From 21690934d93408bb7247943f886b960cf30ecd19 Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@suse.de>
Date: Sat, 22 Nov 2014 11:22:35 +0100
Subject: EDAC, mce_amd_inj: Enable direct writes to MCE MSRs

Normally, writing those causes a #GP but HWCR[McStatusWrEn] controls
that. Provide a knob.

Signed-off-by: Borislav Petkov <bp@suse.de>

diff --git a/drivers/edac/mce_amd_inj.c b/drivers/edac/mce_amd_inj.c
index 9b5023d..9b5ca92 100644
--- a/drivers/edac/mce_amd_inj.c
+++ b/drivers/edac/mce_amd_inj.c
@@ -55,6 +55,30 @@ DEFINE_SIMPLE_ATTRIBUTE(misc_fops, inj_misc_get, inj_misc_set, "%llx\n");
 DEFINE_SIMPLE_ATTRIBUTE(addr_fops, inj_addr_get, inj_addr_set, "%llx\n");
 
 /*
+ * Caller needs to be make sure this cpu doesn't disappear
+ * from under us, i.e.: get_cpu/put_cpu.
+ */
+static int toggle_hw_mce_inject(unsigned int cpu, bool enable)
+{
+	u32 l, h;
+	int err;
+
+	err = rdmsr_on_cpu(cpu, MSR_K7_HWCR, &l, &h);
+	if (err) {
+		pr_err("%s: error reading HWCR\n", __func__);
+		return err;
+	}
+
+	enable ? (l |= BIT(18)) : (l &= ~BIT(18));
+
+	err = wrmsr_on_cpu(cpu, MSR_K7_HWCR, l, h);
+	if (err)
+		pr_err("%s: error writing HWCR\n", __func__);
+
+	return err;
+}
+
+/*
  * This denotes into which bank we're injecting and triggers
  * the injection, at the same time.
  */
-- 
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