Re: [PATCH] riscv: perf: Drop defining `perf_instruction_pointer()` and `perf_misc_flags()`

[Andrew Jones <ajones@ventanamicro.com>]

On Fri, Nov 15, 2024 at 11:13:45AM +0000, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> With commit 2c47e7a74f44 ("perf/core: Correct perf sampling with guest
> VMs"), the perf core now handles the functionality previously requiring
> arch-specific definitions of `perf_instruction_pointer()` and
> `perf_misc_flags()`. As these definitions are no longer necessary for
> RISC-V, this patch removes their implementation and declarations.
> 
> This cleanup aligns the RISC-V architecture with the updated perf core
> mechanism, reducing code redundancy and improving maintainability.
> 
> Fixes: 2c47e7a74f44 ("perf/core: Correct perf sampling with guest VMs")
> Reported-by: Chris Paterson <Chris.Paterson2@renesas.com>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
>  arch/riscv/include/asm/perf_event.h |  3 ---
>  arch/riscv/kernel/perf_callchain.c  | 28 ----------------------------
>  2 files changed, 31 deletions(-)
> 
> diff --git a/arch/riscv/include/asm/perf_event.h b/arch/riscv/include/asm/perf_event.h
> index 38926b4a902d..bcc928fd3785 100644
> --- a/arch/riscv/include/asm/perf_event.h
> +++ b/arch/riscv/include/asm/perf_event.h
> @@ -10,9 +10,6 @@
>  
>  #ifdef CONFIG_PERF_EVENTS
>  #include <linux/perf_event.h>
> -extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
> -extern unsigned long perf_misc_flags(struct pt_regs *regs);
> -#define perf_misc_flags(regs) perf_misc_flags(regs)
>  #define perf_arch_bpf_user_pt_regs(regs) (struct user_regs_struct *)regs
>  
>  #define perf_arch_fetch_caller_regs(regs, __ip) { \
> diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c
> index c2c81a80f816..b465bc9eb870 100644
> --- a/arch/riscv/kernel/perf_callchain.c
> +++ b/arch/riscv/kernel/perf_callchain.c
> @@ -46,31 +46,3 @@ void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry,
>  
>  	walk_stackframe(NULL, regs, fill_callchain, entry);
>  }
> -
> -unsigned long perf_instruction_pointer(struct pt_regs *regs)
> -{
> -	if (perf_guest_state())
> -		return perf_guest_get_ip();
> -
> -	return instruction_pointer(regs);
> -}
> -
> -unsigned long perf_misc_flags(struct pt_regs *regs)
> -{
> -	unsigned int guest_state = perf_guest_state();
> -	unsigned long misc = 0;
> -
> -	if (guest_state) {
> -		if (guest_state & PERF_GUEST_USER)
> -			misc |= PERF_RECORD_MISC_GUEST_USER;
> -		else
> -			misc |= PERF_RECORD_MISC_GUEST_KERNEL;
> -	} else {
> -		if (user_mode(regs))
> -			misc |= PERF_RECORD_MISC_USER;
> -		else
> -			misc |= PERF_RECORD_MISC_KERNEL;
> -	}
> -
> -	return misc;
> -}
> -- 
> 2.25.1
>

Reviewed-by: Andrew Jones <ajones@ventanamicro.com>