From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22101C33CB1 for ; Wed, 15 Jan 2020 12:02:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF7E12187F for ; Wed, 15 Jan 2020 12:02:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730177AbgAOMCU (ORCPT ); Wed, 15 Jan 2020 07:02:20 -0500 Received: from mga12.intel.com ([192.55.52.136]:43537 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729892AbgAOMCU (ORCPT ); Wed, 15 Jan 2020 07:02:20 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Jan 2020 04:02:18 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,322,1574150400"; d="scan'208";a="397864191" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.167]) ([10.237.72.167]) by orsmga005.jf.intel.com with ESMTP; 15 Jan 2020 04:02:15 -0800 Subject: Re: [PATCH v4 03/11] mmc: sdhci: add support for using external DMA devices To: Faiz Abbas , linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-mmc@vger.kernel.org Cc: kishon@ti.com, mark.rutland@arm.com, robh+dt@kernel.org, ulf.hansson@linaro.org, tony@atomide.com References: <20200106110133.13791-1-faiz_abbas@ti.com> <20200106110133.13791-4-faiz_abbas@ti.com> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: Date: Wed, 15 Jan 2020 14:01:22 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20200106110133.13791-4-faiz_abbas@ti.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org On 6/01/20 1:01 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 call > terminate_sync() in non-atomic context in case of an error. > > Signed-off-by: Chunyan Zhang > Signed-off-by: Faiz Abbas Notwithstanding comments from other people: Acked-by: Adrian Hunter > --- > drivers/mmc/host/Kconfig | 3 + > drivers/mmc/host/sdhci.c | 228 ++++++++++++++++++++++++++++++++++++++- > 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 f6999054abcf..8cc78c76bc3d 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -10,6 +10,7 @@ > */ > > #include > +#include > #include > #include > #include > @@ -1157,6 +1158,188 @@ 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 (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 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) > { > @@ -1408,8 +1591,12 @@ 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); > > @@ -1451,6 +1638,9 @@ 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); > @@ -2675,6 +2865,17 @@ 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) { > /* > @@ -3810,6 +4011,21 @@ 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); > @@ -4290,6 +4506,10 @@ 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; > } > @@ -4335,6 +4555,7 @@ 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"); > @@ -4423,6 +4644,9 @@ 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 */ >