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[PATCH v1] mmc: Avoid reprogram all keys to Inline Crypto Engine for MMC runtime suspend resume

Seshu Madhavi Puppala posted 1 patch 10 months, 1 week ago
There is a newer version of this series
drivers/mmc/core/crypto.c    | 2 +-
drivers/mmc/host/sdhci-msm.c | 4 ++++
include/linux/mmc/host.h     | 3 +++
3 files changed, 8 insertions(+), 1 deletion(-)
[PATCH v1] mmc: Avoid reprogram all keys to Inline Crypto Engine for MMC runtime suspend resume
Posted by Seshu Madhavi Puppala 10 months, 1 week ago 
Crypto reprogram all keys is called for each MMC runtime
suspend/resume in current upstream design. If this is implemented
as a non-interruptible call to TEE for security, the cpu core is
blocked for execution while this call executes although the crypto
engine already has the keys. For example, glitches in audio/video
streaming applications have been observed due to this. Add the flag
MMC_CAP2_DONT_REPROGRAM as part of host->caps2 to control reprogramming
keys to crypto engine for socs which dont require this feature.

This patch addresses the following:
- Addresses the comments from:
  https://lore.kernel.org/lkml/20241006135530.17363-3-
  quic_spuppala@quicinc.com/T/#m69c9ab538bd9efd54515646952d0d7d1d7c17690
- Avoids reprogram of keys for Qualcomm SOCs only.
- Ensures reprogram of all keys on host controller reset.

Signed-off-by: Seshu Madhavi Puppala <quic_spuppala@quicinc.com>
Co-developed-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
Signed-off-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
Co-developed-by: Sarthak Garg <quic_sartgarg@quicinc.com>
Signed-off-by: Sarthak Garg <quic_sartgarg@quicinc.com>
---
 drivers/mmc/core/crypto.c    | 2 +-
 drivers/mmc/host/sdhci-msm.c | 4 ++++
 include/linux/mmc/host.h     | 3 +++
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/core/crypto.c b/drivers/mmc/core/crypto.c
index fec4fbf16a5b..d947cd1bbfe3 100644
--- a/drivers/mmc/core/crypto.c
+++ b/drivers/mmc/core/crypto.c
@@ -15,7 +15,7 @@
 void mmc_crypto_set_initial_state(struct mmc_host *host)
 {
 	/* Reset might clear all keys, so reprogram all the keys. */
-	if (host->caps2 & MMC_CAP2_CRYPTO)
+	if (host->caps2 & MMC_CAP2_CRYPTO && !(host->caps2 & MMC_CAP2_DONT_REPROGRAM))
 		blk_crypto_reprogram_all_keys(&host->crypto_profile);
 }
 
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 4610f067faca..52207873e18d 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -1865,6 +1865,7 @@ static int sdhci_msm_ice_init(struct sdhci_msm_host *msm_host,
 	}
 
 	mmc->caps2 |= MMC_CAP2_CRYPTO;
+	mmc->caps2 |= MMC_CAP2_DONT_REPROGRAM;
 	return 0;
 }
 
@@ -2451,6 +2452,9 @@ static int sdhci_msm_gcc_reset(struct device *dev, struct sdhci_host *host)
 	usleep_range(200, 210);
 	reset_control_put(reset);
 
+	if (host->mmc->caps2 & MMC_CAP2_CRYPTO)
+		blk_crypto_reprogram_all_keys(&host->mmc->crypto_profile);
+
 	return ret;
 }
 
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 68f09a955a90..d1e6fafca21c 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -459,6 +459,9 @@ struct mmc_host {
 #define MMC_CAP2_CRYPTO		0
 #endif
 #define MMC_CAP2_ALT_GPT_TEGRA	(1 << 28)	/* Host with eMMC that has GPT entry at a non-standard location */
+#ifdef CONFIG_MMC_CRYPTO
+#define MMC_CAP2_DONT_REPROGRAM	(1 << 29)
+#endif
 
