From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH 1/7] mmc: sdhci: add support for using external DMA devices References: <20190111110851.6805-1-faiz_abbas@ti.com> <20190111110851.6805-2-faiz_abbas@ti.com> <1324fd22-e879-6ee6-910b-baada4779670@intel.com> From: Adrian Hunter Message-ID: <242d0a0f-1235-1f0c-e30a-95dc4a22e01b@intel.com> Date: Mon, 14 Jan 2019 10:47:18 +0200 MIME-Version: 1.0 In-Reply-To: <1324fd22-e879-6ee6-910b-baada4779670@intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit To: Faiz Abbas , linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-mmc@vger.kernel.org Cc: zhang.chunyan@linaro.org, kishon@ti.com, mark.rutland@arm.com, robh+dt@kernel.org, ulf.hansson@linaro.org List-ID: On 14/01/19 10:45 AM, Adrian Hunter wrote: > On 11/01/19 1:08 PM, Faiz Abbas wrote: >> From: Chunyan Zhang >> >> Some standard SD host controllers can support both external dma >> controllers as well as ADMA/SDMA in which the SD host controller >> acts as DMA master. TI's omap controller is the case as an example. >> >> Currently the generic SDHCI code supports ADMA/SDMA integrated in >> the host controller but does not have any support for external DMA >> controllers implemented using dmaengine, meaning that custom code is >> needed for any systems that use an external DMA controller with SDHCI. >> >> Fixes by Faiz Abbas : >> 1. Map scatterlists before dmaengine_prep_slave_sg() >> 2. Use dma_async() functions inside of the send_command() path and >> synchronize once at the start of each request. >> >> Signed-off-by: Chunyan Zhang >> Signed-off-by: Faiz Abbas > > Acked-by: Adrian Hunter Urgh! Replied to the wrong email sorry haven't looked at this yet. Please disregard the Ack at this time. > >> --- >> drivers/mmc/host/Kconfig | 3 + >> drivers/mmc/host/sdhci.c | 266 ++++++++++++++++++++++++++++++++++++++- >> drivers/mmc/host/sdhci.h | 8 ++ >> 3 files changed, 273 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig >> index e26b8145efb3..333292e8ecdd 100644 >> --- a/drivers/mmc/host/Kconfig >> +++ b/drivers/mmc/host/Kconfig >> @@ -999,3 +999,6 @@ config MMC_SDHCI_AM654 >> If you have a controller with this interface, say Y or M here. >> >> If unsure, say N. >> + >> +config MMC_SDHCI_EXTERNAL_DMA >> + bool >> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >> index a22e11a65658..4a9044c06e21 100644 >> --- a/drivers/mmc/host/sdhci.c >> +++ b/drivers/mmc/host/sdhci.c >> @@ -14,6 +14,7 @@ >> */ >> >> #include >> +#include >> #include >> #include >> #include >> @@ -1118,6 +1119,226 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_command *cmd) >> } >> } >> >> +#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 inline 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 (cookie < 0) >> + 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 int __sdhci_external_dma_prepare_data(struct sdhci_host *host, >> + struct mmc_command *cmd) >> +{ >> + struct mmc_data *data = cmd->data; >> + >> + host->data_timeout = 0; >> + >> + if (sdhci_data_line_cmd(cmd)) >> + sdhci_set_timeout(host, cmd); >> + >> + WARN_ON(host->data); >> + >> + /* Sanity checks */ >> + WARN_ON(data->blksz * data->blocks > 524288); >> + WARN_ON(data->blksz > host->mmc->max_blk_size); >> + WARN_ON(data->blocks > 65535); >> + >> + host->flags |= SDHCI_REQ_USE_DMA; >> + host->data = data; >> + host->data_early = 0; >> + host->data->bytes_xfered = 0; >> + >> + sdhci_set_transfer_irqs(host); >> + >> + /* >> + * For Version 4.10 onwards, if v4 mode is enabled, 32-bit Block Count >> + * can be supported, in that case 16-bit block count register must be 0. >> + */ >> + if (host->version >= SDHCI_SPEC_410 && host->v4_mode && >> + (host->quirks2 & SDHCI_QUIRK2_USE_32BIT_BLK_CNT)) { >> + if (sdhci_readw(host, SDHCI_BLOCK_COUNT)) >> + sdhci_writew(host, 0, SDHCI_BLOCK_COUNT); >> + sdhci_writew(host, data->blocks, SDHCI_32BIT_BLK_CNT); >> + } else { >> + sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT); >> + } >> + >> + return 0; >> +} >> + >> +static void sdhci_external_dma_prepare_data(struct sdhci_host *host, >> + struct mmc_command *cmd) >> +{ >> + struct mmc_data *data = cmd->data; >> + >> + if (!data) >> + return; >> + >> + if (sdhci_external_dma_setup(host, cmd) || >> + __sdhci_external_dma_prepare_data(host, cmd)) { >> + 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 || cmd->opcode == MMC_SET_BLOCK_COUNT) >> + return; >> + >> + sdhci_writew(host, cmd->data->blksz, SDHCI_BLOCK_SIZE); >> + chan = sdhci_external_dma_channel(host, cmd->data); >> + if (chan) >> + dma_async_issue_pending(chan); >> +} >> + >> +static int sdhci_external_dma_cleanup(struct sdhci_host *host, >> + struct mmc_data *data) >> +{ >> + struct dma_chan *chan = sdhci_external_dma_channel(host, data); >> + int ret = 0; >> + >> + if (chan) >> + ret = dmaengine_terminate_async(chan); >> + >> + return ret; >> +} >> +#else >> +static int sdhci_external_dma_init(struct sdhci_host *host) >> +{ >> + return -EOPNOTSUPP; >> +} >> + >> +static void sdhci_external_dma_release(struct sdhci_host *host) >> +{} >> + >> +static void sdhci_external_dma_prepare_data(struct sdhci_host *host, >> + struct mmc_command *cmd) >> +{ >> + /* If MMC_SDHCI_EXTERNAL_DMA not supported, PIO will be used */ >> + sdhci_prepare_data(host, cmd); >> +} >> + >> +static void sdhci_external_dma_pre_transfer(struct sdhci_host *host, >> + struct mmc_command *cmd) >> +{} >> + >> +static int sdhci_external_dma_cleanup(struct sdhci_host *host, >> + struct mmc_data *data) >> +{ >> + return 0; >> +} >> +#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) >> { >> @@ -1374,7 +1595,10 @@ void sdhci_send_command(struct sdhci_host *host, struct mmc_command *cmd) >> host->data_cmd = cmd; >> } >> >> - sdhci_prepare_data(host, cmd); >> + 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); >> >> @@ -1416,6 +1640,9 @@ 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); >> @@ -1781,6 +2008,11 @@ void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq) >> >> sdhci_led_activate(host); >> >> + if (host->use_external_dma && mrq->data) { >> + struct dma_chan *chan = sdhci_external_dma_channel(host, >> + mrq->data); >> + dmaengine_synchronize(chan); >> + } >> /* >> * Ensure we don't send the STOP for non-SET_BLOCK_COUNTED >> * requests if Auto-CMD12 is enabled. >> @@ -2658,6 +2890,8 @@ static bool sdhci_request_done(struct sdhci_host *host) >> dma_unmap_sg(mmc_dev(host->mmc), data->sg, >> data->sg_len, >> mmc_get_dma_dir(data)); >> + if (host->use_external_dma) >> + sdhci_external_dma_cleanup(host, data); >> } >> data->host_cookie = COOKIE_UNMAPPED; >> } >> @@ -3692,12 +3926,15 @@ int sdhci_setup_host(struct sdhci_host *host) >> mmc_hostname(mmc), host->version); >> } >> >> - if (host->quirks & SDHCI_QUIRK_FORCE_DMA) >> + if (host->quirks & SDHCI_QUIRK_FORCE_DMA) { >> host->flags |= SDHCI_USE_SDMA; >> - else if (!(host->caps & SDHCI_CAN_DO_SDMA)) >> + } else if (!(host->caps & SDHCI_CAN_DO_SDMA)) { >> DBG("Controller doesn't have SDMA capability\n"); >> - else >> + } else if (host->use_external_dma) { >> + /* Using dma-names to detect external dma capability */ >> + } else { >> host->flags |= SDHCI_USE_SDMA; >> + } >> >> if ((host->quirks & SDHCI_QUIRK_BROKEN_DMA) && >> (host->flags & SDHCI_USE_SDMA)) { >> @@ -3785,6 +4022,19 @@ int sdhci_setup_host(struct sdhci_host *host) >> } >> } >> >> + 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. >> + */ >> + if (ret) >> + sdhci_switch_external_dma(host, false); >> + } >> + >> /* >> * If we use DMA, then it's up to the caller to set the DMA >> * mask, but PIO does not need the hw shim so we set a new >> @@ -4201,6 +4451,10 @@ 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; >> } >> @@ -4247,6 +4501,7 @@ 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"); >> @@ -4335,6 +4590,9 @@ 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 6cc9a3c2ac66..7a52823ebef4 100644 >> --- a/drivers/mmc/host/sdhci.h >> +++ b/drivers/mmc/host/sdhci.h >> @@ -482,6 +482,7 @@ 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; >> @@ -531,6 +532,7 @@ 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 */ >> @@ -559,6 +561,11 @@ 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 */ >> @@ -792,5 +799,6 @@ void sdhci_start_tuning(struct sdhci_host *host); >> 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_switch_external_dma(struct sdhci_host *host, bool en); >> >> #endif /* __SDHCI_HW_H */ >> > >