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2025-01-18Merge patch series "riscv: Add support for xtheadvector"Palmer Dabbelt
Charlie Jenkins <charlie@rivosinc.com> says: xtheadvector is a custom extension that is based upon riscv vector version 0.7.1 [1]. All of the vector routines have been modified to support this alternative vector version based upon whether xtheadvector was determined to be supported at boot. vlenb is not supported on the existing xtheadvector hardware, so a devicetree property thead,vlenb is added to provide the vlenb to Linux. There is a new hwprobe key RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 that is used to request which thead vendor extensions are supported on the current platform. This allows future vendors to allocate hwprobe keys for their vendor. Support for xtheadvector is also added to the vector kselftests. [1] https://github.com/T-head-Semi/thead-extension-spec/blob/95358cb2cca9489361c61d335e03d3134b14133f/xtheadvector.adoc * b4-shazam-merge: riscv: Add ghostwrite vulnerability selftests: riscv: Support xtheadvector in vector tests selftests: riscv: Fix vector tests riscv: hwprobe: Document thead vendor extensions and xtheadvector extension riscv: hwprobe: Add thead vendor extension probing riscv: vector: Support xtheadvector save/restore riscv: Add xtheadvector instruction definitions riscv: csr: Add CSR encodings for CSR_VXRM/CSR_VXSAT RISC-V: define the elements of the VCSR vector CSR riscv: vector: Use vlenb from DT for thead riscv: Add thead and xtheadvector as a vendor extension riscv: dts: allwinner: Add xtheadvector to the D1/D1s devicetree dt-bindings: cpus: add a thead vlen register length property dt-bindings: riscv: Add xtheadvector ISA extension description Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-0-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2025-01-18riscv: vector: Support xtheadvector save/restoreCharlie Jenkins
Use alternatives to add support for xtheadvector vector save/restore routines. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-9-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2025-01-18riscv: csr: Add CSR encodings for CSR_VXRM/CSR_VXSATCharlie Jenkins
The VXRM vector csr for xtheadvector has an encoding of 0xa and VXSAT has an encoding of 0x9. Co-developed-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-7-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2025-01-18RISC-V: define the elements of the VCSR vector CSRHeiko Stuebner
The VCSR CSR contains two elements VXRM[2:1] and VXSAT[0]. Define constants for those to access the elements in a readable way. Acked-by: Guo Ren <guoren@kernel.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-6-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-11-27Merge tag 'kvm-riscv-6.13-2' of https://github.com/kvm-riscv/linux into HEADPaolo Bonzini
KVM/riscv changes for 6.13 part #2 - Svade and Svadu extension support for Host and Guest/VM
2024-11-21RISC-V: Add Svade and Svadu Extensions SupportYong-Xuan Wang
Svade and Svadu extensions represent two schemes for managing the PTE A/D bits. When the PTE A/D bits need to be set, Svade extension intdicates that a related page fault will be raised. In contrast, the Svadu extension supports hardware updating of PTE A/D bits. Since the Svade extension is mandatory and the Svadu extension is optional in RVA23 profile, by default the M-mode firmware will enable the Svadu extension in the menvcfg CSR when only Svadu is present in DT. This patch detects Svade and Svadu extensions from DT and adds arch_has_hw_pte_young() to enable optimization in MGLRU and __wp_page_copy_user() when we have the PTE A/D bits hardware updating support. Co-developed-by: Jinyu Tang <tjytimi@163.com> Signed-off-by: Jinyu Tang <tjytimi@163.com> Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20240726084931.28924-2-yongxuan.wang@sifive.com Signed-off-by: Anup Patel <anup@brainfault.org>
2024-10-24riscv: Add CSR definitions for pointer maskingSamuel Holland
