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2021-08-25powerpc/64s: Remove WORT SPR from POWER9/10Nicholas Piggin
This register is not architected and not implemented in POWER9 or 10, it just reads back zeroes for compatibility. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Link: https://lore.kernel.org/r/20210811160134.904987-11-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV Nested: Reflect guest PMU in-use to L0 when guest SPRs ↵Nicholas Piggin
are live After the L1 saves its PMU SPRs but before loading the L2's PMU SPRs, switch the pmcregs_in_use field in the L1 lppaca to the value advertised by the L2 in its VPA. On the way out of the L2, set it back after saving the L2 PMU registers (if they were in-use). This transfers the PMU liveness indication between the L1 and L2 at the points where the registers are not live. This fixes the nested HV bug for which a workaround was added to the L0 HV by commit 63279eeb7f93a ("KVM: PPC: Book3S HV: Always save guest pmu for guest capable of nesting"), which explains the problem in detail. That workaround is no longer required for guests that include this bug fix. Fixes: 360cae313702 ("KVM: PPC: Book3S HV: Nested guest entry via hypercall") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Link: https://lore.kernel.org/r/20210811160134.904987-10-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV Nested: save_hv_return_state does not require trap argumentFabiano Rosas
vcpu is already anargument so vcpu->arch.trap can be used directly. Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210811160134.904987-9-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV Nested: Stop forwarding all HFUs to L1Fabiano Rosas
If the nested hypervisor has no access to a facility because it has been disabled by the host, it should also not be able to see the Hypervisor Facility Unavailable that arises from one of its guests trying to access the facility. This patch turns a HFU that happened in L2 into a Hypervisor Emulation Assistance interrupt and forwards it to L1 for handling. The ones that happened because L1 explicitly disabled the facility for L2 are still let through, along with the corresponding Cause bits in the HFSCR. Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com> [np: move handling into kvmppc_handle_nested_exit] Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210811160134.904987-8-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV Nested: Make nested HFSCR state accessibleNicholas Piggin
When the L0 runs a nested L2, there are several permutations of HFSCR that can be relevant. The HFSCR that the L1 vcpu L1 requested, the HFSCR that the L1 vcpu may use, and the HFSCR that is actually being used to run the L2. The L1 requested HFSCR is not accessible outside the nested hcall handler, so copy that into a new kvm_nested_guest.hfscr field. The permitted HFSCR is taken from the HFSCR that the L1 runs with, which is also not accessible while the hcall is being made. Move this into a new kvm_vcpu_arch.hfscr_permitted field. These will be used by the next patch to improve facility handling for nested guests, and later by facility demand faulting patches. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210811160134.904987-7-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV Nested: Sanitise vcpu registersFabiano Rosas
As one of the arguments of the H_ENTER_NESTED hypercall, the nested hypervisor (L1) prepares a structure containing the values of various hypervisor-privileged registers with which it wants the nested guest (L2) to run. Since the nested HV runs in supervisor mode it needs the host to write to these registers. To stop a nested HV manipulating this mechanism and using a nested guest as a proxy to access a facility that has been made unavailable to it, we have a routine that sanitises the values of the HV registers before copying them into the nested guest's vcpu struct. However, when coming out of the guest the values are copied as they were back into L1 memory, which means that any sanitisation we did during guest entry will be exposed to L1 after H_ENTER_NESTED returns. This patch alters this sanitisation to have effect on the vcpu->arch registers directly before entering and after exiting the guest, leaving the structure that is copied back into L1 unchanged (except when we really want L1 to access the value, e.g the Cause bits of HFSCR). Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Link: https://lore.kernel.org/r/20210811160134.904987-6-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV Nested: Fix TM softpatch HFAC interrupt emulationNicholas Piggin
