1 files changed, 65 insertions, 0 deletions
diff --git a/drivers/cxl/core/mce.c b/drivers/cxl/core/mce.c
new file mode 100644
index 000000000000..ff8d078c6ca1
--- /dev/null
+++ b/drivers/cxl/core/mce.c
@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright(c) 2024 Intel Corporation. All rights reserved. */
+#include <linux/mm.h>
+#include <linux/notifier.h>
+#include <linux/set_memory.h>
+#include <asm/mce.h>
+#include <cxlmem.h>
+#include "mce.h"
+
+static int cxl_handle_mce(struct notifier_block *nb, unsigned long val,
+			  void *data)
+{
+	struct cxl_memdev_state *mds = container_of(nb, struct cxl_memdev_state,
+						    mce_notifier);
+	struct cxl_memdev *cxlmd = mds->cxlds.cxlmd;
+	struct cxl_port *endpoint = cxlmd->endpoint;
+	struct mce *mce = data;
+	u64 spa, spa_alias;
+	unsigned long pfn;
+
+	if (!mce || !mce_usable_address(mce))
+		return NOTIFY_DONE;
+
+	if (!endpoint)
+		return NOTIFY_DONE;
+
+	spa = mce->addr & MCI_ADDR_PHYSADDR;
+
+	pfn = spa >> PAGE_SHIFT;
+	if (!pfn_valid(pfn))
+		return NOTIFY_DONE;
+
+	spa_alias = cxl_port_get_spa_cache_alias(endpoint, spa);
+	if (spa_alias == ~0ULL)
+		return NOTIFY_DONE;
+
+	pfn = spa_alias >> PAGE_SHIFT;
+
+	/*
+	 * Take down the aliased memory page. The original memory page flagged
+	 * by the MCE will be taken cared of by the standard MCE handler.
+	 */
+	dev_emerg(mds->cxlds.dev, "Offlining aliased SPA address0: %#llx\n",
+		  spa_alias);
+	if (!memory_failure(pfn, 0))
+		set_mce_nospec(pfn);
+
+	return NOTIFY_OK;
+}
+
+static void cxl_unregister_mce_notifier(void *mce_notifier)
+{
+	mce_unregister_decode_chain(mce_notifier);
+}
+
+int devm_cxl_register_mce_notifier(struct device *dev,
+				   struct notifier_block *mce_notifier)
+{
+	mce_notifier->notifier_call = cxl_handle_mce;
+	mce_notifier->priority = MCE_PRIO_UC;
+	mce_register_decode_chain(mce_notifier);
+
+	return devm_add_action_or_reset(dev, cxl_unregister_mce_notifier,
+					mce_notifier);
+}