x86/resctrl: Split struct rdt_resource

resctrl is the defacto Linux ABI for SoC resource partitioning features.

To support it on another architecture, it needs to be abstracted from
the features provided by Intel RDT and AMD PQoS, and moved to /fs/.
struct rdt_resource contains a mix of architecture private details
and properties of the filesystem interface user-space uses.

Start by splitting struct rdt_resource, into an architecture private
'hw' struct, which contains the common resctrl structure that would be
used by any architecture. The foreach helpers are most commonly used by
the filesystem code, and should return the common resctrl structure.
for_each_rdt_resource() is changed to walk the common structure in its
parent arch private structure.

Move as much of the structure as possible into the common structure
in the core code's header file. The x86 hardware accessors remain
part of the architecture private code, as do num_closid, mon_scale
and mbm_width.

mon_scale and mbm_width are used to detect overflow of the hardware
counters, and convert them from their native size to bytes. Any
cross-architecture abstraction should be in terms of bytes, making
these properties private.

The hardware's num_closid is kept in the private structure to force the
filesystem code to use a helper to access it. MPAM would return a single
value for the system, regardless of the resource. Using the helper
prevents this field from being confused with the version of num_closid
that is being exposed to user-space (added in a later patch).

After this split, filesystem code touching a 'hw' struct indicates
where an abstraction is needed.

Splitting this structure only moves types around, and should not lead
to any change in behaviour.

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/20210728170637.25610-2-james.morse@arm.com

1 files changed, 18 insertions, 14 deletions

diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index f07c10b87a87..5daf5847ff4c 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -174,7 +174,7 @@ void __check_limbo(struct rdt_domain *d, bool force_free)
 	struct rdt_resource *r;
 	u32 crmid = 1, nrmid;
 
-	r = &rdt_resources_all[RDT_RESOURCE_L3];
+	r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
 
 	/*
 	 * Skip RMID 0 and start from RMID 1 and check all the RMIDs that
@@ -232,7 +232,7 @@ static void add_rmid_to_limbo(struct rmid_entry *entry)
 	int cpu;
 	u64 val;
 
-	r = &rdt_resources_all[RDT_RESOURCE_L3];
+	r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
 
 	entry->busy = 0;
 	cpu = get_cpu();
@@ -287,6 +287,7 @@ static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int width)
 
 static int __mon_event_count(u32 rmid, struct rmid_read *rr)
 {
+	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(rr->r);
 	struct mbm_state *m;
 	u64 chunks, tval;
 
@@ -319,7 +320,7 @@ static int __mon_event_count(u32 rmid, struct rmid_read *rr)
 		return 0;
 	}
 
-	chunks = mbm_overflow_count(m->prev_msr, tval, rr->r->mbm_width);
+	chunks = mbm_overflow_count(m->prev_msr, tval, hw_res->mbm_width);
 	m->chunks += chunks;
 	m->prev_msr = tval;
 
@@ -334,7 +335,7 @@ static int __mon_event_count(u32 rmid, struct rmid_read *rr)
  */
 static void mbm_bw_count(u32 rmid, struct rmid_read *rr)
 {
-	struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3];
+	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(rr->r);
 	struct mbm_state *m = &rr->d->mbm_local[rmid];
 	u64 tval, cur_bw, chunks;
 
@@ -342,8 +343,8 @@ static void mbm_bw_count(u32 rmid, struct rmid_read *rr)
 	if (tval & (RMID_VAL_ERROR | RMID_VAL_UNAVAIL))
 		return;
 
