39 files changed, 230 insertions, 131 deletions

diff --git a/firmware/target/arm/i2c-pp.c b/firmware/target/arm/i2c-pp.c
index 1cfbfaeff1..450effc32d 100644
--- a/firmware/target/arm/i2c-pp.c
+++ b/firmware/target/arm/i2c-pp.c
@@ -60,7 +60,7 @@ static int pp_i2c_read_byte(unsigned int addr, unsigned int *data)
 
     {
         unsigned int byte;
-        int old_irq_level = set_irq_level(HIGHEST_IRQ_LEVEL);
+        int old_irq_level = disable_irq_save();
 
         /* clear top 15 bits, left shift 1, or in 0x1 for a read */
         I2C_ADDR = ((addr << 17) >> 16) | 0x1 ;
@@ -69,19 +69,19 @@ static int pp_i2c_read_byte(unsigned int addr, unsigned int *data)
 
         I2C_CTRL |= I2C_SEND;
 
-        set_irq_level(old_irq_level);
+        restore_irq(old_irq_level);
         if (pp_i2c_wait_not_busy() < 0)
         {
             return -1;
         }
-        old_irq_level = set_irq_level(HIGHEST_IRQ_LEVEL);
+        old_irq_level = disable_irq_save();
 
         byte = I2C_DATA(0);
 
         if (data)
             *data = byte;
 
-        set_irq_level(old_irq_level);
+        restore_irq(old_irq_level);
     }
 
     return 0;
@@ -102,7 +102,7 @@ static int pp_i2c_send_bytes(unsigned int addr, unsigned int len, unsigned char
     }
 
     {
-        int old_irq_level = set_irq_level(HIGHEST_IRQ_LEVEL);
+        int old_irq_level = disable_irq_save();
 
         /* clear top 15 bits, left shift 1 */
         I2C_ADDR = (addr << 17) >> 16;
@@ -118,7 +118,7 @@ static int pp_i2c_send_bytes(unsigned int addr, unsigned int len, unsigned char
 
         I2C_CTRL |= I2C_SEND;
 
-        set_irq_level(old_irq_level);
+        restore_irq(old_irq_level);
     }
 
     return 0x0;
diff --git a/firmware/target/arm/ipod/backlight-nano_video.c b/firmware/target/arm/ipod/backlight-nano_video.c
index 6d77e2bd03..647bab9ac6 100644
--- a/firmware/target/arm/ipod/backlight-nano_video.c
+++ b/firmware/target/arm/ipod/backlight-nano_video.c
@@ -43,11 +43,11 @@ void _backlight_set_brightness(int val)
     {
         do
         {
-            oldlevel = set_irq_level(HIGHEST_IRQ_LEVEL);
+            oldlevel = disable_irq_save();
             GPIO_CLEAR_BITWISE(GPIOD_OUTPUT_VAL, 0x80);
             udelay(10);
             GPIO_SET_BITWISE(GPIOD_OUTPUT_VAL, 0x80);
-            set_irq_level(oldlevel);
+            restore_irq(oldlevel);
             udelay(10);
         }
         while (++current_dim < val);
@@ -56,11 +56,11 @@ void _backlight_set_brightness(int val)
     {
         do
         {
-            oldlevel = set_irq_level(HIGHEST_IRQ_LEVEL);
+            oldlevel = disable_irq_save();
             GPIO_CLEAR_BITWISE(GPIOD_OUTPUT_VAL, 0x80);
             udelay(200);
             GPIO_SET_BITWISE(GPIOD_OUTPUT_VAL, 0x80);
-            set_irq_level(oldlevel);
+            restore_irq(oldlevel);
             udelay(10);
         }
         while (--current_dim > val);
diff --git a/firmware/target/arm/ipod/video/lcd-video.c b/firmware/target/arm/ipod/video/lcd-video.c
index d0c82e905c..0e1b072917 100644
--- a/firmware/target/arm/ipod/video/lcd-video.c
+++ b/firmware/target/arm/ipod/video/lcd-video.c
@@ -110,7 +110,7 @@ static void bcm_setup_rect(unsigned x, unsigned y,
 #ifndef BOOTLOADER
 static void lcd_tick(void)
 {
-    /* No set_irq_level - already in interrupt context */
+    /* No core level interrupt mask - already in interrupt context */
 #if NUM_CORES > 1
     corelock_lock(&lcd_state.cl);
 #endif
@@ -143,7 +143,7 @@ static void lcd_tick(void)
 
 static inline void lcd_block_tick(void)
 {
-    int oldlevel = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int oldlevel = disable_irq_save();
 
 #if NUM_CORES > 1
     corelock_lock(&lcd_state.cl);
@@ -152,14 +152,14 @@ static inline void lcd_block_tick(void)
 #else
     lcd_state.blocked = true;
 #endif
-    set_irq_level(oldlevel);
+    restore_irq(oldlevel);
 }
 
 static void lcd_unblock_and_update(void)
 {
     unsigned data;
     bool bcm_is_busy;
-    int oldlevel = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int oldlevel = disable_irq_save();
 
 #if NUM_CORES > 1
     corelock_lock(&lcd_state.cl);
@@ -184,7 +184,7 @@ static void lcd_unblock_and_update(void)
 #if NUM_CORES > 1
     corelock_unlock(&lcd_state.cl);
 #endif
-    set_irq_level(oldlevel);
+    restore_irq(oldlevel);
 }
 
