linux-dev/arch/powerpc/include/asm/atomic.h, branch linus/master

powerpc/atomics: Remove atomic_inc()/atomic_dec() and friends

2021-11-30T00:45:57Z

Now that atomic_add() and atomic_sub() handle immediate operands, atomic_inc() and atomic_dec() have no added value compared to the generic fallback which calls atomic_add(1) and atomic_sub(1). Also remove atomic_inc_not_zero() which fallsback to atomic_add_unless() which itself fallsback to atomic_fetch_add_unless() which now handles immediate operands. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/0bc64a2f18726055093dbb2e479cefc60a409cfd.1632236981.git.christophe.leroy@csgroup.eu

powerpc/atomics: Use immediate operand when possible

2021-11-30T00:45:57Z

Today we get the following code generation for atomic operations: c001bb2c: 39 20 00 01 li r9,1 c001bb30: 7d 40 18 28 lwarx r10,0,r3 c001bb34: 7d 09 50 50 subf r8,r9,r10 c001bb38: 7d 00 19 2d stwcx. r8,0,r3 c001c7a8: 39 40 00 01 li r10,1 c001c7ac: 7d 00 18 28 lwarx r8,0,r3 c001c7b0: 7c ea 42 14 add r7,r10,r8 c001c7b4: 7c e0 19 2d stwcx. r7,0,r3 By allowing GCC to choose between immediate or regular operation, we get: c001bb2c: 7d 20 18 28 lwarx r9,0,r3 c001bb30: 39 49 ff ff addi r10,r9,-1 c001bb34: 7d 40 19 2d stwcx. r10,0,r3 -- c001c7a4: 7d 40 18 28 lwarx r10,0,r3 c001c7a8: 39 0a 00 01 addi r8,r10,1 c001c7ac: 7d 00 19 2d stwcx. r8,0,r3 For "and", the dot form has to be used because "andi" doesn't exist. For logical operations we use unsigned 16 bits immediate. For arithmetic operations we use signed 16 bits immediate. On pmac32_defconfig, it reduces the text by approx another 8 kbytes. Signed-off-by: Christophe Leroy Acked-by: Segher Boessenkool Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/2ec558d44db8045752fe9dbd29c9ba84bab6030b.1632236981.git.christophe.leroy@csgroup.eu

powerpc/asm: Remove UPD_CONSTR after GCC 4.9 removal

2021-10-08T13:15:59Z

UPD_CONSTR was previously a preprocessor define for an old GCC 4.9 inline asm bug with m<> constraints. Fixes: 6563139d90ad ("powerpc: remove GCC version check for UPD_CONSTR") Suggested-by: Nathan Chancellor Suggested-by: Christophe Leroy Suggested-by: Michael Ellerman Signed-off-by: Nick Desaulniers Reviewed-by: Nathan Chancellor Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210914161712.2463458-1-ndesaulniers@google.com

powerpc: Use lwarx/ldarx directly instead of PPC_LWARX/LDARX macros

2021-08-25T03:35:49Z

Force the eh flag at 0 on PPC32. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1fc81f07cabebb875b963e295408cc3dd38c8d85.1614674882.git.christophe.leroy@csgroup.eu

locking/atomic: powerpc: move to ARCH_ATOMIC

2021-05-26T11:20:52Z

We'd like all architectures to convert to ARCH_ATOMIC, as once all architectures are converted it will be possible to make significant cleanups to the atomics headers, and this will make it much easier to generically enable atomic functionality (e.g. debug logic in the instrumented wrappers). As a step towards that, this patch migrates powerpc to ARCH_ATOMIC. The arch code provides arch_{atomic,atomic64,xchg,cmpxchg}*(), and common code wraps these with optional instrumentation to provide the regular functions. While atomic_try_cmpxchg_lock() is not part of the common atomic API, it is given an `arch_` prefix for consistency. Signed-off-by: Mark Rutland Cc: Benjamin Herrenschmidt Cc: Boqun Feng Cc: Michael Ellerman Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Will Deacon Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20210525140232.53872-28-mark.rutland@arm.com

powerpc: Fix update form addressing in inline assembly

2020-12-04T11:13:19Z

In several places, inline assembly uses the "%Un" modifier to enable the use of instruction with update form addressing, but the associated "<>" constraint is missing. As mentioned in previous patch, this fails with gcc 4.9, so "<>" can't be used directly. Use UPD_CONSTR macro everywhere %Un modifier is used. Signed-off-by: Christophe Leroy Reviewed-by: Segher Boessenkool Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/62eab5ca595485c192de1765bdac099f633a21d0.1603358942.git.christophe.leroy@csgroup.eu

Merge tag 'powerpc-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2020-08-07T17:33:50Z

