[RFC,1/5] soc: qcom: Make the Qualcomm UFS/SDCC ICE a dedicated driver

This takes the already existing duplicated support in both ufs-qcom
and sdhci-msm drivers and makes it a dedicated driver that can be used
by both mentioned drivers. The reason for this is because, staring with
SM8550, the ICE IP block is shared between UFS and SDCC, which means we
need to probe a dedicated device and share it between those two
consumers. So let's add the ICE dedicated driver as a soc driver.

Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
---
 drivers/soc/qcom/Kconfig    |  10 ++
 drivers/soc/qcom/Makefile   |   1 +
 drivers/soc/qcom/qcom-ice.c | 315 ++++++++++++++++++++++++++++++++++++
 include/soc/qcom/ice.h      |  61 +++++++
 4 files changed, 387 insertions(+)
 create mode 100644 drivers/soc/qcom/qcom-ice.c
 create mode 100644 include/soc/qcom/ice.h

On 14.02.2023 13:02, Abel Vesa wrote:
> This takes the already existing duplicated support in both ufs-qcom
> and sdhci-msm drivers and makes it a dedicated driver that can be used
> by both mentioned drivers. The reason for this is because, staring with
> SM8550, the ICE IP block is shared between UFS and SDCC, which means we
> need to probe a dedicated device and share it between those two
> consumers. So let's add the ICE dedicated driver as a soc driver.
> 
> Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
> ---
>  drivers/soc/qcom/Kconfig    |  10 ++
>  drivers/soc/qcom/Makefile   |   1 +
>  drivers/soc/qcom/qcom-ice.c | 315 ++++++++++++++++++++++++++++++++++++
>  include/soc/qcom/ice.h      |  61 +++++++
>  4 files changed, 387 insertions(+)
>  create mode 100644 drivers/soc/qcom/qcom-ice.c
>  create mode 100644 include/soc/qcom/ice.h
> 
> diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
> index a8f283086a21..fa76d3ffb4d3 100644
> --- a/drivers/soc/qcom/Kconfig
> +++ b/drivers/soc/qcom/Kconfig
> @@ -275,4 +275,14 @@ config QCOM_ICC_BWMON
>  	  the fixed bandwidth votes from cpufreq (CPU nodes) thus achieve high
>  	  memory throughput even with lower CPU frequencies.
>  
> +config QCOM_INLINE_CRYPTO_ENGINE
> +	bool "QCOM UFS & SDCC Inline Crypto Engine driver"
> +	depends on ARCH_QCOM || COMPILE_TEST
> +	depends on SCSI_UFS_CRYPTO || MMC_CRYPTO
> +	select QCOM_SCM
> +	help
> +	  Say yes here to support the Qualcomm Inline Crypto Engine driver,
> +	  providing crypto support to Qualcomm storage drivers like UFS
> +	  and SDCC.
> +
>  endmenu
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index 6e88da899f60..30219c164cb0 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -32,3 +32,4 @@ obj-$(CONFIG_QCOM_RPMHPD) += rpmhpd.o
>  obj-$(CONFIG_QCOM_RPMPD) += rpmpd.o
>  obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) +=	kryo-l2-accessors.o
>  obj-$(CONFIG_QCOM_ICC_BWMON)	+= icc-bwmon.o
> +obj-$(CONFIG_QCOM_INLINE_CRYPTO_ENGINE)	+= qcom-ice.o
> diff --git a/drivers/soc/qcom/qcom-ice.c b/drivers/soc/qcom/qcom-ice.c
> new file mode 100644
> index 000000000000..40c9adbc2666
> --- /dev/null
> +++ b/drivers/soc/qcom/qcom-ice.c
> @@ -0,0 +1,315 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Qualcomm ICE (Inline Crypto Engine) support.
> + *
> + * Copyright (c) 2023, Linaro Limited
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/qcom_scm.h>
> +
> +#include <soc/qcom/ice.h>
> +
> +#define AES_256_XTS_KEY_SIZE			64
> +
> +/* QCOM ICE registers */
> +
giga nit: other comments don't have a newline between them and
the defines

