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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 12 months 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There is a newer version of this series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 12 months 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 11 months, 1 week 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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