The mmci driver's SG list iteration logic assumes that each SG entry
spans only one page, and only maps and flushes one page of the sg. This
is not a valid assumption. Fix it by converting the driver to the
sg_miter API, which correctly handles sgs which span multiple pages.
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>
Signed-off-by: Rabin Vincent <rabin.vincent@xxxxxxxxxxxxxx>
---
v2:
- Keep the flush_dcache_page() inside the driver, since the
flush_kernel_dcache_page() call inside the sg_miter API is inadequate
drivers/mmc/host/mmci.c | 60 +++++++++++++++++++++++++++++-----------------
drivers/mmc/host/mmci.h | 35 +--------------------------
2 files changed, 39 insertions(+), 56 deletions(-)
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 4917af9..d63d756 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -26,7 +26,6 @@
#include <linux/amba/mmci.h>
#include <linux/regulator/consumer.h>
-#include <asm/cacheflush.h>
#include <asm/div64.h>
#include <asm/io.h>
#include <asm/sizes.h>
@@ -98,6 +97,18 @@ static void mmci_stop_data(struct mmci_host *host)
host->data = NULL;
}
+static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
+{
+ unsigned int flags = SG_MITER_ATOMIC;
+
+ 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);
+}
+
static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
{
unsigned int datactrl, timeout, irqmask;
@@ -210,8 +221,17 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
* We hit an error condition. Ensure that any data
* partially written to a page is properly coherent.
*/
- if (host->sg_len && data->flags & MMC_DATA_READ)
- flush_dcache_page(sg_page(host->sg_ptr));
+ if (data->flags & MMC_DATA_READ) {
+ struct sg_mapping_iter *sg_miter = &host->sg_miter;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ if (sg_miter_next(sg_miter)) {
+ flush_dcache_page(sg_miter->page);
+ sg_miter_stop(sg_miter);
+ }
+ local_irq_restore(flags);
+ }
}
if (status & MCI_DATAEND) {
mmci_stop_data(host);
@@ -314,15 +334,18 @@ static int mmci_pio_write(struct mmci_host *host, char *buffer, unsigned int rem
static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
{
struct mmci_host *host = dev_id;
+ struct sg_mapping_iter *sg_miter = &host->sg_miter;
void __iomem *base = host->base;
+ unsigned long flags;
u32 status;
status = readl(base + MMCISTATUS);
dev_dbg(mmc_dev(host->mmc), "irq1 (pio) %08x\n", status);
+ local_irq_save(flags);
+
do {
- unsigned long flags;
unsigned int remain, len;
char *buffer;
@@ -336,11 +359,11 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
if (!(status & (MCI_TXFIFOHALFEMPTY|MCI_RXDATAAVLBL)))
break;
- /*
- * Map the current scatter buffer.
- */
- buffer = mmci_kmap_atomic(host, &flags) + host->sg_off;
- remain = host->sg_ptr->length - host->sg_off;
+ if (!sg_miter_next(sg_miter))
+ break;
+
+ buffer = sg_miter->addr;
+ remain = sg_miter->length;
len = 0;
if (status & MCI_RXACTIVE)
@@ -348,31 +371,24 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id)
if (status & MCI_TXACTIVE)
len = mmci_pio_write(host, buffer, remain, status);
- /*
- * Unmap the buffer.
- */
- mmci_kunmap_atomic(host, buffer, &flags);
+ sg_miter->consumed = len;
- host->sg_off += len;
host->size -= len;
remain -= len;
if (remain)
break;
- /*
- * If we were reading, and we have completed this
- * page, ensure that the data cache is coherent.
- */
if (status & MCI_RXACTIVE)
- flush_dcache_page(sg_page(host->sg_ptr));
-
- if (!mmci_next_sg(host))
- break;
+ flush_dcache_page(sg_miter->page);
status = readl(base + MMCISTATUS);
} while (1);
+ sg_miter_stop(sg_miter);
+
+ local_irq_restore(flags);
+
/*
* If we're nearing the end of the read, switch to
* "any data available" mode.
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index d77062e..7cb24ab 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -171,42 +171,9 @@ struct mmci_host {
struct timer_list timer;
unsigned int oldstat;
- unsigned int sg_len;
-
/* pio stuff */
- struct scatterlist *sg_ptr;
- unsigned int sg_off;
+ struct sg_mapping_iter sg_miter;
unsigned int size;
struct regulator *vcc;
};
-static inline void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
-{
- /*
- * Ideally, we want the higher levels to pass us a scatter list.
- */
- host->sg_len = data->sg_len;
- host->sg_ptr = data->sg;
- host->sg_off = 0;
-}
-
-static inline int mmci_next_sg(struct mmci_host *host)
-{
- host->sg_ptr++;
- host->sg_off = 0;
- return --host->sg_len;
-}
-
-static inline char *mmci_kmap_atomic(struct mmci_host *host, unsigned long *flags)
-{
- struct scatterlist *sg = host->sg_ptr;
-
- local_irq_save(*flags);
- return kmap_atomic(sg_page(sg), KM_BIO_SRC_IRQ) + sg->offset;
-}
-
-static inline void mmci_kunmap_atomic(struct mmci_host *host, void *buffer, unsigned long *flags)
-{
- kunmap_atomic(buffer, KM_BIO_SRC_IRQ);
- local_irq_restore(*flags);
-}
--
1.7.0
--
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