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path: root/drivers/ntb
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2015-11-08NTB: unify translation addressesDave Jiang
There is no need for the upstream and downstream addresses to be different for the NTB configs. Go to using a single set of address. It is still possible to configure them differently using module parameter override however. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Acked and Tested-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-11-08NTB: invalid buf pointer in multi-MW setupsJon Mason
Order of operations issue with the QP Num and MW count, which would result in the receive buffer pointer being invalid if there are more than 1 MW. Corrected with parenthesis to enforce the proper order of operations. Reported-by: John I. Kading <John.Kading@gd-ms.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-11-08NTB: remove unused variableSudip Mukherjee
These variables were not used anywhere. So remove them. Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-11-08NTB: fix access of free-ed pointerSudip Mukherjee
We were accessing nt->mw_vec after freeing it. Fix the error path so that we free nt->mw_vec after we have finished using it. Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-11-08NTB: Fix issue where we may be accessing NULL ptrDave Jiang
smatch detected an issue in the function ntb_transport_max_size() where we could be dereferencing a dma channel pointer when it is NULL. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07NTB: Fix range check on memory window indexAllen Hubbe
The range check must exclude the upper bound. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07NTB: Improve index handling in B2B MW workaroundAllen Hubbe
Check that b2b_mw_idx is in range of the number of memory windows when initializing the device. The workaround is considered to be in effect only if the device b2b_idx is exactly UINT_MAX, instead of any index past the last memory window. Only print B2B MW workaround information in debugfs if the workaround is in effect. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07NTB: Use unique DMA channels for TX and RXDave Jiang
Allocate two DMA channels, one for TX operation and one for RX operation, instead of having one DMA channel for everything. This provides slightly better performance, and also will make error handling cleaner later on. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07NTB: Remove dma_sync_wait from ntb_async_rxAllen Hubbe
The dma_sync_wait can hurt the performance of workloads mixed with both large and small frames. Large frames will be copied using the dma engine. Small frames will be copied by the cpu. The dma_sync_wait prevents the cpu and dma engine copying in parallel. In the period where the cpu is copying, the dma engine is stopped. The dma engine is not doing any useful work to copy large frames during that time, and the additional time to restart the dma engine for the next large frame. This will decrease the throughput for the portion of a workload with large frames. In the period where the dma engine is copying, the cpu is held up waiting for dma to complete. The small frames processing will be delayed until the dma is complete. The RX frames are completed in-order, and the processing of small frames takes very little time, so dma_sync_wait may have an insignificant impact on the respose time of frames. The more significant impact is to the system, because the delay in dma_sync_wait is implemented as busy non-blocking wait. This can prevent the delayed core from doing any useful work, even if it could be processing work for other drivers, unrelated to transport RX processing. After applying the earlier patch to fix out-of-order RX acknoledgement, the dma_sync_wait is no longer necessary. Remove it, so that cpu memcpy will proceed immediately for small frames, in parallel with ongoing dma for large frames. Do not hold up the cpu from doing work while dma is in progress. The prior fix will continue to ensure in-order completion of the RX frames to the upper layer, and in-order delivery of the RX acknoledgement. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07NTB: Clean up QP stats infoDave Jiang
Make QP stats info more readable for debugging purposes. Also add an entry to indicate whether DMA is being used. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07NTB: Make the transport list in order of discoveryDave Jiang
The list should be added from the bottom and not the top in order to ensure the transport is provided in the same order to clients as ntb devices are discovered. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07NTB: Add PCI Device IDs for Broadwell XeonDave Jiang
Adding PCI Device IDs for B2B (back to back), RP (root port, primary), and TB (transparent bridge, secondary) devices. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07NTB: Add flow control to the ntb_netdevDave Jiang
Right now if we push the NTB really hard, we start dropping packets due to not able to process the packets fast enough. We need to st:qop the upper layer from flooding us when that happens. A timer is necessary in order to restart the queue once the resource has been processed on the receive side. Due to the way NTB is setup, the resources on the tx side are tied to the processing of the rx side and there's no async way to know when the rx side has released those resources. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09ntb: avoid format string in dev_set_nameKees Cook
