x86/resctrl: Group struct rdt_hw_domain cleanup

domain_add_cpu() and domain_remove_cpu() need to kfree() the child
arrays that were allocated by domain_setup_ctrlval().

As this memory is moved around, and new arrays are created, adjusting
the error handling cleanup code becomes noisier.

To simplify this, move all the kfree() calls into a domain_free() helper.
This depends on struct rdt_hw_domain being kzalloc()d, allowing it to
unconditionally kfree() all the child arrays.
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jamie Iles <quic_jiles@quicinc.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Xin Hao <xhao@linux.alibaba.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20220902154829.30399-5-james.morse@arm.com

arch/x86/kernel/cpu/resctrl/core.c

@@ -414,6 +414,13 @@ void setup_default_ctrlval(struct rdt_resource *r, u32 *dc, u32 *dm)
 	}
 }
 
+static void domain_free(struct rdt_hw_domain *hw_dom)
+{
+	kfree(hw_dom->ctrl_val);
+	kfree(hw_dom->mbps_val);
+	kfree(hw_dom);
+}
+
 static int domain_setup_ctrlval(struct rdt_resource *r, struct rdt_domain *d)
 {
 	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
@@ -488,7 +495,7 @@ static void domain_add_cpu(int cpu, struct rdt_resource *r)
 	rdt_domain_reconfigure_cdp(r);
 
 	if (r->alloc_capable && domain_setup_ctrlval(r, d)) {
-		kfree(hw_dom);
+		domain_free(hw_dom);
 		return;
 	}
 
@@ -497,9 +504,7 @@ static void domain_add_cpu(int cpu, struct rdt_resource *r)
 	err = resctrl_online_domain(r, d);
 	if (err) {
 		list_del(&d->list);
-		kfree(hw_dom->ctrl_val);
-		kfree(hw_dom->mbps_val);
-		kfree(hw_dom);
+		domain_free(hw_dom);
 	}
 }
 
@@ -547,12 +552,10 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r)
 		if (d->plr)
 			d->plr->d = NULL;
 
-		kfree(hw_dom->ctrl_val);
-		kfree(hw_dom->mbps_val);
 		bitmap_free(d->rmid_busy_llc);
 		kfree(d->mbm_total);
 		kfree(d->mbm_local);
-		kfree(hw_dom);
+		domain_free(hw_dom);
 		return;
 	}