From 41e8a14950e1732af51cfec8fa09f8ded02a5ca9 Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 19 Nov 2025 12:22:57 +0000 Subject: arm_mpam: Track bandwidth counter state for power management Bandwidth counters need to run continuously to correctly reflect the bandwidth. Save the counter state when the hardware is reset due to CPU hotplug. Add struct mbwu_state to track the bandwidth counter. Support for tracking overflow with the same structure will be added in a subsequent commit. Cc: Zeng Heng Reviewed-by: Gavin Shan Reviewed-by: Zeng Heng Reviewed-by: Jonathan Cameron Reviewed-by: Shaopeng Tan Reviewed-by: Fenghua Yu Tested-by: Carl Worth Tested-by: Gavin Shan Tested-by: Zeng Heng Tested-by: Shaopeng Tan Tested-by: Hanjun Guo Signed-off-by: James Morse Signed-off-by: Ben Horgan Signed-off-by: Catalin Marinas --- drivers/resctrl/mpam_internal.h | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'drivers/resctrl/mpam_internal.h') diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h index 12f0a5b7f39e..12ce80bc7ff7 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -91,7 +91,10 @@ struct mpam_msc { */ struct mutex part_sel_lock; - /* cfg_lock protects the msc configuration. */ + /* + * cfg_lock protects the msc configuration and guards against mbwu_state + * save and restore racing. + */ struct mutex cfg_lock; /* @@ -202,6 +205,19 @@ struct mon_cfg { enum mon_filter_options opts; }; +/* Changes to msmon_mbwu_state are protected by the msc's mon_sel_lock. */ +struct msmon_mbwu_state { + bool enabled; + struct mon_cfg cfg; + + /* + * The value to add to the new reading to account for power management. + */ + u64 correction; + + struct mpam_garbage garbage; +}; + struct mpam_class { /* mpam_components in this class */ struct list_head components; @@ -295,6 +311,9 @@ struct mpam_msc_ris { /* parent: */ struct mpam_vmsc *vmsc; + /* msmon mbwu configuration is preserved over reset */ + struct msmon_mbwu_state *mbwu_state; + struct mpam_garbage garbage; }; -- cgit v1.2.3