[PATCH v2 0/6]

Hi all,

Here is v2, addressing feedback from v1.

Original cover letter follows, slightly updated for v2:

This patch set adds support for EEH recovery of hot plugged devices on pSeries
machines. Specifically, devices discovered by PCI rescanning using
/sys/bus/pci/rescan, which includes devices hotplugged by QEMU's device_add
command. (Upstream Linux pSeries guests running under QEMU/KVM don't currently
use slot power control for hotplugging.)

As a side effect this also provides EEH support for devices removed by
/sys/bus/pci/devices/*/remove and re-discovered by writing to /sys/bus/pci/rescan,
on all platforms.

The approach I've taken is to use the fact that the existing
pcibios_bus_add_device() platform hooks (which are used to set up EEH on
Virtual Function devices (VFs)) are actually called for all devices, so I've
widened their scope and made other adjustments necessary to allow them to work
for hotplugged and boot-time devices as well.

Because some of the changes are in generic PowerPC code, it's
possible that I've disturbed something for another PowerPC platform. I've tried
to minimize this by leaving that code alone as much as possible and so there
are a few cases where eeh_add_device_{early,late}() or eeh_add_sysfs_files() is
called more than once. I think these can be looked at later, as duplicate calls
are not harmful.

The first patch is a rework of the pcibios_init reordering patch I posted
earlier, which I've included here because it's necessary for this set.

I have done some testing for PowerNV on Power9 using a modified pnv_php module
and some testing on pSeries with slot power control using a modified rpaphp
module, and the EEH-related parts seem to work.

Cheers,
Sam.

Patch set changelog follows:

Patch set v2: 
Patch 1/6: powerpc/64: Adjust order in pcibios_init()
Patch 2/6: powerpc/eeh: Clear stale EEH_DEV_NO_HANDLER flag
* Also clear EEH_DEV_NO_HANDLER in eeh_handle_special_event().
Patch 3/6 (was 4/8): powerpc/eeh: Improve debug messages around device addition
Patch 4/6 (was 6/8): powerpc/eeh: Initialize EEH address cache earlier
Patch 5/6 (was 3/8 and 7/8): powerpc/eeh: EEH for pSeries hot plug
- Dropped changes to the PowerNV PHB EEH flag, instead refactor just enough to
  use the existing flag from multiple places.
- Merge the little remaining work from the above change into the patch where
  it's used.
Patch 6/6 (was 5/8 and 8/8): powerpc/eeh: Refactor around eeh_probe_devices()
- As it's so small, merged the enablement message patch into this one (where it's used).
- Reworked enablement messages.

Patch set v1:
Patch 1/8: powerpc/64: Adjust order in pcibios_init()
Patch 2/8: powerpc/eeh: Clear stale EEH_DEV_NO_HANDLER flag
Patch 3/8: powerpc/eeh: Convert PNV_PHB_FLAG_EEH to global flag
Patch 4/8: powerpc/eeh: Improve debug messages around device addition
Patch 5/8: powerpc/eeh: Add eeh_show_enabled()
Patch 6/8: powerpc/eeh: Initialize EEH address cache earlier
Patch 7/8: powerpc/eeh: EEH for pSeries hot plug
Patch 8/8: powerpc/eeh: Remove eeh_probe_devices() and eeh_addr_cache_build()

Sam Bobroff (6):
  powerpc/64: Adjust order in pcibios_init()
  powerpc/eeh: Clear stale EEH_DEV_NO_HANDLER flag
  powerpc/eeh: Improve debug messages around device addition
  powerpc/eeh: Initialize EEH address cache earlier
  powerpc/eeh: EEH for pSeries hot plug
  powerpc/eeh: Refactor around eeh_probe_devices()

 arch/powerpc/include/asm/eeh.h               |  8 +--
 arch/powerpc/kernel/eeh.c                    | 33 ++++-----
 arch/powerpc/kernel/eeh_cache.c              | 29 +-------
 arch/powerpc/kernel/eeh_driver.c             | 11 ++-
 arch/powerpc/kernel/of_platform.c            |  3 +-
 arch/powerpc/kernel/pci-common.c             |  4 --
 arch/powerpc/kernel/pci_32.c                 |  4 ++
 arch/powerpc/kernel/pci_64.c                 | 12 +++-
 arch/powerpc/platforms/powernv/eeh-powernv.c | 57 ++++++++++-----
 arch/powerpc/platforms/pseries/eeh_pseries.c | 75 +++++++++++---------
 arch/powerpc/platforms/pseries/pci.c         |  3 +-
 11 files changed, 127 insertions(+), 112 deletions(-)

-- 
2.19.0.2.gcad72f5712

The pcibios_init() function for 64 bit PowerPC currently calls
pci_bus_add_devices() before pcibios_resource_survey(), which seems
incorrect because it adds devices and attempts to bind their drivers
before allocating their resources (although no problems seem to be
apparent).

So move the call to pci_bus_add_devices() to after
pcibios_resource_survey(), while extracting call to the
pcibios_fixup() hook so that it remains in the same location.

This will also allow the ppc_md.pcibios_bus_add_device() hooks to
perform actions that depend on PCI resources, both during rescanning
(where this is already the case) and at boot time, to support future
work.

Signed-off-by: Sam Bobroff <redacted>
Reviewed-by: Alexey Kardashevskiy <redacted>
---
 arch/powerpc/kernel/pci-common.c |  4 ----
 arch/powerpc/kernel/pci_32.c     |  4 ++++
 arch/powerpc/kernel/pci_64.c     | 12 +++++++++---
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index ff4b7539cbdf..3146eb73e3b3 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c

@@ -1383,10 +1383,6 @@ void __init pcibios_resource_survey(void)
 		pr_debug("PCI: Assigning unassigned resources...\n");
 		pci_assign_unassigned_resources();
 	}
-
-	/* Call machine dependent fixup */
-	if (ppc_md.pcibios_fixup)
-		ppc_md.pcibios_fixup();
 }
 
 /* This is used by the PCI hotplug driver to allocate resource

diff --git a/arch/powerpc/kernel/pci_32.c b/arch/powerpc/kernel/pci_32.c
index 0417fda13636..7078122e9cea 100644
--- a/arch/powerpc/kernel/pci_32.c
+++ b/arch/powerpc/kernel/pci_32.c

@@ -262,6 +262,10 @@ static int __init pcibios_init(void)
 	/* Call common code to handle resource allocation */
 	pcibios_resource_survey();
 
+	/* Call machine dependent fixup */
+	if (ppc_md.pcibios_fixup)
+		ppc_md.pcibios_fixup();
+
 	/* Call machine dependent post-init code */
 	if (ppc_md.pcibios_after_init)
 		ppc_md.pcibios_after_init();

diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
index 9d8c10d55407..6f16f30031d7 100644
--- a/arch/powerpc/kernel/pci_64.c
+++ b/arch/powerpc/kernel/pci_64.c

@@ -58,14 +58,20 @@ static int __init pcibios_init(void)
 	pci_add_flags(PCI_ENABLE_PROC_DOMAINS | PCI_COMPAT_DOMAIN_0);
 
 	/* Scan all of the recorded PCI controllers.  */
-	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
+	list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
 		pcibios_scan_phb(hose);
-		pci_bus_add_devices(hose->bus);
-	}
 
 	/* Call common code to handle resource allocation */
 	pcibios_resource_survey();
 
+	/* Add devices. */
+	list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
+		pci_bus_add_devices(hose->bus);
+
+	/* Call machine dependent fixup */
+	if (ppc_md.pcibios_fixup)
+		ppc_md.pcibios_fixup();
+
 	printk(KERN_DEBUG "PCI: Probing PCI hardware done\n");
 
 	return 0;

-- 
2.19.0.2.gcad72f5712

The EEH address cache is currently initialized and populated by a
single function: eeh_addr_cache_build().  While the initial population
of the cache can only be done once resources are allocated,
initialization (just setting up a spinlock) could be done much
earlier.

