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linux/drivers/xen/xen-pciback/pciback_ops.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

439 lines
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// SPDX-License-Identifier: GPL-2.0
/*
* PCI Backend Operations - respond to PCI requests from Frontend
*
* Author: Ryan Wilson <hap9@epoch.ncsc.mil>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/moduleparam.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <xen/events.h>
#include <linux/sched.h>
#include "pciback.h"
int verbose_request;
module_param(verbose_request, int, 0644);
static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id);
/* Ensure a device is has the fake IRQ handler "turned on/off" and is
* ready to be exported. This MUST be run after xen_pcibk_reset_device
* which does the actual PCI device enable/disable.
*/
static void xen_pcibk_control_isr(struct pci_dev *dev, int reset)
{
struct xen_pcibk_dev_data *dev_data;
int rc;
int enable = 0;
dev_data = pci_get_drvdata(dev);
if (!dev_data)
return;
/* We don't deal with bridges */
if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
return;
if (reset) {
dev_data->enable_intx = 0;
dev_data->ack_intr = 0;
}
enable = dev_data->enable_intx;
/* Asked to disable, but ISR isn't runnig */
if (!enable && !dev_data->isr_on)
return;
/* Squirrel away the IRQs in the dev_data. We need this
* b/c when device transitions to MSI, the dev->irq is
* overwritten with the MSI vector.
*/
if (enable)
dev_data->irq = dev->irq;
/*
* SR-IOV devices in all use MSI-X and have no legacy
* interrupts, so inhibit creating a fake IRQ handler for them.
*/
if (dev_data->irq == 0)
goto out;
dev_dbg(&dev->dev, "%s: #%d %s %s%s %s-> %s\n",
dev_data->irq_name,
dev_data->irq,
pci_is_enabled(dev) ? "on" : "off",
dev->msi_enabled ? "MSI" : "",
dev->msix_enabled ? "MSI/X" : "",
dev_data->isr_on ? "enable" : "disable",
enable ? "enable" : "disable");
if (enable) {
/*
* The MSI or MSI-X should not have an IRQ handler. Otherwise
* if the guest terminates we BUG_ON in free_msi_irqs.
*/
if (dev->msi_enabled || dev->msix_enabled)
goto out;
rc = request_irq(dev_data->irq,
xen_pcibk_guest_interrupt, IRQF_SHARED,
dev_data->irq_name, dev);
if (rc) {
dev_err(&dev->dev, "%s: failed to install fake IRQ " \
"handler for IRQ %d! (rc:%d)\n",
dev_data->irq_name, dev_data->irq, rc);
goto out;
}
} else {
free_irq(dev_data->irq, dev);
dev_data->irq = 0;
}
dev_data->isr_on = enable;
dev_data->ack_intr = enable;
out:
dev_dbg(&dev->dev, "%s: #%d %s %s%s %s\n",
dev_data->irq_name,
dev_data->irq,
pci_is_enabled(dev) ? "on" : "off",
dev->msi_enabled ? "MSI" : "",
dev->msix_enabled ? "MSI/X" : "",
enable ? (dev_data->isr_on ? "enabled" : "failed to enable") :
(dev_data->isr_on ? "failed to disable" : "disabled"));
}
/* Ensure a device is "turned off" and ready to be exported.
