#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/mtd/nand.h>
#include <linux/mtd/nand-ecc-sw-hamming.h>
+#include <linux/slab.h>
#include <asm/byteorder.h>
/*
}
EXPORT_SYMBOL(nand_ecc_sw_hamming_correct);
+int nand_ecc_sw_hamming_init_ctx(struct nand_device *nand)
+{
+ struct nand_ecc_props *conf = &nand->ecc.ctx.conf;
+ struct nand_ecc_sw_hamming_conf *engine_conf;
+ struct mtd_info *mtd = nanddev_to_mtd(nand);
+ int ret;
+
+ if (!mtd->ooblayout) {
+ switch (mtd->oobsize) {
+ case 8:
+ case 16:
+ mtd_set_ooblayout(mtd, nand_get_small_page_ooblayout());
+ break;
+ case 64:
+ case 128:
+ mtd_set_ooblayout(mtd,
+ nand_get_large_page_hamming_ooblayout());
+ break;
+ default:
+ return -ENOTSUPP;
+ }
+ }
+
+ conf->engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
+ conf->algo = NAND_ECC_ALGO_HAMMING;
+ conf->step_size = nand->ecc.user_conf.step_size;
+ conf->strength = 1;
+
+ /* Use the strongest configuration by default */
+ if (conf->step_size != 256 && conf->step_size != 512)
+ conf->step_size = 256;
+
+ engine_conf = kzalloc(sizeof(*engine_conf), GFP_KERNEL);
+ if (!engine_conf)
+ return -ENOMEM;
+
+ ret = nand_ecc_init_req_tweaking(&engine_conf->req_ctx, nand);
+ if (ret)
+ goto free_engine_conf;
+
+ engine_conf->code_size = 3;
+ engine_conf->nsteps = mtd->writesize / conf->step_size;
+ engine_conf->calc_buf = kzalloc(mtd->oobsize, GFP_KERNEL);
+ engine_conf->code_buf = kzalloc(mtd->oobsize, GFP_KERNEL);
+ if (!engine_conf->calc_buf || !engine_conf->code_buf) {
+ ret = -ENOMEM;
+ goto free_bufs;
+ }
+
+ nand->ecc.ctx.priv = engine_conf;
+ nand->ecc.ctx.total = engine_conf->nsteps * engine_conf->code_size;
+
+ return 0;
+
+free_bufs:
+ nand_ecc_cleanup_req_tweaking(&engine_conf->req_ctx);
+ kfree(engine_conf->calc_buf);
+ kfree(engine_conf->code_buf);
+free_engine_conf:
+ kfree(engine_conf);
+
+ return ret;
+}
+EXPORT_SYMBOL(nand_ecc_sw_hamming_init_ctx);
+
+void nand_ecc_sw_hamming_cleanup_ctx(struct nand_device *nand)
+{
+ struct nand_ecc_sw_hamming_conf *engine_conf = nand->ecc.ctx.priv;
+
+ if (engine_conf) {
+ nand_ecc_cleanup_req_tweaking(&engine_conf->req_ctx);
+ kfree(engine_conf->calc_buf);
+ kfree(engine_conf->code_buf);
+ kfree(engine_conf);
+ }
+}
+EXPORT_SYMBOL(nand_ecc_sw_hamming_cleanup_ctx);
+
+static int nand_ecc_sw_hamming_prepare_io_req(struct nand_device *nand,
+ struct nand_page_io_req *req)
+{
+ struct nand_ecc_sw_hamming_conf *engine_conf = nand->ecc.ctx.priv;
+ struct mtd_info *mtd = nanddev_to_mtd(nand);
+ int eccsize = nand->ecc.ctx.conf.step_size;
+ int eccbytes = engine_conf->code_size;
+ int eccsteps = engine_conf->nsteps;
+ int total = nand->ecc.ctx.total;
+ u8 *ecccalc = engine_conf->calc_buf;
+ const u8 *data;
+ int i;
+
+ /* Nothing to do for a raw operation */
+ if (req->mode == MTD_OPS_RAW)
+ return 0;
+
+ /* This engine does not provide BBM/free OOB bytes protection */
+ if (!req->datalen)
+ return 0;
+
