Re: [PATCH] cpufreq: amd-pstate: remove global header file

[Mario Limonciello]

On 5/28/2024 07:09, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> When extra warnings are enabled, gcc points out a global variable
> definition in a header:
>
> In file included from drivers/cpufreq/amd-pstate-ut.c:29:
> include/linux/amd-pstate.h:123:27: error: 'amd_pstate_mode_string' defined but not used [-Werror=unused-const-variable=]
>    123 | static const char * const amd_pstate_mode_string[] = {
>        |                           ^~~~~~~~~~~~~~~~~~~~~~
>
> This header is only included from two files in the same directory,
> and one of them uses only a single definition from it, so clean it
> up by moving most of the contents into the driver that uses them,
> and making shared bits a local header file.
>
> Fixes: 36c5014e5460 ("cpufreq: amd-pstate: optimize driver working mode selection in amd_pstate_param()")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Thanks!

Acked-by: Mario Limonciello <mario.limonciello@xxxxxxx>

> ---
>   MAINTAINERS                                   |  1 -
>   drivers/cpufreq/amd-pstate-ut.c               |  3 +-
>   drivers/cpufreq/amd-pstate.c                  | 34 ++++++++++++++++++-
>   .../linux => drivers/cpufreq}/amd-pstate.h    | 33 ------------------
>   4 files changed, 35 insertions(+), 36 deletions(-)
>   rename {include/linux => drivers/cpufreq}/amd-pstate.h (82%)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 070a39b2b098..35a75ab8ef05 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1107,7 +1107,6 @@ L:	linux-pm@xxxxxxxxxxxxxxx
>   S:	Supported
>   F:	Documentation/admin-guide/pm/amd-pstate.rst
>   F:	drivers/cpufreq/amd-pstate*
> -F:	include/linux/amd-pstate.h
>   F:	tools/power/x86/amd_pstate_tracer/amd_pstate_trace.py
>   
>   AMD PTDMA DRIVER
> diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
> index f04ae67dda37..fc275d41d51e 100644
> --- a/drivers/cpufreq/amd-pstate-ut.c
> +++ b/drivers/cpufreq/amd-pstate-ut.c
> @@ -26,10 +26,11 @@
>   #include <linux/module.h>
>   #include <linux/moduleparam.h>
>   #include <linux/fs.h>
> -#include <linux/amd-pstate.h>
>   
>   #include <acpi/cppc_acpi.h>
>   
> +#include "amd-pstate.h"
> +
>   /*
>    * Abbreviations:
>    * amd_pstate_ut: used as a shortform for AMD P-State unit test.
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 1b7e82a0ad2e..91993647e09e 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -36,7 +36,6 @@
>   #include <linux/delay.h>
>   #include <linux/uaccess.h>
>   #include <linux/static_call.h>
> -#include <linux/amd-pstate.h>
>   #include <linux/topology.h>
>   
>   #include <acpi/processor.h>
> @@ -46,6 +45,8 @@
>   #include <asm/processor.h>
>   #include <asm/cpufeature.h>
>   #include <asm/cpu_device_id.h>
> +
> +#include "amd-pstate.h"
>   #include "amd-pstate-trace.h"
>   
>   #define AMD_PSTATE_TRANSITION_LATENCY	20000
> @@ -53,6 +54,37 @@
>   #define CPPC_HIGHEST_PERF_PERFORMANCE	196
>   #define CPPC_HIGHEST_PERF_DEFAULT	166
>   
> +#define AMD_CPPC_EPP_PERFORMANCE		0x00
> +#define AMD_CPPC_EPP_BALANCE_PERFORMANCE	0x80
> +#define AMD_CPPC_EPP_BALANCE_POWERSAVE		0xBF
> +#define AMD_CPPC_EPP_POWERSAVE			0xFF
> +
> +/*
> + * enum amd_pstate_mode - driver working mode of amd pstate
> + */
> +enum amd_pstate_mode {
> +	AMD_PSTATE_UNDEFINED = 0,
> +	AMD_PSTATE_DISABLE,
> +	AMD_PSTATE_PASSIVE,
> +	AMD_PSTATE_ACTIVE,
> +	AMD_PSTATE_GUIDED,
> +	AMD_PSTATE_MAX,
> +};
> +
> +static const char * const amd_pstate_mode_string[] = {
> +	[AMD_PSTATE_UNDEFINED]   = "undefined",
> +	[AMD_PSTATE_DISABLE]     = "disable",
> +	[AMD_PSTATE_PASSIVE]     = "passive",
> +	[AMD_PSTATE_ACTIVE]      = "active",
> +	[AMD_PSTATE_GUIDED]      = "guided",
> +	NULL,
> +};
> +
> +struct quirk_entry {
> +	u32 nominal_freq;
> +	u32 lowest_freq;
> +};
> +
>   /*
>    * TODO: We need more time to fine tune processors with shared memory solution
>    * with community together.
> diff --git a/include/linux/amd-pstate.h b/drivers/cpufreq/amd-pstate.h
> similarity index 82%
> rename from include/linux/amd-pstate.h
> rename to drivers/cpufreq/amd-pstate.h
> index d58fc022ec46..e6a28e7f4dbf 100644
> --- a/include/linux/amd-pstate.h
> +++ b/drivers/cpufreq/amd-pstate.h
> @@ -1,7 +1,5 @@
>   /* SPDX-License-Identifier: GPL-2.0-only */
>   /*
> - * linux/include/linux/amd-pstate.h
> - *
>    * Copyright (C) 2022 Advanced Micro Devices, Inc.
>    *
>    * Author: Meng Li <li.meng@xxxxxxx>
> @@ -12,11 +10,6 @@
>   
>   #include <linux/pm_qos.h>
>   
> -#define AMD_CPPC_EPP_PERFORMANCE		0x00
> -#define AMD_CPPC_EPP_BALANCE_PERFORMANCE	0x80
> -#define AMD_CPPC_EPP_BALANCE_POWERSAVE		0xBF
> -#define AMD_CPPC_EPP_POWERSAVE			0xFF
> -
>   /*********************************************************************
>    *                        AMD P-state INTERFACE                       *
>    *********************************************************************/
> @@ -108,30 +101,4 @@ struct amd_cpudata {
>   	bool	suspended;
>   };
>   
> -/*
> - * enum amd_pstate_mode - driver working mode of amd pstate
> - */
> -enum amd_pstate_mode {
> -	AMD_PSTATE_UNDEFINED = 0,
> -	AMD_PSTATE_DISABLE,
> -	AMD_PSTATE_PASSIVE,
> -	AMD_PSTATE_ACTIVE,
> -	AMD_PSTATE_GUIDED,
> -	AMD_PSTATE_MAX,
> -};
> -
> -static const char * const amd_pstate_mode_string[] = {
> -	[AMD_PSTATE_UNDEFINED]   = "undefined",
> -	[AMD_PSTATE_DISABLE]     = "disable",
> -	[AMD_PSTATE_PASSIVE]     = "passive",
> -	[AMD_PSTATE_ACTIVE]      = "active",
> -	[AMD_PSTATE_GUIDED]      = "guided",
> -	NULL,
> -};
> -
> -struct quirk_entry {
> -	u32 nominal_freq;
> -	u32 lowest_freq;
> -};
> -
>   #endif /* _LINUX_AMD_PSTATE_H */