 #else /* BOOTLOADER */
diff --git a/firmware/target/arm/pcm-pp.c b/firmware/target/arm/pcm-pp.c
index 5a9d3b3670..433e6e1e4f 100644
--- a/firmware/target/arm/pcm-pp.c
+++ b/firmware/target/arm/pcm-pp.c
@@ -223,24 +223,24 @@ void fiq_playback(void)
    will require other measures */
 void pcm_play_lock(void)
 {
-    int status = set_fiq_status(FIQ_DISABLED);
+    int status = disable_fiq_save();
 
     if (++dma_play_data.locked == 1) {
         IIS_IRQTX_REG &= ~IIS_IRQTX;
     }
 
-    set_fiq_status(status);
+    restore_fiq(status);
 }
 
 void pcm_play_unlock(void)
 {
-   int status = set_fiq_status(FIQ_DISABLED);
+   int status = disable_fiq_save();
 
     if (--dma_play_data.locked == 0 && dma_play_data.state != 0) {
         IIS_IRQTX_REG |= IIS_IRQTX;
     }
 
-   set_fiq_status(status);
+   restore_fiq(status);
 }
 
 static void play_start_pcm(void)
@@ -373,22 +373,22 @@ static struct dma_data dma_rec_data NOCACHEBSS_ATTR =
    will require other measures */
 void pcm_rec_lock(void)
 {
-    int status = set_fiq_status(FIQ_DISABLED);
+    int status = disable_fiq_save();
 
     if (++dma_rec_data.locked == 1)
         IIS_IRQRX_REG &= ~IIS_IRQRX;
 
-    set_fiq_status(status);
+    restore_fiq(status);
 }
 
 void pcm_rec_unlock(void)
 {
-    int status = set_fiq_status(FIQ_DISABLED);
+    int status = disable_fiq_save();
 
     if (--dma_rec_data.locked == 0 && dma_rec_data.state != 0)
         IIS_IRQRX_REG |= IIS_IRQRX;
 
-    set_fiq_status(status);
+    restore_fiq(status);
 }
 
 /* NOTE: direct stack use forbidden by GCC stack handling bug for FIQ */
diff --git a/firmware/target/arm/pnx0101/iriver-ifp7xx/power-ifp7xx.c b/firmware/target/arm/pnx0101/iriver-ifp7xx/power-ifp7xx.c
index b219244510..4494742bb8 100644
--- a/firmware/target/arm/pnx0101/iriver-ifp7xx/power-ifp7xx.c
+++ b/firmware/target/arm/pnx0101/iriver-ifp7xx/power-ifp7xx.c
@@ -55,11 +55,10 @@ bool ide_powered(void)
 
 void power_off(void)
 {
-    set_irq_level(HIGHEST_IRQ_LEVEL);
+    disable_interrupt(IRQ_FIQ_STATUS);
     GPIO1_CLR = 1 << 16;
     GPIO2_SET = 1;
-    while(1)
-        yield();
+    while(1);
 }
 
 #else
diff --git a/firmware/target/arm/pnx0101/system-pnx0101.c b/firmware/target/arm/pnx0101/system-pnx0101.c
index da94f397ca..bedcff04ea 100644
--- a/firmware/target/arm/pnx0101/system-pnx0101.c
+++ b/firmware/target/arm/pnx0101/system-pnx0101.c
@@ -113,7 +113,7 @@ static inline void *noncached(void *p)
 static void do_set_mem_timings(void) ICODE_ATTR;
 static void do_set_mem_timings(void)
 {
-    int old_irq = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int old_irq = disable_irq_save();
     while ((EMC.status & 3) != 0);
     EMC.control = 5;
     EMCSTATIC0.waitrd = 6;
@@ -130,7 +130,7 @@ static void do_set_mem_timings(void)
     EMCSTATIC1.config = 0x80081;
 #endif
     EMC.control = 1;
-    set_irq_level(old_irq);
+    restore_irq(old_irq);
 }
 
 static void emc_set_mem_timings(void)
diff --git a/firmware/target/arm/s3c2440/gigabeat-fx/pcm-meg-fx.c b/firmware/target/arm/s3c2440/gigabeat-fx/pcm-meg-fx.c
index 7f25cb6a15..00be543bb6 100644
--- a/firmware/target/arm/s3c2440/gigabeat-fx/pcm-meg-fx.c
+++ b/firmware/target/arm/s3c2440/gigabeat-fx/pcm-meg-fx.c
@@ -66,27 +66,27 @@ static void _pcm_apply_settings(void)
 
 void pcm_apply_settings(void)
 {
-    int oldstatus = set_fiq_status(FIQ_DISABLED);
+    int status = disable_fiq_save();
     _pcm_apply_settings();
-    set_fiq_status(oldstatus);
+    restore_fiq(status);
 }
 
