diff options
Diffstat (limited to 'arch/riscv/include/asm')
| -rw-r--r-- | arch/riscv/include/asm/asm-prototypes.h | 27 | ||||
| -rw-r--r-- | arch/riscv/include/asm/entry-common.h | 17 | ||||
| -rw-r--r-- | arch/riscv/include/asm/processor.h | 41 | ||||
| -rw-r--r-- | arch/riscv/include/asm/simd.h | 64 | ||||
| -rw-r--r-- | arch/riscv/include/asm/switch_to.h | 3 | ||||
| -rw-r--r-- | arch/riscv/include/asm/thread_info.h | 2 | ||||
| -rw-r--r-- | arch/riscv/include/asm/vector.h | 90 | ||||
| -rw-r--r-- | arch/riscv/include/asm/xor.h | 68 |
8 files changed, 298 insertions, 14 deletions
diff --git a/arch/riscv/include/asm/asm-prototypes.h b/arch/riscv/include/asm/asm-prototypes.h index 36b955c762ba..cd627ec289f1 100644 --- a/arch/riscv/include/asm/asm-prototypes.h +++ b/arch/riscv/include/asm/asm-prototypes.h @@ -9,6 +9,33 @@ long long __lshrti3(long long a, int b); long long __ashrti3(long long a, int b); long long __ashlti3(long long a, int b); +#ifdef CONFIG_RISCV_ISA_V + +#ifdef CONFIG_MMU +asmlinkage int enter_vector_usercopy(void *dst, void *src, size_t n); +#endif /* CONFIG_MMU */ + +void xor_regs_2_(unsigned long bytes, unsigned long *__restrict p1, + const unsigned long *__restrict p2); +void xor_regs_3_(unsigned long bytes, unsigned long *__restrict p1, + const unsigned long *__restrict p2, + const unsigned long *__restrict p3); +void xor_regs_4_(unsigned long bytes, unsigned long *__restrict p1, + const unsigned long *__restrict p2, + const unsigned long *__restrict p3, + const unsigned long *__restrict p4); +void xor_regs_5_(unsigned long bytes, unsigned long *__restrict p1, + const unsigned long *__restrict p2, + const unsigned long *__restrict p3, + const unsigned long *__restrict p4, + const unsigned long *__restrict p5); + +#ifdef CONFIG_RISCV_ISA_V_PREEMPTIVE +asmlinkage void riscv_v_context_nesting_start(struct pt_regs *regs); +asmlinkage void riscv_v_context_nesting_end(struct pt_regs *regs); +#endif /* CONFIG_RISCV_ISA_V_PREEMPTIVE */ + +#endif /* CONFIG_RISCV_ISA_V */ #define DECLARE_DO_ERROR_INFO(name) asmlinkage void name(struct pt_regs *regs) diff --git a/arch/riscv/include/asm/entry-common.h b/arch/riscv/include/asm/entry-common.h index 7ab5e34318c8..2293e535f865 100644 --- a/arch/riscv/include/asm/entry-common.h +++ b/arch/riscv/include/asm/entry-common.h @@ -4,6 +4,23 @@ #define _ASM_RISCV_ENTRY_COMMON_H #include <asm/stacktrace.h> +#include <asm/thread_info.h> +#include <asm/vector.h> + +static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs, + unsigned long ti_work) +{ + if (ti_work & _TIF_RISCV_V_DEFER_RESTORE) { + clear_thread_flag(TIF_RISCV_V_DEFER_RESTORE); + /* + * We are already called with irq disabled, so go without + * keeping track of riscv_v_flags. + */ + riscv_v_vstate_restore(¤t->thread.vstate, regs); + } +} + +#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare void handle_page_fault(struct pt_regs *regs); void handle_break(struct pt_regs *regs); diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index e1944ff0757a..a8509cc31ab2 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -73,6 +73,43 @@ struct task_struct; struct pt_regs; +/* + * We use a flag to track in-kernel Vector context. Currently the flag has the + * following meaning: + * + * - bit 0: indicates whether the in-kernel Vector context is active. The + * activation of this state disables the preemption. On a non-RT kernel, it + * also disable bh. + * - bits 8: is used for tracking preemptible kernel-mode Vector, when + * RISCV_ISA_V_PREEMPTIVE is enabled. Calling kernel_vector_begin() does not + * disable the preemption if the thread's kernel_vstate.datap is allocated. + * Instead, the kernel set this bit field. Then the trap entry/exit code + * knows if we are entering/exiting the context that owns preempt_v. + * - 0: the task is not using preempt_v + * - 1: the task is actively using preempt_v. But whether does the task own + * the preempt_v context is decided by bits in RISCV_V_CTX_DEPTH_MASK. + * - bit 16-23 are RISCV_V_CTX_DEPTH_MASK, used by context tracking routine + * when preempt_v starts: + * - 0: the task is actively using, and own preempt_v context. + * - non-zero: the task was using preempt_v, but then took a trap within. + * Thus, the task does not own preempt_v. Any use of Vector will have to + * save preempt_v, if dirty, and fallback to non-preemptible kernel-mode + * Vector. + * - bit 30: The in-kernel preempt_v context is saved, and requries to be + * restored when returning to the context that owns the preempt_v. + * - bit 31: The in-kernel preempt_v context is dirty, as signaled by the + * trap entry code. Any context switches out-of current task need to save + * it to the task's in-kernel V context. Also, any traps nesting on-top-of + * preempt_v requesting to use V needs a save. + */ +#define RISCV_V_CTX_DEPTH_MASK 0x00ff0000 + +#define RISCV_V_CTX_UNIT_DEPTH 0x00010000 +#define RISCV_KERNEL_MODE_V 0x00000001 +#define RISCV_PREEMPT_V 0x00000100 +#define RISCV_PREEMPT_V_DIRTY 0x80000000 +#define RISCV_PREEMPT_V_NEED_RESTORE 0x40000000 + /* CPU-specific state of a task */ struct thread_struct { /* Callee-saved registers */ @@ -81,9 +118,11 @@ struct thread_struct { unsigned long s[12]; /* s[0]: frame pointer */ struct __riscv_d_ext_state fstate; unsigned long bad_cause; - unsigned long vstate_ctrl; + u32 riscv_v_flags; + u32 vstate_ctrl; struct __riscv_v_ext_state vstate; unsigned long align_ctl; + struct __riscv_v_ext_state kernel_vstate; }; /* Whitelist the fstate from the task_struct for hardened usercopy */ diff --git a/arch/riscv/include/asm/simd.h b/arch/riscv/include/asm/simd.h new file mode 100644 index 000000000000..54efbf523d49 --- /dev/null +++ b/arch/riscv/include/asm/simd.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org> + * Copyright (C) 2023 SiFive + */ + +#ifndef __ASM_SIMD_H +#define __ASM_SIMD_H + +#include <linux/compiler.h> +#include <linux/irqflags.h> +#include <linux/percpu.h> +#include <linux/preempt.h> +#include <linux/types.h> +#include <linux/thread_info.h> + +#include <asm/vector.h> + +#ifdef CONFIG_RISCV_ISA_V +/* + * may_use_simd - whether it is allowable at this time to issue vector + * instructions or access the vector register file + * + * Callers must not assume that the result remains true beyond the next + * preempt_enable() or return from softirq context. + */ +static __must_check inline bool may_use_simd(void) +{ + /* + * RISCV_KERNEL_MODE_V is only set while preemption is disabled, + * and is clear whenever preemption is enabled. + */ + if (in_hardirq() || in_nmi()) + return false; + + /* + * Nesting is acheived in preempt_v by spreading the control for + * preemptible and non-preemptible kernel-mode Vector into two fields. + * Always try to match with prempt_v if kernel V-context exists. Then, + * fallback to check non preempt_v if nesting happens, or if the config + * is not set. + */ + if (IS_ENABLED(CONFIG_RISCV_ISA_V_PREEMPTIVE) && current->thread.kernel_vstate.datap) { + if (!riscv_preempt_v_started(current)) + return true; + } + /* + * Non-preemptible kernel-mode Vector temporarily disables bh. So we + * must not return true on irq_disabled(). Otherwise we would fail the + * lockdep check calling local_bh_enable() + */ + return !irqs_disabled() && !