[SRU][J:linux-bluefield][PATCH v4 3/6] UBUNTU: SAUCE: vfio_pci: Do not open code pci_try_reset_function()

[William Tu]

From: Jason Gunthorpe <jgg at nvidia.com>

BugLink: https://bugs.launchpad.net/bugs/2077887

FLR triggered by an emulated config space write should not behave
differently from a FLR triggered by VFIO_DEVICE_RESET, currently the
config space path misses the power management.

Consolidate all the call sites to invoke a single function.

Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
Signed-off-by: William Tu <witu at nvidia.com>
---
 drivers/vfio/pci/vfio_pci_config.c | 14 +++-------
 drivers/vfio/pci/vfio_pci_core.c   | 41 +++++++++++++-----------------
 drivers/vfio/pci/vfio_pci_priv.h   |  7 +++++
 3 files changed, 28 insertions(+), 34 deletions(-)
 create mode 100644 drivers/vfio/pci/vfio_pci_priv.h

diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
index 6e58b4bf7a60..78c626b8907d 100644
--- a/drivers/vfio/pci/vfio_pci_config.c
+++ b/drivers/vfio/pci/vfio_pci_config.c
@@ -857,11 +857,8 @@ static int vfio_exp_config_write(struct vfio_pci_core_device *vdev, int pos,
 						 pos - offset + PCI_EXP_DEVCAP,
 						 &cap);
 
-		if (!ret && (cap & PCI_EXP_DEVCAP_FLR)) {
-			vfio_pci_zap_and_down_write_memory_lock(vdev);
-			pci_try_reset_function(vdev->pdev);
-			up_write(&vdev->memory_lock);
-		}
+		if (!ret && (cap & PCI_EXP_DEVCAP_FLR))
+			vfio_pci_try_reset_function(vdev);
 	}
 
 	/*
@@ -939,11 +936,8 @@ static int vfio_af_config_write(struct vfio_pci_core_device *vdev, int pos,
 						pos - offset + PCI_AF_CAP,
 						&cap);
 
-		if (!ret && (cap & PCI_AF_CAP_FLR) && (cap & PCI_AF_CAP_TP)) {
-			vfio_pci_zap_and_down_write_memory_lock(vdev);
-			pci_try_reset_function(vdev->pdev);
-			up_write(&vdev->memory_lock);
-		}
+		if (!ret && (cap & PCI_AF_CAP_FLR) && (cap & PCI_AF_CAP_TP))
+			vfio_pci_try_reset_function(vdev);
 	}
 
 	return count;
diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 4f1aceadd4fb..5904801f6f77 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -29,6 +29,8 @@
 
 #include <linux/vfio_pci_core.h>
 
+#include "vfio_pci_priv.h"
+
 #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson at redhat.com>"
 #define DRIVER_DESC "core driver for VFIO based PCI devices"
 
@@ -648,6 +650,20 @@ int vfio_pci_register_dev_region(struct vfio_pci_core_device *vdev,
 }
 EXPORT_SYMBOL_GPL(vfio_pci_register_dev_region);
 
+int vfio_pci_try_reset_function(struct vfio_pci_core_device *vdev)
+{
+	int ret;
+
+	if (!vdev->reset_works)
+		return -EINVAL;
+
+	vfio_pci_zap_and_down_write_memory_lock(vdev);
+	ret = pci_try_reset_function(vdev->pdev);
+	up_write(&vdev->memory_lock);
+
+	return ret;
+}
+
 long vfio_pci_core_ioctl(struct vfio_device *core_vdev, unsigned int cmd,
 		unsigned long arg)
 {
@@ -929,30 +945,7 @@ long vfio_pci_core_ioctl(struct vfio_device *core_vdev, unsigned int cmd,
 		return ret;
 
 	} else if (cmd == VFIO_DEVICE_RESET) {
-		int ret;
-
-		if (!vdev->reset_works)
-			return -EINVAL;
-
-		vfio_pci_zap_and_down_write_memory_lock(vdev);
-
-		/*
-		 * This function can be invoked while the power state is non-D0.
-		 * If pci_try_reset_function() has been called while the power
-		 * state is non-D0, then pci_try_reset_function() will
-		 * internally set the power state to D0 without vfio driver
-		 * involvement. For the devices which have NoSoftRst-, the
-		 * reset function can cause the PCI config space reset without
-		 * restoring the original state (saved locally in
-		 * 'vdev->pm_save').
-		 */
-		vfio_pci_set_power_state(vdev, PCI_D0);
-
-		ret = pci_try_reset_function(vdev->pdev);
-		up_write(&vdev->memory_lock);
-
-		return ret;
-
+		return vfio_pci_try_reset_function(vdev);
 	} else if (cmd == VFIO_DEVICE_GET_PCI_HOT_RESET_INFO) {
 		struct vfio_pci_hot_reset_info hdr;
 		struct vfio_pci_fill_info fill = { 0 };
diff --git a/drivers/vfio/pci/vfio_pci_priv.h b/drivers/vfio/pci/vfio_pci_priv.h
new file mode 100644
index 000000000000..4971cd95b431
--- /dev/null
+++ b/drivers/vfio/pci/vfio_pci_priv.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef VFIO_PCI_PRIV_H
+#define VFIO_PCI_PRIV_H
+
+int vfio_pci_try_reset_function(struct vfio_pci_core_device *vdev);
+
+#endif
-- 
2.34.1