[PATCH] mmc: arm_pl180: Limit data transfer to U16_MAX

cmax
2024-02-27T21:02:20Z

From: max <cmax@mailbox.org>

Currently fetching files bigger that cause a data transfer greater than
U16_MAX fails.

The reason is that the specification defines the datalength register
as a 16 bit wide register, but in u-boot it is used as if it is an
32 bit register. Therefore values greater than U16_MAX cause an
infinite loop inside u-boot. U-boot expects to get more data from
interface/hardware then it will ever get and therefore inifintely waits
for more data that will never come.

Signed-off-by: max <cmax@mailbox.org>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
---
drivers/mmc/arm_pl180_mmci.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/drivers/mmc/arm_pl180_mmci.c b/drivers/mmc/arm_pl180_mmci.c
index 5cf5502ed5..af2f9a5a84 100644
--- a/drivers/mmc/arm_pl180_mmci.c
+++ b/drivers/mmc/arm_pl180_mmci.c
@@ -231,6 +231,7 @@ static int do_data_transfer(struct mmc *dev,
u32 blksz = 0;
u32 data_ctrl = 0;
u32 data_len = (u32) (data->blocks * data->blocksize);
+ assert(data_len < U16_MAX); // should be ensured by arm_pl180_get_b_max

if (!host->version2) {
blksz = (ffs(data->blocksize) - 1);
@@ -358,6 +359,14 @@ static int host_set_ios(struct mmc *dev)
return 0;
}

+static int arm_pl180_get_b_max(struct udevice *dev, void *dst, lbaint_t blkcnt)
+{
+ struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
+ struct mmc *mmc = upriv->mmc;
+
+ return U16_MAX / mmc->read_bl_len;
+}
+
#ifndef CONFIG_DM_MMC
/* MMC uses open drain drivers in the enumeration phase */
static int mmc_host_reset(struct mmc *dev)
@@ -373,6 +382,7 @@ static const struct mmc_ops arm_pl180_mmci_ops = {
.send_cmd = host_request,
.set_ios = host_set_ios,
.init = mmc_host_reset,
+ .get_b_max = arm_pl180_get_b_max,
};

/*
@@ -531,6 +541,7 @@ static const struct dm_mmc_ops arm_pl180_dm_mmc_ops = {
.send_cmd = dm_host_request,
.set_ios = dm_host_set_ios,
.get_cd = dm_mmc_getcd,
+ .get_b_max = arm_pl180_get_b_max,
};

static int arm_pl180_mmc_of_to_plat(struct udevice *dev)
--
2.43.0