sh: Disable SCIF2 on the SH-X3 proto CPU.

SCIF2 and the FPU exceptions happen to share vector numbers, one in
EXPEVT and the other in INTEVT. This is a violation of the interface and
should have never made it in to silicon. On top of that, the demux hack
that was added for special dispatch is rather error prone, and introduces
more problems than it solves. Kill all of it off, and just refuse to deal
with SCIF2 outright.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/cpu/sh3/entry.S

@@ -297,41 +297,8 @@ ENTRY(vbr_base)
 !
 	.balign 	256,0,256
 general_exception:
-#ifndef CONFIG_CPU_SUBTYPE_SHX3
 	bra	handle_exception
 	 sts	pr, k3		! save original pr value in k3
-#else
-	mov.l	1f, k4
-	mov.l	@k4, k4
-
-	! Is EXPEVT larger than 0x800?
-	mov	#0x8, k0
-	shll8	k0
-	cmp/hs	k0, k4
-	bf	0f
-
-	! then add 0x580 (k2 is 0xd80 or 0xda0)
-	mov	#0x58, k0
-	shll2	k0
-	shll2	k0
-	add	k0, k4
-0:
-	! Setup stack and save DSP context (k0 contains original r15 on return)
-	bsr	prepare_stack
-	 nop
-
-	! Save registers / Switch to bank 0
-	mov		k4, k2		! keep vector in k2
-	mov.l	1f, k4		! SR bits to clear in k4
-	bsr	save_regs	! needs original pr value in k3
-	 nop
-
-	bra	handle_exception_special
-	 nop
-
-	.align	2
-1:	.long	EXPEVT
-#endif
 
 ! prepare_stack()
 ! - roll back gRB

arch/sh/kernel/cpu/sh4a/setup-shx3.c

@@ -15,6 +15,15 @@
 #include <linux/sh_timer.h>
 #include <asm/mmzone.h>
 
+/*
+ * This intentionally only registers SCIF ports 0, 1, and 3. SCIF 2
+ * INTEVT values overlap with the FPU EXPEVT ones, requiring special
+ * demuxing in the exception dispatch path.
+ *
+ * As this overlap is something that never should have made it in to
+ * silicon in the first place, we just refuse to deal with the port at
+ * all rather than adding infrastructure to hack around it.
+ */
 static struct plat_sci_port sci_platform_data[] = {
 	{
 		.mapbase	= 0xffc30000,
@@ -26,11 +35,6 @@ static struct plat_sci_port sci_platform_data[] = {
 		.flags		= UPF_BOOT_AUTOCONF,
 		.type		= PORT_SCIF,
 		.irqs		= { 44, 45, 47, 46 },
-	}, {
-		.mapbase	= 0xffc50000,
-		.flags		= UPF_BOOT_AUTOCONF,
-		.type		= PORT_SCIF,
-		.irqs		= { 48, 49, 51, 50 },
 	}, {
 		.mapbase	= 0xffc60000,
 		.flags		= UPF_BOOT_AUTOCONF,
@@ -313,8 +317,6 @@ static struct intc_vect vectors[] __initdata = {
 	INTC_VECT(SCIF0_BRI, 0x740), INTC_VECT(SCIF0_TXI, 0x760),
 	INTC_VECT(SCIF1_ERI, 0x780), INTC_VECT(SCIF1_RXI, 0x7a0),
 	INTC_VECT(SCIF1_BRI, 0x7c0), INTC_VECT(SCIF1_TXI, 0x7e0),
-	INTC_VECT(SCIF2_ERI, 0x800), INTC_VECT(SCIF2_RXI, 0x820),
-	INTC_VECT(SCIF2_BRI, 0x840), INTC_VECT(SCIF2_TXI, 0x860),
 	INTC_VECT(SCIF3_ERI, 0x880), INTC_VECT(SCIF3_RXI, 0x8a0),
 	INTC_VECT(SCIF3_BRI, 0x8c0), INTC_VECT(SCIF3_TXI, 0x8e0),
 	INTC_VECT(DMAC0_DMINT0, 0x900), INTC_VECT(DMAC0_DMINT1, 0x920),
@@ -355,7 +357,6 @@ static struct intc_group groups[] __initdata = {
 	INTC_GROUP(PCII56789, PCII5, PCII6, PCII7, PCII8, PCII9),
 	INTC_GROUP(SCIF0, SCIF0_ERI, SCIF0_RXI, SCIF0_BRI, SCIF0_TXI),
 	INTC_GROUP(SCIF1, SCIF1_ERI, SCIF1_RXI, SCIF1_BRI, SCIF1_TXI),
-	INTC_GROUP(SCIF2, SCIF2_ERI, SCIF2_RXI, SCIF2_BRI, SCIF2_TXI),
 	INTC_GROUP(SCIF3, SCIF3_ERI, SCIF3_RXI, SCIF3_BRI, SCIF3_TXI),
 	INTC_GROUP(DMAC0, DMAC0_DMINT0, DMAC0_DMINT1, DMAC0_DMINT2,
 		   DMAC0_DMINT3, DMAC0_DMINT4, DMAC0_DMINT5, DMAC0_DMAE),

arch/sh/kernel/traps_32.c

@@ -945,14 +945,9 @@ void __init trap_init(void)
 	set_exception_table_evt(0x800, do_reserved_inst);
 	set_exception_table_evt(0x820, do_illegal_slot_inst);
 #elif defined(CONFIG_SH_FPU)
-#ifdef CONFIG_CPU_SUBTYPE_SHX3
-	set_exception_table_evt(0xd80, fpu_state_restore_trap_handler);
-	set_exception_table_evt(0xda0, fpu_state_restore_trap_handler);
-#else
 	set_exception_table_evt(0x800, fpu_state_restore_trap_handler);
 	set_exception_table_evt(0x820, fpu_state_restore_trap_handler);
 #endif
-#endif
 
 #ifdef CONFIG_CPU_SH2
 	set_exception_table_vec(TRAP_ADDRESS_ERROR, address_error_trap_handler);