Commit 6654c936 authored by Russell Currey's avatar Russell Currey Committed by Michael Ellerman
Browse files

powerpc/eeh: Refactor EEH PE reset functions 



eeh_pe_reset and eeh_reset_pe are two different functions in the same
file which do mostly the same thing.  Not only is this confusing, but
potentially causes disrepancies in functionality, notably eeh_reset_pe
as it does not check return values for failure.

Refactor this into the following:

 - eeh_pe_reset(): stays as is, performs a single operation, exported
 - eeh_pe_reset_full(): new, full reset process that calls eeh_pe_reset()
 - eeh_reset_pe(): removed and replaced by eeh_pe_reset_full()
 - eeh_reset_pe_once(): removed

Signed-off-by: default avatarRussell Currey <ruscur@russell.cc>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 1f52f176

arch/powerpc/include/asm/ppc-pci.h

+1 −1
Original line number Diff line number Diff line
@@ -53,7 +53,7 @@ void eeh_addr_cache_rmv_dev(struct pci_dev *dev); 
struct eeh_dev *eeh_addr_cache_get_dev(unsigned long addr);

void eeh_slot_error_detail(struct eeh_pe *pe, int severity);

int eeh_pci_enable(struct eeh_pe *pe, int function);

int eeh_reset_pe(struct eeh_pe *);

int eeh_pe_reset_full(struct eeh_pe *pe);

void eeh_save_bars(struct eeh_dev *edev);

int rtas_write_config(struct pci_dn *, int where, int size, u32 val);

int rtas_read_config(struct pci_dn *, int where, int size, u32 *val);

arch/powerpc/kernel/eeh.c

+35 −43
Original line number Diff line number Diff line
@@ -808,76 +808,67 @@ static void *eeh_set_dev_freset(void *data, void *flag) 
}



/**

 * eeh_reset_pe_once - Assert the pci #RST line for 1/4 second

 * eeh_pe_reset_full - Complete a full reset process on the indicated PE

 * @pe: EEH PE

 *

 * Assert the PCI #RST line for 1/4 second.

 * This function executes a full reset procedure on a PE, including setting

 * the appropriate flags, performing a fundamental or hot reset, and then

 * deactivating the reset status.  It is designed to be used within the EEH

 * subsystem, as opposed to eeh_pe_reset which is exported to drivers and

 * only performs a single operation at a time.

 *

 * This function will attempt to reset a PE three times before failing.

 */

static void eeh_reset_pe_once(struct eeh_pe *pe)

int eeh_pe_reset_full(struct eeh_pe *pe)

{

	int active_flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE);

	int reset_state = (EEH_PE_RESET | EEH_PE_CFG_BLOCKED);

	int type = EEH_RESET_HOT;

	unsigned int freset = 0;

	int i, state, ret;



	/* Determine type of EEH reset required for

	 * Partitionable Endpoint, a hot-reset (1)

	 * or a fundamental reset (3).

	 * A fundamental reset required by any device under

	 * Partitionable Endpoint trumps hot-reset.

	/*

	 * Determine the type of reset to perform - hot or fundamental.

	 * Hot reset is the default operation, unless any device under the

	 * PE requires a fundamental reset.

	 */

	eeh_pe_dev_traverse(pe, eeh_set_dev_freset, &freset);



	if (freset)

		eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL);

	else

		eeh_ops->reset(pe, EEH_RESET_HOT);



	eeh_ops->reset(pe, EEH_RESET_DEACTIVATE);

}



/**

 * eeh_reset_pe - Reset the indicated PE

 * @pe: EEH PE

 *

 * This routine should be called to reset indicated device, including

 * PE. A PE might include multiple PCI devices and sometimes PCI bridges

 * might be involved as well.

 */

int eeh_reset_pe(struct eeh_pe *pe)

{

	int flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE);

	int i, state, ret;

		type = EEH_RESET_FUNDAMENTAL;



	/* Mark as reset and block config space */

	eeh_pe_state_mark(pe, EEH_PE_RESET | EEH_PE_CFG_BLOCKED);

	/* Mark the PE as in reset state and block config space accesses */

	eeh_pe_state_mark(pe, reset_state);



	/* Take three shots at resetting the bus */

	/* Make three attempts at resetting the bus */

	for (i = 0; i < 3; i++) {

		eeh_reset_pe_once(pe);

		ret = eeh_pe_reset(pe, type);

		if (ret)

			break;



		/*

		 * EEH_PE_ISOLATED is expected to be removed after

		 * BAR restore.

		 */

		ret = eeh_pe_reset(pe, EEH_RESET_DEACTIVATE);

		if (ret)

			break;



		/* Wait until the PE is in a functioning state */

		state = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC);

		if ((state & flags) == flags) {

			ret = 0;

			goto out;

		}

		if ((state & active_flags) == active_flags)

			break;



		if (state < 0) {

			pr_warn("%s: Unrecoverable slot failure on PHB#%x-PE#%x",

				__func__, pe->phb->global_number, pe->addr);

			ret = -ENOTRECOVERABLE;

			goto out;

			break;

		}



		/* We might run out of credits */

		/* Set error in case this is our last attempt */

		ret = -EIO;

		pr_warn("%s: Failure %d resetting PHB#%x-PE#%x\n (%d)\n",

			__func__, state, pe->phb->global_number, pe->addr, (i + 1));

	}



out:

	eeh_pe_state_clear(pe, EEH_PE_RESET | EEH_PE_CFG_BLOCKED);

	eeh_pe_state_clear(pe, reset_state);

	return ret;

}
@@ -1601,6 +1592,7 @@ static int eeh_pe_reenable_devices(struct eeh_pe *pe) 
	return eeh_unfreeze_pe(pe, true);

}





/**

 * eeh_pe_reset - Issue PE reset according to specified type

 * @pe: EEH PE

arch/powerpc/kernel/eeh_driver.c

+2 −2
Original line number Diff line number Diff line
@@ -588,7 +588,7 @@ int eeh_pe_reset_and_recover(struct eeh_pe *pe) 
	eeh_pe_dev_traverse(pe, eeh_dev_save_state, NULL);



	/* Issue reset */

	ret = eeh_reset_pe(pe);

	ret = eeh_pe_reset_full(pe);

	if (ret) {

		eeh_pe_state_clear(pe, EEH_PE_RECOVERING);

		return ret;
@@ -659,7 +659,7 @@ static int eeh_reset_device(struct eeh_pe *pe, struct pci_bus *bus, 
	 * config accesses. So we prefer to block them. However, controlled

	 * PCI config accesses initiated from EEH itself are allowed.

	 */

	rc = eeh_reset_pe(pe);

	rc = eeh_pe_reset_full(pe);

	if (rc)

		return rc;

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