Commit 56d2731c authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

Merge branch 'pci/hotplug' 

- Ignore pciehp Link Down/Up caused by DPC so device remains bound to
  driver (Lukas Wunner)

- Declare global cpci_debug in header file (Krzysztof Wilczyński)

* pci/hotplug:
  PCI: cpcihp: Declare cpci_debug in header file
  PCI: pciehp: Ignore Link Down/Up caused by DPC
parents 5f2554cc 6d71cc4c

drivers/pci/hotplug/cpci_hotplug.h

+3 −0
Original line number Diff line number Diff line
@@ -75,6 +75,9 @@ int cpci_hp_unregister_bus(struct pci_bus *bus); 
int cpci_hp_start(void);

int cpci_hp_stop(void);



/* Global variables */

extern int cpci_debug;



/*

 * Internal function prototypes, these functions should not be used by

 * board/chassis drivers.

drivers/pci/hotplug/cpci_hotplug_pci.c

+0 −2
Original line number Diff line number Diff line
@@ -19,8 +19,6 @@ 


#define MY_NAME	"cpci_hotplug"



extern int cpci_debug;



#define dbg(format, arg...)					\

	do {							\

		if (cpci_debug)					\

drivers/pci/hotplug/pciehp_hpc.c

+36 −0
Original line number Diff line number Diff line
@@ -563,6 +563,32 @@ void pciehp_power_off_slot(struct controller *ctrl) 
		 PCI_EXP_SLTCTL_PWR_OFF);

}



static void pciehp_ignore_dpc_link_change(struct controller *ctrl,

					  struct pci_dev *pdev, int irq)

{

	/*

	 * Ignore link changes which occurred while waiting for DPC recovery.

	 * Could be several if DPC triggered multiple times consecutively.

	 */

	synchronize_hardirq(irq);

	atomic_and(~PCI_EXP_SLTSTA_DLLSC, &ctrl->pending_events);

	if (pciehp_poll_mode)

		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,

					   PCI_EXP_SLTSTA_DLLSC);

	ctrl_info(ctrl, "Slot(%s): Link Down/Up ignored (recovered by DPC)\n",

		  slot_name(ctrl));



	/*

	 * If the link is unexpectedly down after successful recovery,

	 * the corresponding link change may have been ignored above.

	 * Synthesize it to ensure that it is acted on.

	 */

	down_read(&ctrl->reset_lock);

	if (!pciehp_check_link_active(ctrl))

		pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC);

	up_read(&ctrl->reset_lock);

}



static irqreturn_t pciehp_isr(int irq, void *dev_id)

{

	struct controller *ctrl = (struct controller *)dev_id;
@@ -706,6 +732,16 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id) 
				      PCI_EXP_SLTCTL_ATTN_IND_ON);

	}



	/*

	 * Ignore Link Down/Up events caused by Downstream Port Containment

	 * if recovery from the error succeeded.

	 */

	if ((events & PCI_EXP_SLTSTA_DLLSC) && pci_dpc_recovered(pdev) &&

	    ctrl->state == ON_STATE) {

		events &= ~PCI_EXP_SLTSTA_DLLSC;

		pciehp_ignore_dpc_link_change(ctrl, pdev, irq);

	}



	/*

	 * Disable requests have higher priority than Presence Detect Changed

	 * or Data Link Layer State Changed events.

drivers/pci/pci.h

+4 −0
Original line number Diff line number Diff line
@@ -385,6 +385,8 @@ static inline bool pci_dev_is_disconnected(const struct pci_dev *dev) 


/* pci_dev priv_flags */

#define PCI_DEV_ADDED 0

#define PCI_DPC_RECOVERED 1

#define PCI_DPC_RECOVERING 2



static inline void pci_dev_assign_added(struct pci_dev *dev, bool added)

{
@@ -439,10 +441,12 @@ void pci_restore_dpc_state(struct pci_dev *dev); 
void pci_dpc_init(struct pci_dev *pdev);

void dpc_process_error(struct pci_dev *pdev);

pci_ers_result_t dpc_reset_link(struct pci_dev *pdev);

bool pci_dpc_recovered(struct pci_dev *pdev);

