Merge branch 'for-v5.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/ebieder...
[linux-2.6-microblaze.git] / drivers / net / ethernet / mellanox / mlxsw / spectrum_buffers.c
index 6f84557..37ff29a 100644 (file)
@@ -121,6 +121,10 @@ struct mlxsw_sp_sb_vals {
        unsigned int cms_cpu_count;
 };
 
+struct mlxsw_sp_sb_ops {
+       u32 (*int_buf_size_get)(int mtu, u32 speed);
+};
+
 u32 mlxsw_sp_cells_bytes(const struct mlxsw_sp *mlxsw_sp, u32 cells)
 {
        return mlxsw_sp->sb->cell_size * cells;
@@ -131,9 +135,14 @@ u32 mlxsw_sp_bytes_cells(const struct mlxsw_sp *mlxsw_sp, u32 bytes)
        return DIV_ROUND_UP(bytes, mlxsw_sp->sb->cell_size);
 }
 
-u32 mlxsw_sp_sb_max_headroom_cells(const struct mlxsw_sp *mlxsw_sp)
+static u32 mlxsw_sp_port_headroom_8x_adjust(const struct mlxsw_sp_port *mlxsw_sp_port,
+                                           u32 size_cells)
 {
-       return mlxsw_sp->sb->max_headroom_cells;
+       /* Ports with eight lanes use two headroom buffers between which the
+        * configured headroom size is split. Therefore, multiply the calculated
+        * headroom size by two.
+        */
+       return mlxsw_sp_port->mapping.width == 8 ? 2 * size_cells : size_cells;
 }
 
 static struct mlxsw_sp_sb_pr *mlxsw_sp_sb_pr_get(struct mlxsw_sp *mlxsw_sp,
@@ -291,55 +300,308 @@ static int mlxsw_sp_sb_pm_occ_query(struct mlxsw_sp *mlxsw_sp, u8 local_port,
                                     (unsigned long) pm);
 }
 