Have the TM softpatch emulation code set up the HFAC interrupt and return -1 in case an instruction was executed with HFSCR bits clear, and have the interrupt exit handler fall through to the HFAC handler. When the L0 is running a nested guest, this ensures the HFAC interrupt is correctly passed up to the L1. The "direct guest" exit handler will turn these into PROGILL program interrupts so functionality in practice will be unchanged. But it's possible an L1 would want to handle these in a different way. Also rearrange the FAC interrupt emulation code to match the HFAC format while here (mainly, adding the FSCR_INTR_CAUSE mask). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210811160134.904987-5-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV P9: Fixes for TM softpatch interrupt NIPNicholas Piggin
The softpatch interrupt sets HSRR0 to the faulting instruction +4, so it should subtract 4 for the faulting instruction address in the case it is a TM softpatch interrupt (the instruction was not executed) and it was not emulated. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210811160134.904987-4-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV: Remove TM emulation from POWER7/8 pathNicholas Piggin
TM fake-suspend emulation is only used by POWER9. Remove it from the old code path. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210811160134.904987-3-npiggin@gmail.com
2021-08-25KVM: PPC: Book3S HV: Initialise vcpu MSR with MSR_MENicholas Piggin
It is possible to create a VCPU without setting the MSR before running it, which results in a warning in kvmhv_vcpu_entry_p9() that MSR_ME is not set. This is pretty harmless because the MSR_ME bit is added to HSRR1 before HRFID to guest, and a normal qemu guest doesn't hit it. Initialise the vcpu MSR with MSR_ME set. Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210811160134.904987-2-npiggin@gmail.com
2021-08-24riscv: explicitly use symbol offsets for VDSOSaleem Abdulrasool
The current implementation of the `__rt_sigaction` reference computed an absolute offset relative to the mapped base of the VDSO. While this can be handled in the medlow model, the medany model cannot handle this as it is meant to be position independent. The current implementation relied on the BFD linker relaxing the PC-relative relocation into an absolute relocation as it was a near-zero address allowing it to be referenced relative to `zero`. We now extract the offsets and create a generated header allowing the build with LLVM and lld to succeed as we no longer depend on the linker rewriting address references near zero. This change was largely modelled after the ARM64 target which does something similar. Signed-off-by: Saleem Abdulrasool <abdulras@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-24riscv: Enable Undefined Behavior Sanitizer UBSANJisheng Zhang
Select ARCH_HAS_UBSAN_SANITIZE_ALL in order to allow the user to enable CONFIG_UBSAN_SANITIZE_ALL and instrument the entire kernel for ubsan checks. VDSO is excluded because its build doesn't include the __ubsan_handle_*() functions from lib/ubsan.c, and the VDSO has no sane way to report errors even if it has definitions of these functions. Passed lib/test_ubsan.c test. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-24riscv: Keep the riscv Kconfig selects sortedJisheng Zhang
Move three Kconfig selects: ARCH_STACKWALK, ARCH_SUPPORTS_ATOMIC_RMW and ARCH_SUPPORTS_DEBUG_PAGEALLOC to the right place. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-24riscv: dts: microchip: Add ethernet0 to the aliases nodeBin Meng
U-Boot expects this alias to be in place in order to fix up the mac address of the ethernet node. Note on the Icicle Kit board, currently only emac1 is enabled so it becomes the 'ethernet0'. Signed-off-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-24riscv: dts: microchip: Use 'local-mac-address' for emac1Bin Meng
Per the DT spec, 'local-mac-address' is used to specify MAC address that was assigned to the network device, while 'mac-address' is used to specify the MAC address that was last used by the boot program, and shall be used only if the value differs from 'local-mac-address' property value. Signed-off-by: Bin Meng <bin.meng@windriver.com> Reviewed-by: conor dooley <conor.dooley@microchip.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-24riscv: Ensure the value of FP registers in the core dump file is up to dateVincent Chen
