From: Anup Patel <anup@brainfault.org>
To: Paul Walmsley <paul.walmsley@sifive.com>,
Anup Patel <Anup.Patel@wdc.com>
Cc: Alistair Francis <Alistair.Francis@wdc.com>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
Radim K <rkrcmar@redhat.com>, Palmer Dabbelt <palmer@sifive.com>,
Damien Le Moal <Damien.LeMoal@wdc.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Christoph Hellwig <hch@infradead.org>,
Atish Patra <Atish.Patra@wdc.com>,
Alexander Graf <graf@amazon.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
"linux-riscv@lists.infradead.org"
<linux-riscv@lists.infradead.org>
Subject: Re: [PATCH v7 02/21] RISC-V: Add bitmap reprensenting ISA features common across CPUs
Date: Thu, 19 Sep 2019 18:26:02 +0530 [thread overview]
Message-ID: <CAAhSdy1n34wi9iR-QViBFo_ApQx-2R6Jkd8Zpvyt9aLB91jDSw@mail.gmail.com> (raw)
In-Reply-To: <20190904161245.111924-4-anup.patel@wdc.com>
Hi Paul,
On Wed, Sep 4, 2019 at 9:43 PM Anup Patel <Anup.Patel@wdc.com> wrote:
>
> This patch adds riscv_isa bitmap which represents Host ISA features
> common across all Host CPUs. The riscv_isa is not same as elf_hwcap
> because elf_hwcap will only have ISA features relevant for user-space
> apps whereas riscv_isa will have ISA features relevant to both kernel
> and user-space apps.
>
> One of the use-case for riscv_isa bitmap is in KVM hypervisor where
> we will use it to do following operations:
>
> 1. Check whether hypervisor extension is available
> 2. Find ISA features that need to be virtualized (e.g. floating
> point support, vector extension, etc.)
I had addressed your previous comments on this patch by
making riscv_isa as bitmap to cover Z-extensions.
Please review it again.
Regards,
Anup
>
> Signed-off-by: Anup Patel <anup.patel@wdc.com>
> Signed-off-by: Atish Patra <atish.patra@wdc.com>
> Reviewed-by: Alexander Graf <graf@amazon.com>
> ---
> arch/riscv/include/asm/hwcap.h | 26 +++++++++++
> arch/riscv/kernel/cpufeature.c | 79 ++++++++++++++++++++++++++++++++--
> 2 files changed, 102 insertions(+), 3 deletions(-)
>
> diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> index 7ecb7c6a57b1..9b657375aa51 100644
> --- a/arch/riscv/include/asm/hwcap.h
> +++ b/arch/riscv/include/asm/hwcap.h
> @@ -8,6 +8,7 @@
> #ifndef __ASM_HWCAP_H
> #define __ASM_HWCAP_H
>
> +#include <linux/bits.h>
> #include <uapi/asm/hwcap.h>
>
> #ifndef __ASSEMBLY__
> @@ -22,5 +23,30 @@ enum {
> };
>
> extern unsigned long elf_hwcap;
> +
> +#define RISCV_ISA_EXT_a ('a' - 'a')
> +#define RISCV_ISA_EXT_c ('c' - 'a')
> +#define RISCV_ISA_EXT_d ('d' - 'a')
> +#define RISCV_ISA_EXT_f ('f' - 'a')
> +#define RISCV_ISA_EXT_h ('h' - 'a')
> +#define RISCV_ISA_EXT_i ('i' - 'a')
> +#define RISCV_ISA_EXT_m ('m' - 'a')
> +#define RISCV_ISA_EXT_s ('s' - 'a')
> +#define RISCV_ISA_EXT_u ('u' - 'a')
> +#define RISCV_ISA_EXT_zicsr (('z' - 'a') + 1)
> +#define RISCV_ISA_EXT_zifencei (('z' - 'a') + 2)
> +#define RISCV_ISA_EXT_zam (('z' - 'a') + 3)
> +#define RISCV_ISA_EXT_ztso (('z' - 'a') + 4)
> +
> +#define RISCV_ISA_EXT_MAX 256
> +
> +unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap);
> +
> +#define riscv_isa_extension_mask(ext) BIT_MASK(RISCV_ISA_EXT_##ext)
> +
> +bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit);
> +#define riscv_isa_extension_available(isa_bitmap, ext) \
> + __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext)
> +
> #endif
> #endif
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index b1ade9a49347..4ce71ce5e290 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -6,21 +6,64 @@
> * Copyright (C) 2017 SiFive
> */
>
> +#include <linux/bitmap.h>
> #include <linux/of.h>
> #include <asm/processor.h>
> #include <asm/hwcap.h>
> #include <asm/smp.h>
>
> unsigned long elf_hwcap __read_mostly;
> +
> +/* Host ISA bitmap */
> +static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
> +
> #ifdef CONFIG_FPU
> bool has_fpu __read_mostly;
> #endif
>
> +/**
> + * riscv_isa_extension_base - Get base extension word
> + *
> + * @isa_bitmap ISA bitmap to use
> + * @returns base extension word as unsigned long value
> + *
> + * NOTE: If isa_bitmap is NULL then Host ISA bitmap will be used.