-/* 1/4 of a headroom necessary for 100Gbps port and 100m cable. */
-#define MLXSW_SP_PB_HEADROOM 25632
+void mlxsw_sp_hdroom_prios_reset_buf_idx(struct mlxsw_sp_hdroom *hdroom)
+{
+       int prio;
+
+       for (prio = 0; prio < IEEE_8021QAZ_MAX_TCS; prio++) {
+               switch (hdroom->mode) {
+               case MLXSW_SP_HDROOM_MODE_DCB:
+                       hdroom->prios.prio[prio].buf_idx = hdroom->prios.prio[prio].ets_buf_idx;
+                       break;
+               case MLXSW_SP_HDROOM_MODE_TC:
+                       hdroom->prios.prio[prio].buf_idx = hdroom->prios.prio[prio].set_buf_idx;
+                       break;
+               }
+       }
+}
+
+void mlxsw_sp_hdroom_bufs_reset_lossiness(struct mlxsw_sp_hdroom *hdroom)
+{
+       int prio;
+       int i;
+
+       for (i = 0; i < DCBX_MAX_BUFFERS; i++)
+               hdroom->bufs.buf[i].lossy = true;
+
+       for (prio = 0; prio < IEEE_8021Q_MAX_PRIORITIES; prio++) {
+               if (!hdroom->prios.prio[prio].lossy)
+                       hdroom->bufs.buf[hdroom->prios.prio[prio].buf_idx].lossy = false;
+       }
+}
+
+static u16 mlxsw_sp_hdroom_buf_threshold_get(const struct mlxsw_sp *mlxsw_sp, int mtu)
+{
+       return 2 * mlxsw_sp_bytes_cells(mlxsw_sp, mtu);
+}
+
+static void mlxsw_sp_hdroom_buf_pack(char *pbmc_pl, int index, u16 size, u16 thres, bool lossy)
+{
+       if (lossy)
+               mlxsw_reg_pbmc_lossy_buffer_pack(pbmc_pl, index, size);
+       else
+               mlxsw_reg_pbmc_lossless_buffer_pack(pbmc_pl, index, size,
+                                                   thres);
+}
+
+static u16 mlxsw_sp_hdroom_buf_delay_get(const struct mlxsw_sp *mlxsw_sp,
+                                        const struct mlxsw_sp_hdroom *hdroom)
+{
+       u16 delay_cells;
+
+       delay_cells = mlxsw_sp_bytes_cells(mlxsw_sp, hdroom->delay_bytes);
+
+       /* In the worst case scenario the delay will be made up of packets that
+        * are all of size CELL_SIZE + 1, which means each packet will require
+        * almost twice its true size when buffered in the switch. We therefore
+        * multiply this value by the "cell factor", which is close to 2.
+        *
+        * Another MTU is added in case the transmitting host already started
+        * transmitting a maximum length frame when the PFC packet was received.
+        */
+       return 2 * delay_cells + mlxsw_sp_bytes_cells(mlxsw_sp, hdroom->mtu);
+}
+
+static u32 mlxsw_sp_hdroom_int_buf_size_get(struct mlxsw_sp *mlxsw_sp, int mtu, u32 speed)
+{
+       u32 buffsize = mlxsw_sp->sb_ops->int_buf_size_get(speed, mtu);
+
+       return mlxsw_sp_bytes_cells(mlxsw_sp, buffsize) + 1;
+}
+
+static bool mlxsw_sp_hdroom_buf_is_used(const struct mlxsw_sp_hdroom *hdroom, int buf)
+{
+       int prio;
+
+       for (prio = 0; prio < IEEE_8021QAZ_MAX_TCS; prio++) {
+               if (hdroom->prios.prio[prio].buf_idx == buf)
+                       return true;
+       }
+       return false;
+}
+
+void mlxsw_sp_hdroom_bufs_reset_sizes(struct mlxsw_sp_port *mlxsw_sp_port,
+                                     struct mlxsw_sp_hdroom *hdroom)
+{
+       struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+       u16 reserve_cells;
+       int i;
+
+       /* Internal buffer. */
+       reserve_cells = mlxsw_sp_hdroom_int_buf_size_get(mlxsw_sp, mlxsw_sp_port->max_speed,
+                                                        mlxsw_sp_port->max_mtu);
+       reserve_cells = mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, reserve_cells);
+       hdroom->int_buf.reserve_cells = reserve_cells;
+
+       if (hdroom->int_buf.enable)
+               hdroom->int_buf.size_cells = reserve_cells;
+       else
+               hdroom->int_buf.size_cells = 0;
+
+       /* PG buffers. */
+       for (i = 0; i < DCBX_MAX_BUFFERS; i++) {
+               struct mlxsw_sp_hdroom_buf *buf = &hdroom->bufs.buf[i];
+               u16 thres_cells;
+               u16 delay_cells;
+
+               if (!mlxsw_sp_hdroom_buf_is_used(hdroom, i)) {
+                       thres_cells = 0;
+                       delay_cells = 0;
+               } else if (buf->lossy) {
+                       thres_cells = mlxsw_sp_hdroom_buf_threshold_get(mlxsw_sp, hdroom->mtu);
+                       delay_cells = 0;
+               } else {
+                       thres_cells = mlxsw_sp_hdroom_buf_threshold_get(mlxsw_sp, hdroom->mtu);
+                       delay_cells = mlxsw_sp_hdroom_buf_delay_get(mlxsw_sp, hdroom);
+               }
+
+               thres_cells = mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, thres_cells);
+               delay_cells = mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, delay_cells);
+
+               buf->thres_cells = thres_cells;
+               if (hdroom->mode == MLXSW_SP_HDROOM_MODE_DCB) {
+                       buf->size_cells = thres_cells + delay_cells;
+               } else {
+                       /* Do not allow going below the minimum size, even if
+                        * the user requested it.
+                        */
+                       buf->size_cells = max(buf->set_size_cells, buf->thres_cells);
+               }
+       }
+}
+
 #define MLXSW_SP_PB_UNUSED 8
 
-static int mlxsw_sp_port_pb_init(struct mlxsw_sp_port *mlxsw_sp_port)
+static int mlxsw_sp_hdroom_configure_buffers(struct mlxsw_sp_port *mlxsw_sp_port,
+                                            const struct mlxsw_sp_hdroom *hdroom, bool force)
 {
-       const u32 pbs[] = {
-               [0] = MLXSW_SP_PB_HEADROOM * mlxsw_sp_port->mapping.width,
-               [9] = MLXSW_PORT_MAX_MTU,
-       };
        struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
        char pbmc_pl[MLXSW_REG_PBMC_LEN];
+       bool dirty;
+       int err;
        int i;
 
