From: Jacob Moroni <jmoroni@google.com>
Date: Thu, 9 Apr 2026 15:01:22 +0000 (+0000)
Subject: PCI/P2PDMA: Allow wildcard Device IDs in host bridge list
X-Git-Tag: v7.1-rc1~151^2~27^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1a1f96e3e2a8dc1774c626bc6e15944c3e160393;p=thirdparty%2Fkernel%2Fstable.git

PCI/P2PDMA: Allow wildcard Device IDs in host bridge list

Currently, the pci_p2pdma_whitelist array requires an exact match for both
Vendor and Device ID. Some hardware vendors support cross bridge
peer-to-peer DMA across their entire silicon lineup, so add support for
wildcard device IDs to avoid the need to continuously update this array.

Signed-off-by: Jacob Moroni <jmoroni@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Link: https://patch.msgid.link/20260409150123.3538444-1-jmoroni@google.com
---

diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index e0f546166eb86..25e9358d066e0 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -530,7 +530,7 @@ static bool cpu_supports_p2pdma(void)
 
 static const struct pci_p2pdma_whitelist_entry {
 	unsigned short vendor;
-	unsigned short device;
+	int device;
 	enum {
 		REQ_SAME_HOST_BRIDGE	= 1 << 0,
 	} flags;
@@ -601,8 +601,12 @@ static bool __host_bridge_whitelist(struct pci_host_bridge *host,
 	device = root->device;
 
 	for (entry = pci_p2pdma_whitelist; entry->vendor; entry++) {
-		if (vendor != entry->vendor || device != entry->device)
+		if (vendor != entry->vendor)
 			continue;
+
+		if (entry->device != PCI_ANY_ID && device != entry->device)
+			continue;
+
 		if (entry->flags & REQ_SAME_HOST_BRIDGE && !same_host_bridge)
 			return false;