The value of FP registers in the core dump file comes from the thread.fstate. However, kernel saves the FP registers to the thread.fstate only before scheduling out the process. If no process switch happens during the exception handling process, kernel will not have a chance to save the latest value of FP registers to thread.fstate. It will cause the value of FP registers in the core dump file may be incorrect. To solve this problem, this patch force lets kernel save the FP register into the thread.fstate if the target task_struct equals the current. Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Jisheng Zhang <jszhang@kernel.org> Fixes: b8c8a9590e4f ("RISC-V: Add FP register ptrace support for gdb.") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-08-25powerpc: Use lwarx/ldarx directly instead of PPC_LWARX/LDARX macrosChristophe Leroy
Force the eh flag at 0 on PPC32. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1fc81f07cabebb875b963e295408cc3dd38c8d85.1614674882.git.christophe.leroy@csgroup.eu
2021-08-25powerpc/ptrace: Make user_mode() common to PPC32 and PPC64Christophe Leroy
Today we have: #ifdef __powerpc64__ #define user_mode(regs) ((((regs)->msr) >> MSR_PR_LG) & 0x1) #else #define user_mode(regs) (((regs)->msr & MSR_PR) != 0) #endif With ppc64_defconfig, we get: if (!user_mode(regs)) 14b4: e9 3e 01 08 ld r9,264(r30) 14b8: 71 29 40 00 andi. r9,r9,16384 14bc: 41 82 07 a4 beq 1c60 <.emulate_instruction+0x7d0> If taking the ppc32 definition of user_mode(), the exact same code is generated for ppc64_defconfig. So, only keep one version of user_mode(), preferably the one not using MSR_PR_LG which should be kept internal to reg.h. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/000a28c51808bbd802b505af42d2cb316c2be7d3.1629216000.git.christophe.leroy@csgroup.eu
2021-08-25powerpc/syscalls: Simplify do_mmap2()Christophe Leroy
When shift is nul, operations remain valid so no test needed. And 'ret' is unnecessary. And use IS_ALIGNED() to check alignment, that's more clear. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/373ec500f386374bc5735007df3d3869eac47be1.1624618701.git.christophe.leroy@csgroup.eu
2021-08-25powerpc/ptdump: Convert powerpc to GENERIC_PTDUMPChristophe Leroy
This patch converts powerpc to the generic PTDUMP implementation. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/03166d569526be70214fe9370a7bad219d2f41c8.1625762907.git.christophe.leroy@csgroup.eu
2021-08-25powerpc/ptdump: Reduce level numbers by 1 in note_page() and add p4d levelChristophe Leroy
Do the same as commit f8f0d0b6fa20 ("mm: ptdump: reduce level numbers by 1 in note_page()") and add missing p4d level. This will align powerpc to the users of generic ptdump. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/d76495c574132b197b445a1f133755cca4b912a4.1625762906.git.christophe.leroy@csgroup.eu
2021-08-25powerpc/ptdump: Remove unused 'page_size' parameterChristophe Leroy
note_page_update_state() doesn't use page_size. Remove it. Could also be removed to note_page() but as a following patch will remove all current users of note_page(), just leave it as is for now. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e2f80d052001155251bfe009c360d0c5d9242c6b.1625762906.git.christophe.leroy@csgroup.eu
2021-08-25powerpc/ptdump: Use DEFINE_SHOW_ATTRIBUTE()Christophe Leroy
Use DEFINE_SHOW_ATTRIBUTE() instead of open coding open() and fops. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/b864a92693ca8413ef0b19f0c12065c212899b6e.1625762905.git.christophe.leroy@csgroup.eu
2021-08-25powerpc: Avoid link stack corruption in misc asm functionsChristophe Leroy
bl;mflr is used at several places to get code position. Use bcl 20,31,+4 instead of bl in order to preserve link stack. See commit c974809a26a1 ("powerpc/vdso: Avoid link stack corruption in __get_datapage()") for details. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c6eabb4fb6c156f75d56dcbcc6f243e5ac0fba42.1629791763.git.christophe.leroy@csgroup.eu
2021-08-25powerpc/booke: Avoid link stack corruption in several placesChristophe Leroy
Use bcl 20,31,+4 instead of bl in order to preserve link stack. See commit c974809a26a1 ("powerpc/vdso: Avoid link stack corruption in __get_datapage()") for details. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e9fbc285eceb720e6c0e032ef47fe8b05f669b48.1629791751.git.christophe.leroy@csgroup.eu
2021-08-25powerpc/32: indirect function call use bctrl rather than blrl in ↵Christophe Leroy
