Linux PCI Non-Transparent Bridge framework and drivers
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* RE: [PATCH v2 9/9] NTB: Add ntb.h comments
@ 2016-12-13  4:14 Allen Hubbe
  0 siblings, 0 replies; 2+ messages in thread
From: Allen Hubbe @ 2016-12-13  4:14 UTC (permalink / raw)
  To: 'Serge Semin', jdmason, dave.jiang, Xiangliang.Yu
  Cc: Sergey.Semin, linux-ntb, linux-kernel

From: Serge Semin
> 
> Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
> 
> ---
>  include/linux/ntb.h | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/include/linux/ntb.h b/include/linux/ntb.h
> index fe0437c..c5a369c 100644
> --- a/include/linux/ntb.h
> +++ b/include/linux/ntb.h
> @@ -312,13 +312,18 @@ static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops
> *ops)
>  {
>  	/* commented callbacks are not required: */
>  	return
> +		/* Port operations are required */

Maybe: are required for multiport devices.

>  		ops->port_number			&&
>  		ops->peer_port_count			&&
>  		ops->peer_port_number			&&
>  		ops->peer_port_idx			&&
> +
> +		/* Link operations are requiered */
>  		ops->link_is_up				&&
>  		ops->link_enable			&&
>  		ops->link_disable			&&

Wasn't the first patch in this series all about making link ops first?

> +
> +		/* One or both MW interfaces should be developed */
>  		ops->mw_count				&&
>  		ops->mw_get_align			&&
>  		(ops->mw_set_trans			||
> @@ -328,12 +333,11 @@ static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops
> *ops)
>  		ops->peer_mw_get_addr			&&
>  		/* ops->peer_mw_clear_trans		&& */
> 
> +		/* Doorbell operations are mostly required */
>  		/* ops->db_is_unsafe			&& */
>  		ops->db_valid_mask			&&
> -
>  		/* both set, or both unset */
>  		(!ops->db_vector_count == !ops->db_vector_mask) &&
> -
>  		ops->db_read				&&
>  		/* ops->db_set				&& */
>  		ops->db_clear				&&
> @@ -347,6 +351,8 @@ static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops *ops)
>  		/* ops->peer_db_read_mask		&& */
>  		/* ops->peer_db_set_mask		&& */
>  		/* ops->peer_db_clear_mask		&& */
> +
> +		/* Scrachpad interface is optional */
>  		/* !ops->spad_is_unsafe == !ops->spad_count && */
>  		!ops->spad_read == !ops->spad_count	&&
>  		!ops->spad_write == !ops->spad_count	&&
> @@ -354,6 +360,7 @@ static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops *ops)
>  		/* !ops->peer_spad_read == !ops->spad_count && */
>  		!ops->peer_spad_write == !ops->spad_count &&
> 
> +		/* Message registers interface is optional */
>  		!ops->msg_inbits == !ops->msg_count	&&
>  		!ops->msg_outbits == !ops->msg_count	&&
>  		!ops->msg_read_sts == !ops->msg_count	&&
> @@ -374,13 +381,12 @@ struct ntb_client {
>  	struct device_driver		drv;
>  	const struct ntb_client_ops	ops;
>  };
> -
>  #define drv_ntb_client(__drv) container_of((__drv), struct ntb_client, drv)
> 
>  /**
>   * struct ntb_device - ntb device
>   * @dev:		Linux device object.
> - * @pdev:		Pci device entry of the ntb.
> + * @pdev:		PCI device entry of the ntb.
>   * @topo:		Detected topology of the ntb.
>   * @ops:		See &ntb_dev_ops.
>   * @ctx:		See &ntb_ctx_ops.
> @@ -401,7 +407,6 @@ struct ntb_dev {
>  	/* block unregister until device is fully released */
>  	struct completion		released;
>  };
> -
>  #define dev_ntb(__dev) container_of((__dev), struct ntb_dev, dev)
> 
>  /**
> @@ -498,7 +503,7 @@ void ntb_link_event(struct ntb_dev *ntb);
>   * multiple interrupt vectors for doorbells, the vector number indicates which
>   * vector received the interrupt.  The vector number is relative to the first
>   * vector used for doorbells, starting at zero, and must be less than
> - ** ntb_db_vector_count().  The driver may call ntb_db_read() to check which
> + * ntb_db_vector_count().  The driver may call ntb_db_read() to check which
>   * doorbell bits need service, and ntb_db_vector_mask() to determine which of
>   * those bits are associated with the vector number.
>   */
> --
> 2.6.6



