git.openwrt.org Git - openwrt/staging/ldir.git/blob

   1 From ad4944aa0b02cb043afe20bc2a018c161e65c992 Mon Sep 17 00:00:00 2001
   2 From: Miquel Raynal <miquel.raynal@bootlin.com>
   3 Date: Thu, 16 Dec 2021 12:16:38 +0100
   4 Subject: [PATCH 01/15] mtd: nand: ecc: Add infrastructure to support hardware
   5  engines
   6
   7 Add the necessary helpers to register/unregister hardware ECC engines
   8 that will be called from ECC engine drivers.
   9
  10 Also add helpers to get the right engine from the user
  11 perspective. Keep a reference of the in use ECC engine in order to
  12 prevent modules to be unloaded. Put the reference when the engine gets
  13 retired.
  14
  15 A static list of hardware (only) ECC engines is setup to keep track of
  16 the registered engines.
  17
  18 Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
  19 Link: https://lore.kernel.org/linux-mtd/20211216111654.238086-13-miquel.raynal@bootlin.com
  20 (cherry picked from commit 96489c1c0b53131b0e1ec33e2060538379ad6152)
  21 ---
  22  drivers/mtd/nand/core.c  | 10 +++--
  23  drivers/mtd/nand/ecc.c   | 88 ++++++++++++++++++++++++++++++++++++++++
  24  include/linux/mtd/nand.h | 28 +++++++++++++
  25  3 files changed, 123 insertions(+), 3 deletions(-)
  26
  27 --- a/drivers/mtd/nand/core.c
  28 +++ b/drivers/mtd/nand/core.c
  29 @@ -232,7 +232,9 @@ static int nanddev_get_ecc_engine(struct
  30                 nand->ecc.engine = nand_ecc_get_on_die_hw_engine(nand);
  31                 break;
  32         case NAND_ECC_ENGINE_TYPE_ON_HOST:
  33 -               pr_err("On-host hardware ECC engines not supported yet\n");
  34 +               nand->ecc.engine = nand_ecc_get_on_host_hw_engine(nand);
  35 +               if (PTR_ERR(nand->ecc.engine) == -EPROBE_DEFER)
  36 +                       return -EPROBE_DEFER;
  37                 break;
  38         default:
  39                 pr_err("Missing ECC engine type\n");
  40 @@ -252,7 +254,7 @@ static int nanddev_put_ecc_engine(struct
  41  {
  42         switch (nand->ecc.ctx.conf.engine_type) {
  43         case NAND_ECC_ENGINE_TYPE_ON_HOST:
  44 -               pr_err("On-host hardware ECC engines not supported yet\n");
  45 +               nand_ecc_put_on_host_hw_engine(nand);
  46                 break;
  47         case NAND_ECC_ENGINE_TYPE_NONE:
  48         case NAND_ECC_ENGINE_TYPE_SOFT:
  49 @@ -297,7 +299,9 @@ int nanddev_ecc_engine_init(struct nand_
  50         /* Look for the ECC engine to use */
  51         ret = nanddev_get_ecc_engine(nand);
  52         if (ret) {
  53 -               pr_err("No ECC engine found\n");
  54 +               if (ret != -EPROBE_DEFER)
  55 +                       pr_err("No ECC engine found\n");
  56 +
  57                 return ret;
  58         }
  59
  60 --- a/drivers/mtd/nand/ecc.c
  61 +++ b/drivers/mtd/nand/ecc.c
  62 @@ -96,6 +96,12 @@
  63  #include <linux/module.h>
  64  #include <linux/mtd/nand.h>
  65  #include <linux/slab.h>
  66 +#include <linux/of.h>
  67 +#include <linux/of_device.h>
  68 +#include <linux/of_platform.h>
  69 +
  70 +static LIST_HEAD(on_host_hw_engines);
  71 +static DEFINE_MUTEX(on_host_hw_engines_mutex);
  72
  73  /**
  74   * nand_ecc_init_ctx - Init the ECC engine context
  75 @@ -611,6 +617,88 @@ struct nand_ecc_engine *nand_ecc_get_on_
  76  }
  77  EXPORT_SYMBOL(nand_ecc_get_on_die_hw_engine);
  78
  79 +int nand_ecc_register_on_host_hw_engine(struct nand_ecc_engine *engine)
  80 +{
  81 +       struct nand_ecc_engine *item;
  82 +
  83 +       if (!engine)
  84 +               return -EINVAL;
  85 +
  86 +       /* Prevent multiple registrations of one engine */
  87 +       list_for_each_entry(item, &on_host_hw_engines, node)
  88 +               if (item == engine)
  89 +                       return 0;
  90 +
  91 +       mutex_lock(&on_host_hw_engines_mutex);
  92 +       list_add_tail(&engine->node, &on_host_hw_engines);
  93 +       mutex_unlock(&on_host_hw_engines_mutex);
  94 +
  95 +       return 0;
  96 +}
  97 +EXPORT_SYMBOL(nand_ecc_register_on_host_hw_engine);
  98 +
  99 +int nand_ecc_unregister_on_host_hw_engine(struct nand_ecc_engine *engine)
 100 +{
 101 +       if (!engine)
 102 +               return -EINVAL;
 103 +
 104 +       mutex_lock(&on_host_hw_engines_mutex);
 105 +       list_del(&engine->node);
 106 +       mutex_unlock(&on_host_hw_engines_mutex);
 107 +
 108 +       return 0;