Pointer masking is controlled via a two-bit PMM field, which appears in various CSRs depending on which extensions are implemented. Smmpm adds the field to mseccfg; Smnpm adds the field to menvcfg; Ssnpm adds the field to senvcfg. If the H extension is implemented, Ssnpm also defines henvcfg.PMM and hstatus.HUPMM. Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20241016202814.4061541-4-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-04-26RISC-V: KVM: Add perf sampling support for guestsAtish Patra
KVM enables perf for guest via counter virtualization. However, the sampling can not be supported as there is no mechanism to enabled trap/emulate scountovf in ISA yet. Rely on the SBI PMU snapshot to provide the counter overflow data via the shared memory. In case of sampling event, the host first sets the guest's LCOFI interrupt and injects to the guest via irq filtering mechanism defined in AIA specification. Thus, ssaia must be enabled in the host in order to use perf sampling in the guest. No other AIA dependency w.r.t kernel is required. Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20240420151741.962500-15-atishp@rivosinc.com Signed-off-by: Anup Patel <anup@brainfault.org>
2024-04-22RISC-V: Fix the typo in Scountovf CSR nameAtish Patra
The counter overflow CSR name is "scountovf" not "sscountovf". Fix the csr name. Fixes: 4905ec2fb7e6 ("RISC-V: Add sscofpmf extension support") Reviewed-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Acked-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20240420151741.962500-2-atishp@rivosinc.com Signed-off-by: Anup Patel <anup@brainfault.org>
2024-02-29riscv: Fix enabling cbo.zero when running in M-modeSamuel Holland
When the kernel is running in M-mode, the CBZE bit must be set in the menvcfg CSR, not in senvcfg. Cc: <stable@vger.kernel.org> Fixes: 43c16d51a19b ("RISC-V: Enable cbo.zero in usermode") Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240228065559.3434837-2-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-17RISC-V: Implement archrandom when Zkr is availableSamuel Ortiz
The Zkr extension is ratified and provides 16 bits of entropy seed when reading the SEED CSR. We can implement arch_get_random_seed_longs() by doing multiple csrrw to that CSR and filling an unsigned long with valid entropy bits. Acked-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Samuel Ortiz <sameo@rivosinc.com> Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231130111704.1319081-1-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-10-12RISCV: KVM: Add sstateen0 context save/restoreMayuresh Chitale
Define sstateen0 and add sstateen0 save/restore for guest VCPUs. Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-10-12RISCV: KVM: Add senvcfg context save/restoreMayuresh Chitale
Add senvcfg context save/restore for guest VCPUs and also add it to the ONE_REG interface to allow its access from user space. Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-10-12RISC-V: KVM: Enable Smstateen accessesMayuresh Chitale
Configure hstateen0 register so that the AIA state and envcfg are accessible to the vcpus. This includes registers such as siselect, sireg, siph, sieh and all the IMISC registers. Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-08-08RISC-V: KVM: provide UAPI for host SATP modeDaniel Henrique Barboza
KVM userspaces need to be aware of the host SATP to allow them to advertise it back to the guest OS. Since this information is used to build the guest FDT we can't wait for the SATP reg to be readable. We just need to read the SATP mode, thus we can use the existing 'satp_mode' global that represents the SATP reg with MODE set and both ASID and PPN cleared. E.g. for a 32 bit host running with sv32 satp_mode is 0x80000000, for a 64 bit host running sv57 satp_mode is 0xa000000000000000, and so on. Add a new userspace virtual config register 'satp_mode' to allow userspace to read the current SATP mode the host is using with GET_ONE_REG API before spinning the vcpu. 