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powerpc/eeh: Move PE tree setup into the platform

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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: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200725081231.39076-14-oohall@gmail.com
This commit is contained in:
Oliver O'Halloran
2020-07-25 18:12:31 +10:00
committed by Michael Ellerman
parent 31595ae5ae
commit a131bfc69b
4 changed files with 103 additions and 64 deletions
Download Patch File Download Diff File Expand all files Collapse all files

71
arch/powerpc/kernel/eeh_pe.c
View File

@@ -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 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.
* 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.
*
* 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;
}