432 lines
11 KiB
C
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();
|
|
}
|