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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2007-12-21 15:39:26 +1100
committerJosh Boyer <jwboyer@linux.vnet.ibm.com>2007-12-23 13:13:03 -0600
commit9dae8afdf212d39bc7c25f1b1ca9b10f10f6beaa (patch)
tree12721945adf3a3fc01ba292e1756af4826a7eed3 /arch/powerpc/kernel/misc_32.S
parent69c0785112921a43739495a68f459fde88a9bbd8 (diff)
downloadlinux-9dae8afdf212d39bc7c25f1b1ca9b10f10f6beaa.tar.gz
[POWERPC] 4xx: Add early udbg support for 40x processors
This adds some basic real mode based early udbg support for 40x
in order to debug things more easily

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Diffstat (limited to 'arch/powerpc/kernel/misc_32.S')
-rw-r--r--arch/powerpc/kernel/misc_32.S39
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index ea1137851a4a..be09f0d2d90b 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -206,6 +206,45 @@ _GLOBAL(_nmask_and_or_msr)
 	isync
 	blr			/* Done */
 
+#ifdef CONFIG_40x
+
+/*
+ * Do an IO access in real mode
+ */
+_GLOBAL(real_readb)
+	mfmsr	r7
+	ori	r0,r7,MSR_DR
+	xori	r0,r0,MSR_DR
+	sync
+	mtmsr	r0
+	sync
+	isync
+	lbz	r3,0(r3)
+	sync
+	mtmsr	r7
+	sync
+	isync
+	blr
+
+	/*
+ * Do an IO access in real mode
+ */
+_GLOBAL(real_writeb)
+	mfmsr	r7
+	ori	r0,r7,MSR_DR
+	xori	r0,r0,MSR_DR
+	sync
+	mtmsr	r0
+	sync
+	isync
+	stb	r3,0(r4)
+	sync
+	mtmsr	r7
+	sync
+	isync
+	blr
+
+#endif /* CONFIG_40x */
 
 /*
  * Flush MMU TLB