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2025-01-31Merge tag 'riscv-for-linus-6.14-mw1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - The PH1520 pinctrl and dwmac drivers are enabeled in defconfig - A redundant AQRL barrier has been removed from the futex cmpxchg implementation - Support for the T-Head vector extensions, which includes exposing these extensions to userspace on systems that implement them - Some more page table information is now printed on die() and systems that cause PA overflows * tag 'riscv-for-linus-6.14-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: add a warning when physical memory address overflows riscv/mm/fault: add show_pte() before die() 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 RISC-V: Mark riscv_v_init() as __init riscv: defconfig: drop RT_GROUP_SCHED=y riscv/futex: Optimize atomic cmpxchg riscv: defconfig: enable pinctrl and dwmac support for TH1520
2025-01-28treewide: const qualify ctl_tables where applicableJoel Granados
Add the const qualifier to all the ctl_tables in the tree except for watchdog_hardlockup_sysctl, memory_allocation_profiling_sysctls, loadpin_sysctl_table and the ones calling register_net_sysctl (./net, drivers/inifiniband dirs). These are special cases as they use a registration function with a non-const qualified ctl_table argument or modify the arrays before passing them on to the registration function. Constifying ctl_table structs will prevent the modification of proc_handler function pointers as the arrays would reside in .rodata. This is made possible after commit 78eb4ea25cd5 ("sysctl: treewide: constify the ctl_table argument of proc_handlers") constified all the proc_handlers. Created this by running an spatch followed by a sed command: Spatch: virtual patch @ depends on !(file in "net") disable optional_qualifier @ identifier table_name != { watchdog_hardlockup_sysctl, iwcm_ctl_table, ucma_ctl_table, memory_allocation_profiling_sysctls, loadpin_sysctl_table }; @@ + const struct ctl_table table_name [] = { ... }; sed: sed --in-place \ -e "s/struct ctl_table .table = &uts_kern/const struct ctl_table *table = \&uts_kern/" \ kernel/utsname_sysctl.c Reviewed-by: Song Liu <song@kernel.org> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> # for kernel/trace/ Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> # SCSI Reviewed-by: Darrick J. Wong <djwong@kernel.org> # xfs Acked-by: Jani Nikula <jani.nikula@intel.com> Acked-by: Corey Minyard <cminyard@mvista.com> Acked-by: Wei Liu <wei.liu@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Bill O'Donnell <bodonnel@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com> Acked-by: Anna Schumaker <anna.schumaker@oracle.com> Signed-off-by: Joel Granados <joel.granados@kernel.org>
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: vector: Use vlenb from DT for theadCharlie Jenkins
If thead,vlenb is provided in the device tree, prefer that over reading the vlenb csr. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-5-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2025-01-18RISC-V: Mark riscv_v_init() as __initPalmer Dabbelt
This trips up with Xtheadvector enabled, but as far as I can tell it's just been an issue since the original patchset. Fixes: 7ca7a7b9b635 ("riscv: Add sysctl to set the default vector rule for new processes") Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20250115180251.31444-1-palmer@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-10-18RISC-V: Detect unaligned vector accesses supportedJesse Taube
Run an unaligned vector access to test if the system supports vector unaligned access. Add the result to a new key in hwprobe. This is useful for usermode to know if vector misaligned accesses are supported and if they are faster or slower than equivalent byte accesses. Signed-off-by: Jesse Taube <jesse@rivosinc.com> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20241017-jesse_unaligned_vector-v10-4-5b33500160f8@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-30riscv: vector: adjust minimum Vector requirement to ZVE32XAndy Chiu
Make has_vector() to check for ZVE32X. Every in-kernel usage of V that requires a more complicate version of V must then call out explicitly. Also, change riscv_v_first_use_handler(), and boot code that calls riscv_v_setup_vsize() to accept ZVE32X. Most kernel/user interfaces requires minimum of ZVE32X. Thus, programs compiled and run with ZVE32X should be supported by the kernel on most aspects. This includes context-switch, signal, ptrace, prctl, and hwprobe. One exception is that ELF_HWCAP returns 'V' only if full V is supported on the platform. This means that the system without a full V must not rely on ELF_HWCAP to tell whether it is allowable to execute Vector without first invoking a prctl() check. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Joel Granados <j.granados@samsung.com> Link: https://lore.kernel.org/r/20240510-zve-detection-v5-7-0711bdd26c12@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-16riscv: vector: allow kernel-mode Vector with preemptionAndy Chiu
Add kernel_vstate to keep track of kernel-mode Vector registers when trap introduced context switch happens. Also, provide riscv_v_flags to let context save/restore routine track context status. Context tracking happens whenever the core starts its in-kernel Vector executions. An active (dirty) kernel task's V contexts will be saved to memory whenever a trap-introduced context switch happens. Or, when a softirq, which happens to nest on top of it, uses Vector. Context retoring happens when the execution transfer back to the original Kernel context where it first enable preempt_v. Also, provide a config CONFIG_RISCV_ISA_V_PREEMPTIVE to give users an option to disable preemptible kernel-mode Vector at build time. Users with constraint memory may want to disable this config as preemptible kernel-mode Vector needs extra space for tracking of per thread's kernel-mode V context. Or, users might as well want to disable it if all kernel-mode Vector code is time sensitive and cannot tolerate context switch overhead. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-16riscv: vector: use kmem_cache to manage vector contextAndy Chiu
