patch-2.4.20 linux-2.4.20/arch/mips/sibyte/sb1250/irq.c

• Lines: 203
• Date: Thu Nov 28 15:53:10 2002
• Orig file: linux-2.4.19/arch/mips/sibyte/sb1250/irq.c
• Orig date: Fri Aug 2 17:39:43 2002

diff -urN linux-2.4.19/arch/mips/sibyte/sb1250/irq.c linux-2.4.20/arch/mips/sibyte/sb1250/irq.c
@@ -10,7 +10,7 @@
  * 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.
@@ -23,21 +23,24 @@
 #include <linux/spinlock.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
+
 #include <asm/errno.h>
 #include <asm/signal.h>
 #include <asm/system.h>
 #include <asm/ptrace.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>
 #include <asm/sibyte/64bit.h>
 
 /*
- * These are the routines that handle all the low level interrupt stuff. 
+ * 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 
+ * for interrupt lines
  */
 
 
@@ -50,6 +53,15 @@
 
 #ifdef CONFIG_REMOTE_DEBUG
 extern void breakpoint(void);
+extern void set_debug_traps(void);
+
+/* kgdb is on when configured.  Pass "nokgdb" kernel arg to turn it off */
+static int kgdb_flag = 1;
+static int __init nokgdb(char *str)
+{
+	kgdb_flag = 0;
+}
+__setup("nokgdb", nokgdb);
 #endif
 
 #define NR_IRQS 64
@@ -155,11 +167,44 @@
 }
 
 
+static void sb1250_dummy_handler(int irq, void *dev_id, struct pt_regs *regs)
+{
+}
+
+static struct irqaction sb1250_dummy_action = {
+	handler: sb1250_dummy_handler,
+	flags:   0,
+	mask:    0,
+	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 >= 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);
+}
+
 /*
  *  init_IRQ is called early in the boot sequence from init/main.c.  It
  *  is responsible for setting up the interrupt mapper and installing the
  *  handler that will be responsible for dispatching interrupts to the
- *  "right" place. 
+ *  "right" place.
  */
 /*
  * For now, map all interrupts to IP[2].  We could save
@@ -167,10 +212,10 @@
  * 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. 
- * 
+ * 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 
+ * 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
  */
@@ -178,12 +223,16 @@
 #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 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 < NR_IRQS; i++) {	/* was I0 */
@@ -220,26 +269,60 @@
 	out64(tmp, KSEG1 + A_IMR_REGISTER(0, R_IMR_INTERRUPT_MASK));
 	out64(tmp, KSEG1 + 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 
+	 * Note that the timer interrupts are also mapped, but this is
 	 * done in sb1250_time_init()
 	 */
 
-#ifdef CONFIG_SIBYTE_SB1250_PROF
-	/* Enable IP[7,4:0], disable the rest */
-	clear_cp0_status(0x6000);
-	set_cp0_status(0x9f00);
-#else
-	/* Enable IP[4:0], disable the rest */
-	clear_cp0_status(0xe000);
-	set_cp0_status(0x1f00);
+#ifdef CONFIG_BCM1250_PROF
+	imask |= STATUSF_IP7;
+#endif
+#ifdef CONFIG_REMOTE_DEBUG
+	imask |= STATUSF_IP6;
 #endif
+	/* Enable necessary IPs, disable the rest */
+	change_cp0_status(ST0_IM, imask);
 	set_except_vector(0, sb1250_irq_handler);
 
 #ifdef CONFIG_REMOTE_DEBUG
-	/* If local serial I/O used for debug port, enter kgdb at once */
-//      puts("Waiting for kgdb to connect...");
-	set_debug_traps();
-	breakpoint();
+	if (kgdb_flag) {
+		/* Setup uart 1 settings, mapper */
+		out64(M_DUART_IMR_BRK, KSEG1 + A_DUART + R_DUART_IMR_B);
+
+		out64(IMR_IP6_VAL,
+			KSEG1 + A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) + (K_INT_UART_1<<3));
+		tmp = in64(KSEG1 + A_IMR_REGISTER(0, R_IMR_INTERRUPT_MASK));
+		tmp &= ~(1<<K_INT_UART_1);
+		out64(tmp, KSEG1 + A_IMR_REGISTER(0, R_IMR_INTERRUPT_MASK));
+
+		set_debug_traps();
+		breakpoint();
+	}
 #endif
 }
+
+#ifdef CONFIG_REMOTE_DEBUG
+
+#include <linux/delay.h>
+
+extern void set_async_breakpoint(unsigned int epc);
+
+#define duart_out(reg, val)     out64(val, KSEG1 + A_DUART_CHANREG(1,reg))
+#define duart_in(reg)           in64(KSEG1 + A_DUART_CHANREG(1,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)
+	 */
+	mdelay(500);
+	duart_out(R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT |
+				M_DUART_RX_EN | M_DUART_TX_EN);
+	if (!user_mode(regs))
+		set_async_breakpoint(regs->cp0_epc);
+}
+#endif 	/* CONFIG_REMOTE_DEBUG */