Hi Charlie,
A couple of suggestions for simplification below.
On 2024-06-19 6:57 PM, Charlie Jenkins wrote:
> Use alternatives to add support for xtheadvector vector save/restore
> routines.
>
> Signed-off-by: Charlie Jenkins <charlie@xxxxxxxxxxxx>
> Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> ---
> arch/riscv/include/asm/csr.h | 6 +
> arch/riscv/include/asm/switch_to.h | 2 +-
> arch/riscv/include/asm/vector.h | 249 ++++++++++++++++++++++++++-------
> arch/riscv/kernel/cpufeature.c | 2 +-
> arch/riscv/kernel/kernel_mode_vector.c | 8 +-
> arch/riscv/kernel/process.c | 4 +-
> arch/riscv/kernel/signal.c | 6 +-
> arch/riscv/kernel/vector.c | 13 +-
> 8 files changed, 222 insertions(+), 68 deletions(-)
>
> diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
> index 9086639a3dde..407d4a5687f5 100644
> --- a/arch/riscv/include/asm/csr.h
> +++ b/arch/riscv/include/asm/csr.h
> @@ -30,6 +30,12 @@
> #define SR_VS_CLEAN _AC(0x00000400, UL)
> #define SR_VS_DIRTY _AC(0x00000600, UL)
>
> +#define SR_VS_THEAD _AC(0x01800000, UL) /* xtheadvector Status */
> +#define SR_VS_OFF_THEAD _AC(0x00000000, UL)
> +#define SR_VS_INITIAL_THEAD _AC(0x00800000, UL)
> +#define SR_VS_CLEAN_THEAD _AC(0x01000000, UL)
> +#define SR_VS_DIRTY_THEAD _AC(0x01800000, UL)
> +
> #define SR_XS _AC(0x00018000, UL) /* Extension Status */
> #define SR_XS_OFF _AC(0x00000000, UL)
> #define SR_XS_INITIAL _AC(0x00008000, UL)
> diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h
> index 7594df37cc9f..f9cbebe372b8 100644
> --- a/arch/riscv/include/asm/switch_to.h
> +++ b/arch/riscv/include/asm/switch_to.h
> @@ -99,7 +99,7 @@ do { \
> __set_prev_cpu(__prev->thread); \
> if (has_fpu()) \
> __switch_to_fpu(__prev, __next); \
> - if (has_vector()) \
> + if (has_vector() || has_xtheadvector()) \
> __switch_to_vector(__prev, __next); \
> if (switch_to_should_flush_icache(__next)) \
> local_flush_icache_all(); \
> diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h
> index 731dcd0ed4de..6294dcaabc6a 100644
> --- a/arch/riscv/include/asm/vector.h
> +++ b/arch/riscv/include/asm/vector.h
> @@ -18,6 +18,27 @@
> #include <asm/cpufeature.h>
> #include <asm/csr.h>
> #include <asm/asm.h>
> +#include <asm/vendorid_list.h>
> +#include <asm/vendor_extensions.h>
> +#include <asm/vendor_extensions/thead.h>
> +
> +#define __riscv_v_vstate_or(_val, TYPE) ({ \
> + typeof(_val) _res = _val; \
> + if (has_xtheadvector()) \
> + _res = (_res & ~SR_VS_THEAD) | SR_VS_##TYPE##_THEAD; \
> + else \
> + _res = (_res & ~SR_VS) | SR_VS_##TYPE; \
> + _res; \
> +})
> +
> +#define __riscv_v_vstate_check(_val, TYPE) ({ \
> + bool _res; \
> + if (has_xtheadvector()) \
> + _res = ((_val) & SR_VS_THEAD) == SR_VS_##TYPE##_THEAD; \
> + else \
> + _res = ((_val) & SR_VS) == SR_VS_##TYPE; \
> + _res; \
> +})
>
> extern unsigned long riscv_v_vsize;
> int riscv_v_setup_vsize(void);
> @@ -40,39 +61,62 @@ static __always_inline bool has_vector(void)
> return riscv_has_extension_unlikely(RISCV_ISA_EXT_v);
> }
>
> +static __always_inline bool has_xtheadvector_no_alternatives(void)
> +{
> + if (IS_ENABLED(CONFIG_RISCV_ISA_XTHEADVECTOR))
> + return riscv_isa_vendor_extension_available(THEAD_VENDOR_ID, XTHEADVECTOR);
> + else
> + return false;
> +}
> +
> +static __always_inline bool has_xtheadvector(void)
> +{