The allocation size of thread.vstate.datap is always riscv_v_vsize. So it is possbile to use kmem_cache_* to manage the allocation. This gives users more information regarding allocation of vector context via /proc/slabinfo. And it potentially reduces the latency of the first-use trap because of the allocation caches. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-16riscv: vector: use a mask to write vstate_ctrlAndy Chiu
riscv_v_ctrl_set() should only touch bits within PR_RISCV_V_VSTATE_CTRL_MASK. So, use the mask when we really set task's vstate_ctrl. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-9-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-16riscv: sched: defer restoring Vector context for userAndy Chiu
User will use its Vector registers only after the kernel really returns to the userspace. So we can delay restoring Vector registers as long as we are still running in kernel mode. So, add a thread flag to indicates the need of restoring Vector and do the restore at the last arch-specific exit-to-user hook. This save the context restoring cost when we switch over multiple processes that run V in kernel mode. For example, if the kernel performs a context swicth from A->B->C, and returns to C's userspace, then there is no need to restore B's V-register. Besides, this also prevents us from repeatedly restoring V context when executing kernel-mode Vector multiple times. The cost of this is that we must disable preemption and mark vector as busy during vstate_{save,restore}. Because then the V context will not get restored back immediately when a trap-causing context switch happens in the middle of vstate_{save,restore}. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/20240115055929.4736-5-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-10-10riscv: Remove now superfluous sentinel element from ctl_table arrayJoel Granados
This commit comes at the tail end of a greater effort to remove the empty elements at the end of the ctl_table arrays (sentinels) which will reduce the overall build time size of the kernel and run time memory bloat by ~64 bytes per sentinel (further information Link : https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/) Remove sentinel element from riscv_v_default_vstate_table. This removal is safe because register_sysctl implicitly uses ARRAY_SIZE() in addition to checking for the sentinel. Signed-off-by: Joel Granados <j.granados@samsung.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-07-01riscv: vector: clear V-reg in the first-use trapAndy Chiu
If there is no context switch happens after we enable V for a process, then we return to user space with whatever left on the CPU's V registers accessible to the process. The leaked data could belong to another process's V-context saved from last context switch, impacting process's confidentiality on the system. To prevent this from happening, we clear V registers by restoring zero'd V context after turining on V. Fixes: cd054837243b ("riscv: Allocate user's vector context in the first-use trap") Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230627015556.12329-2-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-08riscv: Add sysctl to set the default vector rule for new processesAndy Chiu
To support Vector extension, the series exports variable-length vector registers on the signal frame. However, this potentially breaks abi if processing vector registers is required in the signal handler for old binaries. For example, there is such need if user-level context switch is triggerred via signals[1]. For this reason, it is best to leave a decision to distro maintainers, where the enablement of userspace Vector for new launching programs can be controlled. Developers may also need the switch to experiment with. The parameter is configurable through sysctl interface so a distro may turn off Vector early at init script if the break really happens in the wild. The switch will only take effects on new execve() calls once set. This will not effect existing processes that do not call execve(), nor processes which has been set with a non-default vstate_ctrl by making explicit PR_RISCV_V_SET_CONTROL prctl() calls. Link: https://lore.kernel.org/all/87cz4048rp.fsf@all.your.base.are.belong.to.us/ Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Greentime Hu <greentime.hu@sifive.com> Reviewed-by: Vincent Chen <vincent.chen@sifive.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-23-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-08riscv: Add prctl controls for userspace vector managementAndy Chiu
This patch add two riscv-specific prctls, to allow usespace control the use of vector unit: * PR_RISCV_V_SET_CONTROL: control the permission to use Vector at next, or all following execve for a thread. Turning off a thread's Vector live is not possible since libraries may have registered ifunc that may execute Vector instructions. * PR_RISCV_V_GET_CONTROL: get the same permission setting for the current thread, and the setting for following execve(s). Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Greentime Hu <greentime.hu@sifive.com> Reviewed-by: Vincent Chen <vincent.chen@sifive.com> Link: https://lore.kernel.org/r/20230605110724.21391-22-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-08riscv: Allocate user's vector context in the first-use trapAndy Chiu
Vector unit is disabled by default for all user processes. Thus, a process will take a trap (illegal instruction) into kernel at the first time when it uses Vector. Only after then, the kernel allocates V context and starts take care of the context for that user process. Suggested-by: Richard Henderson <richard.henderson@linaro.org> Link: https://lore.kernel.org/r/3923eeee-e4dc-0911-40bf-84c34aee962d@linaro.org Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230605110724.21391-12-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-08riscv: Introduce riscv_v_vsize to record size of Vector contextGreentime Hu
This patch is used to detect the size of CPU vector registers and use riscv_v_vsize to save the size of all the vector registers. It assumes all harts has the same capabilities in a SMP system. If a core detects VLENB that is different from the boot core, then it warns and turns off V support for user space. 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> 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> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-9-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>