Re: [RFC PATCH v3.1 21/27] mmc: sdhci-uhs2: add irq() and others

Adrian Hunter
2020-12-01T16:47:51Z

On 6/11/20 4:27 am, AKASHI Takahiro wrote:
> This is a UHS-II version of sdhci's request() operation.
> It handles UHS-II related command interrupts and errors.
>
> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> ---
> drivers/mmc/host/sdhci-uhs2.c | 247 ++++++++++++++++++++++++++++++++++
> drivers/mmc/host/sdhci-uhs2.h | 3 +
> drivers/mmc/host/sdhci.c | 112 ++++++++-------
> drivers/mmc/host/sdhci.h | 6 +
> 4 files changed, 319 insertions(+), 49 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> index 36e52553977a..d50134e912f3 100644
> --- a/drivers/mmc/host/sdhci-uhs2.c
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -11,6 +11,7 @@
> */
>
> #include <linux/delay.h>
> +#include <linux/dmaengine.h>
> #include <linux/ktime.h>
> #include <linux/module.h>
> #include <linux/mmc/mmc.h>
> @@ -670,6 +671,12 @@ 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 /* CONFIG_MMC_SDHCI_EXTERNAL_DMA */
>
> static void sdhci_uhs2_finish_data(struct sdhci_host *host)
> @@ -1051,6 +1058,246 @@ static void sdhci_uhs2_finish_command(struct sdhci_host *host)
> }
> }
>
> +/*****************************************************************************\
> + * *
> + * Request done *
> + * *
> +\*****************************************************************************/
> +
> +static bool sdhci_uhs2_request_done(struct sdhci_host *host)
> +{
> + unsigned long flags;
> + struct mmc_request *mrq;
> + int i;
> +
> + /* FIXME: UHS2_INITIALIZED, instead? */
> + if (!(host->mmc->flags & MMC_UHS2_SUPPORT))
> + return sdhci_request_done(host);
> +
> + spin_lock_irqsave(&host->lock, flags);
> +
> + for (i = 0; i < SDHCI_MAX_MRQS; i++) {
> + mrq = host->mrqs_done[i];
> + if (mrq)
> + break;
> + }
> +
> + if (!mrq) {
> + spin_unlock_irqrestore(&host->lock, flags);
> + return true;
> + }
> +
> + /*
> + * Always unmap the data buffers if they were mapped by
> + * sdhci_prepare_data() whenever we finish with a request.
> + * This avoids leaking DMA mappings on error.
> + */
> + 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);
> + }
> +
> + sdhci_request_done_dma(host, mrq);
> + }
> +
> + /*
> + * The controller needs a reset of internal state machines
> + * upon error conditions.
> + */
> + if (sdhci_needs_reset(host, mrq)) {
> + /*
> + * Do not finish until command and data lines are available for
> + * reset. Note there can only be one other mrq, so it cannot
> + * also be in mrqs_done, otherwise host->cmd and host->data_cmd
> + * would both be null.
> + */
> + if (host->cmd || host->data_cmd) {
> + spin_unlock_irqrestore(&host->lock, flags);
> + return true;
> + }
> +
> + /* Some controllers need this kick or reset won't work here */
> + if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)
> + /* This is to force an update */
> + host->ops->set_clock(host, host->clock);
> +
> + sdhci_uhs2_reset(host, SDHCI_UHS2_SW_RESET_SD);

It should be possible to use the ->reset() callback for UHS-II also, then
this function wouldn't be needed.

