linux-kernel - [PATCH v10 2/4] PCI/VGA: Replace vga_is_firmware

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Message-ID: <20250811162606.587759-3-superm1@kernel.org>
Date: Mon, 11 Aug 2025 11:26:04 -0500
From: "Mario Limonciello (AMD)" <superm1@...nel.org>
To: David Airlie <airlied@...il.com>,
	Bjorn Helgaas <bhelgaas@...gle.com>
Cc: Alex Deucher <alexander.deucher@....com>,
	Christian König <christian.koenig@....com>,
	Simona Vetter <simona@...ll.ch>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	dri-devel@...ts.freedesktop.org (open list:DRM DRIVERS),
	linux-kernel@...r.kernel.org (open list),
	linux-pci@...r.kernel.org (open list:PCI SUBSYSTEM),
	Daniel Dadap <ddadap@...dia.com>,
	"Mario Limonciello (AMD)" <superm1@...nel.org>
Subject: [PATCH v10 2/4] PCI/VGA: Replace vga_is_firmware_default() with a screen info check

vga_is_firmware_default() checks firmware resources to find the owner
framebuffer resources to find the firmware PCI device.  This is an
open coded implementation of screen_info_pci_dev().  Switch to using
screen_info_pci_dev() instead.

Acked-by: Bjorn Helgaas <bhelgaas@...gle.com>
Suggested-by: Thomas Zimmermann <tzimmermann@...e.de>
Signed-off-by: Mario Limonciello (AMD) <superm1@...nel.org>
---
v10:
 * Rebase on 6.17-rc1
---
 drivers/pci/vgaarb.c | 31 +++++--------------------------
 1 file changed, 5 insertions(+), 26 deletions(-)

diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
index 78748e8d2dbae..b58f94ee48916 100644
--- a/drivers/pci/vgaarb.c
+++ b/drivers/pci/vgaarb.c
@@ -556,34 +556,13 @@ EXPORT_SYMBOL(vga_put);
 
 static bool vga_is_firmware_default(struct pci_dev *pdev)
 {
-#if defined(CONFIG_X86)
-	u64 base = screen_info.lfb_base;
-	u64 size = screen_info.lfb_size;
-	struct resource *r;
-	u64 limit;
+#ifdef CONFIG_SCREEN_INFO
+	struct screen_info *si = &screen_info;
 
-	/* Select the device owning the boot framebuffer if there is one */
-
-	if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
-		base |= (u64)screen_info.ext_lfb_base << 32;
-
-	limit = base + size;
-
-	/* Does firmware framebuffer belong to us? */
-	pci_dev_for_each_resource(pdev, r) {
-		if (resource_type(r) != IORESOURCE_MEM)
-			continue;
-
-		if (!r->start || !r->end)
-			continue;
-
-		if (base < r->start || limit >= r->end)
-			continue;
-
-		return true;
-	}
-#endif
+	return pdev == screen_info_pci_dev(si);
+#else
 	return false;
+#endif
 }
 
 static bool vga_arb_integrated_gpu(struct device *dev)
-- 
2.43.0