powerpc/eeh: Rework eeh_ops->probe()
With the EEH early probe now being pseries specific there's no need for
eeh_ops->probe() to take a pci_dn. Instead, we can make it take a pci_dev
and use the probe function to map a pci_dev to an eeh_dev. This allows
the platform to implement it's own method for finding (or creating) an
eeh_dev for a given pci_dev which also removes a use of pci_dn in
generic EEH code.
This patch also renames eeh_device_add_late() to eeh_device_probe(). This
better reflects what it does does and removes the last vestiges of the
early/late EEH probe split.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-6-oohall@gmail.com
diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
index 8580238..964a542 100644
--- a/arch/powerpc/include/asm/eeh.h
+++ b/arch/powerpc/include/asm/eeh.h
@@ -215,7 +215,7 @@ enum {
struct eeh_ops {
char *name;
int (*init)(void);
- void* (*probe)(struct pci_dn *pdn, void *data);
+ struct eeh_dev *(*probe)(struct pci_dev *pdev);
int (*set_option)(struct eeh_pe *pe, int option);
int (*get_pe_addr)(struct eeh_pe *pe);
int (*get_state)(struct eeh_pe *pe, int *delay);
@@ -301,7 +301,7 @@ int __exit eeh_ops_unregister(const char *name);
int eeh_check_failure(const volatile void __iomem *token);
int eeh_dev_check_failure(struct eeh_dev *edev);
void eeh_addr_cache_init(void);
-void eeh_add_device_late(struct pci_dev *);
+void eeh_probe_device(struct pci_dev *pdev);
void eeh_remove_device(struct pci_dev *);
int eeh_unfreeze_pe(struct eeh_pe *pe);
int eeh_pe_reset_and_recover(struct eeh_pe *pe);
@@ -356,7 +356,7 @@ static inline int eeh_check_failure(const volatile void __iomem *token)
static inline void eeh_addr_cache_init(void) { }
-static inline void eeh_add_device_late(struct pci_dev *dev) { }
+static inline void eeh_probe_device(struct pci_dev *dev) { }
static inline void eeh_remove_device(struct pci_dev *dev) { }
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 55d3ef6..7cdcb41 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c
@@ -1107,35 +1107,43 @@ static int eeh_init(void)
core_initcall_sync(eeh_init);
/**
- * eeh_add_device_late - Perform EEH initialization for the indicated pci device
+ * eeh_probe_device() - Perform EEH initialization for the indicated pci device
* @dev: pci device for which to set up EEH
*
* This routine must be used to complete EEH initialization for PCI
* devices that were added after system boot (e.g. hotplug, dlpar).
*/
-void eeh_add_device_late(struct pci_dev *dev)
+void eeh_probe_device(struct pci_dev *dev)
{
- struct pci_dn *pdn;
struct eeh_dev *edev;
- if (!dev)
- return;
+ pr_debug("EEH: Adding device %s\n", pci_name(dev));
- pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
- edev = pdn_to_eeh_dev(pdn);
- eeh_edev_dbg(edev, "Adding device\n");
- if (edev->pdev == dev) {
- eeh_edev_dbg(edev, "Device already referenced!\n");
+ /*
+ * pci_dev_to_eeh_dev() can only work if eeh_probe_dev() was
+ * already called for this device.
+ */
+ if (WARN_ON_ONCE(pci_dev_to_eeh_dev(dev))) {
+ pci_dbg(dev, "Already bound to an eeh_dev!\n");
+ return;
+ }
+
+ edev = eeh_ops->probe(dev);
+ if (!edev) {
+ pr_debug("EEH: Adding device failed\n");
return;
}
/*
- * The EEH cache might not be removed correctly because of
- * unbalanced kref to the device during unplug time, which
- * relies on pcibios_release_device(). So we have to remove
- * that here explicitly.
+ * FIXME: We rely on pcibios_release_device() to remove the
+ * existing EEH state. The release function is only called if
+ * the pci_dev's refcount drops to zero so if something is
+ * keeping a ref to a device (e.g. a filesystem) we need to
+ * remove the old EEH state.
+ *
+ * FIXME: HEY MA, LOOK AT ME, NO LOCKING!
*/
- if (edev->pdev) {
+ if (edev->pdev && edev->pdev != dev) {
eeh_rmv_from_parent_pe(edev);
eeh_addr_cache_rmv_dev(edev->pdev);
eeh_sysfs_remove_device(edev->pdev);
@@ -1146,17 +1154,11 @@ void eeh_add_device_late(struct pci_dev *dev)
* into error handler afterwards.
