Do core interrupt masking in a less general fashion and save some instructions to decrease size and speed things up a little bit. Small fix to a few places where interrupts would get enabled again where they shouldn't have been (context switching calls when disabled).

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@16811 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 19 insertions, 1 deletions

diff --git a/firmware/target/sh/system-target.h b/firmware/target/sh/system-target.h
index 7fb8fecb6b..d641076694 100644
--- a/firmware/target/sh/system-target.h
+++ b/firmware/target/sh/system-target.h
@@ -52,11 +52,29 @@ static inline int set_irq_level(int level)
 {
     int i;
     /* Read the old level and set the new one */
-    asm volatile ("stc sr, %0" : "=r" (i));
+
+    /* Not volatile - will be optimized away if the return value isn't used */
+    asm ("stc sr, %0" : "=r" (i));
     asm volatile ("ldc %0, sr" : : "r" (level));
     return i;
 }
 
+static inline void enable_irq(void)
+{
+    int i;
+    asm volatile ("mov %1, %0 \n" /* Save a constant load from RAM */
+                  "ldc %0, sr \n" : "=&r"(i) : "i"(0));
+}
+
+#define disable_irq() \
+    ((void)set_irq_level(HIGHEST_IRQ_LEVEL))
+
+#define disable_irq_save() \
+    set_irq_level(HIGHEST_IRQ_LEVEL)
+
+#define restore_irq(i) \
+    ((void)set_irq_level(i))
+
 static inline uint16_t swap16(uint16_t value)
   /*
     result[15..8] = value[ 7..0];