[PATCH v2 20/24] x86/resctrl: Apply offset correction when config is staged

[James Morse <james.morse@arm.com>]

When resctrl comes to write the CAT MSR values, it applies an
adjustment based on the style of the resource. CODE and DATA
resources have their closid mapped into an odd/even range. Previously
this decision was based on the resource.

Move this logic to apply_config() so that in future it can
be based on the style of the configuration, not the resource.

This makes it possible to merge the resources.

Once the resources are merged, there may be multiple configurations
to apply for a single closid and resource. resctrl_arch_update_domains()
should supply the low and high indexes based on the changes it has made
to the ctrl_val array as this allows the hardware to be updated once for
a set of changes.

Reviewed-by: Jamie Iles <jamie@nuviainc.com>
Signed-off-by: James Morse <james.morse@arm.com>
---
Changes since v1:
 * Removing the patch that moved the closid to the staged config means the
   min/max and return from apply_config() appears here.
---
 arch/x86/kernel/cpu/resctrl/core.c        | 15 +-------
 arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 44 ++++++++++++++++++-----
 arch/x86/kernel/cpu/resctrl/internal.h    |  4 +--
 arch/x86/kernel/cpu/resctrl/rdtgroup.c    |  7 ----
 4 files changed, 38 insertions(+), 32 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index f1d0d64e5d97..cb3186bc248b 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -195,11 +195,6 @@ struct rdt_hw_resource rdt_resources_all[] = {
 	},
 };
 
-static unsigned int cbm_idx(struct rdt_resource *r, unsigned int closid)
-{
-	return closid * r->cache.cbm_idx_mult + r->cache.cbm_idx_offset;
-}
-
 /*
  * cache_alloc_hsw_probe() - Have to probe for Intel haswell server CPUs
  * as they do not have CPUID enumeration support for Cache allocation.
@@ -438,7 +433,7 @@ cat_wrmsr(struct rdt_domain *d, struct msr_param *m, struct rdt_resource *r)
 	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
 
 	for (i = m->low; i < m->high; i++)
-		wrmsrl(hw_res->msr_base + cbm_idx(r, i), hw_dom->ctrl_val[i]);
+		wrmsrl(hw_res->msr_base + i, hw_dom->ctrl_val[i]);
 }
 
 struct rdt_domain *get_domain_from_cpu(int cpu, struct rdt_resource *r)
@@ -549,14 +544,6 @@ static int domain_setup_ctrlval(struct rdt_resource *r, struct rdt_domain *d)
 
 	m.low = 0;
 	m.high = hw_res->num_closid;
-
-	/*
-	 * temporary: the array is full-size, but cat_wrmsr() still re-maps
-	 * the index.
-	 */
-	if (hw_res->conf_type != CDP_BOTH)
-		m.high /= 2;
-
 	hw_res->msr_update(d, &m, r);
 	return 0;
 }
diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
index 72a8cf52de47..12a898d42689 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -246,35 +246,47 @@ static int parse_line(char *line, struct resctrl_schema *s,
 	return -EINVAL;
 }
 
-static void apply_config(struct rdt_hw_domain *hw_dom,
-			 struct resctrl_staged_config *cfg, int closid,
+static unsigned int cbm_idx(struct rdt_resource *r, unsigned int closid)
+{
+	if (r->rid == RDT_RESOURCE_MBA)
+		return closid;
+
+	return closid * r->cache.cbm_idx_mult + r->cache.cbm_idx_offset;
+}
+
+static bool apply_config(struct rdt_hw_domain *hw_dom,
+			 struct resctrl_staged_config *cfg, u32 idx,
 			 cpumask_var_t cpu_mask, bool mba_sc)
 {
 	struct rdt_domain *dom = &hw_dom->resctrl;
 	u32 *dc = !mba_sc ? hw_dom->ctrl_val : hw_dom->mbps_val;
 
-	if (cfg->new_ctrl != dc[closid]) {
+	if (cfg->new_ctrl != dc[idx]) {
 		cpumask_set_cpu(cpumask_any(&dom->cpu_mask), cpu_mask);
-		dc[closid] = cfg->new_ctrl;
+		dc[idx] = cfg->new_ctrl;
+
+		return true;
 	}
+
+	return false;
 }
 
 int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid)
 {
 	struct resctrl_staged_config *cfg;
 	struct rdt_hw_domain *hw_dom;
+	bool msr_param_init = false;
 	struct msr_param msr_param;
 	enum resctrl_conf_type t;
 	cpumask_var_t cpu_mask;
 	struct rdt_domain *d;
 	bool mba_sc;
 	int cpu;
+	u32 idx;
 
 	if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
 		return -ENOMEM;
 
-	msr_param.low = closid;
-	msr_param.high = msr_param.low + 1;
 	msr_param.res = r;
 
 	mba_sc = is_mba_sc(r);
@@ -285,10 +297,23 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid)
 			if (!cfg->have_new_ctrl)
 				continue;
 
-			apply_config(hw_dom, cfg, closid, cpu_mask, mba_sc);
+			idx = cbm_idx(r, closid);
+			if (!apply_config(hw_dom, cfg, idx, cpu_mask, mba_sc))
+				continue;
+
+			if (!msr_param_init) {
+				msr_param.low = idx;
+				msr_param.high = idx;
+				msr_param_init = true;
+			} else {
+				msr_param.low = min(msr_param.low, idx);
+				msr_param.high = max(msr_param.high, idx);
+			}
 		}
 	}
 
+	msr_param.high =+ 1;
+
 	/*
 	 * Avoid writing the control msr with control values when
 	 * MBA software controller is enabled
@@ -405,11 +430,12 @@ void resctrl_arch_get_config(struct rdt_resource *r, struct rdt_domain *d,
 			     u32 closid, enum resctrl_conf_type type, u32 *value)
 {
 	struct rdt_hw_domain *hw_dom = resctrl_to_arch_dom(d);
+	u32 idx = cbm_idx(r, closid);
 
 	if (!is_mba_sc(r))
-		*value = hw_dom->ctrl_val[closid];
+		*value = hw_dom->ctrl_val[idx];
 	else
-		*value = hw_dom->mbps_val[closid];
+		*value = hw_dom->mbps_val[idx];
 }
 
 static void show_doms(struct seq_file *s, struct resctrl_schema *schema, int closid)
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 9bafe3b32035..ac36249f43ba 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -324,8 +324,8 @@ static inline struct rdt_hw_domain *resctrl_to_arch_dom(struct rdt_domain *r)
  */
 struct msr_param {
 	struct rdt_resource	*res;
-	int			low;
-	int			high;
+	u32			low;
+	u32			high;
 };
 
 static inline bool is_llc_occupancy_enabled(void)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index a3e5c8b1b0cb..801bff59db06 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2368,13 +2368,6 @@ static int reset_all_ctrls(struct rdt_resource *r)
 	msr_param.low = 0;
 	msr_param.high = hw_res->num_closid;
 
-	/*
-	 * temporary: the array is full-sized, but cat_wrmsr() still re-maps
-	 * the index.
-	 */
-	if (hw_res->cdp_enabled)
-		msr_param.high /= 2;
-
 	/*
 	 * Disable resource control for this resource by setting all
 	 * CBMs in all domains to the maximum mask value. Pick one CPU
-- 
2.30.0