linux/drivers/xen/xen-pciback/conf_space.c
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

432 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* PCI Backend - Functions for creating a virtual configuration space for
* exported PCI Devices.
* It's dangerous to allow PCI Driver Domains to change their
* device's resources (memory, i/o ports, interrupts). We need to
* restrict changes to certain PCI Configuration registers:
* BARs, INTERRUPT_PIN, most registers in the header...
*
* Author: Ryan Wilson <hap9@epoch.ncsc.mil>
*/
#include <linux/kernel.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include "pciback.h"
#include "conf_space.h"
#include "conf_space_quirks.h"
bool xen_pcibk_permissive;
module_param_named(permissive, xen_pcibk_permissive, bool, 0644);
/* This is where xen_pcibk_read_config_byte, xen_pcibk_read_config_word,
* xen_pcibk_write_config_word, and xen_pcibk_write_config_byte are created. */
#define DEFINE_PCI_CONFIG(op, size, type) \
int xen_pcibk_##op##_config_##size \
(struct pci_dev *dev, int offset, type value, void *data) \
{ \
return pci_##op##_config_##size(dev, offset, value); \
}
DEFINE_PCI_CONFIG(read, byte, u8 *)
DEFINE_PCI_CONFIG(read, word, u16 *)
DEFINE_PCI_CONFIG(read, dword, u32 *)
DEFINE_PCI_CONFIG(write, byte, u8)
DEFINE_PCI_CONFIG(write, word, u16)
DEFINE_PCI_CONFIG(write, dword, u32)
static int conf_space_read(struct pci_dev *dev,
const struct config_field_entry *entry,
int offset, u32 *value)
{
int ret = 0;
const struct config_field *field = entry->field;
*value = 0;
switch (field->size) {
case 1:
if (field->u.b.read)
ret = field->u.b.read(dev, offset, (u8 *) value,
entry->data);
break;
case 2:
if (field->u.w.read)
ret = field->u.w.read(dev, offset, (u16 *) value,
entry->data);
break;
case 4:
if (field->u.dw.read)
ret = field->u.dw.read(dev, offset, value, entry->data);
break;
}
return ret;
}
static int conf_space_write(struct pci_dev *dev,
const struct config_field_entry *entry,
int offset, u32 value)
{
int ret = 0;
const struct config_field *field = entry->field;
switch (field->size) {
case 1:
if (field->u.b.write)
ret = field->u.b.write(dev, offset, (u8) value,
entry->data);
break;
case 2:
if (field->u.w.write)
ret = field->u.w.write(dev, offset, (u16) value,
entry->data);
break;
case 4:
if (field->u.dw.write)
ret = field->u.dw.write(dev, offset, value,
entry->data);
break;
}
return ret;
}
static inline u32 get_mask(int size)
{
if (size == 1)
return 0xff;
else if (size == 2)
return 0xffff;
else
return 0xffffffff;
}
static inline int valid_request(int offset, int size)
{
/* Validate request (no un-aligned requests) */
if ((size == 1 || size == 2 || size == 4) && (offset % size) == 0)
return 1;
return 0;
}
static inline u32 merge_value(u32 val, u32 new_val, u32 new_val_mask,
int offset)
{
if (offset >= 0) {
new_val_mask <<= (offset * 8);
new_val <<= (offset * 8);
} else {
new_val_mask >>= (offset * -8);
new_val >>= (offset * -8);
}
val = (val & ~new_val_mask) | (new_val & new_val_mask);
return val;
}
static int xen_pcibios_err_to_errno(int err)
{
switch (err) {
case PCIBIOS_SUCCESSFUL:
return XEN_PCI_ERR_success;
case PCIBIOS_DEVICE_NOT_FOUND:
return XEN_PCI_ERR_dev_not_found;
case PCIBIOS_BAD_REGISTER_NUMBER:
return XEN_PCI_ERR_invalid_offset;
case PCIBIOS_FUNC_NOT_SUPPORTED:
return XEN_PCI_ERR_not_implemented;
case PCIBIOS_SET_FAILED:
return XEN_PCI_ERR_access_denied;
}
return err;
}
int xen_pcibk_config_read(struct pci_dev *dev, int offset, int size,
u32 *ret_val)
{
int err = 0;
struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
const struct config_field_entry *cfg_entry;
const struct config_field *field;
int field_start, field_end;
/* if read fails for any reason, return 0
* (as if device didn't respond) */
u32 value = 0, tmp_val;
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: read %d bytes at 0x%x\n",
pci_name(dev), size, offset);
if (!valid_request(offset, size)) {
err = XEN_PCI_ERR_invalid_offset;
goto out;
}
/* Get the real value first, then modify as appropriate */
switch (size) {
case 1:
err = pci_read_config_byte(dev, offset, (u8 *) &value);
break;
case 2:
err = pci_read_config_word(dev, offset, (u16 *) &value);
break;
case 4:
err = pci_read_config_dword(dev, offset, &value);
break;
}
list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
field = cfg_entry->field;
field_start = OFFSET(cfg_entry);
field_end = OFFSET(cfg_entry) + field->size;
if (offset + size > field_start && field_end > offset) {
err = conf_space_read(dev, cfg_entry, field_start,
&tmp_val);
if (err)
goto out;
value = merge_value(value, tmp_val,
get_mask(field->size),
field_start - offset);
}
}
out:
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: read %d bytes at 0x%x = %x\n",
pci_name(dev), size, offset, value);
*ret_val = value;
return xen_pcibios_err_to_errno(err);
}
int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value)
{
int err = 0, handled = 0;
struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
const struct config_field_entry *cfg_entry;
const struct config_field *field;
u32 tmp_val;
int field_start, field_end;
if (unlikely(verbose_request))
printk(KERN_DEBUG
DRV_NAME ": %s: write request %d bytes at 0x%x = %x\n",
pci_name(dev), size, offset, value);
if (!valid_request(offset, size))
return XEN_PCI_ERR_invalid_offset;
list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
field = cfg_entry->field;
field_start = OFFSET(cfg_entry);
field_end = OFFSET(cfg_entry) + field->size;
if (offset + size > field_start && field_end > offset) {
err = conf_space_read(dev, cfg_entry, field_start,
&tmp_val);
if (err)
break;
tmp_val = merge_value(tmp_val, value, get_mask(size),
offset - field_start);
err = conf_space_write(dev, cfg_entry, field_start,
tmp_val);
/* handled is set true here, but not every byte
* may have been written! Properly detecting if
* every byte is handled is unnecessary as the
* flag is used to detect devices that need
* special helpers to work correctly.
