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

Eric Biggers
2020-11-12T19:41:26Z

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>
---
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);
+ }
+ 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 = {
--
2.29.2