[tip: x86/cache] x86/resctrl: Allow update_mba_bw() to update controls directly

From: tip-bot2 for James Morse
Date: Fri Sep 23 2022 - 14:02:53 EST

The following commit has been merged into the x86/cache branch of tip:

Commit-ID: ff6357bb50023af2a1dc8f113930082c5252c753
Gitweb: https://git.kernel.org/tip/ff6357bb50023af2a1dc8f113930082c5252c753
Author: James Morse <james.morse@xxxxxxx>
AuthorDate: Fri, 02 Sep 2022 15:48:19
Committer: Borislav Petkov <bp@xxxxxxx>
CommitterDate: Thu, 22 Sep 2022 17:43:44 +02:00

x86/resctrl: Allow update_mba_bw() to update controls directly

update_mba_bw() calculates a new control value for the MBA resource
based on the user provided mbps_val and the current measured
bandwidth. Some control values need remapping by delay_bw_map().

It does this by calling wrmsrl() directly. This needs splitting
up to be done by an architecture specific helper, so that the
remainder can eventually be moved to /fs/.

Add resctrl_arch_update_one() to apply one configuration value
to the provided resource and domain. This avoids the staging
and cross-calling that is only needed with changes made by
user-space. delay_bw_map() moves to be part of the arch code,
to maintain the 'percentage control' view of MBA resources
in resctrl.

Signed-off-by: James Morse <james.morse@xxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Jamie Iles <quic_jiles@xxxxxxxxxxx>
Reviewed-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxx>
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Tested-by: Xin Hao <xhao@xxxxxxxxxxxxxxxxx>
Tested-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxx>
Tested-by: Cristian Marussi <cristian.marussi@xxxxxxx>
Link: https://lore.kernel.org/r/20220902154829.30399-12-james.morse@xxxxxxx
---
arch/x86/kernel/cpu/resctrl/core.c | 2 +-
arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 21 +++++++++++++++++++++
arch/x86/kernel/cpu/resctrl/internal.h | 1 -
arch/x86/kernel/cpu/resctrl/monitor.c | 13 ++++---------
include/linux/resctrl.h | 8 ++++++++
5 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index f0e2820..90ebb7d 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -296,7 +296,7 @@ mba_wrmsr_amd(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r)
* that can be written to QOS_MSRs.
* There are currently no SKUs which support non linear delay values.
*/
-u32 delay_bw_map(unsigned long bw, struct rdt_resource *r)
+static u32 delay_bw_map(unsigned long bw, struct rdt_resource *r)
{
if (r->membw.delay_linear)
return MAX_MBA_BW - bw;
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index bf9d73c..0ab9232 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -282,6 +282,27 @@ static bool apply_config(struct rdt_hw_domain *hw_dom,
return false;
}

+int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_domain *d,
+ u32 closid, enum resctrl_conf_type t, u32 cfg_val)
+{
+ struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+ struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
+ u32 idx = get_config_index(closid, t);
+ struct msr_param msr_param;
+
+ if (!cpumask_test_cpu(smp_processor_id(), &d->cpu_mask))
+ return -EINVAL;
+
+ hw_dom->ctrl_val[idx] = cfg_val;
+
+ msr_param.res = r;
+ msr_param.low = idx;
+ msr_param.high = idx + 1;
+ hw_res->msr_update(d, &msr_param, r);
+
+ return 0;
+}
+
int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid)
{
struct resctrl_staged_config *cfg;
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 373aaba..3b9e43b 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -527,7 +527,6 @@ void mbm_setup_overflow_handler(struct rdt_domain *dom,
void mbm_handle_overflow(struct work_struct *work);
void __init intel_rdt_mbm_apply_quirk(void);
bool is_mba_sc(struct rdt_resource *r);
-u32 delay_bw_map(unsigned long bw, struct rdt_resource *r);
void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms);
void cqm_handle_limbo(struct work_struct *work);
bool has_busy_rmid(struct rdt_resource *r, struct rdt_domain *d);
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 16028b2..3e69386 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -420,10 +420,8 @@ void mon_event_count(void *info)
*/
static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm)
{
- u32 closid, rmid, cur_msr, cur_msr_val, new_msr_val;
+ u32 closid, rmid, cur_msr_val, new_msr_val;
struct mbm_state *pmbm_data, *cmbm_data;
- struct rdt_hw_resource *hw_r_mba;
- struct rdt_hw_domain *hw_dom_mba;
u32 cur_bw, delta_bw, user_bw;
struct rdt_resource *r_mba;
struct rdt_domain *dom_mba;
@@ -433,8 +431,8 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm)
if (!is_mbm_local_enabled())
return;

- hw_r_mba = &rdt_resources_all[RDT_RESOURCE_MBA];
- r_mba = &hw_r_mba->r_resctrl;
+ r_mba = &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl;
+
closid = rgrp->closid;
rmid = rgrp->mon.rmid;
pmbm_data = &dom_mbm->mbm_local[rmid];
@@ -444,7 +442,6 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm)
pr_warn_once("Failure to get domain for MBA update\n");
return;
}
- hw_dom_mba = resctrl_to_arch_dom(dom_mba);

cur_bw = pmbm_data->prev_bw;
user_bw = dom_mba->mbps_val[closid];
@@ -486,9 +483,7 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm)
return;
}

- cur_msr = hw_r_mba->msr_base + closid;
- wrmsrl(cur_msr, delay_bw_map(new_msr_val, r_mba));
- hw_dom_mba->ctrl_val[closid] = new_msr_val;
+ resctrl_arch_update_one(r_mba, dom_mba, closid, CDP_NONE, new_msr_val);

/*
* Delta values are updated dynamically package wise for each
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 93dfe55..f4c9101 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -197,6 +197,14 @@ struct resctrl_schema {
/* The number of closid supported by this resource regardless of CDP */
u32 resctrl_arch_get_num_closid(struct rdt_resource *r);
int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid);
+
+/*
+ * Update the ctrl_val and apply this config right now.
+ * Must be called on one of the domain's CPUs.
+ */
+int resctrl_arch_update_one(struct rdt_resource *r, struct rdt_domain *d,
+ u32 closid, enum resctrl_conf_type t, u32 cfg_val);
+
u32 resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d,
u32 closid, enum resctrl_conf_type type);
int resctrl_online_domain(struct rdt_resource *r, struct rdt_domain *d);