So move the initialization step into a separate function and call it
from a core_initcall (rather than a subsys initcall).

This will allow future work to make use of the cache during boot time
PCI scanning.

Signed-off-by: Sam Bobroff <redacted>
Reviewed-by: Alexey Kardashevskiy <redacted>
---
 arch/powerpc/include/asm/eeh.h  |  3 +++
 arch/powerpc/kernel/eeh.c       |  2 ++
 arch/powerpc/kernel/eeh_cache.c | 13 +++++++++++--
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
index 3613a56281f2..12baf1df134c 100644
--- a/arch/powerpc/include/asm/eeh.h
+++ b/arch/powerpc/include/asm/eeh.h

@@ -288,6 +288,7 @@ int __init eeh_ops_register(struct eeh_ops *ops);
 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_addr_cache_build(void);
 void eeh_add_device_early(struct pci_dn *);
 void eeh_add_device_tree_early(struct pci_dn *);

@@ -348,6 +349,8 @@ static inline int eeh_check_failure(const volatile void __iomem *token)
 
 #define eeh_dev_check_failure(x) (0)
 
+static inline void eeh_addr_cache_init(void) { }
+
 static inline void eeh_addr_cache_build(void) { }
 
 static inline void eeh_add_device_early(struct pci_dn *pdn) { }

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index b14d89547895..4160514d997c 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c

@@ -1213,6 +1213,8 @@ static int eeh_init(void)
 	list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
 		eeh_dev_phb_init_dynamic(hose);
 
+	eeh_addr_cache_init();
+
 	/* Initialize EEH event */
 	return eeh_event_init();
 }

diff --git a/arch/powerpc/kernel/eeh_cache.c b/arch/powerpc/kernel/eeh_cache.c
index 9c68f0837385..f93dd5cf6a39 100644
--- a/arch/powerpc/kernel/eeh_cache.c
+++ b/arch/powerpc/kernel/eeh_cache.c

@@ -267,6 +267,17 @@ void eeh_addr_cache_rmv_dev(struct pci_dev *dev)
 	spin_unlock_irqrestore(&pci_io_addr_cache_root.piar_lock, flags);
 }
 
+/**
+ * eeh_addr_cache_init - Initialize a cache of I/O addresses
+ *
+ * Initialize a cache of pci i/o addresses.  This cache will be used to
+ * find the pci device that corresponds to a given address.
+ */
+void eeh_addr_cache_init(void)
+{
+	spin_lock_init(&pci_io_addr_cache_root.piar_lock);
+}
+
 /**
  * eeh_addr_cache_build - Build a cache of I/O addresses
  *

@@ -282,8 +293,6 @@ void eeh_addr_cache_build(void)
 	struct eeh_dev *edev;
 	struct pci_dev *dev = NULL;
 
-	spin_lock_init(&pci_io_addr_cache_root.piar_lock);
-
 	for_each_pci_dev(dev) {
 		pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
 		if (!pdn)

-- 
2.19.0.2.gcad72f5712

The EEH_DEV_NO_HANDLER flag is used by the EEH system to prevent the
use of driver callbacks in drivers that have been bound part way
through the recovery process. This is necessary to prevent later stage
handlers from being called when the earlier stage handlers haven't,
which can be confusing for drivers.

However, the flag is set for all devices that are added after boot
time and only cleared at the end of the EEH recovery process. This
results in hot plugged devices erroneously having the flag set during
the first recovery after they are added (causing their driver's
handlers to be incorrectly ignored).

To remedy this, clear the flag at the beginning of recovery
processing. The flag is still cleared at the end of recovery
processing, although it is no longer really necessary.

Also clear the flag during eeh_handle_special_event(), for the same
reasons.

Signed-off-by: Sam Bobroff <redacted>
---
v2 * Also clear EEH_DEV_NO_HANDLER in eeh_handle_special_event().

 arch/powerpc/kernel/eeh_driver.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
index 6f3ee30565dd..d6f54840a3a9 100644
--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c

@@ -819,6 +819,10 @@ void eeh_handle_normal_event(struct eeh_pe *pe)
 		result = PCI_ERS_RESULT_DISCONNECT;
 	}
 
+	eeh_for_each_pe(pe, tmp_pe)
+		eeh_pe_for_each_dev(tmp_pe, edev, tmp)
+			edev->mode &= ~EEH_DEV_NO_HANDLER;
+
 	/* Walk the various device drivers attached to this slot through
 	 * a reset sequence, giving each an opportunity to do what it needs
 	 * to accomplish the reset.  Each child gets a report of the

@@ -1009,7 +1013,8 @@ void eeh_handle_normal_event(struct eeh_pe *pe)
  */
 void eeh_handle_special_event(void)
 {
-	struct eeh_pe *pe, *phb_pe;
+	struct eeh_pe *pe, *phb_pe, *tmp_pe;
+	struct eeh_dev *edev, *tmp_edev;
 	struct pci_bus *bus;
 	struct pci_controller *hose;
 	unsigned long flags;

@@ -1078,6 +1083,10 @@ void eeh_handle_special_event(void)
 				    (phb_pe->state & EEH_PE_RECOVERING))
 					continue;
 
+				eeh_for_each_pe(pe, tmp_pe)
+					eeh_pe_for_each_dev(tmp_pe, edev, tmp_edev)
+						edev->mode &= ~EEH_DEV_NO_HANDLER;
+
 				/* Notify all devices to be down */
 				eeh_pe_state_clear(pe, EEH_PE_PRI_BUS, true);
 				eeh_set_channel_state(pe, pci_channel_io_perm_failure);

-- 
2.19.0.2.gcad72f5712

Also remove useless comment.

