Re: [PATCH Resend 2/8] tools/power x86_energy_perf_policy: enable AMD pstate EPP profile switching on MSR based system

[Mario Limonciello <mario.limonciello@amd.com>]

On 1/29/2024 23:56, Perry Yuan wrote:
> From: Perry Yuan <Perry.Yuan@amd.com>
> 
> x86_energy_perf_policy adds AMD EPP profiles switch support,the EPP
> driver also has four EPP profiles implemented under power
> firmware autonomous mode.
> (performance, balance-performance, balance-power, power)
> User can choose the new profile to use with this utility support while
> `amd_pstate_epp` driver instance loaded for the MSR support systems.
> 
> for example:
> $ sudo x86_energy_perf_policy -d --hwp-epp balance-performance
> cpu0: old: HWP_REQ: min 13 max 166 des 0 epp 128 window 0x9 (9*10^0us) use_pkg 0
> cpu0: HWP_CAP: low 13 eff 157 guar 0 high 231
> cpu0: new: HWP_REQ: min 13 max 166 des 0 epp 128 window 0x9 (9*10^0us) use_pkg 0
> cpu1: old: HWP_REQ: min 13 max 166 des 0 epp 128 window 0x9 (9*10^0us) use_pkg 0
> cpu1: HWP_CAP: low 13 eff 157 guar 0 high 236
> cpu1: new: HWP_REQ: min 13 max 166 des 0 epp 128 window 0x9 (9*10^0us) use_pkg 0
> cpu2: old: HWP_REQ: min 13 max 166 des 0 epp 128 window 0x9 (9*10^0us) use_pkg 0
> cpu2: HWP_CAP: low 13 eff 157 guar 0 high 211
> cpu2: new: HWP_REQ: min 13 max 166 des 0 epp 128 window 0x9 (9*10^0us) use_pkg 0
> cpu3: old: HWP_REQ: min 13 max 166 des 0 epp 128 window 0x9 (9*10^0us) use_pkg 0
> cpu3: HWP_CAP: low 13 eff 157 guar 0 high 206
> cpu3: new: HWP_REQ: min 13 max 166 des 0 epp 128 window 0x9 (9*10^0us) use_pkg 0
> 
> Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
> ---
>   .../x86_energy_perf_policy.c                  | 69 +++++++++++++++----
>   1 file changed, 54 insertions(+), 15 deletions(-)
> 
> diff --git a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
> index 5daf1c2bb601..da9087873915 100644
> --- a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
> +++ b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
> @@ -902,14 +902,23 @@ void write_hwp_request(int cpu, struct msr_hwp_request *hwp_req, unsigned int ms
>   			hwp_req->hwp_desired, hwp_req->hwp_epp,
>   			hwp_req->hwp_window, hwp_req->hwp_use_pkg);
>   
> -	msr |= HWP_MIN_PERF(ratio_2_msr_perf(hwp_req->hwp_min));
> -	msr |= HWP_MAX_PERF(ratio_2_msr_perf(hwp_req->hwp_max));
> -	msr |= HWP_DESIRED_PERF(ratio_2_msr_perf(hwp_req->hwp_desired));
> -	msr |= HWP_ENERGY_PERF_PREFERENCE(hwp_req->hwp_epp);
> -	msr |= HWP_ACTIVITY_WINDOW(hwp_req->hwp_window);
> -	msr |= HWP_PACKAGE_CONTROL(hwp_req->hwp_use_pkg);
> -
> -	put_msr(cpu, msr_offset, msr);
> +	if (genuine_intel) {
> +		msr |= HWP_MIN_PERF(ratio_2_msr_perf(hwp_req->hwp_min));
> +		msr |= HWP_MAX_PERF(ratio_2_msr_perf(hwp_req->hwp_max));
> +		msr |= HWP_DESIRED_PERF(ratio_2_msr_perf(hwp_req->hwp_desired));
> +		msr |= HWP_ENERGY_PERF_PREFERENCE(hwp_req->hwp_epp);
> +		msr |= HWP_ACTIVITY_WINDOW(hwp_req->hwp_window);
> +		msr |= HWP_PACKAGE_CONTROL(hwp_req->hwp_use_pkg);
> +		put_msr(cpu, msr_offset, msr);
> +	} else if (authentic_amd) {
> +		/* AMD EPP need to set desired perf with zero */
> +		hwp_req->hwp_desired = 0;

Should this be blocked a level higher up?  Like exiting the tool the 
function call when calling parse_cmdline_hwp_desired() is used?

