[OpenBIOS] [PATCHv2 10/11] SPARC64: point __context to saved context during CIF calls

[Mark Cave-Ayland]

This will enable Forth executed in CIF calls to be able to modify its
own context and return.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland at ilande.co.uk>
---
 arch/sparc64/call-client.S |   15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/sparc64/call-client.S b/arch/sparc64/call-client.S
index 5b5cae2..ebab6b9 100644
--- a/arch/sparc64/call-client.S
+++ b/arch/sparc64/call-client.S
@@ -14,6 +14,8 @@
 	.data
 	.align	8
 
+client_context:
+	.xword	0
 client_stack:
 	.xword	0
 client_tba:
@@ -84,6 +86,13 @@ sparc64_of_client_interface:
 	
 	RESET_CPU_WINDOW_STATE(cif)
 	
+	/* Update __context to point to saved area */
+	setx	__context, %g6, %g7
+	ldx	[%g7], %g3
+	setx	client_context, %g4, %g5
+	stx	%g3, [%g5]
+	stx	%g1, [%g7]
+	
 	/* Move to OpenBIOS context stack */
 	setx	_fcstack_ptr, %g6, %g7
 	ldx	[%g7], %g6
@@ -109,6 +118,12 @@ sparc64_of_client_interface:
 	/* Return value */
 	stx	%o0, [%g1 + 0x70]
 	
+	/* Restore __context */
+	setx	client_context, %g4, %g5
+	ldx	[%g5], %g3
+	setx	__context, %g6, %g7
+	stx	%g3, [%g7]
+	
 	RESTORE_CPU_STATE(cif)
 	
 	add	%g1, CONTEXT_STATE_SIZE, %g5
-- 
1.7.10.4