1 files changed, 218 insertions, 143 deletions

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 8388adf241b2..333c177a2471 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -24,6 +24,7 @@
 #include <linux/cpu.h>
 #include <linux/debugfs.h>
 #include <linux/fs.h>
+#include <linux/fs_parser.h>
 #include <linux/sysfs.h>
 #include <linux/kernfs.h>
 #include <linux/seq_buf.h>
@@ -32,6 +33,7 @@
 #include <linux/sched/task.h>
 #include <linux/slab.h>
 #include <linux/task_work.h>
+#include <linux/user_namespace.h>
 
 #include <uapi/linux/magic.h>
 
@@ -1858,46 +1860,6 @@ static void cdp_disable_all(void)
 		cdpl2_disable();
 }
 
-static int parse_rdtgroupfs_options(char *data)
-{
-	char *token, *o = data;
-	int ret = 0;
-
-	while ((token = strsep(&o, ",")) != NULL) {
-		if (!*token) {
-			ret = -EINVAL;
-			goto out;
-		}
-
-		if (!strcmp(token, "cdp")) {
-			ret = cdpl3_enable();
-			if (ret)
-				goto out;
-		} else if (!strcmp(token, "cdpl2")) {
-			ret = cdpl2_enable();
-			if (ret)
-				goto out;
-		} else if (!strcmp(token, "mba_MBps")) {
-			if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
-				ret = set_mba_sc(true);
-			else
-				ret = -EINVAL;
-			if (ret)
-				goto out;
-		} else {
-			ret = -EINVAL;
-			goto out;
-		}
-	}
-
-	return 0;
-
-out:
-	pr_err("Invalid mount option \"%s\"\n", token);
-
-	return ret;
-}
-
 /*
  * We don't allow rdtgroup directories to be created anywhere
  * except the root directory. Thus when looking for the rdtgroup
@@ -1969,13 +1931,27 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn,
 			     struct rdtgroup *prgrp,
 			     struct kernfs_node **mon_data_kn);
 
-static struct dentry *rdt_mount(struct file_system_type *fs_type,
-				int flags, const char *unused_dev_name,
-				void *data)
+static int rdt_enable_ctx(struct rdt_fs_context *ctx)
 {
+	int ret = 0;
+
+	if (ctx->enable_cdpl2)
+		ret = cdpl2_enable();
+
+	if (!ret && ctx->enable_cdpl3)
+		ret = cdpl3_enable();
+
+	if (!ret && ctx->enable_mba_mbps)
+		ret = set_mba_sc(true);
+
+	return ret;
+}
+
+static int rdt_get_tree(struct fs_context *fc)
+{
+	struct rdt_fs_context *ctx = rdt_fc2context(fc);
 	struct rdt_domain *dom;
 	struct rdt_resource *r;
-	struct dentry *dentry;
 	int ret;
 
 	cpus_read_lock();
@@ -1984,53 +1960,42 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type,
 	 * resctrl file system can only be mounted once.
 	 */
 	if (static_branch_unlikely(&rdt_enable_key)) {
-		dentry = ERR_PTR(-EBUSY);
+		ret = -EBUSY;
 		goto out;
 	}
 
-	ret = parse_rdtgroupfs_options(data);
-	if (ret) {
-		dentry = ERR_PTR(ret);
+	ret = rdt_enable_ctx(ctx);
+	if (ret < 0)
 		goto out_cdp;
-	}
 
 	closid_init();
 
 	ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
-	if (ret) {
-		dentry = ERR_PTR(ret);
-		goto out_cdp;
-	}
+	if (ret < 0)
+		goto out_mba;
 
 	if (rdt_mon_capable) {
 		ret = mongroup_create_dir(rdtgroup_default.kn,
 					  NULL, "mon_groups",
 					  &kn_mongrp);
-		if (ret) {
-			dentry = ERR_PTR(ret);
+		if (ret < 0)
 			goto out_info;
-		}
 		kernfs_get(kn_mongrp);
 
 		ret = mkdir_mondata_all(rdtgroup_default.kn,
 					&rdtgroup_default, &kn_mondata);
-		if (ret) {
-			dentry = ERR_PTR(ret);
+		if (ret < 0)
 			goto out_mongrp;
-		}
 		kernfs_get(kn_mondata);
 		rdtgroup_default.mon.mon_data_kn = kn_mondata;
 	}
 
 	ret = rdt_pseudo_lock_init();
-	if (ret) {
-		dentry = ERR_PTR(ret);
+	if (ret)
 		goto out_mondata;
-	}
 