-	chunks = mbm_overflow_count(m->prev_bw_msr, tval, rr->r->mbm_width);
-	cur_bw = (get_corrected_mbm_count(rmid, chunks) * r->mon_scale) >> 20;
+	chunks = mbm_overflow_count(m->prev_bw_msr, tval, hw_res->mbm_width);
+	cur_bw = (get_corrected_mbm_count(rmid, chunks) * hw_res->mon_scale) >> 20;
 
 	if (m->delta_comp)
 		m->delta_bw = abs(cur_bw - m->prev_bw);
@@ -416,6 +417,7 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm)
 {
 	u32 closid, rmid, cur_msr, cur_msr_val, new_msr_val;
 	struct mbm_state *pmbm_data, *cmbm_data;
+	struct rdt_hw_resource *hw_r_mba;
 	u32 cur_bw, delta_bw, user_bw;
 	struct rdt_resource *r_mba;
 	struct rdt_domain *dom_mba;
@@ -425,7 +427,8 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm)
 	if (!is_mbm_local_enabled())
 		return;
 
-	r_mba = &rdt_resources_all[RDT_RESOURCE_MBA];
+	hw_r_mba = &rdt_resources_all[RDT_RESOURCE_MBA];
+	r_mba = &hw_r_mba->r_resctrl;
 	closid = rgrp->closid;
 	rmid = rgrp->mon.rmid;
 	pmbm_data = &dom_mbm->mbm_local[rmid];
@@ -474,7 +477,7 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct rdt_domain *dom_mbm)
 		return;
 	}
 
-	cur_msr = r_mba->msr_base + closid;
+	cur_msr = hw_r_mba->msr_base + closid;
 	wrmsrl(cur_msr, delay_bw_map(new_msr_val, r_mba));
 	dom_mba->ctrl_val[closid] = new_msr_val;
 
@@ -538,7 +541,7 @@ void cqm_handle_limbo(struct work_struct *work)
 
 	mutex_lock(&rdtgroup_mutex);
 
-	r = &rdt_resources_all[RDT_RESOURCE_L3];
+	r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
 	d = container_of(work, struct rdt_domain, cqm_limbo.work);
 
 	__check_limbo(d, false);
@@ -574,7 +577,7 @@ void mbm_handle_overflow(struct work_struct *work)
 	if (!static_branch_likely(&rdt_mon_enable_key))
 		goto out_unlock;
 
-	r = &rdt_resources_all[RDT_RESOURCE_L3];
+	r = &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl;
 	d = container_of(work, struct rdt_domain, mbm_over.work);
 
 	list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) {
@@ -671,15 +674,16 @@ static void l3_mon_evt_init(struct rdt_resource *r)
 int rdt_get_mon_l3_config(struct rdt_resource *r)
 {
 	unsigned int mbm_offset = boot_cpu_data.x86_cache_mbm_width_offset;
+	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
 	unsigned int cl_size = boot_cpu_data.x86_cache_size;
 	int ret;
 
-	r->mon_scale = boot_cpu_data.x86_cache_occ_scale;
+	hw_res->mon_scale = boot_cpu_data.x86_cache_occ_scale;
 	r->num_rmid = boot_cpu_data.x86_cache_max_rmid + 1;
-	r->mbm_width = MBM_CNTR_WIDTH_BASE;
+	hw_res->mbm_width = MBM_CNTR_WIDTH_BASE;
 
 	if (mbm_offset > 0 && mbm_offset <= MBM_CNTR_WIDTH_OFFSET_MAX)
-		r->mbm_width += mbm_offset;
+		hw_res->mbm_width += mbm_offset;
 	else if (mbm_offset > MBM_CNTR_WIDTH_OFFSET_MAX)
 		pr_warn("Ignoring impossible MBM counter offset\n");
 
@@ -693,7 +697,7 @@ int rdt_get_mon_l3_config(struct rdt_resource *r)
 	resctrl_cqm_threshold = cl_size * 1024 / r->num_rmid;
 
 	/* h/w works in units of "boot_cpu_data.x86_cache_occ_scale" */
-	resctrl_cqm_threshold /= r->mon_scale;
+	resctrl_cqm_threshold /= hw_res->mon_scale;
 
 	ret = dom_data_init(r);
 	if (ret)