Commit a131bfc6 authored by Oliver O'Halloran's avatar Oliver O'Halloran Committed by Michael Ellerman
Browse files

powerpc/eeh: Move PE tree setup into the platform 



The EEH core has a concept of a "PE tree" to support PowerNV. The PE tree
follows the PCI bus structures because a reset asserted on an upstream
bridge will be propagated to the downstream bridges. On pseries there's a
1-1 correspondence between what the guest sees are a PHB and a PE so the
"tree" is really just a single node.

Current the EEH core is reponsible for setting up this PE tree which it
does by traversing the pci_dn tree. The structure of the pci_dn tree
matches the bus tree on PowerNV which leads to the PE tree being "correct"
this setup method doesn't make a whole lot of sense and it's actively
confusing for the pseries case where it doesn't really do anything.

We want to remove the dependence on pci_dn anyway so this patch move
choosing where to insert a new PE into the platform code rather than
being part of the generic EEH code. For PowerNV this simplifies the
tree building logic and removes the use of pci_dn. For pseries we
keep the existing logic. I'm not really convinced it does anything
due to the 1-1 PE-to-PHB correspondence so every device under that
PHB should be in the same PE, but I'd rather not remove it entirely
until we've had a chance to look at it more deeply.

Signed-off-by: default avatarOliver O'Halloran <oohall@gmail.com>
Reviewed-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200725081231.39076-14-oohall@gmail.com
parent 31595ae5

arch/powerpc/include/asm/eeh.h

+1 −1
Original line number Diff line number Diff line
@@ -283,7 +283,7 @@ struct eeh_pe *eeh_phb_pe_get(struct pci_controller *phb); 
struct eeh_pe *eeh_pe_next(struct eeh_pe *pe, struct eeh_pe *root);

struct eeh_pe *eeh_pe_get(struct pci_controller *phb,

			  int pe_no, int config_addr);

int eeh_pe_tree_insert(struct eeh_dev *edev);

int eeh_pe_tree_insert(struct eeh_dev *edev, struct eeh_pe *new_pe_parent);

int eeh_pe_tree_remove(struct eeh_dev *edev);

void eeh_pe_update_time_stamp(struct eeh_pe *pe);

void *eeh_pe_traverse(struct eeh_pe *root,

arch/powerpc/kernel/eeh_pe.c

+19 −52
Original line number Diff line number Diff line
@@ -318,53 +318,20 @@ struct eeh_pe *eeh_pe_get(struct pci_controller *phb, 
	return pe;

}



/**

 * eeh_pe_get_parent - Retrieve the parent PE

 * @edev: EEH device

 *

 * The whole PEs existing in the system are organized as hierarchy

 * tree. The function is used to retrieve the parent PE according

 * to the parent EEH device.

 */

static struct eeh_pe *eeh_pe_get_parent(struct eeh_dev *edev)

{

	struct eeh_dev *parent;

	struct pci_dn *pdn = eeh_dev_to_pdn(edev);



	/*

	 * It might have the case for the indirect parent

	 * EEH device already having associated PE, but

	 * the direct parent EEH device doesn't have yet.

	 */

	if (edev->physfn)

		pdn = pci_get_pdn(edev->physfn);

	else

		pdn = pdn ? pdn->parent : NULL;

	while (pdn) {

		/* We're poking out of PCI territory */

		parent = pdn_to_eeh_dev(pdn);

		if (!parent)

			return NULL;



		if (parent->pe)

			return parent->pe;



		pdn = pdn->parent;

	}



	return NULL;

}



/**

 * eeh_pe_tree_insert - Add EEH device to parent PE

 * @edev: EEH device

 * @new_pe_parent: PE to create additional PEs under

 *

 * Add EEH device to the PE in edev->pe_config_addr. If a PE already

 * exists with that address then @edev is added to that PE. Otherwise

 * a new PE is created and inserted into the PE tree as a child of

 * @new_pe_parent.

 *

 * Add EEH device to the parent PE. If the parent PE already

 * exists, the PE type will be changed to EEH_PE_BUS. Otherwise,

 * we have to create new PE to hold the EEH device and the new

 * PE will be linked to its parent PE as well.

 * If @new_pe_parent is NULL then the new PE will be inserted under

 * directly under the the PHB.

