linux/drivers/usb/gadget/config.c

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/*
* usb/gadget/config.c -- simplify building config descriptors
*
* Copyright (C) 2003 David Brownell
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/errno.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
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#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/string.h>
#include <linux/device.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
/**
* usb_descriptor_fillbuf - fill buffer with descriptors
* @buf: Buffer to be filled
* @buflen: Size of buf
* @src: Array of descriptor pointers, terminated by null pointer.
*
* Copies descriptors into the buffer, returning the length or a
* negative error code if they can't all be copied. Useful when
* assembling descriptors for an associated set of interfaces used
* as part of configuring a composite device; or in other cases where
* sets of descriptors need to be marshaled.
*/
int
usb_descriptor_fillbuf(void *buf, unsigned buflen,
const struct usb_descriptor_header **src)
{
u8 *dest = buf;
if (!src)
return -EINVAL;
/* fill buffer from src[] until null descriptor ptr */
for (; NULL != *src; src++) {
unsigned len = (*src)->bLength;
if (len > buflen)
return -EINVAL;
memcpy(dest, *src, len);
buflen -= len;
dest += len;
}
return dest - (u8 *)buf;
}
/**
* usb_gadget_config_buf - builts a complete configuration descriptor
* @config: Header for the descriptor, including characteristics such
* as power requirements and number of interfaces.
* @desc: Null-terminated vector of pointers to the descriptors (interface,
* endpoint, etc) defining all functions in this device configuration.
* @buf: Buffer for the resulting configuration descriptor.
* @length: Length of buffer. If this is not big enough to hold the
* entire configuration descriptor, an error code will be returned.
*
* This copies descriptors into the response buffer, building a descriptor
* for that configuration. It returns the buffer length or a negative
* status code. The config.wTotalLength field is set to match the length
* of the result, but other descriptor fields (including power usage and
* interface count) must be set by the caller.
*
* Gadget drivers could use this when constructing a config descriptor
* in response to USB_REQ_GET_DESCRIPTOR. They will need to patch the
* resulting bDescriptorType value if USB_DT_OTHER_SPEED_CONFIG is needed.
*/
int usb_gadget_config_buf(
const struct usb_config_descriptor *config,
void *buf,
unsigned length,
const struct usb_descriptor_header **desc
)
{
struct usb_config_descriptor *cp = buf;
int len;
/* config descriptor first */
if (length < USB_DT_CONFIG_SIZE || !desc)
return -EINVAL;
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*cp = *config;
/* then interface/endpoint/class/vendor/... */
len = usb_descriptor_fillbuf(USB_DT_CONFIG_SIZE + (u8*)buf,
length - USB_DT_CONFIG_SIZE, desc);
if (len < 0)
return len;
len += USB_DT_CONFIG_SIZE;
if (len > 0xffff)
return -EINVAL;
/* patch up the config descriptor */
cp->bLength = USB_DT_CONFIG_SIZE;
cp->bDescriptorType = USB_DT_CONFIG;
cp->wTotalLength = cpu_to_le16(len);
cp->bmAttributes |= USB_CONFIG_ATT_ONE;
return len;
}
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/**
* usb_copy_descriptors - copy a vector of USB descriptors
* @src: null-terminated vector to copy
* Context: initialization code, which may sleep
*
* This makes a copy of a vector of USB descriptors. Its primary use
* is to support usb_function objects which can have multiple copies,
* each needing different descriptors. Functions may have static
* tables of descriptors, which are used as templates and customized
* with identifiers (for interfaces, strings, endpoints, and more)
* as needed by a given function instance.
*/
struct usb_descriptor_header **
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usb_copy_descriptors(struct usb_descriptor_header **src)
{
struct usb_descriptor_header **tmp;
unsigned bytes;
unsigned n_desc;
void *mem;
struct usb_descriptor_header **ret;
/* count descriptors and their sizes; then add vector size */
for (bytes = 0, n_desc = 0, tmp = src; *tmp; tmp++, n_desc++)
bytes += (*tmp)->bLength;
bytes += (n_desc + 1) * sizeof(*tmp);
mem = kmalloc(bytes, GFP_KERNEL);
if (!mem)
return NULL;
/* fill in pointers starting at "tmp",
* to descriptors copied starting at "mem";
* and return "ret"
*/
tmp = mem;
ret = mem;
mem += (n_desc + 1) * sizeof(*tmp);
while (*src) {
memcpy(mem, *src, (*src)->bLength);
*tmp = mem;
tmp++;
mem += (*src)->bLength;
src++;
}
*tmp = NULL;
return ret;
}
/**
* usb_find_endpoint - find a copy of an endpoint descriptor
* @src: original vector of descriptors
* @copy: copy of @src
* @match: endpoint descriptor found in @src
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*
* This returns the copy of the @match descriptor made for @copy. Its
* intended use is to help remembering the endpoint descriptor to use
* when enabling a given endpoint.
*/
struct usb_endpoint_descriptor *
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usb_find_endpoint(
struct usb_descriptor_header **src,
struct usb_descriptor_header **copy,
struct usb_endpoint_descriptor *match
)
{
while (*src) {
if (*src == (void *) match)
return (void *)*copy;
src++;
copy++;
}
return NULL;
}