A recent attempt to restrict the use of rfi to 64bit cpus in qemu
broke 32bit OpenBIOS when run under a 970.
This is adding a dynamic check on the pvr to choose between rfi and
rfid. Only the 970 family is supported.
Signed-off-by: Cédric Le Goater <clg(a)kaod.org>
---
Tested on qemu.
arch/ppc/qemu/start.S | 25 +++++++++++++++++++++++--
arch/ppc/start.S | 25 +++++++++++++++++++++++--
2 files changed, 46 insertions(+), 4 deletions(-)
Index: openbios.git/arch/ppc/qemu/start.S
===================================================================
--- openbios.git.orig/arch/ppc/qemu/start.S
+++ openbios.git/arch/ppc/qemu/start.S
@@ -27,6 +27,27 @@
#ifdef CONFIG_PPC_64BITSUPPORT
+/* When running on ppc64, we cannot use rfi anymore. Let's try to
+ * catch which cpu we are running on and act accordingly. This is
+ * for 970s only.
+ */
+.macro do_rfi
+ mtsprg1 r3
+ mfpvr r3
+ rlwinm r3,r3,16,16,31
+ cmplwi cr1,r3,0x0039 /* 970 CPUs */
+ beq- cr1,0f
+ cmplwi cr1,r3,0x003C /* 970fx CPUs */
+ beq- cr1,0f
+ cmplwi cr1,r3,0x0044 /* 970mp CPUs */
+ beq- cr1,0f
+ mfsprg1 r3
+ rfi
+0:
+ mfsprg1 r3
+ rfid
+.endm
+
/* We're trying to use the same code for the ppc32 and ppc64 handlers here.
* On ppc32 we only save/restore the registers, C considers volatile.
*
@@ -148,7 +169,7 @@
ll r31,(35 * ULONG_SIZE)(r1) ; \
.endif ; \
ll r1,(1 * ULONG_SIZE)(r1) ; /* restore stack at last */ \
- rfi
+ do_rfi
// PPC32
@@ -319,7 +340,7 @@ VECTOR( 0x800, "FPU" ):
ori r3,r3,0x2000
mtsrr1 r3
mfsprg1 r3
- RFI
+ do_rfi
ILLEGAL_VECTOR( 0x900 )
ILLEGAL_VECTOR( 0xa00 )
Index: openbios.git/arch/ppc/start.S
===================================================================
--- openbios.git.orig/arch/ppc/start.S
+++ openbios.git/arch/ppc/start.S
@@ -25,6 +25,27 @@
#define ILLEGAL_VECTOR( v ) .org __vectors + v ; bl trap_error ;
#define VECTOR( v, dummystr ) .org __vectors + v ; vector__##v
+/* When running on ppc64, we cannot use rfi anymore. Let's try to
+ * catch which cpu we are running on and act accordingly. This is
+ * for 970s only.
+ */
+.macro do_rfi
+ mtsprg1 r3
+ mfpvr r3
+ rlwinm r3,r3,16,16,31
+ cmplwi cr1,r3,0x0039 /* 970 CPUs */
+ beq- cr1,0f
+ cmplwi cr1,r3,0x003C /* 970fx CPUs */
+ beq- cr1,0f
+ cmplwi cr1,r3,0x0044 /* 970mp CPUs */
+ beq- cr1,0f
+ mfsprg1 r3
+ rfi
+0:
+ mfsprg1 r3
+ rfid
+.endm
+
#define EXCEPTION_PREAMBLE \
mtsprg1 r1 ; /* scratch */ \
mfsprg0 r1 ; /* exception stack in sprg0 */ \
@@ -252,7 +273,7 @@ exception_return:
lwz r11,44(r1)
lwz r12,48(r1)
lwz r1,4(r1) // restore r1
- rfi
+ do_rfi
trap_error:
mflr r3
@@ -287,7 +308,7 @@ VECTOR( 0x800, "FPU" ):
ori r3,r3,0x2000
mtsrr1 r3
mfsprg1 r3
- rfi
+ do_rfi
ILLEGAL_VECTOR( 0x900 )
ILLEGAL_VECTOR( 0xa00 )