[PATCH V2 3/7] mmc: sdhci: add ADMA2 64-bit addressing support for V4 mode

From: Chunyan Zhang
Date: Thu Jun 14 2018 - 22:05:07 EST


ADMA2 64-bit addressing support is divided into V3 mode and V4 mode.
So there are two kinds of descriptors for ADMA2 64-bit addressing
i.e. 96-bit Descriptor for V3 mode, and 128-bit Descriptor for V4
mode. 128-bit Descriptor is aligned to 8-byte.

For V4 mode, ADMA2 64-bit addressing is enabled via Host Control 2
register.

Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 50 +++++++++++++++++++++++++++++++++++-------------
drivers/mmc/host/sdhci.h | 23 +++++++++++++++++-----
2 files changed, 55 insertions(+), 18 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index f57201f..5d3b0d8 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -585,6 +585,8 @@ static void sdhci_adma_table_pre(struct sdhci_host *host,
void *desc, *align;
char *buffer;
int len, offset, i;
+ unsigned int adma2_align = SDHCI_ADMA2_ALIGN(host);
+ unsigned int adma2_mask = SDHCI_ADMA2_MASK(host);

/*
* The spec does not specify endianness of descriptor table.
@@ -608,8 +610,8 @@ static void sdhci_adma_table_pre(struct sdhci_host *host,
* buffer for the (up to three) bytes that screw up the
* alignment.
*/
- offset = (SDHCI_ADMA2_ALIGN - (addr & SDHCI_ADMA2_MASK)) &
- SDHCI_ADMA2_MASK;
+ offset = (adma2_align - (addr & adma2_align)) &
+ adma2_mask;
if (offset) {
if (data->flags & MMC_DATA_WRITE) {
buffer = sdhci_kmap_atomic(sg, &flags);
@@ -623,8 +625,8 @@ static void sdhci_adma_table_pre(struct sdhci_host *host,

BUG_ON(offset > 65536);

- align += SDHCI_ADMA2_ALIGN;
- align_addr += SDHCI_ADMA2_ALIGN;
+ align += adma2_align;
+ align_addr += adma2_align;

desc += host->desc_sz;

@@ -668,13 +670,15 @@ static void sdhci_adma_table_post(struct sdhci_host *host,
void *align;
char *buffer;
unsigned long flags;
+ unsigned int adma2_align = SDHCI_ADMA2_ALIGN(host);
+ unsigned int adma2_mask = SDHCI_ADMA2_MASK(host);

if (data->flags & MMC_DATA_READ) {
bool has_unaligned = false;

/* Do a quick scan of the SG list for any unaligned mappings */
for_each_sg(data->sg, sg, host->sg_count, i)
- if (sg_dma_address(sg) & SDHCI_ADMA2_MASK) {
+ if (sg_dma_address(sg) & adma2_mask) {
has_unaligned = true;
break;
}
@@ -686,15 +690,15 @@ static void sdhci_adma_table_post(struct sdhci_host *host,
align = host->align_buffer;

for_each_sg(data->sg, sg, host->sg_count, i) {
- if (sg_dma_address(sg) & SDHCI_ADMA2_MASK) {
- size = SDHCI_ADMA2_ALIGN -
- (sg_dma_address(sg) & SDHCI_ADMA2_MASK);
+ if (sg_dma_address(sg) & adma2_mask) {
+ size = adma2_align -
+ (sg_dma_address(sg) & adma2_mask);

buffer = sdhci_kmap_atomic(sg, &flags);
memcpy(buffer, align, size);
sdhci_kunmap_atomic(buffer, &flags);

- align += SDHCI_ADMA2_ALIGN;
+ align += adma2_align;
}
}
}
@@ -3400,6 +3404,26 @@ static int sdhci_allocate_bounce_buffer(struct sdhci_host *host)
return 0;
}

+static inline bool sdhci_use_64bit_dma(struct sdhci_host *host)
+{
+ u32 addr64bit_en;
+
+ /*
+ * According to SD Host Controller spec v4.10, bit[27] added from
+ * version 4.10 in Capabilities Register is used as 64-bit System
+ * Address support for V4 mode, 64-bit DMA Addressing for V4 mode
+ * is enabled only if 64-bit Addressing =1 in the Host Control 2
+ * register.
+ */
+ if (host->version == SDHCI_SPEC_410 && host->v4_mode) {
+ addr64bit_en = (sdhci_readw(host, SDHCI_HOST_CONTROL2) &
+ SDHCI_CTRL_64BIT_ADDR);
+ return addr64bit_en && (host->caps & SDHCI_CAN_64BIT_V4);
+ }
+
+ return host->caps & SDHCI_CAN_64BIT;
+}
+
int sdhci_setup_host(struct sdhci_host *host)
{
struct mmc_host *mmc;
@@ -3471,7 +3495,7 @@ int sdhci_setup_host(struct sdhci_host *host)
* SDHCI_QUIRK2_BROKEN_64_BIT_DMA must be left to the drivers to
* implement.
*/
- if (host->caps & SDHCI_CAN_64BIT)
+ if (sdhci_use_64bit_dma(host))
host->flags |= SDHCI_USE_64_BIT_DMA;

