OpenCloudOS-Kernel/drivers/infiniband
David S. Miller bda65b4255 mlx5 4K UAR
The following series of patches optimizes the usage of the UAR area which is
 contained within the BAR 0-1. Previous versions of the firmware and the driver
 assumed each system page contains a single UAR. This patch set will query the
 firmware for a new capability that if published, means that the firmware can
 support UARs of fixed 4K regardless of system page size. In the case of
 powerpc, where page size equals 64KB, this means we can utilize 16 UARs per
 system page. Since user space processes by default consume eight UARs per
 context this means that with this change a process will need a single system
 page to fulfill that requirement and in fact make use of more UARs which is
 better in terms of performance.
 
 In addition to optimizing user-space processes, we introduce an allocator
 that can be used by kernel consumers to allocate blue flame registers
 (which are areas within a UAR that are used to write doorbells). This provides
 further optimization on using the UAR area since the Ethernet driver makes
 use of a single blue flame register per system page and now it will use two
 blue flame registers per 4K.
 
 The series also makes changes to naming conventions and now the terms used in
 the driver code match the terms used in the PRM (programmers reference manual).
 Thus, what used to be called UUAR (micro UAR) is now called BFREG (blue flame
 register).
 
 In order to support compatibility between different versions of
 library/driver/firmware, the library has now means to notify the kernel driver
 that it supports the new scheme and the kernel can notify the library if it
 supports this extension. So mixed versions of libraries can run concurrently
 without any issues.
 
 Thanks,
         Eli and Matan
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Merge tag 'mlx5-4kuar-for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux

Saeed Mahameed says:

====================
mlx5 4K UAR

The following series of patches optimizes the usage of the UAR area which is
contained within the BAR 0-1. Previous versions of the firmware and the driver
assumed each system page contains a single UAR. This patch set will query the
firmware for a new capability that if published, means that the firmware can
support UARs of fixed 4K regardless of system page size. In the case of
powerpc, where page size equals 64KB, this means we can utilize 16 UARs per
system page. Since user space processes by default consume eight UARs per
context this means that with this change a process will need a single system
page to fulfill that requirement and in fact make use of more UARs which is
better in terms of performance.

In addition to optimizing user-space processes, we introduce an allocator
that can be used by kernel consumers to allocate blue flame registers
(which are areas within a UAR that are used to write doorbells). This provides
further optimization on using the UAR area since the Ethernet driver makes
use of a single blue flame register per system page and now it will use two
blue flame registers per 4K.

The series also makes changes to naming conventions and now the terms used in
the driver code match the terms used in the PRM (programmers reference manual).
Thus, what used to be called UUAR (micro UAR) is now called BFREG (blue flame
register).

In order to support compatibility between different versions of
library/driver/firmware, the library has now means to notify the kernel driver
that it supports the new scheme and the kernel can notify the library if it
supports this extension. So mixed versions of libraries can run concurrently
without any issues.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-09 17:09:31 -05:00
..
core Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
hw mlx5 4K UAR 2017-01-09 17:09:31 -05:00
sw First round of -rc fixes for 4.10 kernel 2016-12-23 10:38:48 -08:00
ulp Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
Kconfig IB: Add vmw_pvrdma driver 2016-12-14 14:55:10 -05:00
Makefile IB/rdmavt: Create module framework and handle driver registration 2016-03-10 20:37:04 -05:00