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* riscv: Move early dtb mapping into the fixmap regionAlexandre Ghiti2023-04-132-2/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | riscv establishes 2 virtual mappings: - early_pg_dir maps the kernel which allows to discover the system memory - swapper_pg_dir installs the final mapping (linear mapping included) We used to map the dtb in early_pg_dir using DTB_EARLY_BASE_VA, and this mapping was not carried over in swapper_pg_dir. It happens that early_init_fdt_scan_reserved_mem() must be called before swapper_pg_dir is setup otherwise we could allocate reserved memory defined in the dtb. And this function initializes reserved_mem variable with addresses that lie in the early_pg_dir dtb mapping: when those addresses are reused with swapper_pg_dir, this mapping does not exist and then we trap. The previous "fix" was incorrect as early_init_fdt_scan_reserved_mem() must be called before swapper_pg_dir is set up otherwise we could allocate in reserved memory defined in the dtb. So move the dtb mapping in the fixmap region which is established in early_pg_dir and handed over to swapper_pg_dir. Fixes: 922b0375fc93 ("riscv: Fix memblock reservation for device tree blob") Fixes: 8f3a2b4a96dc ("RISC-V: Move DT mapping outof fixmap") Fixes: 50e63dd8ed92 ("riscv: fix reserved memory setup") Reported-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/all/f8e67f82-103d-156c-deb0-d6d6e2756f5e@microchip.com/ Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230329081932.79831-2-alexghiti@rivosinc.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* Merge patch series "RISC-V: Fixes for riscv_has_extension[un]likely()'s ↵Palmer Dabbelt2023-03-291-20/+30
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | alternative dependency" Conor Dooley <conor.dooley@microchip.com> says: Here's my attempt at fixing both the use of an FPU on XIP kernels and the issue that Jason ran into where CONFIG_FPU, which needs the alternatives frame work for has_fpu() checks, could be enabled without the alternatives actually being present. For the former, a "slow" fallback that does not use alternatives is added to riscv_has_extension_[un]likely() that can be used with XIP. Obviously, we want to make use of Jisheng's alternatives based approach where possible, so any users of riscv_has_extension_[un]likely() will want to make sure that they select RISCV_ALTERNATIVE. If they don't however, they'll hit the fallback path which (should, sparing a silly mistake from me!) behave in the same way, thus succeeding silently. Sounds like a To prevent "depends on !XIP_KERNEL; select RISCV_ALTERNATIVE" spreading like the plague through the various places that want to check for the presence of extensions, and sidestep the potential silent "success" mentioned above, all users RISCV_ALTERNATIVE are converted from selects to dependencies, with the option being selected for all !XIP_KERNEL builds. I know that the VDSO was a key place that Jisheng wanted to use the new helper rather than static branches, and I think the fallback path should not cause issues there. See the thread at [1] for the prior discussion. 1 - https://lore.kernel.org/linux-riscv/20230128172856.3814-1-jszhang@kernel.org/T/#m21390d570997145d31dd8bb95002fd61f99c6573 [Palmer: merging in the fixes as a branch as there's some features that depend on it.] * b4-shazam-merge: RISC-V: always select RISCV_ALTERNATIVE for non-xip kernels RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely() Link: https://lore.kernel.org/r/20230324100538.3514663-1-conor.dooley@microchip.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely()Conor Dooley2023-03-291-20/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The has_fpu() check, which in turn calls riscv_has_extension_likely(), relies on alternatives to figure out whether the system has an FPU. As a result, it will malfunction on XIP kernels, as they do not support the alternatives mechanism. When alternatives support is not present, fall back to using __riscv_isa_extension_available() in riscv_has_extension_[un]likely() instead stead, which handily takes the same argument, so that kernels that do not support alternatives can accurately report the presence of FPU support. Fixes: 702e64550b12 ("riscv: fpu: switch has_fpu() to riscv_has_extension_likely()") Link: https://lore.kernel.org/all/ad445951-3d13-4644-94d9-e0989cda39c3@spud/ Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20230324100538.3514663-2-conor.dooley@microchip.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* | riscv: mm: Fix incorrect ASID argument when flushing TLBDylan Jhong2023-03-211-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | Currently, we pass the CONTEXTID instead of the ASID to the TLB flush function. We should only take the ASID field to prevent from touching the reserved bit field. Fixes: 3f1e782998cd ("riscv: add ASID-based tlbflushing methods") Signed-off-by: Dylan Jhong <dylan@andestech.com> Reviewed-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com> Link: https://lore.kernel.org/r/20230313034906.2401730-1-dylan@andestech.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* | Merge patch series "riscv: asid: switch to alternative way to fix stale TLB ↵Palmer Dabbelt2023-03-092-20/+0