'satp_mode' can't be changed via KVM, so SET_ONE_REG is allowed as long as userspace writes the existing 'satp_mode'. Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-07-03Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM64: - Eager page splitting optimization for dirty logging, optionally allowing for a VM to avoid the cost of hugepage splitting in the stage-2 fault path. - Arm FF-A proxy for pKVM, allowing a pKVM host to safely interact with services that live in the Secure world. pKVM intervenes on FF-A calls to guarantee the host doesn't misuse memory donated to the hyp or a pKVM guest. - Support for running the split hypervisor with VHE enabled, known as 'hVHE' mode. This is extremely useful for testing the split hypervisor on VHE-only systems, and paves the way for new use cases that depend on having two TTBRs available at EL2. - Generalized framework for configurable ID registers from userspace. KVM/arm64 currently prevents arbitrary CPU feature set configuration from userspace, but the intent is to relax this limitation and allow userspace to select a feature set consistent with the CPU. - Enable the use of Branch Target Identification (FEAT_BTI) in the hypervisor. - Use a separate set of pointer authentication keys for the hypervisor when running in protected mode, as the host is untrusted at runtime. - Ensure timer IRQs are consistently released in the init failure paths. - Avoid trapping CTR_EL0 on systems with Enhanced Virtualization Traps (FEAT_EVT), as it is a register commonly read from userspace. - Erratum workaround for the upcoming AmpereOne part, which has broken hardware A/D state management. RISC-V: - Redirect AMO load/store misaligned traps to KVM guest - Trap-n-emulate AIA in-kernel irqchip for KVM guest - Svnapot support for KVM Guest s390: - New uvdevice secret API - CMM selftest and fixes - fix racy access to target CPU for diag 9c x86: - Fix missing/incorrect #GP checks on ENCLS - Use standard mmu_notifier hooks for handling APIC access page - Drop now unnecessary TR/TSS load after VM-Exit on AMD - Print more descriptive information about the status of SEV and SEV-ES during module load - Add a test for splitting and reconstituting hugepages during and after dirty logging - Add support for CPU pinning in demand paging test - Add support for AMD PerfMonV2, with a variety of cleanups and minor fixes included along the way - Add a "nx_huge_pages=never" option to effectively avoid creating NX hugepage recovery threads (because nx_huge_pages=off can be toggled at runtime) - Move handling of PAT out of MTRR code and dedup SVM+VMX code - Fix output of PIC poll command emulation when there's an interrupt - Add a maintainer's handbook to document KVM x86 processes, preferred coding style, testing expectations, etc. - Misc cleanups, fixes and comments Generic: - Miscellaneous bugfixes and cleanups Selftests: - Generate dependency files so that partial rebuilds work as expected" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (153 commits) Documentation/process: Add a maintainer handbook for KVM x86 Documentation/process: Add a label for the tip tree handbook's coding style KVM: arm64: Fix misuse of KVM_ARM_VCPU_POWER_OFF bit index RISC-V: KVM: Remove unneeded semicolon RISC-V: KVM: Allow Svnapot extension for Guest/VM riscv: kvm: define vcpu_sbi_ext_pmu in header RISC-V: KVM: Expose IMSIC registers as attributes of AIA irqchip RISC-V: KVM: Add in-kernel virtualization of AIA IMSIC RISC-V: KVM: Expose APLIC registers as attributes of AIA irqchip RISC-V: KVM: Add in-kernel emulation of AIA APLIC RISC-V: KVM: Implement device interface for AIA irqchip RISC-V: KVM: Skeletal in-kernel AIA irqchip support RISC-V: KVM: Set kvm_riscv_aia_nr_hgei to zero RISC-V: KVM: Add APLIC related defines RISC-V: KVM: Add IMSIC related defines RISC-V: KVM: Implement guest external interrupt line management KVM: x86: Remove PRIx* definitions as they are solely for user space s390/uv: Update query for secret-UVCs s390/uv: replace scnprintf with sysfs_emit s390/uvdevice: Add 'Lock Secret Store' UVC ...