Avoid any chance of format string expansion when calling dev_set_name. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09NTB: Fix dereference before checkAllen Hubbe
Remove early dereference of a pointer that is checked later in the code. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09NTB: Fix zero size or integer overflow in ntb_set_mwAllen Hubbe
A plain 32 bit integer will overflow for values over 4GiB. Change the plain integer size to the appropriate size type in ntb_set_mw. Change the type of the size parameter and two local variables used for size. Even if there is no overflow, a size of zero is invalid here. Reported-by: Juyoung Jung <jjung@micron.com> Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09NTB: Schedule to receive on QP link upAllen Hubbe
Schedule to receive on QP link up, to make sure that the doorbell is properly cleared for interrupts. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09NTB: Fix oops in debugfs when transport is half-upDave Jiang
When the remote side is not up, we do not have all the context for the transport, and that causes NULL ptr access. Have the debugfs reads check to see if transport is up before we make access. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09NTB: Fix transport stats for multiple devicesDave Jiang
Currently the debugfs does not have files for all NTB transport queue pairs. When there are multiple NTBs present in a system, the QP names of the last transport clobber the names of previously added transport QPs. Only the last added QPs can be observed via debugfs. Create a directory per NTB transport to associate the QPs with that transport. Name the directory the same as the PCI device. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09NTB: Fix ntb_transport out-of-order RX updateAllen Hubbe
It was possible for a synchronous update of the RX index in the error case to get ahead of the asynchronous RX index update in the normal case. Change the RX processing to preserve an RX completion order. There were two error cases. First, if a buffer is not present to receive data, there would be no queue entry to preserve the RX completion order. Instead of dropping the RX frame, leave the RX frame in the ring. Schedule RX processing when RX entries are enqueued, in case there are RX frames waiting in the ring to be received. Second, if a buffer is too small to receive data, drop the frame in the ring, mark the RX entry as done, and indicate the error in the RX entry length. Check for a negative length in the receive callback in ntb_netdev, and count occurrences as rx_length_errors. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Add split BAR output for debugfs statsDave Jiang
When split BAR is enabled, the driver needs to dump out the split BAR registers rather than the original 64bit BAR registers. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Change WARN_ON_ONCE to pr_warn_once on unsafeDave Jiang
The unsafe doorbell and scratchpad access should display reason when WARN is called. Otherwise we get a stack dump without any explanation. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Print driver name and version in module initDave Jiang
Printouts driver name and version to indicate what is being loaded. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Increase transport MTU to 64k from 16kDave Jiang
Benchmarking showed a significant performance increase with the MTU size to 64k instead of 16k. Change the driver default to 64k. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Rename Intel code names to platform namesDave Jiang
Instead of using the platform code names, use the correct platform names to identify the respective Intel NTB hardware. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Default to CPU memcpy for performanceDave Jiang
Disable DMA usage by default, since the CPU provides much better performance with write combining. Provide a module parameter to enable DMA usage when offloading the memcpy is preferred. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Improve performance with write combiningDave Jiang
Changing the memory window BAR mappings to write combining significantly boosts the performance. We will also use memcpy that uses non-temporal store, which showed performance improvement when doing non-cached memcpys. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Use NUMA memory in Intel driverAllen Hubbe
Allocate memory for the NUMA node of the NTB device. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Use NUMA memory and DMA chan in transportAllen Hubbe
Allocate memory and request the DMA channel for the same NUMA node as the NTB device. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Rate limit ntb_qp_link_workAllen Hubbe
When the ntb transport is connecting and waiting for the peer, the debug console receives lots of debug level messages about the remote qp link status being down. Rate limit those messages. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Add tool test clientAllen Hubbe
