From dea286bb71baded7d2fb4f090e3b9fd2c1ccac58 Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Wed, 29 Jul 2020 17:18:44 -0600 Subject: [PATCH] PCI/P2PDMA: Allow P2PDMA on AMD Zen and newer CPUs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Bjorn Helgaas Reviewed-by: Alex Deucher Cc: Christian König Cc: Huang Rui --- drivers/pci/p2pdma.c | 21 +++++++++++++++------ 1 file 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; }