Quelle  spectrum_policer.c   Sprache: C

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/* Copyright (c) 2020 Mellanox Technologies. All rights reserved */

#include <linux/idr.h>
#include <linux/log2.h>
#include <linux/mutex.h>
#include <linux/netlink.h>
#include <net/devlink.h>

#include "spectrum.h"

struct mlxsw_sp_policer_family {
 enum mlxsw_sp_policer_type type;
 enum mlxsw_reg_qpcr_g qpcr_type;
 struct mlxsw_sp *mlxsw_sp;
 u16 start_index; /* Inclusive */
 u16 end_index; /* Exclusive */
 struct idr policer_idr;
 struct mutex lock; /* Protects policer_idr */
 atomic_t policers_count;
 const struct mlxsw_sp_policer_family_ops *ops;
};

struct mlxsw_sp_policer {
 struct mlxsw_sp_policer_params params;
 u16 index;
};

struct mlxsw_sp_policer_family_ops {
 int (*init)(struct mlxsw_sp_policer_family *family);
 void (*fini)(struct mlxsw_sp_policer_family *family);
 int (*policer_index_alloc)(struct mlxsw_sp_policer_family *family,
       struct mlxsw_sp_policer *policer);
 struct mlxsw_sp_policer * (*policer_index_free)(struct mlxsw_sp_policer_family *family,
       u16 policer_index);
 int (*policer_init)(struct mlxsw_sp_policer_family *family,
       const struct mlxsw_sp_policer *policer);
 int (*policer_params_check)(const struct mlxsw_sp_policer_family *family,
        const struct mlxsw_sp_policer_params *params,
        struct netlink_ext_ack *extack);
};

struct mlxsw_sp_policer_core {
 struct mlxsw_sp_policer_family *family_arr[MLXSW_SP_POLICER_TYPE_MAX + 1];
 const struct mlxsw_sp_policer_core_ops *ops;
 u8 lowest_bs_bits;
 u8 highest_bs_bits;
};

struct mlxsw_sp_policer_core_ops {
 int (*init)(struct mlxsw_sp_policer_core *policer_core);
};

static u64 mlxsw_sp_policer_rate_bytes_ps_kbps(u64 rate_bytes_ps)
{
 return div_u64(rate_bytes_ps, 1000) * BITS_PER_BYTE;
}

static u8 mlxsw_sp_policer_burst_bytes_hw_units(u64 burst_bytes)
{
 /* Provided burst size is in bytes. The ASIC burst size value is
 * (2 ^ bs) * 512 bits. Convert the provided size to 512-bit units.
 */
 u64 bs512 = div_u64(burst_bytes, 64);

 if (!bs512)
  return 0;

 return fls64(bs512) - 1;
}

static u64 mlxsw_sp_policer_single_rate_occ_get(void *priv)
{
 struct mlxsw_sp_policer_family *family = priv;

 return atomic_read(&family->policers_count);
}

static int
mlxsw_sp_policer_single_rate_family_init(struct mlxsw_sp_policer_family *family)
{
 struct mlxsw_core *core = family->mlxsw_sp->core;
 struct devlink *devlink;

 /* CPU policers are allocated from the first N policers in the global
 * range, so skip them.
 */
 if (!MLXSW_CORE_RES_VALID(core, MAX_GLOBAL_POLICERS) ||
     !MLXSW_CORE_RES_VALID(core, MAX_CPU_POLICERS))
  return -EIO;

 family->start_index = MLXSW_CORE_RES_GET(core, MAX_CPU_POLICERS);
 family->end_index = MLXSW_CORE_RES_GET(core, MAX_GLOBAL_POLICERS);

 atomic_set(&family->policers_count, 0);
 devlink = priv_to_devlink(core);
 devl_resource_occ_get_register(devlink,
           MLXSW_SP_RESOURCE_SINGLE_RATE_POLICERS,
           mlxsw_sp_policer_single_rate_occ_get,
           family);

 return 0;
}

static void
mlxsw_sp_policer_single_rate_family_fini(struct mlxsw_sp_policer_family *family)
{
 struct devlink *devlink = priv_to_devlink(family->mlxsw_sp->core);

 devl_resource_occ_get_unregister(devlink,
      MLXSW_SP_RESOURCE_SINGLE_RATE_POLICERS);
 WARN_ON(atomic_read(&family->policers_count) != 0);
}

