From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Subject: s390/pci: introduce clp_get_state
Patch-mainline: v4.13-rc1
Git-commit: 783684f1f60faec09f3ac74c0b12e89bdb182429
References: bnc#1066983, LTC#157731

Description:  PCI: fix hotplug related issues
Symptom:      After serveral cycles of hot-unplug/hotplug the affected
              function stops working or the kernel oopses.
Problem:      Hotplug notifications happen after the fact, meaning it's
              not possible to issue instructions to the function for
              cleanup purposes. Thus we never release the associated
              resources and at some point fail to allocate new ones.
Solution:     During clean up treat some errors as success (e.g. a
              function that's gone can't create an interrupt).
Reproduction: vmcp att pcif XXX to \* ;vmcp det pcif XXX #in a loop

Upstream-Description:

              s390/pci: introduce clp_get_state

              Code handling pci hotplug needs to determine the configuration
              state of a pci function. Implement clp_get_state as a wrapper
              for list pci functions.

              Also change enum zpci_state to match the configuration state
              values.

              Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
              Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
              Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>


Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 arch/s390/include/asm/pci.h |   10 ++++----
 arch/s390/pci/pci_clp.c     |   51 ++++++++++++++++++++++++++++++++++++--------
 2 files changed, 47 insertions(+), 14 deletions(-)

--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -70,11 +70,10 @@ struct zpci_fmb {
 } __packed __aligned(128);
 
 enum zpci_state {
-	ZPCI_FN_STATE_RESERVED,
-	ZPCI_FN_STATE_STANDBY,
-	ZPCI_FN_STATE_CONFIGURED,
-	ZPCI_FN_STATE_ONLINE,
-	NR_ZPCI_FN_STATES,
+	ZPCI_FN_STATE_STANDBY = 0,
+	ZPCI_FN_STATE_CONFIGURED = 1,
+	ZPCI_FN_STATE_RESERVED = 2,
+	ZPCI_FN_STATE_ONLINE = 3,
 };
 
 struct zpci_bar_struct {
@@ -172,6 +171,7 @@ int clp_rescan_pci_devices_simple(void);
 int clp_add_pci_device(u32, u32, int);
 int clp_enable_fh(struct zpci_dev *, u8);
 int clp_disable_fh(struct zpci_dev *);
+int clp_get_state(u32 fid, enum zpci_state *state);
 
 #ifdef CONFIG_PCI
 /* Error handling and recovery */
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -295,8 +295,8 @@ int clp_disable_fh(struct zpci_dev *zdev
 	return rc;
 }
 
-static int clp_list_pci(struct clp_req_rsp_list_pci *rrb,
-			void (*cb)(struct clp_fh_list_entry *entry))
+static int clp_list_pci(struct clp_req_rsp_list_pci *rrb, void *data,
+			void (*cb)(struct clp_fh_list_entry *, void *))
 {
 	u64 resume_token = 0;
 	int entries, i, rc;
@@ -327,13 +327,13 @@ static int clp_list_pci(struct clp_req_r
 
 		resume_token = rrb->response.resume_token;
 		for (i = 0; i < entries; i++)
-			cb(&rrb->response.fh_list[i]);
+			cb(&rrb->response.fh_list[i], data);
 	} while (resume_token);
 out:
 	return rc;
 }
 
-static void __clp_add(struct clp_fh_list_entry *entry)
+static void __clp_add(struct clp_fh_list_entry *entry, void *data)
 {
 	if (!entry->vendor_id)
 		return;
@@ -341,7 +341,7 @@ static void __clp_add(struct clp_fh_list
 	clp_add_pci_device(entry->fid, entry->fh, entry->config_state);
 }
 
-static void __clp_rescan(struct clp_fh_list_entry *entry)
+static void __clp_rescan(struct clp_fh_list_entry *entry, void *data)
 {
 	struct zpci_dev *zdev;
 
@@ -364,7 +364,7 @@ static void __clp_rescan(struct clp_fh_l
 	}
 }
 
-static void __clp_update(struct clp_fh_list_entry *entry)
+static void __clp_update(struct clp_fh_list_entry *entry, void *data)
 {
 	struct zpci_dev *zdev;
 
@@ -387,7 +387,7 @@ int clp_scan_pci_devices(void)
 	if (!rrb)
 		return -ENOMEM;
 
-	rc = clp_list_pci(rrb, __clp_add);
+	rc = clp_list_pci(rrb, NULL, __clp_add);
 
 	clp_free_block(rrb);
 	return rc;
@@ -402,7 +402,7 @@ int clp_rescan_pci_devices(void)
 	if (!rrb)
 		return -ENOMEM;
 
-	rc = clp_list_pci(rrb, __clp_rescan);
+	rc = clp_list_pci(rrb, NULL, __clp_rescan);
 
 	clp_free_block(rrb);
 	return rc;
@@ -417,7 +417,40 @@ int clp_rescan_pci_devices_simple(void)
 	if (!rrb)
 		return -ENOMEM;
 
-	rc = clp_list_pci(rrb, __clp_update);
+	rc = clp_list_pci(rrb, NULL, __clp_update);
+
+	clp_free_block(rrb);
+	return rc;
+}
+
+struct clp_state_data {
+	u32 fid;
+	enum zpci_state state;
+};
+
+static void __clp_get_state(struct clp_fh_list_entry *entry, void *data)
+{
+	struct clp_state_data *sd = data;
+
+	if (entry->fid != sd->fid)
+		return;
+
+	sd->state = entry->config_state;
+}
+
+int clp_get_state(u32 fid, enum zpci_state *state)
+{
+	struct clp_req_rsp_list_pci *rrb;
+	struct clp_state_data sd = {fid, ZPCI_FN_STATE_RESERVED};
+	int rc;
+
+	rrb = clp_alloc_block(GFP_KERNEL);
+	if (!rrb)
+		return -ENOMEM;
+
+	rc = clp_list_pci(rrb, &sd, __clp_get_state);
+	if (!rc)
+		*state = sd.state;
 
 	clp_free_block(rrb);
 	return rc;