[PATCH V5 1/6] PCI: Handle error return from pci_reset_bridge_secondary_bus()

[PATCH V5 1/6] PCI: Handle error return from pci_reset_bridge_secondary_bus()

[Sinan Kaya]

commit 01fd61c0b9bd ("PCI: Add a return type for
pci_reset_bridge_secondary_bus()") added a return value to the function to
return if a device is accessible following a reset. Callers are not
checking the value.

Pass error code up high in the stack if device is not accessible.

Fixes: 01fd61c0b9bd ("PCI: Add a return type for pci_reset_bridge_secondary_bus()")
Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/pci/hotplug/pciehp_hpc.c |  5 +++--
 drivers/pci/pci.c                | 12 ++++++------
 drivers/pci/pcie/aer.c           |  5 +++--
 drivers/pci/pcie/err.c           |  6 ++++--
 4 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 718b607..bbaa211 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -728,6 +728,7 @@ int pciehp_reset_slot(struct slot *slot, int probe)
 	struct controller *ctrl = slot->ctrl;
 	struct pci_dev *pdev = ctrl_dev(ctrl);
 	u16 stat_mask = 0, ctrl_mask = 0;
+	int rc;
 
 	if (probe)
 		return 0;
@@ -745,7 +746,7 @@ int pciehp_reset_slot(struct slot *slot, int probe)
 	if (pciehp_poll_mode)
 		del_timer_sync(&ctrl->poll_timer);
 
-	pci_reset_bridge_secondary_bus(ctrl->pcie->port);
+	rc = pci_reset_bridge_secondary_bus(ctrl->pcie->port);
 
 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask);
 	pcie_write_cmd_nowait(ctrl, ctrl_mask, ctrl_mask);
@@ -753,7 +754,7 @@ int pciehp_reset_slot(struct slot *slot, int probe)
 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL, ctrl_mask);
 	if (pciehp_poll_mode)
 		int_poll_timeout(&ctrl->poll_timer);
-	return 0;
+	return rc;
 }
 
 int pcie_init_notification(struct controller *ctrl)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 97acba7..98d1490 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4253,9 +4253,7 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
 	if (probe)
 		return 0;
 
-	pci_reset_bridge_secondary_bus(dev->bus->self);
-
-	return 0;
+	return pci_reset_bridge_secondary_bus(dev->bus->self);
 }
 
 static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
@@ -4850,6 +4848,8 @@ EXPORT_SYMBOL_GPL(pci_try_reset_slot);
 
 static int pci_bus_reset(struct pci_bus *bus, int probe)
 {
+	int ret;
+
 	if (!bus->self || !pci_bus_resetable(bus))
 		return -ENOTTY;
 
@@ -4860,11 +4860,11 @@ static int pci_bus_reset(struct pci_bus *bus, int probe)
 
 	might_sleep();
 
-	pci_reset_bridge_secondary_bus(bus->self);
+	ret = pci_reset_bridge_secondary_bus(bus->self);
 
 	pci_bus_unlock(bus);
 
-	return 0;
+	return ret;
 }
 
 /**
@@ -4924,7 +4924,7 @@ int pci_try_reset_bus(struct pci_bus *bus)
 
 	if (pci_bus_trylock(bus)) {
 		might_sleep();
-		pci_reset_bridge_secondary_bus(bus->self);
+		rc = pci_reset_bridge_secondary_bus(bus->self);
 		pci_bus_unlock(bus);
 	} else
 		rc = -EAGAIN;
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index a2e8838..bde723d 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1305,6 +1305,7 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 {
 	u32 reg32;
 	int pos;
+	int rc;
 
 	pos = dev->aer_cap;
 
@@ -1313,7 +1314,7 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
 	pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
 
-	pci_reset_bridge_secondary_bus(dev);
+	rc = pci_reset_bridge_secondary_bus(dev);
 	pci_printk(KERN_DEBUG, dev, "Root Port link has been reset\n");
 
 	/* Clear Root Error Status */
@@ -1325,7 +1326,7 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 	reg32 |= ROOT_PORT_INTR_ON_MESG_MASK;
 	pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
 
-	return PCI_ERS_RESULT_RECOVERED;
+	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
 }
 
