[PATCH 26/32] x86/intel_rdt_rdtgroup.c: Create info directory

[Fenghua Yu]

From: Fenghua Yu <fenghua.yu@xxxxxxxxx>

During boot time, the "info" directory is set up under rscctrl root.
it contains one "info" file and one resource specific directory
if the resource is enabled.

If L3 is enabled, "l3" sub-directory is created under the "info"
directory. There are three l3 specific info files under it:
max_closid, max_cbm_len, and domain_to_cache_id.

The "info" directory is exposed to user after rscctrl is mounted.

Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
---
 arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 259 +++++++++++++++++++++++++++++++
 1 file changed, 259 insertions(+)

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index e1936d2..b2140a8 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -238,6 +238,179 @@ static int get_shared_domain(int domain, int level)
 
 	return -1;
 }
+static void rdt_info_show_cat(struct seq_file *seq, int level)
+{
+	int domain;
+	int domain_num = get_domain_num(level);
+	int closid;
+	u64 cbm;
+	struct clos_cbm_table **cctable;
+	int maxid;
+	int shared_domain;
+	int cnt;
+
+	if (level == CACHE_LEVEL3)
+		cctable = l3_cctable;
+	else
+		return;
+
+	maxid = cconfig.max_closid;
+	for (domain = 0; domain < domain_num; domain++) {
+		seq_printf(seq, "domain %d:\n", domain);
+		shared_domain = get_shared_domain(domain, level);
+		for (closid = 0; closid < maxid; closid++) {
+			int dindex, iindex;
+
+			if (test_bit(closid,
+			(unsigned long *)cconfig.closmap[shared_domain])) {
+				dindex = get_dcbm_table_index(closid);
+				cbm = cctable[domain][dindex].cbm;
+				cnt = cctable[domain][dindex].clos_refcnt;
+				seq_printf(seq, "cbm[%d]=%lx, refcnt=%d\n",
+					 dindex, (unsigned long)cbm, cnt);
+				if (cdp_enabled) {
+					iindex = get_icbm_table_index(closid);
+					cbm = cctable[domain][iindex].cbm;
+					cnt =
+					   cctable[domain][iindex].clos_refcnt;
+					seq_printf(seq,
+						   "cbm[%d]=%lx, refcnt=%d\n",
+						   iindex, (unsigned long)cbm,
+						   cnt);
+				}
+			} else {
+				cbm = max_cbm(level);
+				cnt = 0;
+				dindex = get_dcbm_table_index(closid);
+				seq_printf(seq, "cbm[%d]=%lx, refcnt=%d\n",
+					 dindex, (unsigned long)cbm, cnt);
+				if (cdp_enabled) {
+					iindex = get_icbm_table_index(closid);
+					seq_printf(seq,
+						 "cbm[%d]=%lx, refcnt=%d\n",
+						 iindex, (unsigned long)cbm,
+						 cnt);
+				}
+			}
+		}
+	}
+}
+
+static void show_shared_domain(struct seq_file *seq)
+{
+	int domain;
+
+	seq_puts(seq, "Shared domains:\n");
+
+	for_each_cache_domain(domain, 0, shared_domain_num) {
+		struct shared_domain *sd;
+
+		sd = &shared_domain[domain];
+		seq_printf(seq, "domain[%d]:", domain);
+		if (cat_enabled(CACHE_LEVEL3))
+			seq_printf(seq, "l3_domain=%d ", sd->l3_domain);
+		seq_printf(seq, "cpumask=%*pb\n",
+			   cpumask_pr_args(&sd->cpumask));
+	}
+}
+
+static int rdt_info_show(struct seq_file *seq, void *v)
+{
+	show_shared_domain(seq);
+
+	if (cat_l3_enabled) {
+		if (rdt_opts.verbose)
+			rdt_info_show_cat(seq, CACHE_LEVEL3);
+	}
+
+	seq_puts(seq, "\n");
+
+	return 0;
+}
+
+static int res_type_to_level(enum resource_type res_type, int *level)
+{
+	int ret = 0;
+
+	switch (res_type) {
+	case RESOURCE_L3:
+		*level = CACHE_LEVEL3;
+		break;
+	case RESOURCE_NUM:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static int domain_to_cache_id_show(struct seq_file *seq, void *v)
+{
+	struct kernfs_open_file *of = seq->private;
+	enum resource_type res_type;
+	int domain;
+	int leaf;
+	int level = 0;
+	int ret;
+
+	res_type = (enum resource_type)of->kn->parent->priv;
+
+	ret = res_type_to_level(res_type, &level);
+	if (ret)
+		return 0;
+
+	leaf =	get_cache_leaf(level, 0);
+
+	for (domain = 0; domain < get_domain_num(level); domain++) {
+		unsigned int cid;
+
+		cid = cache_domains[leaf].shared_cache_id[domain];
+		seq_printf(seq, "%d:%d\n", domain, cid);
+	}
+
+	return 0;
+}
+
+static struct rftype info_files[] = {
+	{
+		.name = "info",
+		.seq_show = rdt_info_show,
+	},
+	{ }	/* terminate */
+};
+
+/* rdtgroup information files for one cache resource. */
+static struct rftype res_info_files[] = {
+	{
+		.name = "max_closid",
+		.seq_show = rdt_max_closid_show,
+	},
+	{
+		.name = "max_cbm_len",
+		.seq_show = rdt_max_cbm_len_show,
+	},
+	{
+		.name = "domain_to_cache_id",
+		.seq_show = domain_to_cache_id_show,
+	},
+	{ }	/* terminate */
+};
+
+static int info_populate_dir(struct kernfs_node *kn)
+{
+	struct rftype *rfts;
+
+	rfts = info_files;
+	return rdtgroup_addrm_files(kn, rfts, true);
+}
+
+static int res_info_populate_dir(struct kernfs_node *kn)
+{
+	struct rftype *rfts;
+
+	rfts = res_info_files;
+	return rdtgroup_addrm_files(kn, rfts, true);
+}
 
