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authorMaurus Cuelenaere <mcuelenaere@gmail.com>2009-03-25 22:42:24 +0000
committerMaurus Cuelenaere <mcuelenaere@gmail.com>2009-03-25 22:42:24 +0000
commitb84c06372b7763aa5937173307c45fb44ed4e703 (patch)
tree6a31eb3b745166d311f4a6304697366137c8fd3a /firmware/target/mips
parent52cb340962505792bf9df1ee49bc400461624cd5 (diff)
downloadrockbox-b84c06372b7763aa5937173307c45fb44ed4e703.tar.gz
rockbox-b84c06372b7763aa5937173307c45fb44ed4e703.zip
Jz4740: Optimize interrupt handling by using a find_last_set_bit() implementation
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20539 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'firmware/target/mips')
-rw-r--r--firmware/target/mips/ingenic_jz47xx/system-jz4740.c25
1 files changed, 15 insertions, 10 deletions
diff --git a/firmware/target/mips/ingenic_jz47xx/system-jz4740.c b/firmware/target/mips/ingenic_jz47xx/system-jz4740.c
index 291716a309..d676d20be6 100644
--- a/firmware/target/mips/ingenic_jz47xx/system-jz4740.c
+++ b/firmware/target/mips/ingenic_jz47xx/system-jz4740.c
@@ -121,7 +121,6 @@ void system_enable_irq(unsigned int irq)
static void dis_irq(unsigned int irq)
{
register unsigned int t;
-
if ((irq >= IRQ_GPIO_0) && (irq <= IRQ_GPIO_0 + NUM_GPIO))
{
__gpio_mask_irq(irq - IRQ_GPIO_0);
@@ -161,14 +160,20 @@ static int get_irq_number(void)
ipl |= REG_INTC_IPR;
- if (ipl == 0)
+ if (UNLIKELY(ipl == 0))
return -1;
- for (irq = 31; irq >= 0; irq--)
- if (ipl & (1 << irq))
- break;
+ __asm__ __volatile__("negu $8, %0 \n"
+ "and $8, %0, $8 \n"
+ "clz %0, %1 \n"
+ "li $8, 31 \n"
+ "subu %0, $8, %0 \n"
+ : "=r" (irq)
+ : "r" (ipl)
+ : "t0"
+ );
- if (irq < 0)
+ if (UNLIKELY(irq < 0))
return -1;
ipl &= ~(1 << irq);
@@ -197,7 +202,7 @@ static int get_irq_number(void)
void intr_handler(void)
{
- int irq = get_irq_number();
+ register int irq = get_irq_number();
if(UNLIKELY(irq < 0))
return;
@@ -313,8 +318,8 @@ static void pll_init(void)
cfcr = CPM_CPCCR_CLKOEN |
CPM_CPCCR_PCS |
- (n2FR[div[0]] << CPM_CPCCR_CDIV_BIT) |
- (n2FR[div[1]] << CPM_CPCCR_HDIV_BIT) |
+ (n2FR[div[0]] << CPM_CPCCR_CDIV_BIT) |
+ (n2FR[div[1]] << CPM_CPCCR_HDIV_BIT) |
(n2FR[div[2]] << CPM_CPCCR_PDIV_BIT) |
(n2FR[div[3]] << CPM_CPCCR_MDIV_BIT) |
(n2FR[div[4]] << CPM_CPCCR_LDIV_BIT) |
@@ -327,7 +332,7 @@ static void pll_init(void)
nf = CPU_FREQ * 2 / CFG_EXTAL;
plcr1 = ((nf - 2) << CPM_CPPCR_PLLM_BIT) | /* FD */
- (0 << CPM_CPPCR_PLLN_BIT) | /* RD=0, NR=2 */
+ (0 << CPM_CPPCR_PLLN_BIT) | /* RD=0, NR=2 */
(0 << CPM_CPPCR_PLLOD_BIT) | /* OD=0, NO=1 */
(0x20 << CPM_CPPCR_PLLST_BIT) | /* PLL stable time */
CPM_CPPCR_PLLEN; /* enable PLL */