 	bool			uhs2_sd_tran;	/* UHS-II flag for SD_TRAN state */
 	bool			uhs2_app_cmd;	/* UHS-II flag for APP command */
-- 
2.17.1
Re: [PATCH v1] mmc: Avoid reprogram all keys to Inline Crypto Engine for MMC runtime suspend resume
Posted by Adrian Hunter 9 months, 2 weeks ago 
On 11/02/25 12:08, Seshu Madhavi Puppala wrote:
> Crypto reprogram all keys is called for each MMC runtime
> suspend/resume in current upstream design. If this is implemented
> as a non-interruptible call to TEE for security, the cpu core is
> blocked for execution while this call executes although the crypto
> engine already has the keys. For example, glitches in audio/video
> streaming applications have been observed due to this. Add the flag
> MMC_CAP2_DONT_REPROGRAM as part of host->caps2 to control reprogramming
> keys to crypto engine for socs which dont require this feature.
> 
> This patch addresses the following:
> - Addresses the comments from:
>   https://lore.kernel.org/lkml/20241006135530.17363-3-
>   quic_spuppala@quicinc.com/T/#m69c9ab538bd9efd54515646952d0d7d1d7c17690
> - Avoids reprogram of keys for Qualcomm SOCs only.
> - Ensures reprogram of all keys on host controller reset.
> 
> Signed-off-by: Seshu Madhavi Puppala <quic_spuppala@quicinc.com>
> Co-developed-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
> Signed-off-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
> Co-developed-by: Sarthak Garg <quic_sartgarg@quicinc.com>
> Signed-off-by: Sarthak Garg <quic_sartgarg@quicinc.com>
> ---
>  drivers/mmc/core/crypto.c    | 2 +-
>  drivers/mmc/host/sdhci-msm.c | 4 ++++
>  include/linux/mmc/host.h     | 3 +++
>  3 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/core/crypto.c b/drivers/mmc/core/crypto.c
> index fec4fbf16a5b..d947cd1bbfe3 100644
> --- a/drivers/mmc/core/crypto.c
> +++ b/drivers/mmc/core/crypto.c
> @@ -15,7 +15,7 @@
>  void mmc_crypto_set_initial_state(struct mmc_host *host)
>  {
>  	/* Reset might clear all keys, so reprogram all the keys. */
> -	if (host->caps2 & MMC_CAP2_CRYPTO)
> +	if (host->caps2 & MMC_CAP2_CRYPTO && !(host->caps2 & MMC_CAP2_DONT_REPROGRAM))
>  		blk_crypto_reprogram_all_keys(&host->crypto_profile);
>  }
>  
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 4610f067faca..52207873e18d 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -1865,6 +1865,7 @@ static int sdhci_msm_ice_init(struct sdhci_msm_host *msm_host,
>  	}
>  
>  	mmc->caps2 |= MMC_CAP2_CRYPTO;
> +	mmc->caps2 |= MMC_CAP2_DONT_REPROGRAM;
>  	return 0;
>  }
>  
> @@ -2451,6 +2452,9 @@ static int sdhci_msm_gcc_reset(struct device *dev, struct sdhci_host *host)
>  	usleep_range(200, 210);
>  	reset_control_put(reset);
>  
> +	if (host->mmc->caps2 & MMC_CAP2_CRYPTO)
> +		blk_crypto_reprogram_all_keys(&host->mmc->crypto_profile);
> +
>  	return ret;
>  }
>  
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 68f09a955a90..d1e6fafca21c 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -459,6 +459,9 @@ struct mmc_host {
>  #define MMC_CAP2_CRYPTO		0
>  #endif
>  #define MMC_CAP2_ALT_GPT_TEGRA	(1 << 28)	/* Host with eMMC that has GPT entry at a non-standard location */
> +#ifdef CONFIG_MMC_CRYPTO
> +#define MMC_CAP2_DONT_REPROGRAM	(1 << 29)
> +#endif

The #ifdef is not needed since we probably want drivers
that reference MMC_CAP2_DONT_REPROGRAM to still compile.

Ulf suggested the name MMC_CAP2_CRYPTO_NO_PROG which seems
much better since it contains "CRYPTO"

>  
>  	bool			uhs2_sd_tran;	/* UHS-II flag for SD_TRAN state */
>  	bool			uhs2_app_cmd;	/* UHS-II flag for APP command */

Patchew 2.1-devel-b67e4c2

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