[PATCH 06/11] mmc: s3cmci: handle chained sglists

From: Christoph Hellwig
Date: Mon Jan 14 2019 - 04:59:28 EST


Use the proper sg_next() helper to move to the next scatterlist element
to support chained scatterlists.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/mmc/host/s3cmci.c | 19 +++++++++----------
drivers/mmc/host/s3cmci.h | 2 +-
2 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/mmc/host/s3cmci.c b/drivers/mmc/host/s3cmci.c
index 1be84426c817..2660fb61d1d0 100644
--- a/drivers/mmc/host/s3cmci.c
+++ b/drivers/mmc/host/s3cmci.c
@@ -320,20 +320,19 @@ static void s3cmci_check_sdio_irq(struct s3cmci_host *host)

static inline int get_data_buffer(struct s3cmci_host *host)
{
- if (host->pio_sgptr >= host->mrq->data->sg_len) {
- dbg(host, dbg_debug, "no more buffers (%i/%i)\n",
- host->pio_sgptr, host->mrq->data->sg_len);
+ if (!host->next_sg) {
+ dbg(host, dbg_debug, "no more buffers (%i)\n",
+ host->mrq->data->sg_len);
return -EBUSY;
}
- host->cur_sg = &host->mrq->data->sg[host->pio_sgptr];
+ host->cur_sg = host->next_sg;
+ host->next_sg = sg_next(host->next_sg);

host->pio_bytes = host->cur_sg->length;
host->pio_offset = host->cur_sg->offset;

- host->pio_sgptr++;
-
- dbg(host, dbg_sg, "new buffer (%i/%i)\n",
- host->pio_sgptr, host->mrq->data->sg_len);
+ dbg(host, dbg_sg, "new buffer (%i)\n",
+ host->mrq->data->sg_len);

return 0;
}
@@ -1052,8 +1051,8 @@ static int s3cmci_prepare_pio(struct s3cmci_host *host, struct mmc_data *data)

BUG_ON((data->flags & BOTH_DIR) == BOTH_DIR);

- host->pio_sgptr = 0;
- host->cur_sg = &host->mrq->data->sg[host->pio_sgptr];
+ host->cur_sg = host->mrq->data->sg;
+ host->next_sg = sg_next(host->cur_sg);
host->pio_bytes = 0;
host->pio_count = 0;
host->pio_active = rw ? XFER_WRITE : XFER_READ;
diff --git a/drivers/mmc/host/s3cmci.h b/drivers/mmc/host/s3cmci.h
index 4320f7d832dc..caf1078d07d1 100644
--- a/drivers/mmc/host/s3cmci.h
+++ b/drivers/mmc/host/s3cmci.h
@@ -51,7 +51,7 @@ struct s3cmci_host {
int dma_complete;

struct scatterlist *cur_sg;
- u32 pio_sgptr;
+ struct scatterlist *next_sg;
u32 pio_bytes;
u32 pio_count;
u32 pio_offset;
--
2.20.1