-	dentry = kernfs_mount(fs_type, flags, rdt_root,
-			      RDTGROUP_SUPER_MAGIC, NULL);
-	if (IS_ERR(dentry))
+	ret = kernfs_get_tree(fc);
+	if (ret < 0)
 		goto out_psl;
 
 	if (rdt_alloc_capable)
@@ -2059,14 +2024,95 @@ out_mongrp:
 		kernfs_remove(kn_mongrp);
 out_info:
 	kernfs_remove(kn_info);
+out_mba:
+	if (ctx->enable_mba_mbps)
+		set_mba_sc(false);
 out_cdp:
 	cdp_disable_all();
 out:
 	rdt_last_cmd_clear();
 	mutex_unlock(&rdtgroup_mutex);
 	cpus_read_unlock();
+	return ret;
+}
+
+enum rdt_param {
+	Opt_cdp,
+	Opt_cdpl2,
+	Opt_mba_mbps,
+	nr__rdt_params
+};
+
+static const struct fs_parameter_spec rdt_param_specs[] = {
+	fsparam_flag("cdp",		Opt_cdp),
+	fsparam_flag("cdpl2",		Opt_cdpl2),
+	fsparam_flag("mba_MBps",	Opt_mba_mbps),
+	{}
+};
+
+static const struct fs_parameter_description rdt_fs_parameters = {
+	.name		= "rdt",
+	.specs		= rdt_param_specs,
+};
+
+static int rdt_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct rdt_fs_context *ctx = rdt_fc2context(fc);
+	struct fs_parse_result result;
+	int opt;
+
+	opt = fs_parse(fc, &rdt_fs_parameters, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case Opt_cdp:
+		ctx->enable_cdpl3 = true;
+		return 0;
+	case Opt_cdpl2:
+		ctx->enable_cdpl2 = true;
+		return 0;
+	case Opt_mba_mbps:
+		if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+			return -EINVAL;
+		ctx->enable_mba_mbps = true;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static void rdt_fs_context_free(struct fs_context *fc)
+{
+	struct rdt_fs_context *ctx = rdt_fc2context(fc);
+
+	kernfs_free_fs_context(fc);
+	kfree(ctx);
+}
+
+static const struct fs_context_operations rdt_fs_context_ops = {
+	.free		= rdt_fs_context_free,
+	.parse_param	= rdt_parse_param,
+	.get_tree	= rdt_get_tree,
+};
 
-	return dentry;
+static int rdt_init_fs_context(struct fs_context *fc)
+{
+	struct rdt_fs_context *ctx;
+
+	ctx = kzalloc(sizeof(struct rdt_fs_context), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->kfc.root = rdt_root;
+	ctx->kfc.magic = RDTGROUP_SUPER_MAGIC;
+	fc->fs_private = &ctx->kfc;
+	fc->ops = &rdt_fs_context_ops;
+	if (fc->user_ns)
+		put_user_ns(fc->user_ns);
+	fc->user_ns = get_user_ns(&init_user_ns);
+	fc->global = true;
+	return 0;
 }
 
 static int reset_all_ctrls(struct rdt_resource *r)
@@ -2239,9 +2285,10 @@ static void rdt_kill_sb(struct super_block *sb)
 }
 
 static struct file_system_type rdt_fs_type = {
-	.name    = "resctrl",
-	.mount   = rdt_mount,
-	.kill_sb = rdt_kill_sb,
+	.name			= "resctrl",
+	.init_fs_context	= rdt_init_fs_context,
+	.parameters		= &rdt_fs_parameters,
+	.kill_sb		= rdt_kill_sb,
 };
 
 static int mon_addfile(struct kernfs_node *parent_kn, const char *name,
@@ -2469,103 +2516,131 @@ static void cbm_ensure_valid(u32 *_val, struct rdt_resource *r)
 	bitmap_clear(val, zero_bit, cbm_len - zero_bit);
 }
 
-/**
- * rdtgroup_init_alloc - Initialize the new RDT group's allocations
- *
- * A new RDT group is being created on an allocation capable (CAT)
- * supporting system. Set this group up to start off with all usable
- * allocations. That is, all shareable and unused bits.
+/*
+ * Initialize cache resources per RDT domain
  *
- * All-zero CBM is invalid. If there are no more shareable bits available
- * on any domain then the entire allocation will fail.
+ * Set the RDT domain up to start off with all usable allocations. That is,
+ * all shareable and unused bits. All-zero CBM is invalid.
  */
-static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
+static int __init_one_rdt_domain(struct rdt_domain *d, struct rdt_resource *r,
+				 u32 closid)
 {
 	struct rdt_resource *r_cdp = NULL;
 	struct rdt_domain *d_cdp = NULL;
 	u32 used_b = 0, unused_b = 0;
-	u32 closid = rdtgrp->closid;
-	struct rdt_resource *r;
 	unsigned long tmp_cbm;
 	enum rdtgrp_mode mode;
-	struct rdt_domain *d;
 	u32 peer_ctl, *ctrl;
-	int i, ret;
+	int i;
 
