[MIPS] MT: Improved multithreading support.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/include/asm-mips/mipsregs.h b/include/asm-mips/mipsregs.h
index e85a42e..a2ef579 100644
--- a/include/asm-mips/mipsregs.h
+++ b/include/asm-mips/mipsregs.h
@@ -861,7 +861,19 @@
#define write_c0_compare3(val) __write_32bit_c0_register($11, 7, val)
#define read_c0_status() __read_32bit_c0_register($12, 0)
+#ifdef CONFIG_MIPS_MT_SMTC
+#define write_c0_status(val) \
+do { \
+ __write_32bit_c0_register($12, 0, val); \
+ __ehb(); \
+} while (0)
+#else
+/*
+ * Legacy non-SMTC code, which may be hazardous
+ * but which might not support EHB
+ */
#define write_c0_status(val) __write_32bit_c0_register($12, 0, val)
+#endif /* CONFIG_MIPS_MT_SMTC */
#define read_c0_cause() __read_32bit_c0_register($13, 0)
#define write_c0_cause(val) __write_32bit_c0_register($13, 0, val)
@@ -1004,6 +1016,9 @@
#define read_c0_taglo() __read_32bit_c0_register($28, 0)
#define write_c0_taglo(val) __write_32bit_c0_register($28, 0, val)
+#define read_c0_dtaglo() __read_32bit_c0_register($28, 2)
+#define write_c0_dtaglo(val) __write_32bit_c0_register($28, 2, val)
+
#define read_c0_taghi() __read_32bit_c0_register($29, 0)
#define write_c0_taghi(val) __write_32bit_c0_register($29, 0, val)
@@ -1357,6 +1372,11 @@
/*
* Manipulate bits in a c0 register.
*/
+#ifndef CONFIG_MIPS_MT_SMTC
+/*
+ * SMTC Linux requires shutting-down microthread scheduling
+ * during CP0 register read-modify-write sequences.
+ */
#define __BUILD_SET_C0(name) \
static inline unsigned int \
set_c0_##name(unsigned int set) \
@@ -1395,6 +1415,119 @@
return res; \
}
+#else /* SMTC versions that manage MT scheduling */
+
+#include <asm/interrupt.h>
+
+/*
+ * This is a duplicate of dmt() in mipsmtregs.h to avoid problems with
+ * header file recursion.
+ */
+static inline unsigned int __dmt(void)
+{
+ int res;
+
+ __asm__ __volatile__(
+ " .set push \n"
+ " .set mips32r2 \n"
+ " .set noat \n"
+ " .word 0x41610BC1 # dmt $1 \n"
+ " ehb \n"
+ " move %0, $1 \n"
+ " .set pop \n"
+ : "=r" (res));
+
+ instruction_hazard();
+
+ return res;
+}
+
+#define __VPECONTROL_TE_SHIFT 15
+#define __VPECONTROL_TE (1UL << __VPECONTROL_TE_SHIFT)
+
+#define __EMT_ENABLE __VPECONTROL_TE
+
+static inline void __emt(unsigned int previous)
+{
+ if ((previous & __EMT_ENABLE))
+ __asm__ __volatile__(
+ " .set noreorder \n"
+ " .set mips32r2 \n"
+ " .word 0x41600be1 # emt \n"
+ " ehb \n"
+ " .set mips0 \n"
+ " .set reorder \n");
+}
+
+static inline void __ehb(void)
+{
+ __asm__ __volatile__(
+ " ehb \n");
+}
+
+/*
+ * Note that local_irq_save/restore affect TC-specific IXMT state,
+ * not Status.IE as in non-SMTC kernel.
+ */
+
+#define __BUILD_SET_C0(name) \
+static inline unsigned int \
+set_c0_##name(unsigned int set) \
+{ \
+ unsigned int res; \
+ unsigned int omt; \
+ unsigned int flags; \
+ \
+ local_irq_save(flags); \
+ omt = __dmt(); \
+ res = read_c0_##name(); \
+ res |= set; \
+ write_c0_##name(res); \
+ __emt(omt); \
+ local_irq_restore(flags); \
+ \
+ return res; \
+} \
+ \
+static inline unsigned int \
+clear_c0_##name(unsigned int clear) \
+{ \
+ unsigned int res; \
+ unsigned int omt; \
+ unsigned int flags; \
+ \
+ local_irq_save(flags); \
+ omt = __dmt(); \
+ res = read_c0_##name(); \
+ res &= ~clear; \
+ write_c0_##name(res); \
+ __emt(omt); \
+ local_irq_restore(flags); \
+ \
+ return res; \
+} \
+ \
+static inline unsigned int \
+change_c0_##name(unsigned int change, unsigned int new) \
+{ \
+ unsigned int res; \
+ unsigned int omt; \
+ unsigned int flags; \
+ \
+ local_irq_save(flags); \
+ \
+ omt = __dmt(); \
+ res = read_c0_##name(); \
+ res &= ~change; \
+ res |= (new & change); \
+ write_c0_##name(res); \
+ __emt(omt); \
+ local_irq_restore(flags); \
+ \
+ return res; \
+}
+#endif
+
__BUILD_SET_C0(status)
__BUILD_SET_C0(cause)
__BUILD_SET_C0(config)