| Message ID | 20190722230859.5436-7-logang@deltatee.com |
|---|---|
| State | Superseded |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI/P2PDMA: Support transactions that hit the host bridge | expand |
On Mon, Jul 22, 2019 at 05:08:51PM -0600, Logan Gunthorpe wrote: > Intel devices do not have good support for P2P requests that span > different host bridges as the transactions will cross the QPI/UPI bus > and this does not perform well. > > Therefore, enable support for these devices only if the host bridges > match. > > Adds the Intel device's that have been tested to work. There are > likely many others out there that will need to be tested and added. > > Signed-off-by: Logan Gunthorpe <logang@deltatee.com> > drivers/pci/p2pdma.c | 36 ++++++++++++++++++++++++++++++++---- > 1 file changed, 32 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c > index dfb802afc8ca..143e11d2a5c3 100644 > +++ b/drivers/pci/p2pdma.c > @@ -250,9 +250,28 @@ 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 __host_bridge_whitelist(struct pci_host_bridge *host) > +static const struct pci_p2pdma_whitelist_entry { > + unsigned short vendor; > + unsigned short device; > + bool req_same_host_bridge; This would be more readable in the initializer as a flags not a bool Jason
On 2019-07-25 12:52 p.m., Jason Gunthorpe wrote: > On Mon, Jul 22, 2019 at 05:08:51PM -0600, Logan Gunthorpe wrote: >> Intel devices do not have good support for P2P requests that span >> different host bridges as the transactions will cross the QPI/UPI bus >> and this does not perform well. >> >> Therefore, enable support for these devices only if the host bridges >> match. >> >> Adds the Intel device's that have been tested to work. There are >> likely many others out there that will need to be tested and added. >> >> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> >> drivers/pci/p2pdma.c | 36 ++++++++++++++++++++++++++++++++---- >> 1 file changed, 32 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c >> index dfb802afc8ca..143e11d2a5c3 100644 >> +++ b/drivers/pci/p2pdma.c >> @@ -250,9 +250,28 @@ 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 __host_bridge_whitelist(struct pci_host_bridge *host) >> +static const struct pci_p2pdma_whitelist_entry { >> + unsigned short vendor; >> + unsigned short device; >> + bool req_same_host_bridge; > > This would be more readable in the initializer as a flags not a bool Ok, will change for v2. Logan
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index dfb802afc8ca..143e11d2a5c3 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -250,9 +250,28 @@ 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 __host_bridge_whitelist(struct pci_host_bridge *host) +static const struct pci_p2pdma_whitelist_entry { + unsigned short vendor; + unsigned short device; + bool req_same_host_bridge; +} pci_p2pdma_whitelist[] = { + /* AMD ZEN */ + {PCI_VENDOR_ID_AMD, 0x1450, false}, + + /* Intel Xeon E5/Core i7 */ + {PCI_VENDOR_ID_INTEL, 0x3c00, true}, + {PCI_VENDOR_ID_INTEL, 0x3c01, true}, + /* Intel Xeon E7 v3/Xeon E5 v3/Core i7 */ + {PCI_VENDOR_ID_INTEL, 0x2f00, true}, + {PCI_VENDOR_ID_INTEL, 0x2f01, true}, + {} +}; + +static bool __host_bridge_whitelist(struct pci_host_bridge *host, + bool same_host_bridge) { struct pci_dev *root = pci_get_slot(host->bus, PCI_DEVFN(0, 0)); + const struct pci_p2pdma_whitelist_entry *entry; unsigned short vendor, device; if (!root) @@ -262,9 +281,14 @@ static bool __host_bridge_whitelist(struct pci_host_bridge *host) device = root->device; pci_dev_put(root); - /* AMD ZEN host bridges can do peer to peer */ - if (vendor == PCI_VENDOR_ID_AMD && device == 0x1450) + for (entry = pci_p2pdma_whitelist; entry->vendor; entry++) { + if (vendor != entry->vendor || device != entry->device) + continue; + if (entry->req_same_host_bridge && !same_host_bridge) + return false; + return true; + } return false; } @@ -281,7 +305,11 @@ static bool host_bridge_whitelist(struct pci_dev *a, struct pci_dev *b) if (iommu_present(a->dev.bus) || iommu_present(b->dev.bus)) return false; - if (__host_bridge_whitelist(host_a) && __host_bridge_whitelist(host_b)) + if (host_a == host_b) + return __host_bridge_whitelist(host_a, true); + + if (__host_bridge_whitelist(host_a, false) && + __host_bridge_whitelist(host_b, false)) return true; return false;
Intel devices do not have good support for P2P requests that span different host bridges as the transactions will cross the QPI/UPI bus and this does not perform well. Therefore, enable support for these devices only if the host bridges match. Adds the Intel device's that have been tested to work. There are likely many others out there that will need to be tested and added. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> --- drivers/pci/p2pdma.c | 36 ++++++++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-)