Re: [PATCH 8/8] mmc: sdhci-msm: add Inline Crypto Engine support

Adrian Hunter
2020-12-02T13:57:36Z

On 12/11/20 9:40 pm, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> Add support for Qualcomm Inline Crypto Engine (ICE) to sdhci-msm.
>
> The standard-compliant parts, such as querying the crypto capabilities
> and enabling crypto for individual MMC requests, are already handled by
> cqhci-crypto.c, which itself is wired into the blk-crypto framework.
> However, ICE requires vendor-specific init, enable, and resume logic,
> and it requires that keys be programmed and evicted by vendor-specific
> SMC calls. Make the sdhci-msm driver handle these details.
>
> This is heavily inspired by the similar changes made for UFS, since the
> UFS and eMMC ICE instances are very similar. See commit df4ec2fa7a4d
> ("scsi: ufs-qcom: Add Inline Crypto Engine support").
>
> I tested this on a Sony Xperia 10, which uses the Snapdragon 630 SoC,
> which has basic upstream support. Mainly, I used android-xfstests
> (https://github.com/tytso/xfstests-bld/blob/master/Documentation/android-xfstests.md)
> to run the ext4 and f2fs encryption tests in a Debian chroot:
>
> android-xfstests -c ext4,f2fs -g encrypt -m inlinecrypt
>
> These tests included tests which verify that the on-disk ciphertext is
> identical to that produced by a software implementation. I also
> verified that ICE was actually being used.
>
> Signed-off-by: Eric Biggers <ebiggers@google.com>