#else

static inline void pci_save_dpc_state(struct pci_dev *dev) {}

static inline void pci_restore_dpc_state(struct pci_dev *dev) {}

static inline void pci_dpc_init(struct pci_dev *pdev) {}

static inline bool pci_dpc_recovered(struct pci_dev *pdev) { return false; }

#endif



#ifdef CONFIG_PCIEPORTBUS

drivers/pci/pcie/dpc.c

+69 −5
Original line number Diff line number Diff line
@@ -71,6 +71,58 @@ void pci_restore_dpc_state(struct pci_dev *dev) 
	pci_write_config_word(dev, dev->dpc_cap + PCI_EXP_DPC_CTL, *cap);

}



static DECLARE_WAIT_QUEUE_HEAD(dpc_completed_waitqueue);



#ifdef CONFIG_HOTPLUG_PCI_PCIE

static bool dpc_completed(struct pci_dev *pdev)

{

	u16 status;



	pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_STATUS, &status);

	if ((status != 0xffff) && (status & PCI_EXP_DPC_STATUS_TRIGGER))

		return false;



	if (test_bit(PCI_DPC_RECOVERING, &pdev->priv_flags))

		return false;



	return true;

}



/**

 * pci_dpc_recovered - whether DPC triggered and has recovered successfully

 * @pdev: PCI device

 *

 * Return true if DPC was triggered for @pdev and has recovered successfully.

 * Wait for recovery if it hasn't completed yet.  Called from the PCIe hotplug

 * driver to recognize and ignore Link Down/Up events caused by DPC.

 */

bool pci_dpc_recovered(struct pci_dev *pdev)

{

	struct pci_host_bridge *host;



	if (!pdev->dpc_cap)

		return false;



	/*

	 * Synchronization between hotplug and DPC is not supported

	 * if DPC is owned by firmware and EDR is not enabled.

	 */

	host = pci_find_host_bridge(pdev->bus);

	if (!host->native_dpc && !IS_ENABLED(CONFIG_PCIE_EDR))

		return false;



	/*

	 * Need a timeout in case DPC never completes due to failure of

	 * dpc_wait_rp_inactive().  The spec doesn't mandate a time limit,

	 * but reports indicate that DPC completes within 4 seconds.

	 */

	wait_event_timeout(dpc_completed_waitqueue, dpc_completed(pdev),

			   msecs_to_jiffies(4000));



	return test_and_clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags);

}

#endif /* CONFIG_HOTPLUG_PCI_PCIE */



static int dpc_wait_rp_inactive(struct pci_dev *pdev)

{

	unsigned long timeout = jiffies + HZ;
@@ -91,8 +143,11 @@ static int dpc_wait_rp_inactive(struct pci_dev *pdev) 


pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)

{

	pci_ers_result_t ret;

	u16 cap;



	set_bit(PCI_DPC_RECOVERING, &pdev->priv_flags);



	/*

	 * DPC disables the Link automatically in hardware, so it has

	 * already been reset by the time we get here.
@@ -106,18 +161,27 @@ pci_ers_result_t dpc_reset_link(struct pci_dev *pdev) 
	if (!pcie_wait_for_link(pdev, false))

		pci_info(pdev, "Data Link Layer Link Active not cleared in 1000 msec\n");



	if (pdev->dpc_rp_extensions && dpc_wait_rp_inactive(pdev))

		return PCI_ERS_RESULT_DISCONNECT;

	if (pdev->dpc_rp_extensions && dpc_wait_rp_inactive(pdev)) {

		clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags);

		ret = PCI_ERS_RESULT_DISCONNECT;

		goto out;

	}



	pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,

			      PCI_EXP_DPC_STATUS_TRIGGER);



	if (!pcie_wait_for_link(pdev, true)) {

		pci_info(pdev, "Data Link Layer Link Active not set in 1000 msec\n");

		return PCI_ERS_RESULT_DISCONNECT;

		clear_bit(PCI_DPC_RECOVERED, &pdev->priv_flags);

		ret = PCI_ERS_RESULT_DISCONNECT;

	} else {

		set_bit(PCI_DPC_RECOVERED, &pdev->priv_flags);

		ret = PCI_ERS_RESULT_RECOVERED;

	}



	return PCI_ERS_RESULT_RECOVERED;

out:

	clear_bit(PCI_DPC_RECOVERING, &pdev->priv_flags);

	wake_up_all(&dpc_completed_waitqueue);

	return ret;

}



static void dpc_process_rp_pio_error(struct pci_dev *pdev)