spl: nand: Set bl_len to page size

Since commit 34793598c83 ("mtd: nand: mxs_nand_spl: Remove the page aligned
access") there are no longer any users of nand_get_mtd. However, it is
still important to know what the page size is so we can allocate a
large-enough buffer. If the image size is not page-aligned, we will go off
the end of the buffer and clobber some memory.

Introduce a new function nand_page_size which returns the page size. For
most drivers it is easy to determine the page size. However, a few need to
be modified since they only keep the page size around temporarily.

It's possible that this patch could cause a regression on some platforms if
the offset is non-aligned and there is invalid address space immediately
before the load address. spl_load_legacy_img does not (except when
compressing) respect bl_len, so only boards with SPL_LOAD_FIT (8 boards) or
SPL_LOAD_IMX_CONTAINER (none in tree) would be affected.

defconfig               CONFIG_TEXT_BASE
======================= ================
am335x_evm              0x80800000
am43xx_evm              0x80800000
am43xx_evm_rtconly      0x80800000
am43xx_evm_usbhost_boot 0x80800000
am43xx_hs_evm           0x80800000
dra7xx_evm              0x80800000
gwventana_nand          0x17800000
imx8mn_bsh_smm_s2       0x40200000

All the sitara boards have DDR mapped at 0x80000000. gwventana is an i.MX6Q
which has DDR at 0x10000000. I don't have the IMX8MNRM handy, but on the
i.MX8M DDR starts at 0x40000000. Therefore all of these boards can handle a
little underflow.

Signed-off-by: Sean Anderson <seanga2@gmail.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/mtd/nand/raw/fsl_ifc_spl.c b/drivers/mtd/nand/raw/fsl_ifc_spl.c
index c67065e..69d26f1 100644
--- a/drivers/mtd/nand/raw/fsl_ifc_spl.c
+++ b/drivers/mtd/nand/raw/fsl_ifc_spl.c
@@ -106,6 +106,8 @@ static inline int bad_block(uchar *marker, int port_size)
 		return __raw_readw((u16 *)marker) != 0xffff;
 }
 
+static int saved_page_size;
+
 int nand_spl_load_image(uint32_t offs, unsigned int uboot_size, void *vdst)
 {
 	struct fsl_ifc_fcm *gregs = (void *)CFG_SYS_IFC_ADDR;
@@ -150,6 +152,7 @@ int nand_spl_load_image(uint32_t offs, unsigned int uboot_size, void *vdst)
 		if (port_size == 8)
 			bad_marker = 5;
 	}
+	saved_page_size = page_size;
 
 	ver = ifc_in32(&gregs->ifc_rev);
 	if (ver >= FSL_IFC_V2_0_0)
@@ -302,6 +305,11 @@ void nand_init(void)
 {
 }
 
+unsigned int nand_page_size(void)
+{
+	return saved_page_size;
+}
+
 void nand_deselect(void)
 {
 }