git: 951788e3733e - main - hwpstate_amd(4): 'epp' sysctl leaf to operate on real EPP hardware values

The branch main has been updated by olce:

URL: https://cgit.FreeBSD.org/src/commit/?id=951788e3733e415ca4721c0a63454937dcb29b2c

commit 951788e3733e415ca4721c0a63454937dcb29b2c
Author:     Olivier Certner <olce@FreeBSD.org>
AuthorDate: 2026-01-27 11:44:29 +0000
Commit:     Olivier Certner <olce@FreeBSD.org>
CommitDate: 2026-02-11 20:43:21 +0000

    hwpstate_amd(4): 'epp' sysctl leaf to operate on real EPP hardware values
    
    We were using percents, for compatibility with hwpstate_intel(4), but
    this looses granularity that might be important in some scenarios or
    with specific CPU models.
    
    For consistency, hwpstate_intel(4) should be changed accordingly, at the
    expense of breaking compatibility.
    
    For release notes: Introduction of hwpstate_amd(4) deserves a release
    note, even if the original commit was not tagged.  Functionality
    introduced by recent commits tagged with "Relnotes" should be mentioned
    along that one.
    
    PR:             292615
    Reviewed by:    aokblast
    Relnotes:       yes
    Sponsored by:   The FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D55009
---
 sys/x86/cpufreq/hwpstate_amd.c | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/sys/x86/cpufreq/hwpstate_amd.c b/sys/x86/cpufreq/hwpstate_amd.c
index 18d420dc7747..c35fe0719d74 100644
--- a/sys/x86/cpufreq/hwpstate_amd.c
+++ b/sys/x86/cpufreq/hwpstate_amd.c
@@ -428,30 +428,25 @@ sysctl_epp_handler(SYSCTL_HANDLER_ARGS)
 {
 	const u_int max_epp =
 	    BITS_VALUE(AMD_CPPC_REQUEST_EPP_BITS, (uint64_t)-1);
-	const device_t dev = oidp->oid_arg1;
+	const device_t dev = arg1;
 	struct hwpstate_softc *const sc = device_get_softc(dev);
 	u_int val;
-	int error = 0;
+	int error;
 
 	/* Sysctl knob does not exist if PSTATE_CPPC is not set. */
 	check_cppc_enabled(sc, __func__);
 
-	val = BITS_VALUE(AMD_CPPC_REQUEST_EPP_BITS, sc->cppc.request) * 100 /
-	    max_epp;
+	val = BITS_VALUE(AMD_CPPC_REQUEST_EPP_BITS, sc->cppc.request);
+
 	error = sysctl_handle_int(oidp, &val, 0, req);
 	if (error != 0 || req->newptr == NULL)
-		goto end;
-	if (val > 100) {
-		error = EINVAL;
-		goto end;
-	}
-	val = (val * max_epp) / 100;
+		return (error);
 
+	if (val > max_epp)
+		return (EINVAL);
 	error = set_cppc_request(dev,
 	    BITS_WITH_VALUE(AMD_CPPC_REQUEST_EPP_BITS, val),
 	    BITS_WITH_VALUE(AMD_CPPC_REQUEST_EPP_BITS, -1));
-
-end:
 	return (error);
 }
 
@@ -924,7 +919,7 @@ hwpstate_attach(device_t dev)
 		    "epp", CTLTYPE_UINT | CTLFLAG_RWTUN | CTLFLAG_MPSAFE, dev, 0,
 		    sysctl_epp_handler, "IU",
 		    "Efficiency/Performance Preference "
-		    "(range from 0, most performant, through 100, most efficient)");
+		    "(range from 0, most performant, through 255, most efficient)");
 	}
 	return (cpufreq_register(dev));
 }