| Message ID | 20210511101359.83521-1-ulf.hansson@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] mmc: core: Add support for cache ctrl for SD cards | expand |
> In SD spec v6.x the SD function extension registers for performance > enhancements were introduced. As a part of this an optional internal cache > on the SD card, can be used to improve performance. > > The let the SD card use the cache, the host needs to enable it and manage > flushing of the cache, so let's add support for this. > > Note that for an SD card supporting the cache it's mandatory for it, to > also support the poweroff notification feature. According to the SD spec, > if the cache has been enabled and a poweroff notification is sent to the > card, that implicitly also means that the card should flush its internal > cache. Therefore, dealing with cache flushing for REQ_OP_FLUSH block > requests is sufficient. > > Reviewed-by: Linus Walleij <linus.walleij@linaro.org> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Avri Altman <avri.altman@wdc.com> > --- > > Changes in v2: > - Converted to use the BIT() macro for clarification, as suggested by Linus. > - Reset SD_EXT_PERF_CACHE bit when cache enable fails, as suggested by > Avri. > > Note that: > - I decided to keep the error path when failing to enable the cache. It's > seems more robust, as it's unclear what happens with the SD card at failure. > Additionally, if improvements are needed we can make it on top. > > --- > drivers/mmc/core/mmc_ops.c | 1 + > drivers/mmc/core/mmc_ops.h | 1 + > drivers/mmc/core/sd.c | 100 > +++++++++++++++++++++++++++++++++++++ > include/linux/mmc/card.h | 1 + > 4 files changed, 103 insertions(+) > > diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c > index af423acc4c88..3c58f6d0f482 100644 > --- a/drivers/mmc/core/mmc_ops.c > +++ b/drivers/mmc/core/mmc_ops.c > @@ -456,6 +456,7 @@ static int mmc_busy_cb(void *cb_data, bool *busy) > err = R1_STATUS(status) ? -EIO : 0; > break; > case MMC_BUSY_HPI: > + case MMC_BUSY_EXTR_SINGLE: > break; > default: > err = -EINVAL; > diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h > index c3c1d9c2577e..41ab4f573a31 100644 > --- a/drivers/mmc/core/mmc_ops.h > +++ b/drivers/mmc/core/mmc_ops.h > @@ -14,6 +14,7 @@ enum mmc_busy_cmd { > MMC_BUSY_CMD6, > MMC_BUSY_ERASE, > MMC_BUSY_HPI, > + MMC_BUSY_EXTR_SINGLE, > }; > > struct mmc_host; > diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c > index bd40c682d264..781c1e24308c 100644 > --- a/drivers/mmc/core/sd.c > +++ b/drivers/mmc/core/sd.c > @@ -67,6 +67,7 @@ static const unsigned int sd_au_size[] = { > }) > > #define SD_POWEROFF_NOTIFY_TIMEOUT_MS 2000 > +#define SD_WRITE_EXTR_SINGLE_TIMEOUT_MS 1000 > > struct sd_busy_data { > struct mmc_card *card; > @@ -1287,6 +1288,96 @@ static int sd_read_ext_regs(struct mmc_card > *card) > return err; > } > > +static bool sd_cache_enabled(struct mmc_host *host) > +{ > + return host->card->ext_perf.feature_enabled & SD_EXT_PERF_CACHE; > +} > + > +static int sd_flush_cache(struct mmc_host *host) > +{ > + struct mmc_card *card = host->card; > + u8 *reg_buf, fno, page; > + u16 offset; > + int err; > + > + if (!sd_cache_enabled(host)) > + return 0; > + > + reg_buf = kzalloc(512, GFP_KERNEL); > + if (!reg_buf) > + return -ENOMEM; > + > + /* > + * Set Flush Cache at bit 0 in the performance enhancement register at > + * 