> +		msr |= AMD_CPPC_MIN_PERF(hwp_req->hwp_min);
> +		msr |= AMD_CPPC_MAX_PERF(hwp_req->hwp_max);
> +		msr |= AMD_CPPC_DES_PERF(hwp_req->hwp_desired);

Given the msr is already initialized to 0, this is unnecessary isn't it?

> +		msr |= AMD_CPPC_ENERGY_PERF_PREF(hwp_req->hwp_epp);
> +		amd_put_msr(cpu, msr_offset, (unsigned int)msr);
> +	}
>   }
>   
>   static int get_epb(int cpu)
> @@ -1157,8 +1166,12 @@ int update_hwp_request(int cpu)
>   {
>   	struct msr_hwp_request req;
>   	struct msr_hwp_cap cap;
> +	int msr_offset = 0;
>   
> -	int msr_offset = MSR_HWP_REQUEST;
> +	if (genuine_intel)
> +		msr_offset = MSR_HWP_REQUEST;
> +	else if (authentic_amd)
> +		msr_offset = MSR_AMD_CPPC_REQ;
>   
>   	read_hwp_request(cpu, &req, msr_offset);
>   	if (debug)
> @@ -1181,7 +1194,11 @@ int update_hwp_request(int cpu)
>   
>   	req.hwp_use_pkg = req_update.hwp_use_pkg;
>   
> -	read_hwp_cap(cpu, &cap, MSR_HWP_CAPABILITIES);
> +	if (genuine_intel)
> +		read_hwp_cap(cpu, &cap, MSR_HWP_CAPABILITIES);
> +	else if (authentic_amd)
> +		read_hwp_cap(cpu, &cap, MSR_AMD_CPPC_CAP1);
> +
>   	if (debug)
>   		print_hwp_cap(cpu, &cap, "");
>   
> @@ -1203,8 +1220,12 @@ int update_hwp_request_pkg(int pkg)
>   	struct msr_hwp_request req;
>   	struct msr_hwp_cap cap;
>   	int cpu = first_cpu_in_pkg[pkg];
> +	int msr_offset = 0;
>   
> -	int msr_offset = MSR_HWP_REQUEST_PKG;
> +	if (genuine_intel)
> +		msr_offset = MSR_HWP_REQUEST_PKG;
> +	else if (authentic_amd)
> +		msr_offset = MSR_AMD_CPPC_REQ;
>   
>   	read_hwp_request(cpu, &req, msr_offset);
>   	if (debug)
> @@ -1225,7 +1246,11 @@ int update_hwp_request_pkg(int pkg)
>   	if (update_hwp_epp)
>   		req.hwp_epp = req_update.hwp_epp;
>   
> -	read_hwp_cap(cpu, &cap, MSR_HWP_CAPABILITIES);
> +	if (genuine_intel)
> +		read_hwp_cap(cpu, &cap, MSR_HWP_CAPABILITIES);
> +	else if (authentic_amd)
> +		read_hwp_cap(cpu, &cap, MSR_AMD_CPPC_CAP1);
> +
>   	if (debug)
>   		print_hwp_cap(cpu, &cap, "");
>   
> @@ -1246,13 +1271,27 @@ int update_hwp_request_pkg(int pkg)
>   int enable_hwp_on_cpu(int cpu)
>   {
>   	unsigned long long msr;
> +	int ret;
> +
> +	if (genuine_intel) {
> +		get_msr(cpu, MSR_PM_ENABLE, &msr);
> +		put_msr(cpu, MSR_PM_ENABLE, 1);
> +	} else if (authentic_amd) {
> +		ret = amd_get_msr(cpu, MSR_AMD_CPPC_ENABLE, (unsigned long *)(&msr));
> +		if (ret < 0)
> +			errx(-1, "failed to get msr with return %d", ret);
>   
> -	get_msr(cpu, MSR_PM_ENABLE, &msr);
> -	put_msr(cpu, MSR_PM_ENABLE, 1);
> +		ret = amd_put_msr(cpu, MSR_AMD_CPPC_ENABLE, 1);
> +		if (ret < 0)
> +			errx(-1, "failed to put msr with return %d", ret);
> +	}
>   
> -	if (verbose)
> +	if (verbose && genuine_intel)
>   		printf("cpu%d: MSR_PM_ENABLE old: %d new: %d\n", cpu, (unsigned int) msr, 1);
>   
> +	if (verbose && authentic_amd)
> +		printf("cpu%d: MSR_AMD_CPPC_ENABLE old: %d new: %d\n", cpu, (unsigned int) msr, 1);
> +
>   	return 0;
>   }
>