[PATCH v2 14/14] powerpc/eeh: Move PE tree setup into the platform
Oliver O'Halloran
oohall at gmail.com
Wed Jul 22 14:26:28 AEST 2020
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 at gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
v2: Reworked pseries PE setup slightly. NOT DONE YET. mostly done needs test
---
arch/powerpc/include/asm/eeh.h | 2 +-
arch/powerpc/kernel/eeh_pe.c | 70 ++++++--------------
arch/powerpc/platforms/powernv/eeh-powernv.c | 27 +++++++-
arch/powerpc/platforms/pseries/eeh_pseries.c | 66 +++++++++++++++---
4 files changed, 102 insertions(+), 63 deletions(-)
diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
index df9462230e75..187c23324d96 100644
--- a/arch/powerpc/include/asm/eeh.h
+++ b/arch/powerpc/include/asm/eeh.h
@@ -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,
diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c
index 898205829a8f..ea2f8b362d18 100644
--- a/arch/powerpc/kernel/eeh_pe.c
+++ b/arch/powerpc/kernel/eeh_pe.c
@@ -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;
@@ -399,7 +366,7 @@ int eeh_pe_tree_insert(struct eeh_dev *edev)
}
eeh_edev_dbg(edev,
- "Added to device PE (parent: PE#%x)\n",
+ "Added to existing PE (parent: PE#%x)\n",
pe->parent->addr);
} else {
/* Mark the PE as type of PCI bus */
@@ -431,10 +398,9 @@ 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 +408,19 @@ 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;
}
diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index 8c9fca773692..9af8c3b98853 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
@@ -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;
diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c
index 88639b65daa3..8169f3e996fc 100644
--- a/arch/powerpc/platforms/pseries/eeh_pseries.c
+++ b/arch/powerpc/platforms/pseries/eeh_pseries.c
@@ -68,11 +68,16 @@ 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);
@@ -218,6 +223,43 @@ 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
*
@@ -301,6 +343,8 @@ 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;
@@ -313,16 +357,18 @@ 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);
--
2.26.2
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