mmc: sdhci: Fix ADMA for PAGE_SIZE >= 64KiB

The block layer forces a minimum segment size of PAGE_SIZE, so a segment
can be too big for the ADMA table, if PAGE_SIZE >= 64KiB. Fix by writing
multiple descriptors, noting that the ADMA table is sized for 4KiB chunks
anyway, so it will be big enough.

Reported-and-tested-by: Bough Chen <haibo.chen@nxp.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211115082345.802238-1-adrian.hunter@intel.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 269c865694024c8f2164574349352a299eacf5d2..07c6da1f2f0fe7b38414ab0afa273c3f912ec20e 100644 (file)
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -771,7 +771,19 @@ static void sdhci_adma_table_pre(struct sdhci_host *host,
                        len -= offset;
                }
 
-               BUG_ON(len > 65536);
+               /*
+                * The block layer forces a minimum segment size of PAGE_SIZE,
+                * so 'len' can be too big here if PAGE_SIZE >= 64KiB. Write
+                * multiple descriptors, noting that the ADMA table is sized
+                * for 4KiB chunks anyway, so it will be big enough.
+                */
+               while (len > host->max_adma) {
+                       int n = 32 * 1024; /* 32KiB*/
+
+                       __sdhci_adma_write_desc(host, &desc, addr, n, ADMA2_TRAN_VALID);
+                       addr += n;
+                       len -= n;
+               }
 
                /* tran, valid */
                if (len)
@@ -3968,6 +3980,7 @@ struct sdhci_host *sdhci_alloc_host(struct device *dev,
         * descriptor for each segment, plus 1 for a nop end descriptor.
         */
        host->adma_table_cnt = SDHCI_MAX_SEGS * 2 + 1;
+       host->max_adma = 65536;
 
        host->max_timeout_count = 0xE;
 
@@ -4633,10 +4646,12 @@ int sdhci_setup_host(struct sdhci_host *host)
         * be larger than 64 KiB though.
         */
        if (host->flags & SDHCI_USE_ADMA) {
-               if (host->quirks & SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC)
+               if (host->quirks & SDHCI_QUIRK_BROKEN_ADMA_ZEROLEN_DESC) {
+                       host->max_adma = 65532; /* 32-bit alignment */
                        mmc->max_seg_size = 65535;
-               else
+               } else {
                        mmc->max_seg_size = 65536;
+               }
        } else {
                mmc->max_seg_size = mmc->max_req_size;
        }

diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index bb883553d3b461982ffca66d7a7b23aaa7c70729..d7929d72573006bd388511f66fdde315af449fd2 100644 (file)
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -340,7 +340,8 @@ struct sdhci_adma2_64_desc {
 
 /*
  * Maximum segments assuming a 512KiB maximum requisition size and a minimum
- * 4KiB page size.
+ * 4KiB page size. Note this also allows enough for multiple descriptors in
+ * case of PAGE_SIZE >= 64KiB.
  */
 #define SDHCI_MAX_SEGS         128
 
@@ -543,6 +544,7 @@ struct sdhci_host {
        unsigned int blocks;    /* remaining PIO blocks */
 
        int sg_count;           /* Mapped sg entries */
+       int max_adma;           /* Max. length in ADMA descriptor */
 
        void *adma_table;       /* ADMA descriptor table */
        void *align_buffer;     /* Bounce buffer */