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | entries" Sergey Matyukevich <geomatsi@gmail.com> says: Some time ago two different patches have been posted to fix stale TLB entries that caused applications crashes. The patch [0] suggested 'aggregating' mm_cpumask, i.e. current cpu is not cleared for the switched-out task in switch_mm function. For additional explanations see the commit message by Guo Ren. The same approach is used by arc architecture, so another good comment is for switch_mm in arch/arc/include/asm/mmu_context.h. The patch [1] attempted to reduce the number of TLB flushes by deferring (and possibly avoiding) them for CPUs not running the task. Patch [1] has been merged. However we already have two bug reports from different vendors. So apparently something is missing in the approach suggested in [1]. In both cases the patch [0] fixed the issue. This patch series reverts [1] and replaces it by [0]. [0] https://lore.kernel.org/linux-riscv/20221111075902.798571-1-guoren@kernel.org/ [1] https://lore.kernel.org/linux-riscv/20220829205219.283543-1-geomatsi@gmail.com/ * b4-shazam-merge: riscv: asid: Fixup stale TLB entry cause application crash Revert "riscv: mm: notify remote harts about mmu cache updates" Link: https://lore.kernel.org/r/20230226150137.1919750-1-geomatsi@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | Revert "riscv: mm: notify remote harts about mmu cache updates"Sergey Matyukevich2023-03-092-20/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts the remaining bits of commit 4bd1d80efb5a ("riscv: mm: notify remote harts harts about mmu cache updates"). According to bug reports, suggested approach to fix stale TLB entries is not sufficient. It needs to be replaced by a more robust solution. Fixes: 4bd1d80efb5a ("riscv: mm: notify remote harts about mmu cache updates") Reported-by: Zong Li <zong.li@sifive.com> Reported-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com> Cc: stable@vger.kernel.org Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230226150137.1919750-2-geomatsi@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* | | RISC-V: Don't check text_mutex during stop_machineConor Dooley2023-03-092-1/+3
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We're currently using stop_machine() to update ftrace & kprobes, which means that the thread that takes text_mutex during may not be the same as the thread that eventually patches the code. This isn't actually a race because the lock is still held (preventing any other concurrent accesses) and there is only one thread running during stop_machine(), but it does trigger a lockdep failure. This patch just elides the lockdep check during stop_machine. Fixes: c15ac4fd60d5 ("riscv/ftrace: Add dynamic function tracer support") Suggested-by: Steven Rostedt <rostedt@goodmis.org> Reported-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230303143754.4005217-1-conor.dooley@microchip.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* | Merge tag 'riscv-for-linus-6.3-mw2' of ↵Linus Torvalds2023-03-031-0/+8
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull more RISC-V updates from Palmer Dabbelt: - Some cleanups and fixes for the Zbb-optimized string routines - Support for custom (vendor or implementation defined) perf events - COMMAND_LINE_SIZE has been increased to 1024 * tag 'riscv-for-linus-6.3-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: Bump COMMAND_LINE_SIZE value to 1024 drivers/perf: RISC-V: Allow programming custom firmware events riscv, lib: Fix Zbb strncmp RISC-V: improve string-function assembly
| * | riscv: Bump COMMAND_LINE_SIZE value to 1024Alexandre Ghiti2023-03-011-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Increase COMMAND_LINE_SIZE as the current default value is too low for syzbot kernel command line. There has been considerable discussion on this patch that has led to a larger patch set removing COMMAND_LINE_SIZE from the uapi headers on all ports. That's not quite done yet, but it's gotten far enough we're confident this is not a uABI change so this is safe. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> Link: https://lore.kernel.org/r/20210316193420.904-1-alex@ghiti.fr [Palmer: it's not uabi] Link: https://lore.kernel.org/linux-riscv/874b8076-b0d1-4aaa-bcd8-05d523060152@app.fastmail.com/#t Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
* | | Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2023-02-254-8/+130
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull kvm updates from Paolo Bonzini: "ARM: - Provide a virtual cache topology to the guest to avoid inconsistencies with migration on heterogenous systems. Non secure software has no practical need to traverse the caches by set/way in the first place - Add support for taking stage-2 access faults in parallel. This was an accidental omission in the original parallel faults implementation, but should provide a marginal improvement to machines w/o FEAT_HAFDBS (such as hardware from the fruit company) - A preamble to adding support for nested virtualization to KVM, including vEL2 register state, rudimentary nested exception handling and masking unsupported features for nested guests - Fixes to the PSCI relay that avoid an unexpected host SVE trap when resuming a CPU when running pKVM - VGIC maintenance interrupt support for the AIC - Improvements to the arch timer emulation, primarily aimed at reducing the trap overhead of running nested - Add CONFIG_USERFAULTFD to the KVM selftests config fragment in the interest of CI systems - Avoid VM-wide stop-the-world operations when a vCPU accesses its own redistributor - Serialize when toggling CPACR_EL1.SMEN to avoid unexpected exceptions in the host - Aesthetic and comment/kerneldoc fixes - Drop the vestiges of the old Columbia mailing list and add [Oliver] as