261 bytes offset. > + */ > + fno = card->ext_perf.fno; > + page = card->ext_perf.page; > + offset = card->ext_perf.offset + 261; > + > + err = sd_write_ext_reg(card, fno, page, offset, BIT(0)); > + if (err) { > + pr_warn("%s: error %d writing Cache Flush bit\n", > + mmc_hostname(host), err); > + goto out; > + } > + > + err = mmc_poll_for_busy(card, > SD_WRITE_EXTR_SINGLE_TIMEOUT_MS, false, > + MMC_BUSY_EXTR_SINGLE); > + if (err) > + goto out; > + > + /* > + * Read the Flush Cache bit. The card shall reset it, to confirm that > + * it's has completed the flushing of the cache. > + */ > + err = sd_read_ext_reg(card, fno, page, offset, 1, reg_buf); > + if (err) { > + pr_warn("%s: error %d reading Cache Flush bit\n", > + mmc_hostname(host), err); > + goto out; > + } > + > + if (reg_buf[0] & BIT(0)) > + err = -ETIMEDOUT; > +out: > + kfree(reg_buf); > + return err; > +} > + > +static int sd_enable_cache(struct mmc_card *card) > +{ > + u8 *reg_buf; > + int err; > + > + card->ext_perf.feature_enabled &= ~SD_EXT_PERF_CACHE; > + > + reg_buf = kzalloc(512, GFP_KERNEL); > + if (!reg_buf) > + return -ENOMEM; > + > + /* > + * Set Cache Enable at bit 0 in the performance enhancement register at > + * 260 bytes offset. > + */ > + err = sd_write_ext_reg(card, card->ext_perf.fno, card->ext_perf.page, > + card->ext_perf.offset + 260, BIT(0)); > + if (err) { > + pr_warn("%s: error %d writing Cache Enable bit\n", > + mmc_hostname(card->host), err); > + goto out; > + } > + > + err = mmc_poll_for_busy(card, > SD_WRITE_EXTR_SINGLE_TIMEOUT_MS, false, > + MMC_BUSY_EXTR_SINGLE); > + if (!err) > + card->ext_perf.feature_enabled |= SD_EXT_PERF_CACHE; > + > +out: > + kfree(reg_buf); > + return err; > +} > + > /* > * Handle the detection and initialisation of a card. > * > @@ -1442,6 +1533,13 @@ static int mmc_sd_init_card(struct mmc_host > *host, u32 ocr, > goto free_card; > } > > + /* Enable internal SD cache if supported. */ > + if (card->ext_perf.feature_support & SD_EXT_PERF_CACHE) { > + err = sd_enable_cache(card); > + if (err) > + goto free_card; > + } > + > if (host->cqe_ops && !host->cqe_enabled) { > err = host->cqe_ops->cqe_enable(host, card); > if (!err) { > @@ -1694,6 +1792,8 @@ static const struct mmc_bus_ops mmc_sd_ops = { > .alive = mmc_sd_alive, > .shutdown = mmc_sd_suspend, > .hw_reset = mmc_sd_hw_reset, > + .cache_enabled = sd_cache_enabled, > + .flush_cache = sd_flush_cache, > }; > > /* > diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h > index 2867af0635f8..74e6c0624d27 100644 > --- a/include/linux/mmc/card.h > +++ b/include/linux/mmc/card.h > @@ -196,6 +196,7 @@ struct sd_ext_reg { > u8 page; > u16 offset; > u8 rev; > + u8 feature_enabled; > u8 feature_support; > /* Power Management Function. */ > #define SD_EXT_POWER_OFF_NOTIFY (1<<0) > -- > 2.25.1
On Tue, 11 May 2021 at 12:40, Avri Altman <Avri.Altman@wdc.com> wrote: > > > In SD spec v6.x the SD function extension registers for performance > > enhancements were introduced. As a part of this an optional internal cache > > on the SD card, can be used to improve performance. > > > > The let the SD card use the cache, the host needs to enable it and manage > > flushing of the cache, so let's add support for this. > > > > Note that for an SD card supporting the cache it's mandatory for it, to > > also support the poweroff notification feature. According to the