if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
@@ -3505,15 +3529,15 @@ int sdhci_setup_host(struct sdhci_host *host)
*/
if (host->flags & SDHCI_USE_64_BIT_DMA) {
host->adma_table_sz = (SDHCI_MAX_SEGS * 2 + 1) *
- SDHCI_ADMA2_64_DESC_SZ;
- host->desc_sz = SDHCI_ADMA2_64_DESC_SZ;
+ SDHCI_ADMA2_64_DESC_SZ(host);
+ host->desc_sz = SDHCI_ADMA2_64_DESC_SZ(host);
} else {
host->adma_table_sz = (SDHCI_MAX_SEGS * 2 + 1) *
SDHCI_ADMA2_32_DESC_SZ;
host->desc_sz = SDHCI_ADMA2_32_DESC_SZ;
}

- host->align_buffer_sz = SDHCI_MAX_SEGS * SDHCI_ADMA2_ALIGN;
+ host->align_buffer_sz = SDHCI_MAX_SEGS * SDHCI_ADMA2_ALIGN(host);
buf = dma_alloc_coherent(mmc_dev(mmc), host->align_buffer_sz +
host->adma_table_sz, &dma, GFP_KERNEL);
if (!buf) {
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 128b0ba..820a863 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -185,6 +185,7 @@
#define SDHCI_CTRL_EXEC_TUNING 0x0040
#define SDHCI_CTRL_TUNED_CLK 0x0080
#define SDHCI_CTRL_V4_MODE 0x1000
+#define SDHCI_CTRL_64BIT_ADDR 0x2000
#define SDHCI_CTRL_PRESET_VAL_ENABLE 0x8000

#define SDHCI_CAPABILITIES 0x40
@@ -206,6 +207,7 @@
#define SDHCI_CAN_VDD_300 0x02000000
#define SDHCI_CAN_VDD_180 0x04000000
#define SDHCI_CAN_64BIT 0x10000000
+#define SDHCI_CAN_64BIT_V4 0x8000000

#define SDHCI_SUPPORT_SDR50 0x00000001
#define SDHCI_SUPPORT_SDR104 0x00000002
@@ -297,9 +299,14 @@ struct sdhci_adma2_32_desc {
__le32 addr;
} __packed __aligned(4);

-/* ADMA2 data alignment */
-#define SDHCI_ADMA2_ALIGN 4
-#define SDHCI_ADMA2_MASK (SDHCI_ADMA2_ALIGN - 1)
+/*
+ * ADMA2 data alignment
+ * According to SD Host Controller spec v4.10, if Host Version 4 Enable is set
+ * in the Host Control 2 register, 128-bit Descriptor will be selected which
+ * shall be aligned 8-byte address boundary.
+ */
+#define SDHCI_ADMA2_ALIGN(host) ((host)->v4_mode ? 8 : 4)
+#define SDHCI_ADMA2_MASK(host) (SDHCI_ADMA2_ALIGN(host) - 1)

/*
* ADMA2 descriptor alignment. Some controllers (e.g. Intel) require 8 byte
@@ -308,8 +315,14 @@ struct sdhci_adma2_32_desc {
*/
#define SDHCI_ADMA2_DESC_ALIGN 8

-/* ADMA2 64-bit DMA descriptor size */
-#define SDHCI_ADMA2_64_DESC_SZ 12
+/*
+ * ADMA2 64-bit DMA descriptor size
+ * According to SD Host Controller spec v4.10, there are two kinds of
+ * descriptors for 64-bit addressing mode: 96-bit Descriptor and 128-bit
+ * Descriptor, if Host Version 4 Enable is set in the Host Control 2
+ * register, 128-bit Descriptor will be selected.
+ */
+#define SDHCI_ADMA2_64_DESC_SZ(host) ((host)->v4_mode ? 16 : 12)

/*
* ADMA2 64-bit descriptor. Note 12-byte descriptor can't always be 8-byte
--
2.7.4