ret_from_kernel_thread Copied from commit 89bbe4c798bc ("powerpc/64: indirect function call use bctrl rather than blrl in ret_from_kernel_thread") blrl is not recommended to use as an indirect function call, as it may corrupt the link stack predictor. This is not a performance critical path but this should be fixed for consistency. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/91b1d242525307ceceec7ef6e832bfbacdd4501b.1629436472.git.christophe.leroy@csgroup.eu
2021-08-24arm64: kdump: Remove custom linux,usable-memory-range handlingGeert Uytterhoeven
Remove the architecture-specific code for handling the "linux,usable-memory-range" property under the "/chosen" node in DT, as the platform-agnostic FDT core code already takes care of this. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/7356c531c49a24b4a55577bf8e46d93f4d8ae460.1628670468.git.geert+renesas@glider.be
2021-08-24arm64: kdump: Remove custom linux,elfcorehdr handlingGeert Uytterhoeven
Remove the architecture-specific code for handling the "linux,elfcorehdr" property under the "/chosen" node in DT, as the platform-agnostic handling in the FDT core code already takes care of this. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/3b8f801f9b92066855e87f3079fafc153ab20f69.1628670468.git.geert+renesas@glider.be
2021-08-24riscv: Remove non-standard linux,elfcorehdr handlingGeert Uytterhoeven
RISC-V uses platform-specific code to locate the elf core header in memory. However, this does not conform to the standard "linux,elfcorehdr" DT bindings, as it relies on a reserved memory node with the "linux,elfcorehdr" compatible value, instead of on a "linux,elfcorehdr" property under the "/chosen" node. The non-compliant code can just be removed, as the standard behavior is already implemented by platform-agnostic handling in the FDT core code. Fixes: 5640975003d0234d ("RISC-V: Add crash kernel support") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/41c75d6ee3114ae6304f8afe0051895af91200ee.1628670468.git.geert+renesas@glider.be
2021-08-24ARC: mm: move MMU specific bits out of entry code ...Vineet Gupta
... to avoid polluting shared entry code (across three ISA variants) with ISA/MMU specific code. Cc: Jose Abreu <joabreu@synopsys.com> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: mm: move MMU specific bits out of ASID allocatorVineet Gupta
And while at it, rewrite commentary on ASID allocator Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: mm: non-functional code movement/cleanupVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: mm: pmd_populate* to use the canonical set_pmd (and drop pmd_set)Vineet Gupta
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: ioremap: use more commonly used PAGE_KERNEL based uncached flagVineet Gupta
and remove the one off uncached definition for ARC Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: mm: Enable STRICT_MM_TYPECHECKSVineet Gupta
In the past I've refrained from doing this (at least 2 times) due to the slight code bloat due to ABI implications of pte_t etc becoming struct Per ARC ABI, functions return struct via memory and not through register r0, even if the struct would fit in register(s) - caller allocates space on stack and passes the address as first arg (r0), shifting rest of args by one - callee creates return struct in memory (referenced via r0) This time around the code actually shrunk slightly (due to subtle inlining heuristic effects), but still slightly inefficient due to return values passed through memory. That however seems like a small cost compared to maintenance burden given the impending new mmu support for page walk etc Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: mm: Fixes to allow STRICT_MM_TYPECHECKSVineet Gupta
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: mm: move mmu/cache externs out to setup.hVineet Gupta
Don't pollute mmu.h and cache.h with ARC internal bootlog/setup related functions. Move them aside to setup.h Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: mm: remove tlb paranoid codeVineet Gupta
This was used back in arc700 days when ASID allocator was fragile. Not needed in last 5 years Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: mm: use SCRATCH_DATA0 register for caching pgdir in ARCv2 onlyVineet Gupta
MMU SCRATCH_DATA0 register is intended to cache task pgd. However in ARC700 SMP port, it has to be repurposed for re-entrant interrupt handling, while UP port doesn't. We currently handle these use-cases using a fabricated #define which has usual issues of dependency nesting and obvious ugliness. So clean this up: for ARC700 don't use to cache pgd (even in UP) and do the opposite for ARCv2. And while here, switch to canonical pgd_offset(). Acked-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: retire MMUv1 and MMUv2 supportVineet Gupta
