From nobody Tue Feb 10 08:01:10 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B1A1437F0FA for ; Mon, 12 Jan 2026 17:02:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768237371; cv=none; b=MvopoAsaU15tugC15X9vYaCYtxAHtMnhqNLB7xNrYo0RhR8ITF+/rEO+hv4rNQT+VtujPJ1ZwSYmTMfd0lvOyTQa1yRD8C9a66ujrJIg77klmDwHyJRak3yiBsOY5Fp5Mw6cGlSUk+z/Y6rait3RU472azfMhrMHpQt9dD8MrSI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768237371; c=relaxed/simple; bh=zhMZZs1i94LApS14sfoltW2wqXmvqCFPStaTi5GmC+o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ThN2MQtkMazybfE+0stHRsX1q+nk/NJ++mtbOsyCCEYqnl4UyyYhw8KvuHnweU0+QyfbGH3XKImC1LJt1EJCQnM/k/dc+wyizbxCggZXBUwc3TDezKuyvjbNIHwf57vE4xsfSOEJwG6+THjDazIuE6t9vzU7+G5jdIn6dOxY21Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3B811153B; Mon, 12 Jan 2026 09:02:39 -0800 (PST) Received: from e134344.cambridge.arm.com (e134344.arm.com [10.1.196.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id CE8AF3F694; Mon, 12 Jan 2026 09:02:40 -0800 (PST) From: Ben Horgan To: ben.horgan@arm.com Cc: amitsinght@marvell.com, baisheng.gao@unisoc.com, baolin.wang@linux.alibaba.com, carl@os.amperecomputing.com, dave.martin@arm.com, david@kernel.org, dfustini@baylibre.com, fenghuay@nvidia.com, gshan@redhat.com, james.morse@arm.com, jonathan.cameron@huawei.com, kobak@nvidia.com, lcherian@marvell.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, peternewman@google.com, punit.agrawal@oss.qualcomm.com, quic_jiles@quicinc.com, reinette.chatre@intel.com, rohit.mathew@arm.com, scott@os.amperecomputing.com, sdonthineni@nvidia.com, tan.shaopeng@fujitsu.com, xhao@linux.alibaba.com, catalin.marinas@arm.com, will@kernel.org, corbet@lwn.net, maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, kvmarm@lists.linux.dev Subject: [PATCH v3 32/47] arm_mpam: resctrl: Add kunit test for ABMC/CDP interactions Date: Mon, 12 Jan 2026 16:58:59 +0000 Message-ID: <20260112165914.4086692-33-ben.horgan@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260112165914.4086692-1-ben.horgan@arm.com> References: <20260112165914.4086692-1-ben.horgan@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: James Morse ABMC exposes a fun corner case where a platform with one monitor can use ABMC for assignable counters - but not when CDP is enabled. Add some tests. Signed-off-by: James Morse Signed-off-by: Ben Horgan Reviewed-by: Jonathan Cameron --- drivers/resctrl/test_mpam_resctrl.c | 62 +++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) diff --git a/drivers/resctrl/test_mpam_resctrl.c b/drivers/resctrl/test_mpa= m_resctrl.c index a20da161d965..fd63f7bbb147 100644 --- a/drivers/resctrl/test_mpam_resctrl.c +++ b/drivers/resctrl/test_mpam_resctrl.c @@ -344,6 +344,67 @@ static void test_rmid_idx_encoding(struct kunit *test) mpam_pmg_max =3D orig_mpam_pmg_max; } =20 +static void test_num_assignable_counters(struct kunit *test) +{ + unsigned int orig_l3_num_allocated_mbwu =3D l3_num_allocated_mbwu; + u32 orig_mpam_partid_max =3D mpam_partid_max; + u32 orig_mpam_pmg_max =3D mpam_pmg_max; + bool orig_cdp_enabled =3D cdp_enabled; + struct rdt_resource fake_l3; + + /* Force there to be some PARTID/PMG */ + mpam_partid_max =3D 3; + mpam_pmg_max =3D 1; + + cdp_enabled =3D false; + + /* ABMC off, CDP off */ + l3_num_allocated_mbwu =3D resctrl_arch_system_num_rmid_idx(); + mpam_resctrl_monitor_sync_abmc_vals(&fake_l3); + KUNIT_EXPECT_EQ(test, fake_l3.mon.num_mbm_cntrs, resctrl_arch_system_num_= rmid_idx()); + KUNIT_EXPECT_FALSE(test, fake_l3.mon.mbm_cntr_assignable); + KUNIT_EXPECT_FALSE(test, fake_l3.mon.mbm_assign_on_mkdir); + + /* ABMC on, CDP off */ + l3_num_allocated_mbwu =3D 4; + mpam_resctrl_monitor_sync_abmc_vals(&fake_l3); + KUNIT_EXPECT_EQ(test, fake_l3.mon.num_mbm_cntrs, 4); + KUNIT_EXPECT_TRUE(test, fake_l3.mon.mbm_cntr_assignable); + KUNIT_EXPECT_TRUE(test, fake_l3.mon.mbm_assign_on_mkdir); + + cdp_enabled =3D true; + + /* ABMC off, CDP on */ + l3_num_allocated_mbwu =3D resctrl_arch_system_num_rmid_idx(); + mpam_resctrl_monitor_sync_abmc_vals(&fake_l3); + + /* (value not consumed by resctrl) */ + KUNIT_EXPECT_EQ(test, fake_l3.mon.num_mbm_cntrs, resctrl_arch_system_num_= rmid_idx() / 2); + + KUNIT_EXPECT_FALSE(test, fake_l3.mon.mbm_cntr_assignable); + KUNIT_EXPECT_FALSE(test, fake_l3.mon.mbm_assign_on_mkdir); + + /* ABMC on, CDP on */ + l3_num_allocated_mbwu =3D 4; + mpam_resctrl_monitor_sync_abmc_vals(&fake_l3); + KUNIT_EXPECT_EQ(test, fake_l3.mon.num_mbm_cntrs, 2); + KUNIT_EXPECT_TRUE(test, fake_l3.mon.mbm_cntr_assignable); + KUNIT_EXPECT_TRUE(test, fake_l3.mon.mbm_assign_on_mkdir); + + /* ABMC 'on', CDP on - but not enough counters */ + l3_num_allocated_mbwu =3D 1; + mpam_resctrl_monitor_sync_abmc_vals(&fake_l3); + KUNIT_EXPECT_EQ(test, fake_l3.mon.num_mbm_cntrs, 0); + KUNIT_EXPECT_FALSE(test, fake_l3.mon.mbm_cntr_assignable); + KUNIT_EXPECT_FALSE(test, fake_l3.mon.mbm_assign_on_mkdir); + + /* Restore global variables that were messed with */ + l3_num_allocated_mbwu =3D orig_l3_num_allocated_mbwu; + mpam_partid_max =3D orig_mpam_partid_max; + mpam_pmg_max =3D orig_mpam_pmg_max; + cdp_enabled =3D orig_cdp_enabled; +} + static struct kunit_case mpam_resctrl_test_cases[] =3D { KUNIT_CASE(test_get_mba_granularity), KUNIT_CASE_PARAM(test_mbw_max_to_percent, test_percent_value_gen_params), @@ -353,6 +414,7 @@ static struct kunit_case mpam_resctrl_test_cases[] =3D { KUNIT_CASE_PARAM(test_percent_max_roundtrip_stability, test_all_bwa_wd_gen_params), KUNIT_CASE_PARAM(test_rmid_idx_encoding, test_rmid_idx_gen_params), + KUNIT_CASE(test_num_assignable_counters), {} }; =20 --=20 2.43.0