drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c - pub/scm/linux/kernel/git/chanwoo/linux - Git at Google

 /*
  * Copyright (c) 2018, Mellanox Technologies. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
  * General Public License (GPL) Version 2, available from the file
  * COPYING in the main directory of this source tree, or the
  * OpenIB.org BSD license below:
  *
  *     Redistribution and use in source and binary forms, with or
  *     without modification, are permitted provided that the following
  *     conditions are met:
  *
  *      - Redistributions of source code must retain the above
  *        copyright notice, this list of conditions and the following
  *        disclaimer.
  *
  *      - Redistributions in binary form must reproduce the above
  *        copyright notice, this list of conditions and the following
  *        disclaimer in the documentation and/or other materials
  *        provided with the distribution.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */
 #include "port_buffer.h"

 int mlx5e_port_query_buffer(struct mlx5e_priv *priv,
 			    struct mlx5e_port_buffer *port_buffer)
 {
 	struct mlx5_core_dev *mdev = priv->mdev;
 	int sz = MLX5_ST_SZ_BYTES(pbmc_reg);
 	u32 total_used = 0;
 	void *buffer;
 	void *out;
 	int err;
 	int i;

 	out = kzalloc(sz, GFP_KERNEL);
 	if (!out)
 		return -ENOMEM;

 	err = mlx5e_port_query_pbmc(mdev, out);
 	if (err)
 		goto out;

 	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
 		buffer = MLX5_ADDR_OF(pbmc_reg, out, buffer[i]);
 		port_buffer->buffer[i].lossy =
 			MLX5_GET(bufferx_reg, buffer, lossy);
 		port_buffer->buffer[i].epsb =
 			MLX5_GET(bufferx_reg, buffer, epsb);
 		port_buffer->buffer[i].size =
 			MLX5_GET(bufferx_reg, buffer, size) << MLX5E_BUFFER_CELL_SHIFT;
 		port_buffer->buffer[i].xon =
 			MLX5_GET(bufferx_reg, buffer, xon_threshold) << MLX5E_BUFFER_CELL_SHIFT;
 		port_buffer->buffer[i].xoff =
 			MLX5_GET(bufferx_reg, buffer, xoff_threshold) << MLX5E_BUFFER_CELL_SHIFT;
 		total_used += port_buffer->buffer[i].size;

 		mlx5e_dbg(HW, priv, "buffer %d: size=%d, xon=%d, xoff=%d, epsb=%d, lossy=%d\n", i,
 			  port_buffer->buffer[i].size,
 			  port_buffer->buffer[i].xon,
 			  port_buffer->buffer[i].xoff,
 			  port_buffer->buffer[i].epsb,
 			  port_buffer->buffer[i].lossy);
 	}

 	port_buffer->port_buffer_size =
 		MLX5_GET(pbmc_reg, out, port_buffer_size) << MLX5E_BUFFER_CELL_SHIFT;
 	port_buffer->spare_buffer_size =
 		port_buffer->port_buffer_size - total_used;

 	mlx5e_dbg(HW, priv, "total buffer size=%d, spare buffer size=%d\n",
 		  port_buffer->port_buffer_size,
 		  port_buffer->spare_buffer_size);
 out:
 	kfree(out);
 	return err;
 }

 static int port_set_buffer(struct mlx5e_priv *priv,
 			   struct mlx5e_port_buffer *port_buffer)
 {
 	struct mlx5_core_dev *mdev = priv->mdev;
 	int sz = MLX5_ST_SZ_BYTES(pbmc_reg);
 	void *buffer;
 	void *in;
 	int err;
 	int i;

 	in = kzalloc(sz, GFP_KERNEL);
 	if (!in)
 		return -ENOMEM;

 	err = mlx5e_port_query_pbmc(mdev, in);
 	if (err)
 		goto out;

 	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
 		buffer = MLX5_ADDR_OF(pbmc_reg, in, buffer[i]);