> + host->pending_reset = false;
> + }
> +
> + host->mrqs_done[i] = NULL;
> +
> + spin_unlock_irqrestore(&host->lock, flags);
> +
> + if (host->ops->request_done)
> + host->ops->request_done(host, mrq);
> + else
> + mmc_request_done(host->mmc, mrq);
> +
> + return false;
> +}
> +
> +static void sdhci_uhs2_complete_work(struct work_struct *work)
> +{
> + struct sdhci_host *host = container_of(work, struct sdhci_host,
> + complete_work);
> +
> + while (!sdhci_uhs2_request_done(host))
> + ;
> +}
> +
> +/*****************************************************************************\
> + * *
> + * Interrupt handling *
> + * *
> +\*****************************************************************************/
> +
> +static void __sdhci_uhs2_irq(struct sdhci_host *host, u32 uhs2mask)
> +{
> + struct mmc_command *cmd = host->cmd;
> +
> + DBG("*** %s got UHS2 error interrupt: 0x%08x\n",
> + mmc_hostname(host->mmc), uhs2mask);
> +
> + if (uhs2mask & SDHCI_UHS2_ERR_INT_STATUS_CMD_MASK) {
> + if (!host->cmd) {
> + pr_err("%s: Got cmd interrupt 0x%08x but no cmd.\n",
> + mmc_hostname(host->mmc),
> + (unsigned int)uhs2mask);
> + sdhci_dumpregs(host);
> + return;
> + }
> + host->cmd->error = -EILSEQ;
> + if (uhs2mask & SDHCI_UHS2_ERR_INT_STATUS_RES_TIMEOUT)
> + host->cmd->error = -ETIMEDOUT;
> + }
> +
> + if (uhs2mask & SDHCI_UHS2_ERR_INT_STATUS_DATA_MASK) {
> + if (!host->data) {
> + pr_err("%s: Got data interrupt 0x%08x but no data.\n",
> + mmc_hostname(host->mmc),
> + (unsigned int)uhs2mask);
> + sdhci_dumpregs(host);
> + return;
> + }
> +
> + if (uhs2mask & SDHCI_UHS2_ERR_INT_STATUS_DEADLOCK_TIMEOUT) {
> + pr_err("%s: Got deadlock timeout interrupt 0x%08x\n",
> + mmc_hostname(host->mmc),
> + (unsigned int)uhs2mask);
> + host->data->error = -ETIMEDOUT;
> + } else if (uhs2mask & SDHCI_UHS2_ERR_INT_STATUS_ADMA) {
> + pr_err("%s: ADMA error = 0x %x\n",
> + mmc_hostname(host->mmc),
> + sdhci_readb(host, SDHCI_ADMA_ERROR));
> + host->data->error = -EIO;
> + } else {
> + host->data->error = -EILSEQ;
> + }
> + }
> +
> + if (host->data && host->data->error)
> + sdhci_uhs2_finish_data(host);
> + else
> + sdhci_finish_mrq(host, cmd->mrq);
> +}
> +
> +u32 sdhci_uhs2_irq(struct sdhci_host *host, u32 intmask)
> +{
> + u32 mask = intmask, uhs2mask;
> +
> + if (!(host->mmc->flags & MMC_UHS2_SUPPORT))
> + goto out;
> +
> + /*
> + * TODO: We should mask Normal Error Interrupt Status Register
> + * in UHS-2 mode so that we don't have to care SD mode errors.
> + */
> + if (intmask & SDHCI_INT_ERROR) {
> + uhs2mask = sdhci_readl(host, SDHCI_UHS2_ERR_INT_STATUS);
> + if (!(uhs2mask & SDHCI_UHS2_ERR_INT_STATUS_MASK))
> + goto cmd_irq;
> +
> + /* Clear error interrupts */
> + sdhci_writel(host, uhs2mask & SDHCI_UHS2_ERR_INT_STATUS_MASK,
> + SDHCI_UHS2_ERR_INT_STATUS);
> +
> + /* Handle error interrupts */
> + __sdhci_uhs2_irq(host, uhs2mask);
> +
> + /* Caller, shdci_irq(), doesn't have to care UHS-2 errors */
> + intmask &= ~SDHCI_INT_ERROR;
> + mask &= SDHCI_INT_ERROR;
> + }
> +
> +cmd_irq:
> + /*
> + * TODO: Cleanup
> + * INT_RESPONSE is enough instead of INT_CMD_MASK, assuming that
> + * INT_ERROR and INT_CMD_MASK won't happen at the same time.
> + */
> + if (intmask & SDHCI_INT_CMD_MASK) {
> + /* Clear command interrupt */
> + sdhci_writel(host, intmask & SDHCI_INT_CMD_MASK,
> + SDHCI_INT_STATUS);
> +
> + /* Handle command interrupt */
> + if (intmask & SDHCI_INT_RESPONSE)
> + sdhci_uhs2_finish_command(host);
> +
> + /* Caller, shdci_irq(), doesn't have to care UHS-2 command */
> + intmask &= ~SDHCI_INT_CMD_MASK;
> + mask &= SDHCI_INT_CMD_MASK;
> + }
> +
> + /* Clear already-handled interrupts. */
> + sdhci_writel(host, mask, SDHCI_INT_STATUS);
> +
> +out:
> + return intmask;
> +}
> +EXPORT_SYMBOL_GPL(sdhci_uhs2_irq);
> +
> +static irqreturn_t sdhci_uhs2_thread_irq(int irq, void *dev_id)
> +{
> + struct sdhci_host *host = dev_id;
> + struct mmc_command *cmd;
> + unsigned long flags;
> + u32 isr;
> +
> + while (!sdhci_uhs2_request_done(host))
> + ;
> +
> + spin_lock_irqsave(&host->lock, flags);
> +
> + isr = host->thread_isr;
> + host->thread_isr = 0;
> +
> + cmd = host->deferred_cmd;

We don't need to use deferred_cmd, so then this function should not be
needed. For UHS-II we should require that the upper layer sends the abort
command, so all the driver needs to do to handle errors, is to reset - which
is already handled by sdhci_request_done() if you make use of the ->reset()
callback.