 /* For the locks, DMA interrupt must be disabled because the handler
    manipulates INTMSK and the operation is not atomic */
 void pcm_play_lock(void)
 {
-    int status = set_fiq_status(FIQ_DISABLED);
+    int status = disable_fiq_save();
     if (++dma_play_lock.locked == 1)
         INTMSK |= (1<<19); /* Mask the DMA interrupt */
-    set_fiq_status(status);
+    restore_fiq(status);
 }
 
 void pcm_play_unlock(void)
 {
-    int status = set_fiq_status(FIQ_DISABLED);
+    int status = disable_fiq_save();
     if (--dma_play_lock.locked == 0)
         INTMSK &= ~dma_play_lock.state; /* Unmask the DMA interrupt if enabled */
-    set_fiq_status(status);
+    restore_fiq(status);
 }
 
 void pcm_play_dma_init(void)
diff --git a/firmware/target/arm/s3c2440/gigabeat-fx/timer-meg-fx.c b/firmware/target/arm/s3c2440/gigabeat-fx/timer-meg-fx.c
index 7df20f7149..b59e95806d 100644
--- a/firmware/target/arm/s3c2440/gigabeat-fx/timer-meg-fx.c
+++ b/firmware/target/arm/s3c2440/gigabeat-fx/timer-meg-fx.c
@@ -66,7 +66,7 @@ bool __timer_set(long cycles, bool start)
             pfn_unregister = NULL;
         }
 
-        oldlevel = set_irq_level(HIGHEST_IRQ_LEVEL);
+        oldlevel = disable_irq_save();
 
         TCMPB0 = 0;
         TCNTB0 = (unsigned int)cycles / prescaler;
@@ -77,7 +77,7 @@ bool __timer_set(long cycles, bool start)
         TCFG0 = (TCFG0 & ~0xff) | (prescaler - 1);
         TCFG1 = (TCFG1 & ~0xf) | divider;
 
-        set_irq_level(oldlevel);
+        restore_irq(oldlevel);
 
         retval = true;
     }
diff --git a/firmware/target/arm/system-arm.h b/firmware/target/arm/system-arm.h
index 774cdbcff4..3f1dfb16c8 100644
--- a/firmware/target/arm/system-arm.h
+++ b/firmware/target/arm/system-arm.h
@@ -74,27 +74,7 @@ static inline uint32_t swap_odd_even32(uint32_t value)
     return value;
 }
 
-static inline void enable_fiq(void)
-{
-    /* Clear FIQ disable bit */
-    asm volatile (
-        "mrs     r0, cpsr         \n"\
-        "bic     r0, r0, #0x40    \n"\
-        "msr     cpsr_c, r0         "
-        : : : "r0"
-    );
-}
-
-static inline void disable_fiq(void)
-{
-    /* Set FIQ disable bit */
-    asm volatile (
-        "mrs     r0, cpsr         \n"\
-        "orr     r0, r0, #0x40    \n"\
-        "msr     cpsr_c, r0         "
-        : : : "r0"
-    );
-}
+/* Core-level interrupt masking */
 
 /* This one returns the old status */
 #define IRQ_ENABLED      0x00
@@ -108,8 +88,10 @@ static inline void disable_fiq(void)
 #define IRQ_FIQ_STATUS   0xc0
 #define HIGHEST_IRQ_LEVEL IRQ_DISABLED
 
-#define set_irq_level(status)  set_interrupt_status((status), IRQ_STATUS)
-#define set_fiq_status(status) set_interrupt_status((status), FIQ_STATUS)
+#define set_irq_level(status) \
+    set_interrupt_status((status), IRQ_STATUS)
+#define set_fiq_status(status) \
+    set_interrupt_status((status), FIQ_STATUS)
 
 static inline int set_interrupt_status(int status, int mask)
 {
@@ -122,10 +104,75 @@ static inline int set_interrupt_status(int status, int mask)
         "orr    %0, %0, %2      \n"
         "msr    cpsr_c, %0      \n"
         : "=&r,r"(cpsr), "=&r,r"(oldstatus)
-        : "r,i"(status & mask), [mask]"i,i"(mask)
-    );
+        : "r,i"(status & mask), [mask]"i,i"(mask));
 
     return oldstatus;
 }
 
+static inline void enable_interrupt(int mask)
+{
+    /* Clear I and/or F disable bit */
+    int tmp;
+    asm volatile (
+        "mrs     %0, cpsr   \n"
+        "bic     %0, %0, %1 \n"
+        "msr     cpsr_c, %0 \n"
+        : "=&r"(tmp) : "i"(mask));
+}
+
+static inline void disable_interrupt(int mask)
+{
+    /* Set I and/or F disable bit */
+    int tmp;
+    asm volatile (
+        "mrs     %0, cpsr   \n"
+        "orr     %0, %0, %1 \n"
+        "msr     cpsr_c, %0 \n"
+        : "=&r"(tmp) : "i"(mask));
+}
+
+#define disable_irq(void) \
+    disable_interrupt(IRQ_STATUS)
+
+#define enable_irq(void) \
+    enable_interrupt(IRQ_STATUS)
+
+#define disable_fiq(void) \
+    disable_interrupt(FIQ_STATUS)
+
+#define enable_fiq(void) \
+    enable_interrupt(FIQ_STATUS)
+
+static inline int disable_interrupt_save(int mask)
+{
+    /* Set I and/or F disable bit and return old cpsr value */
+    int cpsr, tmp;
+    asm volatile (
+        "mrs     %1, cpsr   \n"
+        "orr     %0, %1, %2 \n"
+        "msr     cpsr_c, %0 \n"
+        : "=&r"(tmp), "=&r"(cpsr)
+        : "i"(mask));
+    return cpsr;
+}
+
+#define disable_irq_save() \
+    disable_interrupt_save(IRQ_STATUS)
+
+#define disable_fiq_save() \
+    disable_interrupt_save(FIQ_STATUS)
+
+static inline void restore_interrupt(int cpsr)
+{
+    /* Set cpsr_c from value returned by disable_interrupt_save
+     * or set_interrupt_status */
+    asm volatile ("msr cpsr_c, %0" : : "r"(cpsr));
+}
+
+#define restore_irq(cpsr) \
+    restore_interrupt(cpsr)
+
+#define restore_fiq(cpsr) \
+    restore_interrupt(cpsr)
+
 #endif /* SYSTEM_ARM_H */
diff --git a/firmware/target/arm/tatung/tpj1022/backlight-tpj1022.c b/firmware/target/arm/tatung/tpj1022/backlight-tpj1022.c
index 933ad5e930..a466cd93dd 100644
--- a/firmware/target/arm/tatung/tpj1022/backlight-tpj1022.c
+++ b/firmware/target/arm/tatung/tpj1022/backlight-tpj1022.c
@@ -28,17 +28,17 @@
 void _backlight_on(void)
 {
 #if 0
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level = disable_irq_save();
     pcf50606_write(0x38, 0xb0); /* Backlight ON, GPO1INV=1, GPO1ACT=011 */
-    set_irq_level(level);
+    restore_irq(level);
 #endif
 }
 
