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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/cris/arch-v10/kernel/irq.c
Initial import
Diffstat (limited to 'arch/cris/arch-v10/kernel/irq.c')
-rw-r--r--arch/cris/arch-v10/kernel/irq.c235
1 files changed, 235 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/kernel/irq.c b/arch/cris/arch-v10/kernel/irq.c
new file mode 100644
index 000000000..09cae80a8
--- /dev/null
+++ b/arch/cris/arch-v10/kernel/irq.c
@@ -0,0 +1,235 @@
+/*
+ * linux/arch/cris/kernel/irq.c
+ *
+ * Copyright (c) 2000-2002 Axis Communications AB
+ *
+ * Authors: Bjorn Wesen (bjornw@axis.com)
+ *
+ * This file contains the interrupt vectors and some
+ * helper functions
+ *
+ */
+
+#include <asm/irq.h>
+#include <asm/current.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+
+#define crisv10_mask_irq(irq_nr) (*R_VECT_MASK_CLR = 1 << (irq_nr));
+#define crisv10_unmask_irq(irq_nr) (*R_VECT_MASK_SET = 1 << (irq_nr));
+
+extern void kgdb_init(void);
+extern void breakpoint(void);
+
+/* don't use set_int_vector, it bypasses the linux interrupt handlers. it is
+ * global just so that the kernel gdb can use it.
+ */
+
+void
+set_int_vector(int n, irqvectptr addr)
+{
+ etrax_irv->v[n + 0x20] = (irqvectptr)addr;
+}
+
+/* the breakpoint vector is obviously not made just like the normal irq handlers
+ * but needs to contain _code_ to jump to addr.
+ *
+ * the BREAK n instruction jumps to IBR + n * 8
+ */
+
+void
+set_break_vector(int n, irqvectptr addr)
+{
+ unsigned short *jinstr = (unsigned short *)&etrax_irv->v[n*2];
+ unsigned long *jaddr = (unsigned long *)(jinstr + 1);
+
+ /* if you don't know what this does, do not touch it! */
+
+ *jinstr = 0x0d3f;
+ *jaddr = (unsigned long)addr;
+
+ /* 00000026 <clrlop+1a> 3f0d82000000 jump 0x82 */
+}
+
+/*
+ * This builds up the IRQ handler stubs using some ugly macros in irq.h
+ *
+ * These macros create the low-level assembly IRQ routines that do all
+ * the operations that are needed. They are also written to be fast - and to
+ * disable interrupts as little as humanly possible.
+ *
+ */
+
+/* IRQ0 and 1 are special traps */
+void hwbreakpoint(void);
+void IRQ1_interrupt(void);
+BUILD_TIMER_IRQ(2, 0x04) /* the timer interrupt is somewhat special */
+BUILD_IRQ(3, 0x08)
+BUILD_IRQ(4, 0x10)
+BUILD_IRQ(5, 0x20)
+BUILD_IRQ(6, 0x40)
+BUILD_IRQ(7, 0x80)
+BUILD_IRQ(8, 0x100)
+BUILD_IRQ(9, 0x200)
+BUILD_IRQ(10, 0x400)
+BUILD_IRQ(11, 0x800)
+BUILD_IRQ(12, 0x1000)
+BUILD_IRQ(13, 0x2000)
+void mmu_bus_fault(void); /* IRQ 14 is the bus fault interrupt */
+void multiple_interrupt(void); /* IRQ 15 is the multiple IRQ interrupt */
+BUILD_IRQ(16, 0x10000 | 0x20000) /* ethernet tx interrupt needs to block rx */
+BUILD_IRQ(17, 0x20000 | 0x10000) /* ...and vice versa */
+BUILD_IRQ(18, 0x40000)
+BUILD_IRQ(19, 0x80000)
+BUILD_IRQ(20, 0x100000)
+BUILD_IRQ(21, 0x200000)
+BUILD_IRQ(22, 0x400000)
+BUILD_IRQ(23, 0x800000)
+BUILD_IRQ(24, 0x1000000)
+BUILD_IRQ(25, 0x2000000)
+/* IRQ 26-30 are reserved */
+BUILD_IRQ(31, 0x80000000)
+
+/*
+ * Pointers to the low-level handlers
+ */
+
+static void (*interrupt[NR_IRQS])(void) = {
+ NULL, NULL, IRQ2_interrupt, IRQ3_interrupt,
+ IRQ4_interrupt, IRQ5_interrupt, IRQ6_interrupt, IRQ7_interrupt,
+ IRQ8_interrupt, IRQ9_interrupt, IRQ10_interrupt, IRQ11_interrupt,
+ IRQ12_interrupt, IRQ13_interrupt, NULL, NULL,
+ IRQ16_interrupt, IRQ17_interrupt, IRQ18_interrupt, IRQ19_interrupt,
+ IRQ20_interrupt, IRQ21_interrupt, IRQ22_interrupt, IRQ23_interrupt,
+ IRQ24_interrupt, IRQ25_interrupt, NULL, NULL, NULL, NULL, NULL,
+ IRQ31_interrupt
+};
+
+static void enable_crisv10_irq(struct irq_data *data)
+{
+ crisv10_unmask_irq(data->irq);
+}
+
+static void disable_crisv10_irq(struct irq_data *data)
+{
+ crisv10_mask_irq(data->irq);
+}
+
+static struct irq_chip crisv10_irq_type = {
+ .name = "CRISv10",
+ .irq_shutdown = disable_crisv10_irq,
+ .irq_enable = enable_crisv10_irq,
+ .irq_disable = disable_crisv10_irq,
+};
+
+void weird_irq(void);
+void system_call(void); /* from entry.S */
+void do_sigtrap(void); /* from entry.S */
+void gdb_handle_breakpoint(void); /* from entry.S */
+
+extern void do_IRQ(int irq, struct pt_regs * regs);
+
+/* Handle multiple IRQs */
+void do_multiple_IRQ(struct pt_regs* regs)
+{
+ int bit;
+ unsigned masked;
+ unsigned mask;
+ unsigned ethmask = 0;
+
+ /* Get interrupts to mask and handle */
+ mask = masked = *R_VECT_MASK_RD;
+
+ /* Never mask timer IRQ */
+ mask &= ~(IO_MASK(R_VECT_MASK_RD, timer0));
+
+ /*
+ * If either ethernet interrupt (rx or tx) is active then block
+ * the other one too. Unblock afterwards also.
+ */
+ if (mask &
+ (IO_STATE(R_VECT_MASK_RD, dma0, active) |
+ IO_STATE(R_VECT_MASK_RD, dma1, active))) {
+ ethmask = (IO_MASK(R_VECT_MASK_RD, dma0) |
+ IO_MASK(R_VECT_MASK_RD, dma1));
+ }
+
+ /* Block them */
+ *R_VECT_MASK_CLR = (mask | ethmask);
+
+ /* An extra irq_enter here to prevent softIRQs to run after
+ * each do_IRQ. This will decrease the interrupt latency.
+ */
+ irq_enter();
+
+ /* Handle all IRQs */
+ for (bit = 2; bit < 32; bit++) {
+ if (masked & (1 << bit)) {
+ do_IRQ(bit, regs);
+ }
+ }
+
+ /* This irq_exit() will trigger the soft IRQs. */
+ irq_exit();
+
+ /* Unblock the IRQs again */
+ *R_VECT_MASK_SET = (masked | ethmask);
+}
+
+/* init_IRQ() is called by start_kernel and is responsible for fixing IRQ masks and
+ setting the irq vector table.
+*/
+
+void __init init_IRQ(void)
+{
+ int i;
+
+ /* clear all interrupt masks */
+ *R_IRQ_MASK0_CLR = 0xffffffff;
+ *R_IRQ_MASK1_CLR = 0xffffffff;
+ *R_IRQ_MASK2_CLR = 0xffffffff;
+ *R_VECT_MASK_CLR = 0xffffffff;
+
+ for (i = 0; i < 256; i++)
+ etrax_irv->v[i] = weird_irq;
+
+ /* Initialize IRQ handler descriptors. */
+ for(i = 2; i < NR_IRQS; i++) {
+ irq_set_chip_and_handler(i, &crisv10_irq_type,
+ handle_simple_irq);
+ set_int_vector(i, interrupt[i]);
+ }
+
+ /* the entries in the break vector contain actual code to be
+ executed by the associated break handler, rather than just a jump
+ address. therefore we need to setup a default breakpoint handler
+ for all breakpoints */
+ for (i = 0; i < 16; i++)
+ set_break_vector(i, do_sigtrap);
+
+ /* except IRQ 15 which is the multiple-IRQ handler on Etrax100 */
+ set_int_vector(15, multiple_interrupt);
+
+ /* 0 and 1 which are special breakpoint/NMI traps */
+ set_int_vector(0, hwbreakpoint);
+ set_int_vector(1, IRQ1_interrupt);
+
+ /* and irq 14 which is the mmu bus fault handler */
+ set_int_vector(14, mmu_bus_fault);
+
+ /* setup the system-call trap, which is reached by BREAK 13 */
+ set_break_vector(13, system_call);
+
+ /* setup a breakpoint handler for debugging used for both user and
+ kernel mode debugging (which is why it is not inside an ifdef
+ CONFIG_ETRAX_KGDB) */
+ set_break_vector(8, gdb_handle_breakpoint);
+
+#ifdef CONFIG_ETRAX_KGDB
+ /* setup kgdb if its enabled, and break into the debugger */
+ kgdb_init();
+ breakpoint();
+#endif
+}