1 files changed, 431 insertions, 0 deletions

diff --git a/arch/mips/sibyte/sb1250/irq.c b/arch/mips/sibyte/sb1250/irq.c
new file mode 100644
index 000000000000..2728abbc94d2
--- /dev/null
+++ b/arch/mips/sibyte/sb1250/irq.c
@@ -0,0 +1,431 @@
+/*
+ * Copyright (C) 2000, 2001, 2002, 2003 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that 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.
+ */
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/smp.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/kernel_stat.h>
+
+#include <asm/errno.h>
+#include <asm/signal.h>
+#include <asm/system.h>
+#include <asm/ptrace.h>
+#include <asm/io.h>
+
+#include <asm/sibyte/sb1250_regs.h>
+#include <asm/sibyte/sb1250_int.h>
+#include <asm/sibyte/sb1250_uart.h>
+#include <asm/sibyte/sb1250_scd.h>
+#include <asm/sibyte/sb1250.h>
+
+/*
+ * These are the routines that handle all the low level interrupt stuff.
+ * Actions handled here are: initialization of the interrupt map, requesting of
+ * interrupt lines by handlers, dispatching if interrupts to handlers, probing
+ * for interrupt lines
+ */
+
+
+#define shutdown_sb1250_irq     disable_sb1250_irq
+static void end_sb1250_irq(unsigned int irq);
+static void enable_sb1250_irq(unsigned int irq);
+static void disable_sb1250_irq(unsigned int irq);
+static unsigned int startup_sb1250_irq(unsigned int irq);
+static void ack_sb1250_irq(unsigned int irq);
+#ifdef CONFIG_SMP
+static void sb1250_set_affinity(unsigned int irq, unsigned long mask);
+#endif
+
+#ifdef CONFIG_SIBYTE_HAS_LDT
+extern unsigned long ldt_eoi_space;
+#endif
+
+#ifdef CONFIG_KGDB
+static int kgdb_irq;
+
+/* Default to UART1 */
+int kgdb_port = 1;
+#ifdef CONFIG_SIBYTE_SB1250_DUART
+extern char sb1250_duart_present[];
+#endif
+#endif
+
+static struct hw_interrupt_type sb1250_irq_type = {
+        "SB1250-IMR",
+        startup_sb1250_irq,
+        shutdown_sb1250_irq,
+        enable_sb1250_irq,
+        disable_sb1250_irq,
+        ack_sb1250_irq,
+        end_sb1250_irq,
+#ifdef CONFIG_SMP
+        sb1250_set_affinity
+#else
+        NULL
+#endif
+};
+
+/* Store the CPU id (not the logical number) */
+int sb1250_irq_owner[SB1250_NR_IRQS];
+
+DEFINE_SPINLOCK(sb1250_imr_lock);
+
+void sb1250_mask_irq(int cpu, int irq)
+{
+        unsigned long flags;
+        u64 cur_ints;
+
+        spin_lock_irqsave(&sb1250_imr_lock, flags);
+        cur_ints = __bus_readq(IOADDR(A_IMR_MAPPER(cpu) +
+                                      R_IMR_INTERRUPT_MASK));
+        cur_ints |= (((u64) 1) << irq);
+        __bus_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
+                                      R_IMR_INTERRUPT_MASK));
+        spin_unlock_irqrestore(&sb1250_imr_lock, flags);
+}
+
+void sb1250_unmask_irq(int cpu, int irq)
+{
+        unsigned long flags;
+        u64 cur_ints;
+
+        spin_lock_irqsave(&sb1250_imr_lock, flags);
+        cur_ints = __bus_readq(IOADDR(A_IMR_MAPPER(cpu) +
+                                      R_IMR_INTERRUPT_MASK));
+        cur_ints &= ~(((u64) 1) << irq);
+        __bus_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
+                                      R_IMR_INTERRUPT_MASK));
+        spin_unlock_irqrestore(&sb1250_imr_lock, flags);
+}
+
+#ifdef CONFIG_SMP
+static void sb1250_set_affinity(unsigned int irq, unsigned long mask)
+{
+        int i = 0, old_cpu, cpu, int_on;
+        u64 cur_ints;
+        irq_desc_t *desc = irq_desc + irq;
+        unsigned long flags;
+
+        while (mask) {
+                if (mask & 1) {
+                        mask >>= 1;
+                        break;
+                }
+                mask >>= 1;
+                i++;
+        }
+
+        if (mask) {
+                printk("attempted to set irq affinity for irq %d to multiple CPUs\n", irq);
+                return;
+        }
+
+        /* Convert logical CPU to physical CPU */
+        cpu = cpu_logical_map(i);
+
+        /* Protect against other affinity changers and IMR manipulation */
+        spin_lock_irqsave(&desc->lock, flags);
+        spin_lock(&sb1250_imr_lock);
+
+        /* Swizzle each CPU's IMR (but leave the IP selection alone) */
+        old_cpu = sb1250_irq_owner[irq];
+        cur_ints = __bus_readq(IOADDR(A_IMR_MAPPER(old_cpu) +
+                               R_IMR_INTERRUPT_MASK));
+        int_on = !(cur_ints & (((u64) 1) << irq));
+        if (int_on) {
+                /* If it was on, mask it */
+                cur_ints |= (((u64) 1) << irq);
+                __bus_writeq(cur_ints, IOADDR(A_IMR_MAPPER(old_cpu) +
+                                              R_IMR_INTERRUPT_MASK));
+        }
+        sb1250_irq_owner[irq] = cpu;