static int
mlxsw_sp_policer_single_rate_index_alloc(struct mlxsw_sp_policer_family *family,
      struct mlxsw_sp_policer *policer)
{
 int id;

 mutex_lock(&family->lock);
 id = idr_alloc(&family->policer_idr, policer, family->start_index,
         family->end_index, GFP_KERNEL);
 mutex_unlock(&family->lock);

 if (id < 0)
  return id;

 atomic_inc(&family->policers_count);
 policer->index = id;

 return 0;
}

static struct mlxsw_sp_policer *
mlxsw_sp_policer_single_rate_index_free(struct mlxsw_sp_policer_family *family,
     u16 policer_index)
{
 struct mlxsw_sp_policer *policer;

 atomic_dec(&family->policers_count);

 mutex_lock(&family->lock);
 policer = idr_remove(&family->policer_idr, policer_index);
 mutex_unlock(&family->lock);

 WARN_ON(!policer);

 return policer;
}

static int
mlxsw_sp_policer_single_rate_init(struct mlxsw_sp_policer_family *family,
      const struct mlxsw_sp_policer *policer)
{
 u64 rate_kbps = mlxsw_sp_policer_rate_bytes_ps_kbps(policer->params.rate);
 u8 bs = mlxsw_sp_policer_burst_bytes_hw_units(policer->params.burst);
 struct mlxsw_sp *mlxsw_sp = family->mlxsw_sp;
 char qpcr_pl[MLXSW_REG_QPCR_LEN];

 mlxsw_reg_qpcr_pack(qpcr_pl, policer->index, MLXSW_REG_QPCR_IR_UNITS_K,
       true, rate_kbps, bs);
 mlxsw_reg_qpcr_clear_counter_set(qpcr_pl, true);

 return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(qpcr), qpcr_pl);
}

static int
mlxsw_sp_policer_single_rate_params_check(const struct mlxsw_sp_policer_family *family,
       const struct mlxsw_sp_policer_params *params,
       struct netlink_ext_ack *extack)
{
 struct mlxsw_sp_policer_core *policer_core = family->mlxsw_sp->policer_core;
 u64 rate_bps = params->rate * BITS_PER_BYTE;
 u8 bs;

 if (!params->bytes) {
  NL_SET_ERR_MSG_MOD(extack, "Only bandwidth policing is currently supported by single rate policers");
  return -EINVAL;
 }

 if (!is_power_of_2(params->burst)) {
  NL_SET_ERR_MSG_MOD(extack, "Policer burst size is not power of two");
  return -EINVAL;
 }

 bs = mlxsw_sp_policer_burst_bytes_hw_units(params->burst);

 if (bs < policer_core->lowest_bs_bits) {
  NL_SET_ERR_MSG_MOD(extack, "Policer burst size lower than limit");
  return -EINVAL;
 }

 if (bs > policer_core->highest_bs_bits) {
  NL_SET_ERR_MSG_MOD(extack, "Policer burst size higher than limit");
  return -EINVAL;
 }

 if (rate_bps < MLXSW_REG_QPCR_LOWEST_CIR_BITS) {
  NL_SET_ERR_MSG_MOD(extack, "Policer rate lower than limit");
  return -EINVAL;
 }

 if (rate_bps > MLXSW_REG_QPCR_HIGHEST_CIR_BITS) {
  NL_SET_ERR_MSG_MOD(extack, "Policer rate higher than limit");
  return -EINVAL;
 }

 return 0;
}

static const struct mlxsw_sp_policer_family_ops mlxsw_sp_policer_single_rate_ops = {
 .init   = mlxsw_sp_policer_single_rate_family_init,
 .fini   = mlxsw_sp_policer_single_rate_family_fini,
 .policer_index_alloc = mlxsw_sp_policer_single_rate_index_alloc,
 .policer_index_free = mlxsw_sp_policer_single_rate_index_free,
 .policer_init  = mlxsw_sp_policer_single_rate_init,
 .policer_params_check = mlxsw_sp_policer_single_rate_params_check,
};

static const struct mlxsw_sp_policer_family mlxsw_sp_policer_single_rate_family = {
 .type  = MLXSW_SP_POLICER_TYPE_SINGLE_RATE,
 .qpcr_type = MLXSW_REG_QPCR_G_GLOBAL,
 .ops  = &mlxsw_sp_policer_single_rate_ops,
};

