Merge branch 'master' into next

Conflicts:
	fs/namei.c

Manually merged per:

diff --cc fs/namei.c
index 734f2b5,bbc15c2..0000000
--- a/fs/namei.c
+++ b/fs/namei.c
@@@ -860,9 -848,8 +849,10 @@@ static int __link_path_walk(const char
  		nd->flags |= LOOKUP_CONTINUE;
  		err = exec_permission_lite(inode);
  		if (err == -EAGAIN)
- 			err = vfs_permission(nd, MAY_EXEC);
+ 			err = inode_permission(nd->path.dentry->d_inode,
+ 					       MAY_EXEC);
 +		if (!err)
 +			err = ima_path_check(&nd->path, MAY_EXEC);
   		if (err)
  			break;

@@@ -1525,14 -1506,9 +1509,14 @@@ int may_open(struct path *path, int acc
  		flag &= ~O_TRUNC;
  	}

- 	error = vfs_permission(nd, acc_mode);
+ 	error = inode_permission(inode, acc_mode);
  	if (error)
  		return error;
 +
- 	error = ima_path_check(&nd->path,
++	error = ima_path_check(path,
 +			       acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC));
 +	if (error)
 +		return error;
  	/*
  	 * An append-only file must be opened in append mode for writing.
  	 */

Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 187 insertions, 2 deletions

diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl
index df87d1b93605..52e1b79ce0e6 100644
--- a/Documentation/DocBook/uio-howto.tmpl
+++ b/Documentation/DocBook/uio-howto.tmpl
@@ -42,6 +42,18 @@ GPL version 2.
 
 <revhistory>
 	<revision>
+	<revnumber>0.7</revnumber>
+	<date>2008-12-23</date>
+	<authorinitials>hjk</authorinitials>
+	<revremark>Added generic platform drivers and offset attribute.</revremark>
+	</revision>
+	<revision>
+	<revnumber>0.6</revnumber>
+	<date>2008-12-05</date>
+	<authorinitials>hjk</authorinitials>
+	<revremark>Added description of portio sysfs attributes.</revremark>
+	</revision>
+	<revision>
 	<revnumber>0.5</revnumber>
 	<date>2008-05-22</date>
 	<authorinitials>hjk</authorinitials>
@@ -306,6 +318,16 @@ interested in translating it, please email me
 	pointed to by addr.
 	</para>
 </listitem>
+<listitem>
+	<para>
+	<filename>offset</filename>: The offset, in bytes, that has to be
+	added to the pointer returned by <function>mmap()</function> to get
+	to the actual device memory. This is important if the device's memory
+	is not page aligned. Remember that pointers returned by
+	<function>mmap()</function> are always page aligned, so it is good
+	style to always add this offset.
+	</para>
+</listitem>
 </itemizedlist>
 
 <para>
@@ -318,6 +340,54 @@ interested in translating it, please email me
 offset = N * getpagesize();
 </programlisting>
 
+<para>
+	Sometimes there is hardware with memory-like regions that can not be
+	mapped with the technique described here, but there are still ways to
+	access them from userspace. The most common example are x86 ioports.
+	On x86 systems, userspace can access these ioports using
+	<function>ioperm()</function>, <function>iopl()</function>,
+	<function>inb()</function>, <function>outb()</function>, and similar
+	functions.
+</para>
+<para>
+	Since these ioport regions can not be mapped, they will not appear under
+	<filename>/sys/class/uio/uioX/maps/</filename> like the normal memory
+	described above. Without information about the port regions a hardware
+	has to offer, it becomes difficult for the userspace part of the
+	driver to find out which ports belong to which UIO device.
+</para>
+<para>
+	To address this situation, the new directory
+	<filename>/sys/class/uio/uioX/portio/</filename> was added. It only
+	exists if the driver wants to pass information about one or more port
+	regions to userspace. If that is the case, subdirectories named
+	<filename>port0</filename>, <filename>port1</filename>, and so on,
+	will appear underneath
+	<filename>/sys/class/uio/uioX/portio/</filename>.
+</para>
+<para>
+	Each <filename>portX/</filename> directory contains three read-only
+	files that show start, size, and type of the port region:
+</para>
+<itemizedlist>
+<listitem>
+	<para>
+	<filename>start</filename>: The first port of this region.
+	</para>
+</listitem>
+<listitem>
+	<para>
+	<filename>size</filename>: The number of ports in this region.
+	</para>
+</listitem>
+<listitem>
+	<para>
+	<filename>porttype</filename>: A string describing the type of port.
+	</para>
+</listitem>
+</itemizedlist>
+
+
 </sect1>
 </chapter>
 
@@ -339,12 +409,12 @@ offset = N * getpagesize();
 
 <itemizedlist>
 <listitem><para>
-<varname>char *name</varname>: Required. The name of your driver as
+<varname>const char *name</varname>: Required. The name of your driver as
 it will appear in sysfs. I recommend using the name of your module for this.
 </para></listitem>
 
 <listitem><para>
-<varname>char *version</varname>: Required. This string appears in
+<varname>const char *version</varname>: Required. This string appears in
 <filename>/sys/class/uio/uioX/version</filename>.
 </para></listitem>
 
