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Merge branch 'pci/peer-to-peer'

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- Allow P2PDMA on AMD Zen and newer CPUs (Logan Gunthorpe)

* pci/peer-to-peer:
  PCI/P2PDMA: Allow P2PDMA on AMD Zen and newer CPUs
This commit is contained in:
Bjorn Helgaas 2020-08-05 18:24:17 -05:00
commit 4f7adb6ee7
1 changed files with 15 additions and 6 deletions
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21
drivers/pci/p2pdma.c
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@ -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;
}