 static int rdtgroup_populate_dir(struct kernfs_node *kn)
 {
@@ -377,6 +550,90 @@ static char *res_info_dir_name(enum resource_type res_type, char *name)
 	return name;
 }
 
+static int create_res_info(enum resource_type res_type,
+			   struct kernfs_node *parent_kn)
+{
+	struct kernfs_node *kn;
+	char name[RDTGROUP_FILE_NAME_MAX];
+	int ret;
+
+	res_info_dir_name(res_type, name);
+	kn = kernfs_create_dir(parent_kn, name, parent_kn->mode, NULL);
+	if (IS_ERR(kn)) {
+		ret = PTR_ERR(kn);
+		goto out;
+	}
+
+	/*
+	 * This extra ref will be put in kernfs_remove() and guarantees
+	 * that @rdtgrp->kn is always accessible.
+	 */
+	kernfs_get(kn);
+
+	ret = rdtgroup_kn_set_ugid(kn);
+	if (ret)
+		goto out_destroy;
+
+	ret = res_info_populate_dir(kn);
+	if (ret)
+		goto out_destroy;
+
+	kernfs_activate(kn);
+
+	ret = 0;
+	goto out;
+
+out_destroy:
+	kernfs_remove(kn);
+out:
+	return ret;
+
+}
+
+static int rdtgroup_create_info_dir(struct kernfs_node *parent_kn,
+				    const char *name)
+{
+	struct kernfs_node *kn;
+	int ret;
+
+	if (parent_kn != root_rdtgrp->kn)
+		return -EPERM;
+
+	/* create the directory */
+	kn = kernfs_create_dir(parent_kn, "info", parent_kn->mode, root_rdtgrp);
+	if (IS_ERR(kn)) {
+		ret = PTR_ERR(kn);
+		goto out;
+	}
+
+	ret = info_populate_dir(kn);
+	if (ret)
+		goto out_destroy;
+
+	if (cat_enabled(CACHE_LEVEL3))
+		create_res_info(RESOURCE_L3, kn);
+
+	/*
+	 * This extra ref will be put in kernfs_remove() and guarantees
+	 * that @rdtgrp->kn is always accessible.
+	 */
+	kernfs_get(kn);
+
+	ret = rdtgroup_kn_set_ugid(kn);
+	if (ret)
+		goto out_destroy;
+
+	kernfs_activate(kn);
+
+	ret = 0;
+	goto out;
+
+out_destroy:
+	kernfs_remove(kn);
+out:
+	return ret;
+}
+
 static int rdtgroup_setup_root(struct rdtgroup_root *root,
 			       unsigned long ss_mask)
 {
@@ -411,6 +668,8 @@ static int rdtgroup_setup_root(struct rdtgroup_root *root,
 	if (ret)
 		goto destroy_root;
 
+	rdtgroup_create_info_dir(root->kf_root->kn, "info_dir");
+
 	/*
 	 * Link the root rdtgroup in this hierarchy into all the css_set
 	 * objects.
-- 
2.5.0