From: Rohit Mathew <rohit.mathew@arm.com> maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I8T2RT Reference: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/... --------------------------- mpam v0.1 and versions above v1.0 support optional long counter for memory bandwidth monitoring. The MPAMF_MBWUMON_IDR register have fields indicating support for long counters. As of now, a 44 bit counter represented by HAS_LONG field (bit 30) and a 63 bit counter represented by LWD (bit 29) can be optionally integrated. Probe for these counters and set corresponding feature bits if any of these counters are present. Signed-off-by: Rohit Mathew <rohit.mathew@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Zeng Heng <zengheng4@huawei.com> --- drivers/platform/mpam/mpam_devices.c | 22 ++++++++++++++++++++++ drivers/platform/mpam/mpam_internal.h | 7 +++++++ 2 files changed, 29 insertions(+) diff --git a/drivers/platform/mpam/mpam_devices.c b/drivers/platform/mpam/mpam_devices.c index 930e14471378..c2c5dfa77083 100644 --- a/drivers/platform/mpam/mpam_devices.c +++ b/drivers/platform/mpam/mpam_devices.c @@ -653,6 +653,7 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) pr_err_once("Counters are not usable because not-ready timeout was not provided by firmware."); } if (FIELD_GET(MPAMF_MSMON_IDR_MSMON_MBWU, msmon_features)) { + bool has_long; u32 mbwumonidr = mpam_read_partsel_reg(msc, MBWUMON_IDR); props->num_mbwu_mon = FIELD_GET(MPAMF_MBWUMON_IDR_NUM_MON, mbwumonidr); @@ -661,6 +662,27 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) if (FIELD_GET(MPAMF_MBWUMON_IDR_HAS_RWBW, mbwumonidr)) mpam_set_feature(mpam_feat_msmon_mbwu_rwbw, props); + + /* + * Treat long counter and its extension, lwd as mutually + * exclusive feature bits. Though these are dependent + * fields at the implementation level, there would never + * be a need for mpam_feat_msmon_mbwu_44counter (long + * counter) and mpam_feat_msmon_mbwu_63counter (lwd) + * bits to be set together. + * + * mpam_feat_msmon_mbwu isn't treated as an exclusive + * bit as this feature bit would be used as the "front + * facing feature bit" for any checks related to mbwu + * monitors. + */ + has_long = FIELD_GET(MPAMF_MBWUMON_IDR_HAS_LONG, mbwumonidr); + if (props->num_mbwu_mon && has_long) { + if (FIELD_GET(MPAMF_MBWUMON_IDR_LWD, mbwumonidr)) + mpam_set_feature(mpam_feat_msmon_mbwu_63counter, props); + else + mpam_set_feature(mpam_feat_msmon_mbwu_44counter, props); + } } } diff --git a/drivers/platform/mpam/mpam_internal.h b/drivers/platform/mpam/mpam_internal.h index 320036851777..7ce7587202bf 100644 --- a/drivers/platform/mpam/mpam_internal.h +++ b/drivers/platform/mpam/mpam_internal.h @@ -88,7 +88,14 @@ enum mpam_device_features { mpam_feat_msmon, mpam_feat_msmon_csu, mpam_feat_msmon_csu_capture, + /* + * Having mpam_feat_msmon_mbwu set doesn't mean the regular 31 bit MBWU + * counter would be used. The exact counter used is decided based on the + * status of mpam_feat_msmon_mbwu_l/mpam_feat_msmon_mbwu_lwd as well. + */ mpam_feat_msmon_mbwu, + mpam_feat_msmon_mbwu_44counter, + mpam_feat_msmon_mbwu_63counter, mpam_feat_msmon_mbwu_capture, mpam_feat_msmon_mbwu_rwbw, mpam_feat_msmon_capt, -- 2.25.1