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| * | s390/fpu: decrease stack usage for some casesHeiko Carstens2024-02-168-42/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel_fpu structure has a quite large size of 520 bytes. In order to reduce stack footprint introduce several kernel fpu structures with different and also smaller sizes. This way every kernel fpu user must use the correct variant. A compile time check verifies that the correct variant is used. There are several users which use only 16 instead of all 32 vector registers. For those users the new kernel_fpu_16 structure with a size of only 266 bytes can be used. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: let fpu_vlm() and fpu_vstm() return number of registersHeiko Carstens2024-02-161-8/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let fpu_vlm() and fpu_vstm() macros return the number of registers saved / loaded. This is helpful to read easy to read code in case there are several subsequent fpu_vlm() or fpu_vstm() calls: __vector128 *vxrs = .... vxrs += fpu_vstm(0, 15, vxrs); vxrs += fpu_vstm(16, 31, vxrs); Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: remove anonymous union from struct fpuHeiko Carstens2024-02-165-109/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The anonymous union within struct fpu contains a floating point register array and a vector register array. Given that the vector register is always present remove the floating point register array. For configurations without vector registers save the floating point register contents within their corresponding vector register location. This allows to remove the union, and also to simplify ptrace and perf code. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: remove regs member from struct fpuHeiko Carstens2024-02-164-10/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | KVM was the only user which modified the regs pointer in struct fpu. Remove the pointer and convert the rest of the core fpu code to directly access the save area embedded within struct fpu. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/kvm: convert to regular kernel fpu userHeiko Carstens2024-02-165-26/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KVM modifies the kernel fpu's regs pointer to its own area to implement its custom version of preemtible kernel fpu context. With general support for preemptible kernel fpu context there is no need for the extra complexity in KVM code anymore. Therefore convert KVM to a regular kernel fpu user. In particular this means that all TIF_FPU checks can be removed, since the fpu register context will never be changed by other kernel fpu users, and also the fpu register context will be restored if a thread is preempted. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: make kernel fpu context preemptibleHeiko Carstens2024-02-164-13/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | Make the kernel fpu context preemptible. Add another fpu structure to the thread_struct, and use it to save and restore the kernel fpu context if its task uses fpu registers when it is preempted. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: change type of fpu mask from u32 to intHeiko Carstens2024-02-163-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | Change type of fpu mask consistently from u32 to int. This is a prerequisite to make the kernel fpu usage preemptible. Upcoming code uses __atomic* ops which work with int pointers. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: rename save_fpu_regs() to save_user_fpu_regs(), etcHeiko Carstens2024-02-1613-102/+102
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rename save_fpu_regs(), load_fpu_regs(), and struct thread_struct's fpu member to save_user_fpu_regs(), load_user_fpu_regs(), and ufpu. This way the function and variable names reflect for which context they are supposed to be used. This large and trivial conversion is a prerequisite for making the kernel fpu usage preemptible. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: convert FPU CIF flag to regular TIF flagHeiko Carstens2024-02-169-16/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The FPU state, as represented by the CIF_FPU flag reflects the FPU state of a task, not the CPU it is running on. Therefore convert the flag to a regular TIF flag. This removes the magic in switch_to() where a save_fpu_regs() call for the currently (previous) running task sets the per-cpu CIF_FPU flag, which is required to restore FPU register contents of the next task, when it returns to user space. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: convert __kernel_fpu_begin()/__kernel_fpu_end() to CHeiko Carstens2024-02-163-96/+75
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the rather large __kernel_fpu_begin()/__kernel_fpu_end() inline assemblies to C. The C variant is much more readable, and this also allows to get rid of the non-obvious usage of KERNEL_VXR_* constants within the inline assemblies. E.g. "tmll %[m],6" correlates with the two bits set in KERNEL_VXR_LOW. If the corresponding defines would be changed, the inline assembles would break in a subtle way. Therefore convert to C, use the proper defines, and allow the compiler to generate code using the (hopefully) most efficient instructions. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: provide and use vlm and vstm inline assembliesHeiko Carstens2024-02-163-27/+88
