From c6699baf10647b87b075bf6c65d25b4cd52d4830 Mon Sep 17 00:00:00 2001 From: Evan Green Date: Tue, 9 May 2023 11:25:01 -0700 Subject: [PATCH 1/3] RISC-V: Add Zba, Zbs extension probing Add the Zba address bit manipulation extension and Zbs single bit instructions extension into those the kernel is aware of and maintains in its riscv_isa bitmap. Signed-off-by: Evan Green Reviewed-by: Andrew Jones Reviewed-by: Palmer Dabbelt Reviewed-by: Conor Dooley Reviewed-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230509182504.2997252-2-evan@rivosinc.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/hwcap.h | 2 ++ arch/riscv/kernel/cpu.c | 2 ++ arch/riscv/kernel/cpufeature.c | 2 ++ 3 files changed, 6 insertions(+) diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index e0c40a4c63d5..6b2e8ff4638c 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -46,6 +46,8 @@ #define RISCV_ISA_EXT_ZICBOZ 34 #define RISCV_ISA_EXT_SMAIA 35 #define RISCV_ISA_EXT_SSAIA 36 +#define RISCV_ISA_EXT_ZBA 37 +#define RISCV_ISA_EXT_ZBS 38 #define RISCV_ISA_EXT_MAX 64 #define RISCV_ISA_EXT_NAME_LEN_MAX 32 diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index c96aa56cf1c7..bd294364390d 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -184,7 +184,9 @@ static struct riscv_isa_ext_data isa_ext_arr[] = { __RISCV_ISA_EXT_DATA(zicbom, RISCV_ISA_EXT_ZICBOM), __RISCV_ISA_EXT_DATA(zicboz, RISCV_ISA_EXT_ZICBOZ), __RISCV_ISA_EXT_DATA(zihintpause, RISCV_ISA_EXT_ZIHINTPAUSE), + __RISCV_ISA_EXT_DATA(zba, RISCV_ISA_EXT_ZBA), __RISCV_ISA_EXT_DATA(zbb, RISCV_ISA_EXT_ZBB), + __RISCV_ISA_EXT_DATA(zbs, RISCV_ISA_EXT_ZBS), __RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA), __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA), __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF), diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index b1d6b7e4b829..a1954c83638f 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -236,7 +236,9 @@ void __init riscv_fill_hwcap(void) SET_ISA_EXT_MAP("svinval", RISCV_ISA_EXT_SVINVAL); SET_ISA_EXT_MAP("svnapot", RISCV_ISA_EXT_SVNAPOT); SET_ISA_EXT_MAP("svpbmt", RISCV_ISA_EXT_SVPBMT); + SET_ISA_EXT_MAP("zba", RISCV_ISA_EXT_ZBA); SET_ISA_EXT_MAP("zbb", RISCV_ISA_EXT_ZBB); + SET_ISA_EXT_MAP("zbs", RISCV_ISA_EXT_ZBS); SET_ISA_EXT_MAP("zicbom", RISCV_ISA_EXT_ZICBOM); SET_ISA_EXT_MAP("zicboz", RISCV_ISA_EXT_ZICBOZ); SET_ISA_EXT_MAP("zihintpause", RISCV_ISA_EXT_ZIHINTPAUSE); From 82e9c66e81c814e20ee2a3aafb60a9012c79fb40 Mon Sep 17 00:00:00 2001 From: Evan Green Date: Tue, 9 May 2023 11:25:02 -0700 Subject: [PATCH 2/3] RISC-V: Track ISA extensions per hart The kernel maintains a mask of ISA extensions ANDed together across all harts. Let's also keep a bitmap of ISA extensions for each CPU. Although the kernel is currently unlikely to enable a feature that exists only on some CPUs, we want the ability to report asymmetric CPU extensions accurately to usermode. Note that riscv_fill_hwcaps() runs before the per_cpu_offsets are built, which is why I've used a [NR_CPUS] array rather than per_cpu() data. Signed-off-by: Evan Green Reviewed-by: Andrew Jones Reviewed-by: Conor Dooley Reviewed-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20230509182504.2997252-3-evan@rivosinc.