Just 2 minor comments below

> ---
> drivers/mmc/host/Kconfig | 1 +
> drivers/mmc/host/sdhci-msm.c | 270 ++++++++++++++++++++++++++++++++++-
> 2 files changed, 267 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 31481c9fcc2ec..2ede2c86f173b 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -544,6 +544,7 @@ config MMC_SDHCI_MSM
> depends on MMC_SDHCI_PLTFM
> select MMC_SDHCI_IO_ACCESSORS
> select MMC_CQHCI
> + select QCOM_SCM if MMC_CRYPTO
> help
> This selects the Secure Digital Host Controller Interface (SDHCI)
> support present in Qualcomm SOCs. The controller supports
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 3451eb3255135..6ce21414d5104 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -13,6 +13,7 @@
> #include <linux/pm_opp.h>
> #include <linux/slab.h>
> #include <linux/iopoll.h>
> +#include <linux/qcom_scm.h>
> #include <linux/regulator/consumer.h>
> #include <linux/interconnect.h>
> #include <linux/pinctrl/consumer.h>
> @@ -256,10 +257,12 @@ struct sdhci_msm_variant_info {
> struct sdhci_msm_host {
> struct platform_device *pdev;
> void __iomem *core_mem; /* MSM SDCC mapped address */
> + void __iomem *ice_mem; /* MSM ICE mapped address (if available) */
> int pwr_irq; /* power irq */
> struct clk *bus_clk; /* SDHC bus voter clock */
> struct clk *xo_clk; /* TCXO clk needed for FLL feature of cm_dll*/
> - struct clk_bulk_data bulk_clks[4]; /* core, iface, cal, sleep clocks */
> + /* core, iface, cal, sleep, and ice clocks */
> + struct clk_bulk_data bulk_clks[5];
> unsigned long clk_rate;
> struct mmc_host *mmc;
> struct opp_table *opp_table;
> @@ -1785,6 +1788,240 @@ static void sdhci_msm_set_clock(struct sdhci_host *host, unsigned int clock)
> __sdhci_msm_set_clock(host, clock);
> }
>
> +/*****************************************************************************\
> + * *
> + * Inline Crypto Engine (ICE) support *
> + * *
> +\*****************************************************************************/
> +
> +#ifdef CONFIG_MMC_CRYPTO
> +
> +#define AES_256_XTS_KEY_SIZE 64
> +
> +/* QCOM ICE registers */
> +
> +#define QCOM_ICE_REG_VERSION 0x0008
> +
> +#define QCOM_ICE_REG_FUSE_SETTING 0x0010
> +#define QCOM_ICE_FUSE_SETTING_MASK 0x1
> +#define QCOM_ICE_FORCE_HW_KEY0_SETTING_MASK 0x2
> +#define QCOM_ICE_FORCE_HW_KEY1_SETTING_MASK 0x4
> +
> +#define QCOM_ICE_REG_BIST_STATUS 0x0070
> +#define QCOM_ICE_BIST_STATUS_MASK 0xF0000000
> +
> +#define QCOM_ICE_REG_ADVANCED_CONTROL 0x1000
> +
> +#define sdhci_msm_ice_writel(host, val, reg) \
> + writel((val), (host)->ice_mem + (reg))
> +#define sdhci_msm_ice_readl(host, reg) \
> + readl((host)->ice_mem + (reg))
> +
> +static bool sdhci_msm_ice_supported(struct sdhci_msm_host *msm_host)
> +{
> + struct device *dev = mmc_dev(msm_host->mmc);
> + u32 regval = sdhci_msm_ice_readl(msm_host, QCOM_ICE_REG_VERSION);
> + int major = regval >> 24;
> + int minor = (regval >> 16) & 0xFF;
> + int step = regval & 0xFFFF;
> +
> + /* For now this driver only supports ICE version 3. */