 		MLX5_SET(bufferx_reg, buffer, size,
 			 port_buffer->buffer[i].size >> MLX5E_BUFFER_CELL_SHIFT);
 		MLX5_SET(bufferx_reg, buffer, lossy,
 			 port_buffer->buffer[i].lossy);
 		MLX5_SET(bufferx_reg, buffer, xoff_threshold,
 			 port_buffer->buffer[i].xoff >> MLX5E_BUFFER_CELL_SHIFT);
 		MLX5_SET(bufferx_reg, buffer, xon_threshold,
 			 port_buffer->buffer[i].xon >> MLX5E_BUFFER_CELL_SHIFT);
 	}

 	err = mlx5e_port_set_pbmc(mdev, in);
 out:
 	kfree(in);
 	return err;
 }

 /* xoff = ((301+2.16 * len [m]) * speed [Gbps] + 2.72 MTU [B]) */
 static u32 calculate_xoff(struct mlx5e_priv *priv, unsigned int mtu)
 {
 	u32 speed;
 	u32 xoff;
 	int err;

 	err = mlx5e_port_linkspeed(priv->mdev, &speed);
 	if (err) {
 		mlx5_core_warn(priv->mdev, "cannot get port speed\n");
 		return 0;
 	}

 	xoff = (301 + 216 * priv->dcbx.cable_len / 100) * speed / 1000 + 272 * mtu / 100;

 	mlx5e_dbg(HW, priv, "%s: xoff=%d\n", __func__, xoff);
 	return xoff;
 }

 static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
 				 u32 xoff, unsigned int mtu)
 {
 	int i;

 	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
 		if (port_buffer->buffer[i].lossy) {
 			port_buffer->buffer[i].xoff = 0;
 			port_buffer->buffer[i].xon  = 0;
 			continue;
 		}

 		if (port_buffer->buffer[i].size <
 		    (xoff + mtu + (1 << MLX5E_BUFFER_CELL_SHIFT)))
 			return -ENOMEM;

 		port_buffer->buffer[i].xoff = port_buffer->buffer[i].size - xoff;
 		port_buffer->buffer[i].xon  = port_buffer->buffer[i].xoff - mtu;
 	}

 	return 0;
 }

 /**
  * update_buffer_lossy()
  *   mtu: device's MTU
  *   pfc_en: <input> current pfc configuration
  *   buffer: <input> current prio to buffer mapping
  *   xoff:   <input> xoff value
  *   port_buffer: <output> port receive buffer configuration
  *   change: <output>
  *
  *   Update buffer configuration based on pfc configuraiton and priority
  *   to buffer mapping.
  *   Buffer's lossy bit is changed to:
  *     lossless if there is at least one PFC enabled priority mapped to this buffer
  *     lossy if all priorities mapped to this buffer are PFC disabled
  *
  *   Return:
  *     Return 0 if no error.
  *     Set change to true if buffer configuration is modified.
  */
 static int update_buffer_lossy(unsigned int mtu,
 			       u8 pfc_en, u8 *buffer, u32 xoff,
 			       struct mlx5e_port_buffer *port_buffer,
 			       bool *change)
 {
 	bool changed = false;
 	u8 lossy_count;
 	u8 prio_count;
 	u8 lossy;
 	int prio;
 	int err;
 	int i;

 	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
 		prio_count = 0;
 		lossy_count = 0;

 		for (prio = 0; prio < MLX5E_MAX_PRIORITY; prio++) {
 			if (buffer[prio] != i)
 				continue;

 			prio_count++;
 			lossy_count += !(pfc_en & (1 << prio));
 		}

 		if (lossy_count == prio_count)
 			lossy = 1;
 		else /* lossy_count < prio_count */
 			lossy = 0;

 		if (lossy != port_buffer->buffer[i].lossy) {
 			port_buffer->buffer[i].lossy = lossy;
 			changed = true;
 		}
 	}

 	if (changed) {
 		err = update_xoff_threshold(port_buffer, xoff, mtu);
 		if (err)
 			return err;

 		*change = true;
 	}

 	return 0;
 }

 int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
 				    u32 change, unsigned int mtu,
 				    struct ieee_pfc *pfc,
 				    u32 *buffer_size,
 				    u8 *prio2buffer)
 {
 	struct mlx5e_port_buffer port_buffer;
 	u32 xoff = calculate_xoff(priv, mtu);
 	bool update_prio2buffer = false;
 	u8 buffer[MLX5E_MAX_PRIORITY];
 	bool update_buffer = false;
 	u32 total_used = 0;
 	u8 curr_pfc_en;
 	int err;
 	int i;

 	mlx5e_dbg(HW, priv, "%s: change=%x\n", __func__, change);

 	err = mlx5e_port_query_buffer(priv, &port_buffer);
 	if (err)
 		return err;