(riscv_v_flags() & RISCV_KERNEL_MODE_V); +} + +#else /* ! CONFIG_RISCV_ISA_V */ + +static __must_check inline bool may_use_simd(void) +{ + return false; +} + +#endif /* ! CONFIG_RISCV_ISA_V */ + +#endif diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h index f90d8e42f3c7..7efdb0584d47 100644 --- a/arch/riscv/include/asm/switch_to.h +++ b/arch/riscv/include/asm/switch_to.h @@ -53,8 +53,7 @@ static inline void __switch_to_fpu(struct task_struct *prev, struct pt_regs *regs; regs = task_pt_regs(prev); - if (unlikely(regs->status & SR_SD)) - fstate_save(prev, regs); + fstate_save(prev, regs); fstate_restore(next, task_pt_regs(next)); } diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h index 4856697c5f25..5d473343634b 100644 --- a/arch/riscv/include/asm/thread_info.h +++ b/arch/riscv/include/asm/thread_info.h @@ -102,12 +102,14 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); #define TIF_NOTIFY_SIGNAL 9 /* signal notifications exist */ #define TIF_UPROBE 10 /* uprobe breakpoint or singlestep */ #define TIF_32BIT 11 /* compat-mode 32bit process */ +#define TIF_RISCV_V_DEFER_RESTORE 12 /* restore Vector before returing to user */ #define _TIF_NOTIFY_RESUME (1 << TIF_NOTIFY_RESUME) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) #define _TIF_NOTIFY_SIGNAL (1 << TIF_NOTIFY_SIGNAL) #define _TIF_UPROBE (1 << TIF_UPROBE) +#define _TIF_RISCV_V_DEFER_RESTORE (1 << TIF_RISCV_V_DEFER_RESTORE) #define _TIF_WORK_MASK \ (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED | \ diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index 87aaef656257..0cd6f0a027d1 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -22,6 +22,18 @@ extern unsigned long riscv_v_vsize; int riscv_v_setup_vsize(void); bool riscv_v_first_use_handler(struct pt_regs *regs); +void kernel_vector_begin(void); +void kernel_vector_end(void); +void get_cpu_vector_context(void); +void put_cpu_vector_context(void); +void riscv_v_thread_free(struct task_struct *tsk); +void __init riscv_v_setup_ctx_cache(void); +void riscv_v_thread_alloc(struct task_struct *tsk); + +static inline u32 riscv_v_flags(void) +{ + return READ_ONCE(current->thread.riscv_v_flags); +} static __always_inline bool has_vector(void) { @@ -162,36 +174,89 @@ static inline void riscv_v_vstate_discard(struct pt_regs *regs) __riscv_v_vstate_dirty(regs); } -static inline void riscv_v_vstate_save(struct task_struct *task, +static inline void riscv_v_vstate_save(struct __riscv_v_ext_state *vstate, struct pt_regs *regs) { if ((regs->status & SR_VS) == SR_VS_DIRTY) { - struct __riscv_v_ext_state *vstate = &task->thread.vstate; - __riscv_v_vstate_save(vstate, vstate->datap); __riscv_v_vstate_clean(regs); } } -static inline void riscv_v_vstate_restore(struct task_struct *task, +static inline void riscv_v_vstate_restore(struct __riscv_v_ext_state *vstate, struct pt_regs *regs) { if ((regs->status & SR_VS) != SR_VS_OFF) { - struct __riscv_v_ext_state *vstate = &task->thread.vstate; - __riscv_v_vstate_restore(vstate, vstate->datap); __riscv_v_vstate_clean(regs); } } +static inline void riscv_v_vstate_set_restore(struct task_struct *task, + struct pt_regs *regs) +{ + if ((regs->status & SR_VS) != SR_VS_OFF) { + set_tsk_thread_flag(task, TIF_RISCV_V_DEFER_RESTORE); + riscv_v_vstate_on(regs); + } +} + +#ifdef CONFIG_RISCV_ISA_V_PREEMPTIVE +static inline bool riscv_preempt_v_dirty(struct task_struct *task) +{ + return !!(task->thread.riscv_v_flags & RISCV_PREEMPT_V_DIRTY); +} + +static inline bool riscv_preempt_v_restore(struct task_struct *task) +{ + return !!(task->thread.riscv_v_flags & RISCV_PREEMPT_V_NEED_RESTORE); +} + +static inline void riscv_preempt_v_clear_dirty(struct task_struct *task) +{ + barrier(); + task->thread.riscv_v_flags &= ~RISCV_PREEMPT_V_DIRTY; +} + +static inline void riscv_preempt_v_set_restore(struct task_struct *task) +{ + barrier(); + task->thread.riscv_v_flags |= RISCV_PREEMPT_V_NEED_RESTORE; +} + +static inline bool riscv_preempt_v_started(struct task_struct *task) +{ + return !!