git.openwrt.org Git - openwrt/staging/dedeckeh.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 diff --git a/drivers/mtd/nand/core.c b/drivers/mtd/nand/core.c
  28 index 5e13a03d2b32..b228b4d13b7a 100644
  29 --- a/drivers/mtd/nand/core.c
  30 +++ b/drivers/mtd/nand/core.c
  31 @@ -232,7 +232,9 @@ static int nanddev_get_ecc_engine(struct nand_device *nand)
  32                 nand->ecc.engine = nand_ecc_get_on_die_hw_engine(nand);
  33                 break;
  34         case NAND_ECC_ENGINE_TYPE_ON_HOST:
  35 -               pr_err("On-host hardware ECC engines not supported yet\n");
  36 +               nand->ecc.engine = nand_ecc_get_on_host_hw_engine(nand);
  37 +               if (PTR_ERR(nand->ecc.engine) == -EPROBE_DEFER)
  38 +                       return -EPROBE_DEFER;
  39                 break;
  40         default:
  41                 pr_err("Missing ECC engine type\n");
  42 @@ -252,7 +254,7 @@ static int nanddev_put_ecc_engine(struct nand_device *nand)
  43  {
  44         switch (nand->ecc.ctx.conf.engine_type) {
  45         case NAND_ECC_ENGINE_TYPE_ON_HOST:
  46 -               pr_err("On-host hardware ECC engines not supported yet\n");
  47 +               nand_ecc_put_on_host_hw_engine(nand);
  48                 break;
  49         case NAND_ECC_ENGINE_TYPE_NONE:
  50         case NAND_ECC_ENGINE_TYPE_SOFT:
  51 @@ -297,7 +299,9 @@ int nanddev_ecc_engine_init(struct nand_device *nand)
  52         /* Look for the ECC engine to use */
  53         ret = nanddev_get_ecc_engine(nand);
  54         if (ret) {
  55 -               pr_err("No ECC engine found\n");
  56 +               if (ret != -EPROBE_DEFER)
  57 +                       pr_err("No ECC engine found\n");
  58 +
  59                 return ret;
  60         }
  61
  62 diff --git a/drivers/mtd/nand/ecc.c b/drivers/mtd/nand/ecc.c
  63 index 6c43dfda01d4..078f5ec38de3 100644
  64 --- a/drivers/mtd/nand/ecc.c
  65 +++ b/drivers/mtd/nand/ecc.c
  66 @@ -96,6 +96,12 @@
  67  #include <linux/module.h>
  68  #include <linux/mtd/nand.h>
  69  #include <linux/slab.h>
  70 +#include <linux/of.h>
  71 +#include <linux/of_device.h>
  72 +#include <linux/of_platform.h>
  73 +
  74 +static LIST_HEAD(on_host_hw_engines);
  75 +static DEFINE_MUTEX(on_host_hw_engines_mutex);
  76
  77  /**
  78   * nand_ecc_init_ctx - Init the ECC engine context
  79 @@ -611,6 +617,88 @@ struct nand_ecc_engine *nand_ecc_get_on_die_hw_engine(struct nand_device *nand)
  80  }
  81  EXPORT_SYMBOL(nand_ecc_get_on_die_hw_engine);
  82
  83 +int nand_ecc_register_on_host_hw_engine(struct nand_ecc_engine *engine)
  84 +{
  85 +       struct nand_ecc_engine *item;
  86 +
  87 +       if (!engine)
  88 +               return -EINVAL;
  89 +
  90 +       /* Prevent multiple registrations of one engine */
  91 +       list_for_each_entry(item, &on_host_hw_engines, node)
  92 +               if (item == engine)
  93 +                       return 0;
  94 +
  95 +       mutex_lock(&on_host_hw_engines_mutex);
  96 +       list_add_tail(&engine->node, &on_host_hw_engines);
  97 +       mutex_unlock(&on_host_hw_engines_mutex);
  98 +
  99 +       return 0;
 100 +}
 101 +EXPORT_SYMBOL(nand_ecc_register_on_host_hw_engine);
 102 +
 103 +int nand_ecc_unregister_on_host_hw_engine(struct nand_ecc_engine *engine)
 104 +{
 105 +       if (!engine)
 106 +               return -EINVAL;
 107 +
 108 +       mutex_lock(&on_host_hw_engines_mutex);
 109 +       list_del(&engine->node);
 110 +       mutex_unlock(&on_host_hw_engines_mutex);
 111 +
 112 +       return 0;
 113 +}
 114 +EXPORT_SYMBOL(nand_ecc_unregister_on_host_hw_engine);
 115 +
 116 +static struct nand_ecc_engine *nand_ecc_match_on_host_hw_engine(struct device *dev)
 117 +{
 118 +       struct nand_ecc_engine *item;
 119 +
 120 +       list_for_each_entry(item, &on_host_hw_engines, node)
 121 +               if (item->dev == dev)
 122 +                       return item;
 123 +
 124 +       return NULL;
 125 +}
 126 +
 127 +struct nand_ecc_engine *nand_ecc_get_on_host_hw_engine(struct nand_device *nand)
 128 +{