> + */
> +unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap)
> +{
> + if (!isa_bitmap)
> + return riscv_isa[0];
> + return isa_bitmap[0];
> +}
> +EXPORT_SYMBOL_GPL(riscv_isa_extension_base);
> +
> +/**
> + * __riscv_isa_extension_available - Check whether given extension
> + * is available or not
> + *
> + * @isa_bitmap ISA bitmap to use
> + * @bit bit position of the desired extension
> + * @returns true or false
> + *
> + * NOTE: If isa_bitmap is NULL then Host ISA bitmap will be used.
> + */
> +bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit)
> +{
> + const unsigned long *bmap = (isa_bitmap) ? isa_bitmap : riscv_isa;
> +
> + if (bit >= RISCV_ISA_EXT_MAX)
> + return false;
> +
> + return test_bit(bit, bmap) ? true : false;
> +}
> +EXPORT_SYMBOL_GPL(__riscv_isa_extension_available);
> +
> void riscv_fill_hwcap(void)
> {
> struct device_node *node;
> const char *isa;
> - size_t i;
> + char print_str[BITS_PER_LONG+1];
> + size_t i, j, isa_len;
> static unsigned long isa2hwcap[256] = {0};
>
> isa2hwcap['i'] = isa2hwcap['I'] = COMPAT_HWCAP_ISA_I;
> @@ -32,8 +75,11 @@ void riscv_fill_hwcap(void)
>
> elf_hwcap = 0;
>
> + bitmap_zero(riscv_isa, RISCV_ISA_EXT_MAX);
> +
> for_each_of_cpu_node(node) {
> unsigned long this_hwcap = 0;
> + unsigned long this_isa = 0;
>
> if (riscv_of_processor_hartid(node) < 0)
> continue;
> @@ -43,8 +89,20 @@ void riscv_fill_hwcap(void)
> continue;
> }
>
> - for (i = 0; i < strlen(isa); ++i)
> + i = 0;
> + isa_len = strlen(isa);
> +#if defined(CONFIG_32BIT)
> + if (!strncmp(isa, "rv32", 4))
> + i += 4;
> +#elif defined(CONFIG_64BIT)
> + if (!strncmp(isa, "rv64", 4))
> + i += 4;
> +#endif
> + for (; i < isa_len; ++i) {
> this_hwcap |= isa2hwcap[(unsigned char)(isa[i])];
> + if ('a' <= isa[i] && isa[i] <= 'z')
> + this_isa |= (1UL << (isa[i] - 'a'));
> + }
>
> /*
> * All "okay" hart should have same isa. Set HWCAP based on
> @@ -55,6 +113,11 @@ void riscv_fill_hwcap(void)
> elf_hwcap &= this_hwcap;
> else
> elf_hwcap = this_hwcap;
> +
> + if (riscv_isa[0])
> + riscv_isa[0] &= this_isa;
> + else
> + riscv_isa[0] = this_isa;
> }
>
> /* We don't support systems with F but without D, so mask those out
> @@ -64,7 +127,17 @@ void riscv_fill_hwcap(void)
> elf_hwcap &= ~COMPAT_HWCAP_ISA_F;
> }
>
> - pr_info("elf_hwcap is 0x%lx\n", elf_hwcap);
> + memset(print_str, 0, sizeof(print_str));
> + for (i = 0, j = 0; i < BITS_PER_LONG; i++)
> + if (riscv_isa[0] & BIT_MASK(i))
> + print_str[j++] = (char)('a' + i);
> + pr_info("riscv: ISA extensions %s\n", print_str);
> +
> + memset(print_str, 0, sizeof(print_str));
> + for (i = 0, j = 0; i < BITS_PER_LONG; i++)
> + if (elf_hwcap & BIT_MASK(i))
> + print_str[j++] = (char)('a' + i);
> + pr_info("riscv: ELF capabilities %s\n", print_str);
>
> #ifdef CONFIG_FPU
> if (elf_hwcap & (COMPAT_HWCAP_ISA_F | COMPAT_HWCAP_ISA_D))
> --
> 2.17.1
>
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2019-09-19 12:56 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 16:13 [PATCH v7 00/21] KVM RISC-V Support Anup Patel
2019-09-04 16:13 ` [PATCH v7 01/21] KVM: RISC-V: Add KVM_REG_RISCV for ONE_REG interface Anup Patel
2019-09-19 12:37 ` Paul Walmsley