> + if (IS_ENABLED(CONFIG_RISCV_ISA_XTHEADVECTOR))
> + return riscv_has_vendor_extension_unlikely(THEAD_VENDOR_ID,
> + RISCV_ISA_VENDOR_EXT_XTHEADVECTOR);
> + else
> + return false;
> +}
> +
> static inline void __riscv_v_vstate_clean(struct pt_regs *regs)
> {
> - regs->status = (regs->status & ~SR_VS) | SR_VS_CLEAN;
> + regs->status = __riscv_v_vstate_or(regs->status, CLEAN);
> }
>
> static inline void __riscv_v_vstate_dirty(struct pt_regs *regs)
> {
> - regs->status = (regs->status & ~SR_VS) | SR_VS_DIRTY;
> + regs->status = __riscv_v_vstate_or(regs->status, DIRTY);
> }
>
> static inline void riscv_v_vstate_off(struct pt_regs *regs)
> {
> - regs->status = (regs->status & ~SR_VS) | SR_VS_OFF;
> + regs->status = __riscv_v_vstate_or(regs->status, OFF);
> }
>
> static inline void riscv_v_vstate_on(struct pt_regs *regs)
> {
> - regs->status = (regs->status & ~SR_VS) | SR_VS_INITIAL;
> + regs->status = __riscv_v_vstate_or(regs->status, INITIAL);
> }
>
> static inline bool riscv_v_vstate_query(struct pt_regs *regs)
> {
> - return (regs->status & SR_VS) != 0;
> + return !__riscv_v_vstate_check(regs->status, OFF);
> }
>
> static __always_inline void riscv_v_enable(void)
> {
> - csr_set(CSR_SSTATUS, SR_VS);
> + if (has_xtheadvector())
> + csr_set(CSR_SSTATUS, SR_VS_THEAD);
> + else
> + csr_set(CSR_SSTATUS, SR_VS);
> }
>
> static __always_inline void riscv_v_disable(void)
> {
> - csr_clear(CSR_SSTATUS, SR_VS);
> + if (has_xtheadvector())
> + csr_clear(CSR_SSTATUS, SR_VS_THEAD);
> + else
> + csr_clear(CSR_SSTATUS, SR_VS);
> }
>
> static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest)
> @@ -81,10 +125,49 @@ static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest)
> "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) : :);
> + "=r" (dest->vcsr) : :);
> +
> + if (has_xtheadvector()) {
> + u32 tmp_vcsr;
> + bool restore_fpu = false;
> + unsigned long status = csr_read(CSR_SSTATUS);
> +
> + /*
> + * CSR_VCSR is defined as
> + * [2:1] - vxrm[1:0]
> + * [0] - vxsat
> + * The earlier vector spec implemented by T-Head uses separate
> + * registers for the same bit-elements, so just combine those
> + * into the existing output field.
> + *
> + * Additionally T-Head cores need FS to be enabled when accessing
> + * the VXRM and VXSAT CSRs, otherwise ending in illegal instructions.
> + * Though the cores do not implement the VXRM and VXSAT fields in the
> + * FCSR CSR that vector-0.7.1 specifies.
> + */
> + if ((status & SR_FS) == SR_FS_OFF) {
> + csr_set(CSR_SSTATUS, (status & ~SR_FS) | SR_FS_CLEAN);
> + restore_fpu = true;
> + }
This simplifies to:
unsigned long status = csr_read_set(CSR_STATUS, SR_FS_DIRTY);
and then below:
if ((status & SR_FS) != SR_FS_DIRTY)
csr_write(CSR_STATUS, status);
> +
> + asm volatile (
> + "csrr %[tmp_vcsr], " __stringify(VCSR_VXRM) "\n\t"
> + "slliw %[vcsr], %[tmp_vcsr], " __stringify(VCSR_VXRM_SHIFT) "\n\t"
> + "csrr %[tmp_vcsr], " __stringify(VCSR_VXSAT) "\n\t"
> + "or %[vcsr], %[vcsr], %[tmp_vcsr]\n\t"
> + : [vcsr] "=r" (dest->vcsr), [tmp_vcsr] "=&r" (tmp_vcsr));
None of this needs to be inline assembly. I think the only reason that
__vstate_csr_save() uses inline assembly is to match __vstate_csr_restore(),
which needs it to execute a vsetvl instruction. This would be easier to parse if
it used csr_read().
