MN10300: Make various interrupt priority settings configurable

Make the settings of interrupt priorities used by various services configurable
at run time.

Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: Kiyoshi Owada <owada.kiyoshi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>

2 files changed, 76 insertions, 6 deletions

diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig
index a1f334ce0a36..a0a16e6e4a4e 100644
--- a/arch/mn10300/Kconfig
+++ b/arch/mn10300/Kconfig
@@ -351,6 +351,80 @@ config MN10300_TTYSM2_CTS
 
 endmenu
 
+menu "Interrupt request priority options"
+
+comment "[!] NOTE: A lower number/level indicates a higher priority (0 is highest, 6 is lowest)"
+
+comment "____Non-maskable interrupt levels____"
+comment "The following must be set to a higher priority than local_irq_disable() and on-chip serial"
+
+config GDBSTUB_IRQ_LEVEL
+        int "GDBSTUB interrupt priority"
+        depends on GDBSTUB
+        range 0 1 if LINUX_CLI_LEVEL = 2
+        range 0 2 if LINUX_CLI_LEVEL = 3
+        range 0 3 if LINUX_CLI_LEVEL = 4
+        range 0 4 if LINUX_CLI_LEVEL = 5
+        range 0 5 if LINUX_CLI_LEVEL = 6
+        default 0
+
+comment "The following must be set to a higher priority than local_irq_disable()"
+
+config MN10300_SERIAL_IRQ_LEVEL
+        int "MN10300 on-chip serial interrupt priority"
+        depends on MN10300_TTYSM
+        range 1 1 if LINUX_CLI_LEVEL = 2
+        range 1 2 if LINUX_CLI_LEVEL = 3
+        range 1 3 if LINUX_CLI_LEVEL = 4
+        range 1 4 if LINUX_CLI_LEVEL = 5
+        range 1 5 if LINUX_CLI_LEVEL = 6
+        default 1
+
+comment "-"
+comment "____Maskable interrupt levels____"
+
+config LINUX_CLI_LEVEL
+        int "The highest interrupt priority excluded by local_irq_disable() (2-6)"
+        range 2 6
+        default 2
+        help
+          local_irq_disable() doesn't actually disable maskable interrupts -
+          what it does is restrict the levels of interrupt which are permitted
+          (a lower level indicates a higher priority) by lowering the value in
+          EPSW.IM from 7.  Any interrupt is permitted for which the level is
+          lower than EPSW.IM.
+
+          Certain interrupts, such as GDBSTUB and virtual MN10300 on-chip
+          serial DMA interrupts are allowed to interrupt normal disabled
+          sections.
+
+comment "The following must be set to a equal to or lower priority than LINUX_CLI_LEVEL"
+
+config TIMER_IRQ_LEVEL
+        int "Kernel timer interrupt priority"
+        range LINUX_CLI_LEVEL 6
+        default 4
+
+config PCI_IRQ_LEVEL
+        int "PCI interrupt priority"
+        depends on PCI
+        range LINUX_CLI_LEVEL 6
+        default 5
+
+config ETHERNET_IRQ_LEVEL
+        int "Ethernet interrupt priority"
+        depends on SMC91X || SMC911X || SMSC911X
+        range LINUX_CLI_LEVEL 6
+        default 6
+
+config EXT_SERIAL_IRQ_LEVEL
+        int "External serial port interrupt priority"
+        depends on SERIAL_8250
+        range LINUX_CLI_LEVEL 6
+        default 6
+
+endmenu
+
 source "mm/Kconfig"
 
 menu "Power management options"
diff --git a/arch/mn10300/include/asm/irqflags.h b/arch/mn10300/include/asm/irqflags.h
index f1b64b256060..b3ab2071354d 100644
--- a/arch/mn10300/include/asm/irqflags.h
+++ b/arch/mn10300/include/asm/irqflags.h
@@ -23,11 +23,7 @@
  *   - level 6 - timer interrupt
  * - "enabled":  run in IM7
  */
-#ifdef CONFIG_MN10300_TTYSM
-#define MN10300_CLI_LEVEL       EPSW_IM_2
-#else
-#define MN10300_CLI_LEVEL       EPSW_IM_1
-#endif
+#define MN10300_CLI_LEVEL       (CONFIG_LINUX_CLI_LEVEL << EPSW_IM_SHIFT)
 
 #ifndef __ASSEMBLY__
 
@@ -94,7 +90,7 @@ static inline void arch_local_irq_restore(unsigned long flags)
 
 static inline bool arch_irqs_disabled_flags(unsigned long flags)
 {
-        return (flags & EPSW_IM) <= MN10300_CLI_LEVEL;
+        return (flags & (EPSW_IE | EPSW_IM)) != (EPSW_IE | EPSW_IM_7);
 }
 
 static inline bool arch_irqs_disabled(void)