-       mlxsw_reg_pbmc_pack(pbmc_pl, mlxsw_sp_port->local_port,
-                           0xffff, 0xffff / 2);
-       for (i = 0; i < ARRAY_SIZE(pbs); i++) {
-               u16 size = mlxsw_sp_bytes_cells(mlxsw_sp, pbs[i]);
+       dirty = memcmp(&mlxsw_sp_port->hdroom->bufs, &hdroom->bufs, sizeof(hdroom->bufs));
+       if (!dirty && !force)
+               return 0;
+
+       mlxsw_reg_pbmc_pack(pbmc_pl, mlxsw_sp_port->local_port, 0xffff, 0xffff / 2);
+       for (i = 0; i < MLXSW_SP_PB_COUNT; i++) {
+               const struct mlxsw_sp_hdroom_buf *buf = &hdroom->bufs.buf[i];
 
                if (i == MLXSW_SP_PB_UNUSED)
                        continue;
-               size = mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, size);
-               mlxsw_reg_pbmc_lossy_buffer_pack(pbmc_pl, i, size);
+
+               mlxsw_sp_hdroom_buf_pack(pbmc_pl, i, buf->size_cells, buf->thres_cells, buf->lossy);
        }
-       mlxsw_reg_pbmc_lossy_buffer_pack(pbmc_pl,
-                                        MLXSW_REG_PBMC_PORT_SHARED_BUF_IDX, 0);
-       return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(pbmc), pbmc_pl);
+
+       mlxsw_reg_pbmc_lossy_buffer_pack(pbmc_pl, MLXSW_REG_PBMC_PORT_SHARED_BUF_IDX, 0);
+       err = mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(pbmc), pbmc_pl);
+       if (err)
+               return err;
+
+       mlxsw_sp_port->hdroom->bufs = hdroom->bufs;
+       return 0;
 }
 
-static int mlxsw_sp_port_pb_prio_init(struct mlxsw_sp_port *mlxsw_sp_port)
+static int mlxsw_sp_hdroom_configure_priomap(struct mlxsw_sp_port *mlxsw_sp_port,
+                                            const struct mlxsw_sp_hdroom *hdroom, bool force)
 {
        char pptb_pl[MLXSW_REG_PPTB_LEN];
-       int i;
+       bool dirty;
+       int prio;
+       int err;
+
+       dirty = memcmp(&mlxsw_sp_port->hdroom->prios, &hdroom->prios, sizeof(hdroom->prios));
+       if (!dirty && !force)
+               return 0;
 
        mlxsw_reg_pptb_pack(pptb_pl, mlxsw_sp_port->local_port);
-       for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++)
-               mlxsw_reg_pptb_prio_to_buff_pack(pptb_pl, i, 0);
-       return mlxsw_reg_write(mlxsw_sp_port->mlxsw_sp->core, MLXSW_REG(pptb),
-                              pptb_pl);
+       for (prio = 0; prio < IEEE_8021QAZ_MAX_TCS; prio++)
+               mlxsw_reg_pptb_prio_to_buff_pack(pptb_pl, prio, hdroom->prios.prio[prio].buf_idx);
+
+       err = mlxsw_reg_write(mlxsw_sp_port->mlxsw_sp->core, MLXSW_REG(pptb), pptb_pl);
+       if (err)
+               return err;
+
+       mlxsw_sp_port->hdroom->prios = hdroom->prios;
+       return 0;
 }
 