> +
> + dest->vlenb = riscv_v_vsize / 32;
This value can't change at runtime (for either standard V or Xtheadvector), so
we don't need to save it every time. So (possibly as a future optimization) this
could be saved only once when the context is first initialized.
> +
> + if (restore_fpu)
> + csr_set(CSR_SSTATUS, status);
> + } else {
> + asm volatile (
> + "csrr %[vcsr], " __stringify(CSR_VCSR) "\n\t"
> + "csrr %[vlenb], " __stringify(CSR_VLENB) "\n\t"
> + : [vcsr] "=r" (dest->vcsr), [vlenb] "=r" (dest->vlenb));
> + }
> }
>
> static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src)
> @@ -95,9 +178,37 @@ static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src
> "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) :);
> + : : "r" (src->vstart), "r" (src->vtype), "r" (src->vl));
> +
> + if (has_xtheadvector()) {
> + u32 tmp_vcsr;
> + bool restore_fpu = false;
> + unsigned long status = csr_read(CSR_SSTATUS);
> +
> + /*
> + * Similar to __vstate_csr_save above, restore values for the
> + * separate VXRM and VXSAT CSRs from the vcsr variable.
> + */
> + if ((status & SR_FS) == SR_FS_OFF) {
> + csr_set(CSR_SSTATUS, (status & ~SR_FS) | SR_FS_CLEAN);
> + restore_fpu = true;
> + }
> +
> + asm volatile (
> + "srliw %[tmp_vcsr], %[vcsr], " __stringify(VCSR_VXRM_SHIFT) "\n\t"
> + "andi %[tmp_vcsr], %[tmp_vcsr], " __stringify(VCSR_VXRM_MASK) "\n\t"
> + "csrw " __stringify(VCSR_VXRM) ", %[tmp_vcsr]\n\t"
> + "andi %[tmp_vcsr], %[vcsr], " __stringify(VCSR_VXSAT_MASK) "\n\t"
> + "csrw " __stringify(VCSR_VXSAT) ", %[tmp_vcsr]\n\t"
> + : [tmp_vcsr] "=&r" (tmp_vcsr) : [vcsr] "r" (src->vcsr));
Similarly, this would be a lot easier to parse with csr_write() instead of
inline assembly.
Regards,
Samuel
> +
> + if (restore_fpu)
> + csr_set(CSR_SSTATUS, status);
> + } else {
> + asm volatile (
> + "csrw " __stringify(CSR_VCSR) ", %[vcsr]\n\t"
> + : : [vcsr] "r" (src->vcsr));
> + }
> }
>
> static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to,
> @@ -107,19 +218,33 @@ static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to,
>
> 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");
> + if (has_xtheadvector()) {
> + asm volatile (
> + "mv t0, %0\n\t"
> + THEAD_VSETVLI_T4X0E8M8D1
> + THEAD_VSB_V_V0T0
> + "add t0, t0, t4\n\t"
> + THEAD_VSB_V_V0T0
> + "add t0, t0, t4\n\t"
> + THEAD_VSB_V_V0T0
> + "add t0, t0, t4\n\t"
> + THEAD_VSB_V_V0T0
> + : : "r" (datap) : "memory", "t0", "t4");
> + } else {
> + 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();
> }
>
> @@ -129,55 +254,77 @@ static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_
> 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");
> + if (has_xtheadvector()) {
> + asm volatile (
> + "mv t0, %0\n\t"
> + THEAD_VSETVLI_T4X0E8M8D1
> + THEAD_VLB_V_V0T0
> + "add t0, t0, t4\n\t"
> + THEAD_VLB_V_V0T0
> + "add t0, t0, t4\n\t"
> + THEAD_VLB_V_V0T0
> + "add t0, t0, t4\n\t"
> + THEAD_VLB_V_V0T0
> + : : "r" (datap) : "memory", "t0", "t4");
> + } else {
> + 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);
> + unsigned long vtype_inval = 1UL << (BITS_PER_LONG - 1);
>
> riscv_v_enable();
> + if (has_xtheadvector())
> + asm volatile (THEAD_VSETVLI_X0X0E8M8D1);
> + else
> + asm volatile (
> + ".option push\n\t"
> + ".option arch, +v\n\t"
> + "vsetvli x0, x0, e8, m8, ta, ma\n\t"
> + ".option pop\n\t");
> +
> 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"