SD spec, > > if the cache has been enabled and a poweroff notification is sent to the > > card, that implicitly also means that the card should flush its internal > > cache. Therefore, dealing with cache flushing for REQ_OP_FLUSH block > > requests is sufficient. > > > > Reviewed-by: Linus Walleij <linus.walleij@linaro.org> > > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > Reviewed-by: Avri Altman <avri.altman@wdc.com> Thanks! FYI the SD cache ctrl patches have been applied on next. Kind regards Uffe > > > --- > > > > Changes in v2: > > - Converted to use the BIT() macro for clarification, as suggested by Linus. > > - Reset SD_EXT_PERF_CACHE bit when cache enable fails, as suggested by > > Avri. > > > > Note that: > > - I decided to keep the error path when failing to enable the cache. It's > > seems more robust, as it's unclear what happens with the SD card at failure. > > Additionally, if improvements are needed we can make it on top. > > > > --- > > drivers/mmc/core/mmc_ops.c | 1 + > > drivers/mmc/core/mmc_ops.h | 1 + > > drivers/mmc/core/sd.c | 100 > > +++++++++++++++++++++++++++++++++++++ > > include/linux/mmc/card.h | 1 + > > 4 files changed, 103 insertions(+) > > > > diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c > > index af423acc4c88..3c58f6d0f482 100644 > > --- a/drivers/mmc/core/mmc_ops.c > > +++ b/drivers/mmc/core/mmc_ops.c > > @@ -456,6 +456,7 @@ static int mmc_busy_cb(void *cb_data, bool *busy) > > err = R1_STATUS(status) ? -EIO : 0; > > break; > > case MMC_BUSY_HPI: > > + case MMC_BUSY_EXTR_SINGLE: > > break; > > default: > > err = -EINVAL; > > diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h > > index c3c1d9c2577e..41ab4f573a31 100644 > > --- a/drivers/mmc/core/mmc_ops.h > > +++ b/drivers/mmc/core/mmc_ops.h > > @@ -14,6 +14,7 @@ enum mmc_busy_cmd { > > MMC_BUSY_CMD6, > > MMC_BUSY_ERASE, > > MMC_BUSY_HPI, > > + MMC_BUSY_EXTR_SINGLE, > > }; > > > > struct mmc_host; > > diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c > > index bd40c682d264..781c1e24308c 100644 > > --- a/drivers/mmc/core/sd.c > > +++ b/drivers/mmc/core/sd.c > > @@ -67,6 +67,7 @@ static const unsigned int sd_au_size[] = { > > }) > > > > #define SD_POWEROFF_NOTIFY_TIMEOUT_MS 2000 > > +#define SD_WRITE_EXTR_SINGLE_TIMEOUT_MS 1000 > > > > struct sd_busy_data { > > struct mmc_card *card; > > @@ -1287,6 +1288,96 @@ static int sd_read_ext_regs(struct mmc_card > > *card) > > return err; > > } > > > > +static bool sd_cache_enabled(struct mmc_host *host) > > +{ > > + return host->card->ext_perf.feature_enabled & SD_EXT_PERF_CACHE; > > +} > > + > > +static int sd_flush_cache(struct mmc_host *host) > > +{ > > + struct mmc_card *card = host->card; > > + u8 *reg_buf, fno, page; > > + u16 offset; > > + int err; > > + > > + if (!sd_cache_enabled(host)) > > + return 0; > > + > > + reg_buf = kzalloc(512, GFP_KERNEL); > > + if (!reg_buf) > > + return -ENOMEM; > > + > > + /* > > + * Set Flush Cache at bit 0 in the performance enhancement register at > > + * 261 bytes offset. > > + */ > > + fno = card->ext_perf.fno; > > + page = card->ext_perf.page; > > + offset = card->ext_perf.offset + 261; > > + > > + err = sd_write_ext_reg(card, fno, page, offset, BIT(0)); > > + if (err) { > > + pr_warn("%s: error %d writing Cache Flush bit\n", > > + mmc_hostname(host), err); > > + goto out; > > + } > > + > > + err = mmc_poll_for_busy(card, > > SD_WRITE_EXTR_SINGLE_TIMEOUT_MS, false, > > + MMC_BUSY_EXTR_SINGLE); > > + if (err) > > + goto out; > > + > > + /* > > + * Read the Flush Cache bit. The card shall reset it, to confirm that > > + * it's has completed the flushing of the cache. > > + */ > > + err = sd_read_ext_reg(card, fno, page, offset, 1, reg_buf); > > + if (err) { > > + pr_warn("%s: error %d reading Cache Flush bit\n", > > + mmc_hostname(host), err); > > + goto out; > > + } > > + > > + if (reg_buf[0] & BIT(0)) > > + err = -ETIMEDOUT; > > +out: > > + kfree(reg_buf); > > + return err; > > +} > > + > > +static int sd_enable_cache(struct mmc_card *card) > > +{ > > + u8 *reg_buf; > > + int err; > > + > > + card->ext_perf.feature_enabled &= ~SD_EXT_PERF_CACHE; > > + > > + reg_buf = kzalloc(512, GFP_KERNEL); > > + if (!reg_buf) > > + return -ENOMEM; > > + > > + /* > > + * Set Cache Enable at bit 0 in the performance enhancement register at > > + * 260 bytes offset. > > + */ > > + err = sd_write_ext_reg(card, card->ext_perf.fno, card->ext_perf.page, > > + card->ext_perf.offset + 260, BIT(0)); > > + if (err) { > > + pr_warn("%s: error %d writing Cache Enable bit\n", > > + mmc_hostname(card->host), err); > > + goto out; > > + } > > + > > + err = mmc_poll_for_busy(card, > > SD_WRITE_EXTR_SINGLE_TIMEOUT_MS, false, > > + MMC_BUSY_EXTR_SINGLE); > > + if (!err) > > + card->ext_perf.feature_enabled |= SD_EXT_PERF_CACHE; > > + > > +out: > > + kfree(reg_buf); > > + return err; > > +} > > + > > /* > > * Handle the detection and initialisation of a card. > > * > > @@ -1442,6 +1533,13 @@ static int mmc_sd_init_card(struct mmc_host > > *host, u32 ocr, > > goto free_card; > > } > > > > + /* Enable internal SD cache if supported. */ > > + if (card->ext_perf.feature_support & SD_EXT_PERF_CACHE) { > > + err = sd_enable_cache(card); > > + if (err) > > + goto free_card; > > + } > > + > > if (host->cqe_ops && !host->cqe_enabled) { > > err = host->cqe_ops->cqe_enable(host, card); > > if (!err) { > > @@ -1694,6 +1792,8 @@ static const struct mmc_bus_ops mmc_sd_ops = { > > .alive = mmc_sd_alive, > > .shutdown = mmc_sd_suspend, > > .hw_reset = mmc_sd_hw_reset, > > + .cache_enabled = sd_cache_enabled, > > + .flush_cache = sd_flush_cache, > > }; > > > > /* > > diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h > > index 2867af0635f8..74e6c0624d27 100644 > > --- a/include/linux/mmc/card.h > > +++ b/include/linux/mmc/card.h > > @@ -196,6 +196,7 @@ struct sd_ext_reg { > > u8 page; > > u16 offset; > > u8 rev; > > + u8 feature_enabled; > > u8 feature_support; > > /* Power Management Function. */ > > #define SD_EXT_POWER_OFF_NOTIFY (1<<0) > > -- > > 2.25.1 >
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c index af423acc4c88..3c58f6d0f482 100644 --- a/drivers/mmc/core/mmc_ops.c +++ b/drivers/mmc/core/mmc_ops.c @@ -456,6 +456,7 @@ static int mmc_busy_cb(void *cb_data, bool *busy) err = R1_STATUS(status) ? -EIO : 0; break; case MMC_BUSY_HPI: + case MMC_BUSY_EXTR_SINGLE: break; default: err = -EINVAL; diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h index c3c1d9c2577e..41ab4f573a31 100644 --- a/drivers/mmc/core/mmc_ops.h +++ b/drivers/mmc/core/mmc_ops.h @@ -14,6 +14,7 @@ enum mmc_busy_cmd { MMC_BUSY_CMD6, MMC_BUSY_ERASE, MMC_BUSY_HPI, + MMC_BUSY_EXTR_SINGLE, }; struct mmc_host; diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index