co-maintainer RISC-V: - Fix wrong usage of PGDIR_SIZE instead of PUD_SIZE - Correctly place the guest in S-mode after redirecting a trap to the guest - Redirect illegal instruction traps to guest - SBI PMU support for guest s390: - Sort out confusion between virtual and physical addresses, which currently are the same on s390 - A new ioctl that performs cmpxchg on guest memory - A few fixes x86: - Change tdp_mmu to a read-only parameter - Separate TDP and shadow MMU page fault paths - Enable Hyper-V invariant TSC control - Fix a variety of APICv and AVIC bugs, some of them real-world, some of them affecting architecurally legal but unlikely to happen in practice - Mark APIC timer as expired if its in one-shot mode and the count underflows while the vCPU task was being migrated - Advertise support for Intel's new fast REP string features - Fix a double-shootdown issue in the emergency reboot code - Ensure GIF=1 and disable SVM during an emergency reboot, i.e. give SVM similar treatment to VMX - Update Xen's TSC info CPUID sub-leaves as appropriate - Add support for Hyper-V's extended hypercalls, where "support" at this point is just forwarding the hypercalls to userspace - Clean up the kvm->lock vs. kvm->srcu sequences when updating the PMU and MSR filters - One-off fixes and cleanups - Fix and cleanup the range-based TLB flushing code, used when KVM is running on Hyper-V - Add support for filtering PMU events using a mask. If userspace wants to restrict heavily what events the guest can use, it can now do so without needing an absurd number of filter entries - Clean up KVM's handling of "PMU MSRs to save", especially when vPMU support is disabled - Add PEBS support for Intel Sapphire Rapids - Fix a mostly benign overflow bug in SEV's send|receive_update_data() - Move several SVM-specific flags into vcpu_svm x86 Intel: - Handle NMI VM-Exits before leaving the noinstr region - A few trivial cleanups in the VM-Enter flows - Stop enabling VMFUNC for L1 purely to document that KVM doesn't support EPTP switching (or any other VM function) for L1 - Fix a crash when using eVMCS's enlighted MSR bitmaps Generic: - Clean up the hardware enable and initialization flow, which was scattered around multiple arch-specific hooks. Instead, just let the arch code call into generic code. Both x86 and ARM should benefit from not having to fight common KVM code's notion of how to do initialization - Account allocations in generic kvm_arch_alloc_vm() - Fix a memory leak if coalesced MMIO unregistration fails selftests: - On x86, cache the CPU vendor (AMD vs. Intel) and use the info to emit the correct hypercall instruction instead of relying on KVM to patch in VMMCALL - Use TAP interface for kvm_binary_stats_test and tsc_msrs_test" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (325 commits) KVM: SVM: hyper-v: placate modpost section mismatch error KVM: x86/mmu: Make tdp_mmu_allowed static KVM: arm64: nv: Use reg_to_encoding() to get sysreg ID KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes KVM: arm64: nv: Filter out unsupported features from ID regs KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2 KVM: arm64: nv: Allow a sysreg to be hidden from userspace only KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor KVM: arm64: nv: Add accessors for SPSR_EL1, ELR_EL1 and VBAR_EL1 from virtual EL2 KVM: arm64: nv: Handle SMCs taken from virtual EL2 KVM: arm64: nv: Handle trapped ERET from virtual EL2 KVM: arm64: nv: Inject HVC exceptions to the virtual EL2 KVM: arm64: nv: Support virtual EL2 exceptions KVM: arm64: nv: Handle HCR_EL2.NV system register traps KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state KVM: arm64: nv: Add EL2 system registers to vcpu context KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set KVM: arm64: nv: Introduce nested virtualization VCPU feature KVM: arm64: Use the S2 MMU context to iterate over S2 table ...
| * | Merge tag 'kvm-riscv-6.3-1' of https://github.com/kvm-riscv/linux into HEADPaolo Bonzini2023-02-157-24/+140
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KVM/riscv changes for 6.3 - Fix wrong usage of PGDIR_SIZE to check page sizes - Fix privilege mode setting in kvm_riscv_vcpu_trap_redirect() - Redirect illegal instruction traps to guest - SBI PMU support for guest
| | * | RISC-V: KVM: Support firmware eventsAtish Patra2023-02-071-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | SBI PMU extension defines a set of firmware events which can provide useful information to guests about the number of SBI calls. As hypervisor implements the SBI PMU extension, these firmware events correspond to ecall invocations between VS->HS mode. All other firmware events will always report zero if monitored as KVM doesn't implement them. This patch adds all the infrastructure required to support firmware events. Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
| | * | RISC-V: KVM: Implement trap & emulate for hpmcountersAtish Patra2023-02-071-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As the KVM guests only see the virtual PMU counters, all hpmcounter access should trap and KVM emulates the read access on behalf of guests. Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
| | * | RISC-V: KVM: Add skeleton support for perfAtish Patra2023-02-072-0/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch only adds barebone structure of perf implementation. Most of the function returns zero at this point and will be implemented fully in the future. Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
