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From:   Fenghua Yu <fenghua.yu@intel.com>
To:     "Thomas Gleixner" <tglx@linutronix.de>,
        "Ingo Molnar" <mingo@redhat.com>, "H Peter Anvin" <hpa@zytor.com>,
        "Tony Luck" <tony.luck@intel.com>
Cc:     "Chatre, Reinette" <reinette.chatre@intel.com>,
        "Xiaochen Shen" <xiaochen.shen@intel.com>,
        "Chen Yu" <yu.c.chen@intel.com>,
        "linux-kernel" <linux-kernel@vger.kernel.org>,
        "x86" <x86@kernel.org>, "Fenghua Yu" <fenghua.yu@intel.com>
Subject: [PATCH 6/9] x86/intel_rdt: Do not allow pseudo-locking of MBA resource
Date:   Fri, 14 Sep 2018 13:32:06 -0700
Message-Id: <1536957129-70380-7-git-send-email-fenghua.yu@intel.com>
In-Reply-To: <1536957129-70380-1-git-send-email-fenghua.yu@intel.com>
References: <1536957129-70380-1-git-send-email-fenghua.yu@intel.com>
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From: Reinette Chatre <reinette.chatre@intel.com>

A system supporting pseudo-locking may have MBA as well as CAT
resources of which only the CAT resources could support cache
pseudo-locking. When the schemata to be pseudo-locked is provided it
should be checked that that schemata does not attempt to pseudo-lock a
MBA resource.

Fixes: e0bdfe8e3 ("x86/intel_rdt: Support creation/removal of pseudo-locked region")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
index d427c86e7cd0..44b7a689d083 100644
--- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -200,6 +200,12 @@ static int parse_line(char *line, struct rdt_resource *r,
 	struct rdt_domain *d;
 	unsigned long dom_id;
 
+	if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
+	    r->rid == RDT_RESOURCE_MBA) {
+		rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n");
+		return -EINVAL;
+	}
+
 next:
 	if (!line || line[0] == '\0')
 		return 0;
-- 
2.19.0