kernel/linux.git/include/linux/ntb.h, branch v6.6.131

NTB: correct ntb_peer_spad_addr and ntb_peer_spad_read comment typos

2020-06-06T00:02:08+00:00

The comment for ntb_peer_spad_addr and ntb_peer_spad_read incorrectly referred to peer doorbell register and local scratchpad register. Signed-off-by: Wesley Sheng Signed-off-by: Jon Mason

include/ntb: Fix typo in ntb_unregister_device description

2020-04-13T14:28:34+00:00

Signed-off-by: Maciej Grochowski Signed-off-by: Jon Mason

NTB: Introduce MSI library

2019-06-13T13:02:33+00:00

The NTB MSI library allows passing MSI interrupts across a memory window. This offers similar functionality to doorbells or messages except will often have much better latency and the client can potentially use significantly more remote interrupts than typical hardware provides for doorbells. (Which can be important in high-multiport setups.) The library utilizes one memory window per peer and uses the highest index memory windows. Before any ntb_msi function may be used, the user must call ntb_msi_init(). It may then setup and tear down the memory windows when the link state changes using ntb_msi_setup_mws() and ntb_msi_clear_mws(). The peer which receives the interrupt must call ntb_msim_request_irq() to assign the interrupt handler (this function is functionally similar to devm_request_irq()) and the returned descriptor must be transferred to the peer which can use it to trigger the interrupt. The triggering peer, once having received the descriptor, can trigger the interrupt by calling ntb_msi_peer_trigger(). Signed-off-by: Logan Gunthorpe Cc: Dave Jiang Cc: Allen Hubbe Signed-off-by: Jon Mason

NTB: Introduce functions to calculate multi-port resource index

2019-06-13T12:59:58+00:00

When using multi-ports each port uses resources (dbs, msgs, mws, etc) on every other port. Creating a mapping for these resources such that each port has a corresponding resource on every other port is a bit tricky. Introduce the ntb_peer_resource_idx() function for this purpose. It returns the peer resource number that will correspond with the local peer index on the remote peer. Also, introduce ntb_peer_highest_mw_idx() which will use ntb_peer_resource_idx() but return the MW index starting with the highest index and working down. Signed-off-by: Logan Gunthorpe Cc: Dave Jiang Cc: Allen Hubbe Signed-off-by: Jon Mason

NTB: Introduce helper functions to calculate logical port number

2019-06-13T12:59:47+00:00

This patch introduces the "Logical Port Number" which is similar to the "Port Number" in that it enumerates the ports in the system. The original (or Physical) "Port Number" can be any number used by the hardware to uniquely identify a port in the system. The "Logical Port Number" enumerates all ports in the system from 0 to the number of ports minus one. For example a system with 5 ports might have the following port numbers which would be enumerated thusly: Port Number: 1 2 5 7 116 Logical Port Number: 0 1 2 3 4 The logical port number is useful when calculating which resources to use for which peers. So we thus define two helper functions: ntb_logical_port_number() and ntb_peer_logical_port_number() which provide the "Logical Port Number" for the local port and any peer respectively. Signed-off-by: Logan Gunthorpe Cc: Dave Jiang Cc: Allen Hubbe Cc: Serge Semin Signed-off-by: Jon Mason

NTB: correct ntb_dev_ops and ntb_dev comment typos

2019-06-13T12:59:22+00:00

The comment for ntb_dev_ops and ntb_dev incorrectly referred to ntb_ctx_ops and ntb_device. Signed-off-by: Wesley Sheng Reviewed-by: Logan Gunthorpe Signed-off-by: Jon Mason

NTB: add new parameter to peer_db_addr() db_bit and db_data

2019-02-13T16:03:18+00:00

NTB door bell usage depends on NTB hardware. ex: intel NTB gen1 has one peer door bell register which can be controlled by the bitmap writen to it, while Intel NTB gen3 has a registers per door bell and the data trigering the each door bell is always 1. therefore exposing only peer door bell address forcing the user to be aware of such low level details Signed-off-by: Leonid Ravich Acked-by: Logan Gunthorpe Acked-by: Dave Jiang Acked-by: Allen Hubbe Signed-off-by: Jon Mason

NTB: Fix UB/bug in ntb_mw_get_align()

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

Simple (1 << pidx) operation causes undefined behaviour when pidx >= 32. It must be casted to u64 to match the actual return value of ntb_link_is_up() method, so to have all the possible peer indexes covered and to get rid of undefined behaviour. Additionally there are special macros in "linux/bitops.h" to perform the bit-set-shift operations, so it's recommended to have them used for proper bit setting. Signed-off-by: Serge Semin Reviewed-by: Logan Gunthorpe Signed-off-by: Jon Mason

NTB: Rename NTB messaging API methods

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

There is a common methods signature form used over all the NTB API like functions naming scheme, arguments names and order, etc. Recently added NTB messaging API IO callbacks were named a bit different so should be renamed to be in compliance with the rest of the API. Signed-off-by: Serge Semin 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