2023-06-08riscv: Add new csr defines related to vector extensionGreentime Hu
Follow the riscv vector spec to add new csr numbers. Acked-by: Guo Ren <guoren@kernel.org> Co-developed-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Co-developed-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Suggested-by: Vineet Gupta <vineetg@rivosinc.com> Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230605110724.21391-5-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-06RISC-V: KVM: Redirect AMO load/store misaligned traps to guestwchen
The M-mode redirects an unhandled misaligned trap back to S-mode when not delegating it to VS-mode(hedeleg). However, KVM running in HS-mode terminates the VS-mode software when back from M-mode. The KVM should redirect the trap back to VS-mode, and let VS-mode trap handler decide the next step. Here is a way to handle misaligned traps in KVM, not only directing them to VS-mode or terminate it. Signed-off-by: wchen <waylingII@gmail.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-05-05Merge tag 'kvm-riscv-6.4-1' of https://github.com/kvm-riscv/linux into HEADPaolo Bonzini
KVM/riscv changes for 6.4 - ONE_REG interface to enable/disable SBI extensions - Zbb extension for Guest/VM - AIA CSR virtualization
2023-04-21RISC-V: KVM: Drop the _MASK suffix from hgatp.VMID mask definesAnup Patel
The hgatp.VMID mask defines are used before shifting when extracting VMID value from hgatp CSR value so based on the convention followed in the other parts of asm/csr.h, the hgatp.VMID mask defines should not have a _MASK suffix. While we are here, let's use GENMASK() for hgatp.VMID and hgatp.PPN. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2023-04-21RISC-V: Add AIA related CSR definesAnup Patel
The RISC-V AIA specification improves handling per-HART local interrupts in a backward compatible manner. This patch adds defines for new RISC-V AIA CSRs. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org> Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-03-23riscv: entry: Convert to generic entryGuo Ren
This patch converts riscv to use the generic entry infrastructure from kernel/entry/*. The generic entry makes maintainers' work easier and codes more elegant. Here are the changes: - More clear entry.S with handle_exception and ret_from_exception - Get rid of complex custom signal implementation - Move syscall procedure from assembly to C, which is much more readable. - Connect ret_from_fork & ret_from_kernel_thread to generic entry. - Wrap with irqentry_enter/exit and syscall_enter/exit_from_user_mode - Use the standard preemption code instead of custom Suggested-by: Huacai Chen <chenhuacai@kernel.org> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Yipeng Zou <zouyipeng@huawei.com> Tested-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Cc: Ben Hutchings <ben@decadent.org.uk> Link: https://lore.kernel.org/r/20230222033021.983168-5-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-08-11RISC-V: Add Sstc extension supportPalmer Dabbelt
This series implements Sstc extension support which was ratified recently. Before the Sstc extension, an SBI call is necessary to generate timer interrupts as only M-mode have access to the timecompare registers. Thus, there is significant latency to generate timer interrupts at kernel. For virtualized enviornments, its even worse as the KVM handles the SBI call and uses a software timer to emulate the timecomapre register. Sstc extension solves both these problems by defining a stimecmp/vstimecmp at supervisor (host/guest) level. It allows kernel to program a timer and recieve interrupt without supervisor execution enviornment (M-mode/HS mode) intervention. * palmer/riscv-sstc: RISC-V: Prefer sstc extension if available RISC-V: Enable sstc extension parsing from DT RISC-V: Add SSTC extension CSR details
2022-08-11RISC-V: Add SSTC extension CSR detailsAtish Patra
This patch just introduces the required CSR fields related to the SSTC extension. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20220722165047.519994-2-atishp@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-29RISC-V: KVM: Add support for Svpbmt inside Guest/VMAnup Patel