 109 +}
 110 +EXPORT_SYMBOL(nand_ecc_unregister_on_host_hw_engine);
 111 +
 112 +static struct nand_ecc_engine *nand_ecc_match_on_host_hw_engine(struct device *dev)
 113 +{
 114 +       struct nand_ecc_engine *item;
 115 +
 116 +       list_for_each_entry(item, &on_host_hw_engines, node)
 117 +               if (item->dev == dev)
 118 +                       return item;
 119 +
 120 +       return NULL;
 121 +}
 122 +
 123 +struct nand_ecc_engine *nand_ecc_get_on_host_hw_engine(struct nand_device *nand)
 124 +{
 125 +       struct nand_ecc_engine *engine = NULL;
 126 +       struct device *dev = &nand->mtd.dev;
 127 +       struct platform_device *pdev;
 128 +       struct device_node *np;
 129 +
 130 +       if (list_empty(&on_host_hw_engines))
 131 +               return NULL;
 132 +
 133 +       /* Check for an explicit nand-ecc-engine property */
 134 +       np = of_parse_phandle(dev->of_node, "nand-ecc-engine", 0);
 135 +       if (np) {
 136 +               pdev = of_find_device_by_node(np);
 137 +               if (!pdev)
 138 +                       return ERR_PTR(-EPROBE_DEFER);
 139 +
 140 +               engine = nand_ecc_match_on_host_hw_engine(&pdev->dev);
 141 +               platform_device_put(pdev);
 142 +               of_node_put(np);
 143 +
 144 +               if (!engine)
 145 +                       return ERR_PTR(-EPROBE_DEFER);
 146 +       }
 147 +
 148 +       if (engine)
 149 +               get_device(engine->dev);
 150 +
 151 +       return engine;
 152 +}
 153 +EXPORT_SYMBOL(nand_ecc_get_on_host_hw_engine);
 154 +
 155 +void nand_ecc_put_on_host_hw_engine(struct nand_device *nand)
 156 +{
 157 +       put_device(nand->ecc.engine->dev);
 158 +}
 159 +EXPORT_SYMBOL(nand_ecc_put_on_host_hw_engine);
 160 +
 161  MODULE_LICENSE("GPL");
 162  MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com>");
 163  MODULE_DESCRIPTION("Generic ECC engine");
 164 --- a/include/linux/mtd/nand.h
 165 +++ b/include/linux/mtd/nand.h
 166 @@ -264,11 +264,35 @@ struct nand_ecc_engine_ops {
 167  };
 168
 169  /**
 170 + * enum nand_ecc_engine_integration - How the NAND ECC engine is integrated
 171 + * @NAND_ECC_ENGINE_INTEGRATION_INVALID: Invalid value
 172 + * @NAND_ECC_ENGINE_INTEGRATION_PIPELINED: Pipelined engine, performs on-the-fly
 173 + *                                         correction, does not need to copy
 174 + *                                         data around
 175 + * @NAND_ECC_ENGINE_INTEGRATION_EXTERNAL: External engine, needs to bring the
 176 + *                                        data into its own area before use
 177 + */
 178 +enum nand_ecc_engine_integration {
 179 +       NAND_ECC_ENGINE_INTEGRATION_INVALID,
 180 +       NAND_ECC_ENGINE_INTEGRATION_PIPELINED,
 181 +       NAND_ECC_ENGINE_INTEGRATION_EXTERNAL,
 182 +};
 183 +
 184 +/**
 185   * struct nand_ecc_engine - ECC engine abstraction for NAND devices
 186 + * @dev: Host device
 187 + * @node: Private field for registration time
 188   * @ops: ECC engine operations
 189 + * @integration: How the engine is integrated with the host
 190 + *               (only relevant on %NAND_ECC_ENGINE_TYPE_ON_HOST engines)
 191 + * @priv: Private data
 192   */
 193  struct nand_ecc_engine {
 194 +       struct device *dev;
 195 +       struct list_head node;
 196         struct nand_ecc_engine_ops *ops;
 197 +       enum nand_ecc_engine_integration integration;
 198 +       void *priv;
 199  };
 200
 201  void of_get_nand_ecc_user_config(struct nand_device *nand);
 202 @@ -279,8 +303,12 @@ int nand_ecc_prepare_io_req(struct nand_
 203  int nand_ecc_finish_io_req(struct nand_device *nand,
 204                            struct nand_page_io_req *req);
 205  bool nand_ecc_is_strong_enough(struct nand_device *nand);
 206 +int nand_ecc_register_on_host_hw_engine(struct nand_ecc_engine *engine);
 207 +int nand_ecc_unregister_on_host_hw_engine(struct nand_ecc_engine *engine);
 208  struct nand_ecc_engine *nand_ecc_get_sw_engine(struct nand_device *nand);
 209  struct nand_ecc_engine *nand_ecc_get_on_die_hw_engine(struct nand_device *nand);
 210 +struct nand_ecc_engine *nand_ecc_get_on_host_hw_engine(struct nand_device *nand);
 211 +void nand_ecc_put_on_host_hw_engine(struct nand_device *nand);
 212
 213  #if IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING)
 214  struct nand_ecc_engine *nand_ecc_sw_hamming_get_engine(void);