[PATCH v2 3/6] mm: Add VM_FAULT_ARCH_* codes

[Palmer Dabbelt]

A handful of architectures (arm, s390, and soon RISC-V) define their
own internal fault codes, so instead dedicate a few standard codes as
being architecture-specific to avoid conflicts.

Signed-off-by: Palmer Dabbelt <palmer at rivosinc.com>
---
 include/linux/mm_types.h | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index fd9b863869b4..47f36a2fdaac 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -938,6 +938,7 @@ typedef __bitwise unsigned int vm_fault_t;
  *				in DAX)
  * @VM_FAULT_COMPLETED:		->fault completed, meanwhile mmap lock released
  * @VM_FAULT_HINDEX_MASK:	mask HINDEX value
+ * @VM_FAULT_ARCH_*		Architecture-specific VM fault codes.
  *
  */
 enum vm_fault_reason {
@@ -955,6 +956,11 @@ enum vm_fault_reason {
 	VM_FAULT_NEEDDSYNC      = (__force vm_fault_t)0x0002000,
 	VM_FAULT_COMPLETED      = (__force vm_fault_t)0x0004000,
 	VM_FAULT_HINDEX_MASK    = (__force vm_fault_t)0x00f0000,
+	VM_FAULT_ARCH_0         = (__force vm_fault_t)0x0100000,
+	VM_FAULT_ARCH_1         = (__force vm_fault_t)0x0200000,
+	VM_FAULT_ARCH_2         = (__force vm_fault_t)0x0400000,
+	VM_FAULT_ARCH_3         = (__force vm_fault_t)0x0800000,
+	VM_FAULT_ARCH_4         = (__force vm_fault_t)0x1000000,
 };
 
 /* Encode hstate index for a hwpoisoned large page */
@@ -977,7 +983,12 @@ enum vm_fault_reason {
 	{ VM_FAULT_RETRY,               "RETRY" },	\
 	{ VM_FAULT_FALLBACK,            "FALLBACK" },	\
 	{ VM_FAULT_DONE_COW,            "DONE_COW" },	\
-	{ VM_FAULT_NEEDDSYNC,           "NEEDDSYNC" }
+	{ VM_FAULT_NEEDDSYNC,           "NEEDDSYNC" },  \
+	{ VM_FAULT_ARCH_0,              "ARCH_0" },     \
+	{ VM_FAULT_ARCH_1,              "ARCH_1" },     \
+	{ VM_FAULT_ARCH_2,              "ARCH_2" },     \
+	{ VM_FAULT_ARCH_3,              "ARCH_3" },     \
+	{ VM_FAULT_ARCH_4,              "ARCH_4" },     \
 
 struct vm_special_mapping {
 	const char *name;	/* The name, e.g. "[vdso]". */
-- 
2.39.2