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authorLogan Gunthorpe <logang@deltatee.com>2020-07-29 17:18:44 -0600
committerBjorn Helgaas <bhelgaas@google.com>2020-07-30 10:18:17 -0500
commitdea286bb71baded7d2fb4f090e3b9fd2c1ccac58 (patch)
tree0603dfe6773b967143297a33949b73d40e897868 /drivers/pci/p2pdma.c
parentb3a9e3b9622ae10064826dccb4f7a52bd88c7407 (diff)
downloadlinux-dea286bb71baded7d2fb4f090e3b9fd2c1ccac58.tar.gz
PCI/P2PDMA: Allow P2PDMA on AMD Zen and newer CPUs
Allow P2PDMA if the CPU vendor is AMD and family is 0x17 (Zen) or greater.

[bhelgaas: commit log, simplify #if/#else/#endif]
Link: https://lore.kernel.org/r/20200729231844.4653-1-logang@deltatee.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Diffstat (limited to 'drivers/pci/p2pdma.c')
-rw-r--r--drivers/pci/p2pdma.c21
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index e8e444eeb1cd..1ec61fced4c3 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -273,6 +273,19 @@ static void seq_buf_print_bus_devfn(struct seq_buf *buf, struct pci_dev *pdev)
 	seq_buf_printf(buf, "%s;", pci_name(pdev));
 }
 
+static bool cpu_supports_p2pdma(void)
+{
+#ifdef CONFIG_X86
+	struct cpuinfo_x86 *c = &cpu_data(0);
+
+	/* Any AMD CPU whose family ID is Zen or newer supports p2pdma */
+	if (c->x86_vendor == X86_VENDOR_AMD && c->x86 >= 0x17)
+		return true;
+#endif
+
+	return false;
+}
+
 static const struct pci_p2pdma_whitelist_entry {
 	unsigned short vendor;
 	unsigned short device;
@@ -280,11 +293,6 @@ static const struct pci_p2pdma_whitelist_entry {
 		REQ_SAME_HOST_BRIDGE	= 1 << 0,
 	} flags;
 } pci_p2pdma_whitelist[] = {
-	/* AMD ZEN */
-	{PCI_VENDOR_ID_AMD,	0x1450,	0},
-	{PCI_VENDOR_ID_AMD,	0x15d0,	0},
-	{PCI_VENDOR_ID_AMD,	0x1630,	0},
-
 	/* Intel Xeon E5/Core i7 */
 	{PCI_VENDOR_ID_INTEL,	0x3c00, REQ_SAME_HOST_BRIDGE},
 	{PCI_VENDOR_ID_INTEL,	0x3c01, REQ_SAME_HOST_BRIDGE},
@@ -473,7 +481,8 @@ upstream_bridge_distance(struct pci_dev *provider, struct pci_dev *client,
 					      acs_redirects, acs_list);
 
 	if (map_type == PCI_P2PDMA_MAP_THRU_HOST_BRIDGE) {
-		if (!host_bridge_whitelist(provider, client))
+		if (!cpu_supports_p2pdma() &&
+		    !host_bridge_whitelist(provider, client))
 			map_type = PCI_P2PDMA_MAP_NOT_SUPPORTED;
 	}