* (Also see xen_pcibk_config_reset to ensure virtual configuration space is
* ready to be re-exported)
*/
void xen_pcibk_reset_device(struct pci_dev *dev)
{
u16 cmd;
xen_pcibk_control_isr(dev, 1 /* reset device */);
/* Disable devices (but not bridges) */
if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL) {
#ifdef CONFIG_PCI_MSI
/* The guest could have been abruptly killed without
* disabling MSI/MSI-X interrupts.*/
if (dev->msix_enabled)
pci_disable_msix(dev);
if (dev->msi_enabled)
pci_disable_msi(dev);
#endif
if (pci_is_enabled(dev))
pci_disable_device(dev);
pci_write_config_word(dev, PCI_COMMAND, 0);
dev->is_busmaster = 0;
} else {
pci_read_config_word(dev, PCI_COMMAND, &cmd);
if (cmd & (PCI_COMMAND_INVALIDATE)) {
cmd &= ~(PCI_COMMAND_INVALIDATE);
pci_write_config_word(dev, PCI_COMMAND, cmd);
dev->is_busmaster = 0;
}
}
}
#ifdef CONFIG_PCI_MSI
static
int xen_pcibk_enable_msi(struct xen_pcibk_device *pdev,
struct pci_dev *dev, struct xen_pci_op *op)
{
struct xen_pcibk_dev_data *dev_data;
int status;
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: enable MSI\n", pci_name(dev));
if (dev->msi_enabled)
status = -EALREADY;
else if (dev->msix_enabled)
status = -ENXIO;
else
status = pci_enable_msi(dev);
if (status) {
pr_warn_ratelimited("%s: error enabling MSI for guest %u: err %d\n",
pci_name(dev), pdev->xdev->otherend_id,
status);
op->value = 0;
return XEN_PCI_ERR_op_failed;
}
/* The value the guest needs is actually the IDT vector, not the
* the local domain's IRQ number. */
op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
op->value);
dev_data = pci_get_drvdata(dev);
if (dev_data)
dev_data->ack_intr = 0;
return 0;
}
static
int xen_pcibk_disable_msi(struct xen_pcibk_device *pdev,
struct pci_dev *dev, struct xen_pci_op *op)
{
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: disable MSI\n",
pci_name(dev));
if (dev->msi_enabled) {
struct xen_pcibk_dev_data *dev_data;
pci_disable_msi(dev);
dev_data = pci_get_drvdata(dev);
if (dev_data)
dev_data->ack_intr = 1;
}
op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: MSI: %d\n", pci_name(dev),
op->value);
return 0;
}
static
int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev,
struct pci_dev *dev, struct xen_pci_op *op)
{
struct xen_pcibk_dev_data *dev_data;
int i, result;
struct msix_entry *entries;
u16 cmd;
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: enable MSI-X\n",
pci_name(dev));
if (op->value > SH_INFO_MAX_VEC)
return -EINVAL;
if (dev->msix_enabled)
return -EALREADY;
/*
* PCI_COMMAND_MEMORY must be enabled, otherwise we may not be able
* to access the BARs where the MSI-X entries reside.
* But VF devices are unique in which the PF needs to be checked.
*/
pci_read_config_word(pci_physfn(dev), PCI_COMMAND, &cmd);
if (dev->msi_enabled || !(cmd & PCI_COMMAND_MEMORY))
return -ENXIO;
entries = kmalloc(op->value * sizeof(*entries), GFP_KERNEL);
if (entries == NULL)
return -ENOMEM;
for (i = 0; i < op->value; i++) {
entries[i].entry = op->msix_entries[i].entry;
entries[i].vector = op->msix_entries[i].vector;
}
result = pci_enable_msix_exact(dev, entries, op->value);
if (result == 0) {
for (i = 0; i < op->value; i++) {
op->msix_entries[i].entry = entries[i].entry;
if (entries[i].vector) {
op->msix_entries[i].vector =
xen_pirq_from_irq(entries[i].vector);
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: " \
"MSI-X[%d]: %d\n",
pci_name(dev), i,
op->msix_entries[i].vector);
}
}
} else
pr_warn_ratelimited("%s: error enabling MSI-X for guest %u: err %d!\n",
pci_name(dev), pdev->xdev->otherend_id,
result);
kfree(entries);
op->value = result;
dev_data = pci_get_drvdata(dev);
if (dev_data)
dev_data->ack_intr = 0;
return result > 0 ? 0 : result;
}
static
int xen_pcibk_disable_msix(struct xen_pcibk_device *pdev,
struct pci_dev *dev, struct xen_pci_op *op)
{
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: disable MSI-X\n",
pci_name(dev));
if (dev->msix_enabled) {
struct xen_pcibk_dev_data *dev_data;
pci_disable_msix(dev);
dev_data = pci_get_drvdata(dev);
if (dev_data)
dev_data->ack_intr = 1;
}
/*
* SR-IOV devices (which don't have any legacy IRQ) have
* an undefined IRQ value of zero.