 void _backlight_off(void)
 {
 #if 0
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level = disable_irq_save();
     pcf50606_write(0x38, 0x80); /* Backlight OFF, GPO1INV=1, GPO1ACT=000 */
-    set_irq_level(level);
+    restore_irq(level);
 #endif
 }
diff --git a/firmware/target/arm/tms320dm320/dsp-dm320.c b/firmware/target/arm/tms320dm320/dsp-dm320.c
index f2ca954b24..e082cf7e4d 100644
--- a/firmware/target/arm/tms320dm320/dsp-dm320.c
+++ b/firmware/target/arm/tms320dm320/dsp-dm320.c
@@ -85,7 +85,7 @@ void dsp_wake(void)
 {
     /* If this is called concurrently, we may overlap setting and resetting the
        bit, which causes lost interrupts to the DSP. */
-    int old_level = set_irq_level(IRQ_DISABLED);
+    int old_level = disable_irq_save();
     
     /* The first time you INT0 the DSP, the ROM loader will branch to your RST
        handler. Subsequent times, your INT0 handler will get executed. */
@@ -93,7 +93,7 @@ void dsp_wake(void)
     nop; nop;
     IO_DSPC_HPIB_CONTROL |= 1 << 7;
     
-    set_irq_level(old_level);
+    restore_irq(old_level);
 }
 
 static void dsp_load(const struct dsp_section *im)
diff --git a/firmware/target/arm/tms320dm320/timer-dm320.c b/firmware/target/arm/tms320dm320/timer-dm320.c
index 482fef9f12..e1e051d3a5 100644
--- a/firmware/target/arm/tms320dm320/timer-dm320.c
+++ b/firmware/target/arm/tms320dm320/timer-dm320.c
@@ -48,7 +48,7 @@ bool __timer_set(long cycles, bool start)
         pfn_unregister = NULL;
     }
 
-    oldlevel = set_irq_level(HIGHEST_IRQ_LEVEL);
+    oldlevel = disable_irq_save();
 
     /* Increase prescale values starting from 0 to make the cycle count fit */
     while(divider>65535 && prescaler<1024)
@@ -60,7 +60,7 @@ bool __timer_set(long cycles, bool start)
     IO_TIMER0_TMPRSCL = prescaler;
     IO_TIMER0_TMDIV = divider;
 
-    set_irq_level(oldlevel);
+    restore_irq(oldlevel);
 
     return true;
 }
diff --git a/firmware/target/coldfire/iaudio/adc-iaudio.c b/firmware/target/coldfire/iaudio/adc-iaudio.c
index 1895cacfe9..5a2de24692 100644
--- a/firmware/target/coldfire/iaudio/adc-iaudio.c
+++ b/firmware/target/coldfire/iaudio/adc-iaudio.c
@@ -44,7 +44,7 @@ unsigned short adc_scan(int channel)
     int level;
     int data;
 
-    level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    level = disable_irq_save();
 
     pcf50606_write(0x2f, adcc2_parms[channel]);
     data = pcf50606_read(0x30);
@@ -52,7 +52,7 @@ unsigned short adc_scan(int channel)
     if (channel == ADC_BATTERY)
         data = get_10bit_voltage(data);
 
-    set_irq_level(level);
+    restore_irq(level);
 
     return (unsigned short)data;
 }
diff --git a/firmware/target/coldfire/iaudio/m3/audio-m3.c b/firmware/target/coldfire/iaudio/m3/audio-m3.c
index 4edae48744..da8c43c405 100644
--- a/firmware/target/coldfire/iaudio/m3/audio-m3.c
+++ b/firmware/target/coldfire/iaudio/m3/audio-m3.c
@@ -33,7 +33,7 @@ void audio_set_output_source(int source)
         txsrc = (4 << 8); /* recording, iis1RcvData */
 