 */

int eeh_pe_tree_insert(struct eeh_dev *edev)

int eeh_pe_tree_insert(struct eeh_dev *edev, struct eeh_pe *new_pe_parent)

{

	struct pci_controller *hose = edev->controller;

	struct eeh_pe *pe, *parent;
@@ -398,8 +365,7 @@ int eeh_pe_tree_insert(struct eeh_dev *edev) 
				parent = parent->parent;

			}



			eeh_edev_dbg(edev,

				     "Added to device PE (parent: PE#%x)\n",

			eeh_edev_dbg(edev, "Added to existing PE (parent: PE#%x)\n",

				     pe->parent->addr);

		} else {

			/* Mark the PE as type of PCI bus */
@@ -431,10 +397,9 @@ int eeh_pe_tree_insert(struct eeh_dev *edev) 
	 * to PHB directly. Otherwise, we have to associate the

	 * PE with its parent.

	 */

	parent = eeh_pe_get_parent(edev);

	if (!parent) {

		parent = eeh_phb_pe_get(hose);

		if (!parent) {

	if (!new_pe_parent) {

		new_pe_parent = eeh_phb_pe_get(hose);

		if (!new_pe_parent) {

			pr_err("%s: No PHB PE is found (PHB Domain=%d)\n",

				__func__, hose->global_number);

			edev->pe = NULL;
@@ -442,17 +407,19 @@ int eeh_pe_tree_insert(struct eeh_dev *edev) 
			return -EEXIST;

		}

	}

	pe->parent = parent;



	/* link new PE into the tree */

	pe->parent = new_pe_parent;

	list_add_tail(&pe->child, &new_pe_parent->child_list);



	/*

	 * Put the newly created PE into the child list and

	 * link the EEH device accordingly.

	 */

	list_add_tail(&pe->child, &parent->child_list);

	list_add_tail(&edev->entry, &pe->edevs);

	edev->pe = pe;

	eeh_edev_dbg(edev, "Added to device PE (parent: PE#%x)\n",

		     pe->parent->addr);

	eeh_edev_dbg(edev, "Added to new (parent: PE#%x)\n",

		     new_pe_parent->addr);



	return 0;

}

arch/powerpc/platforms/powernv/eeh-powernv.c

+26 −1
Original line number Diff line number Diff line
@@ -338,6 +338,28 @@ static int pnv_eeh_find_ecap(struct pci_dn *pdn, int cap) 
	return 0;

}



static struct eeh_pe *pnv_eeh_get_upstream_pe(struct pci_dev *pdev)

{

	struct pci_controller *hose = pdev->bus->sysdata;

	struct pnv_phb *phb = hose->private_data;

	struct pci_dev *parent = pdev->bus->self;



#ifdef CONFIG_PCI_IOV

	/* for VFs we use the PF's PE as the upstream PE */

	if (pdev->is_virtfn)

		parent = pdev->physfn;

#endif



	/* otherwise use the PE of our parent bridge */

	if (parent) {

		struct pnv_ioda_pe *ioda_pe = pnv_ioda_get_pe(parent);



		return eeh_pe_get(phb->hose, ioda_pe->pe_number, 0);

	}



	return NULL;

}



/**

 * pnv_eeh_probe - Do probe on PCI device

 * @pdev: pci_dev to probe
@@ -350,6 +372,7 @@ static struct eeh_dev *pnv_eeh_probe(struct pci_dev *pdev) 
	struct pci_controller *hose = pdn->phb;

	struct pnv_phb *phb = hose->private_data;

	struct eeh_dev *edev = pdn_to_eeh_dev(pdn);

	struct eeh_pe *upstream_pe;

	uint32_t pcie_flags;

	int ret;

	int config_addr = (pdn->busno << 8) | (pdn->devfn);
@@ -398,8 +421,10 @@ static struct eeh_dev *pnv_eeh_probe(struct pci_dev *pdev) 


	edev->pe_config_addr = phb->ioda.pe_rmap[config_addr];



	upstream_pe = pnv_eeh_get_upstream_pe(pdev);



	/* Create PE */

	ret = eeh_pe_tree_insert(edev);

	ret = eeh_pe_tree_insert(edev, upstream_pe);

	if (ret) {

		eeh_edev_warn(edev, "Failed to add device to PE (code %d)\n", ret);

		return NULL;

arch/powerpc/platforms/pseries/eeh_pseries.c

+57 −10
Original line number Diff line number Diff line
@@ -69,11 +69,16 @@ void pseries_pcibios_bus_add_device(struct pci_dev *pdev) 
	pseries_eeh_init_edev(pdn);

#ifdef CONFIG_PCI_IOV

	if (pdev->is_virtfn) {

		/*

		 * FIXME: This really should be handled by choosing the right

		 *        parent PE in in pseries_eeh_init_edev().

