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 <[email protected]> Acked-by: Joel Granados <[email protected]> --- Changelog v5: - Remove the paramerter from has_vector()'s prototype. Instead, make it check for ZVE32X only. Everything else should make additional alternative checks. (Conor) Changelog v4: - check static_assert for !CONFIG_RISCV_ISA_V case in has_vector. Changelog v2: - update the comment in hwprobe. --- arch/riscv/include/asm/vector.h | 10 +++++----- arch/riscv/kernel/cpufeature.c | 5 ++++- arch/riscv/kernel/sys_hwprobe.c | 6 +++++- arch/riscv/kernel/vector.c | 5 ++++- arch/riscv/lib/uaccess.S | 2 +- 5 files changed, 19 insertions(+), 9 deletions(-) diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index 731dcd0ed4de..be7d309cca8a 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -37,7 +37,7 @@ static inline u32 riscv_v_flags(void) static __always_inline bool has_vector(void) { - return riscv_has_extension_unlikely(RISCV_ISA_EXT_v); + return riscv_has_extension_unlikely(RISCV_ISA_EXT_ZVE32X); } static inline void __riscv_v_vstate_clean(struct pt_regs *regs) @@ -91,7 +91,7 @@ static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src { asm volatile ( ".option push\n\t" - ".option arch, +v\n\t" + ".option arch, +zve32x\n\t" "vsetvl x0, %2, %1\n\t" ".option pop\n\t" "csrw " __stringify(CSR_VSTART) ", %0\n\t" @@ -109,7 +109,7 @@ static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to, __vstate_csr_save(save_to); asm volatile ( ".option push\n\t" - ".option arch, +v\n\t" + ".option arch, +zve32x\n\t" "vsetvli %0, x0, e8, m8, ta, ma\n\t" "vse8.v v0, (%1)\n\t" "add %1, %1, %0\n\t" @@ -131,7 +131,7 @@ static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_ riscv_v_enable(); asm volatile ( ".option push\n\t" - ".option arch, +v\n\t" + ".option arch, +zve32x\n\t" "vsetvli %0, x0, e8, m8, ta, ma\n\t" "vle8.v v0, (%1)\n\t" "add %1, %1, %0\n\t" @@ -153,7 +153,7 @@ static inline void __riscv_v_vstate_discard(void) riscv_v_enable(); asm volatile ( ".option push\n\t" - ".option arch, +v\n\t" + ".option arch, +zve32x\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" diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index ad3e613ee30f..53be3365e302 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -720,11 +720,14 @@ void __init riscv_fill_hwcap(void) elf_hwcap &= ~COMPAT_HWCAP_ISA_F; } - if (elf_hwcap & COMPAT_HWCAP_ISA_V) { + if (__riscv_isa_extension_available(NULL, RISCV_ISA_EXT_ZVE32X)) { /* * This cannot fail when called on the boot hart */ riscv_v_setup_vsize(); + } + + if (elf_hwcap & COMPAT_HWCAP_ISA_V) { /* * ISA string in device tree might have 'v' flag, but * CONFIG_RISCV_ISA_V is disabled in kernel. diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c index 35390b4a5a17..83fcc939df67 100644 --- a/arch/riscv/kernel/sys_hwprobe.c +++ b/arch/riscv/kernel/sys_hwprobe.c @@ -69,7 +69,7 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair, if (riscv_isa_extension_available(NULL, c)) pair->value |= RISCV_HWPROBE_IMA_C; - if (has_vector()) + if (has_vector() && riscv_isa_extension_available(NULL, v)) pair->value |= RISCV_HWPROBE_IMA_V; /* @@ -113,6 +113,10 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair, EXT_KEY(ZICOND); EXT_KEY(ZIHINTPAUSE); + /* + * All the following extensions must depend on the kernel + * support of V. + */ if (has_vector()) { EXT_KEY(ZVE32X); EXT_KEY(ZVE32F); diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c index 6727d1d3b8f2..682b3feee451 100644 --- a/arch/riscv/kernel/vector.c +++ b/arch/riscv/kernel/vector.c @@ -173,8 +173,11 @@ bool riscv_v_first_use_handler(struct pt_regs *regs) u32 __user *epc = (u32 __user *)regs->epc; u32 insn = (u32)regs->badaddr; + if (!has_vector()) + return false; + /* Do not handle if V is not supported, or disabled */ - if (!(ELF_HWCAP & COMPAT_HWCAP_ISA_V)) + if (!riscv_v_vstate_ctrl_user_allowed()) return false; /* If V has been enabled then it is not the first-use trap */ diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S index bc22c078aba8..bbe143bb32a0 100644 --- a/arch/riscv/lib/uaccess.S +++ b/arch/riscv/lib/uaccess.S @@ -14,7 +14,7 @@ SYM_FUNC_START(__asm_copy_to_user) #ifdef CONFIG_RISCV_ISA_V - ALTERNATIVE("j fallback_scalar_usercopy", "nop", 0, RISCV_ISA_EXT_v, CONFIG_RISCV_ISA_V) + ALTERNATIVE("j fallback_scalar_usercopy", "nop", 0, RISCV_ISA_EXT_ZVE32X, CONFIG_RISCV_ISA_V) REG_L t0, riscv_v_usercopy_threshold bltu a2, t0, fallback_scalar_usercopy tail enter_vector_usercopy -- 2.44.0.rc2
