@@ -1040,3 +1040,6 @@ config MMC_OWL
help
This selects support for the SD/MMC Host Controller on
Actions Semi Owl SoCs.
+
+config MMC_SDHCI_EXTERNAL_DMA
+ bool
@@ -10,6 +10,7 @@
*/
#include <linux/delay.h>
+#include <linux/dmaengine.h>
#include <linux/ktime.h>
#include <linux/highmem.h>
#include <linux/io.h>
@@ -1155,6 +1156,188 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd)
sdhci_set_block_info(host, data);
}
+#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
+
+static int sdhci_external_dma_init(struct sdhci_host *host)
+{
+ int ret = 0;
+ struct mmc_host *mmc = host->mmc;
+
+ host->tx_chan = dma_request_chan(mmc->parent, "tx");
+ if (IS_ERR(host->tx_chan)) {
+ ret = PTR_ERR(host->tx_chan);
+ if (ret != -EPROBE_DEFER)
+ pr_warn("Failed to request TX DMA channel.\n");
+ host->tx_chan = NULL;
+ return ret;
+ }
+
+ host->rx_chan = dma_request_chan(mmc->parent, "rx");
+ if (IS_ERR(host->rx_chan)) {
+ if (host->tx_chan) {
+ dma_release_channel(host->tx_chan);
+ host->tx_chan = NULL;
+ }
+
+ ret = PTR_ERR(host->rx_chan);
+ if (ret != -EPROBE_DEFER)
+ pr_warn("Failed to request RX DMA channel.\n");
+ host->rx_chan = NULL;
+ }
+
+ return ret;
+}
+
+static struct dma_chan *sdhci_external_dma_channel(struct sdhci_host *host,
+ struct mmc_data *data)
+{
+ return data->flags & MMC_DATA_WRITE ? host->tx_chan : host->rx_chan;
+}
+
+static int sdhci_external_dma_setup(struct sdhci_host *host,
+ struct mmc_command *cmd)
+{
+ int ret, i;
+ struct dma_async_tx_descriptor *desc;
+ struct mmc_data *data = cmd->data;
+ struct dma_chan *chan;
+ struct dma_slave_config cfg;
+ dma_cookie_t cookie;
+ int sg_cnt;
+
+ if (!host->mapbase)
+ return -EINVAL;
+
+ cfg.src_addr = host->mapbase + SDHCI_BUFFER;
+ cfg.dst_addr = host->mapbase + SDHCI_BUFFER;
+ cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ cfg.src_maxburst = data->blksz / 4;
+ cfg.dst_maxburst = data->blksz / 4;
+
+ /* Sanity check: all the SG entries must be aligned by block size. */
+ for (i = 0; i < data->sg_len; i++) {
+ if ((data->sg + i)->length % data->blksz)
+ return -EINVAL;
+ }
+
+ chan = sdhci_external_dma_channel(host, data);
+
+ ret = dmaengine_slave_config(chan, &cfg);
+ if (ret)
+ return ret;
+
+ sg_cnt = sdhci_pre_dma_transfer(host, data, COOKIE_MAPPED);
+ if (sg_cnt <= 0)
+ return -EINVAL;
+
+ desc = dmaengine_prep_slave_sg(chan, data->sg, data->sg_len,
+ mmc_get_dma_dir(data),
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!desc)
+ return -EINVAL;
+
+ desc->callback = NULL;
+ desc->callback_param = NULL;
+
+ cookie = dmaengine_submit(desc);
+ if (dma_submit_error(cookie))
+ ret = cookie;
+
+ return ret;
+}
+
+static void sdhci_external_dma_release(struct sdhci_host *host)
+{
+ if (host->tx_chan) {
+ dma_release_channel(host->tx_chan);
+ host->tx_chan = NULL;
+ }
+
+ if (host->rx_chan) {
+ dma_release_channel(host->rx_chan);
+ host->rx_chan = NULL;
+ }
+
+ sdhci_switch_external_dma(host, false);
+}
+
+static void __sdhci_external_dma_prepare_data(struct sdhci_host *host,
+ struct mmc_command *cmd)
+{
+ struct mmc_data *data = cmd->data;
+
+ sdhci_initialize_data(host, data);
+
+ host->flags |= SDHCI_REQ_USE_DMA;
+ sdhci_set_transfer_irqs(host);
