MIPS: Make DIEI support as a config option

DI(Disable Interrupt) and EI(Enable Interrupt) instructions is required by
MIPSR2/MIPSR6, however, it appears to be buggy on some processors such as
Loongson-3A1000. Thus we make it as a config option to allow disable it at
compile time with CPU_MIPSR2 selected.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: chenhc@lemote.com
Cc: paul.burton@mips.com
Cc: linux-kernel@vger.kernel.org

arch/mips/Kconfig

@@ -2084,12 +2084,14 @@ config CPU_MIPSR2
 	bool
 	default y if CPU_MIPS32_R2 || CPU_MIPS64_R2 || CPU_CAVIUM_OCTEON
 	select CPU_HAS_RIXI
+	select CPU_HAS_DIEI if !CPU_DIEI_BROKEN
 	select MIPS_SPRAM
 
 config CPU_MIPSR6
 	bool
 	default y if CPU_MIPS32_R6 || CPU_MIPS64_R6
 	select CPU_HAS_RIXI
+	select CPU_HAS_DIEI if !CPU_DIEI_BROKEN
 	select HAVE_ARCH_BITREVERSE
 	select MIPS_ASID_BITS_VARIABLE
 	select MIPS_CRC_SUPPORT
@@ -2549,6 +2551,13 @@ config CPU_HAS_WB
 config XKS01
 	bool
 
+config CPU_HAS_DIEI
+	depends on !CPU_DIEI_BROKEN
+	bool
+
+config CPU_DIEI_BROKEN
+	bool
+
 config CPU_HAS_RIXI
 	bool
 

arch/mips/include/asm/irqflags.h

@@ -18,7 +18,7 @@
 #include <asm/compiler.h>
 #include <asm/hazards.h>
 
-#if defined(CONFIG_CPU_MIPSR2) || defined (CONFIG_CPU_MIPSR6)
+#if defined(CONFIG_CPU_HAS_DIEI)
 
 static inline void arch_local_irq_disable(void)
 {
@@ -94,7 +94,7 @@ static inline void arch_local_irq_restore(unsigned long flags)
 void arch_local_irq_disable(void);
 unsigned long arch_local_irq_save(void);
 void arch_local_irq_restore(unsigned long flags);
-#endif /* CONFIG_CPU_MIPSR2 || CONFIG_CPU_MIPSR6 */
+#endif /* CONFIG_CPU_HAS_DIEI */
 
 static inline void arch_local_irq_enable(void)
 {
@@ -102,7 +102,7 @@ static inline void arch_local_irq_enable(void)
 	"	.set	push						\n"
 	"	.set	reorder						\n"
 	"	.set	noat						\n"
-#if   defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)
+#if defined(CONFIG_CPU_HAS_DIEI)
 	"	ei							\n"
 #else
 	"	mfc0	$1,$12						\n"

arch/mips/lib/mips-atomic.c

@@ -15,7 +15,7 @@
 #include <linux/export.h>
 #include <linux/stringify.h>
 
-#if !defined(CONFIG_CPU_MIPSR2) && !defined(CONFIG_CPU_MIPSR6)
+#if !defined(CONFIG_CPU_HAS_DIEI)
 
 /*
  * For cli() we have to insert nops to make sure that the new value
@@ -110,4 +110,4 @@ notrace void arch_local_irq_restore(unsigned long flags)
 }
 EXPORT_SYMBOL(arch_local_irq_restore);
 
-#endif /* !CONFIG_CPU_MIPSR2 && !CONFIG_CPU_MIPSR6 */
+#endif /* !CONFIG_CPU_HAS_DIEI */