There's no known/active customer using them with latest kernels anyways. Removal helps cleanup code and remove the hack for MMU_VER to MMU_V[3-4] conversion Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: retire ARC750 supportVineet Gupta
There's no known/active customer using them with latest kernels anyways. Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: atomic_cmpxchg/atomic_xchg: implement relaxed variantsVineet Gupta
And move them out of cmpxchg.h to canonical atomic.h Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: cmpxchg/xchg: implement relaxed variants (LLSC config only)Vineet Gupta
It only makes sense to do this for the LLSC config Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: cmpxchg/xchg: rewrite as macros to make type safeVineet Gupta
Existing code forces/assume args to type "long" which won't work in LP64 regime, so prepare code for that Interestingly this should be a non functional change but I do see some codegen changes | bloat-o-meter vmlinux-cmpxchg-A vmlinux-cmpxchg-B | add/remove: 0/0 grow/shrink: 17/12 up/down: 218/-150 (68) | | Function old new delta | rwsem_optimistic_spin 518 550 +32 | rwsem_down_write_slowpath 1244 1274 +30 | __do_sys_perf_event_open 2576 2600 +24 | down_read 192 200 +8 | __down_read 192 200 +8 ... | task_work_run 168 148 -20 | dma_fence_chain_walk.part 760 736 -24 | __genradix_ptr_alloc 674 646 -28 Total: Before=6187409, After=6187477, chg +0.00% Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: xchg: !LLSC: remove UP micro-optimization/hackVineet Gupta
It gets in the way of cleaning things up and is a maintenance pain-in-neck ! Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: bitops: fls/ffs to take int (vs long) per asm-generic definesVineet Gupta
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: switch to generic bitopsVineet Gupta
- !LLSC now only needs a single spinlock for atomics and bitops - Some codegen changes (slight bloat) with generic bitops 1. code increase due to LD-check-atomic paradigm vs. unconditonal atomic (but dirty'ing the cache line even if set already). So despite increase, generic is right thing to do. 2. code decrease (but use of costlier instructions such as DIV vs. shifts based math) due to signed arithmetic. This needs to be revisited seperately. arc: static inline int test_bit(unsigned int nr, const volatile unsigned long *addr) ^^^^^^^^^^^^ generic: static inline int test_bit(int nr, const volatile unsigned long *addr) ^^^ Link: https://lore.kernel.org/r/20180830135749.GA13005@arm.com Signed-off-by: Will Deacon <will@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> [vgupta: wrote patch based on Will's poc, analysed codegen diffs] Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: atomics: implement relaxed variantsVineet Gupta
The current ARC fetch/return atomics provide fully ordered semantics only with 2 full barriers around the operation. Instead implement them as relaxed variants without any barriers and rely on generic code to generate the fully-ordered, acquire and release varaints by adding the appropriate full barriers. This helps elide some extra barriers in case of acquire/release/relaxed calls. bloat-o-meter for hsdk defconfig shows codegen improvements, although numbers below inflated due to unrelated inlining heuristic changes | bloat-o-meter vmlinux-643babe34fd7-non-relaxed vmlinux-45aa05cb44d7-relaxed | add/remove: 2/5 grow/shrink: 42/1222 up/down: 4158/-14312 (-10154) | Function old new delta | .. | sys_renameat 462 476 +14 | ip_mc_inc_group 424 436 +12 | do_read_cache_page 1882 1894 +12 | .. | refcount_dec_and_mutex_lock 254 250 -4 | refcount_dec_and_lock_irqsave 258 254 -4 | refcount_dec_and_lock 254 250 -4 | .. | tcp_v6_route_req 246 238 -8 | tcp_v4_destroy_sock 286 278 -8 | tcp_twsk_unique 352 344 -8 Link: https://lore.kernel.org/r/20180830144344.GW24142@hirez.programming.kicks-ass.net Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: atomic64: LLSC: elide unused atomic_{and,or,xor,andnot}_returnVineet Gupta
This is a non-functional change since those wrappers are not used in kernel sources at all. Link: http://lists.infradead.org/pipermail/linux-snps-arc/2018-August/004246.html Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@kernel.org>
2021-08-24ARC: atomic: !LLSC: use int data type consistentlyVineet Gupta
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Vineet Gupta <vgupta@kernel.org>