On Sun, Jun 9, 2024 at 9:45 PM Charlie Jenkins <charlie@xxxxxxxxxxxx> wrote: > > Add a new hwprobe key "RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0" which > allows userspace to probe for the new RISCV_ISA_VENDOR_EXT_XTHEADVECTOR > vendor extension. > > This new key will allow userspace code to probe for which thead vendor > extensions are supported. This API is modeled to be consistent with > RISCV_HWPROBE_KEY_IMA_EXT_0. The bitmask returned will have each bit > corresponding to a supported thead vendor extension of the cpumask set. > Just like RISCV_HWPROBE_KEY_IMA_EXT_0, this allows a userspace program > to determine all of the supported thead vendor extensions in one call. > > Signed-off-by: Charlie Jenkins <charlie@xxxxxxxxxxxx> > Reviewed-by: Evan Green <evan@xxxxxxxxxxxx> You can continue to keep my tag, but I came up with some nits to pick anyway. > --- > arch/riscv/include/asm/hwprobe.h | 4 +-- > .../include/asm/vendor_extensions/thead_hwprobe.h | 18 +++++++++++ > .../include/asm/vendor_extensions/vendor_hwprobe.h | 37 ++++++++++++++++++++++ > arch/riscv/include/uapi/asm/hwprobe.h | 3 +- > arch/riscv/include/uapi/asm/vendor/thead.h | 3 ++ > arch/riscv/kernel/sys_hwprobe.c | 5 +++ > arch/riscv/kernel/vendor_extensions/Makefile | 1 + > .../riscv/kernel/vendor_extensions/thead_hwprobe.c | 19 +++++++++++ > 8 files changed, 87 insertions(+), 3 deletions(-) > > diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h > index 630507dff5ea..e68496b4f8de 100644 > --- a/arch/riscv/include/asm/hwprobe.h > +++ b/arch/riscv/include/asm/hwprobe.h > @@ -1,6 +1,6 @@ > /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > /* > - * Copyright 2023 Rivos, Inc > + * Copyright 2023-2024 Rivos, Inc > */ > > #ifndef _ASM_HWPROBE_H > @@ -8,7 +8,7 @@ > > #include <uapi/asm/hwprobe.h> > > -#define RISCV_HWPROBE_MAX_KEY 6 > +#define RISCV_HWPROBE_MAX_KEY 7 > > static inline bool riscv_hwprobe_key_is_valid(__s64 key) > { > diff --git a/arch/riscv/include/asm/vendor_extensions/thead_hwprobe.h b/arch/riscv/include/asm/vendor_extensions/thead_hwprobe.h > new file mode 100644 > index 000000000000..925fef39a2c0 > --- /dev/null > +++ b/arch/riscv/include/asm/vendor_extensions/thead_hwprobe.h > @@ -0,0 +1,18 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#ifndef _ASM_RISCV_VENDOR_EXTENSIONS_THEAD_HWPROBE_H > +#define _ASM_RISCV_VENDOR_EXTENSIONS_THEAD_HWPROBE_H > + > +#include <linux/cpumask.h> > + > +#include <uapi/asm/hwprobe.h> > + > +#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_THEAD > +void hwprobe_isa_vendor_ext_thead_0(struct riscv_hwprobe *pair, const struct cpumask *cpus); > +#else > +static inline void hwprobe_isa_vendor_ext_thead_0(struct riscv_hwprobe *pair, const struct cpumask *cpus) > +{ > + pair->value = 0; > +} > +#endif > + > +#endif > diff --git a/arch/riscv/include/asm/vendor_extensions/vendor_hwprobe.h b/arch/riscv/include/asm/vendor_extensions/vendor_hwprobe.h > new file mode 100644 > index 000000000000..b6222e7b519e > --- /dev/null > +++ b/arch/riscv/include/asm/vendor_extensions/vendor_hwprobe.h > @@ -0,0 +1,37 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Copyright 2024 Rivos, Inc > + */ > + > +#ifndef _ASM_RISCV_SYS_HWPROBE_H > +#define _ASM_RISCV_SYS_HWPROBE_H > + > +#include <asm/cpufeature.h> > + > +#define EXT_KEY(ext) \ Nit: Do you think it should be VENDOR_EXT_KEY? I had a slight ping of worry that the identifier sounds so generic it might conflict with something later, but meh maybe it's fine. > + do { \ > + if (__riscv_isa_extension_available(isainfo->isa, RISCV_ISA_VENDOR_EXT_##ext)) \ > + pair->value |= RISCV_HWPROBE_VENDOR_EXT_##ext; \ > + else \ > + missing |= RISCV_HWPROBE_VENDOR_EXT_##ext; \ > + } while (false) > + > +/* > + * Loop through and record extensions that 1) anyone has, and 2) anyone > + * doesn't have. > + * > + * _extension_checks