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Diffstat (limited to 'arch/riscv/include/asm/vector.h')
| -rw-r--r-- | arch/riscv/include/asm/vector.h | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h new file mode 100644 index 000000000000..731dcd0ed4de --- /dev/null +++ b/arch/riscv/include/asm/vector.h @@ -0,0 +1,298 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2020 SiFive + */ + +#ifndef __ASM_RISCV_VECTOR_H +#define __ASM_RISCV_VECTOR_H + +#include <linux/types.h> +#include <uapi/asm-generic/errno.h> + +#ifdef CONFIG_RISCV_ISA_V + +#include <linux/stringify.h> +#include <linux/sched.h> +#include <linux/sched/task_stack.h> +#include <asm/ptrace.h> +#include <asm/cpufeature.h> +#include <asm/csr.h> +#include <asm/asm.h> + +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) +{ + return riscv_has_extension_unlikely(RISCV_ISA_EXT_v); +} + +static inline void __riscv_v_vstate_clean(struct pt_regs *regs) +{ + regs->status = (regs->status & ~SR_VS) | SR_VS_CLEAN; +} + +static inline void __riscv_v_vstate_dirty(struct pt_regs *regs) +{ + regs->status = (regs->status & ~SR_VS) | SR_VS_DIRTY; +} + +static inline void riscv_v_vstate_off(struct pt_regs *regs) +{ + regs->status = (regs->status & ~SR_VS) | SR_VS_OFF; +} + +static inline void riscv_v_vstate_on(struct pt_regs *regs) +{ + regs->status = (regs->status & ~SR_VS) | SR_VS_INITIAL; +} + +static inline bool riscv_v_vstate_query(struct pt_regs *regs) +{ + return (regs->status & SR_VS) != 0; +} + +static __always_inline void riscv_v_enable(void) +{ + csr_set(CSR_SSTATUS, SR_VS); +} + +static __always_inline void riscv_v_disable(void) +{ + csr_clear(CSR_SSTATUS, SR_VS); +} + +static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest) +{ + asm volatile ( + "csrr %0, " __stringify(CSR_VSTART) "\n\t" + "csrr %1, " __stringify(CSR_VTYPE) "\n\t" + "csrr %2, " __stringify(CSR_VL) "\n\t" + "csrr %3, " __stringify(CSR_VCSR) "\n\t" + "csrr %4, " __stringify(CSR_VLENB) "\n\t" + : "=r" (dest->vstart), "=r" (dest->vtype), "=r" (dest->vl), + "=r" (dest->vcsr), "=r" (dest->vlenb) : :); +} + +static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src) +{ + asm volatile ( + ".option push\n\t" + ".option arch, +v\n\t" + "vsetvl x0, %2, %1\n\t" + ".option pop\n\t" + "csrw " __stringify(CSR_VSTART) ", %0\n\t" + "csrw " __stringify(CSR_VCSR) ", %3\n\t" + : : "r" (src->vstart), "r" (src->vtype), "r" (src->vl), + "r" (src->vcsr) :); +} + +static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to, + void *datap) +{ + unsigned long vl; + + riscv_v_enable(); + __vstate_csr_save(save_to); + asm volatile ( + ".option push\n\t" + ".option arch, +v\n\t" + "vsetvli %0, x0, e8, m8, ta, ma\n\t" + "vse8.v v0, (%1)\n\t" + "add %1, %1, %0\n\t" + "vse8.v v8, (%1)\n\t" + "add %1, %1, %0\n\t" + "vse8.v v16, (%1)\n\t" + "add %1, %1, %0\n\t" + "vse8.v v24, (%1)\n\t" + ".option pop\n\t" + : "=&r" (vl) : "r" (datap) : "memory"); + riscv_v_disable(); +} + +static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_from, + void *datap) +{ + unsigned long vl; + + riscv_v_enable(); + asm volatile ( + ".option push\n\t" + ".option arch, +v\n\t" + "vsetvli %0, x0, e8, m8, ta, ma\n\t" + "vle8.v v0, (%1)\n\t" + "add %1, %1, %0\n\t" + "vle8.v v8, (%1)\n\t" + "add %1, %1, %0\n\t" + "vle8.v v16, (%1)\n\t" + "add %1, %1, %0\n\t" + "vle8.v v24, (%1)\n\t" + ".option pop\n\t" + : "=&r" (vl) : "r" (datap) : "memory"); + __vstate_csr_restore(restore_from); + riscv_v_disable(); +} + +static inline void __riscv_v_vstate_discard(void) +{ + unsigned long vl, vtype_inval = 1UL << (BITS_PER_LONG - 1); + + riscv_v_enable(); + asm volatile ( + ".option push\n\t" + ".option arch, +v\n\t" + "vsetvli %0, x0, e8, m8, ta, ma\n\t" + "vmv.v.i v0, -1\n\t" + "vmv.v.i v8, -1\n\t" + "vmv.v.i v16, -1\n\t" + "vmv.v.i v24, -1\n\t" + "vsetvl %0, x0, %1\n\t" + ".option pop\n\t" + : "=&r" (vl) : "r" (vtype_inval) : "memory"); + riscv_v_disable(); +} + +static inline void riscv_v_vstate_discard(struct pt_regs *regs) +{ + if ((regs->status & SR_VS) == SR_VS_OFF) + return; + + __riscv_v_vstate_discard(); + __riscv_v_vstate_dirty(regs); +} + +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) { + __riscv_v_vstate_save(vstate, vstate->datap); + __riscv_v_vstate_clean(regs); + } +} + +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) { + __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; + + 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); +bool riscv_v_vstate_ctrl_user_allowed(void); + +#else /* ! CONFIG_RISCV_ISA_V */ + +struct pt_regs; + +static inline int riscv_v_setup_vsize(void) { return -EOPNOTSUPP; } +static __always_inline bool has_vector(void) { return false; } +static inline bool riscv_v_first_use_handler(struct pt_regs *regs) { return false; } +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(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 */ + +/* + * Return the implementation's vlen value. + * + * riscv_v_vsize contains the value of "32 vector registers with vlenb length" + * so rebuild the vlen value in bits from it. + */ +static inline int riscv_vector_vlen(void) +{ + return riscv_v_vsize / 32 * 8; +} + +#endif /* ! __ASM_RISCV_VECTOR_H */ |