> + "vsetvl x0, x0, %0\n\t"
> ".option pop\n\t"
> - : "=&r" (vl) : "r" (vtype_inval) : "memory");
> + : : "r" (vtype_inval));
> +
> 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);
> + if (riscv_v_vstate_query(regs)) {
> + __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) {
> + if (__riscv_v_vstate_check(regs->status, DIRTY)) {
> __riscv_v_vstate_save(vstate, vstate->datap);
> __riscv_v_vstate_clean(regs);
> }
> @@ -186,7 +333,7 @@ static inline void riscv_v_vstate_save(struct __riscv_v_ext_state *vstate,
> 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) {
> + if (riscv_v_vstate_query(regs)) {
> __riscv_v_vstate_restore(vstate, vstate->datap);
> __riscv_v_vstate_clean(regs);
> }
> @@ -195,7 +342,7 @@ static inline void riscv_v_vstate_restore(struct __riscv_v_ext_state *vstate,
> static inline void riscv_v_vstate_set_restore(struct task_struct *task,
> struct pt_regs *regs)
> {
> - if ((regs->status & SR_VS) != SR_VS_OFF) {
> + if (riscv_v_vstate_query(regs)) {
> set_tsk_thread_flag(task, TIF_RISCV_V_DEFER_RESTORE);
> riscv_v_vstate_on(regs);
> }
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 077be4ab1f9a..180f7eae9086 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -789,7 +789,7 @@ void __init riscv_fill_hwcap(void)
> elf_hwcap &= ~COMPAT_HWCAP_ISA_F;
> }
>
> - if (elf_hwcap & COMPAT_HWCAP_ISA_V) {
> + if (elf_hwcap & COMPAT_HWCAP_ISA_V || has_xtheadvector_no_alternatives()) {
> riscv_v_setup_vsize();
> /*
> * ISA string in device tree might have 'v' flag, but
> diff --git a/arch/riscv/kernel/kernel_mode_vector.c b/arch/riscv/kernel/kernel_mode_vector.c
> index 6afe80c7f03a..99972a48e86b 100644
> --- a/arch/riscv/kernel/kernel_mode_vector.c
> +++ b/arch/riscv/kernel/kernel_mode_vector.c
> @@ -143,7 +143,7 @@ static int riscv_v_start_kernel_context(bool *is_nested)
>
> /* Transfer the ownership of V from user to kernel, then save */
> riscv_v_start(RISCV_PREEMPT_V | RISCV_PREEMPT_V_DIRTY);
> - if ((task_pt_regs(current)->status & SR_VS) == SR_VS_DIRTY) {
> + if (__riscv_v_vstate_check(task_pt_regs(current)->status, DIRTY)) {
> uvstate = ¤t->thread.vstate;
> __riscv_v_vstate_save(uvstate, uvstate->datap);
> }
> @@ -160,7 +160,7 @@ asmlinkage void riscv_v_context_nesting_start(struct pt_regs *regs)
> return;
>
> depth = riscv_v_ctx_get_depth();
> - if (depth == 0 && (regs->status & SR_VS) == SR_VS_DIRTY)
> + if (depth == 0 && __riscv_v_vstate_check(regs->status, DIRTY))
> riscv_preempt_v_set_dirty();
>
> riscv_v_ctx_depth_inc();
> @@ -208,7 +208,7 @@ void kernel_vector_begin(void)
> {
> bool nested = false;
>
> - if (WARN_ON(!has_vector()))
> + if (WARN_ON(!(has_vector() || has_xtheadvector())))
> return;
>
> BUG_ON(!may_use_simd());
> @@ -236,7 +236,7 @@ EXPORT_SYMBOL_GPL(kernel_vector_begin);
> */
> void kernel_vector_end(void)
> {
> - if (WARN_ON(!has_vector()))
> + if (WARN_ON(!(has_vector() || has_xtheadvector())))
> return;
>
> riscv_v_disable();
> diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
> index e4bc61c4e58a..191023decd16 100644
> --- a/arch/riscv/kernel/process.c
> +++ b/arch/riscv/kernel/process.c
> @@ -176,7 +176,7 @@ void flush_thread(void)
> void arch_release_task_struct(struct task_struct *tsk)
> {
> /* Free the vector context of datap. */
> - if (has_vector())
> + if (has_vector() || has_xtheadvector())
> riscv_v_thread_free(tsk);
> }
>
> @@ -222,7 +222,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
