[MIPS] MT: Improved multithreading support.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S
index d2afbd1..0b1b54a 100644
--- a/arch/mips/kernel/r4k_switch.S
+++ b/arch/mips/kernel/r4k_switch.S
@@ -88,7 +88,18 @@
PTR_ADDIU t0, $28, _THREAD_SIZE - 32
set_saved_sp t0, t1, t2
-
+#ifdef CONFIG_MIPS_MT_SMTC
+ /* Read-modify-writes of Status must be atomic on a VPE */
+ mfc0 t2, CP0_TCSTATUS
+ ori t1, t2, TCSTATUS_IXMT
+ mtc0 t1, CP0_TCSTATUS
+ andi t2, t2, TCSTATUS_IXMT
+ ehb
+ DMT 8 # dmt t0
+ move t1,ra
+ jal mips_ihb
+ move ra,t1
+#endif /* CONFIG_MIPS_MT_SMTC */
mfc0 t1, CP0_STATUS /* Do we really need this? */
li a3, 0xff01
and t1, a3
@@ -97,6 +108,18 @@
and a2, a3
or a2, t1
mtc0 a2, CP0_STATUS
+#ifdef CONFIG_MIPS_MT_SMTC
+ ehb
+ andi t0, t0, VPECONTROL_TE
+ beqz t0, 1f
+ emt
+1:
+ mfc0 t1, CP0_TCSTATUS
+ xori t1, t1, TCSTATUS_IXMT
+ or t1, t1, t2
+ mtc0 t1, CP0_TCSTATUS
+ ehb
+#endif /* CONFIG_MIPS_MT_SMTC */
move v0, a0
jr ra
END(resume)
@@ -131,10 +154,19 @@
#define FPU_DEFAULT 0x00000000
LEAF(_init_fpu)
+#ifdef CONFIG_MIPS_MT_SMTC
+ /* Rather than manipulate per-VPE Status, set per-TC bit in TCStatus */
+ mfc0 t0, CP0_TCSTATUS
+ /* Bit position is the same for Status, TCStatus */
+ li t1, ST0_CU1
+ or t0, t1
+ mtc0 t0, CP0_TCSTATUS
+#else /* Normal MIPS CU1 enable */
mfc0 t0, CP0_STATUS
li t1, ST0_CU1
or t0, t1
mtc0 t0, CP0_STATUS
+#endif /* CONFIG_MIPS_MT_SMTC */
fpu_enable_hazard
li t1, FPU_DEFAULT