Commit df5f3a1d authored by Babu Moger's avatar Babu Moger Committed by Borislav Petkov (AMD)
Browse files

x86/resctrl: Unwind properly from rdt_enable_ctx() 



rdt_enable_ctx() enables the features provided during resctrl mount.

Additions to rdt_enable_ctx() are required to also modify error paths
of rdt_enable_ctx() callers to ensure correct unwinding if errors
are encountered after calling rdt_enable_ctx(). This is error prone.

Introduce rdt_disable_ctx() to refactor the error unwinding of
rdt_enable_ctx() to simplify future additions. This also simplifies
cleanup in rdt_kill_sb().

Suggested-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Signed-off-by: default avatarBabu Moger <babu.moger@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarPeter Newman <peternewman@google.com>
Reviewed-by: default avatarTan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: default avatarPeter Newman <peternewman@google.com>
Tested-by: default avatarTan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-5-babu.moger@amd.com
parent d4159243

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

+32 −21
Original line number Diff line number Diff line
@@ -2308,14 +2308,6 @@ int resctrl_arch_set_cdp_enabled(enum resctrl_res_level l, bool enable) 
	return 0;

}



static void cdp_disable_all(void)

{

	if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L3))

		resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);

	if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2))

		resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);

}



/*

 * We don't allow rdtgroup directories to be created anywhere

 * except the root directory. Thus when looking for the rdtgroup
@@ -2395,19 +2387,42 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn, 
			     struct rdtgroup *prgrp,

			     struct kernfs_node **mon_data_kn);



static void rdt_disable_ctx(void)

{

	resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);

	resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);

	set_mba_sc(false);

}



static int rdt_enable_ctx(struct rdt_fs_context *ctx)

{

	int ret = 0;



	if (ctx->enable_cdpl2)

	if (ctx->enable_cdpl2) {

		ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, true);

		if (ret)

			goto out_done;

	}



	if (!ret && ctx->enable_cdpl3)

	if (ctx->enable_cdpl3) {

		ret = resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, true);

		if (ret)

			goto out_cdpl2;

	}



	if (!ret && ctx->enable_mba_mbps)

	if (ctx->enable_mba_mbps) {

		ret = set_mba_sc(true);

		if (ret)

			goto out_cdpl3;

	}



	return 0;



out_cdpl3:

	resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L3, false);

out_cdpl2:

	resctrl_arch_set_cdp_enabled(RDT_RESOURCE_L2, false);

out_done:

	return ret;

}
@@ -2515,13 +2530,13 @@ static int rdt_get_tree(struct fs_context *fc) 
	}



	ret = rdt_enable_ctx(ctx);

	if (ret < 0)

		goto out_cdp;

	if (ret)

		goto out;



	ret = schemata_list_create();

	if (ret) {

		schemata_list_destroy();

		goto out_mba;

		goto out_ctx;

	}



	closid_init();
@@ -2580,11 +2595,8 @@ static int rdt_get_tree(struct fs_context *fc) 
	kernfs_remove(kn_info);

out_schemata_free:

	schemata_list_destroy();

out_mba:

	if (ctx->enable_mba_mbps)

		set_mba_sc(false);

out_cdp:

	cdp_disable_all();

out_ctx:

	rdt_disable_ctx();

out:

	rdt_last_cmd_clear();

	mutex_unlock(&rdtgroup_mutex);
@@ -2816,12 +2828,11 @@ static void rdt_kill_sb(struct super_block *sb) 
	cpus_read_lock();

	mutex_lock(&rdtgroup_mutex);



	set_mba_sc(false);

	rdt_disable_ctx();



	/*Put everything back to default values. */

	for_each_alloc_capable_rdt_resource(r)

		reset_all_ctrls(r);

	cdp_disable_all();

	rmdir_all_sub();

	rdt_pseudo_lock_release();

	rdtgroup_default.mode = RDT_MODE_SHAREABLE;