> + if (major != 3) {
> + dev_warn(dev, "Unsupported ICE version: v%d.%d.%d\n",
> + major, minor, step);
> + return false;
> + }
> +
> + dev_info(dev, "Found QC Inline Crypto Engine (ICE) v%d.%d.%d\n",
> + major, minor, step);
> +
> + /* If fuses are blown, ICE might not work in the standard way. */
> + regval = sdhci_msm_ice_readl(msm_host, QCOM_ICE_REG_FUSE_SETTING);
> + if (regval & (QCOM_ICE_FUSE_SETTING_MASK |
> + QCOM_ICE_FORCE_HW_KEY0_SETTING_MASK |
> + QCOM_ICE_FORCE_HW_KEY1_SETTING_MASK)) {
> + dev_warn(dev, "Fuses are blown; ICE is unusable!\n");
> + return false;
> + }
> + return true;
> +}
> +
> +static inline struct clk *sdhci_msm_ice_get_clk(struct device *dev)
> +{
> + return devm_clk_get(dev, "ice");
> +}
> +
> +static int sdhci_msm_ice_init(struct sdhci_msm_host *msm_host,
> + struct cqhci_host *cq_host)
> +{
> + struct mmc_host *mmc = msm_host->mmc;
> + struct device *dev = mmc_dev(mmc);
> + struct resource *res;
> + int err;
> +
> + if (!(cqhci_readl(cq_host, CQHCI_CAP) & CQHCI_CAP_CS))
> + return 0;
> +
> + res = platform_get_resource_byname(msm_host->pdev, IORESOURCE_MEM,
> + "ice");
> + if (!res) {
> + dev_warn(dev, "ICE registers not found\n");
> + goto disable;
> + }
> +
> + if (!qcom_scm_ice_available()) {
> + dev_warn(dev, "ICE SCM interface not found\n");
> + goto disable;
> + }
> +
> + msm_host->ice_mem = devm_ioremap_resource(dev, res);
> + if (IS_ERR(msm_host->ice_mem)) {
> + err = PTR_ERR(msm_host->ice_mem);
> + dev_err(dev, "Failed to map ICE registers; err=%d\n", err);
> + return err;
> + }
> +
> + if (!sdhci_msm_ice_supported(msm_host))
> + goto disable;
> +
> + mmc->caps2 |= MMC_CAP2_CRYPTO;
> + return 0;
> +
> +disable:
> + dev_warn(dev, "Disabling inline encryption support\n");
> + return 0;
> +}
> +
> +static void sdhci_msm_ice_low_power_mode_enable(struct sdhci_msm_host *msm_host)
> +{
> + u32 regval;
> +
> + regval = sdhci_msm_ice_readl(msm_host, QCOM_ICE_REG_ADVANCED_CONTROL);
> + /*
> + * Enable low power mode sequence
> + * [0]-0, [1]-0, [2]-0, [3]-E, [4]-0, [5]-0, [6]-0, [7]-0
> + */
> + regval |= 0x7000;
> + sdhci_msm_ice_writel(msm_host, regval, QCOM_ICE_REG_ADVANCED_CONTROL);
> +}
> +
> +static void sdhci_msm_ice_optimization_enable(struct sdhci_msm_host *msm_host)
> +{
> + u32 regval;
> +
> + /* ICE Optimizations Enable Sequence */
> + regval = sdhci_msm_ice_readl(msm_host, QCOM_ICE_REG_ADVANCED_CONTROL);
> + regval |= 0xD807100;
> + /* ICE HPG requires delay before writing */
> + udelay(5);
> + sdhci_msm_ice_writel(msm_host, regval, QCOM_ICE_REG_ADVANCED_CONTROL);
> + udelay(5);
> +}
> +
> +/* Poll until all BIST (built-in self test) bits are reset */
> +static int sdhci_msm_ice_wait_bist_status(struct sdhci_msm_host *msm_host)
> +{
> + int count;
> + u32 reg;
> +
> + for (count = 0; count < 100; count++) {
> + reg = sdhci_msm_ice_readl(msm_host, QCOM_ICE_REG_BIST_STATUS);
> + if (!(reg & QCOM_ICE_BIST_STATUS_MASK))
> + break;
> + udelay(50);

