mmc: tmio: Fix PIO mode with CONFIG_HIGHMEM

Current PIO mode occurred kernel panic with CONFIG_HIGHMEM. This patch fixes the kernel panic by converting the driver to the sg_miter API.

Reported-by Cao Minh Hiep <[email protected]>

Signed-off-by Keita Kobayashi <[email protected]>

---
This patch is based on renesas.git / renesas-devel-20150211-v3.19 tag.

 drivers/mmc/host/tmio_mmc.h     |    1 +
 drivers/mmc/host/tmio_mmc_pio.c |   35 ++++++++++++++++-------------------
 2 files changed, 17 insertions(+), 19 deletions(-)

drivers/mmc/host/tmio_mmc.h +1 -0

index a34ecbe..3092219 100644
@@ -56,6 +56,7 @@ struct tmio_mmc_host {
        struct scatterlist      *sg_orig;
        unsigned int            sg_len;
        unsigned int            sg_off;
+       struct sg_mapping_iter  sg_miter;
 
        struct platform_device *pdev;
        struct tmio_mmc_data *pdata;

drivers/mmc/host/tmio_mmc_pio.c +16 -20

index 250bf8c..6d8f363 100644
@@ -70,17 +70,14 @@ static void tmio_mmc_ack_mmc_irqs(struct tmio_mmc_host *host, u32 i)
 
 static void tmio_mmc_init_sg(struct tmio_mmc_host *host, struct mmc_data *data)
 {
-       host->sg_len = data->sg_len;
-       host->sg_ptr = data->sg;
-       host->sg_orig = data->sg;
-       host->sg_off = 0;
-}
+       unsigned int flags = SG_MITER_ATOMIC;
 
-static int tmio_mmc_next_sg(struct tmio_mmc_host *host)
-{
-       host->sg_ptr = sg_next(host->sg_ptr);
-       host->sg_off = 0;
-       return --host->sg_len;
+       if (data->flags & MMC_DATA_READ)
+               flags |= SG_MITER_TO_SG;
+       else
+               flags |= SG_MITER_FROM_SG;
+
+       sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
 }
 
 #ifdef CONFIG_MMC_DEBUG

@@ -418,7 +415,7 @@ static void tmio_mmc_transfer_data(struct tmio_mmc_host *host,
 static void tmio_mmc_pio_irq(struct tmio_mmc_host *host)
 {
        struct mmc_data *data = host->data;
-       void *sg_virt;
+       struct sg_mapping_iter *sg_miter = &host->sg_miter;
        unsigned short *buf;
        unsigned int count;
        unsigned long flags;

@@ -431,10 +428,12 @@ static void tmio_mmc_pio_irq(struct tmio_mmc_host *host)
                return;
        }
 
-       sg_virt = tmio_mmc_kmap_atomic(host->sg_ptr, &flags);
-       buf = (unsigned short *)(sg_virt + host->sg_off);
+       local_irq_save(flags);
 
-       count = host->sg_ptr->length - host->sg_off;
+       if (!sg_miter_next(sg_miter))
+               return;
+       buf = sg_miter->addr;
+       count = sg_miter->length;
        if (count > data->blksz)
                count = data->blksz;
 

@@ -444,12 +443,10 @@ static void tmio_mmc_pio_irq(struct tmio_mmc_host *host)
        /* Transfer the data */
        tmio_mmc_transfer_data(host, buf, count);
 
-       host->sg_off += count;
-
-       tmio_mmc_kunmap_atomic(host->sg_ptr, &flags, sg_virt);
+       sg_miter->consumed = count;
+       sg_miter_stop(sg_miter);
 
-       if (host->sg_off == host->sg_ptr->length)
-               tmio_mmc_next_sg(host);
+       local_irq_restore(flags);
 
        return;
 }
--

1.7.9.5
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