*/
handled = 1;
}
}
if (!handled && !err) {
/* By default, anything not specificially handled above is
* read-only. The permissive flag changes this behavior so
* that anything not specifically handled above is writable.
* This means that some fields may still be read-only because
* they have entries in the config_field list that intercept
* the write and do nothing. */
if (dev_data->permissive || xen_pcibk_permissive) {
switch (size) {
case 1:
err = pci_write_config_byte(dev, offset,
(u8) value);
break;
case 2:
err = pci_write_config_word(dev, offset,
(u16) value);
break;
case 4:
err = pci_write_config_dword(dev, offset,
(u32) value);
break;
}
} else if (!dev_data->warned_on_write) {
dev_data->warned_on_write = 1;
dev_warn(&dev->dev, "Driver tried to write to a "
"read-only configuration space field at offset"
" 0x%x, size %d. This may be harmless, but if "
"you have problems with your device:\n"
"1) see permissive attribute in sysfs\n"
"2) report problems to the xen-devel "
"mailing list along with details of your "
"device obtained from lspci.\n", offset, size);
}
}
return xen_pcibios_err_to_errno(err);
}
void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev)
{
struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
struct config_field_entry *cfg_entry, *t;
const struct config_field *field;
dev_dbg(&dev->dev, "free-ing dynamically allocated virtual "
"configuration space fields\n");
if (!dev_data)
return;
list_for_each_entry_safe(cfg_entry, t, &dev_data->config_fields, list) {
field = cfg_entry->field;
if (field->clean) {
field->clean((struct config_field *)field);
kfree(cfg_entry->data);
list_del(&cfg_entry->list);
kfree(cfg_entry);
}
}
}
void xen_pcibk_config_reset_dev(struct pci_dev *dev)
{
struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
const struct config_field_entry *cfg_entry;
const struct config_field *field;
dev_dbg(&dev->dev, "resetting virtual configuration space\n");
if (!dev_data)
return;
list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
field = cfg_entry->field;
if (field->reset)
field->reset(dev, OFFSET(cfg_entry), cfg_entry->data);
}
}
void xen_pcibk_config_free_dev(struct pci_dev *dev)
{
struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
struct config_field_entry *cfg_entry, *t;
const struct config_field *field;
dev_dbg(&dev->dev, "free-ing virtual configuration space fields\n");
if (!dev_data)
return;
list_for_each_entry_safe(cfg_entry, t, &dev_data->config_fields, list) {
list_del(&cfg_entry->list);
field = cfg_entry->field;
if (field->release)
field->release(dev, OFFSET(cfg_entry), cfg_entry->data);
kfree(cfg_entry);
}
}
int xen_pcibk_config_add_field_offset(struct pci_dev *dev,
const struct config_field *field,
unsigned int base_offset)
{
int err = 0;
struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
struct config_field_entry *cfg_entry;
void *tmp;
cfg_entry = kmalloc(sizeof(*cfg_entry), GFP_KERNEL);
if (!cfg_entry) {
err = -ENOMEM;
goto out;
}
cfg_entry->data = NULL;
cfg_entry->field = field;
cfg_entry->base_offset = base_offset;
/* silently ignore duplicate fields */
err = xen_pcibk_field_is_dup(dev, OFFSET(cfg_entry));
if (err)
goto out;
if (field->init) {
tmp = field->init(dev, OFFSET(cfg_entry));
if (IS_ERR(tmp)) {
err = PTR_ERR(tmp);
goto out;
}
cfg_entry->data = tmp;
}
dev_dbg(&dev->dev, "added config field at offset 0x%02x\n",
OFFSET(cfg_entry));
list_add_tail(&cfg_entry->list, &dev_data->config_fields);
out:
if (err)
kfree(cfg_entry);
return err;
}
/* This sets up the device's virtual configuration space to keep track of
* certain registers (like the base address registers (BARs) so that we can
* keep the client from manipulating them directly.
*/
int xen_pcibk_config_init_dev(struct pci_dev *dev)
{
int err = 0;
struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
dev_dbg(&dev->dev, "initializing virtual configuration space\n");
INIT_LIST_HEAD(&dev_data->config_fields);
err = xen_pcibk_config_header_add_fields(dev);
if (err)
goto out;
err = xen_pcibk_config_capability_add_fields(dev);
if (err)
goto out;
err = xen_pcibk_config_quirks_init(dev);
out:
return err;
}
int xen_pcibk_config_init(void)
{
return xen_pcibk_config_capability_init();
}