Commit b56a5a23 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by Greg Kroah-Hartman
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PCI: Restore PCI Express capability registers after PM event 



Restore PCI Express capability registers after PM event.
This includes maxumum MTU for PCI express and other vital data.

Signed-off-by: default avatarMichael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 6d47a5e4

drivers/pci/pci.c

+50 −0
Original line number Diff line number Diff line
@@ -445,6 +445,51 @@ pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state) 


EXPORT_SYMBOL(pci_choose_state);



static int pci_save_pcie_state(struct pci_dev *dev)

{

	int pos, i = 0;

	struct pci_cap_saved_state *save_state;

	u16 *cap;



	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);

	if (pos <= 0)

		return 0;



	save_state = kzalloc(sizeof(*save_state) + sizeof(u16) * 4, GFP_KERNEL);

	if (!save_state) {

		dev_err(&dev->dev, "Out of memory in pci_save_pcie_state\n");

		return -ENOMEM;

	}

	cap = (u16 *)&save_state->data[0];



	pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &cap[i++]);

	pci_read_config_word(dev, pos + PCI_EXP_LNKCTL, &cap[i++]);

	pci_read_config_word(dev, pos + PCI_EXP_SLTCTL, &cap[i++]);

	pci_read_config_word(dev, pos + PCI_EXP_RTCTL, &cap[i++]);

	pci_add_saved_cap(dev, save_state);

	return 0;

}



static void pci_restore_pcie_state(struct pci_dev *dev)

{

	int i = 0, pos;

	struct pci_cap_saved_state *save_state;

	u16 *cap;



	save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP);

	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);

	if (!save_state || pos <= 0)

		return;

	cap = (u16 *)&save_state->data[0];



	pci_write_config_word(dev, pos + PCI_EXP_DEVCTL, cap[i++]);

	pci_write_config_word(dev, pos + PCI_EXP_LNKCTL, cap[i++]);

	pci_write_config_word(dev, pos + PCI_EXP_SLTCTL, cap[i++]);

	pci_write_config_word(dev, pos + PCI_EXP_RTCTL, cap[i++]);

	pci_remove_saved_cap(save_state);

	kfree(save_state);

}



/**

 * pci_save_state - save the PCI configuration space of a device before suspending

 * @dev: - PCI device that we're dealing with
@@ -460,6 +505,8 @@ pci_save_state(struct pci_dev *dev) 
		return i;

	if ((i = pci_save_msix_state(dev)) != 0)

		return i;

	if ((i = pci_save_pcie_state(dev)) != 0)

		return i;

	return 0;

}
@@ -473,6 +520,9 @@ pci_restore_state(struct pci_dev *dev) 
	int i;

	int val;



	/* PCI Express register must be restored first */

	pci_restore_pcie_state(dev);



	/*

	 * The Base Address register should be programmed before the command

	 * register(s)