From: Max Filippov <jcmvbkbc@gmail.com>
Date: Mon, 4 Aug 2014 01:55:53 +0000 (+0400)
Subject: xtensa: allow single-stepping through unaligned load/store
X-Git-Tag: v4.14-rc1~6277^2~9^2~3
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a83b02e9bd0c28d27b6c6e5b184585f7a1b8bf86;p=platform%2Fkernel%2Flinux-rpi.git

xtensa: allow single-stepping through unaligned load/store

Update icount when icountlevel is non-zero but not greater than EXCM level
when load/store instruction is successfully emulated. This allows
single-stepping over such instruction in userspace debugger.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---

diff --git a/arch/xtensa/kernel/align.S b/arch/xtensa/kernel/align.S
index 87d80d8..890004a 100644
--- a/arch/xtensa/kernel/align.S
+++ b/arch/xtensa/kernel/align.S
@@ -421,6 +421,14 @@ ENTRY(fast_unaligned)
 
 1:	wsr	a7, epc1		# skip emulated instruction
 
+	/* Update icount if we're single-stepping in userspace. */
+	rsr	a4, icountlevel
+	beqz	a4, 1f
+	bgeui	a4, LOCKLEVEL + 1, 1f
+	rsr	a4, icount
+	addi	a4, a4, 1
+	wsr	a4, icount
+1:
 	movi	a4, 0
 	rsr	a3, excsave1
 	s32i	a4, a3, EXC_TABLE_FIXUP