 /**
diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index f7ce0cb..03075cf 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -175,9 +175,11 @@ static int report_resume(struct pci_dev *dev, void *data)
  */
 static pci_ers_result_t default_reset_link(struct pci_dev *dev)
 {
-	pci_reset_bridge_secondary_bus(dev);
+	int rc;
+
+	rc = pci_reset_bridge_secondary_bus(dev);
 	pci_printk(KERN_DEBUG, dev, "downstream link has been reset\n");
-	return PCI_ERS_RESULT_RECOVERED;
+	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
 }
 
 static pci_ers_result_t reset_link(struct pci_dev *dev, u32 service)
-- 
2.7.4

[PATCH V5 2/6] IB/hfi1: Use pci_try_reset_bus() for initiating pci secondary bus reset

[Sinan Kaya]

Getting ready to hide pci_reset_bridge_secondary_bus() from the drivers.
pci_reset_bridge_secondary_bus() should only be used internally by the
PCI code itself.

Other drivers should rely on higher level pci_try_reset_bus() API.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/infiniband/hw/hfi1/pcie.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/pcie.c b/drivers/infiniband/hw/hfi1/pcie.c
index 4d4371b..4570c4d 100644
--- a/drivers/infiniband/hw/hfi1/pcie.c
+++ b/drivers/infiniband/hw/hfi1/pcie.c
@@ -905,9 +905,7 @@ static int trigger_sbr(struct hfi1_devdata *dd)
 	 * delay after a reset is required.  Per spec requirements,
 	 * the link is either working or not after that point.
 	 */
-	pci_reset_bridge_secondary_bus(dev->bus->self);
-
-	return 0;
+	return pci_try_reset_bus(dev->bus);
 }
 
 /*
-- 
2.7.4

[PATCH V5 3/6] PCI: Hide pci_reset_bridge_secondary_bus() from drivers

[Sinan Kaya]

Rename pci_reset_bridge_secondary_bus() to pci_bridge_secondary_bus_reset()
and move the declartation from linux/pci.h to drivers/pci.h to be used
internally in PCI directory only.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/pci/hotplug/pciehp_hpc.c |  2 +-
 drivers/pci/pci.c                | 11 +++++------
 drivers/pci/pci.h                |  1 +
 drivers/pci/pcie/aer.c           |  2 +-
 drivers/pci/pcie/err.c           |  2 +-
 include/linux/pci.h              |  1 -
 6 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index bbaa211..8dae232 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -746,7 +746,7 @@ int pciehp_reset_slot(struct slot *slot, int probe)
 	if (pciehp_poll_mode)
 		del_timer_sync(&ctrl->poll_timer);
 
-	rc = pci_reset_bridge_secondary_bus(ctrl->pcie->port);
+	rc = pci_bridge_secondary_bus_reset(ctrl->pcie->port);
 
 	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask);
 	pcie_write_cmd_nowait(ctrl, ctrl_mask, ctrl_mask);
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 98d1490..236220c 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4224,19 +4224,18 @@ void __weak pcibios_reset_secondary_bus(struct pci_dev *dev)
 }
 
 /**
- * pci_reset_bridge_secondary_bus - Reset the secondary bus on a PCI bridge.
+ * pci_bridge_secondary_bus_reset - Reset the secondary bus on a PCI bridge.
  * @dev: Bridge device
  *
  * Use the bridge control register to assert reset on the secondary bus.
  * Devices on the secondary bus are left in power-on state.
  */
-int pci_reset_bridge_secondary_bus(struct pci_dev *dev)
+int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
 {
 	pcibios_reset_secondary_bus(dev);
 
 	return pci_dev_wait(dev, "bus reset", PCIE_RESET_READY_POLL_MS);
 }
-EXPORT_SYMBOL_GPL(pci_reset_bridge_secondary_bus);
 
 static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
 {
@@ -4253,7 +4252,7 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
 	if (probe)
 		return 0;
 
-	return pci_reset_bridge_secondary_bus(dev->bus->self);
+	return pci_bridge_secondary_bus_reset(dev->bus->self);
 }
 
 static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
@@ -4860,7 +4859,7 @@ static int pci_bus_reset(struct pci_bus *bus, int probe)
 
 	might_sleep();
 
