patch-2.3.51 linux/arch/ia64/lib/copy_user.S

• Lines: 35
• Date: Fri Mar 10 15:24:02 2000
• Orig file: v2.3.50/linux/arch/ia64/lib/copy_user.S
• Orig date: Sat Feb 26 22:31:39 2000

diff -u --recursive --new-file v2.3.50/linux/arch/ia64/lib/copy_user.S linux/arch/ia64/lib/copy_user.S
@@ -1,3 +1,34 @@
+/*
+ *
+ * Optimized version of the copy_user() routine.
+ * It is used to copy date across the kernel/user boundary.
+ *
+ * The source and destination are always on opposite side of
+ * the boundary. When reading from user space we must catch
+ * faults on loads. When writing to user space we must catch
+ * errors on stores. Note that because of the nature of the copy
+ * we don't need to worry about overlapping regions.
+ *
+ *
+ * Inputs:
+ *	in0	address of source buffer
+ * 	in1	address of destination buffer
+ *	in2	number of bytes to copy
+ *
+ * Outputs: 
+ * 	ret0	0 in case of sucess. The number of bytes NOT copied in
+ * 		case of error.
+ *
+ * Copyright (C) 2000 Hewlett-Packard Co
+ * Copyright (C) 2000 Stephane Eranian <eranian@hpl.hp.com>
+ *
+ * Fixme:
+ *	- handle the case where we have more than 16 bytes and the alignment
+ * 	  are different.
+ *	- more benchmarking
+ * 	- fix extraneous stop bit introduced by the EX() macro.
+ */
+
 // The label comes first because our store instruction contains a comma
 // and confuse the preprocessor otherwise
 //