also need to stay below 2 GB, so move the setup code from arch/s390/kernel/head64.S to arch/s390/boot/head.S. The duct and linkage_stack could reside above 2 GB, but their content has to be preserved for the decompresed kernel, so they are also moved into the .dma section. The start and end address of the .dma sections is added to vmcoreinfo, for crash support, to help debugging in case the kernel crashed there. Signed-off-by: Gerald Schaefer Reviewed-by: Philipp Rudo Signed-off-by: Martin Schwidefsky

s390/setup: set control program code via diag 318

2019-01-28T14:58:53Z

The s390x diagnose 318 instruction sets the control program name code (CPNC) and control program version code (CPVC) to provide useful information regarding the OS during debugging. The CPNC is explicitly set to 4 to indicate a Linux/KVM environment. The CPVC is a 7-byte value containing: - 3-byte Linux version code, currently set to 0 - 3-byte unique value, currently set to 0 - 1-byte trailing null Signed-off-by: Collin Walling Acked-by: Janosch Frank Acked-by: Heiko Carstens Reviewed-by: David Hildenbrand Reviewed-by: Cornelia Huck Message-Id: <1544135405-22385-2-git-send-email-walling@linux.ibm.com> [set version code to 0 until the structure is fully defined] Signed-off-by: Christian Borntraeger Signed-off-by: Martin Schwidefsky