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/cpufeature.h | 10 ++++++++++ arch/riscv/kernel/cpufeature.c | 18 ++++++++++++------ 2 files changed, 22 insertions(+), 6 deletions(-) diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h index 808d5403f2ac..23fed53b8815 100644 --- a/arch/riscv/include/asm/cpufeature.h +++ b/arch/riscv/include/asm/cpufeature.h @@ -6,6 +6,9 @@ #ifndef _ASM_CPUFEATURE_H #define _ASM_CPUFEATURE_H +#include +#include + /* * These are probed via a device_initcall(), via either the SBI or directly * from the corresponding CSRs. @@ -16,8 +19,15 @@ struct riscv_cpuinfo { unsigned long mimpid; }; +struct riscv_isainfo { + DECLARE_BITMAP(isa, RISCV_ISA_EXT_MAX); +}; + DECLARE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo); DECLARE_PER_CPU(long, misaligned_access_speed); +/* Per-cpu ISA extensions. */ +extern struct riscv_isainfo hart_isa[NR_CPUS]; + #endif diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index a1954c83638f..e8b7b4b20bb5 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -26,6 +26,9 @@ unsigned long elf_hwcap __read_mostly; /* Host ISA bitmap */ static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly; +/* Per-cpu ISA extensions. */ +struct riscv_isainfo hart_isa[NR_CPUS]; + /* Performance information */ DEFINE_PER_CPU(long, misaligned_access_speed); @@ -113,14 +116,18 @@ void __init riscv_fill_hwcap(void) bitmap_zero(riscv_isa, RISCV_ISA_EXT_MAX); for_each_of_cpu_node(node) { + struct riscv_isainfo *isainfo; unsigned long this_hwcap = 0; - DECLARE_BITMAP(this_isa, RISCV_ISA_EXT_MAX); const char *temp; + unsigned int cpu_id; rc = riscv_of_processor_hartid(node, &hartid); if (rc < 0) continue; + cpu_id = riscv_hartid_to_cpuid(hartid); + isainfo = &hart_isa[cpu_id]; + if (of_property_read_string(node, "riscv,isa", &isa)) { pr_warn("Unable to find \"riscv,isa\" devicetree entry\n"); continue; @@ -137,7 +144,6 @@ void __init riscv_fill_hwcap(void) /* The riscv,isa DT property must start with rv64 or rv32 */ if (temp == isa) continue; - bitmap_zero(this_isa, RISCV_ISA_EXT_MAX); for (; *isa; ++isa) { const char *ext = isa++; const char *ext_end = isa; @@ -215,7 +221,7 @@ void __init riscv_fill_hwcap(void) if ((ext_end - ext == sizeof(name) - 1) && \ !memcmp(ext, name, sizeof(name) - 1) && \ riscv_isa_extension_check(bit)) \ - set_bit(bit, this_isa); \ + set_bit(bit, isainfo->isa); \ } while (false) \ if (unlikely(ext_err)) @@ -225,7 +231,7 @@ void __init riscv_fill_hwcap(void) if (riscv_isa_extension_check(nr)) { this_hwcap |= isa2hwcap[nr]; - set_bit(nr, this_isa); + set_bit(nr, isainfo->isa); } } else { /* sorted alphabetically */ @@ -257,9 +263,9 @@ void __init riscv_fill_hwcap(void) elf_hwcap = this_hwcap; if (bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX)) - bitmap_copy(riscv_isa, this_isa, RISCV_ISA_EXT_MAX); + bitmap_copy(riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX); else - bitmap_and(riscv_isa, riscv_isa, this_isa, RISCV_ISA_EXT_MAX); + bitmap_and(riscv_isa, riscv_isa, isainfo->isa, RISCV_ISA_EXT_MAX); } /* We don't support systems with F but without D, so mask those out From c0baf321038d5fa4273c0dc495d78f39848dd8fc Mon Sep 17 00:00:00 2001 From: Evan Green Date: Tue, 9 May 2023 11:25:03 -0700 Subject: [PATCH 3/3] RISC-V: hwprobe: Expose Zba, Zbb, and Zbs Add two new bits to the IMA_EXT_0 key for ZBA, ZBB, and ZBS extensions. These are accurately reported per CPU. Signed-off-by: Evan Green Reviewed-by: Andrew Jones Reviewed-by: Conor Dooley Reviewed-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230509182504.2997252-4-evan@rivosinc.com Signed-off-by: Palmer Dabbelt --- Documentation/riscv/hwprobe.rst | 10 ++++++ arch/riscv/include/uapi/asm/hwprobe.h | 3 ++ arch/riscv/kernel/sys_riscv.c | 48 +++++++++++++++++++++++---- 3 files changed, 54 insertions(+), 7 deletions(-) diff --git a/Documentation/riscv/hwprobe.rst b/Documentation/riscv/hwprobe.rst index 9f0dd62dcb5d..fb25670ef0e5 100644 --- a/Documentation/riscv/hwprobe.rst +++ b/Documentation/riscv/hwprobe.rst @@ -64,6 +64,16 @@ The following keys are defined: * :c:macro:`RISCV_HWPROBE_IMA_C`: The C extension is supported, as defined by version 2.2 of the RISC-V ISA manual. + * :c:macro:`RISCV_HWPROBE_EXT_ZBA`: The Zba address generation extension is + supported, as defined in version 1.0 of the Bit-Manipulation ISA + extensions. + + * :c:macro:`RISCV_HWPROBE_EXT_ZBB`: The Zbb extension is supported, as defined + in version 1.0 of the Bit-Manipulation ISA extensions. + + * :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_KEY_CPUPERF_0`: A bitmask that contains performance information about the selected set of processors. diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h index 8d745a4ad8a2..853f8f6d9a42 100644 --- a/arch/riscv/include/uapi/asm/hwprobe.h +++ b/arch/riscv/include/uapi/asm/hwprobe.h @@ -25,6 +25,9 @@ struct riscv_hwprobe { #define RISCV_HWPROBE_KEY_IMA_EXT_0 4 #define RISCV_HWPROBE_IMA_FD (1 << 0) #define RISCV_HWPROBE_IMA_C (1 << 1) +#define RISCV_HWPROBE_EXT_ZBA (1 << 2) +#define RISCV_HWPROBE_EXT_ZBB (1 << 3) +#define RISCV_HWPROBE_EXT_ZBS (1 << 4) #define RISCV_HWPROBE_KEY_CPUPERF_0 5 #define RISCV_HWPROBE_MISALIGNED_UNKNOWN (0 << 0) #define RISCV_HWPROBE_MISALIGNED_EMULATED (1 << 0) diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c index 5db29683ebee..fe655db19ab4 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -121,6 +121,46 @@ static void hwprobe_arch_id(struct riscv_hwprobe *pair, pair->value = id; } +static void hwprobe_isa_ext0(struct riscv_hwprobe *pair, + const struct cpumask *cpus) +{ + int cpu; + u64 missing = 0; + + pair->value = 0; + if (has_fpu()) + pair->value |= RISCV_HWPROBE_IMA_FD; + + if (riscv_isa_extension_available(NULL, c)) + pair->value |= RISCV_HWPROBE_IMA_C; + + /* + * Loop through and record extensions that 1) anyone has, and 2) anyone + * doesn't have. + */ + 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; + + 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; + } + + /* Now turn off reporting features if any CPU is missing it. */ + pair->value &= ~missing; +} + static u64 hwprobe_misaligned(const struct cpumask *cpus) { int cpu; @@ -164,13 +204,7 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair, break; case RISCV_HWPROBE_KEY_IMA_EXT_0: - pair->value = 0; - if (has_fpu()) - pair->value |= RISCV_HWPROBE_IMA_FD; - - if (riscv_isa_extension_available(NULL, c)) - pair->value |= RISCV_HWPROBE_IMA_C; - + hwprobe_isa_ext0(pair, cpus); break; case RISCV_HWPROBE_KEY_CPUPERF_0: