From 5f7c6bd95bd6089473db3ba4f033584f5de0ee8a Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Tue, 24 Sep 2024 14:49:32 +0100 Subject: [profile] Standardise return type of profile_timestamp() All consumers of profile_timestamp() currently treat the value as an unsigned long. Only the elapsed number of ticks is ever relevant: the absolute value of the timestamp is not used. Profiling is used to measure short durations that are generally fewer than a million CPU cycles, for which an unsigned long is easily large enough. Standardise the return type of profile_timestamp() as unsigned long across all CPU architectures. This allows 32-bit architectures such as i386 and riscv32 to omit all logic associated with retrieving the upper 32 bits of the 64-bit hardware counter, which simplifies the code and allows riscv32 and riscv64 to share the same implementation. Signed-off-by: Michael Brown --- src/arch/riscv/include/bits/profile.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 src/arch/riscv/include/bits/profile.h (limited to 'src/arch/riscv/include') diff --git a/src/arch/riscv/include/bits/profile.h b/src/arch/riscv/include/bits/profile.h new file mode 100644 index 000000000..e9e003dab --- /dev/null +++ b/src/arch/riscv/include/bits/profile.h @@ -0,0 +1,28 @@ +#ifndef _BITS_PROFILE_H +#define _BITS_PROFILE_H + +/** @file + * + * Profiling + * + */ + +FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); + +#include + +/** + * Get profiling timestamp + * + * @ret timestamp Timestamp + */ +static inline __attribute__ (( always_inline )) unsigned long +profile_timestamp ( void ) { + unsigned long cycles; + + /* Read timestamp counter */ + __asm__ __volatile__ ( "rdcycle %0" : "=r" ( cycles ) ); + return cycles; +} + +#endif /* _BITS_PROFILE_H */ -- cgit v1.2.3-55-g7522