[PATCH 10/14] mmc: mvsdio: handle highmem pages

Christoph Hellwig
2019-02-12T07:25:24Z

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/mvsdio.c | 33 +++++++++++++++++++++------------
1 file changed, 21 insertions(+), 12 deletions(-)

diff --git a/drivers/mmc/host/mvsdio.c b/drivers/mmc/host/mvsdio.c
index e22bbff89c8d..d04c78125a4d 100644
--- a/drivers/mmc/host/mvsdio.c
+++ b/drivers/mmc/host/mvsdio.c
@@ -42,7 +42,8 @@ struct mvsd_host {
unsigned int intr_en;
unsigned int ctrl;
unsigned int pio_size;
- void *pio_ptr;
+ struct scatterlist *pio_sg;
+ unsigned int pio_offset; /* offset in words into the segment */
unsigned int sg_frags;
unsigned int ns_per_clk;
unsigned int clock;
@@ -96,9 +97,9 @@ static int mvsd_setup_data(struct mvsd_host *host, struct mmc_data *data)
if (tmout_index > MVSD_HOST_CTRL_TMOUT_MAX)
tmout_index = MVSD_HOST_CTRL_TMOUT_MAX;

- dev_dbg(host->dev, "data %s at 0x%08x: blocks=%d blksz=%d tmout=%u (%d)\n",
+ dev_dbg(host->dev, "data %s at 0x%08llx: blocks=%d blksz=%d tmout=%u (%d)\n",
(data->flags & MMC_DATA_READ) ? "read" : "write",
- (u32)sg_virt(data->sg), data->blocks, data->blksz,
+ (u64)sg_phys(data->sg), data->blocks, data->blksz,
tmout, tmout_index);

host->ctrl &= ~MVSD_HOST_CTRL_TMOUT_MASK;
@@ -118,10 +119,11 @@ static int mvsd_setup_data(struct mvsd_host *host, struct mmc_data *data)
* boundary.
*/
host->pio_size = data->blocks * data->blksz;
- host->pio_ptr = sg_virt(data->sg);
+ host->pio_sg = data->sg;
+ host->pio_offset = data->sg->offset / 2;
if (!nodma)
- dev_dbg(host->dev, "fallback to PIO for data at 0x%p size %d\n",
- host->pio_ptr, host->pio_size);
+ dev_dbg(host->dev, "fallback to PIO for data at 0x%x size %d\n",
+ host->pio_offset, host->pio_size);
return 1;
} else {
dma_addr_t phys_addr;
@@ -291,8 +293,9 @@ static u32 mvsd_finish_data(struct mvsd_host *host, struct mmc_data *data,
{
void __iomem *iobase = host->base;

- if (host->pio_ptr) {
- host->pio_ptr = NULL;
+ if (host->pio_sg) {
+ host->pio_sg = NULL;
+ host->pio_offset = 0;
host->pio_size = 0;
} else {
dma_unmap_sg(mmc_dev(host->mmc), data->sg, host->sg_frags,
@@ -376,8 +379,10 @@ static irqreturn_t mvsd_irq(int irq, void *dev)
if (host->pio_size &&
(intr_status & host->intr_en &
(MVSD_NOR_RX_READY | MVSD_NOR_RX_FIFO_8W))) {
- u16 *p = host->pio_ptr;
+ u16 *base = sg_kmap_atomic(host->pio_sg);
+ u16 *p = base + host->pio_offset;
int s = host->pio_size;
+
while (s >= 32 && (intr_status & MVSD_NOR_RX_FIFO_8W)) {
readsw(iobase + MVSD_FIFO, p, 16);
p += 16;
@@ -416,13 +421,15 @@ static irqreturn_t mvsd_irq(int irq, void *dev)
}
dev_dbg(host->dev, "pio %d intr 0x%04x hw_state 0x%04x\n",
s, intr_status, mvsd_read(MVSD_HW_STATE));
- host->pio_ptr = p;
+ host->pio_offset = p - base;
host->pio_size = s;
+ sg_kunmap_atomic(host->pio_sg, base);
irq_handled = 1;
} else if (host->pio_size &&
(intr_status & host->intr_en &
(MVSD_NOR_TX_AVAIL | MVSD_NOR_TX_FIFO_8W))) {
- u16 *p = host->pio_ptr;
+ u16 *base = sg_kmap_atomic(host->pio_sg);
+ u16 *p = base + host->pio_offset;
int s = host->pio_size;
/*
* The TX_FIFO_8W bit is unreliable. When set, bursting
@@ -453,8 +460,9 @@ static irqreturn_t mvsd_irq(int irq, void *dev)
}
dev_dbg(host->dev, "pio %d intr 0x%04x hw_state 0x%04x\n",
s, intr_status, mvsd_read(MVSD_HW_STATE));
- host->pio_ptr = p;
+ host->pio_offset = p - base;
host->pio_size = s;
+ sg_kunmap_atomic(host->pio_sg, base);
irq_handled = 1;
}

@@ -737,6 +745,7 @@ static int mvsd_probe(struct platform_device *pdev)
clk_prepare_enable(host->clk);

mmc->ops = &mvsd_ops;
+ mmc->need_kmap = 1;

mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;

--
2.20.1