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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
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+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)