/* * Copyright (C) 1999, 2000, 2006 MIPS Technologies, Inc. * All rights reserved. * Authors: Carsten Langgaard * Maciej W. Rozycki * * ######################################################################## * * This program is free software; you can distribute it and/or modify it * under the terms of the GNU General Public License (Version 2) as * published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. * * ######################################################################## * * Routines for generic manipulation of the interrupts found on the MIPS * Atlas board. * */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static struct atlas_ictrl_regs *atlas_hw0_icregs; #if 0 #define DEBUG_INT(x...) printk(x) #else #define DEBUG_INT(x...) #endif void disable_atlas_irq(unsigned int irq_nr) { atlas_hw0_icregs->intrsten = 1 << (irq_nr - ATLAS_INT_BASE); iob(); } void enable_atlas_irq(unsigned int irq_nr) { atlas_hw0_icregs->intseten = 1 << (irq_nr - ATLAS_INT_BASE); iob(); } static void end_atlas_irq(unsigned int irq) { if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS))) enable_atlas_irq(irq); } static struct irq_chip atlas_irq_type = { .name = "Atlas", .ack = disable_atlas_irq, .mask = disable_atlas_irq, .mask_ack = disable_atlas_irq, .unmask = enable_atlas_irq, .eoi = enable_atlas_irq, .end = end_atlas_irq, }; static inline int ls1bit32(unsigned int x) { int b = 31, s; s = 16; if (x << 16 == 0) s = 0; b -= s; x <<= s; s = 8; if (x << 8 == 0) s = 0; b -= s; x <<= s; s = 4; if (x << 4 == 0) s = 0; b -= s; x <<= s; s = 2; if (x << 2 == 0) s = 0; b -= s; x <<= s; s = 1; if (x << 1 == 0) s = 0; b -= s; return b; } static inline void atlas_hw0_irqdispatch(void) { unsigned long int_status; int irq; int_status = atlas_hw0_icregs->intstatus; /* if int_status == 0, then the interrupt has already been cleared */ if (unlikely(int_status == 0)) return; irq = ATLAS_INT_BASE + ls1bit32(int_status); DEBUG_INT("atlas_hw0_irqdispatch: irq=%d\n", irq); do_IRQ(irq); } 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 Atlas board look basically like (all external interrupt * sources are combined together on hardware interrupt 0 (MIPS IRQ 2)): * * MIPS IRQ Source * -------- ------ * 0 Software 0 (reschedule IPI on MT) * 1 Software 1 (remote call IPI on MT) * 2 Combined Atlas hardware interrupt (hw0) * 3 Hardware (ignored) * 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 ---- Software 0 * * then we just return, if multiple IRQs are pending then we will just take * another exception, big deal. */ asmlinkage void plat_irq_dispatch(void) { unsigned int pending = read_c0_cause() & read_c0_status() & ST0_IM; int irq; irq = irq_ffs(pending); if (irq == MIPSCPU_INT_ATLAS) atlas_hw0_irqdispatch(); else if (irq >= 0) do_IRQ(MIPSCPU_INT_BASE + irq); else spurious_interrupt(); } static inline void init_atlas_irqs (int base) { int i; atlas_hw0_icregs = (struct atlas_ictrl_regs *) ioremap(ATLAS_ICTRL_REGS_BASE, sizeof(struct atlas_ictrl_regs *)); /* * Mask out all interrupt by writing "1" to all bit position in * the interrupt reset reg. */ atlas_hw0_icregs->intrsten = 0xffffffff; for (i = ATLAS_INT_BASE; i <= ATLAS_INT_END; i++) set_irq_chip_and_handler(i, &atlas_irq_type, handle_level_irq); } static struct irqaction atlasirq = { .handler = no_action, .name = "Atlas cascade" }; msc_irqmap_t __initdata msc_irqmap[] = { {MSC01C_INT_TMR, MSC01_IRQ_EDGE, 0}, {MSC01C_INT_PCI, MSC01_IRQ_LEVEL, 0}, }; int __initdata msc_nr_irqs = ARRAY_SIZE(msc_irqmap); msc_irqmap_t __initdata msc_eicirqmap[] = { {MSC01E_INT_SW0, MSC01_IRQ_LEVEL, 0}, {MSC01E_INT_SW1, MSC01_IRQ_LEVEL, 0}, {MSC01E_INT_ATLAS, MSC01_IRQ_LEVEL, 0}, {MSC01E_INT_TMR, MSC01_IRQ_EDGE, 0}, {MSC01E_INT_PCI, MSC01_IRQ_LEVEL, 0}, {MSC01E_INT_PERFCTR, MSC01_IRQ_LEVEL, 0}, {MSC01E_INT_CPUCTR, MSC01_IRQ_LEVEL, 0} }; int __initdata msc_nr_eicirqs = ARRAY_SIZE(msc_eicirqmap); void __init arch_init_irq(void) { init_atlas_irqs(ATLAS_INT_BASE); if (!cpu_has_veic) mips_cpu_irq_init(); switch(mips_revision_corid) { case MIPS_REVISION_CORID_CORE_MSC: case MIPS_REVISION_CORID_CORE_FPGA2: case MIPS_REVISION_CORID_CORE_FPGA3: case MIPS_REVISION_CORID_CORE_24K: case MIPS_REVISION_CORID_CORE_EMUL_MSC: if (cpu_has_veic) init_msc_irqs (MSC01E_INT_BASE, MSC01E_INT_BASE, msc_eicirqmap, msc_nr_eicirqs); else init_msc_irqs (MSC01E_INT_BASE, MSC01C_INT_BASE, msc_irqmap, msc_nr_irqs); } if (cpu_has_veic) { set_vi_handler (MSC01E_INT_ATLAS, atlas_hw0_irqdispatch); setup_irq (MSC01E_INT_BASE + MSC01E_INT_ATLAS, &atlasirq); } else if (cpu_has_vint) { set_vi_handler (MIPSCPU_INT_ATLAS, atlas_hw0_irqdispatch); #ifdef CONFIG_MIPS_MT_SMTC setup_irq_smtc (MIPSCPU_INT_BASE + MIPSCPU_INT_ATLAS, &atlasirq, (0x100 << MIPSCPU_INT_ATLAS)); #else /* Not SMTC */ setup_irq(MIPSCPU_INT_BASE + MIPSCPU_INT_ATLAS, &atlasirq); #endif /* CONFIG_MIPS_MT_SMTC */ } else setup_irq(MIPSCPU_INT_BASE + MIPSCPU_INT_ATLAS, &atlasirq); }