This comment block was taken originally from the MIPS architecture code,
where indeed there are particular assumptions one can make regarding SMP
and !SMP and cycle counters. On LoongArch, however, the rdtime family of
functions is always available. As Xuerui wrote:
The rdtime family of instructions is in fact guaranteed to be
available on LoongArch; LoongArch's subsets all contain them, even
the 32-bit "Primary" subset intended for university teaching -- they
provide the rdtimeh.w and rdtimel.w pair of instructions that access
the same 64-bit counter.
So this commit simply removes the incorrect comment block.
Link: https://lore.kernel.org/lkml/[email protected]/
Fixes: b738c106f735 ("LoongArch: Add other common headers")
Signed-off-by: Jason A. Donenfeld <[email protected]>
---
arch/loongarch/include/asm/timex.h | 7 -------
1 file changed, 7 deletions(-)
diff --git a/arch/loongarch/include/asm/timex.h b/arch/loongarch/include/asm/timex.h
index d3ed99a4fdbd..fb41e9e7a222 100644
--- a/arch/loongarch/include/asm/timex.h
+++ b/arch/loongarch/include/asm/timex.h
@@ -12,13 +12,6 @@
#include <asm/cpu.h>
#include <asm/cpu-features.h>
-/*
- * Standard way to access the cycle counter.
- * Currently only used on SMP for scheduling.
- *
- * We know that all SMP capable CPUs have cycle counters.
- */
-
typedef unsigned long cycles_t;
#define get_cycles get_cycles
--
2.35.1
On 6/4/22 14:35, Jason A. Donenfeld wrote:
> This comment block was taken originally from the MIPS architecture code,
> where indeed there are particular assumptions one can make regarding SMP
> and !SMP and cycle counters. On LoongArch, however, the rdtime family of
> functions is always available. As Xuerui wrote:
>
> The rdtime family of instructions is in fact guaranteed to be
> available on LoongArch; LoongArch's subsets all contain them, even
> the 32-bit "Primary" subset intended for university teaching -- they
> provide the rdtimeh.w and rdtimel.w pair of instructions that access
> the same 64-bit counter.
>
> So this commit simply removes the incorrect comment block.
>
> Link: https://lore.kernel.org/lkml/[email protected]/
> Fixes: b738c106f735 ("LoongArch: Add other common headers")
> Signed-off-by: Jason A. Donenfeld <[email protected]>
> ---
> arch/loongarch/include/asm/timex.h | 7 -------
> 1 file changed, 7 deletions(-)
>
> diff --git a/arch/loongarch/include/asm/timex.h b/arch/loongarch/include/asm/timex.h
> index d3ed99a4fdbd..fb41e9e7a222 100644
> --- a/arch/loongarch/include/asm/timex.h
> +++ b/arch/loongarch/include/asm/timex.h
> @@ -12,13 +12,6 @@
> #include <asm/cpu.h>
> #include <asm/cpu-features.h>
>
> -/*
> - * Standard way to access the cycle counter.
> - * Currently only used on SMP for scheduling.
> - *
> - * We know that all SMP capable CPUs have cycle counters.
> - */
> -
> typedef unsigned long cycles_t;
>
> #define get_cycles get_cycles
Just as previously discussed. Thanks for the quick fixup!
Reviewed-by: WANG Xuerui <[email protected]>