diff options
Diffstat (limited to 'drivers/xen/xen-pciback/conf_space_capability.c')
| -rw-r--r-- | drivers/xen/xen-pciback/conf_space_capability.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/drivers/xen/xen-pciback/conf_space_capability.c b/drivers/xen/xen-pciback/conf_space_capability.c new file mode 100644 index 000000000000..7f83e9083e9d --- /dev/null +++ b/drivers/xen/xen-pciback/conf_space_capability.c @@ -0,0 +1,207 @@ +/* + * PCI Backend - Handles the virtual fields found on the capability lists + * in the configuration space. + * + * Author: Ryan Wilson <hap9@epoch.ncsc.mil> + */ + +#include <linux/kernel.h> +#include <linux/pci.h> +#include "pciback.h" +#include "conf_space.h" + +static LIST_HEAD(capabilities); +struct xen_pcibk_config_capability { + struct list_head cap_list; + + int capability; + + /* If the device has the capability found above, add these fields */ + const struct config_field *fields; +}; + +static const struct config_field caplist_header[] = { + { + .offset = PCI_CAP_LIST_ID, + .size = 2, /* encompass PCI_CAP_LIST_ID & PCI_CAP_LIST_NEXT */ + .u.w.read = xen_pcibk_read_config_word, + .u.w.write = NULL, + }, + {} +}; + +static inline void register_capability(struct xen_pcibk_config_capability *cap) +{ + list_add_tail(&cap->cap_list, &capabilities); +} + +int xen_pcibk_config_capability_add_fields(struct pci_dev *dev) +{ + int err = 0; + struct xen_pcibk_config_capability *cap; + int cap_offset; + + list_for_each_entry(cap, &capabilities, cap_list) { + cap_offset = pci_find_capability(dev, cap->capability); + if (cap_offset) { + dev_dbg(&dev->dev, "Found capability 0x%x at 0x%x\n", + cap->capability, cap_offset); + + err = xen_pcibk_config_add_fields_offset(dev, + caplist_header, + cap_offset); + if (err) + goto out; + err = xen_pcibk_config_add_fields_offset(dev, + cap->fields, + cap_offset); + if (err) + goto out; + } + } + +out: + return err; +} + +static int vpd_address_write(struct pci_dev *dev, int offset, u16 value, + void *data) +{ + /* Disallow writes to the vital product data */ + if (value & PCI_VPD_ADDR_F) + return PCIBIOS_SET_FAILED; + else + return pci_write_config_word(dev, offset, value); +} + +static const struct config_field caplist_vpd[] = { + { + .offset = PCI_VPD_ADDR, + .size = 2, + .u.w.read = xen_pcibk_read_config_word, + .u.w.write = vpd_address_write, + }, + { + .offset = PCI_VPD_DATA, + .size = 4, + .u.dw.read = xen_pcibk_read_config_dword, + .u.dw.write = NULL, + }, + {} +}; + +static int pm_caps_read(struct pci_dev *dev, int offset, u16 *value, + void *data) +{ + int err; + u16 real_value; + + err = pci_read_config_word(dev, offset, &real_value); + if (err) + goto out; + + *value = real_value & ~PCI_PM_CAP_PME_MASK; + +out: + return err; +} + +/* PM_OK_BITS specifies the bits that the driver domain is allowed to change. + * Can't allow driver domain to enable PMEs - they're shared */ +#define PM_OK_BITS (PCI_PM_CTRL_PME_STATUS|PCI_PM_CTRL_DATA_SEL_MASK) + +static int pm_ctrl_write(struct pci_dev *dev, int offset, u16 new_value, + void *data) +{ + int err; + u16 old_value; + pci_power_t new_state, old_state; + + err = pci_read_config_word(dev, offset, &old_value); + if (err) + goto out; + + old_state = (pci_power_t)(old_value & PCI_PM_CTRL_STATE_MASK); + new_state = (pci_power_t)(new_value & PCI_PM_CTRL_STATE_MASK); + + new_value &= PM_OK_BITS; + if ((old_value & PM_OK_BITS) != new_value) { + new_value = (old_value & ~PM_OK_BITS) | new_value; + err = pci_write_config_word(dev, offset, new_value); + if (err) + goto out; + } + + /* Let pci core handle the power management change */ + dev_dbg(&dev->dev, "set power state to %x\n", new_state); + err = pci_set_power_state(dev, new_state); + if (err) { + err = PCIBIOS_SET_FAILED; + goto out; + } + + out: + return err; +} + +/* Ensure PMEs are disabled */ +static void *pm_ctrl_init(struct pci_dev *dev, int offset) +{ + int err; + u16 value; + + err = pci_read_config_word(dev, offset, &value); + if (err) + goto out; + + if (value & PCI_PM_CTRL_PME_ENABLE) { + value &= ~PCI_PM_CTRL_PME_ENABLE; + err = pci_write_config_word(dev, offset, value); + } + +out: + return ERR_PTR(err); +} + +static const struct config_field caplist_pm[] = { + { + .offset = PCI_PM_PMC, + .size = 2, + .u.w.read = pm_caps_read, + }, + { + .offset = PCI_PM_CTRL, + .size = 2, + .init = pm_ctrl_init, + .u.w.read = xen_pcibk_read_config_word, + .u.w.write = pm_ctrl_write, + }, + { + .offset = PCI_PM_PPB_EXTENSIONS, + .size = 1, + .u.b.read = xen_pcibk_read_config_byte, + }, + { + .offset = PCI_PM_DATA_REGISTER, + .size = 1, + .u.b.read = xen_pcibk_read_config_byte, + }, + {} +}; + +static struct xen_pcibk_config_capability xen_pcibk_config_capability_pm = { + .capability = PCI_CAP_ID_PM, + .fields = caplist_pm, +}; +static struct xen_pcibk_config_capability xen_pcibk_config_capability_vpd = { + .capability = PCI_CAP_ID_VPD, + .fields = caplist_vpd, +}; + +int xen_pcibk_config_capability_init(void) +{ + register_capability(&xen_pcibk_config_capability_vpd); + register_capability(&xen_pcibk_config_capability_pm); + + return 0; +} |