| | * | RISC-V: KVM: Modify SBI extension handler to return SBI error codeAtish Patra2023-02-071-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the SBI extension handle is expected to return Linux error code. The top SBI layer converts the Linux error code to SBI specific error code that can be returned to guest invoking the SBI calls. This model works as long as SBI error codes have 1-to-1 mappings between them. However, that may not be true always. This patch attempts to disassociate both these error codes by allowing the SBI extension implementation to return SBI specific error codes as well. The extension will continue to return the Linux error specific code which will indicate any problem *with* the extension emulation while the SBI specific error will indicate the problem *of* the emulation. Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Suggested-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
| | * | RISC-V: KVM: Define a probe function for SBI extension data structuresAtish Patra2023-02-071-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the probe function just checks if an SBI extension is registered or not. However, the extension may not want to advertise itself depending on some other condition. An additional extension specific probe function will allow extensions to decide if they want to be advertised to the caller or not. Any extension that does not require additional dependency checks can avoid implementing this function. Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
| | * | RISC-V: Improve SBI PMU extension related definitionsAtish Patra2023-02-071-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes/improve few minor things in SBI PMU extension definition. 1. Align all the firmware event names. 2. Add macros for bit positions in cache event ID & ops. The changes were small enough to combine them together instead of creating 1 liner patches. Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
| * | | Merge branch 'kvm-v6.2-rc4-fixes' into HEADPaolo Bonzini2023-01-241-1/+1
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ARM: * Fix the PMCR_EL0 reset value after the PMU rework * Correctly handle S2 fault triggered by a S1 page table walk by not always classifying it as a write, as this breaks on R/O memslots * Document why we cannot exit with KVM_EXIT_MMIO when taking a write fault from a S1 PTW on a R/O memslot * Put the Apple M2 on the naughty list for not being able to correctly implement the vgic SEIS feature, just like the M1 before it * Reviewer updates: Alex is stepping down, replaced by Zenghui x86: * Fix various rare locking issues in Xen emulation and teach lockdep to detect them * Documentation improvements * Do not return host topology information from KVM_GET_SUPPORTED_CPUID
| * | | | KVM: RISC-V: Tag init functions and data with __init, __ro_after_initSean Christopherson2022-12-291-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that KVM setup is handled directly in riscv_kvm_init(), tag functions and data that are used/set only during init with __init/__ro_after_init. Signed-off-by: Sean Christopherson <seanjc@google.com> Acked-by: Anup Patel <anup@brainfault.org> Message-Id: <20221130230934.1014142-26-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| * | | | KVM: Drop arch hardware (un)setup hooksSean Christopherson2022-12-291-1/+0
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Drop kvm_arch_hardware_setup() and kvm_arch_hardware_unsetup() now that all implementations are nops. No functional change intended. Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Eric Farman <farman@linux.ibm.com> # s390 Acked-by: Anup Patel <anup@brainfault.org> Message-Id: <20221130230934.1014142-10-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
* | | | Merge tag 'riscv-for-linus-6.3-mw1' of ↵Linus Torvalds2023-02-2517-320/+604
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: "There's a bunch of fixes/cleanups throughout the tree as usual, but we also have a handful of new features: - Various improvements to the extension detection and alternative patching infrastructure - Zbb-optimized string routines - Support for cpu-capacity in the RISC-V DT bindings - Zicbom no longer depends on toolchain support - Some performance and code size improvements to ftrace - Support for ARCH_WANT_LD_ORPHAN_WARN - Oops now contain the faulting instruction" * tag 'riscv-for-linus-6.3-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (67 commits) RISC-V: add a spin_shadow_stack declaration riscv: mm: hugetlb: Enable ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP riscv: Add header include guards to insn.h riscv: alternative: proceed one more instruction for auipc/jalr pair riscv: Avoid enabling interrupts in die() riscv, mm: Perform BPF exhandler fixup on page fault RISC-V: take text_mutex during alternative patching riscv: hwcap: Don't alphabetize ISA extension IDs RISC-V: fix ordering of Zbb extension riscv: jump_label: Fixup unaligned arch_static_branch function RISC-V: Only provide the single-letter extensions in HWCAP riscv: mm: fix regression due to update_mmu_cache change scripts/decodecode: Add support for RISC-V riscv: Add instruction dump to RISC-V splats riscv: select ARCH_WANT_LD_ORPHAN_WARN for !XIP_KERNEL riscv: vmlinux.lds.S: explicitly catch .init.bss sections from EFI stub riscv: vmlinux.lds.S: explicitly catch .riscv.attributes sections riscv: vmlinux.lds.S: explicitly catch .rela.dyn symbols riscv: lds: define RUNTIME_DISCARD_EXIT RISC-V: move some stray __RISCV_INSN_FUNCS definitions from kprobes ...