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of open-coding vlm and vstm inline assemblies at several locations, provide an fpu_* function for each instruction, and use them in the new save_vx_regs() and load_vx_regs() helper functions. Note that "O" and "R" inline assembly operand modifiers are used in order to pass the displacement and base register of the memory operands to the existing VLM and VSTM macros. The two operand modifiers are not available for clang. Therefore provide two variants of each inline assembly. The clang variant always uses and clobbers general purpose register 1, like in the previous inline assemblies, so it can be used as base register with a zero displacement. This generates slightly less efficient code, but can be removed as soon as clang has support for the used operand modifiers. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: provide and use lfpc, sfpc, and stfpc inline assembliesHeiko Carstens2024-02-163-10/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of open-coding lfpc, sfpc, and stfpc inline assemblies at several locations, provide an fpu_* function for each instruction and use the function instead. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: provide and use ld and std inline assembliesHeiko Carstens2024-02-163-72/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | Deduplicate the 64 ld and std inline assemblies. Provide an fpu inline assembly for both instructions, and use them in the new save_fp_regs() and load_fp_regs() helper functions. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: use lfpc instead of sfpc instructionHeiko Carstens2024-02-162-9/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only user of sfpc_safe() needs to read the new fpc register value from memory before it is set with sfpc. Avoid this indirection and use lfpc, which reads the new value from memory. Also add the "fpu_" prefix to have a common name space for fpu related inline assemblies, and provide memory access instrumentation. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: add documentation about fpu helper functionsHeiko Carstens2024-02-161-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | Add documentation which describes what the fpu helper functions are good for, and why they should be used. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: move, rename, and merge header filesHeiko Carstens2024-02-1631-147/+130
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move, rename, and merge the fpu and vx header files. This way fpu header files have a consistent naming scheme (fpu*.h). Also get rid of the fpu subdirectory and move header files to asm directory, so that all fpu and vx header files can be found at the same location. Merge internal.h header file into other header files, since the internal helpers are used at many locations. so those helper functions are really not internal. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: various coding style changesHeiko Carstens2024-02-164-27/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | Address various checkpatch warnings, adjust whitespace, and try to increase readability. This is just preparation, in order to avoid that subsequent patches contain any distracting drive-by coding style changes. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: use KERNEL_VXR_LOW instead of KERNEL_VXR_V0V7Heiko Carstens2024-02-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use KERNEL_VXR_LOW instead of KERNEL_VXR_V0V7 for configurations without vector registers in order to decide if floating point registers need to be saved and restored. Kernel FPU areas which use floating point registers are supposed to use the KERNEL_FPR mask, however users may also open-code this and specify KERNEL_VXR_V0V7 and/or KERNEL_VXR_V8V15. If only KERNEL_VXR_V8V15 is specified floating point registers wouldn't be saved and restored. Improve this and check for both bits. There are currently no users where this would fix a bug. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/nmi: remove register validation codeHeiko Carstens2024-02-162-122/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the historic machine check handler code which validates registers. Registers are automatically validated as part of the machine check handling sequence (see Principles of Operation, Machine-Check Handling chapter, Validation). Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: improve description of RXB macroHeiko Carstens2024-02-161-4/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The v1, v2, v3, and v4 parameters of the RXB macro are a bit misleading, since the reader can assume that the parameters always correlate with the instructions format fields V1, V2, V3, and V4 as defined in the Principles of Operation. This is not the case for a couple of instructions, therefore improve the description of the macro. Suggested by Jens Remus, who also provided the improved description. Suggested-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: fix VLGV macroHeiko Carstens2024-02-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The VLGV macro generates the VLGV instruction and has a vr parameter which correlates to the V3 vector register field of the instruction (bits 12-15). Due to its position