@@ -356,6 +426,13 @@ See the description below for details.
 </para></listitem>
 
 <listitem><para>
+<varname>struct uio_port port[ MAX_UIO_PORTS_REGIONS ]</varname>: Required
+if you want to pass information about ioports to userspace. For each port
+region you need to fill one of the <varname>uio_port</varname> structures.
+See the description below for details.
+</para></listitem>
+
+<listitem><para>
 <varname>long irq</varname>: Required. If your hardware generates an
 interrupt, it's your modules task to determine the irq number during
 initialization. If you don't have a hardware generated interrupt but
@@ -448,6 +525,42 @@ Please do not touch the <varname>kobj</varname> element of
 <varname>struct uio_mem</varname>! It is used by the UIO framework
 to set up sysfs files for this mapping. Simply leave it alone.
 </para>
+
+<para>
+Sometimes, your device can have one or more port regions which can not be
+mapped to userspace. But if there are other possibilities for userspace to
+access these ports, it makes sense to make information about the ports
+available in sysfs. For each region, you have to set up a
+<varname>struct uio_port</varname> in the <varname>port[]</varname> array.
+Here's a description of the fields of <varname>struct uio_port</varname>:
+</para>
+
+<itemizedlist>
+<listitem><para>
+<varname>char *porttype</varname>: Required. Set this to one of the predefined
+constants. Use <varname>UIO_PORT_X86</varname> for the ioports found in x86
+architectures.
+</para></listitem>
+
+<listitem><para>
+<varname>unsigned long start</varname>: Required if the port region is used.
+Fill in the number of the first port of this region.
+</para></listitem>
+
+<listitem><para>
+<varname>unsigned long size</varname>: Fill in the number of ports in this
+region. If <varname>size</varname> is zero, the region is considered unused.
+Note that you <emphasis>must</emphasis> initialize <varname>size</varname>
+with zero for all unused regions.
+</para></listitem>
+</itemizedlist>
+
+<para>
+Please do not touch the <varname>portio</varname> element of
+<varname>struct uio_port</varname>! It is used internally by the UIO
+framework to set up sysfs files for this region. Simply leave it alone.
+</para>
+
 </sect1>
 
 <sect1 id="adding_irq_handler">
@@ -497,6 +610,78 @@ to set up sysfs files for this mapping. Simply leave it alone.
 	</para>
 </sect1>
 
+<sect1 id="using_uio_pdrv">
+<title>Using uio_pdrv for platform devices</title>
+	<para>
+	In many cases, UIO drivers for platform devices can be handled in a
+	generic way. In the same place where you define your
+	<varname>struct platform_device</varname>, you simply also implement
+	your interrupt handler and fill your
+	<varname>struct uio_info</varname>. A pointer to this
+	<varname>struct uio_info</varname> is then used as
+	<varname>platform_data</varname> for your platform device.
+	</para>
+	<para>
+	You also need to set up an array of <varname>struct resource</varname>
+	containing addresses and sizes of your memory mappings. This
+	information is passed to the driver using the
+	<varname>.resource</varname> and <varname>.num_resources</varname>
+	elements of <varname>struct platform_device</varname>.
+	</para>
+	<para>
+	You now have to set the <varname>.name</varname> element of
+	<varname>struct platform_device</varname> to
+	<varname>"uio_pdrv"</varname> to use the generic UIO platform device
+	driver. This driver will fill the <varname>mem[]</varname> array
+	according to the resources given, and register the device.
+	</para>
+	<para>
+	The advantage of this approach is that you only have to edit a file
+	you need to edit anyway. You do not have to create an extra driver.
+	</para>
+</sect1>
+
+<sect1 id="using_uio_pdrv_genirq">
+<title>Using uio_pdrv_genirq for platform devices</title>
+	<para>
+	Especially in embedded devices, you frequently find chips where the
+	irq pin is tied to its own dedicated interrupt line. In such cases,
+	where you can be really sure the interrupt is not shared, we can take
+	the concept of <varname>uio_pdrv</varname> one step further and use a
+	generic interrupt handler. That's what
+	<varname>uio_pdrv_genirq</varname> does.
+	</para>
+	<para>
+	The setup for this driver is the same as described above for
+	<varname>uio_pdrv</varname>, except that you do not implement an
+	interrupt handler. The <varname>.handler</varname> element of
+	<varname>struct uio_info</varname> must remain
+	<varname>NULL</varname>. The  <varname>.irq_flags</varname> element
+	must not contain <varname>IRQF_SHARED</varname>.
+	</para>
+	<para>
+	You will set the <varname>.name</varname> element of
+	<varname>struct platform_device</varname> to
+	<varname>"uio_pdrv_genirq"</varname> to use this driver.
+	</para>
+	<para>
+	The generic interrupt handler of <varname>uio_pdrv_genirq</varname>
+	will simply disable the interrupt line using
+	<function>disable_irq_nosync()</function>. After doing its work,
+	userspace can reenable the interrupt by writing 0x00000001 to the UIO
+	device file. The driver already implements an
+	<function>irq_control()</function> to make this possible, you must not
+	implement your own.
+	</para>
+	<para>
+	Using <varname>uio_pdrv_genirq</varname> not only saves a few lines of
+	interrupt handler code. You also do not need to know anything about
+	the chip's internal registers to create the kernel part of the driver.
+	All you need to know is the irq number of the pin the chip is
+	connected to.
+	</para>
+</sect1>
+
 </chapter>
 
 <chapter id="userspace_driver" xreflabel="Writing a driver in user space">