+
+ sdhci_set_block_info(host, data);
+}
+
+static void sdhci_external_dma_prepare_data(struct sdhci_host *host,
+ struct mmc_command *cmd)
+{
+ if (!sdhci_external_dma_setup(host, cmd)) {
+ __sdhci_external_dma_prepare_data(host, cmd);
+ } else {
+ sdhci_external_dma_release(host);
+ pr_err("%s: Cannot use external DMA, switch to the DMA/PIO which standard SDHCI provides.\n",
+ mmc_hostname(host->mmc));
+ sdhci_prepare_data(host, cmd);
+ }
+}
+
+static void sdhci_external_dma_pre_transfer(struct sdhci_host *host,
+ struct mmc_command *cmd)
+{
+ struct dma_chan *chan;
+
+ if (!cmd->data)
+ return;
+
+ chan = sdhci_external_dma_channel(host, cmd->data);
+ if (chan)
+ dma_async_issue_pending(chan);
+}
+
+#else
+
+static inline int sdhci_external_dma_init(struct sdhci_host *host)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline void sdhci_external_dma_release(struct sdhci_host *host)
+{
+}
+
+static inline void sdhci_external_dma_prepare_data(struct sdhci_host *host,
+ struct mmc_command *cmd)
+{
+ /* This should never happen */
+ WARN_ON_ONCE(1);
+}
+
+static inline void sdhci_external_dma_pre_transfer(struct sdhci_host *host,
+ struct mmc_command *cmd)
+{
+}
+
+static inline struct dma_chan *sdhci_external_dma_channel(struct sdhci_host *host,
+ struct mmc_data *data)
+{
+ return NULL;
+}
+
+#endif
+
+void sdhci_switch_external_dma(struct sdhci_host *host, bool en)
+{
+ host->use_external_dma = en;
+}
+EXPORT_SYMBOL_GPL(sdhci_switch_external_dma);
+
static inline bool sdhci_auto_cmd12(struct sdhci_host *host,
struct mmc_request *mrq)
{
@@ -1406,8 +1589,12 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
sdhci_set_timeout(host, cmd);
}
- if (cmd->data)
- sdhci_prepare_data(host, cmd);
+ if (cmd->data) {
+ if (host->use_external_dma)
+ sdhci_external_dma_prepare_data(host, cmd);
+ else
+ sdhci_prepare_data(host, cmd);
+ }
sdhci_writel(host, cmd->arg, SDHCI_ARGUMENT);
@@ -1449,6 +1636,9 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd)
timeout += 10 * HZ;
sdhci_mod_timer(host, cmd->mrq, timeout);
+ if (host->use_external_dma)
+ sdhci_external_dma_pre_transfer(host, cmd);
+
sdhci_writew(host, SDHCI_MAKE_CMD(cmd->opcode, flags), SDHCI_COMMAND);
}
EXPORT_SYMBOL_GPL(sdhci_send_command);
@@ -2673,6 +2863,17 @@ static bool sdhci_request_done(struct sdhci_host *host)
if (host->flags & SDHCI_REQ_USE_DMA) {
struct mmc_data *data = mrq->data;
+ if (host->use_external_dma && data &&
+ (mrq->cmd->error || data->error)) {
+ struct dma_chan *chan = sdhci_external_dma_channel(host, data);
+
+ host->mrqs_done[i] = NULL;
+ spin_unlock_irqrestore(&host->lock, flags);
+ dmaengine_terminate_sync(chan);
+ spin_lock_irqsave(&host->lock, flags);
+ sdhci_set_mrq_done(host, mrq);
+ }
+
if (data && data->host_cookie == COOKIE_MAPPED) {
if (host->bounce_buffer) {
/*
@@ -3808,6 +4009,21 @@ int sdhci_setup_host(struct sdhci_host *host)
if (sdhci_can_64bit_dma(host))
host->flags |= SDHCI_USE_64_BIT_DMA;
+ if (host->use_external_dma) {
+ ret = sdhci_external_dma_init(host);
+ if (ret == -EPROBE_DEFER)
+ goto unreg;
+ /*
+ * Fall back to use the DMA/PIO integrated in standard SDHCI
+ * instead of external DMA devices.