static const struct mlxsw_sp_policer_family *mlxsw_sp_policer_family_arr[] = {
 [MLXSW_SP_POLICER_TYPE_SINGLE_RATE] = &mlxsw_sp_policer_single_rate_family,
};

int mlxsw_sp_policer_add(struct mlxsw_sp *mlxsw_sp,
    enum mlxsw_sp_policer_type type,
    const struct mlxsw_sp_policer_params *params,
    struct netlink_ext_ack *extack, u16 *p_policer_index)
{
 struct mlxsw_sp_policer_family *family;
 struct mlxsw_sp_policer *policer;
 int err;

 family = mlxsw_sp->policer_core->family_arr[type];

 err = family->ops->policer_params_check(family, params, extack);
 if (err)
  return err;

 policer = kmalloc(sizeof(*policer), GFP_KERNEL);
 if (!policer)
  return -ENOMEM;
 policer->params = *params;

 err = family->ops->policer_index_alloc(family, policer);
 if (err) {
  NL_SET_ERR_MSG_MOD(extack, "Failed to allocate policer index");
  goto err_policer_index_alloc;
 }

 err = family->ops->policer_init(family, policer);
 if (err) {
  NL_SET_ERR_MSG_MOD(extack, "Failed to initialize policer");
  goto err_policer_init;
 }

 *p_policer_index = policer->index;

 return 0;

err_policer_init:
 family->ops->policer_index_free(family, policer->index);
err_policer_index_alloc:
 kfree(policer);
 return err;
}

void mlxsw_sp_policer_del(struct mlxsw_sp *mlxsw_sp,
     enum mlxsw_sp_policer_type type, u16 policer_index)
{
 struct mlxsw_sp_policer_family *family;
 struct mlxsw_sp_policer *policer;

 family = mlxsw_sp->policer_core->family_arr[type];
 policer = family->ops->policer_index_free(family, policer_index);
 kfree(policer);
}

int mlxsw_sp_policer_drops_counter_get(struct mlxsw_sp *mlxsw_sp,
           enum mlxsw_sp_policer_type type,
           u16 policer_index, u64 *p_drops)
{
 struct mlxsw_sp_policer_family *family;
 char qpcr_pl[MLXSW_REG_QPCR_LEN];
 int err;

 family = mlxsw_sp->policer_core->family_arr[type];

 MLXSW_REG_ZERO(qpcr, qpcr_pl);
 mlxsw_reg_qpcr_pid_set(qpcr_pl, policer_index);
 mlxsw_reg_qpcr_g_set(qpcr_pl, family->qpcr_type);
 err = mlxsw_reg_query(mlxsw_sp->core, MLXSW_REG(qpcr), qpcr_pl);
 if (err)
  return err;

 *p_drops = mlxsw_reg_qpcr_violate_count_get(qpcr_pl);

 return 0;
}

static int
mlxsw_sp_policer_family_register(struct mlxsw_sp *mlxsw_sp,
     const struct mlxsw_sp_policer_family *tmpl)
{
 struct mlxsw_sp_policer_family *family;
 int err;

 family = kmemdup(tmpl, sizeof(*family), GFP_KERNEL);
 if (!family)
  return -ENOMEM;

 family->mlxsw_sp = mlxsw_sp;
 idr_init(&family->policer_idr);
 mutex_init(&family->lock);

 err = family->ops->init(family);
 if (err)
  goto err_family_init;

 if (WARN_ON(family->start_index >= family->end_index)) {
  err = -EINVAL;
  goto err_index_check;
 }

 mlxsw_sp->policer_core->family_arr[tmpl->type] = family;

 return 0;

err_index_check:
 family->ops->fini(family);
err_family_init:
 mutex_destroy(&family->lock);
 idr_destroy(&family->policer_idr);
 kfree(family);
 return err;
}

static void
mlxsw_sp_policer_family_unregister(struct mlxsw_sp *mlxsw_sp,
       struct mlxsw_sp_policer_family *family)
{
 family->ops->fini(family);
 mutex_destroy(&family->lock);
 WARN_ON(!idr_is_empty(&family->policer_idr));
 idr_destroy(&family->policer_idr);
 kfree(family);
}

int mlxsw_sp_policers_init(struct mlxsw_sp *mlxsw_sp)
{
 struct mlxsw_sp_policer_core *policer_core;
 int i, err;

