commit 2a0b24f56c2492b932f1aed617ae80fb23500d21
author Steven J. Hill <Steven.Hill@imgtec.com> Mon Mar 25 12:15:55 2013 -0500
committer Ralf Baechle <ralf@linux-mips.org> Thu May 09 17:55:18 2013 +0200
tree c9aec2872f912c65b83a92a66fe94f6006427d73
parent 102cedc32a6e3cd537374a3678d407591d5a6fab

MIPS: microMIPS: Add support for exception handling.

All exceptions must be taken in microMIPS mode, never in classic
MIPS mode or the kernel falls apart. A few NOP instructions are
used to maintain the correct alignment of microMIPS versions of
the exception vectors.

Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>

arch/mips/mm/tlbex.c

diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index fb4ca99..0a68f2a 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -2103,6 +2103,13 @@
 
 	uasm_l_nopage_tlbl(&l, p);
 	build_restore_work_registers(&p);
+#ifdef CONFIG_CPU_MICROMIPS
+	if ((unsigned long)tlb_do_page_fault_0 & 1) {
+		uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_0));
+		uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_0));
+		uasm_i_jr(&p, K0);
+	} else
+#endif
 	uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff);
 	uasm_i_nop(&p);
 
@@ -2150,6 +2157,13 @@
 
 	uasm_l_nopage_tlbs(&l, p);
 	build_restore_work_registers(&p);
+#ifdef CONFIG_CPU_MICROMIPS
+	if ((unsigned long)tlb_do_page_fault_1 & 1) {
+		uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1));
+		uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1));
+		uasm_i_jr(&p, K0);
+	} else
+#endif
 	uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
 	uasm_i_nop(&p);
 
@@ -2198,6 +2212,13 @@
 
 	uasm_l_nopage_tlbm(&l, p);
 	build_restore_work_registers(&p);
+#ifdef CONFIG_CPU_MICROMIPS
+	if ((unsigned long)tlb_do_page_fault_1 & 1) {
+		uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_1));
+		uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_1));
+		uasm_i_jr(&p, K0);
+	} else
+#endif
 	uasm_i_j(&p, (unsigned long)tlb_do_page_fault_1 & 0x0fffffff);
 	uasm_i_nop(&p);