-	for_each_alloc_enabled_rdt_resource(r) {
-		/*
-		 * Only initialize default allocations for CBM cache
-		 * resources
-		 */
-		if (r->rid == RDT_RESOURCE_MBA)
-			continue;
-		list_for_each_entry(d, &r->domains, list) {
-			rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp);
-			d->have_new_ctrl = false;
-			d->new_ctrl = r->cache.shareable_bits;
-			used_b = r->cache.shareable_bits;
-			ctrl = d->ctrl_val;
-			for (i = 0; i < closids_supported(); i++, ctrl++) {
-				if (closid_allocated(i) && i != closid) {
-					mode = rdtgroup_mode_by_closid(i);
-					if (mode == RDT_MODE_PSEUDO_LOCKSETUP)
-						break;
-					/*
-					 * If CDP is active include peer
-					 * domain's usage to ensure there
-					 * is no overlap with an exclusive
-					 * group.
-					 */
-					if (d_cdp)
-						peer_ctl = d_cdp->ctrl_val[i];
-					else
-						peer_ctl = 0;
-					used_b |= *ctrl | peer_ctl;
-					if (mode == RDT_MODE_SHAREABLE)
-						d->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;
-			/*
-			 * Force the initial CBM to be valid, user can
-			 * modify the CBM based on system availability.
-			 */
-			cbm_ensure_valid(&d->new_ctrl, r);
+	rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp);
+	d->have_new_ctrl = false;
+	d->new_ctrl = r->cache.shareable_bits;
+	used_b = r->cache.shareable_bits;
+	ctrl = d->ctrl_val;
+	for (i = 0; i < closids_supported(); i++, ctrl++) {
+		if (closid_allocated(i) && i != closid) {
+			mode = rdtgroup_mode_by_closid(i);
+			if (mode == RDT_MODE_PSEUDO_LOCKSETUP)
+				break;
 			/*
-			 * Assign the u32 CBM to an unsigned long to ensure
-			 * that bitmap_weight() does not access out-of-bound
-			 * memory.
+			 * If CDP is active include peer domain's
+			 * usage to ensure there is no overlap
+			 * with an exclusive group.
 			 */
-			tmp_cbm = d->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",
-						    r->name, d->id);
-				return -ENOSPC;
-			}
-			d->have_new_ctrl = true;
+			if (d_cdp)
+				peer_ctl = d_cdp->ctrl_val[i];
+			else
+				peer_ctl = 0;
+			used_b |= *ctrl | peer_ctl;
+			if (mode == RDT_MODE_SHAREABLE)
+				d->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;
+	/*
+	 * Force the initial CBM to be valid, user can
+	 * modify the CBM based on system availability.
+	 */
+	cbm_ensure_valid(&d->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;
+	if (bitmap_weight(&tmp_cbm, r->cache.cbm_len) < r->cache.min_cbm_bits) {
+		rdt_last_cmd_printf("No space on %s:%d\n", r->name, d->id);
+		return -ENOSPC;
+	}
+	d->have_new_ctrl = true;
+
+	return 0;
+}
+
+/*
+ * Initialize cache resources with default values.
+ *
+ * A new RDT group is being created on an allocation capable (CAT)
+ * supporting system. Set this group up to start off with all usable
+ * allocations.
+ *
+ * If there are no more shareable bits available on any domain then
+ * the entire allocation will fail.
+ */
+static int rdtgroup_init_cat(struct rdt_resource *r, u32 closid)
+{
+	struct rdt_domain *d;
+	int ret;
+
+	list_for_each_entry(d, &r->domains, list) {
+		ret = __init_one_rdt_domain(d, r, closid);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+/* Initialize MBA resource with default values. */
+static void rdtgroup_init_mba(struct rdt_resource *r)
+{
+	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;
+	}
+}
+
+/* Initialize the RDT group's allocations. */
+static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
+{
+	struct rdt_resource *r;
+	int ret;
 
 	for_each_alloc_enabled_rdt_resource(r) {
-		/*
-		 * Only initialize default allocations for CBM cache
-		 * resources
-		 */
-		if (r->rid == RDT_RESOURCE_MBA)
-			continue;
+		if (r->rid == RDT_RESOURCE_MBA) {
+			rdtgroup_init_mba(r);
+		} else {
+			ret = rdtgroup_init_cat(r, rdtgrp->closid);
+			if (ret < 0)
+				return ret;
+		}
+
 		ret = update_domains(r, rdtgrp->closid);
 		if (ret < 0) {
 			rdt_last_cmd_puts("Failed to initialize allocations\n");
 			return ret;
 		}
-		rdtgrp->mode = RDT_MODE_SHAREABLE;
+
 	}
 
+	rdtgrp->mode = RDT_MODE_SHAREABLE;
+
 	return 0;
 }