| /* |
| * 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/pci.h> |
| #include "pciback.h" |
| #include "conf_space.h" |
| #include "conf_space_quirks.h" |
| |
| static int permissive; |
| module_param(permissive, bool, 0644); |
| |
| #define DEFINE_PCI_CONFIG(op, size, type) \ |
| int pciback_##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 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 pciback_config_read(struct pci_dev *dev, int offset, int size, |
| u32 *ret_val) |
| { |
| int err = 0; |
| struct pciback_dev_data *dev_data = pci_get_drvdata(dev); |
| const struct config_field_entry *cfg_entry; |
| const struct config_field *field; |
| int req_start, req_end, 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 "pciback: %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; |
| |
| req_start = offset; |
| req_end = offset + size; |
| field_start = OFFSET(cfg_entry); |
| field_end = OFFSET(cfg_entry) + field->size; |
| |
| if ((req_start >= field_start && req_start < field_end) |
| || (req_end > field_start && req_end <= field_end)) { |
| 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 - req_start); |
| } |
| } |
| |
| out: |
| if (unlikely(verbose_request)) |
| printk(KERN_DEBUG "pciback: %s: read %d bytes at 0x%x = %x\n", |
| pci_name(dev), size, offset, value); |
| |
| *ret_val = value; |
| return pcibios_err_to_errno(err); |
| } |
| |
| int pciback_config_write(struct pci_dev *dev, int offset, int size, u32 value) |
| { |
| int err = 0, handled = 0; |
| struct pciback_dev_data *dev_data = pci_get_drvdata(dev); |
| const struct config_field_entry *cfg_entry; |
| const struct config_field *field; |
| u32 tmp_val; |
| int req_start, req_end, field_start, field_end; |
| |
| if (unlikely(verbose_request)) |
| printk(KERN_DEBUG |
| "pciback: %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; |
| |
| req_start = offset; |
| req_end = offset + size; |
| field_start = OFFSET(cfg_entry); |
| field_end = OFFSET(cfg_entry) + field->size; |
| |
| if ((req_start >= field_start && req_start < field_end) |
| || (req_end > field_start && req_end <= field_end)) { |
| tmp_val = 0; |
| |
| err = pciback_config_read(dev, field_start, |
| field->size, &tmp_val); |
| if (err) |
| break; |
| |
| tmp_val = merge_value(tmp_val, value, get_mask(size), |
| req_start - 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 || 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 pcibios_err_to_errno(err); |
| } |
| |
| void pciback_config_free_dyn_fields(struct pci_dev *dev) |
| { |
| struct pciback_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 pciback_config_reset_dev(struct pci_dev *dev) |
| { |
| struct pciback_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 pciback_config_free_dev(struct pci_dev *dev) |
| { |
| struct pciback_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 pciback_config_add_field_offset(struct pci_dev *dev, |
| const struct config_field *field, |
| unsigned int base_offset) |
| { |
| int err = 0; |
| struct pciback_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 = pciback_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 pciback_config_init_dev(struct pci_dev *dev) |
| { |
| int err = 0; |
| struct pciback_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 = pciback_config_header_add_fields(dev); |
| if (err) |
| goto out; |
| |
| err = pciback_config_capability_add_fields(dev); |
| if (err) |
| goto out; |
| |
| err = pciback_config_quirks_init(dev); |
| |
| out: |
| return err; |
| } |
| |
| int pciback_config_init(void) |
| { |
| return pciback_config_capability_init(); |
| } |