-	ret = pci_reset_bridge_secondary_bus(bus->self);
+	ret = pci_bridge_secondary_bus_reset(bus->self);
 
 	pci_bus_unlock(bus);
 
@@ -4924,7 +4923,7 @@ int pci_try_reset_bus(struct pci_bus *bus)
 
 	if (pci_bus_trylock(bus)) {
 		might_sleep();
-		rc = pci_reset_bridge_secondary_bus(bus->self);
+		rc = pci_bridge_secondary_bus_reset(bus->self);
 		pci_bus_unlock(bus);
 	} else
 		rc = -EAGAIN;
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index c358e7a0..f784263 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -33,6 +33,7 @@ int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vmai,
 		  enum pci_mmap_api mmap_api);
 
 int pci_probe_reset_function(struct pci_dev *dev);
+int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
 
 /**
  * struct pci_platform_pm_ops - Firmware PM callbacks
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index bde723d..8c12efc 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1314,7 +1314,7 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
 	pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32);
 
-	rc = pci_reset_bridge_secondary_bus(dev);
+	rc = pci_bridge_secondary_bus_reset(dev);
 	pci_printk(KERN_DEBUG, dev, "Root Port link has been reset\n");
 
 	/* Clear Root Error Status */
diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 03075cf..ae72f88 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -177,7 +177,7 @@ static pci_ers_result_t default_reset_link(struct pci_dev *dev)
 {
 	int rc;
 
-	rc = pci_reset_bridge_secondary_bus(dev);
+	rc = pci_bridge_secondary_bus_reset(dev);
 	pci_printk(KERN_DEBUG, dev, "downstream link has been reset\n");
 	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
 }
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 340029b..6b12ce2 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1102,7 +1102,6 @@ int pci_reset_bus(struct pci_bus *bus);
 int pci_try_reset_bus(struct pci_bus *bus);
 void pci_reset_secondary_bus(struct pci_dev *dev);
 void pcibios_reset_secondary_bus(struct pci_dev *dev);
-int pci_reset_bridge_secondary_bus(struct pci_dev *dev);
 void pci_update_resource(struct pci_dev *dev, int resno);
 int __must_check pci_assign_resource(struct pci_dev *dev, int i);
 int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align);
-- 
2.7.4

[PATCH V5 4/6] PCI: Unify try slot and bus reset API

[Sinan Kaya]

Drivers are expected to call pci_try_reset_slot() or pci_try_reset_bus() by
querying if a system supports hotplug or not. A survey showed that most
drivers don't do this and we are leaking hotplug capability to the user.

Hide pci_try_slot_reset() from drivers and embed into pci_try_bus_reset().
Change pci_try_reset_bus() parameter from struct pci_bus to struct pci_dev.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/infiniband/hw/hfi1/pcie.c |  2 +-
 drivers/pci/pci.c                 | 21 ++++++++++++++++-----
 drivers/vfio/pci/vfio_pci.c       |  6 ++----
 include/linux/pci.h               |  3 +--
 4 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/pcie.c b/drivers/infiniband/hw/hfi1/pcie.c
index 4570c4d..df4f2d3 100644
--- a/drivers/infiniband/hw/hfi1/pcie.c
+++ b/drivers/infiniband/hw/hfi1/pcie.c
@@ -905,7 +905,7 @@ static int trigger_sbr(struct hfi1_devdata *dd)
 	 * delay after a reset is required.  Per spec requirements,
 	 * the link is either working or not after that point.
 	 */
-	return pci_try_reset_bus(dev->bus);
+	return pci_try_reset_bus(dev);
 }
 
 /*
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 236220c..a31e6db 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4817,12 +4817,12 @@ int pci_reset_slot(struct pci_slot *slot)
 EXPORT_SYMBOL_GPL(pci_reset_slot);
 
 /**
- * pci_try_reset_slot - Try to reset a PCI slot
+ * __pci_try_reset_slot - Try to reset a PCI slot
  * @slot: PCI slot to reset
  *
  * Same as above except return -EAGAIN if the slot cannot be locked
  */
-int pci_try_reset_slot(struct pci_slot *slot)
+static int __pci_try_reset_slot(struct pci_slot *slot)
 {
 	int rc;
 
