git: 3166cea63244 - stable/13 - LinuxKPI: allow a driver to override the default pci probe result

From: Bjoern A. Zeeb <bz_at_FreeBSD.org>
Date: Sun, 27 Mar 2022 20:13:57 UTC
The branch stable/13 has been updated by bz:

URL: https://cgit.FreeBSD.org/src/commit/?id=3166cea632449ce6c6dad699a812b9813a9531ef

commit 3166cea632449ce6c6dad699a812b9813a9531ef
Author:     Bjoern A. Zeeb <bz@FreeBSD.org>
AuthorDate: 2022-02-18 21:58:01 +0000
Commit:     Bjoern A. Zeeb <bz@FreeBSD.org>
CommitDate: 2022-03-27 18:06:33 +0000

    LinuxKPI: allow a driver to override the default pci probe result
    
    Add bsd_probe_return which a driver can set in their 'struct pci_driver'
    definition to set a driver-sepcific LinuxKPI pci return value.
    This is helpful in case of multiple drivers with overlapping IDs,
    such as iwlwifi(4) and iwm(4).
    
    Contrary to an earlier version we now assume 0 is not BUS_PROBE_SPECIFIC
    (which no driver should really return these days) but the bss initialized
    value (bsd_probe_return unset) and we will return BUS_PROBE_DEFAULT.
    
    Suggested by:   jhb
    Reviewed by:    jhb
    Reviewed by:    hselasky, imp (earlier versions)
    Sponsored by:   The FreeBSD Foundation
    Differential Revision:  https://reviews.freebsd.org/D33915
    
    (cherry picked from commit b91dd79ba32122e6adb28073c534224bc78a7b58)
---
 sys/compat/linuxkpi/common/include/linux/pci.h | 1 +
 sys/compat/linuxkpi/common/src/linux_pci.c     | 7 ++++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/sys/compat/linuxkpi/common/include/linux/pci.h b/sys/compat/linuxkpi/common/include/linux/pci.h
index f463f697b5f7..df18c98a6278 100644
--- a/sys/compat/linuxkpi/common/include/linux/pci.h
+++ b/sys/compat/linuxkpi/common/include/linux/pci.h
@@ -215,6 +215,7 @@ struct pci_driver {
 	void  (*bsd_iov_uninit)(device_t dev);
 	int  (*bsd_iov_add_vf)(device_t dev, uint16_t vfnum,
 	    const nvlist_t *vf_config);
+	int				bsd_probe_return;
 };
 
 struct pci_bus {
diff --git a/sys/compat/linuxkpi/common/src/linux_pci.c b/sys/compat/linuxkpi/common/src/linux_pci.c
index 06feb5107ea5..ccb52732391e 100644
--- a/sys/compat/linuxkpi/common/src/linux_pci.c
+++ b/sys/compat/linuxkpi/common/src/linux_pci.c
@@ -361,7 +361,12 @@ linux_pci_probe(device_t dev)
 	if (device_get_driver(dev) != &pdrv->bsddriver)
 		return (ENXIO);
 	device_set_desc(dev, pdrv->name);
-	return (BUS_PROBE_DEFAULT);
+
+	/* Assume BSS initialized (should never return BUS_PROBE_SPECIFIC). */
+	if (pdrv->bsd_probe_return == 0)
+		return (BUS_PROBE_DEFAULT);
+	else
+		return (pdrv->bsd_probe_return);
 }
 
 static int