*/
op->value = dev->irq ? xen_pirq_from_irq(dev->irq) : 0;
if (unlikely(verbose_request))
printk(KERN_DEBUG DRV_NAME ": %s: MSI-X: %d\n",
pci_name(dev), op->value);
return 0;
}
#endif
/*
* Now the same evtchn is used for both pcifront conf_read_write request
* as well as pcie aer front end ack. We use a new work_queue to schedule
* xen_pcibk conf_read_write service for avoiding confict with aer_core
* do_recovery job which also use the system default work_queue
*/
void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev)
{
/* Check that frontend is requesting an operation and that we are not
* already processing a request */
if (test_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags)
&& !test_and_set_bit(_PDEVF_op_active, &pdev->flags)) {
schedule_work(&pdev->op_work);
}
/*_XEN_PCIB_active should have been cleared by pcifront. And also make
sure xen_pcibk is waiting for ack by checking _PCIB_op_pending*/
if (!test_bit(_XEN_PCIB_active, (unsigned long *)&pdev->sh_info->flags)
&& test_bit(_PCIB_op_pending, &pdev->flags)) {
wake_up(&xen_pcibk_aer_wait_queue);
}
}
/* Performing the configuration space reads/writes must not be done in atomic
* context because some of the pci_* functions can sleep (mostly due to ACPI
* use of semaphores). This function is intended to be called from a work
* queue in process context taking a struct xen_pcibk_device as a parameter */
void xen_pcibk_do_op(struct work_struct *data)
{
struct xen_pcibk_device *pdev =
container_of(data, struct xen_pcibk_device, op_work);
struct pci_dev *dev;
struct xen_pcibk_dev_data *dev_data = NULL;
struct xen_pci_op *op = &pdev->op;
int test_intx = 0;
#ifdef CONFIG_PCI_MSI
unsigned int nr = 0;
#endif
*op = pdev->sh_info->op;
barrier();
dev = xen_pcibk_get_pci_dev(pdev, op->domain, op->bus, op->devfn);
if (dev == NULL)
op->err = XEN_PCI_ERR_dev_not_found;
else {
dev_data = pci_get_drvdata(dev);
if (dev_data)
test_intx = dev_data->enable_intx;
switch (op->cmd) {
case XEN_PCI_OP_conf_read:
op->err = xen_pcibk_config_read(dev,
op->offset, op->size, &op->value);
break;
case XEN_PCI_OP_conf_write:
op->err = xen_pcibk_config_write(dev,
op->offset, op->size, op->value);
break;
#ifdef CONFIG_PCI_MSI
case XEN_PCI_OP_enable_msi:
op->err = xen_pcibk_enable_msi(pdev, dev, op);
break;
case XEN_PCI_OP_disable_msi:
op->err = xen_pcibk_disable_msi(pdev, dev, op);
break;
case XEN_PCI_OP_enable_msix:
nr = op->value;
op->err = xen_pcibk_enable_msix(pdev, dev, op);
break;
case XEN_PCI_OP_disable_msix:
op->err = xen_pcibk_disable_msix(pdev, dev, op);
break;
#endif
default:
op->err = XEN_PCI_ERR_not_implemented;
break;
}
}
if (!op->err && dev && dev_data) {
/* Transition detected */
if ((dev_data->enable_intx != test_intx))
xen_pcibk_control_isr(dev, 0 /* no reset */);
}
pdev->sh_info->op.err = op->err;
pdev->sh_info->op.value = op->value;
#ifdef CONFIG_PCI_MSI
if (op->cmd == XEN_PCI_OP_enable_msix && op->err == 0) {
unsigned int i;
for (i = 0; i < nr; i++)
pdev->sh_info->op.msix_entries[i].vector =
op->msix_entries[i].vector;
}
#endif
/* Tell the driver domain that we're done. */
wmb();
clear_bit(_XEN_PCIF_active, (unsigned long *)&pdev->sh_info->flags);
notify_remote_via_irq(pdev->evtchn_irq);
/* Mark that we're done. */
smp_mb__before_atomic(); /* /after/ clearing PCIF_active */
clear_bit(_PDEVF_op_active, &pdev->flags);
smp_mb__after_atomic(); /* /before/ final check for work */
/* Check to see if the driver domain tried to start another request in
* between clearing _XEN_PCIF_active and clearing _PDEVF_op_active.
*/
xen_pcibk_test_and_schedule_op(pdev);
}
irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id)
{
struct xen_pcibk_device *pdev = dev_id;
xen_pcibk_test_and_schedule_op(pdev);
return IRQ_HANDLED;
}
static irqreturn_t xen_pcibk_guest_interrupt(int irq, void *dev_id)
{
struct pci_dev *dev = (struct pci_dev *)dev_id;
struct xen_pcibk_dev_data *dev_data = pci_get_drvdata(dev);
if (dev_data->isr_on && dev_data->ack_intr) {
dev_data->handled++;
if ((dev_data->handled % 1000) == 0) {
if (xen_test_irq_shared(irq)) {
pr_info("%s IRQ line is not shared "
"with other domains. Turning ISR off\n",
dev_data->irq_name);
dev_data->ack_intr = 0;
}
}
return IRQ_HANDLED;
}
return IRQ_NONE;
}
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