     IIS1CONFIG = (IIS1CONFIG & ~(7 << 8)) | txsrc;
-    set_irq_level(level);
+    restore_irq(level);
 } /* audio_set_output_source */
 
 void audio_input_mux(int source, unsigned flags)
diff --git a/firmware/target/coldfire/iaudio/m5/audio-m5.c b/firmware/target/coldfire/iaudio/m5/audio-m5.c
index 87a7c35574..024621be64 100644
--- a/firmware/target/coldfire/iaudio/m5/audio-m5.c
+++ b/firmware/target/coldfire/iaudio/m5/audio-m5.c
@@ -32,7 +32,7 @@ void audio_set_output_source(int source)
         txsrc = (4 << 8); /* recording, iis1RcvData */
 
     IIS1CONFIG = (IIS1CONFIG & ~(7 << 8)) | txsrc;
-    set_irq_level(level);
+    restore_irq(level);
 } /* audio_set_output_source */
 
 void audio_input_mux(int source, unsigned flags)
diff --git a/firmware/target/coldfire/iaudio/m5/backlight-m5.c b/firmware/target/coldfire/iaudio/m5/backlight-m5.c
index 19bc5bfcae..3461a330ec 100644
--- a/firmware/target/coldfire/iaudio/m5/backlight-m5.c
+++ b/firmware/target/coldfire/iaudio/m5/backlight-m5.c
@@ -33,18 +33,18 @@ bool _backlight_init(void)
 
 void _backlight_on(void)
 {
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level = disable_irq_save();
 
     pcf50606_write(0x39, 0x07);
-    set_irq_level(level);
+    restore_irq(level);
 }
 
 void _backlight_off(void)
 {
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level = disable_irq_save();
 
     pcf50606_write(0x39, 0x00);
-    set_irq_level(level);
+    restore_irq(level);
 }
 
 void _remote_backlight_on(void)
diff --git a/firmware/target/coldfire/iaudio/m5/power-m5.c b/firmware/target/coldfire/iaudio/m5/power-m5.c
index 939cae02f2..18401af49f 100644
--- a/firmware/target/coldfire/iaudio/m5/power-m5.c
+++ b/firmware/target/coldfire/iaudio/m5/power-m5.c
@@ -44,16 +44,16 @@ bool charger_inserted(void)
 void ide_power_enable(bool on)
 {
     /* GPOOD3 */
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level = disable_irq_save();
     pcf50606_write(0x3c, on ? 0x07 : 0x00);
-    set_irq_level(level);
+    restore_irq(level);
 }
 
 bool ide_powered(void)
 {
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level = disable_irq_save();
     int value = pcf50606_read(0x3c);
-    set_irq_level(level);
+    restore_irq(level);
     return (value & 0x07) != 0;
 }
 
diff --git a/firmware/target/coldfire/iaudio/pcf50606-iaudio.c b/firmware/target/coldfire/iaudio/pcf50606-iaudio.c
index 0614355b5d..14b45e78b5 100644
--- a/firmware/target/coldfire/iaudio/pcf50606-iaudio.c
+++ b/firmware/target/coldfire/iaudio/pcf50606-iaudio.c
@@ -94,9 +94,9 @@ void pcf50606_init(void)
 
 void pcf50606_reset_timeout(void)
 {
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level = disable_irq_save();
     pcf50606_write(0x08, pcf50606_read(0x08) | 0x02); /* OOCC1 - TOTRST=1 */
-    set_irq_level(level);
+    restore_irq(level);
 }
 
 /* Handles interrupts generated by the pcf50606 */
diff --git a/firmware/target/coldfire/iaudio/x5/audio-x5.c b/firmware/target/coldfire/iaudio/x5/audio-x5.c
index 594ff3b574..0ae5f6023a 100644
--- a/firmware/target/coldfire/iaudio/x5/audio-x5.c
+++ b/firmware/target/coldfire/iaudio/x5/audio-x5.c
@@ -32,7 +32,7 @@ void audio_set_output_source(int source)
         txsrc = (4 << 8); /* recording, iis1RcvData */
 
     IIS1CONFIG = (IIS1CONFIG & ~(7 << 8)) | txsrc;
-    set_irq_level(level);
+    restore_irq(level);
 } /* audio_set_output_source */
 
 void audio_input_mux(int source, unsigned flags)
diff --git a/firmware/target/coldfire/iaudio/x5/backlight-x5.c b/firmware/target/coldfire/iaudio/x5/backlight-x5.c
index ebb28fbf2b..13ccad5adf 100644
--- a/firmware/target/coldfire/iaudio/x5/backlight-x5.c
+++ b/firmware/target/coldfire/iaudio/x5/backlight-x5.c
@@ -39,16 +39,16 @@ void _backlight_on(void)
 #ifndef BOOTLOADER
     _lcd_sleep_timer = 0; /* LCD should be awake already */
 #endif
-    level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    level = disable_irq_save();
     pcf50606_write(0x38, 0xb0); /* Backlight ON, GPO1INV=1, GPO1ACT=011 */
-    set_irq_level(level);
+    restore_irq(level);
 }
 