Signed-off-by: Sam Bobroff <redacted>
Reviewed-by: Alexey Kardashevskiy <redacted>
---
 arch/powerpc/kernel/eeh.c                    |  2 +-
 arch/powerpc/platforms/powernv/eeh-powernv.c | 14 ++++++++----
 arch/powerpc/platforms/pseries/eeh_pseries.c | 23 +++++++++++++++-----
 3 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 8d3c36a1f194..b14d89547895 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c

@@ -1291,7 +1291,7 @@ void eeh_add_device_late(struct pci_dev *dev)
 	pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
 	edev = pdn_to_eeh_dev(pdn);
 	if (edev->pdev == dev) {
-		pr_debug("EEH: Already referenced !\n");
+		pr_debug("EEH: Device %s already referenced!\n", pci_name(dev));
 		return;
 	}
 

diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index 6fc1a463b796..0e374cdba961 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c

@@ -50,10 +50,7 @@ void pnv_pcibios_bus_add_device(struct pci_dev *pdev)
 	if (!pdev->is_virtfn)
 		return;
 
-	/*
-	 * The following operations will fail if VF's sysfs files
-	 * aren't created or its resources aren't finalized.
-	 */
+	pr_debug("%s: EEH: Setting up device %s.\n", __func__, pci_name(pdev));
 	eeh_add_device_early(pdn);
 	eeh_add_device_late(pdev);
 	eeh_sysfs_add_device(pdev);

@@ -397,6 +394,10 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
 	int ret;
 	int config_addr = (pdn->busno << 8) | (pdn->devfn);
 
+	pr_debug("%s: probing %04x:%02x:%02x.%01x\n",
+		__func__, hose->global_number, pdn->busno,
+		PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));
+
 	/*
 	 * When probing the root bridge, which doesn't have any
 	 * subordinate PCI devices. We don't have OF node for

@@ -491,6 +492,11 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
 	/* Save memory bars */
 	eeh_save_bars(edev);
 
+	pr_debug("%s: EEH enabled on %02x:%02x.%01x PHB#%x-PE#%x\n",
+		__func__, pdn->busno, PCI_SLOT(pdn->devfn),
+		PCI_FUNC(pdn->devfn), edev->pe->phb->global_number,
+		edev->pe->addr);
+
 	return NULL;
 }
 

diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c
index 7aa50258dd42..ae06878fbdea 100644
--- a/arch/powerpc/platforms/pseries/eeh_pseries.c
+++ b/arch/powerpc/platforms/pseries/eeh_pseries.c

@@ -65,6 +65,8 @@ void pseries_pcibios_bus_add_device(struct pci_dev *pdev)
 	if (!pdev->is_virtfn)
 		return;
 
+	pr_debug("%s: EEH: Setting up device %s.\n", __func__, pci_name(pdev));
+
 	pdn->device_id  =  pdev->device;
 	pdn->vendor_id  =  pdev->vendor;
 	pdn->class_code =  pdev->class;

@@ -251,6 +253,10 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
 	int enable = 0;
 	int ret;
 
+	pr_debug("%s: probing %04x:%02x:%02x.%01x\n",
+		__func__, pdn->phb->global_number, pdn->busno,
+		PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));
+
 	/* Retrieve OF node and eeh device */
 	edev = pdn_to_eeh_dev(pdn);
 	if (!edev || edev->pe)

@@ -294,7 +300,12 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
 
 	/* Enable EEH on the device */
 	ret = eeh_ops->set_option(&pe, EEH_OPT_ENABLE);
-	if (!ret) {
+	if (ret) {
+		pr_debug("%s: EEH failed to enable on %02x:%02x.%01x PHB#%x-PE#%x (code %d)\n",
+			__func__, pdn->busno, PCI_SLOT(pdn->devfn),
+			PCI_FUNC(pdn->devfn), pe.phb->global_number,
+			pe.addr, ret);
+	} else {
 		/* Retrieve PE address */
 		edev->pe_config_addr = eeh_ops->get_pe_addr(&pe);
 		pe.addr = edev->pe_config_addr;

@@ -310,11 +321,6 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
 		if (enable) {
 			eeh_add_flag(EEH_ENABLED);
 			eeh_add_to_parent_pe(edev);
-
-			pr_debug("%s: EEH enabled on %02x:%02x.%01x PHB#%x-PE#%x\n",
-				__func__, pdn->busno, PCI_SLOT(pdn->devfn),
-				PCI_FUNC(pdn->devfn), pe.phb->global_number,
-				pe.addr);
 		} 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

@@ -323,6 +329,11 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
 			edev->pe_config_addr = pdn_to_eeh_dev(pdn->parent)->pe_config_addr;
 			eeh_add_to_parent_pe(edev);
 		}
+		pr_debug("%s: EEH %s on %02x:%02x.%01x PHB#%x-PE#%x (code %d)\n",
+			__func__, (enable ? "enabled" : "unsupported"),
+			pdn->busno, PCI_SLOT(pdn->devfn),
+			PCI_FUNC(pdn->devfn), pe.phb->global_number,
+			pe.addr, ret);
 	}
 
 	/* Save memory bars */

-- 
2.19.0.2.gcad72f5712

Now that EEH support for all devices (on PowerNV and pSeries) is
provided by the pcibios bus add device hooks, eeh_probe_devices() and
eeh_addr_cache_build() are redundant and can be removed.

Move the EEH enabled message into it's own function so that it can be
called from multiple places.

Note that previously on pSeries, useless EEH sysfs files were created
for some devices that did not have EEH support and this change
prevents them from being created.

Signed-off-by: Sam Bobroff <redacted>
---
v2 - As it's so small, merged the enablement message patch into this one (where it's used).
   - Reworked enablement messages.

 arch/powerpc/include/asm/eeh.h               |  7 ++---
 arch/powerpc/kernel/eeh.c                    | 27 ++++++-----------
 arch/powerpc/kernel/eeh_cache.c              | 32 --------------------
 arch/powerpc/platforms/powernv/eeh-powernv.c |  4 +--
 arch/powerpc/platforms/pseries/pci.c         |  3 +-
 5 files changed, 14 insertions(+), 59 deletions(-)

diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
index 12baf1df134c..3994d45ae0d4 100644
--- a/arch/powerpc/include/asm/eeh.h
+++ b/arch/powerpc/include/asm/eeh.h

@@ -283,13 +283,12 @@ struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe);
 
 struct eeh_dev *eeh_dev_init(struct pci_dn *pdn);
 void eeh_dev_phb_init_dynamic(struct pci_controller *phb);
-void eeh_probe_devices(void);
+void eeh_show_enabled(void);
 int __init eeh_ops_register(struct eeh_ops *ops);
 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_addr_cache_build(void);
 void eeh_add_device_early(struct pci_dn *);
 void eeh_add_device_tree_early(struct pci_dn *);
 void eeh_add_device_late(struct pci_dev *);

@@ -333,7 +332,7 @@ static inline bool eeh_enabled(void)
         return false;
 }
 
-static inline void eeh_probe_devices(void) { }
+static inline void eeh_show_enabled(void) { }
 
 static inline void *eeh_dev_init(struct pci_dn *pdn, void *data)
 {

@@ -351,8 +350,6 @@ static inline int eeh_check_failure(const volatile void __iomem *token)
 
 static inline void eeh_addr_cache_init(void) { }
 
-static inline void eeh_addr_cache_build(void) { }
-
 static inline void eeh_add_device_early(struct pci_dn *pdn) { }
 
 static inline void eeh_add_device_tree_early(struct pci_dn *pdn) { }

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 1ed80adb40a1..f905235f0307 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c

