From 9c7646d5ffd2b8bf720a0b77897f6c5095dfc53b Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Mon, 18 Sep 2023 15:15:22 +0200 Subject: [PATCH] RISC-V: hwprobe: Expose Zicboz extension and its block size Expose Zicboz through hwprobe and also provide a key to extract its respective block size. Opportunistically add a macro and apply it to current extensions in order to avoid duplicating code. Signed-off-by: Andrew Jones Reviewed-by: Evan Green Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230918131518.56803-11-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt --- Documentation/riscv/hwprobe.rst | 6 ++++ arch/riscv/include/asm/hwprobe.h | 2 +- arch/riscv/include/uapi/asm/hwprobe.h | 2 ++ arch/riscv/kernel/sys_riscv.c | 44 +++++++++++++++++++-------- 4 files changed, 40 insertions(+), 14 deletions(-) diff --git a/Documentation/riscv/hwprobe.rst b/Documentation/riscv/hwprobe.rst index a52996b22f75..7b2384de471f 100644 --- a/Documentation/riscv/hwprobe.rst +++ b/Documentation/riscv/hwprobe.rst @@ -77,6 +77,9 @@ The following keys are defined: * :c:macro:`RISCV_HWPROBE_EXT_ZBS`: The Zbs extension is supported, as defined in version 1.0 of the Bit-Manipulation ISA extensions. + * :c:macro:`RISCV_HWPROBE_EXT_ZICBOZ`: The Zicboz extension is supported, as + ratified in commit 3dd606f ("Create cmobase-v1.0.pdf") of riscv-CMOs. + * :c:macro:`RISCV_HWPROBE_KEY_CPUPERF_0`: A bitmask that contains performance information about the selected set of processors. @@ -96,3 +99,6 @@ The following keys are defined: * :c:macro:`RISCV_HWPROBE_MISALIGNED_UNSUPPORTED`: Misaligned accesses are not supported at all and will generate a misaligned address fault. + +* :c:macro:`RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE`: An unsigned int which + represents the size of the Zicboz block in bytes. diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h index 78936f4ff513..39df8604fea1 100644 --- a/arch/riscv/include/asm/hwprobe.h +++ b/arch/riscv/include/asm/hwprobe.h @@ -8,6 +8,6 @@ #include -#define RISCV_HWPROBE_MAX_KEY 5 +#define RISCV_HWPROBE_MAX_KEY 6 #endif diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h index 006bfb48343d..86d08a0e617b 100644 --- a/arch/riscv/include/uapi/asm/hwprobe.h +++ b/arch/riscv/include/uapi/asm/hwprobe.h @@ -29,6 +29,7 @@ struct riscv_hwprobe { #define RISCV_HWPROBE_EXT_ZBA (1 << 3) #define RISCV_HWPROBE_EXT_ZBB (1 << 4) #define RISCV_HWPROBE_EXT_ZBS (1 << 5) +#define RISCV_HWPROBE_EXT_ZICBOZ (1 << 6) #define RISCV_HWPROBE_KEY_CPUPERF_0 5 #define RISCV_HWPROBE_MISALIGNED_UNKNOWN (0 << 0) #define RISCV_HWPROBE_MISALIGNED_EMULATED (1 << 0) @@ -36,6 +37,7 @@ struct riscv_hwprobe { #define RISCV_HWPROBE_MISALIGNED_FAST (3 << 0) #define RISCV_HWPROBE_MISALIGNED_UNSUPPORTED (4 << 0) #define RISCV_HWPROBE_MISALIGNED_MASK (7 << 0) +#define RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE 6 /* Increase RISCV_HWPROBE_MAX_KEY when adding items. */ #endif diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c index 473159b5f303..d7266a9abc66 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -145,26 +145,38 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair, for_each_cpu(cpu, cpus) { struct riscv_isainfo *isainfo = &hart_isa[cpu]; - if (riscv_isa_extension_available(isainfo->isa, ZBA)) - pair->value |= RISCV_HWPROBE_EXT_ZBA; - else - missing |= RISCV_HWPROBE_EXT_ZBA; +#define EXT_KEY(ext) \ + do { \ + if (__riscv_isa_extension_available(isainfo->isa, RISCV_ISA_EXT_##ext)) \ + pair->value |= RISCV_HWPROBE_EXT_##ext; \ + else \ + missing |= RISCV_HWPROBE_EXT_##ext; \ + } while (false) - if (riscv_isa_extension_available(isainfo->isa, ZBB)) - pair->value |= RISCV_HWPROBE_EXT_ZBB; - else - missing |= RISCV_HWPROBE_EXT_ZBB; - - if (riscv_isa_extension_available(isainfo->isa, ZBS)) - pair->value |= RISCV_HWPROBE_EXT_ZBS; - else - missing |= RISCV_HWPROBE_EXT_ZBS; + /* + * Only use EXT_KEY() for extensions which can be exposed to userspace, + * regardless of the kernel's configuration, as no other checks, besides + * presence in the hart_isa bitmap, are made. + */ + EXT_KEY(ZBA); + EXT_KEY(ZBB); + EXT_KEY(ZBS); + EXT_KEY(ZICBOZ); +#undef EXT_KEY } /* Now turn off reporting features if any CPU is missing it. */ pair->value &= ~missing; } +static bool hwprobe_ext0_has(const struct cpumask *cpus, unsigned long ext) +{ + struct riscv_hwprobe pair; + + hwprobe_isa_ext0(&pair, cpus); + return (pair.value & ext); +} + static u64 hwprobe_misaligned(const struct cpumask *cpus) { int cpu; @@ -215,6 +227,12 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair, pair->value = hwprobe_misaligned(cpus); break; + case RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE: + pair->value = 0; + if (hwprobe_ext0_has(cpus, RISCV_HWPROBE_EXT_ZICBOZ)) + pair->value = riscv_cboz_block_size; + 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