 policer_core = kzalloc(sizeof(*policer_core), GFP_KERNEL);
 if (!policer_core)
  return -ENOMEM;
 mlxsw_sp->policer_core = policer_core;
 policer_core->ops = mlxsw_sp->policer_core_ops;

 err = policer_core->ops->init(policer_core);
 if (err)
  goto err_init;

 for (i = 0; i < MLXSW_SP_POLICER_TYPE_MAX + 1; i++) {
  err = mlxsw_sp_policer_family_register(mlxsw_sp, mlxsw_sp_policer_family_arr[i]);
  if (err)
   goto err_family_register;
 }

 return 0;

err_family_register:
 for (i--; i >= 0; i--) {
  struct mlxsw_sp_policer_family *family;

  family = mlxsw_sp->policer_core->family_arr[i];
  mlxsw_sp_policer_family_unregister(mlxsw_sp, family);
 }
err_init:
 kfree(mlxsw_sp->policer_core);
 return err;
}

void mlxsw_sp_policers_fini(struct mlxsw_sp *mlxsw_sp)
{
 int i;

 for (i = MLXSW_SP_POLICER_TYPE_MAX; i >= 0; i--) {
  struct mlxsw_sp_policer_family *family;

  family = mlxsw_sp->policer_core->family_arr[i];
  mlxsw_sp_policer_family_unregister(mlxsw_sp, family);
 }

 kfree(mlxsw_sp->policer_core);
}

int mlxsw_sp_policer_resources_register(struct mlxsw_core *mlxsw_core)
{
 u64 global_policers, cpu_policers, single_rate_policers;
 struct devlink *devlink = priv_to_devlink(mlxsw_core);
 struct devlink_resource_size_params size_params;
 int err;

 if (!MLXSW_CORE_RES_VALID(mlxsw_core, MAX_GLOBAL_POLICERS) ||
     !MLXSW_CORE_RES_VALID(mlxsw_core, MAX_CPU_POLICERS))
  return -EIO;

 global_policers = MLXSW_CORE_RES_GET(mlxsw_core, MAX_GLOBAL_POLICERS);
 cpu_policers = MLXSW_CORE_RES_GET(mlxsw_core, MAX_CPU_POLICERS);
 single_rate_policers = global_policers - cpu_policers;

 devlink_resource_size_params_init(&size_params, global_policers,
       global_policers, 1,
       DEVLINK_RESOURCE_UNIT_ENTRY);
 err = devl_resource_register(devlink, "global_policers",
         global_policers,
         MLXSW_SP_RESOURCE_GLOBAL_POLICERS,
         DEVLINK_RESOURCE_ID_PARENT_TOP,
         &size_params);
 if (err)
  return err;

 devlink_resource_size_params_init(&size_params, single_rate_policers,
       single_rate_policers, 1,
       DEVLINK_RESOURCE_UNIT_ENTRY);
 err = devl_resource_register(devlink, "single_rate_policers",
         single_rate_policers,
         MLXSW_SP_RESOURCE_SINGLE_RATE_POLICERS,
         MLXSW_SP_RESOURCE_GLOBAL_POLICERS,
         &size_params);
 if (err)
  return err;

 return 0;
}

static int
mlxsw_sp1_policer_core_init(struct mlxsw_sp_policer_core *policer_core)
{
 policer_core->lowest_bs_bits = MLXSW_REG_QPCR_LOWEST_CBS_BITS_SP1;
 policer_core->highest_bs_bits = MLXSW_REG_QPCR_HIGHEST_CBS_BITS_SP1;

 return 0;
}

const struct mlxsw_sp_policer_core_ops mlxsw_sp1_policer_core_ops = {
 .init = mlxsw_sp1_policer_core_init,
};

static int
mlxsw_sp2_policer_core_init(struct mlxsw_sp_policer_core *policer_core)
{
 policer_core->lowest_bs_bits = MLXSW_REG_QPCR_LOWEST_CBS_BITS_SP2;
 policer_core->highest_bs_bits = MLXSW_REG_QPCR_HIGHEST_CBS_BITS_SP2;

 return 0;
}

const struct mlxsw_sp_policer_core_ops mlxsw_sp2_policer_core_ops = {
 .init = mlxsw_sp2_policer_core_init,
};