@@ -163,6 +163,16 @@ static int __init eeh_setup(char *str)
 }
 __setup("eeh=", eeh_setup);
 
+void eeh_show_enabled(void)
+{
+	if (eeh_has_flag(EEH_FORCE_DISABLED))
+		pr_info("EEH: Recovery disabled by kernel parameter.\n");
+	else if (eeh_has_flag(EEH_ENABLED))
+		pr_info("EEH: Capable adapter found: recovery enabled.\n");
+	else
+		pr_info("EEH: No capable adapters found: recovery disabled.\n");
+}
+
 /*
  * This routine captures assorted PCI configuration space data
  * for the indicated PCI device, and puts them into a buffer

@@ -1156,23 +1166,6 @@ static struct notifier_block eeh_reboot_nb = {
 	.notifier_call = eeh_reboot_notifier,
 };
 
-void eeh_probe_devices(void)
-{
-	struct pci_controller *hose, *tmp;
-	struct pci_dn *pdn;
-
-	/* Enable EEH for all adapters */
-	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
-		pdn = hose->pci_data;
-		traverse_pci_dn(pdn, eeh_ops->probe, NULL);
-	}
-	if (eeh_enabled())
-		pr_info("EEH: PCI Enhanced I/O Error Handling Enabled\n");
-	else
-		pr_info("EEH: No capable adapters found\n");
-
-}
-
 /**
  * eeh_init - EEH initialization
  *

diff --git a/arch/powerpc/kernel/eeh_cache.c b/arch/powerpc/kernel/eeh_cache.c
index f93dd5cf6a39..c40078d036af 100644
--- a/arch/powerpc/kernel/eeh_cache.c
+++ b/arch/powerpc/kernel/eeh_cache.c

@@ -278,38 +278,6 @@ void eeh_addr_cache_init(void)
 	spin_lock_init(&pci_io_addr_cache_root.piar_lock);
 }
 
-/**
- * eeh_addr_cache_build - Build a cache of I/O addresses
- *
- * Build a cache of pci i/o addresses.  This cache will be used to
- * find the pci device that corresponds to a given address.
- * This routine scans all pci busses to build the cache.
- * Must be run late in boot process, after the pci controllers
- * have been scanned for devices (after all device resources are known).
- */
-void eeh_addr_cache_build(void)
-{
-	struct pci_dn *pdn;
-	struct eeh_dev *edev;
-	struct pci_dev *dev = NULL;
-
-	for_each_pci_dev(dev) {
-		pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
-		if (!pdn)
-			continue;
-
-		edev = pdn_to_eeh_dev(pdn);
-		if (!edev)
-			continue;
-
-		dev->dev.archdata.edev = edev;
-		edev->pdev = dev;
-
-		eeh_addr_cache_insert_dev(dev);
-		eeh_sysfs_add_device(dev);
-	}
-}
-
 static int eeh_addr_cache_show(struct seq_file *s, void *v)
 {
 	struct pci_io_addr_range *piar;

diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index 90729d908a54..22a94f4b8586 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c

@@ -259,9 +259,7 @@ int pnv_eeh_post_init(void)
 	struct pnv_phb *phb;
 	int ret = 0;
 
-	/* Probe devices & build address cache */
-	eeh_probe_devices();
-	eeh_addr_cache_build();
+	eeh_show_enabled();
 
 	/* Register OPAL event notifier */
 	eeh_event_irq = opal_event_request(ilog2(OPAL_EVENT_PCI_ERROR));

diff --git a/arch/powerpc/platforms/pseries/pci.c b/arch/powerpc/platforms/pseries/pci.c
index 37a77e57893e..d6a5f4f27507 100644
--- a/arch/powerpc/platforms/pseries/pci.c
+++ b/arch/powerpc/platforms/pseries/pci.c

@@ -242,8 +242,7 @@ void __init pSeries_final_fixup(void)
 
 	pSeries_request_regions();
 
-	eeh_probe_devices();
-	eeh_addr_cache_build();
+	eeh_show_enabled();
 
 #ifdef CONFIG_PCI_IOV
 	ppc_md.pcibios_sriov_enable = pseries_pcibios_sriov_enable;

-- 
2.19.0.2.gcad72f5712

On PowerNV and pSeries, devices currently acquire EEH support from
several different places: Boot-time devices from eeh_probe_devices()
and eeh_addr_cache_build(), Virtual Function devices from the pcibios
bus add device hooks and hot plugged devices from pci_hp_add_devices()
(with other platforms using other methods as well).  Unfortunately,
pSeries machines currently discover hot plugged devices using
pci_rescan_bus(), not pci_hp_add_devices(), and so those devices do
not receive EEH support.

Rather than adding another case for pci_rescan_bus(), this change
widens the scope of the pcibios bus add device hooks so that they can
handle all devices. As a side effect this also supports devices
discovered after manually rescanning via /sys/bus/pci/rescan.

Note that on PowerNV, this change allows the EEH subsystem to become
enabled after boot as long as it has not been forced off, which was
not previously possible (it was already possible on pSeries).

Signed-off-by: Sam Bobroff <redacted>
---
v2 - Dropped changes to the PowerNV PHB EEH flag, instead refactor just enough to
     use the existing flag from multiple places.
   - Merge the little remaining work from the above change into the patch where
     it's used.

 arch/powerpc/kernel/eeh.c                    |  2 +-
 arch/powerpc/kernel/of_platform.c            |  3 +-
 arch/powerpc/platforms/powernv/eeh-powernv.c | 39 +++++++++-----
 arch/powerpc/platforms/pseries/eeh_pseries.c | 54 ++++++++++----------
 4 files changed, 56 insertions(+), 42 deletions(-)

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 4160514d997c..1ed80adb40a1 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c

@@ -1285,7 +1285,7 @@ void eeh_add_device_late(struct pci_dev *dev)
 	struct pci_dn *pdn;
 	struct eeh_dev *edev;
 
-	if (!dev || !eeh_enabled())
+	if (!dev)
 		return;
 
 	pr_debug("EEH: Adding device %s\n", pci_name(dev));

diff --git a/arch/powerpc/kernel/of_platform.c b/arch/powerpc/kernel/of_platform.c
index becaec990140..d5818e9c4069 100644
--- a/arch/powerpc/kernel/of_platform.c
+++ b/arch/powerpc/kernel/of_platform.c

@@ -86,7 +86,8 @@ static int of_pci_phb_probe(struct platform_device *dev)
 	pcibios_claim_one_bus(phb->bus);
 
 	/* Finish EEH setup */
-	eeh_add_device_tree_late(phb->bus);
+	if (!eeh_has_flag(EEH_FORCE_DISABLED))
+		eeh_add_device_tree_late(phb->bus);
 
 	/* Add probed PCI devices to the device model */
 	pci_bus_add_devices(phb->bus);

diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index 0e374cdba961..90729d908a54 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c