+        if (int_on) {
+                /* unmask for the new CPU */
+                cur_ints = __bus_readq(IOADDR(A_IMR_MAPPER(cpu) +
+                                       R_IMR_INTERRUPT_MASK));
+                cur_ints &= ~(((u64) 1) << irq);
+                __bus_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) +
+                                              R_IMR_INTERRUPT_MASK));
+        }
+        spin_unlock(&sb1250_imr_lock);
+        spin_unlock_irqrestore(&desc->lock, flags);
+}
+#endif
+
+
+/* Defined in arch/mips/sibyte/sb1250/irq_handler.S */
+extern void sb1250_irq_handler(void);
+
+/*****************************************************************************/
+
+static unsigned int startup_sb1250_irq(unsigned int irq)
+{
+        sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
+
+        return 0;               /* never anything pending */
+}
+
+
+static void disable_sb1250_irq(unsigned int irq)
+{
+        sb1250_mask_irq(sb1250_irq_owner[irq], irq);
+}
+
+static void enable_sb1250_irq(unsigned int irq)
+{
+        sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
+}
+
+
+static void ack_sb1250_irq(unsigned int irq)
+{
+#ifdef CONFIG_SIBYTE_HAS_LDT
+        u64 pending;
+
+        /*
+         * If the interrupt was an HT interrupt, now is the time to
+         * clear it.  NOTE: we assume the HT bridge was set up to
+         * deliver the interrupts to all CPUs (which makes affinity
+         * changing easier for us)
+         */
+        pending = bus_readq(IOADDR(A_IMR_REGISTER(sb1250_irq_owner[irq],
+                                                  R_IMR_LDT_INTERRUPT)));
+        pending &= ((u64)1 << (irq));
+        if (pending) {
+                int i;
+                for (i=0; i<NR_CPUS; i++) {
+                        int cpu;
+#ifdef CONFIG_SMP
+                        cpu = cpu_logical_map(i);
+#else
+                        cpu = i;
+#endif
+                        /*
+                         * Clear for all CPUs so an affinity switch
+                         * doesn't find an old status
+                         */
+                        bus_writeq(pending,
+                                   IOADDR(A_IMR_REGISTER(cpu,
+                                                R_IMR_LDT_INTERRUPT_CLR)));
+                }
+
+                /*
+                 * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
+                 * Pass 2, the LDT world may be edge-triggered, but
+                 * this EOI shouldn't hurt.  If they are
+                 * level-sensitive, the EOI is required.
+                 */
+                *(uint32_t *)(ldt_eoi_space+(irq<<16)+(7<<2)) = 0;
+        }
+#endif
+        sb1250_mask_irq(sb1250_irq_owner[irq], irq);
+}
+
+
+static void end_sb1250_irq(unsigned int irq)
+{
+        if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
+                sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
+        }
+}
+
+
+void __init init_sb1250_irqs(void)
+{
+        int i;
+
+        for (i = 0; i < NR_IRQS; i++) {
+                irq_desc[i].status = IRQ_DISABLED;
+                irq_desc[i].action = 0;
+                irq_desc[i].depth = 1;
+                if (i < SB1250_NR_IRQS) {
+                        irq_desc[i].handler = &sb1250_irq_type;
+                        sb1250_irq_owner[i] = 0;
+                } else {
+                        irq_desc[i].handler = &no_irq_type;
+                }
+        }
+}
+
+
+static irqreturn_t  sb1250_dummy_handler(int irq, void *dev_id,
+        struct pt_regs *regs)
+{
+        return IRQ_NONE;
+}
+
+static struct irqaction sb1250_dummy_action = {
+        .handler = sb1250_dummy_handler,
+        .flags   = 0,
+        .mask    = CPU_MASK_NONE,
+        .name    = "sb1250-private",
+        .next    = NULL,
+        .dev_id  = 0
+};
+
+int sb1250_steal_irq(int irq)
+{
+        irq_desc_t *desc = irq_desc + irq;
+        unsigned long flags;
+        int retval = 0;
+
+        if (irq >= SB1250_NR_IRQS)
+                return -EINVAL;
+
+        spin_lock_irqsave(&desc->lock,flags);
+        /* Don't allow sharing at all for these */
+        if (desc->action != NULL)
+                retval = -EBUSY;
+        else {
+                desc->action = &sb1250_dummy_action;
+                desc->depth = 0;
+        }
+        spin_unlock_irqrestore(&desc->lock,flags);
+        return 0;
+}
+
+/*
+ *  arch_init_irq is called early in the boot sequence from init/main.c via
+ *  init_IRQ.  It is responsible for setting up the interrupt mapper and
+ *  installing the handler that will be responsible for dispatching interrupts
+ *  to the "right" place.
