Commit dea286bb authored by Logan Gunthorpe's avatar Logan Gunthorpe Committed by Bjorn Helgaas
Browse files

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: default avatarLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
parent b3a9e3b9

drivers/pci/p2pdma.c

+15 −6
Original line number Diff line number Diff line
@@ -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;

	}