usleep_range ?

Also could use read_poll_timeout() here

> + }
> + if (reg) {
> + dev_err(mmc_dev(msm_host->mmc),
> + "Timed out waiting for ICE self-test to complete\n");
> + return -ETIMEDOUT;
> + }
> + return 0;
> +}
> +
> +static void sdhci_msm_ice_enable(struct sdhci_msm_host *msm_host)
> +{
> + if (!(msm_host->mmc->caps2 & MMC_CAP2_CRYPTO))
> + return;
> + sdhci_msm_ice_low_power_mode_enable(msm_host);
> + sdhci_msm_ice_optimization_enable(msm_host);
> + sdhci_msm_ice_wait_bist_status(msm_host);
> +}
> +
> +static int __maybe_unused sdhci_msm_ice_resume(struct sdhci_msm_host *msm_host)
> +{
> + if (!(msm_host->mmc->caps2 & MMC_CAP2_CRYPTO))
> + return 0;
> + return sdhci_msm_ice_wait_bist_status(msm_host);
> +}
> +
> +/*
> + * Program a key into a QC ICE keyslot, or evict a keyslot. QC ICE requires
> + * vendor-specific SCM calls for this; it doesn't support the standard way.
> + */
> +static int sdhci_msm_program_key(struct cqhci_host *cq_host,
> + const union cqhci_crypto_cfg_entry *cfg,
> + int slot)
> +{
> + struct device *dev = mmc_dev(cq_host->mmc);
> + union cqhci_crypto_cap_entry cap;
> + union {
> + u8 bytes[AES_256_XTS_KEY_SIZE];
> + u32 words[AES_256_XTS_KEY_SIZE / sizeof(u32)];
> + } key;
> + int i;
> + int err;
> +
> + if (!(cfg->config_enable & CQHCI_CRYPTO_CONFIGURATION_ENABLE))
> + return qcom_scm_ice_invalidate_key(slot);
> +
> + /* Only AES-256-XTS has been tested so far. */
> + cap = cq_host->crypto_cap_array[cfg->crypto_cap_idx];
> + if (cap.algorithm_id != CQHCI_CRYPTO_ALG_AES_XTS ||
> + cap.key_size != CQHCI_CRYPTO_KEY_SIZE_256) {
> + dev_err_ratelimited(dev,
> + "Unhandled crypto capability; algorithm_id=%d, key_size=%d\n",
> + cap.algorithm_id, cap.key_size);
> + return -EINVAL;
> + }
> +
> + memcpy(key.bytes, cfg->crypto_key, AES_256_XTS_KEY_SIZE);
> +
> + /*
> + * The SCM call byte-swaps the 32-bit words of the key. So we have to
> + * do the same, in order for the final key be correct.
> + */
> + for (i = 0; i < ARRAY_SIZE(key.words); i++)
> + __cpu_to_be32s(&key.words[i]);
> +
> + err = qcom_scm_ice_set_key(slot, key.bytes, AES_256_XTS_KEY_SIZE,
> + QCOM_SCM_ICE_CIPHER_AES_256_XTS,
> + cfg->data_unit_size);
> + memzero_explicit(&key, sizeof(key));
> + return err;
> +}
> +#else /* CONFIG_MMC_CRYPTO */
> +static inline struct clk *sdhci_msm_ice_get_clk(struct device *dev)
> +{
> + return NULL;
> +}
> +
> +static inline int sdhci_msm_ice_init(struct sdhci_msm_host *msm_host,
> + struct cqhci_host *cq_host)
> +{
> + return 0;
> +}
> +
> +static inline void sdhci_msm_ice_enable(struct sdhci_msm_host *msm_host)
> +{
> +}
> +
> +static inline int __maybe_unused
> +sdhci_msm_ice_resume(struct sdhci_msm_host *msm_host)
> +{
> + return 0;
> +}
> +#endif /* !CONFIG_MMC_CRYPTO */
> +
> /*****************************************************************************\
> * *
> * MSM Command Queue Engine (CQE) *
> @@ -1803,6 +2040,16 @@ static u32 sdhci_msm_cqe_irq(struct sdhci_host *host, u32 intmask)
> return 0;
> }
>
> +static void sdhci_msm_cqe_enable(struct mmc_host *mmc)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
> +
> + sdhci_cqe_enable(mmc);
> + sdhci_msm_ice_enable(msm_host);
> +}
> +
> static void sdhci_msm_cqe_disable(struct mmc_host *mmc, bool recovery)
> {
> struct sdhci_host *host = mmc_priv(mmc);
> @@ -1835,8 +2082,11 @@ static void sdhci_msm_cqe_disable(struct mmc_host *mmc, bool recovery)
> }
>
> static const struct cqhci_host_ops sdhci_msm_cqhci_ops = {
> - .enable = sdhci_cqe_enable,
> + .enable = sdhci_msm_cqe_enable,
> .disable = sdhci_msm_cqe_disable,
> +#ifdef CONFIG_MMC_CRYPTO
> + .program_key = sdhci_msm_program_key,
> +#endif
> };
>
> static int sdhci_msm_cqe_add_host(struct sdhci_host *host,
> @@ -1872,6 +2122,10 @@ static int sdhci_msm_cqe_add_host(struct sdhci_host *host,
>
> dma64 = host->flags & SDHCI_USE_64_BIT_DMA;
>
> + ret = sdhci_msm_ice_init(msm_host, cq_host);
> + if (ret)
> + goto cleanup;
> +
> ret = cqhci_init(cq_host, host->mmc, dma64);
> if (ret) {
> dev_err(&pdev->dev, "%s: CQE init: failed (%d)\n",
> @@ -2321,6 +2575,11 @@ static int sdhci_msm_probe(struct platform_device *pdev)
> clk = NULL;
> msm_host->bulk_clks[3].clk = clk;
>
> + clk = sdhci_msm_ice_get_clk(&pdev->dev);
> + if (IS_ERR(clk))
> + clk = NULL;
> + msm_host->bulk_clks[4].clk = clk;
> +
> ret = clk_bulk_prepare_enable(ARRAY_SIZE(msm_host->bulk_clks),
> msm_host->bulk_clks);
> if (ret)
> @@ -2531,12 +2790,15 @@ static __maybe_unused int sdhci_msm_runtime_resume(struct device *dev)
> * Whenever core-clock is gated dynamically, it's needed to
> * restore the SDR DLL settings when the clock is ungated.
> */
> - if (msm_host->restore_dll_config && msm_host->clk_rate)
> + if (msm_host->restore_dll_config && msm_host->clk_rate) {
> ret = sdhci_msm_restore_sdr_dll_config(host);
> + if (ret)
> + return ret;
> + }
>
> dev_pm_opp_set_rate(dev, msm_host->clk_rate);
>
> - return ret;
> + return sdhci_msm_ice_resume(msm_host);
> }
>
> static const struct dev_pm_ops sdhci_msm_pm_ops = {
>