[PATCH v4 04/24] x86/resctrl: Pass the schema in info dir's private pointer

[James Morse]

Many of resctrl's per-schema files return a value from struct
rdt_resource, which they take as their 'priv' pointer.

Moving properties that resctrl exposes to user-space into the core
'fs' code, (e.g. the name of the schema), means some of the functions
that back the filesystem need the schema struct (to where the properties
are moved), but currently take struct rdt_resource. For example, once
the CDP resources are merged, struct rdt_resource no longer reflects all
the properties of the schema.
For the info dirs that represent a control, the information needed
will be accessed via struct resctrl_schema, as this is how the resource
is being used. For the monitors, its still struct rdt_resource as the
monitors aren't described as schema.
This difference means the type of the private pointers varies
between control and monitor info dirs.

Change the 'priv' pointer to point to struct resctrl_schema for
the per-schema files that represent a control. The type can be determined
from the fflags field. If the flags are RF_MON_INFO, its a struct
rdt_resource. If the flags are RF_CTRL_INFO, its a struct resctrl_schema.
No entry in res_common_files[] has both flags.

Reviewed-by: Jamie Iles <jamie@xxxxxxxxxxxx>
Signed-off-by: James Morse <james.morse@xxxxxxx>
---
No Changes since v3

Changes since v2:
 * Shuffled commit message,

Changes since v1:
 * Added comment above removed for_each_alloc_enabled_rdt_resource() to hint
   at symmetry.
---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 38 +++++++++++++++++---------
 1 file changed, 25 insertions(+), 13 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 14ea1212f476..6ad9df322282 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -848,7 +848,8 @@ static int rdt_last_cmd_status_show(struct kernfs_open_file *of,
 static int rdt_num_closids_show(struct kernfs_open_file *of,
 				struct seq_file *seq, void *v)
 {
-	struct rdt_resource *r = of->kn->parent->priv;
+	struct resctrl_schema *s = of->kn->parent->priv;
+	struct rdt_resource *r = s->res;
 	struct rdt_hw_resource *hw_res;
 
 	hw_res = resctrl_to_arch_res(r);
@@ -859,7 +860,8 @@ static int rdt_num_closids_show(struct kernfs_open_file *of,
 static int rdt_default_ctrl_show(struct kernfs_open_file *of,
 			     struct seq_file *seq, void *v)
 {
-	struct rdt_resource *r = of->kn->parent->priv;
+	struct resctrl_schema *s = of->kn->parent->priv;
+	struct rdt_resource *r = s->res;
 
 	seq_printf(seq, "%x\n", r->default_ctrl);
 	return 0;
@@ -868,7 +870,8 @@ static int rdt_default_ctrl_show(struct kernfs_open_file *of,
 static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
 			     struct seq_file *seq, void *v)
 {
-	struct rdt_resource *r = of->kn->parent->priv;
+	struct resctrl_schema *s = of->kn->parent->priv;
+	struct rdt_resource *r = s->res;
 
 	seq_printf(seq, "%u\n", r->cache.min_cbm_bits);
 	return 0;
@@ -877,7 +880,8 @@ static int rdt_min_cbm_bits_show(struct kernfs_open_file *of,
 static int rdt_shareable_bits_show(struct kernfs_open_file *of,
 				   struct seq_file *seq, void *v)
 {
-	struct rdt_resource *r = of->kn->parent->priv;
+	struct resctrl_schema *s = of->kn->parent->priv;
+	struct rdt_resource *r = s->res;
 