@@ -47,7 +47,7 @@ void pnv_pcibios_bus_add_device(struct pci_dev *pdev)
 {
 	struct pci_dn *pdn = pci_get_pdn(pdev);
 
-	if (!pdev->is_virtfn)
+	if (eeh_has_flag(EEH_FORCE_DISABLED))
 		return;
 
 	pr_debug("%s: EEH: Setting up device %s.\n", __func__, pci_name(pdev));

@@ -226,6 +226,25 @@ static const struct file_operations eeh_tree_state_debugfs_ops = {
 
 #endif /* CONFIG_DEBUG_FS */
 
+void pnv_eeh_enable_phbs(void)
+{
+	struct pci_controller *hose;
+	struct pnv_phb *phb;
+
+	list_for_each_entry(hose, &hose_list, list_node) {
+		phb = hose->private_data;
+		/*
+		 * If EEH is enabled, we're going to rely on that.
+		 * Otherwise, we restore to conventional mechanism
+		 * to clear frozen PE during PCI config access.
+		 */
+		if (eeh_enabled())
+			phb->flags |= PNV_PHB_FLAG_EEH;
+		else
+			phb->flags &= ~PNV_PHB_FLAG_EEH;
+	}
+}
+
 /**
  * pnv_eeh_post_init - EEH platform dependent post initialization
  *

@@ -264,19 +283,11 @@ int pnv_eeh_post_init(void)
 	if (!eeh_enabled())
 		disable_irq(eeh_event_irq);
 
+	pnv_eeh_enable_phbs();
+
 	list_for_each_entry(hose, &hose_list, list_node) {
 		phb = hose->private_data;
 
-		/*
-		 * If EEH is enabled, we're going to rely on that.
-		 * Otherwise, we restore to conventional mechanism
-		 * to clear frozen PE during PCI config access.
-		 */
-		if (eeh_enabled())
-			phb->flags |= PNV_PHB_FLAG_EEH;
-		else
-			phb->flags &= ~PNV_PHB_FLAG_EEH;
-
 		/* Create debugfs entries */
 #ifdef CONFIG_DEBUG_FS
 		if (phb->has_dbgfs || !phb->dbgfs)

@@ -487,7 +498,11 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
 	 * Enable EEH explicitly so that we will do EEH check
 	 * while accessing I/O stuff
 	 */
-	eeh_add_flag(EEH_ENABLED);
+	if (!eeh_has_flag(EEH_ENABLED)) {
+		enable_irq(eeh_event_irq);
+		pnv_eeh_enable_phbs();
+		eeh_add_flag(EEH_ENABLED);
+	}
 
 	/* Save memory bars */
 	eeh_save_bars(edev);

diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c
index ae06878fbdea..e68c79164974 100644
--- a/arch/powerpc/platforms/pseries/eeh_pseries.c
+++ b/arch/powerpc/platforms/pseries/eeh_pseries.c

@@ -55,44 +55,44 @@ static int ibm_get_config_addr_info;
 static int ibm_get_config_addr_info2;
 static int ibm_configure_pe;
 
-#ifdef CONFIG_PCI_IOV
 void pseries_pcibios_bus_add_device(struct pci_dev *pdev)
 {
 	struct pci_dn *pdn = pci_get_pdn(pdev);
-	struct pci_dn *physfn_pdn;
-	struct eeh_dev *edev;
 
-	if (!pdev->is_virtfn)
+	if (eeh_has_flag(EEH_FORCE_DISABLED))
 		return;
 
 	pr_debug("%s: EEH: Setting up device %s.\n", __func__, pci_name(pdev));
+#ifdef CONFIG_PCI_IOV
+	if (pdev->is_virtfn) {
+		struct pci_dn *physfn_pdn;
 
-	pdn->device_id  =  pdev->device;
-	pdn->vendor_id  =  pdev->vendor;
-	pdn->class_code =  pdev->class;
-	/*
-	 * Last allow unfreeze return code used for retrieval
-	 * by user space in eeh-sysfs to show the last command
-	 * completion from platform.
-	 */
-	pdn->last_allow_rc =  0;
-	physfn_pdn      =  pci_get_pdn(pdev->physfn);
-	pdn->pe_number  =  physfn_pdn->pe_num_map[pdn->vf_index];
-	edev = pdn_to_eeh_dev(pdn);
-
-	/*
-	 * The following operations will fail if VF's sysfs files
-	 * aren't created or its resources aren't finalized.
-	 */
+		pdn->device_id  =  pdev->device;
+		pdn->vendor_id  =  pdev->vendor;
+		pdn->class_code =  pdev->class;
+		/*
+		 * Last allow unfreeze return code used for retrieval
+		 * by user space in eeh-sysfs to show the last command
+		 * completion from platform.
+		 */
+		pdn->last_allow_rc =  0;
+		physfn_pdn      =  pci_get_pdn(pdev->physfn);
+		pdn->pe_number  =  physfn_pdn->pe_num_map[pdn->vf_index];
+	}
+#endif
 	eeh_add_device_early(pdn);
 	eeh_add_device_late(pdev);
-	edev->pe_config_addr =  (pdn->busno << 16) | (pdn->devfn << 8);
-	eeh_rmv_from_parent_pe(edev); /* Remove as it is adding to bus pe */
-	eeh_add_to_parent_pe(edev);   /* Add as VF PE type */
-	eeh_sysfs_add_device(pdev);
+#ifdef CONFIG_PCI_IOV
+	if (pdev->is_virtfn) {
+		struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
 
-}
+		edev->pe_config_addr =  (pdn->busno << 16) | (pdn->devfn << 8);
+		eeh_rmv_from_parent_pe(edev); /* Remove as it is adding to bus pe */
+		eeh_add_to_parent_pe(edev);   /* Add as VF PE type */
+	}
 #endif
+	eeh_sysfs_add_device(pdev);
+}
 
 /*
  * Buffer for reporting slot-error-detail rtas calls. Its here

@@ -159,10 +159,8 @@ static int pseries_eeh_init(void)
 	/* Set EEH probe mode */
 	eeh_add_flag(EEH_PROBE_MODE_DEVTREE | EEH_ENABLE_IO_FOR_LOG);
 
-#ifdef CONFIG_PCI_IOV
 	/* Set EEH machine dependent code */
 	ppc_md.pcibios_bus_add_device = pseries_pcibios_bus_add_device;
-#endif
 
 	return 0;
 }

-- 
2.19.0.2.gcad72f5712

On Tue, May 7, 2019 at 2:30 PM Sam Bobroff [off-list ref] wrote:

-void eeh_probe_devices(void)
-{
-       struct pci_controller *hose, *tmp;
-       struct pci_dn *pdn;
-
-       /* Enable EEH for all adapters */
-       list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
-               pdn = hose->pci_data;
-               traverse_pci_dn(pdn, eeh_ops->probe, NULL);
-       }
-       if (eeh_enabled())
-               pr_info("EEH: PCI Enhanced I/O Error Handling Enabled\n");
-       else
-               pr_info("EEH: No capable adapters found\n");
-
-}

The one concern I have about this is that PAPR requires us to enable
EEH for the device before we do any config accesses. From PAPR:

R1–7.3.11.1–5. For the EEH option: If a device driver is going to
enable EEH and the platform has not defaulted
to EEH enabled, then it must do so before it does any operations with
its IOA, including any configuration
cycles or Load or Store operations.