The Guest/VM can use Svpbmt in VS-stage page tables when allowed by the Hypervisor using the henvcfg.PBMTE bit. We add Svpbmt support for the KVM Guest/VM which can be enabled/disabled by the KVM user-space (QEMU/KVMTOOL) using the ISA extension ONE_REG interface. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-05-31Merge tag 'riscv-for-linus-5.19-mw0' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support for the Svpbmt extension, which allows memory attributes to be encoded in pages - Support for the Allwinner D1's implementation of page-based memory attributes - Support for running rv32 binaries on rv64 systems, via the compat subsystem - Support for kexec_file() - Support for the new generic ticket-based spinlocks, which allows us to also move to qrwlock. These should have already gone in through the asm-geneic tree as well - A handful of cleanups and fixes, include some larger ones around atomics and XIP * tag 'riscv-for-linus-5.19-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (51 commits) RISC-V: Prepare dropping week attribute from arch_kexec_apply_relocations[_add] riscv: compat: Using seperated vdso_maps for compat_vdso_info RISC-V: Fix the XIP build RISC-V: Split out the XIP fixups into their own file RISC-V: ignore xipImage RISC-V: Avoid empty create_*_mapping definitions riscv: Don't output a bogus mmu-type on a no MMU kernel riscv: atomic: Add custom conditional atomic operation implementation riscv: atomic: Optimize dec_if_positive functions riscv: atomic: Cleanup unnecessary definition RISC-V: Load purgatory in kexec_file RISC-V: Add purgatory RISC-V: Support for kexec_file on panic RISC-V: Add kexec_file support RISC-V: use memcpy for kexec_file mode kexec_file: Fix kexec_file.c build error for riscv platform riscv: compat: Add COMPAT Kbuild skeletal support riscv: compat: ptrace: Add compat_arch_ptrace implement riscv: compat: signal: Add rt_frame implementation riscv: add memory-type errata for T-Head ...
2022-05-20RISC-V: KVM: Add Sv57x4 mode support for G-stageAnup Patel
Latest QEMU supports G-stage Sv57x4 mode so this patch extends KVM RISC-V G-stage handling to detect and use Sv57x4 mode when available. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-04-26riscv: compat: syscall: Add entry.S implementationGuo Ren
Implement the entry of compat_sys_call_table[] in asm. Ref to riscv-privileged spec 4.1.1 Supervisor Status Register (sstatus): BIT[32:33] = UXL[1:0]: - 1:32 - 2:64 - 3:128 Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Signed-off-by: Guo Ren <guoren@kernel.org> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Tested-by: Heiko Stuebner <heiko@sntech.de> Link: https://lore.kernel.org/r/20220405071314.3225832-13-guoren@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-21perf: RISC-V: Add support for SBI PMU and SscofpmfPalmer Dabbelt
This series improves perf support for RISC-V based system using SBI PMU and Sscofpmf extensions, by adding a new generic RISC-V perf framework along with a pair of drivers: one that usese the new performance-monitoring extensions and one that keeps support for the existing systems that only have the legacy counters. Tested-by: Nikita Shubin <n.shubin@yadro.com> * palmer/riscv-pmu: MAINTAINERS: Add entry for RISC-V PMU drivers Documentation: riscv: Remove the old documentation RISC-V: Add sscofpmf extension support RISC-V: Add perf platform driver based on SBI PMU extension RISC-V: Add RISC-V SBI PMU extension definitions RISC-V: Add a simple platform driver for RISC-V legacy perf RISC-V: Add a perf core library for pmu drivers RISC-V: Add CSR encodings for all HPMCOUNTERS RISC-V: Remove the current perf implementation
2022-03-21RISC-V: Add sscofpmf extension supportAtish Patra
The sscofpmf extension allows counter overflow and filtering for programmable counters. Enable the perf driver to handle the overflow interrupt. The overflow interrupt is a hart local interrupt. Thus, per cpu overflow interrupts are setup as a child under the root INTC irq domain. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-21RISC-V: Add CSR encodings for all HPMCOUNTERSAtish Patra
Linux kernel can directly read these counters as the HPMCOUNTERS CSRs are accessible in S-mode. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-02-14riscv: mm: Set sv57 on defaultlyQinglin Pan
This patch sets sv57 on defaultly if CONFIG_64BIT. And do fallback to try to set sv48 on boot time if sv57 is not supported in current hardware. Signed-off-by: Qinglin Pan <panqinglin2020@iscas.ac.cn> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-01-19riscv: Implement sv48 supportAlexandre Ghiti
