diff options
| -rw-r--r-- | drivers/mmc/host/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/mmc/host/sdhci.c | 228 | ||||
| -rw-r--r-- | drivers/mmc/host/sdhci.h | 8 |
3 files changed, 237 insertions, 2 deletions
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig index d06b2dfe3c95..adef971582a1 100644 --- a/drivers/mmc/host/Kconfig +++ b/drivers/mmc/host/Kconfig @@ -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 diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index f97f07179d45..fb4a9e87e119 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -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); @@ -2662,6 +2852,17 @@ 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) { /* @@ -3797,6 +3998,21 @@ 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); @@ -4277,6 +4493,10 @@ 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; } @@ -4322,6 +4542,7 @@ 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"); @@ -4410,6 +4631,9 @@ 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; } diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index fe83ece6965b..3166b3ecef89 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -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 */ |