efi/arm64: Add debugfs node to dump UEFI runtime page tables

Register the debugfs node 'efi_page_tables' to allow the UEFI runtime
page tables to be inspected. Note that ARM does not have 'asm/ptdump.h'
[yet] so for now, this is arm64 only.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/firmware/efi/arm-runtime.c b/drivers/firmware/efi/arm-runtime.c
index ae001450545f..7c75a8d9091a 100644
--- a/drivers/firmware/efi/arm-runtime.c
+++ b/drivers/firmware/efi/arm-runtime.c
@@ -39,6 +39,26 @@ static struct mm_struct efi_mm = {
         .mmlist                 = LIST_HEAD_INIT(efi_mm.mmlist),
 };
 
+#ifdef CONFIG_ARM64_PTDUMP
+#include <asm/ptdump.h>
+
+static struct ptdump_info efi_ptdump_info = {
+        .mm             = &efi_mm,
+        .markers        = (struct addr_marker[]){
+                { 0,            "UEFI runtime start" },
+                { TASK_SIZE_64, "UEFI runtime end" }
+        },
+        .base_addr      = 0,
+};
+
+static int __init ptdump_init(void)
+{
+        return ptdump_register(&efi_ptdump_info, "efi_page_tables");
+}
+device_initcall(ptdump_init);
+
+#endif
+
 static bool __init efi_virtmap_init(void)
 {
         efi_memory_desc_t *md;