By adding a new 4th level of page table, give the possibility to 64bit kernel to address 2^48 bytes of virtual address: in practice, that offers 128TB of virtual address space to userspace and allows up to 64TB of physical memory. If the underlying hardware does not support sv48, we will automatically fallback to a standard 3-level page table by folding the new PUD level into PGDIR level. In order to detect HW capabilities at runtime, we use SATP feature that ignores writes with an unsupported mode. Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2021-10-04RISC-V: Add hypervisor extension related CSR definesAnup Patel
This patch adds asm/kvm_csr.h for RISC-V hypervisor extension related defines. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Alexander Graf <graf@amazon.com> Message-Id: <20210927114016.1089328-2-anup.patel@wdc.com> Acked-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-04-26riscv: Introduce alternative mechanism to apply errata solutionVincent Chen
Introduce the "alternative" mechanism from ARM64 and x86 to apply the CPU vendors' errata solution at runtime. The main purpose of this patch is to provide a framework. Therefore, the implementation is quite basic for now so that some scenarios could not use this schemei, such as patching code to a module, relocating the patching code and heterogeneous CPU topology. Users could use the macro ALTERNATIVE to apply an errata to the existing code flow. In the macro ALTERNATIVE, users need to specify the manufacturer information(vendorid, archid, and impid) for this errata. Therefore, kernel will know this errata is suitable for which CPU core. During the booting procedure, kernel will select the errata required by the CPU core and then patch it. It means that the kernel only applies the errata to the specified CPU core. In this case, the vendor's errata does not affect each other at runtime. The above patching procedure only occurs during the booting phase, so we only take the overhead of the "alternative" mechanism once. This "alternative" mechanism is enabled by default to ensure that all required errata will be applied. However, users can disable this feature by the Kconfig "CONFIG_RISCV_ERRATA_ALTERNATIVE". Signed-off-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-02-18RISC-V: Implement ASID allocatorAnup Patel
Currently, we do local TLB flush on every MM switch. This is very harsh on performance because we are forcing page table walks after every MM switch. This patch implements ASID allocator for assigning an ASID to a MM context. The number of ASIDs are limited in HW so we create a logical entity named CONTEXTID for assigning to MM context. The lower bits of CONTEXTID are ASID and upper bits are VERSION number. The number of usable ASID bits supported by HW are detected at boot-time by writing 1s to ASID bits in SATP CSR. We allocate new CONTEXTID on first MM switch for a MM context where the ASID is allocated from an ASID bitmap and VERSION is provide by an atomic counter. At time of allocating new CONTEXTID, if we run out of available ASIDs then: 1. We flush the ASID bitmap 2. Increment current VERSION atomic counter 3. Re-allocate ASID from ASID bitmap 4. Flush TLB on all CPUs 5. Try CONTEXTID re-assignment on all CPUs Please note that we don't use ASID #0 because it is used at boot-time by all CPUs for initial MM context. Also, newly created context is always assigned CONTEXTID #0 (i.e. VERSION #0 and ASID #0) which is an invalid context in our implementation. Using above approach, we have virtually infinite CONTEXTIDs on-top-of limited number of HW ASIDs. This approach is inspired from ASID allocator used for Linux ARM/ARM64 but we have adapted it for RISC-V. Overall, this ASID allocator helps us reduce rate of local TLB flushes on every CPU thereby increasing performance. This patch is tested on QEMU virt machine, Spike and SiFive Unleashed board. On QEMU virt machine, we see some (3-5% approx) performance improvement with SW emulated TLBs provided by QEMU. Unfortunately, the ASID bits of the SATP CSR are not implemented on Spike and SiFive Unleashed board so we don't see any change in performance. On real HW having all ASID bits implemented, the performance gains will be much more due improved sharing of TLB among different processes. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-05-04RISC-V: Remove N-extension related definesAnup Patel
The RISC-V N-extension is still in draft state hence remove N-extension related defines from asm/csr.h. Signed-off-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-02-18riscv: set pmp configuration if kernel is running in M-modeGreentime Hu
