[PATCH 05/14] mmc: moxart: handle highmem pages

Christoph Hellwig
2019-02-12T07:25:19Z

Instead of setting up a kernel pointer to track the current PIO address,
track the offset in the current page, and do a kmap for the page while
doing the actual PIO operations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/mmc/host/moxart-mmc.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/host/moxart-mmc.c b/drivers/mmc/host/moxart-mmc.c
index a0670e9cd012..116964e6506d 100644
--- a/drivers/mmc/host/moxart-mmc.c
+++ b/drivers/mmc/host/moxart-mmc.c
@@ -311,7 +311,7 @@ static void moxart_transfer_pio(struct moxart_host *host)
if (host->data_len == data->bytes_xfered)
return;

- sgp = sg_virt(host->cur_sg);
+ sgp = kmap(sg_page(host->cur_sg)) + host->cur_sg->offset;
remain = host->data_remain;

if (data->flags & MMC_DATA_WRITE) {
@@ -319,8 +319,7 @@ static void moxart_transfer_pio(struct moxart_host *host)
if (moxart_wait_for_status(host, FIFO_URUN, &status)
== -ETIMEDOUT) {
data->error = -ETIMEDOUT;
- complete(&host->pio_complete);
- return;
+ goto done;
}
for (len = 0; len < remain && len < host->fifo_width;) {
iowrite32(*sgp, host->base + REG_DATA_WINDOW);
@@ -335,8 +334,7 @@ static void moxart_transfer_pio(struct moxart_host *host)
if (moxart_wait_for_status(host, FIFO_ORUN, &status)
== -ETIMEDOUT) {
data->error = -ETIMEDOUT;
- complete(&host->pio_complete);
- return;
+ goto done;
}
for (len = 0; len < remain && len < host->fifo_width;) {
/* SCR data must be read in big endian. */
@@ -356,10 +354,15 @@ static void moxart_transfer_pio(struct moxart_host *host)
data->bytes_xfered += host->data_remain - remain;
host->data_remain = remain;

- if (host->data_len != data->bytes_xfered)
+ if (host->data_len != data->bytes_xfered) {
+ kunmap(sg_page(host->cur_sg));
moxart_next_sg(host);
- else
- complete(&host->pio_complete);
+ return;
+ }
+
+done:
+ kunmap(sg_page(host->cur_sg));
+ complete(&host->pio_complete);
}

static void moxart_prepare_data(struct moxart_host *host)
@@ -614,6 +617,7 @@ static int moxart_probe(struct platform_device *pdev)
spin_lock_init(&host->lock);

mmc->ops = &moxart_ops;
+ mmc->need_kmap = 1;
mmc->f_max = DIV_ROUND_CLOSEST(host->sysclk, 2);
mmc->f_min = DIV_ROUND_CLOSEST(host->sysclk, CLK_DIV_MASK * 2);
mmc->ocr_avail = 0xffff00; /* Support 2.0v - 3.6v power. */
--
2.20.1