bd40c682d264..781c1e24308c 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -67,6 +67,7 @@ static const unsigned int sd_au_size[] = { }) #define SD_POWEROFF_NOTIFY_TIMEOUT_MS 2000 +#define SD_WRITE_EXTR_SINGLE_TIMEOUT_MS 1000 struct sd_busy_data { struct mmc_card *card; @@ -1287,6 +1288,96 @@ static int sd_read_ext_regs(struct mmc_card *card) return err; } +static bool sd_cache_enabled(struct mmc_host *host) +{ + return host->card->ext_perf.feature_enabled & SD_EXT_PERF_CACHE; +} + +static int sd_flush_cache(struct mmc_host *host) +{ + struct mmc_card *card = host->card; + u8 *reg_buf, fno, page; + u16 offset; + int err; + + if (!sd_cache_enabled(host)) + return 0; + + reg_buf = kzalloc(512, GFP_KERNEL); + if (!reg_buf) + return -ENOMEM; + + /* + * Set Flush Cache at bit 0 in the performance enhancement register at + * 261 bytes offset. + */ + fno = card->ext_perf.fno; + page = card->ext_perf.page; + offset = card->ext_perf.offset + 261; + + err = sd_write_ext_reg(card, fno, page, offset, BIT(0)); + if (err) { + pr_warn("%s: error %d writing Cache Flush bit\n", + mmc_hostname(host), err); + goto out; + } + + err = mmc_poll_for_busy(card, SD_WRITE_EXTR_SINGLE_TIMEOUT_MS, false, + MMC_BUSY_EXTR_SINGLE); + if (err) + goto out; + + /* + * Read the Flush Cache bit. The card shall reset it, to confirm that + * it's has completed the flushing of the cache. + */ + err = sd_read_ext_reg(card, fno, page, offset, 1, reg_buf); + if (err) { + pr_warn("%s: error %d reading Cache Flush bit\n", + mmc_hostname(host), err); + goto out; + } + + if (reg_buf[0] & BIT(0)) + err = -ETIMEDOUT; +out: + kfree(reg_buf); + return err; +} + +static int sd_enable_cache(struct mmc_card *card) +{ + u8 *reg_buf; + int err; + + card->ext_perf.feature_enabled &= ~SD_EXT_PERF_CACHE; + + reg_buf = kzalloc(512, GFP_KERNEL); + if (!reg_buf) + return -ENOMEM; + + /* + * Set Cache Enable at bit 0 in the performance enhancement register at + * 260 bytes offset. + */ + err = sd_write_ext_reg(card, card->ext_perf.fno, card->ext_perf.page, + card->ext_perf.offset + 260, BIT(0)); + if (err) { + pr_warn("%s: error %d writing Cache Enable bit\n", + mmc_hostname(card->host), err); + goto out; + } + + err = mmc_poll_for_busy(card, SD_WRITE_EXTR_SINGLE_TIMEOUT_MS, false, + MMC_BUSY_EXTR_SINGLE); + if (!err) + card->ext_perf.feature_enabled |= SD_EXT_PERF_CACHE; + +out: + kfree(reg_buf); + return err; +} + /* * Handle the detection and initialisation of a card. * @@ -1442,6 +1533,13 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr, goto free_card; } + /* Enable internal SD cache if supported. */ + if (card->ext_perf.feature_support & SD_EXT_PERF_CACHE) { + err = sd_enable_cache(card); + if (err) + goto free_card; + } + if (host->cqe_ops && !host->cqe_enabled) { err = host->cqe_ops->cqe_enable(host, card); if (!err) { @@ -1694,6 +1792,8 @@ static const struct mmc_bus_ops mmc_sd_ops = { .alive = mmc_sd_alive, .shutdown = mmc_sd_suspend, .hw_reset = mmc_sd_hw_reset, + .cache_enabled = sd_cache_enabled, + .flush_cache = sd_flush_cache, }; /* diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index 2867af0635f8..74e6c0624d27 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -196,6 +196,7 @@ struct sd_ext_reg { u8 page; u16 offset; u8 rev; + u8 feature_enabled; u8 feature_support; /* Power Management Function. */ #define SD_EXT_POWER_OFF_NOTIFY (1<<0)