> + if (cmd && !sdhci_uhs2_send_command_retry(host, cmd, flags))
> + sdhci_finish_mrq(host, cmd->mrq);
> +
> + spin_unlock_irqrestore(&host->lock, flags);
> +
> + if (isr & (SDHCI_INT_CARD_INSERT | SDHCI_INT_CARD_REMOVE)) {
> + struct mmc_host *mmc = host->mmc;
> +
> + mmc->ops->card_event(mmc);
> + mmc_detect_change(mmc, msecs_to_jiffies(200));
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> /*****************************************************************************\
> * *
> * Driver init/exit *
> diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
> index c1ff4ac1ab7a..b74af641d00e 100644
> --- a/drivers/mmc/host/sdhci-uhs2.h
> +++ b/drivers/mmc/host/sdhci-uhs2.h
> @@ -215,5 +215,8 @@ void sdhci_uhs2_set_power(struct sdhci_host *host, unsigned char mode,
> unsigned short vdd);
> void sdhci_uhs2_set_timeout(struct sdhci_host *host, struct mmc_command *cmd);
> void sdhci_uhs2_clear_set_irqs(struct sdhci_host *host, u32 clear, u32 set);
> +void sdhci_uhs2_request(struct mmc_host *mmc, struct mmc_request *mrq);
> +int sdhci_uhs2_request_atomic(struct mmc_host *mmc, struct mmc_request *mrq);
> +u32 sdhci_uhs2_irq(struct sdhci_host *host, u32 intmask);
>
> #endif /* __SDHCI_UHS2_H */
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index a9f5449bddcc..e2dfc7767bcf 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1215,11 +1215,12 @@ static int sdhci_external_dma_init(struct sdhci_host *host)
> return ret;
> }
>
> -static struct dma_chan *sdhci_external_dma_channel(struct sdhci_host *host,
> - struct mmc_data *data)
> +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;
> }
> +EXPORT_SYMBOL_GPL(sdhci_external_dma_channel);
>
> int sdhci_external_dma_setup(struct sdhci_host *host, struct mmc_command *cmd)
> {
> @@ -1466,7 +1467,7 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
> sdhci_writew(host, mode, SDHCI_TRANSFER_MODE);
> }
>
> -static bool sdhci_needs_reset(struct sdhci_host *host, struct mmc_request *mrq)
> +bool sdhci_needs_reset(struct sdhci_host *host, struct mmc_request *mrq)
> {
> return (!(host->flags & SDHCI_DEVICE_DEAD) &&
> ((mrq->cmd && mrq->cmd->error) ||
> @@ -1474,8 +1475,9 @@ static bool sdhci_needs_reset(struct sdhci_host *host, struct mmc_request *mrq)
> (mrq->data && mrq->data->stop && mrq->data->stop->error) ||
> (host->quirks & SDHCI_QUIRK_RESET_AFTER_REQUEST)));
> }
> +EXPORT_SYMBOL_GPL(sdhci_needs_reset);
>
> -static void sdhci_set_mrq_done(struct sdhci_host *host, struct mmc_request *mrq)
> +void sdhci_set_mrq_done(struct sdhci_host *host, struct mmc_request *mrq)
> {
> int i;
>
> @@ -1495,6 +1497,7 @@ static void sdhci_set_mrq_done(struct sdhci_host *host, struct mmc_request *mrq)
>
> WARN_ON(i >= SDHCI_MAX_MRQS);
> }
> +EXPORT_SYMBOL_GPL(sdhci_set_mrq_done);
>
> void __sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq)
> {
> @@ -3029,7 +3032,56 @@ static const struct mmc_host_ops sdhci_ops = {
> * *
> \*****************************************************************************/
>
> -static bool sdhci_request_done(struct sdhci_host *host)
> +void sdhci_request_done_dma(struct sdhci_host *host, struct mmc_request *mrq)
> +{
> + struct mmc_data *data = mrq->data;
> +
> + if (data && data->host_cookie == COOKIE_MAPPED) {
> + if (host->bounce_buffer) {
> + /*
> + * On reads, copy the bounced data into the
> + * sglist
> + */
> + if (mmc_get_dma_dir(data) == DMA_FROM_DEVICE) {
> + unsigned int length = data->bytes_xfered;
> +
> + if (length > host->bounce_buffer_size) {
> + pr_err("%s: bounce buffer is %u bytes but DMA claims to have transferred %u bytes\n",
> + mmc_hostname(host->mmc),
> + host->bounce_buffer_size,
> + data->bytes_xfered);
> + /* Cap it down and continue */
> + length = host->bounce_buffer_size;
> + }
> + dma_sync_single_for_cpu(
> + host->mmc->parent,
> + host->bounce_addr,
> + host->bounce_buffer_size,
> + DMA_FROM_DEVICE);
> + sg_copy_from_buffer(data->sg,
> + data->sg_len,
