x86/resctrl: Group staged configuration into a separate struct

When configuration changes are made, the new value is written to struct
rdt_domain's new_ctrl field and the have_new_ctrl flag is set. Later
new_ctrl is copied to hardware by a call to update_domains().

Once the CDP resources are merged, there will be one new_ctrl field in
use by two struct resctrl_schema requiring a per-schema IPI to copy the
value to hardware.

Move new_ctrl and have_new_ctrl into a new struct resctrl_staged_config.
Before the CDP resources can be merged, struct rdt_domain will need an
array of these, one per type of configuration. Using the type as an
index to the array will ensure that a schema configuration string can't
specify the same domain twice.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jamie Iles <jamie@nuviainc.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lkml.kernel.org/r/20210728170637.25610-14-james.morse@arm.com

1 files changed, 13 insertions, 9 deletions

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 1f8c8d79d00b..62cc82d7b06e 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2752,6 +2752,7 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s,
 				 u32 closid)
 {
 	struct rdt_resource *r_cdp = NULL;
+	struct resctrl_staged_config *cfg;
 	struct rdt_domain *d_cdp = NULL;
 	struct rdt_resource *r = s->res;
 	u32 used_b = 0, unused_b = 0;
@@ -2761,8 +2762,9 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s,
 	int i;
 
 	rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp);
-	d->have_new_ctrl = false;
-	d->new_ctrl = r->cache.shareable_bits;
+	cfg = &d->staged_config;
+	cfg->have_new_ctrl = false;
+	cfg->new_ctrl = r->cache.shareable_bits;
 	used_b = r->cache.shareable_bits;
 	ctrl = resctrl_to_arch_dom(d)->ctrl_val;
 	for (i = 0; i < closids_supported(); i++, ctrl++) {
@@ -2786,29 +2788,29 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s,
 				peer_ctl = 0;
 			used_b |= *ctrl | peer_ctl;
 			if (mode == RDT_MODE_SHAREABLE)
-				d->new_ctrl |= *ctrl | peer_ctl;
+				cfg->new_ctrl |= *ctrl | peer_ctl;
 		}
 	}
 	if (d->plr && d->plr->cbm > 0)
 		used_b |= d->plr->cbm;
 	unused_b = used_b ^ (BIT_MASK(r->cache.cbm_len) - 1);
 	unused_b &= BIT_MASK(r->cache.cbm_len) - 1;
-	d->new_ctrl |= unused_b;
+	cfg->new_ctrl |= unused_b;
 	/*
 	 * Force the initial CBM to be valid, user can
 	 * modify the CBM based on system availability.
 	 */
-	d->new_ctrl = cbm_ensure_valid(d->new_ctrl, r);
+	cfg->new_ctrl = cbm_ensure_valid(cfg->new_ctrl, r);
 	/*
 	 * Assign the u32 CBM to an unsigned long to ensure that
 	 * bitmap_weight() does not access out-of-bound memory.
 	 */
-	tmp_cbm = d->new_ctrl;
+	tmp_cbm = cfg->new_ctrl;
 	if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < r->cache.min_cbm_bits) {
 		rdt_last_cmd_printf("No space on %s:%d\n", s->name, d->id);
 		return -ENOSPC;
 	}
-	d->have_new_ctrl = true;
+	cfg->have_new_ctrl = true;
 
 	return 0;
 }
@@ -2840,11 +2842,13 @@ static int rdtgroup_init_cat(struct resctrl_schema *s, u32 closid)
 /* Initialize MBA resource with default values. */
 static void rdtgroup_init_mba(struct rdt_resource *r)
 {
+	struct resctrl_staged_config *cfg;
 	struct rdt_domain *d;
 
 	list_for_each_entry(d, &r->domains, list) {
-		d->new_ctrl = is_mba_sc(r) ? MBA_MAX_MBPS : r->default_ctrl;
-		d->have_new_ctrl = true;
+		cfg = &d->staged_config;
+		cfg->new_ctrl = is_mba_sc(r) ? MBA_MAX_MBPS : r->default_ctrl;
+		cfg->have_new_ctrl = true;
 	}
 }