PCI: Add pci_irq_type() to query the allocated interrupt typegrafted

Add a helper that returns PCI_IRQ_MSIX, PCI_IRQ_MSI, or PCI_IRQ_INTX
based on the interrupt type the PCI core selected after
pci_alloc_irq_vectors().

Several drivers already open-code this check against pdev->msix_enabled
and pdev->msi_enabled, or even open code this helper [1].

A common helper avoids the duplication and keeps drivers from accessing
the bitfield directly (see also [2]).

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Link: https://elixir.bootlin.com/linux/v7.1/source/drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c#L196 [1]
Inspired-by: John Hubbard <jhubbard@nvidia.com>
Link: https://lore.kernel.org/all/DKKG2QM3YJYB.Z2H2B2UXJ75N@kernel.org/ [2]
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260813165234.620555-5-dakr@kernel.org
[ Add missing pci_irq_type() stub for CONFIG_PCI=n. ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

1 files changed, 49 insertions, 0 deletions

diff --git a/Documentation/gpu/panfrost.rst b/Documentation/gpu/panfrost.rst
new file mode 100644
index 000000000..51ba375fd
--- /dev/null
+++ b/Documentation/gpu/panfrost.rst
@@ -0,0 +1,49 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+=========================
+ drm/Panfrost Mali Driver
+=========================
+
+.. _panfrost-usage-stats:
+
+Panfrost DRM client usage stats implementation
+==============================================
+
+The drm/Panfrost driver implements the DRM client usage stats specification as
+documented in :ref:`drm-client-usage-stats`.
+
+Example of the output showing the implemented key value pairs and entirety of
+the currently possible format options:
+
+::
+      pos:    0
+      flags:  02400002
+      mnt_id: 27
+      ino:    531
+      drm-driver:     panfrost
+      drm-client-id:  14
+      drm-engine-fragment:    1846584880 ns
+      drm-cycles-fragment:    1424359409
+      drm-maxfreq-fragment:   799999987 Hz
+      drm-curfreq-fragment:   799999987 Hz
+      drm-engine-vertex-tiler:        71932239 ns
+      drm-cycles-vertex-tiler:        52617357
+      drm-maxfreq-vertex-tiler:       799999987 Hz
+      drm-curfreq-vertex-tiler:       799999987 Hz
+      drm-total-memory:       290 MiB
+      drm-shared-memory:      0 MiB
+      drm-active-memory:      226 MiB
+      drm-resident-memory:    36496 KiB
+      drm-purgeable-memory:   128 KiB
+
+Possible `drm-engine-` key names are: `fragment`, and  `vertex-tiler`.
+`drm-curfreq-` values convey the current operating frequency for that engine.
+
+Users must bear in mind that engine and cycle sampling are disabled by default,
+because of power saving concerns. `fdinfo` users and benchmark applications which
+query the fdinfo file must make sure to toggle the job profiling status of the
+driver by writing into the appropriate sysfs node::
+
+    echo <N> > /sys/bus/platform/drivers/panfrost/[a-f0-9]*.gpu/profiling
+
+Where `N` is either `0` or `1`, depending on the desired enablement status.