 	seq_printf(seq, "%x\n", r->cache.shareable_bits);
 	return 0;
@@ -900,13 +904,14 @@ static int rdt_shareable_bits_show(struct kernfs_open_file *of,
 static int rdt_bit_usage_show(struct kernfs_open_file *of,
 			      struct seq_file *seq, void *v)
 {
-	struct rdt_resource *r = of->kn->parent->priv;
+	struct resctrl_schema *s = of->kn->parent->priv;
 	/*
 	 * Use unsigned long even though only 32 bits are used to ensure
 	 * test_bit() is used safely.
 	 */
 	unsigned long sw_shareable = 0, hw_shareable = 0;
 	unsigned long exclusive = 0, pseudo_locked = 0;
+	struct rdt_resource *r = s->res;
 	struct rdt_domain *dom;
 	int i, hwb, swb, excl, psl;
 	enum rdtgrp_mode mode;
@@ -978,7 +983,8 @@ static int rdt_bit_usage_show(struct kernfs_open_file *of,
 static int rdt_min_bw_show(struct kernfs_open_file *of,
 			     struct seq_file *seq, void *v)
 {
-	struct rdt_resource *r = of->kn->parent->priv;
+	struct resctrl_schema *s = of->kn->parent->priv;
+	struct rdt_resource *r = s->res;
 
 	seq_printf(seq, "%u\n", r->membw.min_bw);
 	return 0;
@@ -1009,7 +1015,8 @@ static int rdt_mon_features_show(struct kernfs_open_file *of,
 static int rdt_bw_gran_show(struct kernfs_open_file *of,
 			     struct seq_file *seq, void *v)
 {
-	struct rdt_resource *r = of->kn->parent->priv;
+	struct resctrl_schema *s = of->kn->parent->priv;
+	struct rdt_resource *r = s->res;
 
 	seq_printf(seq, "%u\n", r->membw.bw_gran);
 	return 0;
@@ -1018,7 +1025,8 @@ static int rdt_bw_gran_show(struct kernfs_open_file *of,
 static int rdt_delay_linear_show(struct kernfs_open_file *of,
 			     struct seq_file *seq, void *v)
 {
-	struct rdt_resource *r = of->kn->parent->priv;
+	struct resctrl_schema *s = of->kn->parent->priv;
+	struct rdt_resource *r = s->res;
 
 	seq_printf(seq, "%u\n", r->membw.delay_linear);
 	return 0;
@@ -1038,7 +1046,8 @@ static int max_threshold_occ_show(struct kernfs_open_file *of,
 static int rdt_thread_throttle_mode_show(struct kernfs_open_file *of,
 					 struct seq_file *seq, void *v)
 {
-	struct rdt_resource *r = of->kn->parent->priv;
+	struct resctrl_schema *s = of->kn->parent->priv;
+	struct rdt_resource *r = s->res;
 
 	if (r->membw.throttle_mode == THREAD_THROTTLE_PER_THREAD)
 		seq_puts(seq, "per-thread\n");
@@ -1771,14 +1780,14 @@ int rdtgroup_kn_mode_restore(struct rdtgroup *r, const char *name,
 	return ret;
 }
 
-static int rdtgroup_mkdir_info_resdir(struct rdt_resource *r, char *name,
+static int rdtgroup_mkdir_info_resdir(void *priv, char *name,
 				      unsigned long fflags)
 {
 	struct kernfs_node *kn_subdir;
 	int ret;
 
 	kn_subdir = kernfs_create_dir(kn_info, name,
-				      kn_info->mode, r);
+				      kn_info->mode, priv);
 	if (IS_ERR(kn_subdir))
 		return PTR_ERR(kn_subdir);
 
@@ -1795,6 +1804,7 @@ static int rdtgroup_mkdir_info_resdir(struct rdt_resource *r, char *name,
 
 static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
 {
+	struct resctrl_schema *s;
 	struct rdt_resource *r;
 	unsigned long fflags;
 	char name[32];
@@ -1809,9 +1819,11 @@ static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn)
 	if (ret)
 		goto out_destroy;
 
-	for_each_alloc_enabled_rdt_resource(r) {
+	/* loop over enabled controls, these are all alloc_enabled */
+	list_for_each_entry(s, &resctrl_schema_all, list) {
+		r = s->res;
 		fflags =  r->fflags | RF_CTRL_INFO;
-		ret = rdtgroup_mkdir_info_resdir(r, r->name, fflags);
+		ret = rdtgroup_mkdir_info_resdir(s, r->name, fflags);
 		if (ret)
 			goto out_destroy;
 	}
-- 
2.30.2