@@ -4843,7 +4843,6 @@ int pci_try_reset_slot(struct pci_slot *slot)
 
 	return rc;
 }
-EXPORT_SYMBOL_GPL(pci_try_reset_slot);
 
 static int pci_bus_reset(struct pci_bus *bus, int probe)
 {
@@ -4906,12 +4905,12 @@ int pci_reset_bus(struct pci_bus *bus)
 EXPORT_SYMBOL_GPL(pci_reset_bus);
 
 /**
- * pci_try_reset_bus - Try to reset a PCI bus
+ * __pci_try_reset_bus - Try to reset a PCI bus
  * @bus: top level PCI bus to reset
  *
  * Same as above except return -EAGAIN if the bus cannot be locked
  */
-int pci_try_reset_bus(struct pci_bus *bus)
+static int __pci_try_reset_bus(struct pci_bus *bus)
 {
 	int rc;
 
@@ -4932,6 +4931,18 @@ int pci_try_reset_bus(struct pci_bus *bus)
 
 	return rc;
 }
+
+/**
+ * pci_try_reset_bus - Try to reset a PCI bus
+ * @pdev: top level PCI device to reset via slot/bus
+ *
+ * Same as above except return -EAGAIN if the bus cannot be locked
+ */
+int pci_try_reset_bus(struct pci_dev *pdev)
+{
+	return pci_probe_reset_slot(pdev->slot) ?
+	    __pci_try_reset_slot(pdev->slot) : __pci_try_reset_bus(pdev->bus);
+}
 EXPORT_SYMBOL_GPL(pci_try_reset_bus);
 
 /**
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index b423a30..71018ec 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -1010,8 +1010,7 @@ static long vfio_pci_ioctl(void *device_data,
 						    &info, slot);
 		if (!ret)
 			/* User has access, do the reset */
-			ret = slot ? pci_try_reset_slot(vdev->pdev->slot) :
-				     pci_try_reset_bus(vdev->pdev->bus);
+			ret = pci_try_reset_bus(vdev->pdev);
 
 hot_reset_release:
 		for (i--; i >= 0; i--)
@@ -1373,8 +1372,7 @@ static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev)
 	}
 
 	if (needs_reset)
-		ret = slot ? pci_try_reset_slot(vdev->pdev->slot) :
-			     pci_try_reset_bus(vdev->pdev->bus);
+		ret = pci_try_reset_bus(vdev->pdev);
 
 put_devs:
 	for (i = 0; i < devs.cur_index; i++) {
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 6b12ce2..f5c85b6 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1096,10 +1096,9 @@ int pci_reset_function_locked(struct pci_dev *dev);
 int pci_try_reset_function(struct pci_dev *dev);
 int pci_probe_reset_slot(struct pci_slot *slot);
 int pci_reset_slot(struct pci_slot *slot);
-int pci_try_reset_slot(struct pci_slot *slot);
 int pci_probe_reset_bus(struct pci_bus *bus);
 int pci_reset_bus(struct pci_bus *bus);
-int pci_try_reset_bus(struct pci_bus *bus);
+int pci_try_reset_bus(struct pci_dev *dev);
 void pci_reset_secondary_bus(struct pci_dev *dev);
 void pcibios_reset_secondary_bus(struct pci_dev *dev);
 void pci_update_resource(struct pci_dev *dev, int resno);
-- 
2.7.4

[PATCH V5 5/6] PCI: Deprecate pci_reset_bus() and pci_reset_slot() functions

[Sinan Kaya]

pci_reset_bus() and pci_reset_slot() functions are not being used by
any code. Remove them from the kernel in favor of pci_try_reset_bus()
and pci_try_reset_slot() functions.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/pci/pci.c   | 55 ++---------------------------------------------------
 include/linux/pci.h |  2 --
 2 files changed, 2 insertions(+), 55 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index a31e6db..7e3f2e9 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4784,9 +4784,9 @@ int pci_probe_reset_slot(struct pci_slot *slot)
 EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
 
