git: 30960c51e646 - stable/13 - LinuxKPI: return an address string in pci_name()

The branch stable/13 has been updated by bz:

URL: https://cgit.FreeBSD.org/src/commit/?id=30960c51e646c51134fcb72e0adc881f36a41c38

commit 30960c51e646c51134fcb72e0adc881f36a41c38
Author:     Val Packett <val@packett.cool>
AuthorDate: 2023-02-06 21:50:13 +0000
Commit:     Bjoern A. Zeeb <bz@FreeBSD.org>
CommitDate: 2023-02-17 23:42:16 +0000

    LinuxKPI: return an address string in pci_name()
    
    amdgpu's virtual display feature uses pci_name() to match a module parameter
    string, and the documentation shows an example of `0000:26:00.0` for the name.
    In our case the name was just `drmn`, which is not actually unique across
    devices.
    
    The other consumers are wireless drivers, which will benefit from this
    change.
    
    Generate the expected string for pci_name() to return.
    
    Related to:     https://github.com/freebsd/drm-kmod/issues/134
    Sponsored by:   https://www.patreon.com/valpackett
    Reviewed by:    bz, hselasky, manu (earlier)
    MFC after:      3 days
    Differential Revision: https://reviews.freebsd.org/D34248
    
    (cherry picked from commit 393b0ba25f1a54dcc3f94244933c665f1c471d1a)
---
 sys/compat/linuxkpi/common/include/linux/pci.h | 4 ++--
 sys/compat/linuxkpi/common/src/linux_pci.c     | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/sys/compat/linuxkpi/common/include/linux/pci.h b/sys/compat/linuxkpi/common/include/linux/pci.h
index 48bdabda9f21..f8071524c9e0 100644
--- a/sys/compat/linuxkpi/common/include/linux/pci.h
+++ b/sys/compat/linuxkpi/common/include/linux/pci.h
@@ -355,6 +355,7 @@ struct pci_dev {
 	bool			msix_enabled;
 	uint8_t			msi_cap;
 	struct msi_desc		**msi_desc;
+	char			*path_name;
 };
 
 /* XXX add kassert here on the mmio offset */
@@ -475,8 +476,7 @@ pci_resource_flags(struct pci_dev *pdev, int bar)
 static inline const char *
 pci_name(struct pci_dev *d)
 {
-
-	return device_get_desc(d->dev.bsddev);
+	return d->path_name;
 }
 
 static inline void *
diff --git a/sys/compat/linuxkpi/common/src/linux_pci.c b/sys/compat/linuxkpi/common/src/linux_pci.c
index 5f3a24210c03..88a6b749a043 100644
--- a/sys/compat/linuxkpi/common/src/linux_pci.c
+++ b/sys/compat/linuxkpi/common/src/linux_pci.c
@@ -309,6 +309,9 @@ lkpifill_pci_dev(device_t dev, struct pci_dev *pdev)
 	pdev->subsystem_device = pci_get_subdevice(dev);
 	pdev->class = pci_get_class(dev);
 	pdev->revision = pci_get_revid(dev);
+	pdev->path_name = kasprintf(GFP_KERNEL, "%04d:%02d:%02d.%d",
+	    pci_get_domain(dev), pci_get_bus(dev), pci_get_slot(dev),
+	    pci_get_function(dev));
 	pdev->bus = malloc(sizeof(*pdev->bus), M_DEVBUF, M_WAITOK | M_ZERO);
 	/*
 	 * This should be the upstream bridge; pci_upstream_bridge()
@@ -352,6 +355,7 @@ lkpinew_pci_dev_release(struct device *dev)
 			free(pdev->msi_desc[i], M_DEVBUF);
 		free(pdev->msi_desc, M_DEVBUF);
 	}
+	kfree(pdev->path_name);
 	free(pdev, M_DEVBUF);
 }