is an arbitrary C block to set the values of pair->value > + * and missing. It should be filled with EXT_KEY expressions. > + */ > +#define VENDOR_EXTENSION_SUPPORTED(pair, cpus, per_hart_thead_bitmap, _extension_checks) \ Nit: This macro was meant to be generic for all vendors, but you've named one of the parameters per_hart_thead_bitmap. :) > + do { \ > + int cpu; \ > + u64 missing; \ > + for_each_cpu(cpu, (cpus)) { \ > + struct riscv_isavendorinfo *isainfo = &(per_hart_thead_bitmap)[cpu]; \ > + _extension_checks \ > + } \ > + (pair)->value &= ~missing; \ > + } while (false) \ > + > +#endif /* _ASM_RISCV_SYS_HWPROBE_H */ > diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h > index dda76a05420b..155a83dd1cdf 100644 > --- a/arch/riscv/include/uapi/asm/hwprobe.h > +++ b/arch/riscv/include/uapi/asm/hwprobe.h > @@ -1,6 +1,6 @@ > /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > /* > - * Copyright 2023 Rivos, Inc > + * Copyright 2023-2024 Rivos, Inc > */ > > #ifndef _UAPI_ASM_HWPROBE_H > @@ -68,6 +68,7 @@ struct riscv_hwprobe { > #define RISCV_HWPROBE_MISALIGNED_UNSUPPORTED (4 << 0) > #define RISCV_HWPROBE_MISALIGNED_MASK (7 << 0) > #define RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE 6 > +#define RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 7 > /* Increase RISCV_HWPROBE_MAX_KEY when adding items. */ > > /* Flags */ > diff --git a/arch/riscv/include/uapi/asm/vendor/thead.h b/arch/riscv/include/uapi/asm/vendor/thead.h > new file mode 100644 > index 000000000000..43790ebe5faf > --- /dev/null > +++ b/arch/riscv/include/uapi/asm/vendor/thead.h > @@ -0,0 +1,3 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > + > +#define RISCV_HWPROBE_VENDOR_EXT_XTHEADVECTOR (1 << 0) > diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c > index 969ef3d59dbe..e39fa70083d3 100644 > --- a/arch/riscv/kernel/sys_hwprobe.c > +++ b/arch/riscv/kernel/sys_hwprobe.c > @@ -13,6 +13,7 @@ > #include <asm/uaccess.h> > #include <asm/unistd.h> > #include <asm/vector.h> > +#include <asm/vendor_extensions/thead_hwprobe.h> > #include <vdso/vsyscall.h> > > > @@ -217,6 +218,10 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair, > pair->value = riscv_cboz_block_size; > break; > > + case RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0: > + hwprobe_isa_vendor_ext_thead_0(pair, cpus); > + break; > + > /* > * For forward compatibility, unknown keys don't fail the whole > * call, but get their element key set to -1 and value set to 0 > diff --git a/arch/riscv/kernel/vendor_extensions/Makefile b/arch/riscv/kernel/vendor_extensions/Makefile > index 353522cb3bf0..866414c81a9f 100644 > --- a/arch/riscv/kernel/vendor_extensions/Makefile > +++ b/arch/riscv/kernel/vendor_extensions/Makefile > @@ -2,3 +2,4 @@ > > obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_ANDES) += andes.o > obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_THEAD) += thead.o > +obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_THEAD) += thead_hwprobe.o > diff --git a/arch/riscv/kernel/vendor_extensions/thead_hwprobe.c b/arch/riscv/kernel/vendor_extensions/thead_hwprobe.c > new file mode 100644 > index 000000000000..53f65942f7e8 > --- /dev/null > +++ b/arch/riscv/kernel/vendor_extensions/thead_hwprobe.c > @@ -0,0 +1,19 @@ > +// SPDX-License-Identifier: GPL-2.0-only > + > +#include <asm/vendor_extensions/thead.h> > +#include <asm/vendor_extensions/thead_hwprobe.h> > +#include <asm/vendor_extensions/vendor_hwprobe.h> > + > +#include <linux/cpumask.h> > +#include <linux/types.h> > + > +#include <uapi/asm/hwprobe.h> > +#include <uapi/asm/vendor/thead.h> > + > +void hwprobe_isa_vendor_ext_thead_0(struct riscv_hwprobe *pair, const struct cpumask *cpus) > +{ > + VENDOR_EXTENSION_SUPPORTED(pair, cpus, > + riscv_isa_vendor_ext_list_thead.per_hart_isa_bitmap, { > + EXT_KEY(XTHEADVECTOR); > + }); > +} > > -- > 2.44.0 >