 /**
- * pci_reset_slot - reset a PCI slot
+ * __pci_try_reset_slot - Try to reset a PCI slot
  * @slot: PCI slot to reset
- *
+ *`
  * A PCI bus may host multiple slots, each slot may support a reset mechanism
  * independent of other slots.  For instance, some slots may support slot power
  * control.  In the case of a 1:1 bus to slot architecture, this function may
@@ -4796,30 +4796,6 @@ EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
  * through this function.  PCI config space of all devices in the slot and
  * behind the slot is saved before and restored after reset.
  *
- * Return 0 on success, non-zero on error.
- */
-int pci_reset_slot(struct pci_slot *slot)
-{
-	int rc;
-
-	rc = pci_slot_reset(slot, 1);
-	if (rc)
-		return rc;
-
-	pci_slot_save_and_disable(slot);
-
-	rc = pci_slot_reset(slot, 0);
-
-	pci_slot_restore(slot);
-
-	return rc;
-}
-EXPORT_SYMBOL_GPL(pci_reset_slot);
-
-/**
- * __pci_try_reset_slot - Try to reset a PCI slot
- * @slot: PCI slot to reset
- *
  * Same as above except return -EAGAIN if the slot cannot be locked
  */
 static int __pci_try_reset_slot(struct pci_slot *slot)
@@ -4878,33 +4854,6 @@ int pci_probe_reset_bus(struct pci_bus *bus)
 EXPORT_SYMBOL_GPL(pci_probe_reset_bus);
 
 /**
- * pci_reset_bus - reset a PCI bus
- * @bus: top level PCI bus to reset
- *
- * Do a bus reset on the given bus and any subordinate buses, saving
- * and restoring state of all devices.
- *
- * Return 0 on success, non-zero on error.
- */
-int pci_reset_bus(struct pci_bus *bus)
-{
-	int rc;
-
-	rc = pci_bus_reset(bus, 1);
-	if (rc)
-		return rc;
-
-	pci_bus_save_and_disable(bus);
-
-	rc = pci_bus_reset(bus, 0);
-
-	pci_bus_restore(bus);
-
-	return rc;
-}
-EXPORT_SYMBOL_GPL(pci_reset_bus);
-
-/**
  * __pci_try_reset_bus - Try to reset a PCI bus
  * @bus: top level PCI bus to reset
  *
diff --git a/include/linux/pci.h b/include/linux/pci.h
index f5c85b6..ad0c89a 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1095,9 +1095,7 @@ int pci_reset_function(struct pci_dev *dev);
 int pci_reset_function_locked(struct pci_dev *dev);
 int pci_try_reset_function(struct pci_dev *dev);
 int pci_probe_reset_slot(struct pci_slot *slot);
-int pci_reset_slot(struct pci_slot *slot);
 int pci_probe_reset_bus(struct pci_bus *bus);
-int pci_reset_bus(struct pci_bus *bus);
 int pci_try_reset_bus(struct pci_dev *dev);
 void pci_reset_secondary_bus(struct pci_dev *dev);
 void pcibios_reset_secondary_bus(struct pci_dev *dev);
-- 
2.7.4

Re: [PATCH V5 5/6] PCI: Deprecate pci_reset_bus() and pci_reset_slot() functions

[Bjorn Helgaas]

On Mon, Jul 02, 2018 at 06:58:54PM -0400, Sinan Kaya wrote:
> pci_reset_bus() and pci_reset_slot() functions are not being used by
> any code. Remove them from the kernel in favor of pci_try_reset_bus()
> and pci_try_reset_slot() functions.
> 
> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> ---
>  drivers/pci/pci.c   | 55 ++---------------------------------------------------
>  include/linux/pci.h |  2 --
>  2 files changed, 2 insertions(+), 55 deletions(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index a31e6db..7e3f2e9 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -4784,9 +4784,9 @@ int pci_probe_reset_slot(struct pci_slot *slot)
>  EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
>  
>  /**
> - * pci_reset_slot - reset a PCI slot
> + * __pci_try_reset_slot - Try to reset a PCI slot
>   * @slot: PCI slot to reset
> - *
> + *`

Is this "*`" intentional or a typo?  I can't find it in kernel-doc.rst
(but it's full of ` and maybe I missed it).