This is a simple debugging driver that enables the doorbell and scratch pad registers to be read and written from the debugfs. This tool enables more complicated debugging to be scripted from user space. This driver may be used to test that your ntb hardware and drivers are functioning at a basic level. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Add ping pong test clientAllen Hubbe
This is a simple ping pong driver that exercises the scratch pads and doorbells of the ntb hardware. This driver may be used to test that your ntb hardware and drivers are functioning at a basic level. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Add parameters for Intel SNB B2B addressesAllen Hubbe
Add module parameters for the addresses to be used in B2B topology. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Reset transport QP link stats on downAllen Hubbe
Reset the link stats when the link goes down. In particular, the TX and RX index and count must be reset, or else the TX side will be sending packets to the RX side where the RX side is not expecting them. Reset all the stats, to be consistent. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Do not advance transport RX on link downAllen Hubbe
On link down, don't advance RX index to the next entry. The next entry should never be valid after receiving the link down flag. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Differentiate transport link down messagesAllen Hubbe
The same message "qp %d: Link Down\n" was printed at two locations in ntb_transport. Change the messages so they are distinct. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Check the device ID to set errata flagsDave Jiang
Set errata flags for the specific device IDs to which they apply, instead of the whole Xeon hardware class. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Enable link for Intel root port mode in probeDave Jiang
Link training should be enabled in the driver probe for root port mode. We should not have to wait for transport to be loaded for this to happen. Otherwise the ntb device will not show up on the transparent bridge side of the link. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Read peer info from local SPAD in transportDave Jiang
The transport was writing and then reading the peer scratch pad, essentially reading what it just wrote instead of exchanging any information with the peer. The transport expects the peer values to be the same as the local values, so this issue was not obvious. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Split ntb_hw_intel and ntb_transport driversAllen Hubbe
Change ntb_hw_intel to use the new NTB hardware abstraction layer. Split ntb_transport into its own driver. Change it to use the new NTB hardware abstraction layer. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04NTB: Add NTB hardware abstraction layerAllen Hubbe
Abstract the NTB device behind a programming interface, so that it can support different hardware and client drivers. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-02NTB: Move files in preparation for NTB abstractionAllen Hubbe
This patch only moves files to their new locations, before applying the next two patches adding the NTB Abstraction layer. Splitting this patch from the next is intended make distinct which code is changed only due to moving the files, versus which are substantial code changes in adding the NTB Abstraction layer. Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-06-23Merge tag 'pci-v4.2-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "PCI changes for the v4.2 merge window: Enumeration - Move pci_ari_enabled() to global header (Alex Williamson) - Account for ARI in _PRT lookups (Alex Williamson) - Remove unused pci_scan_bus_parented() (Yijing Wang) Resource management - Use host bridge _CRS info on systems with >32 bit addressing (Bjorn Helgaas) - Use host bridge _CRS info on Foxconn K8M890-8237A (Bjorn Helgaas) - Fix pci_address_to_pio() conversion of CPU address to I/O port (Zhichang Yuan) - Add pci_bus_addr_t (Yinghai Lu) PCI device hotplug - Wait for pciehp command completion where necessary (Alex Williamson) - Drop pointless ACPI-based "slot detection" check (Rafael J. Wysocki) - Check ignore_hotplug for all downstream devices (Rafael J. Wysocki) - Propagate the "ignore hotplug" setting to parent (Rafael J. Wysocki) - Inline pciehp "handle event" functions into the ISR (Bjorn Helgaas) - Clean up pciehp debug logging (Bjorn Helgaas) Power management - Remove redundant PCIe port type checking (Yijing Wang) - Add dev->has_secondary_link to track downstream PCIe links (Yijing Wang) - Use dev->has_secondary_link to find downstream links for ASPM (Yijing Wang) - Drop __pci_disable_link_state() useless "force" parameter (Bjorn Helgaas) - Simplify Clock Power Management setting (Bjorn Helgaas) Virtualization - Add ACS quirks for Intel 9-series PCH root ports (Alex Williamson) - Add function 1 DMA alias quirk for Marvell 9120 (Sakari Ailus) MSI - Disable MSI at enumeration even if kernel doesn't support MSI (Michael S. Tsirkin) - Remove unused pci_msi_off() (Bjorn Helgaas) - Rename msi_set_enable(), msix_clear_and_set_ctrl() (Michael S. Tsirkin) - Export pci_msi_set_enable(), pci_msix_clear_and_set_ctrl() (Michael S. Tsirkin) - Drop pci_msi_off() calls