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mtd: gpmi: set the BCH's geometry with the ecc info
If the nand chip provides us the ECC info, we can use it firstly. The set_geometry_by_ecc_info() will use the ECC info, and calculate the parameters we need. Rename the old code to legacy_set_geometry() which will takes effect when there is no ECC info from the nand chip or we fails in the ECC info case. Signed-off-by: Huang Shijie <b32955@freescale.com> Signed-off-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Huang Shijie
David Woodhouse
parent
d1048aaf6d
commit
2febcdf84b
@ -111,7 +111,132 @@ static inline bool gpmi_check_ecc(struct gpmi_nand_data *this)
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return true;
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}
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int common_nfc_set_geometry(struct gpmi_nand_data *this)
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/*
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* If we can get the ECC information from the nand chip, we do not
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* need to calculate them ourselves.
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*
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* We may have available oob space in this case.
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*/
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static bool set_geometry_by_ecc_info(struct gpmi_nand_data *this)
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{
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struct bch_geometry *geo = &this->bch_geometry;
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struct mtd_info *mtd = &this->mtd;
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struct nand_chip *chip = mtd->priv;
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struct nand_oobfree *of = gpmi_hw_ecclayout.oobfree;
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unsigned int block_mark_bit_offset;
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if (!(chip->ecc_strength_ds > 0 && chip->ecc_step_ds > 0))
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return false;
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switch (chip->ecc_step_ds) {
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case SZ_512:
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geo->gf_len = 13;
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break;
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case SZ_1K:
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geo->gf_len = 14;
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break;
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default:
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dev_err(this->dev,
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"unsupported nand chip. ecc bits : %d, ecc size : %d\n",
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chip->ecc_strength_ds, chip->ecc_step_ds);
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return false;
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}
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geo->ecc_chunk_size = chip->ecc_step_ds;
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geo->ecc_strength = round_up(chip->ecc_strength_ds, 2);
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if (!gpmi_check_ecc(this))
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return false;
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/* Keep the C >= O */
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if (geo->ecc_chunk_size < mtd->oobsize) {
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dev_err(this->dev,
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"unsupported nand chip. ecc size: %d, oob size : %d\n",
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chip->ecc_step_ds, mtd->oobsize);
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return false;
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}
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/* The default value, see comment in the legacy_set_geometry(). */
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geo->metadata_size = 10;
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geo->ecc_chunk_count = mtd->writesize / geo->ecc_chunk_size;
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/*
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* Now, the NAND chip with 2K page(data chunk is 512byte) shows below:
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*
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* | P |
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* |<----------------------------------------------------->|
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* | |
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* | (Block Mark) |
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* | P' | | | |
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* |<-------------------------------------------->| D | | O' |
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* | |<---->| |<--->|
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* V V V V V
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* +---+----------+-+----------+-+----------+-+----------+-+-----+
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* | M | data |E| data |E| data |E| data |E| |
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* +---+----------+-+----------+-+----------+-+----------+-+-----+
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* ^ ^
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* | O |
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* |<------------>|
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* | |
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*
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* P : the page size for BCH module.
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* E : The ECC strength.
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* G : the length of Galois Field.
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* N : The chunk count of per page.
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* M : the metasize of per page.
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* C : the ecc chunk size, aka the "data" above.
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* P': the nand chip's page size.
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* O : the nand chip's oob size.
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* O': the free oob.
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*
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* The formula for P is :
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*
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* E * G * N
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* P = ------------ + P' + M
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* 8
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*
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* The position of block mark moves forward in the ECC-based view
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* of page, and the delta is:
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*
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* E * G * (N - 1)
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* D = (---------------- + M)
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* 8
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*
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* Please see the comment in legacy_set_geometry().
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* With the condition C >= O , we still can get same result.
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* So the bit position of the physical block mark within the ECC-based
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* view of the page is :
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* (P' - D) * 8
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*/
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geo->page_size = mtd->writesize + geo->metadata_size +
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(geo->gf_len * geo->ecc_strength * geo->ecc_chunk_count) / 8;
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/* The available oob size we have. */
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if (geo->page_size < mtd->writesize + mtd->oobsize) {
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of->offset = geo->page_size - mtd->writesize;
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of->length = mtd->oobsize - of->offset;
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mtd->oobavail = gpmi_hw_ecclayout.oobavail = of->length;
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}
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geo->payload_size = mtd->writesize;
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geo->auxiliary_status_offset = ALIGN(geo->metadata_size, 4);
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geo->auxiliary_size = ALIGN(geo->metadata_size, 4)
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+ ALIGN(geo->ecc_chunk_count, 4);
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if (!this->swap_block_mark)
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return true;
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/* For bit swap. */
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block_mark_bit_offset = mtd->writesize * 8 -
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(geo->ecc_strength * geo->gf_len * (geo->ecc_chunk_count - 1)
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+ geo->metadata_size * 8);
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geo->block_mark_byte_offset = block_mark_bit_offset / 8;
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geo->block_mark_bit_offset = block_mark_bit_offset % 8;
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return true;
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}
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static int legacy_set_geometry(struct gpmi_nand_data *this)
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{
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struct bch_geometry *geo = &this->bch_geometry;
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struct mtd_info *mtd = &this->mtd;
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@ -223,6 +348,11 @@ int common_nfc_set_geometry(struct gpmi_nand_data *this)
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return 0;
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}
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int common_nfc_set_geometry(struct gpmi_nand_data *this)
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{
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return set_geometry_by_ecc_info(this) ? 0 : legacy_set_geometry(this);
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}
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struct dma_chan *get_dma_chan(struct gpmi_nand_data *this)
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{
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int chipnr = this->current_chip;
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