From ffbdd3f7931fb7cb7e36d00d16303ec433be5145 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Tue, 10 May 2011 10:02:27 -0600 Subject: PCI: Add interfaces to store and load the device saved state For KVM device assignment, we'd like to save off the state of a device prior to passing it to the guest and restore it later. We also want to allow pci_reset_funciton() to be called while the device is owned by the guest. This however overwrites and invalidates the struct pci_dev buffers, so we can't just manually call save and restore. Add generic interfaces for the saved state to be stored and reloaded back into struct pci_dev at a later time. Signed-off-by: Alex Williamson Signed-off-by: Jesse Barnes --- drivers/pci/pci.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) (limited to 'drivers') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index d6e5b8ea919..22c9b27fdd8 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -976,6 +976,104 @@ void pci_restore_state(struct pci_dev *dev) dev->state_saved = false; } +struct pci_saved_state { + u32 config_space[16]; + struct pci_cap_saved_data cap[0]; +}; + +/** + * pci_store_saved_state - Allocate and return an opaque struct containing + * the device saved state. + * @dev: PCI device that we're dealing with + * + * Rerturn NULL if no state or error. + */ +struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev) +{ + struct pci_saved_state *state; + struct pci_cap_saved_state *tmp; + struct pci_cap_saved_data *cap; + struct hlist_node *pos; + size_t size; + + if (!dev->state_saved) + return NULL; + + size = sizeof(*state) + sizeof(struct pci_cap_saved_data); + + hlist_for_each_entry(tmp, pos, &dev->saved_cap_space, next) + size += sizeof(struct pci_cap_saved_data) + tmp->cap.size; + + state = kzalloc(size, GFP_KERNEL); + if (!state) + return NULL; + + memcpy(state->config_space, dev->saved_config_space, + sizeof(state->config_space)); + + cap = state->cap; + hlist_for_each_entry(tmp, pos, &dev->saved_cap_space, next) { + size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size; + memcpy(cap, &tmp->cap, len); + cap = (struct pci_cap_saved_data *)((u8 *)cap + len); + } + /* Empty cap_save terminates list */ + + return state; +} +EXPORT_SYMBOL_GPL(pci_store_saved_state); + +/** + * pci_load_saved_state - Reload the provided save state into struct pci_dev. + * @dev: PCI device that we're dealing with + * @state: Saved state returned from pci_store_saved_state() + */ +int pci_load_saved_state(struct pci_dev *dev, struct pci_saved_state *state) +{ + struct pci_cap_saved_data *cap; + + dev->state_saved = false; + + if (!state) + return 0; + + memcpy(dev->saved_config_space, state->config_space, + sizeof(state->config_space)); + + cap = state->cap; + while (cap->size) { + struct pci_cap_saved_state *tmp; + + tmp = pci_find_saved_cap(dev, cap->cap_nr); + if (!tmp || tmp->cap.size != cap->size) + return -EINVAL; + + memcpy(tmp->cap.data, cap->data, tmp->cap.size); + cap = (struct pci_cap_saved_data *)((u8 *)cap + + sizeof(struct pci_cap_saved_data) + cap->size); + } + + dev->state_saved = true; + return 0; +} +EXPORT_SYMBOL_GPL(pci_load_saved_state); + +/** + * pci_load_and_free_saved_state - Reload the save state pointed to by state, + * and free the memory allocated for it. + * @dev: PCI device that we're dealing with + * @state: Pointer to saved state returned from pci_store_saved_state() + */ +int pci_load_and_free_saved_state(struct pci_dev *dev, + struct pci_saved_state **state) +{ + int ret = pci_load_saved_state(dev, *state); + kfree(*state); + *state = NULL; + return ret; +} +EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state); + static int do_pci_enable_device(struct pci_dev *dev, int bars) { int err; -- cgit v1.2.3