 void _backlight_off(void)
 {
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level = disable_irq_save();
     pcf50606_write(0x38, 0x80); /* Backlight OFF, GPO1INV=1, GPO1ACT=000 */
-    set_irq_level(level);
+    restore_irq(level);
     lcd_enable(false);
 #ifndef BOOTLOADER
     /* Start LCD sleep countdown */
@@ -66,10 +66,10 @@ void _backlight_off(void)
 void _backlight_set_brightness(int val)
 {
     /* disable IRQs while bitbanging */
-    int old_irq_level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int old_irq_level = disable_irq_save();
     pcf50606_write(0x35, (val << 1) | 0x01); /* 512Hz, Enable PWM */
     /* enable IRQs again */
-    set_irq_level(old_irq_level);
+    restore_irq(old_irq_level);
 }
 
 void _remote_backlight_on(void)
diff --git a/firmware/target/coldfire/iaudio/x5/ds2411-x5.c b/firmware/target/coldfire/iaudio/x5/ds2411-x5.c
index dc5a188ae1..a9bf20f727 100644
--- a/firmware/target/coldfire/iaudio/x5/ds2411-x5.c
+++ b/firmware/target/coldfire/iaudio/x5/ds2411-x5.c
@@ -134,7 +134,7 @@ static unsigned char ds2411_read_byte(void)
  */
 int ds2411_read_id(struct ds2411_id *id)
 {
-    int level = set_irq_level(DISABLE_INTERRUPTS); /* Timing sensitive */
+    int level = disable_irq_save(); /* Timing sensitive */
     int i;
     unsigned char crc;
 
@@ -208,7 +208,7 @@ int ds2411_read_id(struct ds2411_id *id)
         i = DS2411_NO_PRESENCE;
     }
 
-    set_irq_level(level);
+    restore_irq(level);
 
     return i;
 } /* ds2411_read_id */
diff --git a/firmware/target/coldfire/iaudio/x5/power-x5.c b/firmware/target/coldfire/iaudio/x5/power-x5.c
index 068b25f577..f5193aa559 100644
--- a/firmware/target/coldfire/iaudio/x5/power-x5.c
+++ b/firmware/target/coldfire/iaudio/x5/power-x5.c
@@ -44,16 +44,16 @@ bool charger_inserted(void)
 void ide_power_enable(bool on)
 {
     /* GPOOD3 */
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level = disable_irq_save();
     pcf50606_write(0x3c, on ? 0x07 : 0x00);
-    set_irq_level(level);
+    restore_irq(level);
 }
 
 bool ide_powered(void)
 {
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level = disable_irq_save();
     int value = pcf50606_read(0x3c);
-    set_irq_level(level);
+    restore_irq(level);
     return (value & 0x07) != 0;
 }
 
diff --git a/firmware/target/coldfire/iriver/audio-iriver.c b/firmware/target/coldfire/iriver/audio-iriver.c
index 4d22e7c987..51917b1338 100644
--- a/firmware/target/coldfire/iriver/audio-iriver.c
+++ b/firmware/target/coldfire/iriver/audio-iriver.c
@@ -41,7 +41,7 @@ void audio_set_output_source(int source)
 
     IIS2CONFIG = (IIS2CONFIG & ~(7 << 8)) | (txsrc_select[source+1] << 8);
 
-    set_irq_level(level);
+    restore_irq(level);
 } /* audio_set_output_source */
 
 void audio_input_mux(int source, unsigned flags)
diff --git a/firmware/target/coldfire/iriver/h100/adc-h100.c b/firmware/target/coldfire/iriver/h100/adc-h100.c
index 40fcc8925d..7ea7618b09 100644
--- a/firmware/target/coldfire/iriver/h100/adc-h100.c
+++ b/firmware/target/coldfire/iriver/h100/adc-h100.c
@@ -47,7 +47,7 @@
 
 unsigned short adc_scan(int channel)
 {
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level = disable_irq_save();
     unsigned char data = 0;
     int i;
     
@@ -97,7 +97,7 @@ unsigned short adc_scan(int channel)
 
     CS_HI;
 
-    set_irq_level(level);
+    restore_irq(level);
     return data;
 }
 
diff --git a/firmware/target/coldfire/iriver/h100/power-h100.c b/firmware/target/coldfire/iriver/h100/power-h100.c
index 5dc8618cc6..7ecf961842 100644
--- a/firmware/target/coldfire/iriver/h100/power-h100.c
+++ b/firmware/target/coldfire/iriver/h100/power-h100.c
@@ -115,8 +115,7 @@ void power_off(void)
     set_irq_level(DISABLE_INTERRUPTS);
     and_l(~0x00080000, &GPIO1_OUT);
     asm("halt");
-    while(1)
-        yield();
+    while(1);
 }
 
 #endif /* SIMULATOR */
diff --git a/firmware/target/coldfire/iriver/h100/spdif-h100.c b/firmware/target/coldfire/iriver/h100/spdif-h100.c
index beede3fdce..380622422c 100644
--- a/firmware/target/coldfire/iriver/h100/spdif-h100.c
+++ b/firmware/target/coldfire/iriver/h100/spdif-h100.c
@@ -99,7 +99,7 @@ void spdif_set_output_source(int source, bool src_on)
         PDOR3 = 0; /* A write to the FIFO kick-starts playback */
     }
 
-    set_irq_level(level);
+    restore_irq(level);
 } /* spdif_set_output_source */
 
