DMA memory cannot cross specific boundary for some SDHCI controller,
such as DesignWare SDHCI controller. Add DMA memory boundary dt
property and workaround the limitation.
Signed-off-by: Jun Nie <jun.nie@xxxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 20 +++++++++++++++++++-
drivers/mmc/host/sdhci.h | 1 +
2 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index d8a6c1c91448..56c53fbadd9d 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -763,9 +763,25 @@ static void sdhci_adma_table_pre(struct sdhci_host *host,
BUG_ON(len > 65536);
/* tran, valid */
- if (len)
+ if (len) {
+ unsigned int boundary = host->dma_mem_boundary;
+ /*
+ * work around for buffer across mem boundary, split
+ * the buffer.
+ */
+ if (boundary &&
+ ((addr & (boundary - 1)) + len) > boundary) {
+ offset = boundary - (addr & (boundary - 1));
+ __sdhci_adma_write_desc(host, &desc,
+ addr, offset,
+ ADMA2_TRAN_VALID);
+ addr += offset;
+ len -= offset;
+ }
+
__sdhci_adma_write_desc(host, &desc, addr, len,
ADMA2_TRAN_VALID);
+ }
/*
* If this triggers then we have a calculation bug
@@ -3634,6 +3650,8 @@ void __sdhci_read_caps(struct sdhci_host *host, const u16 *ver,
"sdhci-caps-mask", &dt_caps_mask);
of_property_read_u64(mmc_dev(host->mmc)->of_node,
"sdhci-caps", &dt_caps);
+ of_property_read_u32(mmc_dev(host->mmc)->of_node,
+ "sdhci-dma-mem-boundary", &host->dma_mem_boundary);
if (of_property_read_u32(mmc_dev(host->mmc)->of_node,
"sdhci-ctrl-hs400", &host->sdhci_ctrl_hs400))
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index cac4d819f62c..954ac08c4fb0 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -608,6 +608,7 @@ struct sdhci_host {
/* SDHCI_CTRL_HS400 value */
u32 sdhci_ctrl_hs400;
+ u32 dma_mem_boundary;
unsigned long private[0] ____cacheline_aligned;
};
--
2.17.1
