Commit 89ee9f76 authored by Keith Busch's avatar Keith Busch Committed by Bjorn Helgaas
Browse files

PCI: Add device disconnected state 



Add a new state to pci_dev to be set when it is unexpectedly disconnected.
The PCI driver tear down functions can observe this new device state so
they may skip operations that will fail.

The pciehp and pcie-dpc drivers are aware when the link is down, so these
set the flag when their handlers detect the device is disconnected.

Tested-by: default avatarKrishna Dhulipala <krishnad@fb.com>
Signed-off-by: default avatarKeith Busch <keith.busch@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarWei Zhang <wzhang@fb.com>
parent d3881e50

drivers/pci/hotplug/pciehp_pci.c

+6 −0
Original line number Diff line number Diff line
@@ -109,6 +109,12 @@ int pciehp_unconfigure_device(struct slot *p_slot) 
				break;

			}

		}

		if (!presence) {

			pci_dev_set_disconnected(dev, NULL);

			if (pci_has_subordinate(dev))

				pci_walk_bus(dev->subordinate,

					     pci_dev_set_disconnected, NULL);

		}

		pci_stop_and_remove_bus_device(dev);

		/*

		 * Ensure that no new Requests will be generated from

drivers/pci/pci.h

+14 −0
Original line number Diff line number Diff line
@@ -274,6 +274,20 @@ struct pci_sriov { 
	resource_size_t barsz[PCI_SRIOV_NUM_BARS];	/* VF BAR size */

};



/* pci_dev priv_flags */

#define PCI_DEV_DISCONNECTED 0



static inline int pci_dev_set_disconnected(struct pci_dev *dev, void *unused)

{

	set_bit(PCI_DEV_DISCONNECTED, &dev->priv_flags);

	return 0;

}



static inline bool pci_dev_is_disconnected(const struct pci_dev *dev)

{

	return test_bit(PCI_DEV_DISCONNECTED, &dev->priv_flags);

}



#ifdef CONFIG_PCI_ATS

void pci_restore_ats_state(struct pci_dev *dev);

#else

drivers/pci/pcie/pcie-dpc.c

+5 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/init.h>

#include <linux/pci.h>

#include <linux/pcieport_if.h>

#include "../pci.h"



struct dpc_dev {

	struct pcie_device	*dev;
@@ -66,6 +67,10 @@ static void interrupt_event_handler(struct work_struct *work) 
	list_for_each_entry_safe_reverse(dev, temp, &parent->devices,

					 bus_list) {

		pci_dev_get(dev);

		pci_dev_set_disconnected(dev, NULL);

		if (pci_has_subordinate(dev))

			pci_walk_bus(dev->subordinate,

				     pci_dev_set_disconnected, NULL);

		pci_stop_and_remove_bus_device(dev);

		pci_dev_put(dev);

	}

include/linux/pci.h

+2 −0
Original line number Diff line number Diff line
@@ -396,6 +396,8 @@ struct pci_dev { 
	phys_addr_t rom; /* Physical address of ROM if it's not from the BAR */

	size_t romlen; /* Length of ROM if it's not from the BAR */

	char *driver_override; /* Driver name to force a match */



	unsigned long priv_flags; /* Private flags for the pci driver */

};



static inline struct pci_dev *pci_physfn(struct pci_dev *dev)

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