 	if (change & MLX5E_PORT_BUFFER_CABLE_LEN) {
 		update_buffer = true;
 		err = update_xoff_threshold(&port_buffer, xoff, mtu);
 		if (err)
 			return err;
 	}

 	if (change & MLX5E_PORT_BUFFER_PFC) {
 		err = mlx5e_port_query_priority2buffer(priv->mdev, buffer);
 		if (err)
 			return err;

 		err = update_buffer_lossy(mtu, pfc->pfc_en, buffer, xoff,
 					  &port_buffer, &update_buffer);
 		if (err)
 			return err;
 	}

 	if (change & MLX5E_PORT_BUFFER_PRIO2BUFFER) {
 		update_prio2buffer = true;
 		err = mlx5_query_port_pfc(priv->mdev, &curr_pfc_en, NULL);
 		if (err)
 			return err;

 		err = update_buffer_lossy(mtu, curr_pfc_en, prio2buffer, xoff,
 					  &port_buffer, &update_buffer);
 		if (err)
 			return err;
 	}

 	if (change & MLX5E_PORT_BUFFER_SIZE) {
 		for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
 			mlx5e_dbg(HW, priv, "%s: buffer[%d]=%d\n", __func__, i, buffer_size[i]);
 			if (!port_buffer.buffer[i].lossy && !buffer_size[i]) {
 				mlx5e_dbg(HW, priv, "%s: lossless buffer[%d] size cannot be zero\n",
 					  __func__, i);
 				return -EINVAL;
 			}

 			port_buffer.buffer[i].size = buffer_size[i];
 			total_used += buffer_size[i];
 		}

 		mlx5e_dbg(HW, priv, "%s: total buffer requested=%d\n", __func__, total_used);

 		if (total_used > port_buffer.port_buffer_size)
 			return -EINVAL;

 		update_buffer = true;
 		err = update_xoff_threshold(&port_buffer, xoff, mtu);
 		if (err)
 			return err;
 	}

 	/* Need to update buffer configuration if xoff value is changed */
 	if (!update_buffer && xoff != priv->dcbx.xoff) {
 		update_buffer = true;
 		err = update_xoff_threshold(&port_buffer, xoff, mtu);
 		if (err)
 			return err;
 	}
 	priv->dcbx.xoff = xoff;

 	/* Apply the settings */
 	if (update_buffer) {
 		err = port_set_buffer(priv, &port_buffer);
 		if (err)
 			return err;
 	}

 	if (update_prio2buffer)
 		err = mlx5e_port_set_priority2buffer(priv->mdev, prio2buffer);

 	return err;
 }
	/*
	* Copyright (c) 2018, Mellanox Technologies. All rights reserved.
	*
	* This software is available to you under a choice of one of two
	* licenses. You may choose to be licensed under the terms of the GNU
	* General Public License (GPL) Version 2, available from the file
	* COPYING in the main directory of this source tree, or the
	* OpenIB.org BSD license below:
	*
	* Redistribution and use in source and binary forms, with or
	* without modification, are permitted provided that the following
	* conditions are met:
	*
	* - Redistributions of source code must retain the above
	* copyright notice, this list of conditions and the following
	* disclaimer.
	*
	* - Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following
	* disclaimer in the documentation and/or other materials
	* provided with the distribution.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	* SOFTWARE.
	*/
	#include "port_buffer.h"

	int mlx5e_port_query_buffer(struct mlx5e_priv *priv,
	struct mlx5e_port_buffer *port_buffer)
	{
	struct mlx5_core_dev *mdev = priv->mdev;
	int sz = MLX5_ST_SZ_BYTES(pbmc_reg);
	u32 total_used = 0;
	void *buffer;
	void *out;
	int err;
	int i;

	out = kzalloc(sz, GFP_KERNEL);
	if (!out)
	return -ENOMEM;

	err = mlx5e_port_query_pbmc(mdev, out);
	if (err)
	goto out;