I do see a few other occurrences in the code, although they look like
typos to me:

  $ git grep "\*\`" | grep -v Documentation
  arch/mips/cavium-octeon/octeon-usb.c:	 *`	0x1 = Big endian
  arch/mips/cavium-octeon/octeon-usb.c:	 *`	0x1 = Big endian
  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c:/*`

Re: [PATCH V5 5/6] PCI: Deprecate pci_reset_bus() and pci_reset_slot() functions

[Sinan Kaya]

On 7/18/2018 3:30 PM, Bjorn Helgaas wrote:
> On Mon, Jul 02, 2018 at 06:58:54PM -0400, Sinan Kaya wrote:
>> pci_reset_bus() and pci_reset_slot() functions are not being used by
>> any code. Remove them from the kernel in favor of pci_try_reset_bus()
>> and pci_try_reset_slot() functions.
>>
>> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
>> ---
>>   drivers/pci/pci.c   | 55 ++---------------------------------------------------
>>   include/linux/pci.h |  2 --
>>   2 files changed, 2 insertions(+), 55 deletions(-)
>>
>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>> index a31e6db..7e3f2e9 100644
>> --- a/drivers/pci/pci.c
>> +++ b/drivers/pci/pci.c
>> @@ -4784,9 +4784,9 @@ int pci_probe_reset_slot(struct pci_slot *slot)
>>   EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
>>   
>>   /**
>> - * pci_reset_slot - reset a PCI slot
>> + * __pci_try_reset_slot - Try to reset a PCI slot
>>    * @slot: PCI slot to reset
>> - *
>> + *`
> 
> Is this "*`" intentional or a typo?  I can't find it in kernel-doc.rst
> (but it's full of ` and maybe I missed it).

Typo.

> 
> I do see a few other occurrences in the code, although they look like
> typos to me:
> 
>    $ git grep "\*\`" | grep -v Documentation
>    arch/mips/cavium-octeon/octeon-usb.c:	 *`	0x1 = Big endian
>    arch/mips/cavium-octeon/octeon-usb.c:	 *`	0x1 = Big endian
>    drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c:/*`
> 

Re: [PATCH V5 5/6] PCI: Deprecate pci_reset_bus() and pci_reset_slot() functions

[Bjorn Helgaas]

On Wed, Jul 18, 2018 at 03:36:29PM -0700, Sinan Kaya wrote:
> On 7/18/2018 3:30 PM, Bjorn Helgaas wrote:
> > On Mon, Jul 02, 2018 at 06:58:54PM -0400, Sinan Kaya wrote:
> > > pci_reset_bus() and pci_reset_slot() functions are not being used by
> > > any code. Remove them from the kernel in favor of pci_try_reset_bus()
> > > and pci_try_reset_slot() functions.
> > > 
> > > Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> > > ---
> > >   drivers/pci/pci.c   | 55 ++---------------------------------------------------
> > >   include/linux/pci.h |  2 --
> > >   2 files changed, 2 insertions(+), 55 deletions(-)
> > > 
> > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> > > index a31e6db..7e3f2e9 100644
> > > --- a/drivers/pci/pci.c
> > > +++ b/drivers/pci/pci.c
> > > @@ -4784,9 +4784,9 @@ int pci_probe_reset_slot(struct pci_slot *slot)
> > >   EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
> > >   /**
> > > - * pci_reset_slot - reset a PCI slot
> > > + * __pci_try_reset_slot - Try to reset a PCI slot
> > >    * @slot: PCI slot to reset
> > > - *
> > > + *`
> > 
> > Is this "*`" intentional or a typo?  I can't find it in kernel-doc.rst
> > (but it's full of ` and maybe I missed it).
> 
> Typo.

Great, I fixed it.

[PATCH V5 6/6] PCI: Rename pci_try_reset_bus() to pci_reset_bus()

[Sinan Kaya]

Now that the old implementation of pci_reset_bus() is gone, replace
pci_try_reset_bus() with pci_reset_bus().