-static int mlxsw_sp_port_headroom_init(struct mlxsw_sp_port *mlxsw_sp_port)
+static int mlxsw_sp_hdroom_configure_int_buf(struct mlxsw_sp_port *mlxsw_sp_port,
+                                            const struct mlxsw_sp_hdroom *hdroom, bool force)
+{
+       char sbib_pl[MLXSW_REG_SBIB_LEN];
+       bool dirty;
+       int err;
+
+       dirty = memcmp(&mlxsw_sp_port->hdroom->int_buf, &hdroom->int_buf, sizeof(hdroom->int_buf));
+       if (!dirty && !force)
+               return 0;
+
+       mlxsw_reg_sbib_pack(sbib_pl, mlxsw_sp_port->local_port, hdroom->int_buf.size_cells);
+       err = mlxsw_reg_write(mlxsw_sp_port->mlxsw_sp->core, MLXSW_REG(sbib), sbib_pl);
+       if (err)
+               return err;
+
+       mlxsw_sp_port->hdroom->int_buf = hdroom->int_buf;
+       return 0;
+}
+
+static bool mlxsw_sp_hdroom_bufs_fit(struct mlxsw_sp *mlxsw_sp,
+                                    const struct mlxsw_sp_hdroom *hdroom)
 {
+       u32 taken_headroom_cells = 0;
+       int i;
+
+       for (i = 0; i < MLXSW_SP_PB_COUNT; i++)
+               taken_headroom_cells += hdroom->bufs.buf[i].size_cells;
+
+       taken_headroom_cells += hdroom->int_buf.reserve_cells;
+       return taken_headroom_cells <= mlxsw_sp->sb->max_headroom_cells;
+}
+
+static int __mlxsw_sp_hdroom_configure(struct mlxsw_sp_port *mlxsw_sp_port,
+                                      const struct mlxsw_sp_hdroom *hdroom, bool force)
+{
+       struct mlxsw_sp_hdroom orig_hdroom;
+       struct mlxsw_sp_hdroom tmp_hdroom;
        int err;
+       int i;
+
+       /* Port buffers need to be configured in three steps. First, all buffers
+        * with non-zero size are configured. Then, prio-to-buffer map is
+        * updated, allowing traffic to flow to the now non-zero buffers.
+        * Finally, zero-sized buffers are configured, because now no traffic
+        * should be directed to them anymore. This way, in a non-congested
+        * system, no packet drops are introduced by the reconfiguration.
+        */
 
-       err = mlxsw_sp_port_pb_init(mlxsw_sp_port);
+       orig_hdroom = *mlxsw_sp_port->hdroom;
+       tmp_hdroom = orig_hdroom;
+       for (i = 0; i < MLXSW_SP_PB_COUNT; i++) {
+               if (hdroom->bufs.buf[i].size_cells)
+                       tmp_hdroom.bufs.buf[i] = hdroom->bufs.buf[i];
+       }
+
+       if (!mlxsw_sp_hdroom_bufs_fit(mlxsw_sp_port->mlxsw_sp, &tmp_hdroom) ||
+           !mlxsw_sp_hdroom_bufs_fit(mlxsw_sp_port->mlxsw_sp, hdroom))
+               return -ENOBUFS;
+
+       err = mlxsw_sp_hdroom_configure_buffers(mlxsw_sp_port, &tmp_hdroom, force);
        if (err)
                return err;
-       return mlxsw_sp_port_pb_prio_init(mlxsw_sp_port);
+
+       err = mlxsw_sp_hdroom_configure_priomap(mlxsw_sp_port, hdroom, force);
+       if (err)
+               goto err_configure_priomap;
+
+       err = mlxsw_sp_hdroom_configure_buffers(mlxsw_sp_port, hdroom, false);
+       if (err)
+               goto err_configure_buffers;
+
+       err = mlxsw_sp_hdroom_configure_int_buf(mlxsw_sp_port, hdroom, false);
+       if (err)
+               goto err_configure_int_buf;
+
+       *mlxsw_sp_port->hdroom = *hdroom;
+       return 0;
+
+err_configure_int_buf:
+       mlxsw_sp_hdroom_configure_buffers(mlxsw_sp_port, &tmp_hdroom, false);
+err_configure_buffers:
+       mlxsw_sp_hdroom_configure_priomap(mlxsw_sp_port, &tmp_hdroom, false);
+err_configure_priomap:
+       mlxsw_sp_hdroom_configure_buffers(mlxsw_sp_port, &orig_hdroom, false);
+       return err;
+}
+
+int mlxsw_sp_hdroom_configure(struct mlxsw_sp_port *mlxsw_sp_port,
+                             const struct mlxsw_sp_hdroom *hdroom)
+{
+       return __mlxsw_sp_hdroom_configure(mlxsw_sp_port, hdroom, false);
+}
+
+static int mlxsw_sp_port_headroom_init(struct mlxsw_sp_port *mlxsw_sp_port)
+{
+       struct mlxsw_sp *mlxsw_sp = mlxsw_sp_port->mlxsw_sp;
+       struct mlxsw_sp_hdroom hdroom = {};
+       u32 size9;
+       int prio;
+
+       hdroom.mtu = mlxsw_sp_port->dev->mtu;
+       hdroom.mode = MLXSW_SP_HDROOM_MODE_DCB;
+       for (prio = 0; prio < IEEE_8021QAZ_MAX_TCS; prio++)
+               hdroom.prios.prio[prio].lossy = true;
+
+       mlxsw_sp_hdroom_bufs_reset_lossiness(&hdroom);
+       mlxsw_sp_hdroom_bufs_reset_sizes(mlxsw_sp_port, &hdroom);
+
+       /* Buffer 9 is used for control traffic. */
+       size9 = mlxsw_sp_port_headroom_8x_adjust(mlxsw_sp_port, mlxsw_sp_port->max_mtu);
+       hdroom.bufs.buf[9].size_cells = mlxsw_sp_bytes_cells(mlxsw_sp, size9);
+
+       return __mlxsw_sp_hdroom_configure(mlxsw_sp_port, &hdroom, true);
 }
 
 static int mlxsw_sp_sb_port_init(struct mlxsw_sp *mlxsw_sp,
@@ -916,6 +1178,46 @@ const struct mlxsw_sp_sb_vals mlxsw_sp2_sb_vals = {
        .cms_cpu_count = ARRAY_SIZE(mlxsw_sp_cpu_port_sb_cms),
 };
 
+static u32 mlxsw_sp1_pb_int_buf_size_get(int mtu, u32 speed)
+{
+       return mtu * 5 / 2;
+}
+
+static u32 __mlxsw_sp_pb_int_buf_size_get(int mtu, u32 speed, u32 buffer_factor)
+{
+       return 3 * mtu + buffer_factor * speed / 1000;
+}
+
+#define MLXSW_SP2_SPAN_EG_MIRROR_BUFFER_FACTOR 38
+
+static u32 mlxsw_sp2_pb_int_buf_size_get(int mtu, u32 speed)
+{
+       int factor = MLXSW_SP2_SPAN_EG_MIRROR_BUFFER_FACTOR;
+
+       return __mlxsw_sp_pb_int_buf_size_get(mtu, speed, factor);
+}
+
+#define MLXSW_SP3_SPAN_EG_MIRROR_BUFFER_FACTOR 50
+
+static u32 mlxsw_sp3_pb_int_buf_size_get(int mtu, u32 speed)
+{
+       int factor = MLXSW_SP3_SPAN_EG_MIRROR_BUFFER_FACTOR;
+
+       return __mlxsw_sp_pb_int_buf_size_get(mtu, speed, factor);
+}
+
+const struct mlxsw_sp_sb_ops mlxsw_sp1_sb_ops = {
+       .int_buf_size_get = mlxsw_sp1_pb_int_buf_size_get,
+};
+
+const struct mlxsw_sp_sb_ops mlxsw_sp2_sb_ops = {
+       .int_buf_size_get = mlxsw_sp2_pb_int_buf_size_get,
+};
+
+const struct mlxsw_sp_sb_ops mlxsw_sp3_sb_ops = {
+       .int_buf_size_get = mlxsw_sp3_pb_int_buf_size_get,
+};
+
 int mlxsw_sp_buffers_init(struct mlxsw_sp *mlxsw_sp)
 {
        u32 max_headroom_size;
@@ -995,17 +1297,34 @@ int mlxsw_sp_port_buffers_init(struct mlxsw_sp_port *mlxsw_sp_port)
 {
        int err;
 
+       mlxsw_sp_port->hdroom = kzalloc(sizeof(*mlxsw_sp_port->hdroom), GFP_KERNEL);
+       if (!mlxsw_sp_port->hdroom)
+               return -ENOMEM;
+       mlxsw_sp_port->hdroom->mtu = mlxsw_sp_port->dev->mtu;
+
        err = mlxsw_sp_port_headroom_init(mlxsw_sp_port);
        if (err)
-               return err;
+               goto err_headroom_init;
        err = mlxsw_sp_port_sb_cms_init(mlxsw_sp_port);
        if (err)
-               return err;
+               goto err_port_sb_cms_init;
        err = mlxsw_sp_port_sb_pms_init(mlxsw_sp_port);
+       if (err)
+               goto err_port_sb_pms_init;
+       return 0;
 
+err_port_sb_pms_init:
+err_port_sb_cms_init:
+err_headroom_init:
+       kfree(mlxsw_sp_port->hdroom);
        return err;
 }
 
+void mlxsw_sp_port_buffers_fini(struct mlxsw_sp_port *mlxsw_sp_port)
+{
+       kfree(mlxsw_sp_port->hdroom);
+}
+
 int mlxsw_sp_sb_pool_get(struct mlxsw_core *mlxsw_core,
                         unsigned int sb_index, u16 pool_index,
                         struct devlink_sb_pool_info *pool_info)