> + host->bounce_buffer,
> + length);
> + } else {
> + /* No copying, just switch ownership */
> + dma_sync_single_for_cpu(
> + host->mmc->parent,
> + host->bounce_addr,
> + host->bounce_buffer_size,
> + mmc_get_dma_dir(data));
> + }
> + } else {
> + /* Unmap the raw data */
> + dma_unmap_sg(mmc_dev(host->mmc), data->sg,
> + data->sg_len,
> + mmc_get_dma_dir(data));
> + }
> + data->host_cookie = COOKIE_UNMAPPED;
> + }
> +}
> +EXPORT_SYMBOL_GPL(sdhci_request_done_dma);
> +
> +bool sdhci_request_done(struct sdhci_host *host)
> {
> unsigned long flags;
> struct mmc_request *mrq;
> @@ -3067,48 +3119,7 @@ static bool sdhci_request_done(struct sdhci_host *host)
> sdhci_set_mrq_done(host, mrq);
> }
>
> - if (data && data->host_cookie == COOKIE_MAPPED) {
> - if (host->bounce_buffer) {
> - /*
> - * On reads, copy the bounced data into the
> - * sglist
> - */
> - if (mmc_get_dma_dir(data) == DMA_FROM_DEVICE) {
> - unsigned int length = data->bytes_xfered;
> -
> - if (length > host->bounce_buffer_size) {
> - pr_err("%s: bounce buffer is %u bytes but DMA claims to have transferred %u bytes\n",
> - mmc_hostname(host->mmc),
> - host->bounce_buffer_size,
> - data->bytes_xfered);
> - /* Cap it down and continue */
> - length = host->bounce_buffer_size;
> - }
> - dma_sync_single_for_cpu(
> - host->mmc->parent,
> - host->bounce_addr,
> - host->bounce_buffer_size,
> - DMA_FROM_DEVICE);
> - sg_copy_from_buffer(data->sg,
> - data->sg_len,
> - host->bounce_buffer,
> - length);
> - } else {
> - /* No copying, just switch ownership */
> - dma_sync_single_for_cpu(
> - host->mmc->parent,
> - host->bounce_addr,
> - host->bounce_buffer_size,
> - mmc_get_dma_dir(data));
> - }
> - } else {
> - /* Unmap the raw data */
> - dma_unmap_sg(mmc_dev(host->mmc), data->sg,
> - data->sg_len,
> - mmc_get_dma_dir(data));
> - }
> - data->host_cookie = COOKIE_UNMAPPED;
> - }
> + sdhci_request_done_dma(host, mrq);
> }
>
> /*
> @@ -3132,8 +3143,10 @@ static bool sdhci_request_done(struct sdhci_host *host)
> /* This is to force an update */
> host->ops->set_clock(host, host->clock);
>
> - /* Spec says we should do both at the same time, but Ricoh
> - controllers do not like that. */
> + /*
> + * Spec says we should do both at the same time, but
> + * Ricoh controllers do not like that.
> + */
> sdhci_do_reset(host, SDHCI_RESET_CMD);
> sdhci_do_reset(host, SDHCI_RESET_DATA);
>
> @@ -3151,6 +3164,7 @@ static bool sdhci_request_done(struct sdhci_host *host)
>
> return false;
> }
> +EXPORT_SYMBOL_GPL(sdhci_request_done);
>
> static void sdhci_complete_work(struct work_struct *work)
> {
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 6eeb74741da3..74572b54ec47 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -845,8 +845,12 @@ void __sdhci_external_dma_prepare_data(struct sdhci_host *host,
> struct mmc_command *cmd);
> void sdhci_external_dma_pre_transfer(struct sdhci_host *host,
> struct mmc_command *cmd);
> +struct dma_chan *sdhci_external_dma_channel(struct sdhci_host *host,
> + struct mmc_data *data);
> #endif
> bool sdhci_manual_cmd23(struct sdhci_host *host, struct mmc_request *mrq);
> +bool sdhci_needs_reset(struct sdhci_host *host, struct mmc_request *mrq);
> +void sdhci_set_mrq_done(struct sdhci_host *host, struct mmc_request *mrq);
> void __sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq);
> void sdhci_finish_mrq(struct sdhci_host *host, struct mmc_request *mrq);
> void __sdhci_finish_data_common(struct sdhci_host *host);
> @@ -878,6 +882,8 @@ void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios);
> int sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
> struct mmc_ios *ios);
> void sdhci_enable_sdio_irq(struct mmc_host *mmc, int enable);
> +void sdhci_request_done_dma(struct sdhci_host *host, struct mmc_request *mrq);
> +bool sdhci_request_done(struct sdhci_host *host);
> void sdhci_adma_write_desc(struct sdhci_host *host, void **desc,
> dma_addr_t addr, int len, unsigned int cmd);
>
>