+ nand_ecc_tweak_req(&engine_conf->req_ctx, req);
+
+ /* No more preparation for page read */
+ if (req->type == NAND_PAGE_READ)
+ return 0;
+
+ /* Preparation for page write: derive the ECC bytes and place them */
+ for (i = 0, data = req->databuf.out;
+ eccsteps;
+ eccsteps--, i += eccbytes, data += eccsize)
+ nand_ecc_sw_hamming_calculate(nand, data, &ecccalc[i]);
+
+ return mtd_ooblayout_set_eccbytes(mtd, ecccalc, (void *)req->oobbuf.out,
+ 0, total);
+}
+
+static int nand_ecc_sw_hamming_finish_io_req(struct nand_device *nand,
+ struct nand_page_io_req *req)
+{
+ struct nand_ecc_sw_hamming_conf *engine_conf = nand->ecc.ctx.priv;
+ struct mtd_info *mtd = nanddev_to_mtd(nand);
+ int eccsize = nand->ecc.ctx.conf.step_size;
+ int total = nand->ecc.ctx.total;
+ int eccbytes = engine_conf->code_size;
+ int eccsteps = engine_conf->nsteps;
+ u8 *ecccalc = engine_conf->calc_buf;
+ u8 *ecccode = engine_conf->code_buf;
+ unsigned int max_bitflips = 0;
+ u8 *data = req->databuf.in;
+ int i, ret;
+
+ /* Nothing to do for a raw operation */
+ if (req->mode == MTD_OPS_RAW)
+ return 0;
+
+ /* This engine does not provide BBM/free OOB bytes protection */
+ if (!req->datalen)
+ return 0;
+
+ /* No more preparation for page write */
+ if (req->type == NAND_PAGE_WRITE) {
+ nand_ecc_restore_req(&engine_conf->req_ctx, req);
+ return 0;
+ }
+
+ /* Finish a page read: retrieve the (raw) ECC bytes*/
+ ret = mtd_ooblayout_get_eccbytes(mtd, ecccode, req->oobbuf.in, 0,
+ total);
+ if (ret)
+ return ret;
+
+ /* Calculate the ECC bytes */
+ for (i = 0; eccsteps; eccsteps--, i += eccbytes, data += eccsize)
+ nand_ecc_sw_hamming_calculate(nand, data, &ecccalc[i]);
+
+ /* Finish a page read: compare and correct */
+ for (eccsteps = engine_conf->nsteps, i = 0, data = req->databuf.in;
+ eccsteps;
+ eccsteps--, i += eccbytes, data += eccsize) {
+ int stat = nand_ecc_sw_hamming_correct(nand, data,
+ &ecccode[i],
+ &ecccalc[i]);
+ if (stat < 0) {
+ mtd->ecc_stats.failed++;
+ } else {
+ mtd->ecc_stats.corrected += stat;
+ max_bitflips = max_t(unsigned int, max_bitflips, stat);
+ }
+ }
+
+ nand_ecc_restore_req(&engine_conf->req_ctx, req);
+
+ return max_bitflips;
+}
+
+static struct nand_ecc_engine_ops nand_ecc_sw_hamming_engine_ops = {
+ .init_ctx = nand_ecc_sw_hamming_init_ctx,
+ .cleanup_ctx = nand_ecc_sw_hamming_cleanup_ctx,
+ .prepare_io_req = nand_ecc_sw_hamming_prepare_io_req,
+ .finish_io_req = nand_ecc_sw_hamming_finish_io_req,
+};
+
+static struct nand_ecc_engine nand_ecc_sw_hamming_engine = {
+ .ops = &nand_ecc_sw_hamming_engine_ops,
+};
+
+struct nand_ecc_engine *nand_ecc_sw_hamming_get_engine(void)
+{
+ return &nand_ecc_sw_hamming_engine;
+}
+EXPORT_SYMBOL(nand_ecc_sw_hamming_get_engine);
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Frans Meulenbroeks <fransmeulenbroeks@gmail.com>");
MODULE_DESCRIPTION("NAND software Hamming ECC support");
projects / linux-2.6-microblaze.git / blobdiff