(task->thread.riscv_v_flags & RISCV_PREEMPT_V); +} + +#else /* !CONFIG_RISCV_ISA_V_PREEMPTIVE */ +static inline bool riscv_preempt_v_dirty(struct task_struct *task) { return false; } +static inline bool riscv_preempt_v_restore(struct task_struct *task) { return false; } +static inline bool riscv_preempt_v_started(struct task_struct *task) { return false; } +#define riscv_preempt_v_clear_dirty(tsk) do {} while (0) +#define riscv_preempt_v_set_restore(tsk) do {} while (0) +#endif /* CONFIG_RISCV_ISA_V_PREEMPTIVE */ + static inline void __switch_to_vector(struct task_struct *prev, struct task_struct *next) { struct pt_regs *regs; - regs = task_pt_regs(prev); - riscv_v_vstate_save(prev, regs); - riscv_v_vstate_restore(next, task_pt_regs(next)); + if (riscv_preempt_v_started(prev)) { + if (riscv_preempt_v_dirty(prev)) { + __riscv_v_vstate_save(&prev->thread.kernel_vstate, + prev->thread.kernel_vstate.datap); + riscv_preempt_v_clear_dirty(prev); + } + } else { + regs = task_pt_regs(prev); + riscv_v_vstate_save(&prev->thread.vstate, regs); + } + + if (riscv_preempt_v_started(next)) + riscv_preempt_v_set_restore(next); + else + riscv_v_vstate_set_restore(next, task_pt_regs(next)); } void riscv_v_vstate_ctrl_init(struct task_struct *tsk); @@ -208,11 +273,14 @@ static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; } static inline bool riscv_v_vstate_ctrl_user_allowed(void) { return false; } #define riscv_v_vsize (0) #define riscv_v_vstate_discard(regs) do {} while (0) -#define riscv_v_vstate_save(task, regs) do {} while (0) -#define riscv_v_vstate_restore(task, regs) do {} while (0) +#define riscv_v_vstate_save(vstate, regs) do {} while (0) +#define riscv_v_vstate_restore(vstate, regs) do {} while (0) #define __switch_to_vector(__prev, __next) do {} while (0) #define riscv_v_vstate_off(regs) do {} while (0) #define riscv_v_vstate_on(regs) do {} while (0) +#define riscv_v_thread_free(tsk) do {} while (0) +#define riscv_v_setup_ctx_cache() do {} while (0) +#define riscv_v_thread_alloc(tsk) do {} while (0) #endif /* CONFIG_RISCV_ISA_V */ diff --git a/arch/riscv/include/asm/xor.h b/arch/riscv/include/asm/xor.h new file mode 100644 index 000000000000..96011861e46b --- /dev/null +++ b/arch/riscv/include/asm/xor.h @@ -0,0 +1,68 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2021 SiFive + */ + +#include <linux/hardirq.h> +#include <asm-generic/xor.h> +#ifdef CONFIG_RISCV_ISA_V +#include <asm/vector.h> +#include <asm/switch_to.h> +#include <asm/asm-prototypes.h> + +static void xor_vector_2(unsigned long bytes, unsigned long *__restrict p1, + const unsigned long *__restrict p2) +{ + kernel_vector_begin(); + xor_regs_2_(bytes, p1, p2); + kernel_vector_end(); +} + +static void xor_vector_3(unsigned long bytes, unsigned long *__restrict p1, + const unsigned long *__restrict p2, + const unsigned long *__restrict p3) +{ + kernel_vector_begin(); + xor_regs_3_(bytes, p1, p2, p3); + kernel_vector_end(); +} + +static void xor_vector_4(unsigned long bytes, unsigned long *__restrict p1, + const unsigned long *__restrict p2, + const unsigned long *__restrict p3, + const unsigned long *__restrict p4) +{ + kernel_vector_begin(); + xor_regs_4_(bytes, p1, p2, p3, p4); + kernel_vector_end(); +} + +static void xor_vector_5(unsigned long bytes, unsigned long *__restrict p1, + const unsigned long *__restrict p2, + const unsigned long *__restrict p3, + const unsigned long *__restrict p4, + const unsigned long *__restrict p5) +{ + kernel_vector_begin(); + xor_regs_5_(bytes, p1, p2, p3, p4, p5); + kernel_vector_end(); +} + +static struct xor_block_template xor_block_rvv = { + .name = "rvv", + .do_2 = xor_vector_2, + .do_3 = xor_vector_3, + .do_4 = xor_vector_4, + .do_5 = xor_vector_5 +}; + +#undef XOR_TRY_TEMPLATES +#define XOR_TRY_TEMPLATES \ + do { \ + xor_speed(&xor_block_8regs); \ + xor_speed(&xor_block_32regs); \ + if (has_vector()) { \ + xor_speed(&xor_block_rvv);\ + } \ + } while (0) +#endif |