linux-dev/Documentation/powerpc, branch linus/master

powerpc: Enable the DAWR on POWER9 DD2.3 and above

2022-05-22T05:59:53Z

The hardware bug in POWER9 preventing use of the DAWR was fixed in DD2.3. Set the CPU_FTR_DAWR feature bit on these newer systems to start using it again, and update the documentation accordingly. The CPU features for DD2.3 are currently determined by "DD2.2 or later" logic. In adding DD2.3 as a discrete case for the first time here, I'm carrying the quirks of DD2.2 forward to keep all behavior outside of this DAWR change the same. This leaves the assessment and potential removal of those quirks on DD2.3 for later. Signed-off-by: Reza Arbab Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220503170152.23412-1-arbab@linux.ibm.com

powerpc: Book3S 64-bit outline-only KASAN support

2022-05-22T05:58:29Z

Implement a limited form of KASAN for Book3S 64-bit machines running under the Radix MMU, supporting only outline mode. - Enable the compiler instrumentation to check addresses and maintain the shadow region. (This is the guts of KASAN which we can easily reuse.) - Require kasan-vmalloc support to handle modules and anything else in vmalloc space. - KASAN needs to be able to validate all pointer accesses, but we can't instrument all kernel addresses - only linear map and vmalloc. On boot, set up a single page of read-only shadow that marks all iomap and vmemmap accesses as valid. - Document KASAN in powerpc docs. Background ---------- KASAN support on Book3S is a bit tricky to get right: - It would be good to support inline instrumentation so as to be able to catch stack issues that cannot be caught with outline mode. - Inline instrumentation requires a fixed offset. - Book3S runs code with translations off ("real mode") during boot, including a lot of generic device-tree parsing code which is used to determine MMU features. [ppc64 mm note: The kernel installs a linear mapping at effective address c000...-c008.... This is a one-to-one mapping with physical memory from 0000... onward. Because of how memory accesses work on powerpc 64-bit Book3S, a kernel pointer in the linear map accesses the same memory both with translations on (accessing as an 'effective address'), and with translations off (accessing as a 'real address'). This works in both guests and the hypervisor. For more details, see s5.7 of Book III of version 3 of the ISA, in particular the Storage Control Overview, s5.7.3, and s5.7.5 - noting that this KASAN implementation currently only supports Radix.] - Some code - most notably a lot of KVM code - also runs with translations off after boot. - Therefore any offset has to point to memory that is valid with translations on or off. One approach is just to give up on inline instrumentation. This way boot-time checks can be delayed until after the MMU is set is up, and we can just not instrument any code that runs with translations off after booting. Take this approach for now and require outline instrumentation. Previous attempts allowed inline instrumentation. However, they came with some unfortunate restrictions: only physically contiguous memory could be used and it had to be specified at compile time. Maybe we can do better in the future. [paulus@ozlabs.org - Rebased onto 5.17. Note that a kernel with CONFIG_KASAN=y will crash during boot on a machine using HPT translation because not all the entry points to the generic KASAN code are protected with a call to kasan_arch_is_ready().] Originally-by: Balbir Singh # ppc64 out-of-line radix version Signed-off-by: Daniel Axtens Signed-off-by: Paul Mackerras [mpe: Update copyright year and comment formatting] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/YoTE69OQwiG7z+Gu@cleo

kasan: Document support on 32-bit powerpc

2022-05-22T05:58:29Z

KASAN is supported on 32-bit powerpc and the docs should reflect this. Suggested-by: Christophe Leroy Signed-off-by: Daniel Axtens Signed-off-by: Paul Mackerras Reviewed-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/YoTEnMLrnd64j0w5@cleo

powerpc/doc: Fix htmldocs errors

2021-08-26T14:56:34Z

Fix make htmldocs related errors with the newly added associativity.rst doc file. Reported-by: Stephen Rothwell Tested-by: Stephen Rothwell # build test Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210825042447.106219-1-aneesh.kumar@linux.ibm.com

powerpc/pseries: Add support for FORM2 associativity

2021-08-13T12:04:27Z

PAPR interface currently supports two different ways of communicating resource grouping details to the OS. These are referred to as Form 0 and Form 1 associativity grouping. Form 0 is the older format and is now considered deprecated. This patch adds another resource grouping named FORM2. Signed-off-by: Daniel Henrique Barboza Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210812132223.225214-6-aneesh.kumar@linux.ibm.com

powerpc/64s/syscall: Use pt_regs.trap to distinguish syscall ABI difference between sc and scv syscalls

2021-05-20T14:58:03Z

The sc and scv 0 system calls have different ABI conventions, and ptracers need to know which system call type is being used if they want to look at the syscall registers. Document that pt_regs.trap can be used for this, and fix one in-tree user to work with scv 0 syscalls. Fixes: 7fa95f9adaee ("powerpc/64s: system call support for scv/rfscv instructions") Cc: stable@vger.kernel.org # v5.9+ Reported-by: "Dmitry V. Levin" Suggested-by: "Dmitry V. Levin" Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210520111931.2597127-1-npiggin@gmail.com