	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
	buffer = MLX5_ADDR_OF(pbmc_reg, out, buffer[i]);
	port_buffer->buffer[i].lossy =
	MLX5_GET(bufferx_reg, buffer, lossy);
	port_buffer->buffer[i].epsb =
	MLX5_GET(bufferx_reg, buffer, epsb);
	port_buffer->buffer[i].size =
	MLX5_GET(bufferx_reg, buffer, size) << MLX5E_BUFFER_CELL_SHIFT;
	port_buffer->buffer[i].xon =
	MLX5_GET(bufferx_reg, buffer, xon_threshold) << MLX5E_BUFFER_CELL_SHIFT;
	port_buffer->buffer[i].xoff =
	MLX5_GET(bufferx_reg, buffer, xoff_threshold) << MLX5E_BUFFER_CELL_SHIFT;
	total_used += port_buffer->buffer[i].size;

	mlx5e_dbg(HW, priv, "buffer %d: size=%d, xon=%d, xoff=%d, epsb=%d, lossy=%d\n", i,
	port_buffer->buffer[i].size,
	port_buffer->buffer[i].xon,
	port_buffer->buffer[i].xoff,
	port_buffer->buffer[i].epsb,
	port_buffer->buffer[i].lossy);
	}

	port_buffer->port_buffer_size =
	MLX5_GET(pbmc_reg, out, port_buffer_size) << MLX5E_BUFFER_CELL_SHIFT;
	port_buffer->spare_buffer_size =
	port_buffer->port_buffer_size - total_used;

	mlx5e_dbg(HW, priv, "total buffer size=%d, spare buffer size=%d\n",
	port_buffer->port_buffer_size,
	port_buffer->spare_buffer_size);
	out:
	kfree(out);
	return err;
	}

	static int port_set_buffer(struct mlx5e_priv *priv,
	struct mlx5e_port_buffer *port_buffer)
	{
	struct mlx5_core_dev *mdev = priv->mdev;
	int sz = MLX5_ST_SZ_BYTES(pbmc_reg);
	void *buffer;
	void *in;
	int err;
	int i;

	in = kzalloc(sz, GFP_KERNEL);
	if (!in)
	return -ENOMEM;

	err = mlx5e_port_query_pbmc(mdev, in);
	if (err)
	goto out;

	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
	buffer = MLX5_ADDR_OF(pbmc_reg, in, buffer[i]);

	MLX5_SET(bufferx_reg, buffer, size,
	port_buffer->buffer[i].size >> MLX5E_BUFFER_CELL_SHIFT);
	MLX5_SET(bufferx_reg, buffer, lossy,
	port_buffer->buffer[i].lossy);
	MLX5_SET(bufferx_reg, buffer, xoff_threshold,
	port_buffer->buffer[i].xoff >> MLX5E_BUFFER_CELL_SHIFT);
	MLX5_SET(bufferx_reg, buffer, xon_threshold,
	port_buffer->buffer[i].xon >> MLX5E_BUFFER_CELL_SHIFT);
	}

	err = mlx5e_port_set_pbmc(mdev, in);
	out:
	kfree(in);
	return err;
	}

	/* xoff = ((301+2.16 * len [m]) * speed [Gbps] + 2.72 MTU [B]) */
	static u32 calculate_xoff(struct mlx5e_priv *priv, unsigned int mtu)
	{
	u32 speed;
	u32 xoff;
	int err;

	err = mlx5e_port_linkspeed(priv->mdev, &speed);
	if (err) {
	mlx5_core_warn(priv->mdev, "cannot get port speed\n");
	return 0;
	}

	xoff = (301 + 216 * priv->dcbx.cable_len / 100) * speed / 1000 + 272 * mtu / 100;

	mlx5e_dbg(HW, priv, "%s: xoff=%d\n", __func__, xoff);
	return xoff;
	}

	static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
	u32 xoff, unsigned int mtu)
	{
	int i;

	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
	if (port_buffer->buffer[i].lossy) {
	port_buffer->buffer[i].xoff = 0;
	port_buffer->buffer[i].xon = 0;
	continue;
	}

	if (port_buffer->buffer[i].size <
	(xoff + mtu + (1 << MLX5E_BUFFER_CELL_SHIFT)))
	return -ENOMEM;

	port_buffer->buffer[i].xoff = port_buffer->buffer[i].size - xoff;
	port_buffer->buffer[i].xon = port_buffer->buffer[i].xoff - mtu;
	}

	return 0;
	}

	/**
	* update_buffer_lossy()
	* mtu: device's MTU
	* pfc_en: <input> current pfc configuration
	* buffer: <input> current prio to buffer mapping
	* xoff: <input> xoff value
	* port_buffer: <output> port receive buffer configuration
	* change: <output>
	*
	* Update buffer configuration based on pfc configuraiton and priority
	* to buffer mapping.
	* Buffer's lossy bit is changed to:
	* lossless if there is at least one PFC enabled priority mapped to this buffer
	* lossy if all priorities mapped to this buffer are PFC disabled
	*
	* Return:
	* Return 0 if no error.
	* Set change to true if buffer configuration is modified.
	*/
	static int update_buffer_lossy(unsigned int mtu,
	u8 pfc_en, u8 *buffer, u32 xoff,
	struct mlx5e_port_buffer *port_buffer,
	bool *change)
	{
	bool changed = false;
	u8 lossy_count;
	u8 prio_count;
	u8 lossy;
	int prio;
	int err;
	int i;