When the kernel is running in S-mode, the expectation is that the bootloader or SBI layer will configure the PMP to allow the kernel to access physical memory. But, when the kernel is running in M-mode and is started with the ELF "loader", there's probably no bootloader or SBI layer involved to configure the PMP. Thus, we need to configure the PMP ourselves to enable the kernel to access all regions. Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-01-04riscv: prefix IRQ_ macro names with an RV_ namespacePaul Walmsley
"IRQ_TIMER", used in the arch/riscv CSR header file, is a sufficiently generic macro name that it's used by several source files across the Linux code base. Some of these other files ultimately include the arch/riscv CSR include file, causing collisions. Fix by prefixing the RISC-V csr.h IRQ_ macro names with an RV_ prefix. Fixes: a4c3733d32a72 ("riscv: abstract out CSR names for supervisor vs machine mode") Reported-by: Olof Johansson <olof@lixom.net> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-17riscv: clear the instruction cache and all registers when bootingChristoph Hellwig
When we get booted we want a clear slate without any leaks from previous supervisors or the firmware. Flush the instruction cache and then clear all registers to known good values. This is really important for the upcoming nommu support that runs on M-mode, but can't really harm when running in S-mode either. Vaguely based on the concepts from opensbi. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-17riscv: read the hart ID from mhartid on bootDamien Le Moal
When in M-Mode, we can use the mhartid CSR to get the ID of the running HART. Doing so, direct M-Mode boot without firmware is possible. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-11-05riscv: abstract out CSR names for supervisor vs machine modeChristoph Hellwig
Many of the privileged CSRs exist in a supervisor and machine version that are used very similarly. Provide versions of the CSR names and fields that map to either the S-mode or M-mode variant depending on a new CONFIG_RISCV_M_MODE kconfig symbol. Contains contributions from Damien Le Moal <Damien.LeMoal@wdc.com> and Paul Walmsley <paul.walmsley@sifive.com>. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> # for drivers/clocksource, drivers/irqchip [paul.walmsley@sifive.com: updated to apply] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 286Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 97 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.025053186@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-16RISC-V: Access CSRs using CSR numbersAnup Patel
We should prefer accessing CSRs using their CSR numbers because: 1. It compiles fine with older toolchains. 2. We can use latest CSR names in #define macro names of CSR numbers as-per RISC-V spec. 3. We can access newly added CSRs even if toolchain does not recognize newly addes CSRs by name. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-05-16RISC-V: Add interrupt related SCAUSE defines in asm/csr.hAnup Patel
This patch adds SCAUSE interrupt flag and SCAUSE interrupt related defines to asm/csr.h. We also use these defines in kernel/irq.c and express SIE/SIP flags in-terms of SCAUSE interrupt causes. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-05-16RISC-V: Use tabs to align macro values in asm/csr.hAnup Patel
The spacing between macro name and value is not consistent in asm/csr.h. This patch beautifies asm/csr.h by using tabs to align macro values instead of spaces. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-08-13RISC-V: add a definition for the SIE SEIE bitChristoph Hellwig
This mirrors the SIE_SSIE and SETE bits that are used in a similar fashion. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-30riscv: rename sptbr to satpChristoph Hellwig
satp is the name used by the current privileged spec 1.10, use it instead of the old name. The most recent release binutils release (2.29) doesn't know about the satp name yet, so stick to the name from the previous privileged ISA release and comment on the fact. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-01-07riscv: rename SR_* constants to match the specChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-09-26RISC-V: Generic library routines and assemblyPalmer Dabbelt
This patch contains code that is more specific to the RISC-V ISA than it is to Linux. It contains string and math operations, C wrappers for various assembly instructions, stack walking code, and uaccess. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>