during probe (Michael S. Tsirkin) APM X-Gene host bridge driver - Add APM X-Gene v1 PCIe MSI/MSIX termination driver (Duc Dang) - Add APM X-Gene PCIe MSI DTS nodes (Duc Dang) - Disable Configuration Request Retry Status for v1 silicon (Duc Dang) - Allow config access to Root Port even when link is down (Duc Dang) Broadcom iProc host bridge driver - Allow override of device tree IRQ mapping function (Hauke Mehrtens) - Add BCMA PCIe driver (Hauke Mehrtens) - Directly add PCI resources (Hauke Mehrtens) - Free resource list after registration (Hauke Mehrtens) Freescale i.MX6 host bridge driver - Add speed change timeout message (Troy Kisky) - Rename imx6_pcie_start_link() to imx6_pcie_establish_link() (Bjorn Helgaas) Freescale Layerscape host bridge driver - Use dw_pcie_link_up() consistently (Bjorn Helgaas) - Factor out ls_pcie_establish_link() (Bjorn Helgaas) Marvell MVEBU host bridge driver - Remove mvebu_pcie_scan_bus() (Yijing Wang) NVIDIA Tegra host bridge driver - Remove tegra_pcie_scan_bus() (Yijing Wang) Synopsys DesignWare host bridge driver - Consolidate outbound iATU programming functions (Jisheng Zhang) - Use iATU0 for cfg and IO, iATU1 for MEM (Jisheng Zhang) - Add support for x8 links (Zhou Wang) - Wait for link to come up with consistent style (Bjorn Helgaas) - Use pci_scan_root_bus() for simplicity (Yijing Wang) TI DRA7xx host bridge driver - Use dw_pcie_link_up() consistently (Bjorn Helgaas) Miscellaneous - Include <linux/pci.h>, not <asm/pci.h> (Bjorn Helgaas) - Remove unnecessary #includes of <asm/pci.h> (Bjorn Helgaas) - Remove unused pcibios_select_root() (again) (Bjorn Helgaas) - Remove unused pci_dma_burst_advice() (Bjorn Helgaas) - xen/pcifront: Don't use deprecated function pci_scan_bus_parented() (Arnd Bergmann)" * tag 'pci-v4.2-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (58 commits) PCI: pciehp: Inline the "handle event" functions into the ISR PCI: pciehp: Rename queue_interrupt_event() to pciehp_queue_interrupt_event() PCI: pciehp: Make queue_interrupt_event() void PCI: xgene: Allow config access to Root Port even when link is down PCI: xgene: Disable Configuration Request Retry Status for v1 silicon PCI: pciehp: Clean up debug logging x86/PCI: Use host bridge _CRS info on systems with >32 bit addressing PCI: imx6: Add #define PCIE_RC_LCSR PCI: imx6: Use "u32", not "uint32_t" PCI: Remove unused pci_scan_bus_parented() xen/pcifront: Don't use deprecated function pci_scan_bus_parented() PCI: imx6: Add speed change timeout message PCI/ASPM: Simplify Clock Power Management setting PCI: designware: Wait for link to come up with consistent style PCI: layerscape: Factor out ls_pcie_establish_link() PCI: layerscape: Use dw_pcie_link_up() consistently PCI: dra7xx: Use dw_pcie_link_up() consistently x86/PCI: Use host bridge _CRS info on Foxconn K8M890-8237A PCI: pciehp: Wait for hotplug command completion where necessary PCI: Remove unused pci_dma_burst_advice() ...
2015-06-11ntb: initialize max_mw for Atom before using itDaniel Verkamp
Commit ab760a0 (ntb: Adding split BAR support for Haswell platforms) changed ntb_device's mw from a fixed-size array into a pointer that is allocated based on limits.max_mw; however, on Atom platforms, max_mw is not initialized until ntb_device_setup(), which happens after the allocation. Fill out max_mw in ntb_atom_detect() to match ntb_xeon_detect(); this happens before the use of max_mw in the ndev->mw allocation. Fixes a null pointer dereference on Atom platforms with ntb hardware. v2: fix typo (mw_max should be max_mw) Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com> Acked-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-06-08ntb: iounmap MW reg and vbase in error pathJon Mason
The MW regbase and vbase(s) were not being freed if an error occurred in the vbase allocation loop. This is corrected by updating the error path for the allocation loop to err4. Reported-by: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-05-07ntb: Drop pci_msi_off() call during probeMichael S. Tsirkin
The PCI core now disables MSI and MSI-X for all devices during enumeration regardless of CONFIG_PCI_MSI. Remove device-specific code to disable MSI/MSI-X. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-10-17ntb: Adding split BAR support for Haswell platformsDave Jiang
On the Haswell platform, a split BAR option to allow creation of 2 32bit BARs (4 and 5) from the 64bit BAR 4. Adding support for this new option. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2014-10-17ntb: use errata flag set via DID to implement workaroundDave Jiang
Instead of using a module parameter, we should detect the errata via PCI DID and then set an appropriate flag. This will be used for additional errata later on. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2014-10-17ntb: conslidate reading of PPD to move platform detection earlierDave Jiang
To simplify some of the platform detection code. Move the platform detection to a function to be called earlier. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>
2014-10-17ntb: move platform detection to separate functionDave Jiang
Move the platform detection function to separate functions to allow easier maintenence. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Jon Mason <jdmason@kudzu.us>