[PATCH 11/13] powerpc: Implement architecture specific KMSAN interface

[Nicholas Miehlbradt]

arch_kmsan_get_meta_or_null finds the metadata addresses for addresses
in the ioremap region which is mapped separately on powerpc.

kmsan_vir_addr_valid is the same as virt_addr_valid except excludes the
check that addr is less than high_memory since this function can be
called on addresses higher than this.

Signed-off-by: Nicholas Miehlbradt <nicholas@xxxxxxxxxxxxx>
---
 arch/powerpc/include/asm/kmsan.h | 44 ++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 arch/powerpc/include/asm/kmsan.h

diff --git a/arch/powerpc/include/asm/kmsan.h b/arch/powerpc/include/asm/kmsan.h
new file mode 100644
index 000000000000..bc84f6ff2ee9
--- /dev/null
+++ b/arch/powerpc/include/asm/kmsan.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * powerpc KMSAN support.
+ *
+ */
+
+#ifndef _ASM_POWERPC_KMSAN_H
+#define _ASM_POWERPC_KMSAN_H
+
+#ifndef __ASSEMBLY__
+#ifndef MODULE
+
+#include <linux/mmzone.h>
+#include <asm/page.h>
+#include <asm/book3s/64/pgtable.h>
+
+/*
+ * Functions below are declared in the header to make sure they are inlined.
+ * They all are called from kmsan_get_metadata() for every memory access in
+ * the kernel, so speed is important here.
+ */
+
+/*
+ * No powerpc specific metadata locations
+ */
+static inline void *arch_kmsan_get_meta_or_null(void *addr, bool is_origin)
+{
+	unsigned long addr64 = (unsigned long)addr, off;
+	if (KERN_IO_START <= addr64 && addr64 < KERN_IO_END) {
+		off = addr64 - KERN_IO_START;
+		return (void *)off + (is_origin ? KERN_IO_ORIGIN_START : KERN_IO_SHADOW_START);
+	} else {
+		return 0;
+	}
+}
+
+static inline bool kmsan_virt_addr_valid(void *addr)
+{
+	return (unsigned long)addr >= PAGE_OFFSET && pfn_valid(virt_to_pfn(addr));
+}
+
+#endif /* !MODULE */
+#endif /* !__ASSEMBLY__ */
+#endif /* _ASM_POWERPC_KMSAN_H */
-- 
2.40.1