mtd: nand: Only allocate ecc->{calc, code}_buf when actually needed

The only users of the ecc->{calc,code}_buf buffers are NAND controller
drivers implementing ecc->calculate() and/or ecc->correct(). Since the
->oobsize can be non-negligle, especially on modern NAND devices, we'd
better allocate it only when it is actually required.

Make ecc->{calc,code}_buf allocation dependent on the presence of
ecc->calculate() or ecc->correct().

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 32c0239b380a812043bee4b109854122c6fbb39e..84d0a5d67e338e9b03b514e82248878502154508 100644 (file)
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -5318,21 +5318,9 @@ int nand_scan_tail(struct mtd_info *mtd)
                return -EINVAL;
        }
 
-       ecc->calc_buf = kmalloc(mtd->oobsize, GFP_KERNEL);
-       if (!ecc->calc_buf)
-               return -ENOMEM;
-
-       ecc->code_buf = kmalloc(mtd->oobsize, GFP_KERNEL);
-       if (!ecc->code_buf) {
-               ret = -ENOMEM;
-               goto err_free_buf;
-       }
-
        chip->data_buf = kmalloc(mtd->writesize + mtd->oobsize, GFP_KERNEL);
-       if (!chip->data_buf) {
-               ret = -ENOMEM;
-               goto err_free_buf;
-       }
+       if (!chip->data_buf)
+               return -ENOMEM;
 
        /*
         * FIXME: some NAND manufacturer drivers expect the first die to be
@@ -5495,6 +5483,15 @@ int nand_scan_tail(struct mtd_info *mtd)
                goto err_nand_manuf_cleanup;
        }
 
+       if (ecc->correct || ecc->calculate) {
+               ecc->calc_buf = kmalloc(mtd->oobsize, GFP_KERNEL);
+               ecc->code_buf = kmalloc(mtd->oobsize, GFP_KERNEL);
+               if (!ecc->calc_buf || !ecc->code_buf) {
+                       ret = -ENOMEM;
+                       goto err_nand_manuf_cleanup;
+               }
+       }
+
        /* For many systems, the standard OOB write also works for raw */
        if (!ecc->read_oob_raw)
                ecc->read_oob_raw = ecc->read_oob;