^ permalink raw reply	[flat|nested] 2+ messages in thread
* [PATCH 00/22] NTB: Alter kernel API to support multi-port devices
@ 2016-11-29 17:15 Serge Semin
  2016-12-12 21:08 ` [PATCH v2 0/9] " Serge Semin
  0 siblings, 1 reply; 2+ messages in thread
From: Serge Semin @ 2016-11-29 17:15 UTC (permalink / raw)
  To: jdmason, dave.jiang, Allen.Hubbe, Xiangliang.Yu
  Cc: Sergey.Semin, linux-ntb, linux-kernel, Serge Semin

There are devices, like IDT PCIe-switches, which have more than just two ports.
Particularly one device can have up to eight ports with NTB-function activated.
In order to support such devices, NTB kernel API should be altered since
currently it's optimized to work with two-ports devices only.

Here are the changes I made to conform the design we discussed a few months ago:

1) Port-index-related methods are added to KAPI
 ntb_port_number();
 ntb_peer_port_count();
 ntb_peer_port_number(pdix);
 ntb_peer_port_idx(port);

2) Link state method returns bitfield of link states for each reachable port
 u64 ntb_link_is_up();
 
3) Link enable/disable methods work with local link side of NTB
 ntb_link_enable()/ntb_link_disable();
 
4) NTB memory window related interface does the following things
 ntb_mw_count(pidx); - number of inbound memory windows, which can be allocated
for shared buffer with specified peer device.
 ntb_mw_get_align(pidx, widx); - get alignment and size restrition parameters
to properly allocate inbound memory region.
 ntb_peer_mw_count(); - get number of outbound memory windows.
 ntb_peer_mw_get_addr(widx); - get mapping address of an outbound memory window 

Inbound MW based hardware:
 ntb_mw_set_trans(pidx, widx); - set translation address of allocated inbound
memory window so a peer device could access it.
 ntb_mw_clear_trans(pidx, widx); - clear the translation address of an inbound
memory window.

Outbound MW based hardware:
 ntb_peer_mw_set_trans(pidx, widx); - set translation address of a memory
window retrieved from a peer device
 ntb_peer_mw_clear_trans(pidx, widx); - clear the translation address of an
outbound memory window

5) Scratchpad interface needs to support multi-port devices as well
 ntb_spad_count() - return number of Scratchpad per each port
 ntb_peer_spad_addr(pidx, sidx) - address of Scratchpad register of the
peer device with pidx-index
 ntb_peer_spad_read(pidx, sidx) - read specified Scratchpad register of the
peer with pidx-index
 ntb_peer_spad_write(pidx, sidx) - write data to Scratchpad register of the
peer with pidx-index

6) Introduce new messaging interface of NTB KAPI
 ntb_msg_count(); - get number of message registers
 ntb_msg_inbits(); - get bitfield of inbound message registers status
 ntb_msg_outbits(); - get bitfield of outbound message registers status
 ntb_msg_read_sts(); - read the inbound and outbound message registers status
 ntb_msg_clear_sts(); - clear status bits of message registers
 ntb_msg_set_mask(); - mask interrupts raised by status bits of message
registers.
 ntb_msg_clear_mask(); - clear interrupts mask bits of message registers
 ntb_msg_recv(midx, *pidx); - read message register with specified index,
additionally getting peer port index which data received from
 ntb_msg_send(midx, pidx); - write data to the specified message register
sending it to the passed peer device connected over a pidx port
 ntb_msg_event(); - notify driver context of a new message event
 
7) Topology reduced to be either P2P (port-to-port) or B2B (bridge-to-bridge).
Since there is port number introduced to be part of ntb_dev structure, real
port number can be used to determine Primary and Secondary sides. Intel and AMD
driver are altered to support this novation.

