openwrt/target/linux/mediatek/patches-5.15/120-09-v5.18-mtd-spinand-Create-direct-mapping-descriptors-for-EC.patch

From eb4a2d282c3c5752211d69be6dff2674119e5583 Mon Sep 17 00:00:00 2001
From: Miquel Raynal <miquel.raynal@bootlin.com>
Date: Thu, 27 Jan 2022 10:18:03 +0100
Subject: [PATCH 09/15] mtd: spinand: Create direct mapping descriptors for ECC
 operations

In order for pipelined ECC engines to be able to enable/disable the ECC
engine only when needed and avoid races when future parallel-operations
will be supported, we need to provide the information about the use of
the ECC engine in the direct mapping hooks. As direct mapping
configurations are meant to be static, it is best to create two new
mappings: one for regular 'raw' accesses and one for accesses involving
correction. It is up to the driver to use or not the new ECC enable
boolean contained in the spi-mem operation.

As dirmaps are not free (they consume a few pages of MMIO address space)
and because these extra entries are only meant to be used by pipelined
engines, let's limit their use to this specific type of engine and save
a bit of memory with all the other setups.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://lore.kernel.org/linux-mtd/20220127091808.1043392-9-miquel.raynal@bootlin.com
(cherry picked from commit f9d7c7265bcff7d9a17425a8cddf702e8fe159c2)
---
 drivers/mtd/nand/spi/core.c | 35 +++++++++++++++++++++++++++++++++--
 include/linux/mtd/spinand.h |  2 ++
 2 files changed, 35 insertions(+), 2 deletions(-)

--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -381,7 +381,10 @@ static int spinand_read_from_cache_op(st
 		}
 	}
 
-	rdesc = spinand->dirmaps[req->pos.plane].rdesc;
+	if (req->mode == MTD_OPS_RAW)
+		rdesc = spinand->dirmaps[req->pos.plane].rdesc;
+	else
+		rdesc = spinand->dirmaps[req->pos.plane].rdesc_ecc;
 
 	while (nbytes) {
 		ret = spi_mem_dirmap_read(rdesc, column, nbytes, buf);
@@ -452,7 +455,10 @@ static int spinand_write_to_cache_op(str
 			       req->ooblen);
 	}
 
-	wdesc = spinand->dirmaps[req->pos.plane].wdesc;
+	if (req->mode == MTD_OPS_RAW)
+		wdesc = spinand->dirmaps[req->pos.plane].wdesc;
+	else
+		wdesc = spinand->dirmaps[req->pos.plane].wdesc_ecc;
 
 	while (nbytes) {
 		ret = spi_mem_dirmap_write(wdesc, column, nbytes, buf);
@@ -865,6 +871,31 @@ static int spinand_create_dirmap(struct
 
 	spinand->dirmaps[plane].rdesc = desc;
 
+	if (nand->ecc.engine->integration != NAND_ECC_ENGINE_INTEGRATION_PIPELINED) {
+		spinand->dirmaps[plane].wdesc_ecc = spinand->dirmaps[plane].wdesc;
+		spinand->dirmaps[plane].rdesc_ecc = spinand->dirmaps[plane].rdesc;
+
+		return 0;
+	}
+
+	info.op_tmpl = *spinand->op_templates.update_cache;
+	info.op_tmpl.data.ecc = true;
+	desc = devm_spi_mem_dirmap_create(&spinand->spimem->spi->dev,
+					  spinand->spimem, &info);
+	if (IS_ERR(desc))
+		return PTR_ERR(desc);
+
+	spinand->dirmaps[plane].wdesc_ecc = desc;
+
+	info.op_tmpl = *spinand->op_templates.read_cache;
+	info.op_tmpl.data.ecc = true;
+	desc = devm_spi_mem_dirmap_create(&spinand->spimem->spi->dev,
+					  spinand->spimem, &info);
+	if (IS_ERR(desc))
+		return PTR_ERR(desc);
+
+	spinand->dirmaps[plane].rdesc_ecc = desc;
+
 	return 0;
 }
 
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -392,6 +392,8 @@ struct spinand_info {
 struct spinand_dirmap {
 	struct spi_mem_dirmap_desc *wdesc;
 	struct spi_mem_dirmap_desc *rdesc;
+	struct spi_mem_dirmap_desc *wdesc_ecc;
+	struct spi_mem_dirmap_desc *rdesc_ecc;
 };
 
 /**