[PATCH 03/11] drm/xe: Cap MSI-X vector count to XE_MSIX_MAX_VECS

[Stuart Summers <stuart.summers@intel.com>]

Introduce XE_MSIX_MAX_VECS (1024) as a software cap on the total number
of MSI-X vectors the driver will use. We want a way to cap the number
of vectors separately from the PCIe capability. This way we can more
easily manage certain system-wide configurations that might differ
from the per-device level configuration.

Signed-off-by: Stuart Summers <stuart.summers@intel.com>
Assisted-by: Copilot:claude-sonnet-4.6
---
 drivers/gpu/drm/xe/xe_irq.c | 2 +-
 drivers/gpu/drm/xe/xe_irq.h | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_irq.c b/drivers/gpu/drm/xe/xe_irq.c
index 9e49e2241da4..3429bb305293 100644
--- a/drivers/gpu/drm/xe/xe_irq.c
+++ b/drivers/gpu/drm/xe/xe_irq.c
@@ -895,7 +895,7 @@ static int xe_irq_msix_init(struct xe_device *xe)
 		return nvec;
 	}
 
-	xe->irq.msix.nvec = nvec;
+	xe->irq.msix.nvec = min_t(int, nvec, XE_MSIX_MAX_VECS);
 	xa_init_flags(&xe->irq.msix.indexes, XA_FLAGS_ALLOC);
 	return 0;
 }
diff --git a/drivers/gpu/drm/xe/xe_irq.h b/drivers/gpu/drm/xe/xe_irq.h
index a28bd577ba52..5f48249dae8a 100644
--- a/drivers/gpu/drm/xe/xe_irq.h
+++ b/drivers/gpu/drm/xe/xe_irq.h
@@ -10,6 +10,13 @@
 
 #define XE_IRQ_DEFAULT_MSIX 1
 
+/*
+ * Software cap on the total number of MSI-X vectors the driver will use.
+ * Allows the supported vectors to be managed independent of the PCI
+ * config space report.
+ */
+#define XE_MSIX_MAX_VECS 1024
+
 struct xe_device;
 struct xe_tile;
 struct xe_gt;
-- 
2.43.0