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author | Jeff Garzik <jeff@garzik.org> | 2006-04-21 01:27:45 +0400 |
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committer | Jeff Garzik <jeff@garzik.org> | 2006-04-21 01:27:45 +0400 |
commit | 9707b27100a48950f1e15e08a7c5028786e47f55 (patch) | |
tree | 5745b1e7497ae1499a2e2e9e0a567996419ab34f /arch/mips/mips-boards/sead/sead_int.c | |
parent | 8fc65162a8f25929be80c8d6321a3479e92b5aae (diff) | |
parent | 402a26f0c040077ed6f941eefac5a6971f0d5f40 (diff) | |
download | linux-9707b27100a48950f1e15e08a7c5028786e47f55.tar.xz |
Merge branch 'master'
Diffstat (limited to 'arch/mips/mips-boards/sead/sead_int.c')
-rw-r--r-- | arch/mips/mips-boards/sead/sead_int.c | 86 |
1 files changed, 82 insertions, 4 deletions
diff --git a/arch/mips/mips-boards/sead/sead_int.c b/arch/mips/mips-boards/sead/sead_int.c index 90fda0d9915f..9168d934c661 100644 --- a/arch/mips/mips-boards/sead/sead_int.c +++ b/arch/mips/mips-boards/sead/sead_int.c @@ -24,16 +24,94 @@ #include <linux/irq.h> #include <asm/irq_cpu.h> +#include <asm/mipsregs.h> #include <asm/system.h> #include <asm/mips-boards/seadint.h> -extern asmlinkage void mipsIRQ(void); +static inline int clz(unsigned long x) +{ + __asm__ ( + " .set push \n" + " .set mips32 \n" + " clz %0, %1 \n" + " .set pop \n" + : "=r" (x) + : "r" (x)); + + return x; +} + +/* + * Version of ffs that only looks at bits 12..15. + */ +static inline unsigned int irq_ffs(unsigned int pending) +{ +#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64) + return -clz(pending) + 31 - CAUSEB_IP; +#else + unsigned int a0 = 7; + unsigned int t0; + + t0 = s0 & 0xf000; + t0 = t0 < 1; + t0 = t0 << 2; + a0 = a0 - t0; + s0 = s0 << t0; + + t0 = s0 & 0xc000; + t0 = t0 < 1; + t0 = t0 << 1; + a0 = a0 - t0; + s0 = s0 << t0; + + t0 = s0 & 0x8000; + t0 = t0 < 1; + //t0 = t0 << 2; + a0 = a0 - t0; + //s0 = s0 << t0; + + return a0; +#endif +} + +/* + * IRQs on the SEAD board look basically are combined together on hardware + * interrupt 0 (MIPS IRQ 2)) like: + * + * MIPS IRQ Source + * -------- ------ + * 0 Software (ignored) + * 1 Software (ignored) + * 2 UART0 (hw0) + * 3 UART1 (hw1) + * 4 Hardware (ignored) + * 5 Hardware (ignored) + * 6 Hardware (ignored) + * 7 R4k timer (what we use) + * + * We handle the IRQ according to _our_ priority which is: + * + * Highest ---- R4k Timer + * Lowest ---- Combined hardware interrupt + * + * then we just return, if multiple IRQs are pending then we will just take + * another exception, big deal. + */ +asmlinkage void plat_irq_dispatch(struct pt_regs *regs) +{ + unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM; + int irq; + + irq = irq_ffs(pending); + + if (irq >= 0) + do_IRQ(MIPSCPU_INT_BASE + irq, regs); + else + spurious_interrupt(regs); +} void __init arch_init_irq(void) { mips_cpu_irq_init(MIPSCPU_INT_BASE); - - /* Now safe to set the exception vector. */ - set_except_vector(0, mipsIRQ); } |