| * | | | RISC-V: add a spin_shadow_stack declarationConor Dooley2023-02-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The patchwork automation reported a sparse complaint that spin_shadow_stack was not declared and should be static: ../arch/riscv/kernel/traps.c:335:15: warning: symbol 'spin_shadow_stack' was not declared. Should it be static? However, this is used in entry.S and therefore shouldn't be static. The same applies to the shadow_stack that this pseudo spinlock is trying to protect, so do like its charge and add a declaration to thread_info.h Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Fixes: 7e1864332fbc ("riscv: fix race when vmap stack overflow") Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230210185945.915806-1-conor@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | riscv: Add header include guards to insn.hLiao Chang2023-02-211-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add header include guards to insn.h to prevent repeating declaration of any identifiers in insn.h. Fixes: edde5584c7ab ("riscv: Add SW single-step support for KDB") Signed-off-by: Liao Chang <liaochang1@huawei.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Fixes: c9c1af3f186a ("RISC-V: rename parse_asm.h to insn.h") Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230129094242.282620-1-liaochang1@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | riscv: hwcap: Don't alphabetize ISA extension IDsAndrew Jones2023-02-211-22/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While the comment above the ISA extension ID definitions says "Entries are sorted alphabetically.", this stopped being good advice with commit d8a3d8a75206 ("riscv: hwcap: make ISA extension ids can be used in asm"), as we now use macros instead of enums. Reshuffling defines is error-prone, so, since they don't need to be in any particular order, change the advice to just adding new extensions at the bottom. Also, take the opportunity to change spaces to tabs, merge three comments into one, and move the base and max defines into more logical locations wrt the ID definitions. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230209123636.123537-1-ajones@ventanamicro.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | riscv: jump_label: Fixup unaligned arch_static_branch functionAndy Chiu2023-02-211-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Runtime code patching must be done at a naturally aligned address, or we may execute on a partial instruction. We have encountered problems traced back to static jump functions during the test. We switched the tracer randomly for every 1~5 seconds on a dual-core QEMU setup and found the kernel sucking at a static branch where it jumps to itself. The reason is that the static branch was 2-byte but not 4-byte aligned. Then, the kernel would patch the instruction, either J or NOP, with two half-word stores if the machine does not have efficient unaligned accesses. Thus, moments exist where half of the NOP mixes with the other half of the J when transitioning the branch. In our particular case, on a little-endian machine, the upper half of the NOP was mixed with the lower part of the J when enabling the branch, resulting in a jump that jumped to itself. Conversely, it would result in a HINT instruction when disabling the branch, but it might not be observable. ARM64 does not have this problem since all instructions must be 4-byte aligned. Fixes: ebc00dde8a97 ("riscv: Add jump-label implementation") Link: https://lore.kernel.org/linux-riscv/20220913094252.3555240-6-andy.chiu@sifive.com/ Reviewed-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Signed-off-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230206090440.1255001-1-guoren@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | RISC-V: Only provide the single-letter extensions in HWCAPPalmer Dabbelt2023-02-212-12/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent refactoring led to us leaking some HWCAP bits to userspace that didn't make much sense. With any luck we'll have a better scheme soon, but for now just mask off those bits to avoid polluting userspace. Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230202233832.11036-1-palmer@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | riscv: mm: fix regression due to update_mmu_cache changeSergey Matyukevich2023-02-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a partial revert of the commit 4bd1d80efb5a ("riscv: mm: notify remote harts about mmu cache updates"). Original commit included two loosely related changes serving the same purpose of fixing stale TLB entries causing user-space application crash: - introduce deferred per-ASID TLB flush for CPUs not running the task - switch to per-ASID TLB flush on all CPUs running the task in update_mmu_cache According to report and discussion in [1], the second part caused a regression on Renesas RZ/Five SoC. For now restore the old behavior of the update_mmu_cache. [1] https://lore.kernel.org/linux-riscv/20220829205219.283543-1-geomatsi@gmail.com/ Fixes: 4bd1d80efb5a ("riscv: mm: notify remote harts about mmu cache updates") Reported-by: "Lad, Prabhakar" <prabhakar.csengg@gmail.com> Signed-off-by: Sergey Matyukevich <sergey.matyukevich@syntacore.com> Link: trailer, so that it can be parsed with git's trailer functionality? Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230129211818.686557-1-geomatsi@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | RISC-V: move some stray __RISCV_INSN_FUNCS definitions from kprobesHeiko Stuebner2023-02-151-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __RISCV_INSN_FUNCS originally declared riscv_insn_is_* functions inside the kprobes implementation. This got moved into a central header in commit ec5f90877516 ("RISC-V: Move riscv_insn_is_* macros into a common header"). Though it looks like I overlooked two of them, so fix that. FENCE itself is an instruction defined directly by its own opcode, while the created riscv_isn_is_system function covers all instructions defined under the SYSTEM opcode. Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230113211955.3534431-1-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | Merge patch series "riscv: Optimize function trace"Palmer Dabbelt2023-02-151-12/+38
