--- /dev/null
+/*
+ * 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)
+ 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;
+}
--- /dev/null
+/*
+ * 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.
+ */
+#ifndef __MLX5_EN_PORT_BUFFER_H__
+#define __MLX5_EN_PORT_BUFFER_H__
+
+#include "en.h"
+#include "port.h"
+
+#define MLX5E_MAX_BUFFER 8
+#define MLX5E_BUFFER_CELL_SHIFT 7
+#define MLX5E_DEFAULT_CABLE_LEN 7 /* 7 meters */
+
+#define MLX5_BUFFER_SUPPORTED(mdev) (MLX5_CAP_GEN(mdev, pcam_reg) && \
+ MLX5_CAP_PCAM_REG(mdev, pbmc) && \
+ MLX5_CAP_PCAM_REG(mdev, pptb))
+
+enum {
+ MLX5E_PORT_BUFFER_CABLE_LEN = BIT(0),
+ MLX5E_PORT_BUFFER_PFC = BIT(1),
+ MLX5E_PORT_BUFFER_PRIO2BUFFER = BIT(2),
+ MLX5E_PORT_BUFFER_SIZE = BIT(3),
+};
+
+struct mlx5e_bufferx_reg {
+ u8 lossy;
+ u8 epsb;
+ u32 size;
+ u32 xoff;
+ u32 xon;
+};
+
+struct mlx5e_port_buffer {
+ u32 port_buffer_size;
+ u32 spare_buffer_size;
+ struct mlx5e_bufferx_reg buffer[MLX5E_MAX_BUFFER];
+};
+
+int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
+ u32 change, unsigned int mtu,
+ struct ieee_pfc *pfc,
+ u32 *buffer_size,
+ u8 *prio2buffer);
+
+int mlx5e_port_query_buffer(struct mlx5e_priv *priv,
+ struct mlx5e_port_buffer *port_buffer);
+#endif