	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
	prio_count = 0;
	lossy_count = 0;

	for (prio = 0; prio < MLX5E_MAX_PRIORITY; prio++) {
	if (buffer[prio] != i)
	continue;

	prio_count++;
	lossy_count += !(pfc_en & (1 << prio));
	}

	if (lossy_count == prio_count)
	lossy = 1;
	else /* lossy_count < prio_count */
	lossy = 0;

	if (lossy != port_buffer->buffer[i].lossy) {
	port_buffer->buffer[i].lossy = lossy;
	changed = true;
	}
	}

	if (changed) {
	err = update_xoff_threshold(port_buffer, xoff, mtu);
	if (err)
	return err;

	*change = true;
	}

	return 0;
	}

	int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
	u32 change, unsigned int mtu,
	struct ieee_pfc *pfc,
	u32 *buffer_size,
	u8 *prio2buffer)
	{
	struct mlx5e_port_buffer port_buffer;
	u32 xoff = calculate_xoff(priv, mtu);
	bool update_prio2buffer = false;
	u8 buffer[MLX5E_MAX_PRIORITY];
	bool update_buffer = false;
	u32 total_used = 0;
	u8 curr_pfc_en;
	int err;
	int i;

	mlx5e_dbg(HW, priv, "%s: change=%x\n", __func__, change);

	err = mlx5e_port_query_buffer(priv, &port_buffer);
	if (err)
	return err;

	if (change & MLX5E_PORT_BUFFER_CABLE_LEN) {
	update_buffer = true;
	err = update_xoff_threshold(&port_buffer, xoff, mtu);
	if (err)
	return err;
	}

	if (change & MLX5E_PORT_BUFFER_PFC) {
	err = mlx5e_port_query_priority2buffer(priv->mdev, buffer);
	if (err)
	return err;

	err = update_buffer_lossy(mtu, pfc->pfc_en, buffer, xoff,
	&port_buffer, &update_buffer);
	if (err)
	return err;
	}

	if (change & MLX5E_PORT_BUFFER_PRIO2BUFFER) {
	update_prio2buffer = true;
	err = mlx5_query_port_pfc(priv->mdev, &curr_pfc_en, NULL);
	if (err)
	return err;

	err = update_buffer_lossy(mtu, curr_pfc_en, prio2buffer, xoff,
	&port_buffer, &update_buffer);
	if (err)
	return err;
	}

	if (change & MLX5E_PORT_BUFFER_SIZE) {
	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
	mlx5e_dbg(HW, priv, "%s: buffer[%d]=%d\n", __func__, i, buffer_size[i]);
	if (!port_buffer.buffer[i].lossy && !buffer_size[i]) {
	mlx5e_dbg(HW, priv, "%s: lossless buffer[%d] size cannot be zero\n",
	__func__, i);
	return -EINVAL;
	}

	port_buffer.buffer[i].size = buffer_size[i];
	total_used += buffer_size[i];
	}

	mlx5e_dbg(HW, priv, "%s: total buffer requested=%d\n", __func__, total_used);

	if (total_used > port_buffer.port_buffer_size)
	return -EINVAL;

	update_buffer = true;
	err = update_xoff_threshold(&port_buffer, xoff, mtu);
	if (err)
	return err;
	}

	/* Need to update buffer configuration if xoff value is changed */
	if (!update_buffer && xoff != priv->dcbx.xoff) {
	update_buffer = true;
	err = update_xoff_threshold(&port_buffer, xoff, mtu);
	if (err)
	return err;
	}
	priv->dcbx.xoff = xoff;

	/* Apply the settings */
	if (update_buffer) {
	err = port_set_buffer(priv, &port_buffer);
	if (err)
	return err;
	}

	if (update_prio2buffer)
	err = mlx5e_port_set_priority2buffer(priv->mdev, prio2buffer);

	return err;
	}