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | guoren@kernel.org <guoren@kernel.org> says: From: Guo Ren <guoren@linux.alibaba.com> The previous ftrace detour implementation fc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT") contain three problems. - The most horrible bug is preemption panic which found by Andy [1]. Let's disable preemption for ftrace first, and Andy could continue the ftrace preemption work. - The "-fpatchable-function-entry= CFLAG" wasted code size !RISCV_ISA_C. - The ftrace detour implementation wasted code size. - When livepatching, the trampoline (ftrace_regs_caller) would not return to <func_prolog+12> but would rather jump to the new function. So, "REG_L ra, -SZREG(sp)" would not run and the original return address would not be restored. The kernel is likely to hang or crash as a result. (Found by Evgenii Shatokhin [4]) [Palmer: The first three patches in this series are pretty concrete fixes, so I'm pulling them ahead of the rest of the series.] * b4-shazam-merge: riscv: ftrace: Reduce the detour code size to half riscv: ftrace: Remove wasted nops for !RISCV_ISA_C riscv: ftrace: Fixup panic by disabling preemption Link: https://lore.kernel.org/r/20230112090603.1295340-1-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | riscv: ftrace: Reduce the detour code size to halfGuo Ren2023-02-151-12/+38
| | |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use a temporary register to reduce the size of detour code from 16 bytes to 8 bytes. The previous implementation is from 'commit afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT")'. Before the patch: <func_prolog>: 0: REG_S ra, -SZREG(sp) 4: auipc ra, ? 8: jalr ?(ra) 12: REG_L ra, -SZREG(sp) (func_boddy) After the patch: <func_prolog>: 0: auipc t0, ? 4: jalr t0, ?(t0) (func_boddy) This patch not just reduces the size of detour code, but also fixes an important issue: An Ftrace callback registered with FTRACE_OPS_FL_IPMODIFY flag can actually change the instruction pointer, e.g. to "replace" the given kernel function with a new one, which is needed for livepatching, etc. In this case, the trampoline (ftrace_regs_caller) would not return to <func_prolog+12> but would rather jump to the new function. So, "REG_L ra, -SZREG(sp)" would not run and the original return address would not be restored. The kernel is likely to hang or crash as a result. This can be easily demonstrated if one tries to "replace", say, cmdline_proc_show() with a new function with the same signature using instruction_pointer_set(&fregs->regs, new_func_addr) in the Ftrace callback. Link: https://lore.kernel.org/linux-riscv/20221122075440.1165172-1-suagrfillet@gmail.com/ Link: https://lore.kernel.org/linux-riscv/d7d5730b-ebef-68e5-5046-e763e1ee6164@yadro.com/ Co-developed-by: Song Shuai <suagrfillet@gmail.com> Signed-off-by: Song Shuai <suagrfillet@gmail.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Cc: Evgenii Shatokhin <e.shatokhin@yadro.com> Reviewed-by: Evgenii Shatokhin <e.shatokhin@yadro.com> Link: https://lore.kernel.org/r/20230112090603.1295340-4-guoren@kernel.org Cc: stable@vger.kernel.org Fixes: 10626c32e382 ("riscv/ftrace: Add basic support") Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | Merge patch series "Remove toolchain dependencies for Zicbom"Palmer Dabbelt2023-02-142-1/+60
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conor Dooley <conor@kernel.org> says: From: Conor Dooley <conor.dooley@microchip.com> I've yoinked patch 1 from Drew's series adding support for Zicboz & attached two more patches here that remove the need for, and then drop the toolchain support checks for Zicbom. The goal is to remove the need for checking the presence of toolchain Zicbom support in the work being done to support non instruction based CMOs [1]. I've tested compliation on a number of different configurations with the Zicbom config option enabled. The important ones to call out I guess are: - clang/llvm 14 w/ LLVM=1 which doesn't support Zicbom atm. - gcc 11 w/ binutils 2.37 which doesn't support Zicbom atm either. - clang/llvm 15 w/ LLVM=1 BUT with binutils 2.37's ld. This is the configuration that prompted adding the LD checks as cc/as supports Zicbom, but ld doesn't [2]. - gcc 12 w/ binutils 2.39 & clang 15 w/ LLVM=1, both of these supported Zicbom before and still do. I also checked building the THEAD errata etc with CONFIG_RISCV_ISA_ZICBOM disabled, and there were no build issues there either. * b4-shazam-merge: RISC-V: remove toolchain version checks for Zicbom RISC-V: replace cbom instructions with an insn-def RISC-V: insn-def: Add I-type insn-def Link: https://lore.kernel.org/r/20230108163356.3063839-1-conor@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | RISC-V: replace cbom instructions with an insn-defConor Dooley2023-02-142-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using the cbom instructions directly in ALT_CMO_OP, requires toolchain support for the instructions. Using an insn-def will allow for removal of toolchain version checks in the build system & simplification of the proposed [1] function-based CMO scheme. Link: https://lore.kernel.org/linux-riscv/fb3b34ae-e35e-4dc2-a8f4-19984a2f58a8@app.fastmail.com/ [1] Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20230108163356.3063839-3-conor@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | RISC-V: insn-def: Add I-type insn-defAndrew Jones2023-02-141-0/+46
| | |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CBO instructions use the I-type of instruction format where the immediate is used to identify the CBO instruction type. Add I-type instruction encoding support to insn-def. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20230108163356.3063839-2-conor@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | Merge patch series "dt-bindings: Add a cpu-capacity property for RISC-V"Palmer Dabbelt2023-02-142-2/+2
