kernel/linux.git/drivers/ntb/hw/mscc, branch linux-4.16.y

ntb_hw_switchtec: Make function switchtec_ntb_remove() static

2018-01-29T03:17:24+00:00

Fixes the following sparse warnings: drivers/ntb/hw/mscc/ntb_hw_switchtec.c:1552:6: warning: symbol 'switchtec_ntb_remove' was not declared. Should it be static? Signed-off-by: Wei Yongjun Reviewed-by: Logan Gunthorpe Signed-off-by: Jon Mason

ntb_hw_switchtec: fix logic error

2018-01-29T03:17:23+00:00

Newer gcc (version 7 and 8 presumably) warn about a statement mixing the << operator with logical and: drivers/ntb/hw/mscc/ntb_hw_switchtec.c: In function 'switchtec_ntb_init_sndev': drivers/ntb/hw/mscc/ntb_hw_switchtec.c:888:24: error: '<<' in boolean context, did you mean '<' ? [-Werror=int-in-bool-context] My interpretation here is that the author must have intended a bitmask rather than a comparison, so I'm changing the '&&' to '&', which makes a lot more sense in the context. Fixes: 1b249475275d ("ntb_hw_switchtec: Allow using Switchtec NTB in multi-partition setups") Reviewed-by: Logan Gunthorpe Signed-off-by: Arnd Bergmann Signed-off-by: Jon Mason

ntb_hw_switchtec: Check for alignment of the buffer in mw_set_trans()

2018-01-29T03:17:23+00:00

With Switchtec hardware, the buffer used for a memory window must be aligned to its size (the hardware only replaces the lower bits). In certain circumstances dma_alloc_coherent() will not provide a buffer that adheres to this requirement like when using the CMA and CONFIG_CMA_ALIGNMENT is set lower than the buffer size. When we get an unaligned buffer mw_set_trans() should return an error. We also log an error so we know the cause of the problem. Signed-off-by: Logan Gunthorpe Signed-off-by: Jon Mason

ntb_hw_switchtec: Force down the link before initializing

2018-01-29T03:17:23+00:00

If one host crashes and soft reboots, the other host may not see a link down event. Then when the crashed host comes back up, the surviving host may not know the link was reset and the NTB clients may not work without being reset. To solve this, we send a LINK_FORCE_DOWN message to each peer every time we come up, before we register the NTB device. If a surviving host still thinks the link is up it will take it down immediately. In this way, once the crashed host comes up fully, it will send a regular link up event as per usual and the link will be properly restarted. While we are in the area, this also fixes the MSG_LINK_UP message that was in the link down function that was reported by Doug Meyers. Signed-off-by: Logan Gunthorpe Reported-by: ThanhTuThai Signed-off-by: Jon Mason

ntb_hw_switchtec: Crosslink doorbells and messages

2018-01-29T03:17:23+00:00

In a crosslink configuration doorbells and messages largely work the same but the NTB registers must be accessed through the reserved LUT window. Also, as a bonus, seeing there are now two independent sets of NTB links, both partitions can actually use all 60 doorbell registers instead of them having to be split into two for each partition. Signed-off-by: Logan Gunthorpe Signed-off-by: Jon Mason

ntb_hw_switchtec: Add initialization code for crosslink

2018-01-29T03:17:23+00:00

Crosslink is a feature of the Switchtec switches that is similar to the B2B mode of other NTB devices. It allows a system to be designed that is perfectly symmetric with two identical switches that link two hosts together. In order for the system to be symmetric, there is an empty host-less partition between the two switches which the host must enumerate and assign BAR addresses to. The firmware in the switch manages this specially so that the BAR addresses on both sides of the empty partition will be identical despite being in the same partition with the same address space. The driver determines whether crosslink is enabled by a flag set in the NTB partition info registers which are set by the switch's configuration file. When crosslink is enabled, a reserved LUT window is setup to point to the peer's switch's NTB registers and the local MWs are set to forward to the host-less partition's BARs. (Yes, this hurts my brain too.) Once this is setup, largely the same NTB infrastructure is used to communicate between the two hosts. Signed-off-by: Logan Gunthorpe Signed-off-by: Jon Mason

ntb_hw_switchtec: Make switchtec_ntb_init_req_id_table() more general

2018-01-29T03:17:23+00:00

This is a prep patch in order to support the crosslink feature which will require the driver to setup the requester ID table in another partition as well as it's own. To aid this, create a helper function which sets up the requester IDs from an array. Signed-off-by: Logan Gunthorpe Signed-off-by: Jon Mason

ntb_hw_switchtec: Create helper function to setup reserved LUT MWs

2018-01-29T03:17:23+00:00

This is a prep patch in order to support the crosslink feature which will require the driver to use another reserved LUT window. To simplify this we move the code which sets up the reserved LUT window into a helper function which will be used by the crosslink initialization. Signed-off-by: Logan Gunthorpe Signed-off-by: Jon Mason

ntb_hw_switchtec: Keep track of the number of LUT windows used by the driver

2018-01-29T03:17:23+00:00

This is a prep patch in order to support the crosslink feature which will require the driver to use another reserved LUT window. To simplify this, we add some code to track the number of reserved LUT windows in use instead of assuming this is always 1. Signed-off-by: Logan Gunthorpe Signed-off-by: Jon Mason

ntb_hw_switchtec: Allow using Switchtec NTB in multi-partition setups

2018-01-29T03:17:23+00:00

Allow using Switchtec NTB in setups that have more than two partitions. Note: this does not enable having multi-host communication, it only allows for a single NTB link between two hosts in a network that might have more than two. Use following logic to determine the NT peer partition: 1) If there are 2 partitions, and the target vector is set in the Switchtec configuration, use the partition specified in target vector. 2) If there are 2 partitions and target vector is unset use the only other partition as specified in the NT EP map. 3) If there are more than 2 partitions and target vector is set use the other partition specified in target vector. 4) If there are more than 2 partitions and target vector is unset, this is invalid and report an error. Signed-off-by: Kelvin Cao [logang@deltatee.com: commit message fleshed out] Signed-off-by: Logan Gunthorpe Reviewed-by: Logan Gunthorpe Signed-off-by: Jon Mason