So if we want to be strictly compatible we'd need to ensure the
set-eeh-option RTAS call happens before we read the VDID in
pci_scan_device(). The pseries eeh_probe() function does this
currently, but if we defer it until the pcibios call happens we'll
have done a pile of config accesses before then. Maybe it doesn't
matter, but we'd need to do further testing under phyp or work out
some other way to ensure it's done pre-probe.

On 07/05/2019 14:30, Sam Bobroff wrote:

dev_dbg() seems more appropriate.

edev!=NULL here so you could do dev_dbg(&edev->pdev->dev,...) and skip
PCI_SLOT/PCI_FUNC. Or is (edev!=NULL && edev->pdev==NULL) possible (it
could be, just asking)?

Same here. I understand though this one is a cut-n-paste :)

 	}
 
 	/* Save memory bars */

-- 
Alexey

On Tue, Jun 11, 2019 at 03:47:58PM +1000, Alexey Kardashevskiy wrote:

On 07/05/2019 14:30, Sam Bobroff wrote:

quoted

Also remove useless comment.

Signed-off-by: Sam Bobroff <redacted>
Reviewed-by: Alexey Kardashevskiy <redacted>
---
 arch/powerpc/kernel/eeh.c                    |  2 +-
 arch/powerpc/platforms/powernv/eeh-powernv.c | 14 ++++++++----
 arch/powerpc/platforms/pseries/eeh_pseries.c | 23 +++++++++++++++-----
 3 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 8d3c36a1f194..b14d89547895 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c

@@ -1291,7 +1291,7 @@ void eeh_add_device_late(struct pci_dev *dev)
 	pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
 	edev = pdn_to_eeh_dev(pdn);
 	if (edev->pdev == dev) {
-		pr_debug("EEH: Already referenced !\n");
+		pr_debug("EEH: Device %s already referenced!\n", pci_name(dev));
 		return;
 	}
 

diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index 6fc1a463b796..0e374cdba961 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c

@@ -50,10 +50,7 @@ void pnv_pcibios_bus_add_device(struct pci_dev *pdev)
 	if (!pdev->is_virtfn)
 		return;
 
-	/*
-	 * The following operations will fail if VF's sysfs files
-	 * aren't created or its resources aren't finalized.
-	 */
+	pr_debug("%s: EEH: Setting up device %s.\n", __func__, pci_name(pdev));

dev_dbg() seems more appropriate.

Oh! It does, or even pci_debug() :-)

I'll change it if I need to do another version, otherwise I'll clean it
up later.

quoted

 	eeh_add_device_early(pdn);
 	eeh_add_device_late(pdev);
 	eeh_sysfs_add_device(pdev);

@@ -397,6 +394,10 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
 	int ret;
 	int config_addr = (pdn->busno << 8) | (pdn->devfn);
 
+	pr_debug("%s: probing %04x:%02x:%02x.%01x\n",
+		__func__, hose->global_number, pdn->busno,
+		PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));
+
 	/*
 	 * When probing the root bridge, which doesn't have any
 	 * subordinate PCI devices. We don't have OF node for

@@ -491,6 +492,11 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
 	/* Save memory bars */
 	eeh_save_bars(edev);
 
+	pr_debug("%s: EEH enabled on %02x:%02x.%01x PHB#%x-PE#%x\n",
+		__func__, pdn->busno, PCI_SLOT(pdn->devfn),
+		PCI_FUNC(pdn->devfn), edev->pe->phb->global_number,
+		edev->pe->addr);
+
 	return NULL;
 }
 

diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c
index 7aa50258dd42..ae06878fbdea 100644
--- a/arch/powerpc/platforms/pseries/eeh_pseries.c
+++ b/arch/powerpc/platforms/pseries/eeh_pseries.c

@@ -65,6 +65,8 @@ void pseries_pcibios_bus_add_device(struct pci_dev *pdev)
 	if (!pdev->is_virtfn)
 		return;
 
+	pr_debug("%s: EEH: Setting up device %s.\n", __func__, pci_name(pdev));
+
 	pdn->device_id  =  pdev->device;
 	pdn->vendor_id  =  pdev->vendor;
 	pdn->class_code =  pdev->class;

@@ -251,6 +253,10 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
 	int enable = 0;
 	int ret;
 
+	pr_debug("%s: probing %04x:%02x:%02x.%01x\n",
+		__func__, pdn->phb->global_number, pdn->busno,
+		PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));
+
 	/* Retrieve OF node and eeh device */
 	edev = pdn_to_eeh_dev(pdn);
 	if (!edev || edev->pe)

@@ -294,7 +300,12 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
 
 	/* Enable EEH on the device */
 	ret = eeh_ops->set_option(&pe, EEH_OPT_ENABLE);
-	if (!ret) {
+	if (ret) {
+		pr_debug("%s: EEH failed to enable on %02x:%02x.%01x PHB#%x-PE#%x (code %d)\n",
+			__func__, pdn->busno, PCI_SLOT(pdn->devfn),
+			PCI_FUNC(pdn->devfn), pe.phb->global_number,
+			pe.addr, ret);
+	} else {

edev!=NULL here so you could do dev_dbg(&edev->pdev->dev,...) and skip
PCI_SLOT/PCI_FUNC. Or is (edev!=NULL && edev->pdev==NULL) possible (it
could be, just asking)?

I can see that edev will be non-NULL here, but that pr_debug() pattern
(using the PDN information to form the PCI address) is quite common
across the EEH code, so I think rather than changing a couple of
specific cases, I should do a separate cleanup patch and introduce
something like pdn_debug(pdn, "...."). What do you think?

(I don't know exactly when edev->pdev can be NULL.)

quoted

 		/* Retrieve PE address */
 		edev->pe_config_addr = eeh_ops->get_pe_addr(&pe);
 		pe.addr = edev->pe_config_addr;

@@ -310,11 +321,6 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
 		if (enable) {
 			eeh_add_flag(EEH_ENABLED);
 			eeh_add_to_parent_pe(edev);
-
-			pr_debug("%s: EEH enabled on %02x:%02x.%01x PHB#%x-PE#%x\n",
-				__func__, pdn->busno, PCI_SLOT(pdn->devfn),
-				PCI_FUNC(pdn->devfn), pe.phb->global_number,
-				pe.addr);
 		} 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

@@ -323,6 +329,11 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
 			edev->pe_config_addr = pdn_to_eeh_dev(pdn->parent)->pe_config_addr;
 			eeh_add_to_parent_pe(edev);
 		}
+		pr_debug("%s: EEH %s on %02x:%02x.%01x PHB#%x-PE#%x (code %d)\n",
+			__func__, (enable ? "enabled" : "unsupported"),
+			pdn->busno, PCI_SLOT(pdn->devfn),
+			PCI_FUNC(pdn->devfn), pe.phb->global_number,
+			pe.addr, ret);

Same here. I understand though this one is a cut-n-paste :)

quoted

 	}
 
 	/* Save memory bars */

-- 
Alexey

On Wed, Jun 05, 2019 at 03:49:15PM +1000, Oliver wrote:

On Tue, May 7, 2019 at 2:30 PM Sam Bobroff [off-list ref] wrote:

quoted

Now that EEH support for all devices (on PowerNV and pSeries) is
provided by the pcibios bus add device hooks, eeh_probe_devices() and
eeh_addr_cache_build() are redundant and can be removed.