Pull powerpc updates from Michael Ellerman: - Add support for (optionally) using queued spinlocks & rwlocks. - Support for a new faster system call ABI using the scv instruction on Power9 or later. - Drop support for the PROT_SAO mmap/mprotect flag as it will be unsupported on Power10 and future processors, leaving us with no way to implement the functionality it requests. This risks breaking userspace, though we believe it is unused in practice. - A bug fix for, and then the removal of, our custom stack expansion checking. We now allow stack expansion up to the rlimit, like other architectures. - Remove the remnants of our (previously disabled) topology update code, which tried to react to NUMA layout changes on virtualised systems, but was prone to crashes and other problems. - Add PMU support for Power10 CPUs. - A change to our signal trampoline so that we don't unbalance the link stack (branch return predictor) in the signal delivery path. - Lots of other cleanups, refactorings, smaller features and so on as usual. Thanks to: Abhishek Goel, Alastair D'Silva, Alexander A. Klimov, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Balamuruhan S, Bharata B Rao, Bill Wendling, Bin Meng, Cédric Le Goater, Chris Packham, Christophe Leroy, Christoph Hellwig, Daniel Axtens, Dan Williams, David Lamparter, Desnes A. Nunes do Rosario, Erhard F., Finn Thain, Frederic Barrat, Ganesh Goudar, Gautham R. Shenoy, Geoff Levand, Greg Kurz, Gustavo A. R. Silva, Hari Bathini, Harish, Imre Kaloz, Joel Stanley, Joe Perches, John Crispin, Jordan Niethe, Kajol Jain, Kamalesh Babulal, Kees Cook, Laurent Dufour, Leonardo Bras, Li RongQing, Madhavan Srinivasan, Mahesh Salgaonkar, Mark Cave-Ayland, Michal Suchanek, Milton Miller, Mimi Zohar, Murilo Opsfelder Araujo, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nayna Jain, Nicholas Piggin, Oliver O'Halloran, Palmer Dabbelt, Pedro Miraglia Franco de Carvalho, Philippe Bergheaud, Pingfan Liu, Pratik Rajesh Sampat, Qian Cai, Qinglang Miao, Randy Dunlap, Ravi Bangoria, Sachin Sant, Sam Bobroff, Sandipan Das, Santosh Sivaraj, Satheesh Rajendran, Shirisha Ganta, Sourabh Jain, Srikar Dronamraju, Stan Johnson, Stephen Rothwell, Thadeu Lima de Souza Cascardo, Thiago Jung Bauermann, Tom Lane, Vaibhav Jain, Vladis Dronov, Wei Yongjun, Wen Xiong, YueHaibing. * tag 'powerpc-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (337 commits) selftests/powerpc: Fix pkey syscall redefinitions powerpc: Fix circular dependency between percpu.h and mmu.h powerpc/powernv/sriov: Fix use of uninitialised variable selftests/powerpc: Skip vmx/vsx/tar/etc tests on older CPUs powerpc/40x: Fix assembler warning about r0 powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric powerpc/papr_scm: Fetch nvdimm performance stats from PHYP cpuidle: pseries: Fixup exit latency for CEDE(0) cpuidle: pseries: Add function to parse extended CEDE records cpuidle: pseries: Set the latency-hint before entering CEDE selftests/powerpc: Fix online CPU selection powerpc/perf: Consolidate perf_callchain_user_[64|32]() powerpc/pseries/hotplug-cpu: Remove double free in error path powerpc/pseries/mobility: Add pr_debug() for device tree changes powerpc/pseries/mobility: Set pr_fmt() powerpc/cacheinfo: Warn if cache object chain becomes unordered powerpc/cacheinfo: Improve diagnostics about malformed cache lists powerpc/cacheinfo: Use name@unit instead of full DT path in debug messages powerpc/cacheinfo: Set pr_fmt() powerpc: fix function annotations to avoid section mismatch warnings with gcc-10 ...

locking/atomic: Move ATOMIC_INIT into linux/types.h

2020-07-29T14:14:18Z

This patch moves ATOMIC_INIT from asm/atomic.h into linux/types.h. This allows users of atomic_t to use ATOMIC_INIT without having to include atomic.h as that way may lead to header loops. Signed-off-by: Herbert Xu Signed-off-by: Peter Zijlstra (Intel) Acked-by: Waiman Long Link: https://lkml.kernel.org/r/20200729123105.GB7047@gondor.apana.org.au

powerpc/qspinlock: Optimised atomic_try_cmpxchg_lock() that adds the lock hint

2020-07-26T14:01:29Z

This brings the behaviour of the uncontended fast path back to roughly equivalent to simple spinlocks -- a single atomic op with lock hint. Signed-off-by: Nicholas Piggin Acked-by: Waiman Long Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200724131423.1362108-6-npiggin@gmail.com

powerpc: Remove IBM405 Erratum #77

2020-05-28T13:24:36Z

This erratum is dedicated to IBM 405GP and STB03xxx which are now gone. Remove this erratum. Signed-off-by: Christophe Leroy Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/44dbc08e9034681eb28324cbabc086e97044c36c.1590079969.git.christophe.leroy@csgroup.eu