Compared to the old implementation, new code will fail immmediately with
-EAGAIN if object lock cannot be obtained.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/infiniband/hw/hfi1/pcie.c |  2 +-
 drivers/pci/pci.c                 | 16 ++++++++--------
 drivers/vfio/pci/vfio_pci.c       |  4 ++--
 include/linux/pci.h               |  2 +-
 4 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/pcie.c b/drivers/infiniband/hw/hfi1/pcie.c
index df4f2d3..baf7c32 100644
--- a/drivers/infiniband/hw/hfi1/pcie.c
+++ b/drivers/infiniband/hw/hfi1/pcie.c
@@ -905,7 +905,7 @@ static int trigger_sbr(struct hfi1_devdata *dd)
 	 * delay after a reset is required.  Per spec requirements,
 	 * the link is either working or not after that point.
 	 */
-	return pci_try_reset_bus(dev);
+	return pci_reset_bus(dev);
 }
 
 /*
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 7e3f2e9..bd19350 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4784,7 +4784,7 @@ int pci_probe_reset_slot(struct pci_slot *slot)
 EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
 
 /**
- * __pci_try_reset_slot - Try to reset a PCI slot
+ * __pci_reset_slot - Try to reset a PCI slot
  * @slot: PCI slot to reset
  *`
  * A PCI bus may host multiple slots, each slot may support a reset mechanism
@@ -4798,7 +4798,7 @@ EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
  *
  * Same as above except return -EAGAIN if the slot cannot be locked
  */
-static int __pci_try_reset_slot(struct pci_slot *slot)
+static int __pci_reset_slot(struct pci_slot *slot)
 {
 	int rc;
 
@@ -4854,12 +4854,12 @@ int pci_probe_reset_bus(struct pci_bus *bus)
 EXPORT_SYMBOL_GPL(pci_probe_reset_bus);
 
 /**
- * __pci_try_reset_bus - Try to reset a PCI bus
+ * __pci_reset_bus - Try to reset a PCI bus
  * @bus: top level PCI bus to reset
  *
  * Same as above except return -EAGAIN if the bus cannot be locked
  */
-static int __pci_try_reset_bus(struct pci_bus *bus)
+static int __pci_reset_bus(struct pci_bus *bus)
 {
 	int rc;
 
@@ -4882,17 +4882,17 @@ static int __pci_try_reset_bus(struct pci_bus *bus)
 }
 
 /**
- * pci_try_reset_bus - Try to reset a PCI bus
+ * pci_reset_bus - Try to reset a PCI bus
  * @pdev: top level PCI device to reset via slot/bus
  *
  * Same as above except return -EAGAIN if the bus cannot be locked
  */
-int pci_try_reset_bus(struct pci_dev *pdev)
+int pci_reset_bus(struct pci_dev *pdev)
 {
 	return pci_probe_reset_slot(pdev->slot) ?
-	    __pci_try_reset_slot(pdev->slot) : __pci_try_reset_bus(pdev->bus);
+	    __pci_reset_slot(pdev->slot) : __pci_reset_bus(pdev->bus);
 }
-EXPORT_SYMBOL_GPL(pci_try_reset_bus);
+EXPORT_SYMBOL_GPL(pci_reset_bus);
 
 /**
  * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
index 71018ec..345c0dc 100644
--- a/drivers/vfio/pci/vfio_pci.c
+++ b/drivers/vfio/pci/vfio_pci.c
@@ -1010,7 +1010,7 @@ static long vfio_pci_ioctl(void *device_data,
 						    &info, slot);
 		if (!ret)
 			/* User has access, do the reset */
-			ret = pci_try_reset_bus(vdev->pdev);
+			ret = pci_reset_bus(vdev->pdev);
 
 hot_reset_release:
 		for (i--; i >= 0; i--)
@@ -1372,7 +1372,7 @@ static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev)
 	}
 
 	if (needs_reset)
-		ret = pci_try_reset_bus(vdev->pdev);
+		ret = pci_reset_bus(vdev->pdev);
 
 put_devs:
 	for (i = 0; i < devs.cur_index; i++) {
diff --git a/include/linux/pci.h b/include/linux/pci.h
index ad0c89a..79a2c27 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1096,7 +1096,7 @@ int pci_reset_function_locked(struct pci_dev *dev);
 int pci_try_reset_function(struct pci_dev *dev);
 int pci_probe_reset_slot(struct pci_slot *slot);
 int pci_probe_reset_bus(struct pci_bus *bus);
-int pci_try_reset_bus(struct pci_dev *dev);
+int pci_reset_bus(struct pci_dev *dev);
 void pci_reset_secondary_bus(struct pci_dev *dev);
 void pcibios_reset_secondary_bus(struct pci_dev *dev);
 void pci_update_resource(struct pci_dev *dev, int resno);
-- 
2.7.4