[SPARC64]: Do not call winfix_dax blindly

Verify we really are taking a data access exception trap, at TL1, from
one of the window spill/fill handlers.

Else call a new function, data_access_exception_tl1, to log the error.

Signed-off-by: David S. Miller <[e-mail]>

arch/sparc64/kernel/entry.S

···
 	ldxa		[%g5] ASI_DMMU, %g5	! Get SFAR
 	stxa		%g0, [%g3] ASI_DMMU	! Clear SFSR.FaultValid bit
 	membar		#Sync
+	rdpr		%tt, %g3
+	cmp		%g3, 0x80		! first win spill/fill trap
+	blu,pn		%xcc, 1f
+	 cmp		%g3, 0xff		! last win spill/fill trap
+	bgu,pn		%xcc, 1f
+	 nop
 	ba,pt		%xcc, winfix_dax
 	 rdpr		%tpc, %g3
+1:	sethi		%hi(109f), %g7
+	ba,pt		%xcc, etraptl1
+109:	 or		%g7, %lo(109b), %g7
+	mov		%l4, %o1
+	mov		%l5, %o2
+	call		data_access_exception_tl1
+	 add		%sp, PTREGS_OFF, %o0
+	ba,pt		%xcc, rtrap
+	 clr		%l6
+
 __do_data_access_exception:
 	rdpr		%pstate, %g4
 	wrpr		%g4, PSTATE_MG|PSTATE_AG, %pstate

arch/sparc64/kernel/traps.c

···
 	force_sig_info(SIGSEGV, &info, current);
 }
 
+void data_access_exception_tl1(struct pt_regs *regs,
+			       unsigned long sfsr, unsigned long sfar)
+{
+	if (notify_die(DIE_TRAP_TL1, "data access exception tl1", regs,
+		       0, 0x30, SIGTRAP) == NOTIFY_STOP)
+		return;
+
+	dump_tl1_traplog((struct tl1_traplog *)(regs + 1));
+	data_access_exception(regs, sfsr, sfar);
+}
+
 #ifdef CONFIG_PCI
 /* This is really pathetic... */
 extern volatile int pci_poke_in_progress;