LoongArch: Override higher address bits in JUMP_VIRT_ADDR

In JUMP_VIRT_ADDR we are performing an or calculation on address value
directly from pcaddi.

This will only work if we are currently running from direct 1:1 mapping
addresses or firmware's DMW is configured exactly same as kernel. Still,
we should not rely on such assumption.

Fix by overriding higher bits in address comes from pcaddi, so we can
get rid of or operator.

Cc: [email protected]
Signed-off-by: Jiaxun Yang <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>

Author: FlyGoat

arch/loongarch/include/asm/stackframe.h

@@ -42,7 +42,7 @@
 	.macro JUMP_VIRT_ADDR temp1 temp2
 	li.d	\temp1, CACHE_BASE
 	pcaddi	\temp2, 0
-	or	\temp1, \temp1, \temp2
+	bstrins.d  \temp1, \temp2, (DMW_PABITS - 1), 0
 	jirl	zero, \temp1, 0xc
 	.endm