Move the EEH enabled message into it's own function so that it can be
called from multiple places.

Note that previously on pSeries, useless EEH sysfs files were created
for some devices that did not have EEH support and this change
prevents them from being created.

Signed-off-by: Sam Bobroff <redacted>
---
v2 - As it's so small, merged the enablement message patch into this one (where it's used).
   - Reworked enablement messages.

 arch/powerpc/include/asm/eeh.h               |  7 ++---
 arch/powerpc/kernel/eeh.c                    | 27 ++++++-----------
 arch/powerpc/kernel/eeh_cache.c              | 32 --------------------
 arch/powerpc/platforms/powernv/eeh-powernv.c |  4 +--
 arch/powerpc/platforms/pseries/pci.c         |  3 +-
 5 files changed, 14 insertions(+), 59 deletions(-)

diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
index 12baf1df134c..3994d45ae0d4 100644
--- a/arch/powerpc/include/asm/eeh.h
+++ b/arch/powerpc/include/asm/eeh.h

@@ -283,13 +283,12 @@ struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe);

 struct eeh_dev *eeh_dev_init(struct pci_dn *pdn);
 void eeh_dev_phb_init_dynamic(struct pci_controller *phb);
-void eeh_probe_devices(void);
+void eeh_show_enabled(void);
 int __init eeh_ops_register(struct eeh_ops *ops);
 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_addr_cache_build(void);
 void eeh_add_device_early(struct pci_dn *);
 void eeh_add_device_tree_early(struct pci_dn *);
 void eeh_add_device_late(struct pci_dev *);

@@ -333,7 +332,7 @@ static inline bool eeh_enabled(void)
         return false;
 }

-static inline void eeh_probe_devices(void) { }
+static inline void eeh_show_enabled(void) { }

 static inline void *eeh_dev_init(struct pci_dn *pdn, void *data)
 {

@@ -351,8 +350,6 @@ static inline int eeh_check_failure(const volatile void __iomem *token)

 static inline void eeh_addr_cache_init(void) { }

-static inline void eeh_addr_cache_build(void) { }
-
 static inline void eeh_add_device_early(struct pci_dn *pdn) { }

 static inline void eeh_add_device_tree_early(struct pci_dn *pdn) { }

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 1ed80adb40a1..f905235f0307 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c

@@ -163,6 +163,16 @@ static int __init eeh_setup(char *str)
 }
 __setup("eeh=", eeh_setup);

+void eeh_show_enabled(void)
+{
+       if (eeh_has_flag(EEH_FORCE_DISABLED))
+               pr_info("EEH: Recovery disabled by kernel parameter.\n");
+       else if (eeh_has_flag(EEH_ENABLED))
+               pr_info("EEH: Capable adapter found: recovery enabled.\n");
+       else
+               pr_info("EEH: No capable adapters found: recovery disabled.\n");
+}
+
 /*
  * This routine captures assorted PCI configuration space data
  * for the indicated PCI device, and puts them into a buffer

@@ -1156,23 +1166,6 @@ static struct notifier_block eeh_reboot_nb = {
        .notifier_call = eeh_reboot_notifier,
 };

quoted

-void eeh_probe_devices(void)
-{
-       struct pci_controller *hose, *tmp;
-       struct pci_dn *pdn;
-
-       /* Enable EEH for all adapters */
-       list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
-               pdn = hose->pci_data;
-               traverse_pci_dn(pdn, eeh_ops->probe, NULL);
-       }
-       if (eeh_enabled())
-               pr_info("EEH: PCI Enhanced I/O Error Handling Enabled\n");
-       else
-               pr_info("EEH: No capable adapters found\n");
-
-}

The one concern I have about this is that PAPR requires us to enable
EEH for the device before we do any config accesses. From PAPR:

R1–7.3.11.1–5. For the EEH option: If a device driver is going to
enable EEH and the platform has not defaulted
to EEH enabled, then it must do so before it does any operations with
its IOA, including any configuration
cycles or Load or Store operations.

So if we want to be strictly compatible we'd need to ensure the
set-eeh-option RTAS call happens before we read the VDID in
pci_scan_device(). The pseries eeh_probe() function does this
currently, but if we defer it until the pcibios call happens we'll
have done a pile of config accesses before then. Maybe it doesn't
matter, but we'd need to do further testing under phyp or work out
some other way to ensure it's done pre-probe.

Hmm! I had not looked at this specifically, but I don't think I've made
it any worse. The reordering is all underneath pcibios_init(), and it
changes things from this...

	for each PHB: pcibios_scan_phb() and then pci_bus_add_devices().
	pcibios_resource_survey() [calls ppc_md.pcibios_fixup()->eeh_probe_devices()]

... to this:

	for each PHB: pcibios_scan_phb()
	pcibios_resource_survey()
	for each PHB: pci_bus_add_devices()
	ppc_md.pcibios_fixup()->eeh_probe_devices()

So either way, the EEH probe (and therefore setup) happens last. Moving
the probe into pseries_pcibios_bus_add_device() actually moves it a
little earlier than before.

Just for kicks, I instrumented rtas_pci_read_config() and it shows
that there are indeed several accesses before the probe function is
called. Here's the first:

pcibios_init() ->
pcibios_scan_phb() ->
__of_scan_bus() ->
of_scan_pci_dev() ->
of_create_pci_dev() ->
set_pcie_port_type() ->
pci_find_capability()

Most of that is PowerPC specific, and there's already an EEH hack in
of_scan_pci_dev(), so I tried a quick hack to probe there and it does
seem at least boot OK. And it's before any accesses! :-)

What do you think? (Although, I think I'd prefer to leave this as follow
up work.)

quoted

 /**
  * eeh_init - EEH initialization
  *

diff --git a/arch/powerpc/kernel/eeh_cache.c b/arch/powerpc/kernel/eeh_cache.c
index f93dd5cf6a39..c40078d036af 100644
--- a/arch/powerpc/kernel/eeh_cache.c
+++ b/arch/powerpc/kernel/eeh_cache.c

@@ -278,38 +278,6 @@ void eeh_addr_cache_init(void)
        spin_lock_init(&pci_io_addr_cache_root.piar_lock);
 }