2019-09-04 16:13 ` [PATCH] RISC-V: Enable KVM for RV64 and RV32 Anup Patel
2019-09-04 16:17 ` Anup Patel
2019-09-04 16:13 ` [PATCH v7 02/21] RISC-V: Add bitmap reprensenting ISA features common across CPUs Anup Patel
2019-09-19 12:56 ` Anup Patel [this message]
2019-09-21 10:01 ` Paul Walmsley
2019-09-23 3:39 ` Anup Patel
2019-09-23 15:54 ` Alistair Francis
2019-09-04 16:14 ` [PATCH v7 03/21] RISC-V: Export few kernel symbols Anup Patel
2019-09-19 12:39 ` Paul Walmsley
2019-09-04 16:14 ` [PATCH v7 04/21] RISC-V: Add hypervisor extension related CSR defines Anup Patel
2019-09-04 16:14 ` [PATCH v7 05/21] RISC-V: Add initial skeletal KVM support Anup Patel
2019-09-04 16:14 ` [PATCH v7 06/21] RISC-V: KVM: Implement VCPU create, init and destroy functions Anup Patel
2019-09-23 6:44 ` Alexander Graf
2019-09-23 12:37 ` Anup Patel
2019-09-04 16:14 ` [PATCH v7 07/21] RISC-V: KVM: Implement VCPU interrupts and requests handling Anup Patel
2019-09-04 16:14 ` [PATCH v7 08/21] RISC-V: KVM: Implement KVM_GET_ONE_REG/KVM_SET_ONE_REG ioctls Anup Patel
2019-09-23 3:42 ` Anup Patel
2019-09-04 16:15 ` [PATCH v7 09/21] RISC-V: KVM: Implement VCPU world-switch Anup Patel
2019-09-04 16:15 ` [PATCH v7 10/21] RISC-V: KVM: Handle MMIO exits for VCPU Anup Patel
2019-09-23 6:50 ` Alexander Graf
2019-09-23 11:12 ` Paolo Bonzini
2019-09-23 13:09 ` Anup Patel
2019-09-23 13:33 ` Paolo Bonzini
2019-09-24 5:07 ` Anup Patel
2019-10-08 22:44 ` Palmer Dabbelt
2019-10-09 4:58 ` Anup Patel
2019-09-04 16:15 ` [PATCH v7 11/21] RISC-V: KVM: Handle WFI " Anup Patel
2019-09-23 6:53 ` Alexander Graf
2019-09-23 12:54 ` Anup Patel
2019-09-04 16:15 ` [PATCH v7 12/21] RISC-V: KVM: Implement VMID allocator Anup Patel
2019-09-04 16:15 ` [PATCH v7 13/21] RISC-V: KVM: Implement stage2 page table programming Anup Patel
2019-09-04 16:15 ` [PATCH v7 14/21] RISC-V: KVM: Implement MMU notifiers Anup Patel
2019-09-04 16:15 ` [PATCH v7 15/21] RISC-V: KVM: Add timer functionality Anup Patel
2019-09-04 16:15 ` [PATCH v7 16/21] RISC-V: KVM: FP lazy save/restore Anup Patel
2019-09-04 16:15 ` [PATCH v7 17/21] RISC-V: KVM: Implement ONE REG interface for FP registers Anup Patel
2019-09-04 16:16 ` [PATCH v7 18/21] RISC-V: KVM: Add SBI v0.1 support Anup Patel
2019-09-05 8:35 ` Andreas Schwab
2019-09-23 7:01 ` Alexander Graf
2019-09-23 12:59 ` Anup Patel
2019-09-04 16:16 ` [PATCH v7 19/21] RISC-V: KVM: Document RISC-V specific parts of KVM API Anup Patel
2019-09-04 16:16 ` [PATCH v7 20/21] RISC-V: Enable VIRTIO drivers in RV64 and RV32 defconfig Anup Patel
2019-09-19 7:54 ` Paul Walmsley
2019-09-04 16:16 ` [PATCH v7 21/21] RISC-V: KVM: Add MAINTAINERS entry Anup Patel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAAhSdy1n34wi9iR-QViBFo_ApQx-2R6Jkd8Zpvyt9aLB91jDSw@mail.gmail.com \
--to=anup@brainfault.org \
--cc=Alistair.Francis@wdc.com \
--cc=Anup.Patel@wdc.com \
--cc=Atish.Patra@wdc.com \
--cc=Damien.LeMoal@wdc.com \
--cc=daniel.lezcano@linaro.org \
--cc=graf@amazon.com \
--cc=hch@infradead.org \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=palmer@sifive.com \
--cc=paul.walmsley@sifive.com \
--cc=pbonzini@redhat.com \
--cc=rkrcmar@redhat.com \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).