+ */
+/*
+ * For now, map all interrupts to IP[2].  We could save
+ * some cycles by parceling out system interrupts to different
+ * IP lines, but keep it simple for bringup.  We'll also direct
+ * all interrupts to a single CPU; we should probably route
+ * PCI and LDT to one cpu and everything else to the other
+ * to balance the load a bit.
+ *
+ * On the second cpu, everything is set to IP5, which is
+ * ignored, EXCEPT the mailbox interrupt.  That one is
+ * set to IP[2] so it is handled.  This is needed so we
+ * can do cross-cpu function calls, as requred by SMP
+ */
+
+#define IMR_IP2_VAL     K_INT_MAP_I0
+#define IMR_IP3_VAL     K_INT_MAP_I1
+#define IMR_IP4_VAL     K_INT_MAP_I2
+#define IMR_IP5_VAL     K_INT_MAP_I3
+#define IMR_IP6_VAL     K_INT_MAP_I4
+
+void __init arch_init_irq(void)
+{
+
+        unsigned int i;
+        u64 tmp;
+        unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
+                STATUSF_IP1 | STATUSF_IP0;
+
+        /* Default everything to IP2 */
+        for (i = 0; i < SB1250_NR_IRQS; i++) {  /* was I0 */
+                bus_writeq(IMR_IP2_VAL,
+                           IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
+                                  (i << 3)));
+                bus_writeq(IMR_IP2_VAL,
+                           IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MAP_BASE) +
+                                  (i << 3)));
+        }
+
+        init_sb1250_irqs();
+
+        /*
+         * Map the high 16 bits of the mailbox registers to IP[3], for
+         * inter-cpu messages
+         */
+        /* Was I1 */
+        bus_writeq(IMR_IP3_VAL,
+                   IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
+                          (K_INT_MBOX_0 << 3)));
+        bus_writeq(IMR_IP3_VAL,
+                   IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MAP_BASE) +
+                          (K_INT_MBOX_0 << 3)));
+
+        /* Clear the mailboxes.  The firmware may leave them dirty */
+        bus_writeq(0xffffffffffffffffULL,
+                   IOADDR(A_IMR_REGISTER(0, R_IMR_MAILBOX_CLR_CPU)));
+        bus_writeq(0xffffffffffffffffULL,
+                   IOADDR(A_IMR_REGISTER(1, R_IMR_MAILBOX_CLR_CPU)));
+
+        /* Mask everything except the mailbox registers for both cpus */
+        tmp = ~((u64) 0) ^ (((u64) 1) << K_INT_MBOX_0);
+        bus_writeq(tmp, IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MASK)));
+        bus_writeq(tmp, IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MASK)));
+
+        sb1250_steal_irq(K_INT_MBOX_0);
+
+        /*
+         * Note that the timer interrupts are also mapped, but this is
+         * done in sb1250_time_init().  Also, the profiling driver 
+         * does its own management of IP7.
+         */
+
+#ifdef CONFIG_KGDB
+        imask |= STATUSF_IP6;
+#endif
+        /* Enable necessary IPs, disable the rest */
+        change_c0_status(ST0_IM, imask);
+        set_except_vector(0, sb1250_irq_handler);
+
+#ifdef CONFIG_KGDB
+        if (kgdb_flag) {
+                kgdb_irq = K_INT_UART_0 + kgdb_port;
+
+#ifdef CONFIG_SIBYTE_SB1250_DUART       
+                sb1250_duart_present[kgdb_port] = 0;
+#endif
+                /* Setup uart 1 settings, mapper */
+                bus_writeq(M_DUART_IMR_BRK, IOADDR(A_DUART_IMRREG(kgdb_port)));
+
+                sb1250_steal_irq(kgdb_irq);
+                bus_writeq(IMR_IP6_VAL,
+                           IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
+                                  (kgdb_irq<<3)));
+                sb1250_unmask_irq(0, kgdb_irq);
+        }
+#endif
+}
+
+#ifdef CONFIG_KGDB
+
+#include <linux/delay.h>
+
+#define duart_out(reg, val)     csr_out32(val, IOADDR(A_DUART_CHANREG(kgdb_port,reg)))
+#define duart_in(reg)           csr_in32(IOADDR(A_DUART_CHANREG(kgdb_port,reg)))
+
+void sb1250_kgdb_interrupt(struct pt_regs *regs)
+{
+        /*
+         * Clear break-change status (allow some time for the remote
+         * host to stop the break, since we would see another
+         * interrupt on the end-of-break too)
+         */
+        kstat_this_cpu.irqs[kgdb_irq]++;
+        mdelay(500);
+        duart_out(R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT |
+                                M_DUART_RX_EN | M_DUART_TX_EN);
+        set_async_breakpoint(&regs->cp0_epc);
+}
+
+#endif  /* CONFIG_KGDB */