 129 +       struct nand_ecc_engine *engine = NULL;
 130 +       struct device *dev = &nand->mtd.dev;
 131 +       struct platform_device *pdev;
 132 +       struct device_node *np;
 133 +
 134 +       if (list_empty(&on_host_hw_engines))
 135 +               return NULL;
 136 +
 137 +       /* Check for an explicit nand-ecc-engine property */
 138 +       np = of_parse_phandle(dev->of_node, "nand-ecc-engine", 0);
 139 +       if (np) {
 140 +               pdev = of_find_device_by_node(np);
 141 +               if (!pdev)
 142 +                       return ERR_PTR(-EPROBE_DEFER);
 143 +
 144 +               engine = nand_ecc_match_on_host_hw_engine(&pdev->dev);
 145 +               platform_device_put(pdev);
 146 +               of_node_put(np);
 147 +
 148 +               if (!engine)
 149 +                       return ERR_PTR(-EPROBE_DEFER);
 150 +       }
 151 +
 152 +       if (engine)
 153 +               get_device(engine->dev);
 154 +
 155 +       return engine;
 156 +}
 157 +EXPORT_SYMBOL(nand_ecc_get_on_host_hw_engine);
 158 +
 159 +void nand_ecc_put_on_host_hw_engine(struct nand_device *nand)
 160 +{
 161 +       put_device(nand->ecc.engine->dev);
 162 +}
 163 +EXPORT_SYMBOL(nand_ecc_put_on_host_hw_engine);
 164 +
 165  MODULE_LICENSE("GPL");
 166  MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com>");
 167  MODULE_DESCRIPTION("Generic ECC engine");
 168 diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
 169 index 32fc7edf65b3..4ddd20fe9c9e 100644
 170 --- a/include/linux/mtd/nand.h
 171 +++ b/include/linux/mtd/nand.h
 172 @@ -263,12 +263,36 @@ struct nand_ecc_engine_ops {
 173                              struct nand_page_io_req *req);
 174  };
 175
 176 +/**
 177 + * enum nand_ecc_engine_integration - How the NAND ECC engine is integrated
 178 + * @NAND_ECC_ENGINE_INTEGRATION_INVALID: Invalid value
 179 + * @NAND_ECC_ENGINE_INTEGRATION_PIPELINED: Pipelined engine, performs on-the-fly
 180 + *                                         correction, does not need to copy
 181 + *                                         data around
 182 + * @NAND_ECC_ENGINE_INTEGRATION_EXTERNAL: External engine, needs to bring the
 183 + *                                        data into its own area before use
 184 + */
 185 +enum nand_ecc_engine_integration {
 186 +       NAND_ECC_ENGINE_INTEGRATION_INVALID,
 187 +       NAND_ECC_ENGINE_INTEGRATION_PIPELINED,
 188 +       NAND_ECC_ENGINE_INTEGRATION_EXTERNAL,
 189 +};
 190 +
 191  /**
 192   * struct nand_ecc_engine - ECC engine abstraction for NAND devices
 193 + * @dev: Host device
 194 + * @node: Private field for registration time
 195   * @ops: ECC engine operations
 196 + * @integration: How the engine is integrated with the host
 197 + *               (only relevant on %NAND_ECC_ENGINE_TYPE_ON_HOST engines)
 198 + * @priv: Private data
 199   */
 200  struct nand_ecc_engine {
 201 +       struct device *dev;
 202 +       struct list_head node;
 203         struct nand_ecc_engine_ops *ops;
 204 +       enum nand_ecc_engine_integration integration;
 205 +       void *priv;
 206  };
 207
 208  void of_get_nand_ecc_user_config(struct nand_device *nand);
 209 @@ -279,8 +303,12 @@ int nand_ecc_prepare_io_req(struct nand_device *nand,
 210  int nand_ecc_finish_io_req(struct nand_device *nand,
 211                            struct nand_page_io_req *req);
 212  bool nand_ecc_is_strong_enough(struct nand_device *nand);
 213 +int nand_ecc_register_on_host_hw_engine(struct nand_ecc_engine *engine);
 214 +int nand_ecc_unregister_on_host_hw_engine(struct nand_ecc_engine *engine);
 215  struct nand_ecc_engine *nand_ecc_get_sw_engine(struct nand_device *nand);
 216  struct nand_ecc_engine *nand_ecc_get_on_die_hw_engine(struct nand_device *nand);
 217 +struct nand_ecc_engine *nand_ecc_get_on_host_hw_engine(struct nand_device *nand);
 218 +void nand_ecc_put_on_host_hw_engine(struct nand_device *nand);
 219
 220  #if IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING)
 221  struct nand_ecc_engine *nand_ecc_sw_hamming_get_engine(void);
 222 --
 223 2.35.1
 224