[PATCH v6 19/24] x86/resctrl: Apply offset correction when config is staged

From: James Morse
Date: Thu Jul 15 2021 - 13:31:54 EST


When resctrl comes to copy the CAT MSR values from the ctrl_val[] array
into hardware, it applies an offset adjustment based on the type of the
resource. CODE and DATA resources have their closid mapped into an
odd/even range. This mapping is based on a property of the resource.

This happens once the new control value has been written to the ctrl_val[]
array. Once the CDP resources are merged, there will only be a single
property that needs to cover both odd/even mappings to the single
ctrl_val[] array. The offset adjustment must be applied before the new
value is written to the array.

Move the logic from cat_wrmsr() to resctrl_arch_update_domains().
The value provided to apply_config() is now an index in the array,
not the closid. The parameters provided via struct msr_param are now
indexes too. As resctrl's use of closid is a u32, struct msr_param's
type is changed to match.
With this, the CODE and DATA resources only use the odd or even
indexes in the array. This allows the temporary num_closid/2 fixes in
domain_setup_ctrlval() and reset_all_ctrls() to be removed.

Reviewed-by: Jamie Iles <jamie@xxxxxxxxxxxx>
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Tested-by: Babu Moger <babu.moger@xxxxxxx>
Signed-off-by: James Morse <james.morse@xxxxxxx>
---
Changes since v3:
* Fixed a fat-fingered 'unsinged u32' - oops!
* Fixed a spelling mistake.

Changes since v2:
* Shuffled commit message,

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 | 32 +++++++++++++++++------
arch/x86/kernel/cpu/resctrl/internal.h | 4 +--
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 7 -----
4 files changed, 27 insertions(+), 31 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 9f8be5ee5e8a..990e41661b4a 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_NONE)
- 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 9ead0c0bf6ee..fdb0e11a78dc 100644
--- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
+++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c
@@ -246,17 +246,29 @@ 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 u32 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->d_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)
@@ -269,11 +281,12 @@ int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid)
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.low = cbm_idx(r, closid);
msr_param.high = msr_param.low + 1;
msr_param.res = r;

@@ -285,7 +298,9 @@ 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;
}
}

@@ -405,11 +420,12 @@ 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 d89c251d7b5a..0260b1a63b86 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -332,8 +332,8 @@ 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 299af12c9fe4..1f72517057e8 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2378,13 +2378,6 @@ 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
--
2.30.2