> p->thread.s[0] = 0;
> }
> p->thread.riscv_v_flags = 0;
> - if (has_vector())
> + if (has_vector() || has_xtheadvector())
> riscv_v_thread_alloc(p);
> p->thread.ra = (unsigned long)ret_from_fork;
> p->thread.sp = (unsigned long)childregs; /* kernel sp */
> diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
> index 5a2edd7f027e..1d5e4b3ca9e1 100644
> --- a/arch/riscv/kernel/signal.c
> +++ b/arch/riscv/kernel/signal.c
> @@ -189,7 +189,7 @@ static long restore_sigcontext(struct pt_regs *regs,
>
> return 0;
> case RISCV_V_MAGIC:
> - if (!has_vector() || !riscv_v_vstate_query(regs) ||
> + if (!(has_vector() || has_xtheadvector()) || !riscv_v_vstate_query(regs) ||
> size != riscv_v_sc_size)
> return -EINVAL;
>
> @@ -211,7 +211,7 @@ static size_t get_rt_frame_size(bool cal_all)
>
> frame_size = sizeof(*frame);
>
> - if (has_vector()) {
> + if (has_vector() || has_xtheadvector()) {
> if (cal_all || riscv_v_vstate_query(task_pt_regs(current)))
> total_context_size += riscv_v_sc_size;
> }
> @@ -284,7 +284,7 @@ static long setup_sigcontext(struct rt_sigframe __user *frame,
> if (has_fpu())
> err |= save_fp_state(regs, &sc->sc_fpregs);
> /* Save the vector state. */
> - if (has_vector() && riscv_v_vstate_query(regs))
> + if ((has_vector() || has_xtheadvector()) && riscv_v_vstate_query(regs))
> err |= save_v_state(regs, (void __user **)&sc_ext_ptr);
> /* Write zero to fp-reserved space and check it on restore_sigcontext */
> err |= __put_user(0, &sc->sc_extdesc.reserved);
> diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c
> index 3ba2f2432483..83126995f61a 100644
> --- a/arch/riscv/kernel/vector.c
> +++ b/arch/riscv/kernel/vector.c
> @@ -63,7 +63,7 @@ int riscv_v_setup_vsize(void)
>
> void __init riscv_v_setup_ctx_cache(void)
> {
> - if (!has_vector())
> + if (!(has_vector() || has_xtheadvector()))
> return;
>
> riscv_v_user_cachep = kmem_cache_create_usercopy("riscv_vector_ctx",
> @@ -184,7 +184,8 @@ bool riscv_v_first_use_handler(struct pt_regs *regs)
> u32 insn = (u32)regs->badaddr;
>
> /* Do not handle if V is not supported, or disabled */
> - if (!(ELF_HWCAP & COMPAT_HWCAP_ISA_V))
> + if (!(ELF_HWCAP & COMPAT_HWCAP_ISA_V) &&
> + !(has_xtheadvector() && riscv_v_vstate_ctrl_user_allowed()))
> return false;
>
> /* If V has been enabled then it is not the first-use trap */
> @@ -223,7 +224,7 @@ void riscv_v_vstate_ctrl_init(struct task_struct *tsk)
> bool inherit;
> int cur, next;
>
> - if (!has_vector())
> + if (!(has_vector() || has_xtheadvector()))
> return;
>
> next = riscv_v_ctrl_get_next(tsk);
> @@ -245,7 +246,7 @@ void riscv_v_vstate_ctrl_init(struct task_struct *tsk)
>
> long riscv_v_vstate_ctrl_get_current(void)
> {
> - if (!has_vector())
> + if (!(has_vector() || has_xtheadvector()))
> return -EINVAL;
>
> return current->thread.vstate_ctrl & PR_RISCV_V_VSTATE_CTRL_MASK;
> @@ -256,7 +257,7 @@ long riscv_v_vstate_ctrl_set_current(unsigned long arg)
> bool inherit;
> int cur, next;
>
> - if (!has_vector())
> + if (!(has_vector() || has_xtheadvector()))
> return -EINVAL;
>
> if (arg & ~PR_RISCV_V_VSTATE_CTRL_MASK)
> @@ -306,7 +307,7 @@ static struct ctl_table riscv_v_default_vstate_table[] = {
>
> static int __init riscv_v_sysctl_init(void)
> {
> - if (has_vector())
> + if (has_vector() || has_xtheadvector())
> if (!register_sysctl("abi", riscv_v_default_vstate_table))
> return -EINVAL;
> return 0;
>
