Huy Nguyen 85743f1eb3 net/mlx4_core: Set UAR page size to 4KB regardless of system page size ... problem description: The current code sets UAR page size equal to system page size. The ConnectX-3 and ConnectX-3 Pro HWs require minimum 128 UAR pages. The mlx4 kernel drivers are not loaded if there is less than 128 UAR pages. solution: Always set UAR page to 4KB. This allows more UAR pages if the OS has PAGE_SIZE larger than 4KB. For example, PowerPC kernel use 64KB system page size, with 4MB uar region, there are 4MB/2/64KB = 32 uars (half for uar, half for blueflame). This does not meet minimum 128 UAR pages requirement. With 4KB UAR page, there are 4MB/2/4KB = 512 uars which meet the minimum requirement. Note that only codes in mlx4_core that deal with firmware know that uar page size is 4KB. Codes that deal with usr page in cq and qp context (mlx4_ib, mlx4_en and part of mlx4_core) still have the same assumption that uar page size equals to system page size. Note that with this implementation, on 64KB system page size kernel, there are 16 uars per system page but only one uars is used. The other 15 uars are ignored because of the above assumption. Regarding SR-IOV, mlx4_core in hypervisor will set the uar page size to 4KB and mlx4_core code in virtual OS will obtain the uar page size from firmware. Regarding backward compatibility in SR-IOV, if hypervisor has this new code, the virtual OS must be updated. If hypervisor has old code, and the virtual OS has this new code, the new code will be backward compatible with the old code. If the uar size is big enough, this new code in VF continues to work with 64 KB uar page size (on PowerPc kernel). If the uar size does not meet 128 uars requirement, this new code not loaded in VF and print the same error message as the old code in Hypervisor. Signed-off-by: Huy Nguyen <huyn@mellanox.com> Reviewed-by: Yishai Hadas <yishaih@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2016-02-17 10:29:27 -05:00
..
core	IB/sysfs: remove unused va_list args	2016-02-04 07:09:07 -05:00
hw	net/mlx4_core: Set UAR page size to 4KB regardless of system page size	2016-02-17 10:29:27 -05:00
ulp	IB/IPoIB: Do not set skb truesize since using one linearskb	2016-02-04 07:08:12 -05:00
Kconfig	IB/cma: Add configfs for rdma_cm	2015-12-23 10:39:52 -05:00
Makefile