MIPS: Sibyte: Fix M3 TLB exception handler workaround.

commit 3d45285 upstream.

The M3 workaround needs to cmpare the region and VPN2 fields only.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

arch/mips/mm/tlbex.c

@@ -725,10 +725,15 @@ static void __cpuinit build_r4000_tlb_refill_handler(void)
 	 * create the plain linear handler
 	 */
 	if (bcm1250_m3_war()) {
-		UASM_i_MFC0(&p, K0, C0_BADVADDR);
-		UASM_i_MFC0(&p, K1, C0_ENTRYHI);
+		unsigned int segbits = 44;
+
+		uasm_i_dmfc0(&p, K0, C0_BADVADDR);
+		uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
 		uasm_i_xor(&p, K0, K0, K1);
-		UASM_i_SRL(&p, K0, K0, PAGE_SHIFT + 1);
+		uasm_i_dsrl32(&p, K1, K0, 62 - 32);
+		uasm_i_dsrl(&p, K0, K0, 12 + 1);
+		uasm_i_dsll32(&p, K0, K0, 64 + 12 + 1 - segbits - 32);
+		uasm_i_or(&p, K0, K0, K1);
 		uasm_il_bnez(&p, &r, K0, label_leave);
 		/* No need for uasm_i_nop */
 	}
@@ -1242,10 +1247,15 @@ static void __cpuinit build_r4000_tlb_load_handler(void)
 	memset(relocs, 0, sizeof(relocs));
 
 	if (bcm1250_m3_war()) {
-		UASM_i_MFC0(&p, K0, C0_BADVADDR);
-		UASM_i_MFC0(&p, K1, C0_ENTRYHI);
+		unsigned int segbits = 44;
+
+		uasm_i_dmfc0(&p, K0, C0_BADVADDR);
+		uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
 		uasm_i_xor(&p, K0, K0, K1);
-		UASM_i_SRL(&p, K0, K0, PAGE_SHIFT + 1);
+		uasm_i_dsrl32(&p, K1, K0, 62 - 32);
+		uasm_i_dsrl(&p, K0, K0, 12 + 1);
+		uasm_i_dsll32(&p, K0, K0, 64 + 12 + 1 - segbits - 32);
+		uasm_i_or(&p, K0, K0, K1);
 		uasm_il_bnez(&p, &r, K0, label_leave);
 		/* No need for uasm_i_nop */
 	}