8) Standard test drivers: PingPong, Debugging tool and Raw Perf as well as NTB
Transport drivers don't support multi-port devices at the moment.
Since we haven't got any real multi-port hadrware driver, it's dangerous to
make any serious alterations in the debugging tools. So I have made those
drivers to work the way they wokred before, but using the new NTB API.
The situation will change when I finish porting my current IDT NTB driver to
support new API. Then I'll be able to refactor the tools and test them using
real multi-port hardware.

The changes are made on top of the NTB-fork of the kernel:
https://github.com/jonmason/ntb
of "ntb"-branch with last commit:
9c763584b7c8911106bb77af7e648bef09af9d80 Linux 4.9-rc6

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>

Serge Semin (22):
  NTB: Move link state API being first in sources
  NTB: Add peer indexed ports NTB API
  NTB: Alter NTB API to support both inbound and outbound MW based
    interfaces
  NTB: Add messaging NTB API
  NTB: Alter Scratchpads NTB API to support multi-ports interface
  NTB: Slightly alter link state NTB API
  NTB: Fix a few ntb.h issues
  NTB: Add T-Platforms copyrights to NTB API
  NTB Intel: Move link-related methods being first in the driver
  NTB Intel: Add port-related NTB API callback methods
  NTB Intel: Alter MW interface to fit new NTB API
  NTB Intel: Alter Scratchpads interface to fit new NTB API
  NTB Intel: Add T-Platforms copyrights to Intel NTB driver
  NTB AMD: Move link-related methods being first in the driver
  NTB AMD: Add port-related NTB API callback methods
  NTB AMD: Alter MW interface to fit new NTB API
  NTB AMD: Alter Scratchpads interface to fit new NTB API
  NTB AMD: Add T-Platforms copyrights to AMD NTB driver
  NTB PingPong: Alter driver to work with two-ports NTB API
  NTB Tool: Alter driver to work with two-ports NTB API
  NTB Perf: Alter driver to work with two-ports NTB API
  NTB Transport: Alter driver to work with two-ports NTB API

 drivers/ntb/hw/amd/ntb_hw_amd.c     | 310 +++++++++------
 drivers/ntb/hw/amd/ntb_hw_amd.h     |  12 +
 drivers/ntb/hw/intel/ntb_hw_intel.c | 420 ++++++++++++--------
 drivers/ntb/hw/intel/ntb_hw_intel.h |  12 +
 drivers/ntb/ntb.c                   |  15 +
 drivers/ntb/ntb_transport.c         |  43 +-
 drivers/ntb/test/ntb_perf.c         |  27 +-
 drivers/ntb/test/ntb_pingpong.c     |  11 +-
 drivers/ntb/test/ntb_tool.c         |  87 +++--
 include/linux/ntb.h                 | 753 +++++++++++++++++++++++++++++-------
 10 files changed, 1221 insertions(+), 469 deletions(-)

-- 
2.6.6


^ permalink raw reply	[flat|nested] 2+ messages in thread
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2016-12-13  4:14 [PATCH v2 9/9] NTB: Add ntb.h comments Allen Hubbe
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2016-11-29 17:15 [PATCH 00/22] NTB: Alter kernel API to support multi-port devices Serge Semin
2016-12-12 21:08 ` [PATCH v2 0/9] " Serge Semin
2016-12-12 21:08   ` [PATCH v2 9/9] NTB: Add ntb.h comments Serge Semin

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