Merge tag 'powerpc-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2021-04-30T19:22:28Z

Pull powerpc updates from Michael Ellerman: - Enable KFENCE for 32-bit. - Implement EBPF for 32-bit. - Convert 32-bit to do interrupt entry/exit in C. - Convert 64-bit BookE to do interrupt entry/exit in C. - Changes to our signal handling code to use user_access_begin/end() more extensively. - Add support for time namespaces (CONFIG_TIME_NS) - A series of fixes that allow us to reenable STRICT_KERNEL_RWX. - Other smaller features, fixes & cleanups. Thanks to Alexey Kardashevskiy, Andreas Schwab, Andrew Donnellan, Aneesh Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Bixuan Cui, Cédric Le Goater, Chen Huang, Chris Packham, Christophe Leroy, Christopher M. Riedl, Colin Ian King, Dan Carpenter, Daniel Axtens, Daniel Henrique Barboza, David Gibson, Davidlohr Bueso, Denis Efremov, dingsenjie, Dmitry Safonov, Dominic DeMarco, Fabiano Rosas, Ganesh Goudar, Geert Uytterhoeven, Geetika Moolchandani, Greg Kurz, Guenter Roeck, Haren Myneni, He Ying, Jiapeng Chong, Jordan Niethe, Laurent Dufour, Lee Jones, Leonardo Bras, Li Huafei, Madhavan Srinivasan, Mahesh Salgaonkar, Masahiro Yamada, Nathan Chancellor, Nathan Lynch, Nicholas Piggin, Oliver O'Halloran, Paul Menzel, Pu Lehui, Randy Dunlap, Ravi Bangoria, Rosen Penev, Russell Currey, Santosh Sivaraj, Sebastian Andrzej Siewior, Segher Boessenkool, Shivaprasad G Bhat, Srikar Dronamraju, Stephen Rothwell, Thadeu Lima de Souza Cascardo, Thomas Gleixner, Tony Ambardar, Tyrel Datwyler, Vaibhav Jain, Vincenzo Frascino, Xiongwei Song, Yang Li, Yu Kuai, and Zhang Yunkai. * tag 'powerpc-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (302 commits) powerpc/signal32: Fix erroneous SIGSEGV on RT signal return powerpc: Avoid clang uninitialized warning in __get_user_size_allowed powerpc/papr_scm: Mark nvdimm as unarmed if needed during probe powerpc/kvm: Fix build error when PPC_MEM_KEYS/PPC_PSERIES=n powerpc/kasan: Fix shadow start address with modules powerpc/kernel/iommu: Use largepool as a last resort when !largealloc powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs powerpc/44x: fix spelling mistake in Kconfig "varients" -> "variants" powerpc/iommu: Annotate nested lock for lockdep powerpc/iommu: Do not immediately panic when failed IOMMU table allocation powerpc/iommu: Allocate it_map by vmalloc selftests/powerpc: remove unneeded semicolon powerpc/64s: remove unneeded semicolon powerpc/eeh: remove unneeded semicolon powerpc/selftests: Add selftest to test concurrent perf/ptrace events powerpc/selftests/perf-hwbreak: Add testcases for 2nd DAWR powerpc/selftests/perf-hwbreak: Coalesce event creation code powerpc/selftests/ptrace-hwbreak: Add testcases for 2nd DAWR powerpc/configs: Add IBMVNIC to some 64-bit configs selftests/powerpc: Add uaccess flush test ...

Documentation/powerpc: Add proper links for manual and tests

2021-04-20T04:22:23Z

The links that are mentioned in this document are no longer valid. So changed the proper links for NXGZIP user manual and test cases. Reported-by: Bulent Abali Signed-off-by: Haren Myneni Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/08511c1e92ac239f20ac88c73c59d1f8cf02e6ad.camel@linux.ibm.com

powerpc/papr_scm: Implement support for H_SCM_FLUSH hcall

2021-04-14T13:04:07Z

Add support for ND_REGION_ASYNC capability if the device tree indicates 'ibm,hcall-flush-required' property in the NVDIMM node. Flush is done by issuing H_SCM_FLUSH hcall to the hypervisor. If the flush request failed, the hypervisor is expected to to reflect the problem in the subsequent nvdimm H_SCM_HEALTH call. This patch prevents mmap of namespaces with MAP_SYNC flag if the nvdimm requires an explicit flush[1]. References: [1] https://github.com/avocado-framework-tests/avocado-misc-tests/blob/master/memory/ndctl.py.data/map_sync.c Signed-off-by: Shivaprasad G Bhat Reviewed-by: Aneesh Kumar K.V [mpe: Use unsigned long / long instead of uint64_t/int64_t] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/161703936121.36.7260632399582101498.stgit@e1fbed493c87

docs: powerpc: Fix misspellings and grammar errors

2021-03-31T19:50:59Z

Reported-by: Hulk Robot Signed-off-by: He Ying Acked-by: Michael Ellerman Link: https://lore.kernel.org/r/20210326100853.173586-1-heying24@huawei.com Signed-off-by: Jonathan Corbet