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conor Dooley <conor@kernel.org> says: From: Conor Dooley <conor.dooley@microchip.com> Ever since RISC-V starting using generic arch topology code, the code paths for cpu-capacity have been there but there's no binding defined to actually convey the information. Defining the same property as used on arm seems to be the only logical thing to do, so do it. [Palmer: This is on top of the fix required to make it work, which itself wasn't merged until late in the 6.2 cycle and thus pulls in various other fixes.] * b4-shazam-merge: dt-bindings: riscv: add a capacity-dmips-mhz cpu property dt-bindings: arm: move cpu-capacity to a shared loation riscv: Move call to init_cpu_topology() to later initialization stage riscv/kprobe: Fix instruction simulation of JALR riscv: fix -Wundef warning for CONFIG_RISCV_BOOT_SPINWAIT MAINTAINERS: add an IRC entry for RISC-V RISC-V: fix compile error from deduplicated __ALTERNATIVE_CFG_2 dt-bindings: riscv: fix single letter canonical order dt-bindings: riscv: fix underscore requirement for multi-letter extensions riscv: uaccess: fix type of 0 variable on error in get_user() riscv, kprobes: Stricter c.jr/c.jalr decoding Link: https://lore.kernel.org/r/20230104180513.1379453-1-conor@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | | riscv: Fix Zbb alternative IDsSamuel Holland2023-02-141-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 4bf8860760d9 ("riscv: cpufeature: extend riscv_cpufeature_patch_func to all ISA extensions") switched ISA extension alternatives to use the RISCV_ISA_EXT_* macros instead of CPUFEATURE_*. This was mismerged when applied on top of the Zbb series, so the Zbb alternatives referenced the wrong errata ID values. Fixes: 9daca9a5b9ac ("Merge patch series "riscv: improve boot time isa extensions handling"") Signed-off-by: Samuel Holland <samuel@sholland.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Guo Ren <guoren@kernel.org> Tested-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230212021534.59121-3-samuel@sholland.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | | Merge patch series "riscv: improve boot time isa extensions handling"Palmer Dabbelt2023-02-018-69/+100
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jisheng Zhang <jszhang@kernel.org> says: Generally, riscv ISA extensions are fixed for any specific hardware platform, so a hart's features won't change after booting, this chacteristic makes it straightforward to use a static branch to check a specific ISA extension is supported or not to optimize performance. However, some ISA extensions such as SVPBMT and ZICBOM are handled via. the alternative sequences. Basically, for ease of maintenance, we prefer to use static branches in C code, but recently, Samuel found that the static branch usage in cpu_relax() breaks building with CONFIG_CC_OPTIMIZE_FOR_SIZE[1]. As Samuel pointed out, "Having a static branch in cpu_relax() is problematic because that function is widely inlined, including in some quite complex functions like in the VDSO. A quick measurement shows this static branch is responsible by itself for around 40% of the jump table." Samuel's findings pointed out one of a few downsides of static branches usage in C code to handle ISA extensions detected at boot time: static branch's metadata in the __jump_table section, which is not discarded after ISA extensions are finalized, wastes some space. I want to try to solve the issue for all possible dynamic handling of ISA extensions at boot time. Inspired by Mark[2], this patch introduces riscv_has_extension_*() helpers, which work like static branches but are patched using alternatives, thus the metadata can be freed after patching. [1]https://lore.kernel.org/linux-riscv/20220922060958.44203-1-samuel@sholland.org/ [2]https://lore.kernel.org/linux-arm-kernel/20220912162210.3626215-8-mark.rutland@arm.com/ [3]https://lore.kernel.org/linux-riscv/20221130225614.1594256-1-heiko@sntech.de/ * b4-shazam-merge: riscv: remove riscv_isa_ext_keys[] array and related usage riscv: KVM: Switch has_svinval() to riscv_has_extension_unlikely() riscv: cpu_relax: switch to riscv_has_extension_likely() riscv: alternative: patch alternatives in the vDSO riscv: switch to relative alternative entries riscv: module: Add ADD16 and SUB16 rela types riscv: module: move find_section to module.h riscv: fpu: switch has_fpu() to riscv_has_extension_likely() riscv: introduce riscv_has_extension_[un]likely() riscv: cpufeature: extend riscv_cpufeature_patch_func to all ISA extensions riscv: hwcap: make ISA extension ids can be used in asm riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlier riscv: move riscv_noncoherent_supported() out of ZICBOM probe Link: https://lore.kernel.org/r/20230128172856.3814-1-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | | riscv: remove riscv_isa_ext_keys[] array and related usageJisheng Zhang2023-01-311-32/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All users have switched to riscv_has_extension_*, remove unused definitions, vars and related setting code. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20230128172856.3814-14-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | | riscv: cpu_relax: switch to riscv_has_extension_likely()Jisheng Zhang2023-01-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch cpu_relax() from static branch to the new helper riscv_has_extension_likely() Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230128172856.3814-12-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | | riscv: alternative: patch alternatives in the vDSOJisheng Zhang2023-01-311-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make it possible to use alternatives in the vDSO, so that better implementations can be used if possible. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20230128172856.3814-11-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | | riscv: switch to relative alternative entriesJisheng Zhang2023-01-312-16/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of using absolute addresses for both the old instrucions and the alternative instructions, use offsets relative to the alt_entry values. So this not only cuts the size of the alternative entry, but also meets the prerequisite for patching alternatives in the vDSO, since absolute alternative entries are subject to dynamic relocation, which is incompatible with the vDSO building. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230128172856.3814-10-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | | riscv: module: move find_section to module.hJisheng Zhang2023-01-311-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move find_section() to module.h so that the implementation can be shared by the alternatives code. This will allow us to use alternatives in the vdso. Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Link: https://lore.kernel.org/r/20230128172856.3814-8-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | | riscv: fpu: switch has_fpu() to riscv_has_extension_likely()Jisheng Zhang2023-01-311-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch has_fpu() from static branch to the new helper riscv_has_extension_likely(). Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230128172856.3814-7-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | | riscv: introduce riscv_has_extension_[un]likely()Jisheng Zhang2023-01-311-0/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Generally, riscv ISA extensions are fixed for any specific hardware platform, so a hart's features won't change after booting. This chacteristic makes it straightforward to use a static branch to check if a specific ISA extension is supported or not to optimize performance. However, some ISA extensions such as SVPBMT and ZICBOM are handled via. the alternative sequences. Basically, for ease of maintenance, we prefer to use static branches in C code, but recently, Samuel found that the static branch usage in cpu_relax() breaks building with CONFIG_CC_OPTIMIZE_FOR_SIZE[1]. As Samuel pointed out, "Having a static branch in cpu_relax() is problematic because that function is widely inlined, including in some quite complex functions like in the VDSO. A quick measurement shows this static branch is responsible by itself for around 40% of the jump table." Samuel's findings pointed out one of a few downsides of static branches usage in C code to handle ISA extensions detected at boot time: static branch's metadata in the __jump_table section, which is not discarded after ISA extensions are finalized, wastes some space. I want to try to solve the issue for all possible dynamic handling of ISA extensions at boot time. Inspired by Mark[2], this patch introduces riscv_has_extension_*() helpers, which work like static branches but are patched using alternatives, thus the metadata can be freed after patching. Link: https://lore.kernel.org/linux-riscv/20220922060958.44203-1-samuel@sholland.org/ [1] Link: https://lore.kernel.org/linux-arm-kernel/20220912162210.3626215-8-mark.rutland@arm.com/ [2] Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230128172856.3814-6-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | | riscv: cpufeature: extend riscv_cpufeature_patch_func to all ISA extensionsJisheng Zhang2023-01-311-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | riscv_cpufeature_patch_func() currently only scans a limited set of cpufeatures, explicitly defined with macros. Extend it to probe for all ISA extensions. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230128172856.3814-5-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | | riscv: hwcap: make ISA extension ids can be used in asmJisheng Zhang2023-01-311-24/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So that ISA extensions can be used in assembly files, convert the multi-letter RISC-V ISA extension IDs enums to macros. In order to make them visible, move the #ifndef __ASSEMBLY__ guard to a later point in the header Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230128172856.3814-4-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | | | Merge patch series "Zbb string optimizations"Palmer Dabbelt2023-01-313-1/+13
| |\ \ \ \ \ \ | | |/ / / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Heiko Stuebner <heiko@sntech.de> says: From: Heiko Stuebner <heiko.stuebner@vrull.eu> This series still tries to allow optimized string functions for specific extensions. The last approach of using an inline base function to hold the alternative calls did cause some issues in a number of places So instead of that we're now just using an alternative j at the beginning of the generic function to jump to a separate place inside the function itself. * b4-shazam-merge: RISC-V: add zbb support to string functions RISC-V: add infrastructure to allow different str* implementations Link: https://lore.kernel.org/r/20230113212301.3534711-1-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | | RISC-V: add zbb support to string functionsHeiko Stuebner2023-01-312-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add handling for ZBB extension and add support for using it as a variant for optimized string functions. Support for the Zbb-str-variants is limited to the GNU-assembler for now, as LLVM has not yet acquired the functionality to selectively change the arch option in assembler code. This is still under review at https://reviews.llvm.org/D123515 Co-developed-by: Christoph Muellner <christoph.muellner@vrull.eu> Signed-off-by: Christoph Muellner <christoph.muellner@vrull.eu> Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230113212301.3534711-3-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | | RISC-V: add infrastructure to allow different str* implementationsHeiko Stuebner2023-01-311-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Depending on supported extensions on specific RISC-V cores, optimized str* functions might make sense. This adds basic infrastructure to allow patching the function calls via alternatives later on. The Linux kernel provides standard implementations for string functions but when architectures want to extend them, they need to provide their own. The added generic string functions are done in assembler (taken from disassembling the main-kernel functions for now) to allow us to control the used registers and extend them with optimized variants. This doesn't override the compiler's use of builtin replacements. So still first of all the compiler will select if a builtin will be better suitable i.e. for known strings. For all regular cases we will want to later select possible optimized variants and in the worst case fall back to the generic implemention added with this change. Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230113212301.3534711-2-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | | | RISC-V: Fix do_notify_resume / do_work_pending prototypeHeiko Stuebner2023-01-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit b0f4c74eadbf ("RISC-V: Fix unannoted hardirqs-on in return to userspace slow-path") renamed the do_notify_resume function to do_work_pending but did not change the prototype in signal.h Do that now, as the original function does not exist anymore. Fixes: b0f4c74eadbf ("RISC-V: Fix unannoted hardirqs-on in return to userspace slow-path") Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230118142252.337103-1-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | | | riscv: fix jal offsets in patched alternativesJisheng Zhang2023-01-241-0/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alternatives live in a different section, so offsets used by jal instruction will point to wrong locations after the patch got applied. Similar to arm64, adjust the location to consider that offset. Co-developed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230113212205.3534622-1-heiko@sntech.de Fixes: 27c653c06505 ("RISC-V: fix auipc-jalr addresses in patched alternatives") Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>