[IA64] fix SN2 hwperf error handling

Fix the error handling for the SN2 hardware perf ioctl interface.
Signed-off-by: Mark Goodwin <markgw@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/sn/kernel/sn2/sn_hwperf.c

@@ -3,7 +3,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2004 Silicon Graphics, Inc. All rights reserved.
+ * Copyright (C) 2004-2005 Silicon Graphics, Inc. All rights reserved.
  *
  * SGI Altix topology and hardware performance monitoring API.
  * Mark Goodwin <markgw@sgi.com>. 
@@ -374,6 +374,42 @@ static int sn_hwperf_op_cpu(struct sn_hwperf_op_info *op_info)
 	return r;
 }
 
+/* map SAL hwperf error code to system error code */
+static int sn_hwperf_map_err(int hwperf_err)
+{
+	int e;
+
+	switch(hwperf_err) {
+	case SN_HWPERF_OP_OK:
+		e = 0;
+		break;
+
+	case SN_HWPERF_OP_NOMEM:
+		e = -ENOMEM;
+		break;
+
+	case SN_HWPERF_OP_NO_PERM:
+		e = -EPERM;
+		break;
+
+	case SN_HWPERF_OP_IO_ERROR:
+		e = -EIO;
+		break;
+
+	case SN_HWPERF_OP_BUSY:
+	case SN_HWPERF_OP_RECONFIGURE:
+		e = -EAGAIN;
+		break;
+
+	case SN_HWPERF_OP_INVAL:
+	default:
+		e = -EINVAL;
+		break;
+	}
+
+	return e;
+}
+
 /*
  * ioctl for "sn_hwperf" misc device
  */
@@ -511,12 +547,20 @@ sn_hwperf_ioctl(struct inode *in, struct file *fp, u32 op, u64 arg)
 		op_info.v0 = &v0;
 		op_info.op = op;
 		r = sn_hwperf_op_cpu(&op_info);
+		if (r) {
+			r = sn_hwperf_map_err(r);
+			goto error;
+		}
 		break;
 
 	default:
 		/* all other ops are a direct SAL call */
 		r = ia64_sn_hwperf_op(sn_hwperf_master_nasid, op,
 			      a.arg, a.sz, (u64) p, 0, 0, &v0);
+		if (r) {
+			r = sn_hwperf_map_err(r);
+			goto error;
+		}
 		a.v0 = v0;
 		break;
 	}