 /* Return the last set S/PDIF audio source */
diff --git a/firmware/target/coldfire/iriver/h300/adc-h300.c b/firmware/target/coldfire/iriver/h300/adc-h300.c
index b13d0c73cc..efe5a9d746 100644
--- a/firmware/target/coldfire/iriver/h300/adc-h300.c
+++ b/firmware/target/coldfire/iriver/h300/adc-h300.c
@@ -34,7 +34,7 @@ static int adcc2_parms[] =
 
 unsigned short adc_scan(int channel)
 {
-    int level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int level = disable_irq_save();
     unsigned data;
 
     pcf50606_write(0x2f, adcc2_parms[channel]);
@@ -43,6 +43,6 @@ unsigned short adc_scan(int channel)
     if (channel == ADC_BATTERY)
         data = (data << 2) | (pcf50606_read(0x31) & 0x03);
 
-    set_irq_level(level);
+    restore_irq(level);
     return data;
 }
diff --git a/firmware/target/coldfire/iriver/h300/backlight-h300.c b/firmware/target/coldfire/iriver/h300/backlight-h300.c
index c0d441ad3f..f042ee5524 100644
--- a/firmware/target/coldfire/iriver/h300/backlight-h300.c
+++ b/firmware/target/coldfire/iriver/h300/backlight-h300.c
@@ -51,10 +51,10 @@ void _backlight_off(void)
 void _backlight_set_brightness(int val)
 {
     /* disable IRQs while bitbanging */
-    int old_irq_level = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int old_irq_level = disable_irq_save();
     pcf50606_write(0x35, (val << 1) | 0x01); /* 512Hz, Enable PWM */
     /* enable IRQs again */
-    set_irq_level(old_irq_level);
+    restore_irq(old_irq_level);
 }
 
 void _remote_backlight_on(void)
diff --git a/firmware/target/coldfire/iriver/h300/power-h300.c b/firmware/target/coldfire/iriver/h300/power-h300.c
index 21c723da8e..a06763e555 100644
--- a/firmware/target/coldfire/iriver/h300/power-h300.c
+++ b/firmware/target/coldfire/iriver/h300/power-h300.c
@@ -86,8 +86,7 @@ void power_off(void)
     set_irq_level(DISABLE_INTERRUPTS);
     and_l(~0x00080000, &GPIO1_OUT);
     asm("halt");
-    while(1)
-        yield();
+    while(1);
 }
 
 #endif /* SIMULATOR */
diff --git a/firmware/target/coldfire/iriver/lcd-remote-iriver.c b/firmware/target/coldfire/iriver/lcd-remote-iriver.c
index cab7cc4104..2fe5d6c3c1 100644
--- a/firmware/target/coldfire/iriver/lcd-remote-iriver.c
+++ b/firmware/target/coldfire/iriver/lcd-remote-iriver.c
@@ -478,9 +478,9 @@ static void remote_tick(void)
             if (!(countdown % 8))
             {
                 /* Determine which type of remote it is */
-                level = set_irq_level(HIGHEST_IRQ_LEVEL);
+                level = disable_irq_save();
                 val = adc_scan(ADC_REMOTEDETECT);
-                set_irq_level(level);
+                restore_irq(level);
 
                 if (val < ADCVAL_H100_LCD_REMOTE_HOLD)
                 {
diff --git a/firmware/target/coldfire/pcm-coldfire.c b/firmware/target/coldfire/pcm-coldfire.c
index 105ad51de6..2614946543 100644
--- a/firmware/target/coldfire/pcm-coldfire.c
+++ b/firmware/target/coldfire/pcm-coldfire.c
@@ -158,7 +158,7 @@ void _pcm_apply_settings_irq_lock(bool clear_reset)
 {
     int level = set_irq_level(DMA_IRQ_LEVEL);
     _pcm_apply_settings(clear_reset);
-    set_irq_level(level);
+    restore_irq(level);
 }
 
 /* This clears the reset bit to enable monitoring immediately if monitoring
@@ -175,7 +175,7 @@ void pcm_apply_settings(void)
     if (_pcm_apply_settings(!pbm || kick) && kick)
         PDOR3 = 0; /* Kick FIFO out of reset by writing to it */
 