*/
edev->mode |= EEH_DEV_NO_HANDLER;
-
- edev->pdev = NULL;
- dev->dev.archdata.edev = NULL;
}
- if (eeh_has_flag(EEH_PROBE_MODE_DEV))
- eeh_ops->probe(pdn, NULL);
-
+ /* bind the pdev and the edev together */
edev->pdev = dev;
dev->dev.archdata.edev = edev;
-
eeh_addr_cache_insert_dev(dev);
eeh_sysfs_add_device(dev);
}
diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index eaa8dfe..79409e0 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
@@ -41,7 +41,7 @@ static int eeh_event_irq = -EINVAL;
void pnv_pcibios_bus_add_device(struct pci_dev *pdev)
{
dev_dbg(&pdev->dev, "EEH: Setting up device\n");
- eeh_add_device_late(pdev);
+ eeh_probe_device(pdev);
}
static int pnv_eeh_init(void)
@@ -340,23 +340,13 @@ static int pnv_eeh_find_ecap(struct pci_dn *pdn, int cap)
/**
* pnv_eeh_probe - Do probe on PCI device
- * @pdn: PCI device node
- * @data: unused
+ * @pdev: pci_dev to probe
*
- * When EEH module is installed during system boot, all PCI devices
- * are checked one by one to see if it supports EEH. The function
- * is introduced for the purpose. By default, EEH has been enabled
- * on all PCI devices. That's to say, we only need do necessary
- * initialization on the corresponding eeh device and create PE
- * accordingly.
- *
- * It's notable that's unsafe to retrieve the EEH device through
- * the corresponding PCI device. During the PCI device hotplug, which
- * was possiblly triggered by EEH core, the binding between EEH device
- * and the PCI device isn't built yet.
+ * Create, or find the existing, eeh_dev for this pci_dev.
*/
-static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
+static struct eeh_dev *pnv_eeh_probe(struct pci_dev *pdev)
{
+ struct pci_dn *pdn = pci_get_pdn(pdev);
struct pci_controller *hose = pdn->phb;
struct pnv_phb *phb = hose->private_data;
struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
@@ -373,6 +363,14 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
if (!edev || edev->pe)
return NULL;
+ /* already configured? */
+ if (edev->pdev) {
+ pr_debug("%s: found existing edev for %04x:%02x:%02x.%01x\n",
+ __func__, hose->global_number, config_addr >> 8,
+ PCI_SLOT(config_addr), PCI_FUNC(config_addr));
+ return edev;
+ }
+
/* Skip for PCI-ISA bridge */
if ((pdn->class_code >> 8) == PCI_CLASS_BRIDGE_ISA)
return NULL;
@@ -464,7 +462,7 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
eeh_edev_dbg(edev, "EEH enabled on device\n");
- return NULL;
+ return edev;
}
/**
diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c
index 1ca7cf0..8453428 100644
--- a/arch/powerpc/platforms/pseries/eeh_pseries.c
+++ b/arch/powerpc/platforms/pseries/eeh_pseries.c
@@ -77,7 +77,7 @@ void pseries_pcibios_bus_add_device(struct pci_dev *pdev)
eeh_add_to_parent_pe(edev); /* Add as VF PE type */
}
#endif
- eeh_add_device_late(pdev);
+ eeh_probe_device(pdev);
}
/*
@@ -335,6 +335,26 @@ void pseries_eeh_init_edev(struct pci_dn *pdn)
eeh_save_bars(edev);
}
+static struct eeh_dev *pseries_eeh_probe(struct pci_dev *pdev)
+{
+ struct eeh_dev *edev;
+ struct pci_dn *pdn;
+
+ pdn = pci_get_pdn_by_devfn(pdev->bus, pdev->devfn);
+ if (!pdn)
+ return NULL;
+
+ /*
+ * If the system supports EEH on this device then the eeh_dev was
+ * configured and inserted into a PE in pseries_eeh_init_edev()
+ */
+ edev = pdn_to_eeh_dev(pdn);
+ if (!edev || !edev->pe)
+ return NULL;
+
+ return edev;
+}
+
/**
* pseries_eeh_init_edev_recursive - Enable EEH for the indicated device
* @pdn: PCI device node
@@ -813,6 +833,7 @@ static int pseries_notify_resume(struct pci_dn *pdn)
static struct eeh_ops pseries_eeh_ops = {
.name = "pseries",
.init = pseries_eeh_init,
+ .probe = pseries_eeh_probe,
.set_option = pseries_eeh_set_option,
.get_pe_addr = pseries_eeh_get_pe_addr,
.get_state = pseries_eeh_get_state,