		 */

		struct eeh_pe *physfn_pe = pci_dev_to_eeh_dev(pdev->physfn)->pe;

		struct eeh_dev *edev = pdn_to_eeh_dev(pdn);



		edev->pe_config_addr =  (pdn->busno << 16) | (pdn->devfn << 8);

		eeh_pe_tree_remove(edev); /* Remove as it is adding to bus pe */

		eeh_pe_tree_insert(edev);   /* Add as VF PE type */

		eeh_pe_tree_insert(edev, physfn_pe);   /* Add as VF PE type */

	}

#endif

	eeh_probe_device(pdev);
@@ -385,6 +390,43 @@ static int pseries_eeh_find_ecap(struct pci_dn *pdn, int cap) 
	return 0;

}



/**

 * pseries_eeh_pe_get_parent - Retrieve the parent PE

 * @edev: EEH device

 *

 * The whole PEs existing in the system are organized as hierarchy

 * tree. The function is used to retrieve the parent PE according

 * to the parent EEH device.

 */

static struct eeh_pe *pseries_eeh_pe_get_parent(struct eeh_dev *edev)

{

	struct eeh_dev *parent;

	struct pci_dn *pdn = eeh_dev_to_pdn(edev);



	/*

	 * It might have the case for the indirect parent

	 * EEH device already having associated PE, but

	 * the direct parent EEH device doesn't have yet.

	 */

	if (edev->physfn)

		pdn = pci_get_pdn(edev->physfn);

	else

		pdn = pdn ? pdn->parent : NULL;

	while (pdn) {

		/* We're poking out of PCI territory */

		parent = pdn_to_eeh_dev(pdn);

		if (!parent)

			return NULL;



		if (parent->pe)

			return parent->pe;



		pdn = pdn->parent;

	}



	return NULL;

}



/**

 * pseries_eeh_init_edev - initialise the eeh_dev and eeh_pe for a pci_dn

 *
@@ -468,6 +510,8 @@ void pseries_eeh_init_edev(struct pci_dn *pdn) 
	if (ret) {

		eeh_edev_dbg(edev, "EEH failed to enable on device (code %d)\n", ret);

	} else {

		struct eeh_pe *parent;



		/* Retrieve PE address */

		edev->pe_config_addr = pseries_eeh_get_pe_addr(pdn);

		pe.addr = edev->pe_config_addr;
@@ -480,16 +524,19 @@ void pseries_eeh_init_edev(struct pci_dn *pdn) 
		if (ret > 0 && ret != EEH_STATE_NOT_SUPPORT)

			enable = 1;



		if (enable) {

		/*

		 * This device doesn't support EEH, but it may have an

		 * EEH parent. In this case any error on the device will

		 * freeze the PE of it's upstream bridge, so added it to

		 * the upstream PE.

		 */

		parent = pseries_eeh_pe_get_parent(edev);

		if (parent && !enable)

			edev->pe_config_addr = parent->addr;



		if (enable || parent) {

			eeh_add_flag(EEH_ENABLED);

			eeh_pe_tree_insert(edev);

		} else if (pdn->parent && pdn_to_eeh_dev(pdn->parent) &&

			   (pdn_to_eeh_dev(pdn->parent))->pe) {

			/* This device doesn't support EEH, but it may have an

			 * EEH parent, in which case we mark it as supported.

			 */

			edev->pe_config_addr = pdn_to_eeh_dev(pdn->parent)->pe_config_addr;

			eeh_pe_tree_insert(edev);

			eeh_pe_tree_insert(edev, parent);

		}

		eeh_edev_dbg(edev, "EEH is %s on device (code %d)\n",

			     (enable ? "enabled" : "unsupported"), ret);

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