X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fmips%2Fkernel%2Fgdb-stub.c;h=6ecbdc1fefd13acdd930998a07c19e633aaab354;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=269889302a27d786c101d6d2da754351607b91c3;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/arch/mips/kernel/gdb-stub.c b/arch/mips/kernel/gdb-stub.c
index 269889302..6ecbdc1fe 100644
--- a/arch/mips/kernel/gdb-stub.c
+++ b/arch/mips/kernel/gdb-stub.c
@@ -140,6 +140,7 @@
 #include <asm/system.h>
 #include <asm/gdb-stub.h>
 #include <asm/inst.h>
+#include <asm/smp.h>
 
 /*
  * external low-level support routines
@@ -176,8 +177,10 @@ int kgdb_enabled;
 /*
  * spin locks for smp case
  */
-static spinlock_t kgdb_lock = SPIN_LOCK_UNLOCKED;
-static spinlock_t kgdb_cpulock[NR_CPUS] = { [0 ... NR_CPUS-1] = SPIN_LOCK_UNLOCKED};
+static DEFINE_SPINLOCK(kgdb_lock);
+static raw_spinlock_t kgdb_cpulock[NR_CPUS] = {
+	[0 ... NR_CPUS-1] = __RAW_SPIN_LOCK_UNLOCKED,
+};
 
 /*
  * BUFMAX defines the maximum number of characters in inbound/outbound buffers
@@ -637,33 +640,94 @@ static struct gdb_bp_save async_bp;
  * and only one can be active at a time.
  */
 extern spinlock_t smp_call_lock;
+
 void set_async_breakpoint(unsigned long *epc)
 {
 	/* skip breaking into userland */
 	if ((*epc & 0x80000000) == 0)
 		return;
 
+#ifdef CONFIG_SMP
 	/* avoid deadlock if someone is make IPC */
 	if (spin_is_locked(&smp_call_lock))
 		return;
+#endif
 
 	async_bp.addr = *epc;
 	*epc = (unsigned long)async_breakpoint;
 }
 
-void kgdb_wait(void *arg)
+static void kgdb_wait(void *arg)
 {
 	unsigned flags;
 	int cpu = smp_processor_id();
 
 	local_irq_save(flags);
 
-	spin_lock(&kgdb_cpulock[cpu]);
-	spin_unlock(&kgdb_cpulock[cpu]);
+	__raw_spin_lock(&kgdb_cpulock[cpu]);
+	__raw_spin_unlock(&kgdb_cpulock[cpu]);
 
 	local_irq_restore(flags);
 }
 
+/*
+ * GDB stub needs to call kgdb_wait on all processor with interrupts
+ * disabled, so it uses it's own special variant.
+ */
+static int kgdb_smp_call_kgdb_wait(void)
+{
+#ifdef CONFIG_SMP
+	struct call_data_struct data;
+	int i, cpus = num_online_cpus() - 1;
+	int cpu = smp_processor_id();
+
+	/*
+	 * Can die spectacularly if this CPU isn't yet marked online
+	 */
+	BUG_ON(!cpu_online(cpu));
+
+	if (!cpus)
+		return 0;
+
+	if (spin_is_locked(&smp_call_lock)) {
+		/*
+		 * Some other processor is trying to make us do something
+		 * but we're not going to respond... give up
+		 */
+		return -1;
+		}
+
+	/*
+	 * We will continue here, accepting the fact that
+	 * the kernel may deadlock if another CPU attempts
+	 * to call smp_call_function now...
+	 */
+
+	data.func = kgdb_wait;
+	data.info = NULL;
+	atomic_set(&data.started, 0);
+	data.wait = 0;
+
+	spin_lock(&smp_call_lock);
+	call_data = &data;
+	mb();
+
+	/* Send a message to all other CPUs and wait for them to respond */
+	for (i = 0; i < NR_CPUS; i++)
+		if (cpu_online(i) && i != cpu)
+			core_send_ipi(i, SMP_CALL_FUNCTION);
+
+	/* Wait for response */
+	/* FIXME: lock-up detection, backtrace on lock-up */
+	while (atomic_read(&data.started) != cpus)
+		barrier();
+
+	call_data = NULL;
+	spin_unlock(&smp_call_lock);
+#endif
+
+	return 0;
+}
 
 /*
  * This function does all command processing for interfacing to gdb.  It
@@ -687,8 +751,8 @@ void handle_exception (struct gdb_regs *regs)
 	 * acquire the big kgdb spinlock
 	 */
 	if (!spin_trylock(&kgdb_lock)) {
-		/* 
-		 * some other CPU has the lock, we should go back to 
+		/*
+		 * some other CPU has the lock, we should go back to
 		 * receive the gdb_wait IPC
 		 */
 		return;
@@ -703,17 +767,17 @@ void handle_exception (struct gdb_regs *regs)
 		async_bp.addr = 0;
 	}
 
-	/* 
+	/*
 	 * acquire the CPU spinlocks
 	 */
 	for (i = num_online_cpus()-1; i >= 0; i--)
-		if (spin_trylock(&kgdb_cpulock[i]) == 0)
+		if (__raw_spin_trylock(&kgdb_cpulock[i]) == 0)
 			panic("kgdb: couldn't get cpulock %d\n", i);
 
 	/*
 	 * force other cpus to enter kgdb
 	 */
-	smp_call_function(kgdb_wait, NULL, 0, 0);
+	kgdb_smp_call_kgdb_wait();
 
 	/*
 	 * If we're in breakpoint() increment the PC
@@ -894,7 +958,7 @@ void handle_exception (struct gdb_regs *regs)
 			ptr = &input_buffer[1];
 			if (hexToLong(&ptr, &addr))
 				regs->cp0_epc = addr;
-	  
+
 			goto exit_kgdb_exception;
 			break;
 
@@ -982,7 +1046,7 @@ finish_kgdb:
 exit_kgdb_exception:
 	/* release locks so other CPUs can go */
 	for (i = num_online_cpus()-1; i >= 0; i--)
-		spin_unlock(&kgdb_cpulock[i]);
+		__raw_spin_unlock(&kgdb_cpulock[i]);
 	spin_unlock(&kgdb_lock);
 
 	__flush_cache_all();
@@ -1001,7 +1065,7 @@ void breakpoint(void)
 		return;
 
 	__asm__ __volatile__(
-			".globl	breakinst\n\t" 
+			".globl	breakinst\n\t"
 			".set\tnoreorder\n\t"
 			"nop\n"
 			"breakinst:\tbreak\n\t"
@@ -1014,7 +1078,7 @@ void breakpoint(void)
 void async_breakpoint(void)
 {
 	__asm__ __volatile__(
-			".globl	async_breakinst\n\t" 
+			".globl	async_breakinst\n\t"
 			".set\tnoreorder\n\t"
 			"nop\n"
 			"async_breakinst:\tbreak\n\t"
@@ -1036,12 +1100,12 @@ void adel(void)
  * malloc is needed by gdb client in "call func()", even a private one
  * will make gdb happy
  */
-static void *malloc(size_t size)
+static void * __attribute_used__ malloc(size_t size)
 {
 	return kmalloc(size, GFP_ATOMIC);
 }
 
-static void free(void *where)
+static void __attribute_used__ free (void *where)
 {
 	kfree(where);
 }