Date: Sat, 11 Mar 2017 22:22:51 +0000 (UTC) From: Ian Lepore <ian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r315089 - head/share/man/man9 Message-ID: <201703112222.v2BMMpCR091563@repo.freebsd.org>
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Author: ian Date: Sat Mar 11 22:22:51 2017 New Revision: 315089 URL: https://svnweb.freebsd.org/changeset/base/315089 Log: Document uiomove_frombuf(9). Modified: head/share/man/man9/Makefile head/share/man/man9/uio.9 Modified: head/share/man/man9/Makefile ============================================================================== --- head/share/man/man9/Makefile Sat Mar 11 20:28:31 2017 (r315088) +++ head/share/man/man9/Makefile Sat Mar 11 22:22:51 2017 (r315089) @@ -1843,6 +1843,7 @@ MLINKS+=uidinfo.9 uifind.9 \ uidinfo.9 uihashinit.9 \ uidinfo.9 uihold.9 MLINKS+=uio.9 uiomove.9 \ + uio.9 uiomove_frombuf.9 \ uio.9 uiomove_nofault.9 .if ${MK_USB} != "no" Modified: head/share/man/man9/uio.9 ============================================================================== --- head/share/man/man9/uio.9 Sat Mar 11 20:28:31 2017 (r315088) +++ head/share/man/man9/uio.9 Sat Mar 11 22:22:51 2017 (r315089) @@ -25,12 +25,13 @@ .\" .\" $FreeBSD$ .\" -.Dd January 19, 2012 +.Dd March 11, 2017 .Dt UIO 9 .Os .Sh NAME .Nm uio , .Nm uiomove , +.Nm uiomove_frombuf , .Nm uiomove_nofault .Nd device driver I/O routines .Sh SYNOPSIS @@ -50,10 +51,13 @@ struct uio { .Ft int .Fn uiomove "void *buf" "int howmuch" "struct uio *uiop" .Ft int +.Fn uiomove_frombuf "void *buf" "int howmuch" "struct uio *uiop" +.Ft int .Fn uiomove_nofault "void *buf" "int howmuch" "struct uio *uiop" .Sh DESCRIPTION The functions -.Fn uiomove +.Fn uiomove , +.Fn uiomove_frombuf , and .Fn uiomove_nofault are used to transfer data between buffers and I/O vectors that might @@ -129,9 +133,27 @@ Thus, the function .Fn uiomove_nofault can be called from contexts where acquiring virtual memory system locks or sleeping are prohibited. +.Pp +The +.Fn uiomove_frombuf +function is a convenience wrapper around +.Fn uiomove +for drivers that serve data which is wholly contained within an +existing buffer in memory. +It validates the +.Va uio_offset +and +.Va uio_resid +values against the size of the existing buffer, handling short +transfers when the request partially overlaps the buffer. +When +.Va uio_offset +is greater than or equal to the buffer size, the result is success +with no bytes transfered, effectively signaling EOF. .Sh RETURN VALUES On success -.Fn uiomove +.Fn uiomove , +.Fn uiomove_frombuf , and .Fn uiomove_nofault will return 0; on error they will return an appropriate error code.
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