in the VRS-c instruction format of the VLGV instruction, this field correlates to the second bit of the RXB byte of the instruction (see Principles of Operation, Chapter "Vector Overview and Support Instructions"). Within the VLGV macro the MRXBOPC macro is used to generate the RXB field of the instruction. The usage of the MRXBOPC macro is incorrect, since the vector register number is passed as third parameter (which correlates to the first bit of the RXB byte), while it should be passed as fourth parameter (second bit of the RXB byte). In result an incorrect instruction would be generated if the VLGV macro would be used for vector register numbers larger than 15. Fix this and pass the vector register number as fourth parameter. Currently there are no users within the kernel which use the macro in a way that broken code would be generated. Reviewed-by: Jens Remus <jremus@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/zcrypt: add debug possibility for CCA and EP11 messagesHarald Freudenberger2024-02-161-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces dynamic debug hexdump invocation possibilities to be able to: - dump an CCA or EP11 CPRB request as early as possible when received via ioctl from userspace but after the ap message has been collected together. - dump an CCA or EP11 CPRB reply short before it is transferred via ioctl into userspace. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/ap: add debug possibility for AP messagesHarald Freudenberger2024-02-161-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch introduces two dynamic debug hexdump invocation possibilities to be able to a) dump an AP message immediately before it goes into the firmware queue and b) dump a fresh from the firmware queue received AP message. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/pkey: introduce dynamic debugging for pkeyHarald Freudenberger2024-02-161-24/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch replaces all the s390 debug feature calls with debug level by dynamic debug calls pr_debug. These calls are much more flexible and each single invocation can get enabled/disabled at runtime wheres the s390 debug feature debug calls have only one knob - enable or disable all in one bunch. This patch follows a similar change for the AP bus and zcrypt device driver code. All this code uses dynamic debugging with pr_debug and friends for emitting debug traces now. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/pkey: harmonize pkey s390 debug feature callsHarald Freudenberger2024-02-161-91/+97
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cleanup and harmonize the s390 debug feature calls and defines for the pkey module to be similar to the debug feature as it is used in the zcrypt device driver and AP bus. More or less only renaming but no functional changes. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/zcrypt: introduce dynamic debugging for AP and zcrypt codeHarald Freudenberger2024-02-167-85/+89
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch replaces all the s390 debug feature calls with debug level by dynamic debug calls pr_debug. These calls are much more flexible and each single invocation can get enabled/disabled at runtime wheres the s390 debug feature debug calls have only one knob - enable or disable all in one bunch. The benefit is especially significant with high frequency called functions like the AP bus scan. In most debugging scenarios you don't want and need them, but sometimes it is crucial to know exactly when and how long the AP bus scan took. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/zcrypt: harmonize debug feature calls and definesHarald Freudenberger2024-02-166-193/+156
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch harmonizes the calls and defines around the s390 debug feature as it is used in the AP bus and zcrypt device driver code. More or less cleanup and renaming, no functional changes. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/setup: fix virtual vs physical address confusionGerald Schaefer2024-02-161-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix virtual vs physical address confusion. This does not fix a bug since virtual and physical address spaces are currently the same. /proc/iomem should report the physical address ranges, so use __pa_symbol() for resource registration, similar to other architectures. Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: don't allow CONFIG_COMPAT with LD=ld.lldNathan Chancellor2024-02-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building 'ARCH=s390 defconfig compat.config' with GCC and LD=ld.lld, there is an error when attempting to link the compat vDSO: ld.lld: error: unknown emulation: elf_s390 make[4]: *** [arch/s390/kernel/vdso32/Makefile:48: arch/s390/kernel/vdso32/vdso32.so.dbg] Error 1 Much like clang, ld.lld only supports the 64-bit s390 emulation. Add a dependency on not using LLD to CONFIG_COMPAT to avoid breaking the build with this toolchain combination. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240214-s390-compat-lld-dep-v1-1-abf1f4b5e514@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/vdso: remove unused ENTRY in linker scriptsHeiko Carstens2024-02-142-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When linking vdso64.so.dbg with ld.lld, there is a warning about not finding _start for the starting address: ld.lld: warning: cannot find entry symbol _start; not setting start address Fix this by removing the unused ENTRY in both vdso linker scripts. See commit e247172854a5 ("powerpc/vdso: Remove unused ENTRY in linker scripts"), which solved the same problem for powerpc, for further details. Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/bug: remove entry size from __bug_table sectionHeiko Carstens2024-02-141-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit e21f8baf8d9a ("s390/bug: add entry size to the __bug_table section") changed the __EMIT_BUG() inline assembly to emit mergeable __bug_table entries. This is at least currently not needed, but causes problems with the upcoming s390 ld.lld support: ld.lld: error: drivers/nvme/host/fc.o:(__bug_table): writable SHF_MERGE section is not supported Therefore revert the change for now. Reported-by: Nathan Chancellor <nathan@kernel.org> Closes: https://lore.kernel.org/all/20240207-s390-lld-and-orphan-warn-v1-0-8a665b3346ab@kernel.org/ Suggested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: link vmlinux with '-z notext'Nathan Chancellor2024-02-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ld.bfd defaults to '-z notext' (although it is customizable with the '--enable-textrel-check' configure option) but ld.lld defaults to '-z text', which causes issues with building the kernel due to the presence of dynamic relocations in sections that are not writable. ld.lld: error: relocation R_390_64 cannot be used against local symbol; recompile with -fPIC Add '-z notext' to avoid these errors, as this is expected, which matches other architectures. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Reviewed-by: Fangrui Song <maskray@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-11-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: select CONFIG_ARCH_WANT_LD_ORPHAN_WARNNathan Chancellor2024-02-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that all sections have been properly accounted for in the s390 linker scripts, select CONFIG_ARCH_WANT_LD_ORPHAN_WARN so that '--orphan-handling' is added to LDFLAGS to catch any future sections that are added without being described in linker scripts. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-10-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: vmlinux.lds.S: handle commonly discarded sectionsNathan Chancellor2024-02-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are several series of warnings from the various discardable sections that the kernel adds for build purposes that are not needed at runtime: s390-linux-ld: warning: orphan section `.export_symbol' from `arch/s390/boot/decompressor.o' being placed in section `.export_symbol' s390-linux-ld: warning: orphan section `.discard.addressable' from `arch/s390/boot/decompressor.o' being placed in section `.discard.addressable' s390-linux-ld: warning: orphan section `.modinfo' from `arch/s390/boot/decompressor.o' being placed in section `.modinfo' include/asm-generic/vmlinux.lds.h has a macro for easily discarding these sections across the kernel named COMMON_DISCARDS, use it to clear up the warnings. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-9-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: vmlinux.lds.S: handle ELF required sectionsNathan Chancellor2024-02-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there is a warning around the '.comment' section for each file in arch/s390/boot s390-linux-ld: warning: orphan section `.comment' from `arch/s390/boot/als.o' being placed in section `.comment' s390-linux-ld: warning: orphan section `.comment' from `arch/s390/boot/startup.o' being placed in section `.comment' s390-linux-ld: warning: orphan section `.comment' from `arch/s390/boot/physmem_info.o' being placed in section `.comment' include/asm-generic/vmlinux.lds.h has a macro for required ELF sections not related to debugging named ELF_DETAILS, use it to clear up the warnings. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-8-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: vmlinux.lds.S: handle DWARF debug sectionsNathan Chancellor2024-02-141-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are several series of warnings for each file in arch/s390/boot due to the boot linker script not handling the DWARF debug sections: s390-linux-ld: warning: orphan section `.debug_line' from `arch/s390/boot/head.o' being placed in section `.debug_line' s390-linux-ld: warning: orphan section `.debug_info' from `arch/s390/boot/head.o' being placed in section `.debug_info' s390-linux-ld: warning: orphan section `.debug_abbrev' from `arch/s390/boot/head.o' being placed in section `.debug_abbrev' s390-linux-ld: warning: orphan section `.debug_aranges' from `arch/s390/boot/head.o' being placed in section `.debug_aranges' s390-linux-ld: warning: orphan section `.debug_str' from `arch/s390/boot/head.o' being placed in section `.debug_str' include/asm-generic/vmlinux.lds.h has a macro for DWARF debug sections named DWARF_DEBUG, use it to clear up the warnings. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Reviewed-by: Fangrui Song <maskray@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-7-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: vmlinux.lds.S: handle '.rela' sectionsNathan Chancellor2024-02-141-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are several warnings from arch/s390/boot/head.o due to the unhandled presence of '.rela' sections: s390-linux-ld: warning: orphan section `.rela.iplt' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.head.text' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.got' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.data' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.data.rel.ro' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.iplt' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.head.text' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.got' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.data' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' s390-linux-ld: warning: orphan section `.rela.data.rel.ro' from `arch/s390/boot/head.o' being placed in section `.rela.dyn' These sections are unneeded for the decompressor and they are not emitted in the binary currently. In a manner similar to other architectures, coalesce the sections into '.rela.dyn' and ensure it is zero sized, which is a safe/tested approach versus full discard. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-6-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: vmlinux.lds.S: handle '.init.text'Nathan Chancellor2024-02-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there is a warning about the presence of an '.init.text' section in arch/s390/boot: s390-linux-ld: warning: orphan section `.init.text' from `arch/s390/boot/sclp_early_core.o' being placed in section `.init.text' arch/s390/boot/sclp_early_core.c includes a file from the main kernel build, which picks up a usage of '__init' somewhere. For the decompressed image, this section can just be coalesced into '.text'. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-5-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: vmlinux.lds.S: explicitly keep various sectionsNathan Chancellor2024-02-141-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are some warnings around certain ELF sections: s390-linux-ld: warning: orphan section `.dynstr' from `arch/s390/kernel/head64.o' being placed in section `.dynstr' s390-linux-ld: warning: orphan section `.dynamic' from `arch/s390/kernel/head64.o' being placed in section `.dynamic' s390-linux-ld: warning: orphan section `.hash' from `arch/s390/kernel/head64.o' being placed in section `.hash' s390-linux-ld: warning: orphan section `.gnu.hash' from `arch/s390/kernel/head64.o' being placed in section `.gnu.hash' Explicitly keep those sections like other architectures when CONFIG_RELOCATABLE is enabled, which is always true for s390. [hca@linux.ibm.com: keep sections instead of discarding] Signed-off-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-4-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: vmlinux.lds.S: explicitly handle '.got' and '.plt' sectionsNathan Chancellor2024-02-142-0/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are a lot of warnings around the GOT and PLT sections: s390-linux-ld: warning: orphan section `.plt' from `arch/s390/kernel/head64.o' being placed in section `.plt' s390-linux-ld: warning: orphan section `.got' from `arch/s390/kernel/head64.o' being placed in section `.got' s390-linux-ld: warning: orphan section `.got.plt' from `arch/s390/kernel/head64.o' being placed in section `.got.plt' s390-linux-ld: warning: orphan section `.iplt' from `arch/s390/kernel/head64.o' being placed in section `.iplt' s390-linux-ld: warning: orphan section `.igot.plt' from `arch/s390/kernel/head64.o' being placed in section `.igot.plt' s390-linux-ld: warning: orphan section `.iplt' from `arch/s390/boot/head.o' being placed in section `.iplt' s390-linux-ld: warning: orphan section `.igot.plt' from `arch/s390/boot/head.o' being placed in section `.igot.plt' s390-linux-ld: warning: orphan section `.got' from `arch/s390/boot/head.o' being placed in section `.got' Currently, only the '.got' section is actually emitted in the final binary. In a manner similar to other architectures, put the '.got' section near the '.data' section and coalesce the PLT sections, checking that the final section is zero sized, which is a safe/tested approach versus full discard. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-3-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390: vmlinux.lds.S: handle '.data.rel' sections explicitlyNathan Chancellor2024-02-141-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CONFIG_LD_ORPHAN_WARN after selecting CONFIG_ARCH_HAS_LD_ORPHAN_WARN, there are a lot of warnings around '.data.rel' sections: s390-linux-ld: warning: orphan section `.data.rel' from `kernel/sched/build_utility.o' being placed in section `.data.rel' s390-linux-ld: warning: orphan section `.data.rel.local' from `kernel/sched/build_utility.o' being placed in section `.data.rel.local' s390-linux-ld: warning: orphan section `.data.rel.ro' from `kernel/sched/build_utility.o' being placed in section `.data.rel.ro' s390-linux-ld: warning: orphan section `.data.rel.ro.local' from `kernel/sched/build_utility.o' being placed in section `.data.rel.ro.local' Describe these in vmlinux.lds.S so there is no more warning and the sections are placed consistently between linkers. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-2-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/boot: add support for CONFIG_LD_ORPHAN_WARNNathan Chancellor2024-02-141-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | arch/s390/boot/vmlinux uses a different linker script and build rules than the main vmlinux, so the '--orphan-handling' flag is not applied to it. Add support for '--orphan-handling' so that all sections are properly described in the linker script, which helps eliminate bugs between linker implementations having different orphan section heuristics. Signed-off-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Justin Stitt <justinstitt@google.com> Link: https://lore.kernel.org/r/20240207-s390-lld-and-orphan-warn-v1-1-8a665b3346ab@kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/switch_to: use generic header fileHeiko Carstens2024-02-1211-48/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the switch_to() implementation to process.c and use the generic switch_to.h header file instead, like some other architectures. This addresses also the oddity that the old switch_to() implementation assigns the return value of __switch_to() to 'prev' instead of 'last', like it should. Remove also all includes of switch_to.h from C files, except process.c. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/acrs: cleanup access register handlingHeiko Carstens2024-02-1210-21/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | save_access_regs() and restore_access_regs() are only available by including switch_to.h. This is done by a couple of C files, which have nothing to do with switch_to(), but only need these functions. Move both functions to a new header file and improve the implementation: - Get rid of typedef - Add memory access instrumentation support - Use long displacement instructions lamy/stamy instead of lam/stam - all current users end up with better code because of this Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/extmem: fix virtual vs physical address confusionAlexander Gordeev2024-02-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Fix virtual vs physical address confusion. This does not fix a bug since virtual and physical address spaces are currently the same. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/fpu: make use of __uninitialized macroHeiko Carstens2024-02-095-5/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Code sections in s390 specific kernel code which use floating point or vector registers all come with a 520 byte stack variable to save already in use registers, if required. With INIT_STACK_ALL_PATTERN or INIT_STACK_ALL_ZERO enabled this variable will always be initialized on function entry in addition to saving register contents, which contradicts the intention (performance improvement) of such code sections. Therefore provide a DECLARE_KERNEL_FPU_ONSTACK() macro which provides struct kernel_fpu variables with an __uninitialized attribute, and convert all existing code to use this. This way only this specific type of stack variable will not be initialized, regardless of config options. Reviewed-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20240205154844.3757121-3-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | Compiler Attributes: Add __uninitialized macroHeiko Carstens2024-02-091-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With INIT_STACK_ALL_PATTERN or INIT_STACK_ALL_ZERO enabled the kernel will be compiled with -ftrivial-auto-var-init=<...> which causes initialization of stack variables at function entry time. In order to avoid the performance impact that comes with this users can use the "uninitialized" attribute to prevent such initialization. Therefore provide the __uninitialized macro which can be used for cases where INIT_STACK_ALL_PATTERN or INIT_STACK_ALL_ZERO is enabled, but only selected variables should not be initialized. Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Link: https://lore.kernel.org/r/20240205154844.3757121-2-hca@linux.ibm.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/vfio-ap: make matrix_bus constRicardo B. Marliere2024-02-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the driver core can properly handle constant struct bus_type, move the matrix_bus variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net> Acked-by: Halil Pasic <pasic@linux.ibm.com> Reviewed-by: Anthony Krowiak <akrowiak@linux.ibm.com> Reviewed-by: "Jason J. Herne" <jjherne@linux.ibm.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240203-bus_cleanup-s390-v1-6-ac891afc7282@marliere.net Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/ap: make ap_bus_type constRicardo B. Marliere2024-02-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the driver core can properly handle constant struct bus_type, move the ap_bus_type variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net> Reviewed-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240203-bus_cleanup-s390-v1-5-ac891afc7282@marliere.net Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| * | s390/cio: make scm_bus_type constRicardo B. Marliere2024-02-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the driver core can properly handle constant struct bus_type, move the scm_bus_type variable to be a constant structure as well, placing it into read-only memory which can not be modified at runtime. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20240203-bus_cleanup-s390-v1-4-ac891afc7282@marliere.net Signed-off-by: Heiko Carstens <hca@linux.ibm.com>