diff options
Diffstat (limited to 'drivers/xen/xen-pciback/conf_space.c')
-rw-r--r-- | drivers/xen/xen-pciback/conf_space.c | 438 |
1 files changed, 438 insertions, 0 deletions
diff --git a/drivers/xen/xen-pciback/conf_space.c b/drivers/xen/xen-pciback/conf_space.c new file mode 100644 index 000000000..9c234209d --- /dev/null +++ b/drivers/xen/xen-pciback/conf_space.c @@ -0,0 +1,438 @@ +/* + * 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/module.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 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 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; + + 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 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 req_start, req_end, 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; + + 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 = xen_pcibk_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 || 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(); +} |