MFC r303429, r303437, r303551:

Once more refactor KPI between NTB hardware and consumers.

New design allows hardware resources to be split between several consumers.
For example, one BAR can be dedicated for remote memory access, while other
resources can be used for packet transport for virtual Ethernet interface.
And even without resource split, this code allows to specify which consumer
driver should attach the hardware.

From some points this makes the code even closer to Linux one, even though
Linux does not provide the described flexibility.

1 files changed, 16 insertions, 2 deletions

diff --git a/share/man/man4/ntb_hw.4 b/share/man/man4/ntb_hw.4
index 901ee73..b6dffce 100644
--- a/share/man/man4/ntb_hw.4
+++ b/share/man/man4/ntb_hw.4
@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd July 10, 2016
+.Dd July 28, 2016
 .Dt NTB_HW 4
 .Os
 .Sh NAME
@@ -51,6 +51,20 @@ The following tunables are settable from the
 .It Va hw.ntb.debug_level
 Driver debug level.
 The default value is 0, higher means more verbose.
+.It Va hint.ntb_hw. Ns Ar X Ns Va .config
+Configures NTB resources split between several consumer devices.
+Configuration of multiple consumer devices separated by commas.
+Each device can be configured as: "<name>[:<mw>[:<spad>[:<db>]]]", where:
+.Va name
+is a name of the driver which should attach the device (empty means any),
+.Va mw
+is a number of memory windows to allocate (empty means all available),
+.Va spad
+is a number of scratchpad registers to allocate (empty means all available),
+.Va db
+is a number of doorbells to allocate (empty means all available).
+The default configuration is empty string, which means single device
+with all available resources allowing any driver attachment.
 .El
 .Sh DESCRIPTION
 The NTB allows you to connect two computer systems using a PCIe link if they
@@ -69,7 +83,7 @@ The hardware provides 2-3 memory windows to the other system's memory,
 On Xeon processors one of memory windows is typically consumed by the driver
 to workaround multiple hardware erratas.
 .Sh CONFIGURATION
-Tne NTB configuration should be set by BIOS.
+The NTB configuration should be set by BIOS.
 It includes enabling NTB, choosing between NTB-to-NTB or NTB-to-Root Port mode,
 enabling split BAR mode (one of two 64-bit BARs can be split into two 32-bit
 ones) and configuring BAR sizes in bits (from 12 to 29/39) for both NTB sides.