-/**
- * eeh_addr_cache_build - Build a cache of I/O addresses
- *
- * Build a cache of pci i/o addresses.  This cache will be used to
- * find the pci device that corresponds to a given address.
- * This routine scans all pci busses to build the cache.
- * Must be run late in boot process, after the pci controllers
- * have been scanned for devices (after all device resources are known).
- */
-void eeh_addr_cache_build(void)
-{
-       struct pci_dn *pdn;
-       struct eeh_dev *edev;
-       struct pci_dev *dev = NULL;
-
-       for_each_pci_dev(dev) {
-               pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
-               if (!pdn)
-                       continue;
-
-               edev = pdn_to_eeh_dev(pdn);
-               if (!edev)
-                       continue;
-
-               dev->dev.archdata.edev = edev;
-               edev->pdev = dev;
-
-               eeh_addr_cache_insert_dev(dev);
-               eeh_sysfs_add_device(dev);
-       }
-}
-
 static int eeh_addr_cache_show(struct seq_file *s, void *v)
 {
        struct pci_io_addr_range *piar;

diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index 90729d908a54..22a94f4b8586 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c

@@ -259,9 +259,7 @@ int pnv_eeh_post_init(void)
        struct pnv_phb *phb;
        int ret = 0;

-       /* Probe devices & build address cache */
-       eeh_probe_devices();
-       eeh_addr_cache_build();
+       eeh_show_enabled();

        /* Register OPAL event notifier */
        eeh_event_irq = opal_event_request(ilog2(OPAL_EVENT_PCI_ERROR));

diff --git a/arch/powerpc/platforms/pseries/pci.c b/arch/powerpc/platforms/pseries/pci.c
index 37a77e57893e..d6a5f4f27507 100644
--- a/arch/powerpc/platforms/pseries/pci.c
+++ b/arch/powerpc/platforms/pseries/pci.c

@@ -242,8 +242,7 @@ void __init pSeries_final_fixup(void)

        pSeries_request_regions();

-       eeh_probe_devices();
-       eeh_addr_cache_build();
+       eeh_show_enabled();

 #ifdef CONFIG_PCI_IOV
        ppc_md.pcibios_sriov_enable = pseries_pcibios_sriov_enable;
--

2.19.0.2.gcad72f5712

On 19/06/2019 14:27, Sam Bobroff wrote:

On Tue, Jun 11, 2019 at 03:47:58PM +1000, Alexey Kardashevskiy wrote:

quoted

On 07/05/2019 14:30, Sam Bobroff wrote:

quoted

Also remove useless comment.

Signed-off-by: Sam Bobroff <redacted>
Reviewed-by: Alexey Kardashevskiy <redacted>
---
 arch/powerpc/kernel/eeh.c                    |  2 +-
 arch/powerpc/platforms/powernv/eeh-powernv.c | 14 ++++++++----
 arch/powerpc/platforms/pseries/eeh_pseries.c | 23 +++++++++++++++-----
 3 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 8d3c36a1f194..b14d89547895 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c

@@ -1291,7 +1291,7 @@ void eeh_add_device_late(struct pci_dev *dev)
 	pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
 	edev = pdn_to_eeh_dev(pdn);
 	if (edev->pdev == dev) {
-		pr_debug("EEH: Already referenced !\n");
+		pr_debug("EEH: Device %s already referenced!\n", pci_name(dev));
 		return;
 	}
 

diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index 6fc1a463b796..0e374cdba961 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c

@@ -50,10 +50,7 @@ void pnv_pcibios_bus_add_device(struct pci_dev *pdev)
 	if (!pdev->is_virtfn)
 		return;
 
-	/*
-	 * The following operations will fail if VF's sysfs files
-	 * aren't created or its resources aren't finalized.
-	 */
+	pr_debug("%s: EEH: Setting up device %s.\n", __func__, pci_name(pdev));

dev_dbg() seems more appropriate.

Oh! It does, or even pci_debug() :-)

I'll change it if I need to do another version, otherwise I'll clean it
up later.

quoted

quoted

 	eeh_add_device_early(pdn);
 	eeh_add_device_late(pdev);
 	eeh_sysfs_add_device(pdev);

@@ -397,6 +394,10 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
 	int ret;
 	int config_addr = (pdn->busno << 8) | (pdn->devfn);
 
+	pr_debug("%s: probing %04x:%02x:%02x.%01x\n",
+		__func__, hose->global_number, pdn->busno,
+		PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));
+
 	/*
 	 * When probing the root bridge, which doesn't have any
 	 * subordinate PCI devices. We don't have OF node for

@@ -491,6 +492,11 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
 	/* Save memory bars */
 	eeh_save_bars(edev);
 
+	pr_debug("%s: EEH enabled on %02x:%02x.%01x PHB#%x-PE#%x\n",
+		__func__, pdn->busno, PCI_SLOT(pdn->devfn),
+		PCI_FUNC(pdn->devfn), edev->pe->phb->global_number,
+		edev->pe->addr);
+
 	return NULL;
 }
 

diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c
index 7aa50258dd42..ae06878fbdea 100644
--- a/arch/powerpc/platforms/pseries/eeh_pseries.c
+++ b/arch/powerpc/platforms/pseries/eeh_pseries.c

@@ -65,6 +65,8 @@ void pseries_pcibios_bus_add_device(struct pci_dev *pdev)
 	if (!pdev->is_virtfn)
 		return;
 
+	pr_debug("%s: EEH: Setting up device %s.\n", __func__, pci_name(pdev));
+
 	pdn->device_id  =  pdev->device;
 	pdn->vendor_id  =  pdev->vendor;
 	pdn->class_code =  pdev->class;

@@ -251,6 +253,10 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
 	int enable = 0;
 	int ret;
 
+	pr_debug("%s: probing %04x:%02x:%02x.%01x\n",
+		__func__, pdn->phb->global_number, pdn->busno,
+		PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));
+
 	/* Retrieve OF node and eeh device */
 	edev = pdn_to_eeh_dev(pdn);
 	if (!edev || edev->pe)

@@ -294,7 +300,12 @@ static void *pseries_eeh_probe(struct pci_dn *pdn, void *data)
 
 	/* Enable EEH on the device */
 	ret = eeh_ops->set_option(&pe, EEH_OPT_ENABLE);
-	if (!ret) {
+	if (ret) {
+		pr_debug("%s: EEH failed to enable on %02x:%02x.%01x PHB#%x-PE#%x (code %d)\n",
+			__func__, pdn->busno, PCI_SLOT(pdn->devfn),
+			PCI_FUNC(pdn->devfn), pe.phb->global_number,
+			pe.addr, ret);
+	} else {

edev!=NULL here so you could do dev_dbg(&edev->pdev->dev,...) and skip
PCI_SLOT/PCI_FUNC. Or is (edev!=NULL && edev->pdev==NULL) possible (it
could be, just asking)?

I can see that edev will be non-NULL here, but that pr_debug() pattern
(using the PDN information to form the PCI address) is quite common
across the EEH code, so I think rather than changing a couple of
specific cases, I should do a separate cleanup patch and introduce
something like pdn_debug(pdn, "...."). What do you think?