ACMD22 is used to verify the previously write operation. Normally, it
returns the number of written sectors as u32. SDUC, however, returns it
as u64. This is not a superfluous requirement, because SDUC writes may
exceeds 2TB. For Linux mmc however, the previously write operation
could not be more than the block layer limits, thus we make room for a
u64 and cast the returning value to u32.
Reviewed-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
---
drivers/mmc/core/block.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 26a67d2033f0..b4d58fde3ee5 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -50,6 +50,7 @@
#include <linux/mmc/sd.h>
#include <linux/uaccess.h>
+#include <asm/unaligned.h>
#include "queue.h"
#include "block.h"
@@ -993,11 +994,10 @@ static int mmc_sd_num_wr_blocks(struct mmc_card *card, u32 *written_blocks)
int err;
u32 result;
__be32 *blocks;
-
+ u8 resp_sz = mmc_card_ult_capacity(card) ? 8 : 4;
struct mmc_request mrq = {};
struct mmc_command cmd = {};
struct mmc_data data = {};
-
struct scatterlist sg;
err = mmc_app_cmd(card->host, card);
@@ -1008,7 +1008,7 @@ static int mmc_sd_num_wr_blocks(struct mmc_card *card, u32 *written_blocks)
cmd.arg = 0;
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
- data.blksz = 4;
+ data.blksz = resp_sz;
data.blocks = 1;
data.flags = MMC_DATA_READ;
data.sg = &sg;
@@ -1018,15 +1018,27 @@ static int mmc_sd_num_wr_blocks(struct mmc_card *card, u32 *written_blocks)
mrq.cmd = &cmd;
mrq.data = &data;
- blocks = kmalloc(4, GFP_KERNEL);
+ blocks = kmalloc(resp_sz, GFP_KERNEL);
if (!blocks)
return -ENOMEM;
- sg_init_one(&sg, blocks, 4);
+ sg_init_one(&sg, blocks, resp_sz);
mmc_wait_for_req(card->host, &mrq);
- result = ntohl(*blocks);
+ if (mmc_card_ult_capacity(card)) {
+ /*
+ * Normally, ACMD22 returns the number of written sectors as
+ * u32. SDUC, however, returns it as u64. This is not a
+ * superfluous requirement, because SDUC writes may exceed 2TB.
+ * For Linux mmc however, the previously write operation could
+ * not be more than the block layer limits, thus just make room
+ * for a u64 and cast the response back to u32.
+ */
+ result = clamp_val(get_unaligned_be64(blocks), 0, UINT_MAX);
+ } else {
+ result = ntohl(*blocks);
+ }
kfree(blocks);
if (cmd.error || data.error)
--
2.25.1