-    set_irq_level(level);
+    restore_irq(level);
 } /* pcm_apply_settings */
 
 void pcm_play_dma_init(void)
diff --git a/firmware/target/coldfire/system-coldfire.c b/firmware/target/coldfire/system-coldfire.c
index 60f7ab12ad..67c684f95a 100644
--- a/firmware/target/coldfire/system-coldfire.c
+++ b/firmware/target/coldfire/system-coldfire.c
@@ -351,5 +351,5 @@ void coldfire_set_dataincontrol(unsigned long value)
     /* Have to be atomic against recording stop initiated by DMA1 */
     int level = set_irq_level(DMA_IRQ_LEVEL);
     DATAINCONTROL = (DATAINCONTROL & (1 << 9)) | value;
-    set_irq_level(level);
+    restore_irq(level);
 }
diff --git a/firmware/target/coldfire/system-target.h b/firmware/target/coldfire/system-target.h
index 8e3a2a3d5a..14b3207c0c 100644
--- a/firmware/target/coldfire/system-target.h
+++ b/firmware/target/coldfire/system-target.h
@@ -81,13 +81,54 @@ static inline int set_irq_level(int level)
 {
     int oldlevel;
     /* Read the old level and set the new one */
-    asm volatile ("move.w %%sr, %0 \n"
-                  "bset.l #13, %1  \n" /* Keep supervisor state set */
-                  "move.w %1, %%sr \n"
-                  : "=d"(oldlevel), "+d"(level));
+
+    /* Not volatile - can be removed if oldlevel isn't used */
+    asm          ("move.w %%sr, %0" : "=d"(oldlevel));
+    /* Keep supervisor state set */
+    asm volatile ("move.w %0, %%sr \n" : : "d"(level | 0x2000));
+    return oldlevel;
+}
+
+/* Enable all interrupts */
+static inline void enable_irq(void)
+{
+    int tmp;
+    /* Using move.w over the compiler's move.l saves 2 bytes per instance */
+    asm volatile ("move.w %1, %0   \n"
+                  "move.w %0, %%sr \n"
+                  : "=&d"(tmp) : "i"(0x2000));
+}
+
+/* Disable interrupts up to HIGHEST_IRQ_LEVEL */
+static inline void disable_irq(void)
+{
+    int tmp;
+    /* Using move.w over the compiler's move.l saves 2 bytes per instance */
+    asm volatile ("move.w %1, %0   \n"
+                  "move.w %0, %%sr \n"
+                  : "=&d"(tmp)
+                  : "i"(0x2000 | HIGHEST_IRQ_LEVEL));
+}
+
+static inline int disable_irq_save(void)
+{
+    int oldlevel, tmp;
+    /* Using move.w over the compiler's move.l saves 2 bytes per instance */
+    asm volatile ("move.w %%sr, %1 \n"
+                  "move.w %2, %0   \n"
+                  "move.w %0, %%sr \n"
+                  : "=&d"(tmp), "=d"(oldlevel)
+                  : "i"(0x2000 | HIGHEST_IRQ_LEVEL));
     return oldlevel;
 }
 
+static inline void restore_irq(int oldlevel)
+{
+    /* Restore the sr value returned by disable_irq_save or
+     * set_irq_level */
+    asm volatile ("move.w %0, %%sr" : : "d"(oldlevel));
+}
+
 static inline uint16_t swap16(uint16_t value)
   /*
     result[15..8] = value[ 7..0];
diff --git a/firmware/target/sh/archos/fm_v2/power-fm_v2.c b/firmware/target/sh/archos/fm_v2/power-fm_v2.c
index 94a36339bb..ac23348d42 100644
--- a/firmware/target/sh/archos/fm_v2/power-fm_v2.c
+++ b/firmware/target/sh/archos/fm_v2/power-fm_v2.c
@@ -101,9 +101,8 @@ bool ide_powered(void)
 
 void power_off(void)
 {
-    set_irq_level(HIGHEST_IRQ_LEVEL);
+    disable_irq();
     and_b(~0x20, &PBDRL);
     or_b(0x20, &PBIORL);
-    while(1)
-        yield();
+    while(1);
 }
diff --git a/firmware/target/sh/archos/ondio/power-ondio.c b/firmware/target/sh/archos/ondio/power-ondio.c
index 156516afeb..87f365791b 100644
--- a/firmware/target/sh/archos/ondio/power-ondio.c
+++ b/firmware/target/sh/archos/ondio/power-ondio.c
@@ -66,13 +66,12 @@ void power_init(void)
 
 void power_off(void)
 {
-    set_irq_level(HIGHEST_IRQ_LEVEL);
+    disable_irq();
 #ifdef HAVE_BACKLIGHT
     /* Switch off the light on backlight-modded Ondios */
     _backlight_off();
 #endif
     and_b(~0x20, &PBDRL);
     or_b(0x20, &PBIORL);
-    while(1)
-        yield();
+    while(1);
 }
diff --git a/firmware/target/sh/archos/player/power-player.c b/firmware/target/sh/archos/player/power-player.c
index 7d9d0d7d16..b2f51b9280 100644
--- a/firmware/target/sh/archos/player/power-player.c
+++ b/firmware/target/sh/archos/player/power-player.c
@@ -79,9 +79,8 @@ bool ide_powered(void)
 
 void power_off(void)
 {
-    set_irq_level(HIGHEST_IRQ_LEVEL);
+    disable_irq();
     and_b(~0x08, &PADRH);
     or_b(0x08, &PAIORH);
-    while(1)
-        yield();
+    while(1);
 }
diff --git a/firmware/target/sh/archos/recorder/power-recorder.c b/firmware/target/sh/archos/recorder/power-recorder.c
index 2af8df1bb6..1804bcb660 100644
--- a/firmware/target/sh/archos/recorder/power-recorder.c
+++ b/firmware/target/sh/archos/recorder/power-recorder.c
@@ -95,9 +95,8 @@ bool ide_powered(void)
 
 void power_off(void)
 {
-    set_irq_level(HIGHEST_IRQ_LEVEL);
+    disable_irq();
     and_b(~0x10, &PBDRL);
     or_b(0x10, &PBIORL);
-    while(1)
-        yield();
+    while(1);
 }
diff --git a/firmware/target/sh/system-sh.c b/firmware/target/sh/system-sh.c
index eec3ec18e4..f763e0ff53 100644
--- a/firmware/target/sh/system-sh.c
+++ b/firmware/target/sh/system-sh.c
@@ -360,7 +360,7 @@ void system_init(void)
 
 void system_reboot (void)
 {
-    set_irq_level(HIGHEST_IRQ_LEVEL);
+    disable_irq();
 
     asm volatile ("ldc\t%0,vbr" : : "r"(0));
 
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];