diff options
author | Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com> | 2022-02-10 19:40:09 +0100 |
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committer | Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com> | 2022-02-23 10:46:27 +0100 |
commit | 7146765b80919e3f134398ba433b36a56377e4c9 (patch) | |
tree | 87fd3ef8863b9660117179519faed514467aa535 /lib/igt_device.c | |
parent | a1842d465c83c732c3e3d67d41c0e29cbaf7682d (diff) |
lib/igt_device: Add support for accessing unbound VF PCI devices
The library provides igt_device_get_pci_device() function that allows to
get access to a PCI device from an open DRM device file descriptor. It
can be used on VF devices as long as a DRM driver is bound to them.
However, SR-IOV tests may want to exercise VF PCI devices created by a PF
without binding any DRM driver to them.
While keeping the API of igt_device_get_pci_device() untouched, extend API
of its underlying helper __igt_device_get_pci_device() with an extra
argument for specifying VF ID of the requested PCI device and expose this
function as public.
v2: refresh on top of IGT libpciaccess wrappers and drop previously added
but no longer needed error unwind path and recommendations for users
on calling pci_system_cleanup() after use (Chris),
- fix incorrect validation of snprintf() result and misaligned
formatting of igt_warn_on_f() arguments.
Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
[jkrzyszt: DOC fix and wording improvement]
Diffstat (limited to 'lib/igt_device.c')
-rw-r--r-- | lib/igt_device.c | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/lib/igt_device.c b/lib/igt_device.c index c50bf4a1..9794a992 100644 --- a/lib/igt_device.c +++ b/lib/igt_device.c @@ -149,9 +149,9 @@ struct igt_pci_addr { unsigned int function; }; -static int igt_device_get_pci_addr(int fd, struct igt_pci_addr *pci) +static int igt_device_get_pci_addr(int fd, unsigned int vf_id, struct igt_pci_addr *pci) { - char path[IGT_DEV_PATH_LEN]; + char link[20], path[IGT_DEV_PATH_LEN]; char *buf; int sysfs; int len; @@ -159,11 +159,21 @@ static int igt_device_get_pci_addr(int fd, struct igt_pci_addr *pci) if (!igt_device_is_pci(fd)) return -ENODEV; + if (vf_id) + len = snprintf(link, sizeof(link), "device/virtfn%u", vf_id - 1); + else + len = snprintf(link, sizeof(link), "device"); + if (igt_warn_on_f(len >= sizeof(link), + "IGT bug: insufficient buffer space for rendering PCI device link name\n")) + return -ENOSPC; + else if (igt_debug_on_f(len < 0, "unexpected failure from snprintf()\n")) + return len; + sysfs = igt_sysfs_open(fd); if (sysfs == -1) return -ENOENT; - len = readlinkat(sysfs, "device", path, sizeof(path) - 1); + len = readlinkat(sysfs, link, path, sizeof(path) - 1); close(sysfs); if (len == -1) return -ENOENT; @@ -183,12 +193,23 @@ static int igt_device_get_pci_addr(int fd, struct igt_pci_addr *pci) return 0; } -static struct pci_device *__igt_device_get_pci_device(int fd) +/** + * __igt_device_get_pci_device: + * + * @fd: DRM device file descriptor + * @vf_id: PCI virtual function number (0 if native or PF itself) + * + * Looks up a PCI interface of a DRM device or a VF PCI device of the DRM PF using libpciaccess. + * + * Returns: + * The pci_device, NULL on any failures. + */ +struct pci_device *__igt_device_get_pci_device(int fd, unsigned int vf_id) { struct igt_pci_addr pci_addr; struct pci_device *pci_dev; - if (igt_device_get_pci_addr(fd, &pci_addr)) { + if (igt_device_get_pci_addr(fd, vf_id, &pci_addr)) { igt_warn("Unable to find device PCI address\n"); return NULL; } @@ -231,7 +252,7 @@ struct pci_device *igt_device_get_pci_device(int fd) { struct pci_device *pci_dev; - pci_dev = __igt_device_get_pci_device(fd); + pci_dev = __igt_device_get_pci_device(fd, 0); igt_require(pci_dev); return pci_dev; |