+ */
+ else if (ret)
+ sdhci_switch_external_dma(host, false);
+ /* Disable internal DMA sources */
+ else
+ host->flags &= ~(SDHCI_USE_SDMA | SDHCI_USE_ADMA);
+ }
+
if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
if (host->ops->set_dma_mask)
ret = host->ops->set_dma_mask(host);
@@ -4288,6 +4504,10 @@ void sdhci_cleanup_host(struct sdhci_host *host)
dma_free_coherent(mmc_dev(mmc), host->align_buffer_sz +
host->adma_table_sz, host->align_buffer,
host->align_addr);
+
+ if (host->use_external_dma)
+ sdhci_external_dma_release(host);
+
host->adma_table = NULL;
host->align_buffer = NULL;
}
@@ -4333,6 +4553,7 @@ int __sdhci_add_host(struct sdhci_host *host)
pr_info("%s: SDHCI controller on %s [%s] using %s\n",
mmc_hostname(mmc), host->hw_name, dev_name(mmc_dev(mmc)),
+ host->use_external_dma ? "External DMA" :
(host->flags & SDHCI_USE_ADMA) ?
(host->flags & SDHCI_USE_64_BIT_DMA) ? "ADMA 64-bit" : "ADMA" :
(host->flags & SDHCI_USE_SDMA) ? "DMA" : "PIO");
@@ -4421,6 +4642,9 @@ void sdhci_remove_host(struct sdhci_host *host, int dead)
host->adma_table_sz, host->align_buffer,
host->align_addr);
+ if (host->use_external_dma)
+ sdhci_external_dma_release(host);
+
host->adma_table = NULL;
host->align_buffer = NULL;
}
@@ -487,6 +487,7 @@ struct sdhci_host {
int irq; /* Device IRQ */
void __iomem *ioaddr; /* Mapped address */
+ phys_addr_t mapbase; /* physical address base */
char *bounce_buffer; /* For packing SDMA reads/writes */
dma_addr_t bounce_addr;
unsigned int bounce_buffer_size;
@@ -535,6 +536,7 @@ struct sdhci_host {
bool pending_reset; /* Cmd/data reset is pending */
bool irq_wake_enabled; /* IRQ wakeup is enabled */
bool v4_mode; /* Host Version 4 Enable */
+ bool use_external_dma; /* Host selects to use external DMA */
struct mmc_request *mrqs_done[SDHCI_MAX_MRQS]; /* Requests done */
struct mmc_command *cmd; /* Current command */
@@ -564,6 +566,11 @@ struct sdhci_host {
struct timer_list timer; /* Timer for timeouts */
struct timer_list data_timer; /* Timer for data timeouts */
+#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
+ struct dma_chan *rx_chan;
+ struct dma_chan *tx_chan;
+#endif
+
u32 caps; /* CAPABILITY_0 */
u32 caps1; /* CAPABILITY_1 */
bool read_caps; /* Capability flags have been read */
@@ -795,5 +802,6 @@ void sdhci_end_tuning(struct sdhci_host *host);
void sdhci_reset_tuning(struct sdhci_host *host);
void sdhci_send_tuning(struct sdhci_host *host, u32 opcode);
void sdhci_abort_tuning(struct sdhci_host *host, u32 opcode);
+void sdhci_switch_external_dma(struct sdhci_host *host, bool en);
#endif /* __SDHCI_HW_H */