[PATCH 06/14] mmc: omap: handle highmem pages

Christoph Hellwig
2019-02-12T07:25:20Z

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/mmc/host/omap.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/host/omap.c b/drivers/mmc/host/omap.c
index c60a7625b1fa..6741c95f2281 100644
--- a/drivers/mmc/host/omap.c
+++ b/drivers/mmc/host/omap.c
@@ -148,7 +148,7 @@ struct mmc_omap_host {

unsigned int sg_len;
int sg_idx;
- u16 * buffer;
+ u32 buffer_offset;
u32 buffer_bytes_left;
u32 total_bytes_left;

@@ -649,7 +649,7 @@ mmc_omap_sg_to_buf(struct mmc_omap_host *host)

sg = host->data->sg + host->sg_idx;
host->buffer_bytes_left = sg->length;
- host->buffer = sg_virt(sg);
+ host->buffer_offset = sg->offset;
if (host->buffer_bytes_left > host->total_bytes_left)
host->buffer_bytes_left = host->total_bytes_left;
}
@@ -666,7 +666,9 @@ mmc_omap_clk_timer(struct timer_list *t)
static void
mmc_omap_xfer_data(struct mmc_omap_host *host, int write)
{
+ struct scatterlist *sg = host->data->sg + host->sg_idx;
int n, nwords;
+ void *p;

if (host->buffer_bytes_left == 0) {
host->sg_idx++;
@@ -684,15 +686,17 @@ mmc_omap_xfer_data(struct mmc_omap_host *host, int write)
host->total_bytes_left -= n;
host->data->bytes_xfered += n;

+ p = sg_kmap_atomic(sg);
if (write) {
__raw_writesw(host->virt_base + OMAP_MMC_REG(host, DATA),
- host->buffer, nwords);
+ p + host->buffer_offset, nwords);
} else {
__raw_readsw(host->virt_base + OMAP_MMC_REG(host, DATA),
- host->buffer, nwords);
+ p + host->buffer_offset, nwords);
}
+ sg_kunmap_atomic(sg, p);

- host->buffer += nwords;
+ host->buffer_offset += nwords;
}

#ifdef CONFIG_MMC_DEBUG
@@ -1250,6 +1254,7 @@ static int mmc_omap_new_slot(struct mmc_omap_host *host, int id)
mmc->caps |= MMC_CAP_4_BIT_DATA | MMC_CAP_ERASE;

mmc->ops = &mmc_omap_ops;
+ mmc->need_kmap = 1;
mmc->f_min = 400000;

if (mmc_omap2())
--
2.20.1