On Sat, Feb 23, 2019 at 1:11 AM Atish Patra <atish.pa...@wdc.com> wrote:
>
> Currently, we set hwcap based on first valid hart from DT. This may not
> be correct always as that hart might not be current booting cpu or may
> have a different capability.
>
> Set hwcap as the capabilities supported by all possible harts with "okay"
> status.
>
> Signed-off-by: Atish Patra <atish.pa...@wdc.com>
> ---
> arch/riscv/kernel/cpufeature.c | 41 ++++++++++++++++++++++-------------------
> 1 file changed, 22 insertions(+), 19 deletions(-)
>
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index e7a4701f..bc29b010 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -20,6 +20,7 @@
> #include <linux/of.h>
> #include <asm/processor.h>
> #include <asm/hwcap.h>
> +#include <asm/smp.h>
>
> unsigned long elf_hwcap __read_mostly;
> #ifdef CONFIG_FPU
> @@ -42,28 +43,30 @@ void riscv_fill_hwcap(void)
>
> elf_hwcap = 0;
>
> - /*
> - * We don't support running Linux on hertergenous ISA systems. For
> - * now, we just check the ISA of the first "okay" processor.
> - */
> for_each_of_cpu_node(node) {
> - if (riscv_of_processor_hartid(node) >= 0)
> - break;
> - }
> - if (!node) {
> - pr_warn("Unable to find \"cpu\" devicetree entry\n");
> - return;
> - }
> + unsigned long this_hwcap = 0;
>
> - if (of_property_read_string(node, "riscv,isa", &isa)) {
> - pr_warn("Unable to find \"riscv,isa\" devicetree entry\n");
> - of_node_put(node);
> - return;
> - }
> - of_node_put(node);
> + if (riscv_of_processor_hartid(node) < 0)
> + continue;
>
> - for (i = 0; i < strlen(isa); ++i)
> - elf_hwcap |= isa2hwcap[(unsigned char)(isa[i])];
> + if (of_property_read_string(node, "riscv,isa", &isa)) {
> + pr_warn("Unable to find \"riscv,isa\" devicetree
> entry\n");
> + continue;
> + }
> +
> + for (i = 0; i < strlen(isa); ++i)
> + this_hwcap |= isa2hwcap[(unsigned char)(isa[i])];
> +
> + /*
> + * All "okay" hart should have same isa. Set HWCAP based on
> + * common capabilities of every "okay" hart, in case they
> don't
> + * have.
> + */
> + if (elf_hwcap)
> + elf_hwcap &= this_hwcap;
> + else
> + elf_hwcap = this_hwcap;
> + }
>
> /* We don't support systems with F but without D, so mask those out
> * here. */
> --
> 2.7.4
>
Looks good to me.
Reviewed-by: Anup Patel <a...@brainfault.org>
Regards,
Anup
