drivers/net/ethernet/ti/k3-cppi-desc-pool.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* TI K3 CPPI5 descriptors pool API
   3  *
   4  * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com
   5  */
   6
   7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   8
   9 #include <linux/device.h>
  10 #include <linux/dma-mapping.h>
  11 #include <linux/err.h>
  12 #include <linux/genalloc.h>
  13 #include <linux/kernel.h>
  14
  15 #include "k3-cppi-desc-pool.h"
  16
  17 struct k3_cppi_desc_pool {
  18         struct device           *dev;
  19         dma_addr_t              dma_addr;
  20         void                    *cpumem;        /* dma_alloc map */
  21         size_t                  desc_size;
  22         size_t                  mem_size;
  23         size_t                  num_desc;
  24         struct gen_pool         *gen_pool;
  25 };
  26
  27 void k3_cppi_desc_pool_destroy(struct k3_cppi_desc_pool *pool)
  28 {
  29         if (!pool)
  30                 return;
  31
  32         WARN(gen_pool_size(pool->gen_pool) != gen_pool_avail(pool->gen_pool),
  33              "k3_knav_desc_pool size %zu != avail %zu",
  34              gen_pool_size(pool->gen_pool),
  35              gen_pool_avail(pool->gen_pool));
  36         if (pool->cpumem)
  37                 dma_free_coherent(pool->dev, pool->mem_size, pool->cpumem,
  38                                   pool->dma_addr);
  39
  40         gen_pool_destroy(pool->gen_pool);       /* frees pool->name */
  41 }
  42 EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_destroy);
  43
  44 struct k3_cppi_desc_pool *
  45 k3_cppi_desc_pool_create_name(struct device *dev, size_t size,
  46                               size_t desc_size,
  47                               const char *name)
  48 {
  49         struct k3_cppi_desc_pool *pool;
  50         const char *pool_name = NULL;
  51         int ret = -ENOMEM;
  52
  53         pool = devm_kzalloc(dev, sizeof(*pool), GFP_KERNEL);
  54         if (!pool)
  55                 return ERR_PTR(ret);
  56
  57         pool->dev = dev;
  58         pool->desc_size = roundup_pow_of_two(desc_size);
  59         pool->num_desc  = size;
  60         pool->mem_size  = pool->num_desc * pool->desc_size;
  61
  62         pool_name = kstrdup_const(name ? name : dev_name(pool->dev),
  63                                   GFP_KERNEL);
  64         if (!pool_name)
  65                 return ERR_PTR(-ENOMEM);
  66
  67         pool->gen_pool = gen_pool_create(ilog2(pool->desc_size), -1);
  68         if (!pool->gen_pool) {
  69                 ret = -ENOMEM;
  70                 dev_err(pool->dev, "pool create failed %d\n", ret);
  71                 kfree_const(pool_name);
  72                 goto gen_pool_create_fail;
  73         }
  74
  75         pool->gen_pool->name = pool_name;
  76
  77         pool->cpumem = dma_alloc_coherent(pool->dev, pool->mem_size,
  78                                           &pool->dma_addr, GFP_KERNEL);
  79
  80         if (!pool->cpumem)
  81                 goto dma_alloc_fail;
  82
  83         ret = gen_pool_add_virt(pool->gen_pool, (unsigned long)pool->cpumem,
  84                                 (phys_addr_t)pool->dma_addr, pool->mem_size,
  85                                 -1);
  86         if (ret < 0) {
  87                 dev_err(pool->dev, "pool add failed %d\n", ret);
  88                 goto gen_pool_add_virt_fail;
  89         }
  90
  91         return pool;
  92
  93 gen_pool_add_virt_fail:
  94         dma_free_coherent(pool->dev, pool->mem_size, pool->cpumem,
  95                           pool->dma_addr);
  96 dma_alloc_fail:
  97         gen_pool_destroy(pool->gen_pool);       /* frees pool->name */
  98 gen_pool_create_fail:
  99         devm_kfree(pool->dev, pool);
 100         return ERR_PTR(ret);
 101 }
 102 EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_create_name);
 103
 104 dma_addr_t k3_cppi_desc_pool_virt2dma(struct k3_cppi_desc_pool *pool,
 105                                       void *addr)
 106 {
 107         return addr ? pool->dma_addr + (addr - pool->cpumem) : 0;
 108 }
 109 EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_virt2dma);
 110
 111 void *k3_cppi_desc_pool_dma2virt(struct k3_cppi_desc_pool *pool, dma_addr_t dma)
 112 {
 113         return dma ? pool->cpumem + (dma - pool->dma_addr) : NULL;
 114 }
 115 EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_dma2virt);
 116
 117 void *k3_cppi_desc_pool_alloc(struct k3_cppi_desc_pool *pool)
 118 {
 119         return (void *)gen_pool_alloc(pool->gen_pool, pool->desc_size);
 120 }
 121 EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_alloc);
 122
 123 void k3_cppi_desc_pool_free(struct k3_cppi_desc_pool *pool, void *addr)
 124 {
 125         gen_pool_free(pool->gen_pool, (unsigned long)addr, pool->desc_size);
 126 }
 127 EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_free);
 128
 129 size_t k3_cppi_desc_pool_avail(struct k3_cppi_desc_pool *pool)
 130 {
 131         return gen_pool_avail(pool->gen_pool) / pool->desc_size;
 132 }
 133 EXPORT_SYMBOL_GPL(k3_cppi_desc_pool_avail);
 134
 135 MODULE_LICENSE("GPL");
 136 MODULE_DESCRIPTION("TI K3 CPPI5 descriptors pool API");