> +#define QCOM_ICE_REG_CONTROL			0x0000
> +#define QCOM_ICE_REG_RESET			0x0004
> +#define QCOM_ICE_REG_VERSION			0x0008
> +#define QCOM_ICE_REG_FUSE_SETTING		0x0010
> +#define QCOM_ICE_REG_PARAMETERS_1		0x0014
> +#define QCOM_ICE_REG_PARAMETERS_2		0x0018
> +#define QCOM_ICE_REG_PARAMETERS_3		0x001C
> +#define QCOM_ICE_REG_PARAMETERS_4		0x0020
> +#define QCOM_ICE_REG_PARAMETERS_5		0x0024
> +
> +/* QCOM ICE v3.X only */
> +#define QCOM_ICE_GENERAL_ERR_STTS		0x0040
> +#define QCOM_ICE_INVALID_CCFG_ERR_STTS		0x0030
> +#define QCOM_ICE_GENERAL_ERR_MASK		0x0044
> +
> +/* QCOM ICE v2.X only */
> +#define QCOM_ICE_REG_NON_SEC_IRQ_STTS		0x0040
> +#define QCOM_ICE_REG_NON_SEC_IRQ_MASK		0x0044
> +
> +#define QCOM_ICE_REG_NON_SEC_IRQ_CLR		0x0048
> +#define QCOM_ICE_REG_STREAM1_ERROR_SYNDROME1	0x0050
> +#define QCOM_ICE_REG_STREAM1_ERROR_SYNDROME2	0x0054
> +#define QCOM_ICE_REG_STREAM2_ERROR_SYNDROME1	0x0058
> +#define QCOM_ICE_REG_STREAM2_ERROR_SYNDROME2	0x005C
> +#define QCOM_ICE_REG_STREAM1_BIST_ERROR_VEC	0x0060
> +#define QCOM_ICE_REG_STREAM2_BIST_ERROR_VEC	0x0064
> +#define QCOM_ICE_REG_STREAM1_BIST_FINISH_VEC	0x0068
> +#define QCOM_ICE_REG_STREAM2_BIST_FINISH_VEC	0x006C
> +#define QCOM_ICE_REG_BIST_STATUS		0x0070
> +#define QCOM_ICE_REG_BYPASS_STATUS		0x0074
> +#define QCOM_ICE_REG_ADVANCED_CONTROL		0x1000
> +#define QCOM_ICE_REG_ENDIAN_SWAP		0x1004
> +#define QCOM_ICE_REG_TEST_BUS_CONTROL		0x1010
> +#define QCOM_ICE_REG_TEST_BUS_REG		0x1014
> +
> +/* BIST ("built-in self-test"?) status flags */
> +#define QCOM_ICE_BIST_STATUS_MASK		0xF0000000
GENMASK(31, 28)?

btw, most of these defines seem unused?

> +
> +#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_writel(engine, val, reg)	\
> +	writel((val), (engine)->base + (reg))
> +
> +#define qcom_ice_readl(engine, reg)	\
> +	readl((engine)->base + (reg))
> +
> +/* Only one ICE instance is supported currently by HW */
s/supported currently/currently supported if you meant
"on current SoCs / this driver revision, only one ICE
instance can be running at the same time but that may
change"

or

s/currently/concurrently/ if you meant "only one ICE
instance can be running simultaneously and that won't
change"

> +static struct qcom_ice *engine;
> +
> +static bool qcom_ice_check_supported(struct qcom_ice *ice)
> +{
> +	u32 regval = qcom_ice_readl(ice, QCOM_ICE_REG_VERSION);
> +	struct device *dev = ice->dev;
> +	int major = regval >> 24;
> +	int minor = (regval >> 16) & 0xFF;
> +	int step = regval & 0xFFFF;
FIELD_GET?

> +
> +	ice->supported = true;
> +
> +	/* 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);
> +		ice->supported = false;
> +		goto out;
> +	}
> +
> +	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 = qcom_ice_readl(ice, 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");
> +		ice->supported = false;
> +		goto out;
> +	}
> +out:
> +	return ice->supported;
> +}
> +
> +void qcom_ice_low_power_mode_enable(struct qcom_ice *ice)
> +{
> +	u32 regval;
> +
> +	if (!ice)
> +		return;
> +
> +	regval = qcom_ice_readl(ice, 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
Pardon my ignorance, but I have no idea how this comment corresponds
to the value OR'd..

> +	 */
> +	regval |= 0x7000;
> +	qcom_ice_writel(ice, regval, QCOM_ICE_REG_ADVANCED_CONTROL);
> +}
> +
> +static void qcom_ice_optimization_enable(struct qcom_ice *ice)
> +{
> +	u32 regval;
> +
> +	if (!ice)
> +		return;
> +
> +	/* ICE Optimizations Enable Sequence */
> +	regval = qcom_ice_readl(ice, QCOM_ICE_REG_ADVANCED_CONTROL);
> +	regval |= 0xD807100;
Please use lowercase hex, or de-magic-ify this if you have the means to.

> +	/* ICE HPG requires delay before writing */
> +	udelay(5);
> +	qcom_ice_writel(ice, regval, QCOM_ICE_REG_ADVANCED_CONTROL);
> +	udelay(5);
> +}
> +
> +/* Poll until all BIST bits are reset */
> +static int qcom_ice_wait_bist_status(struct qcom_ice *ice)
> +{
> +	int count;
> +	u32 reg;
> +
> +	if (!ice)
> +		return 0;
> +
> +	for (count = 0; count < 100; count++) {
> +		reg = qcom_ice_readl(ice, QCOM_ICE_REG_BIST_STATUS);
> +		if (!(reg & QCOM_ICE_BIST_STATUS_MASK))
> +			break;
> +		udelay(50);
> +	}
> +
> +	if (reg)
> +		return -ETIMEDOUT;
> +
> +	return 0;
> +}
> +
> +int qcom_ice_resume(struct qcom_ice *ice)
> +{
> +	struct device *dev = ice->dev;
> +	int err;
> +
> +	if (!ice)
> +		return 0;
> +
> +	err = qcom_ice_wait_bist_status(ice);
> +	if (err) {
> +		dev_err(dev, "BIST status error (%d)\n", err);
> +		return err;
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(qcom_ice_resume);
> +
> +int qcom_ice_enable(struct qcom_ice *ice)
> +{
> +	if (!ice)
> +		return 0;
> +
> +	qcom_ice_low_power_mode_enable(ice);
> +	qcom_ice_optimization_enable(ice);
> +
> +	return qcom_ice_resume(ice);
> +}
> +EXPORT_SYMBOL_GPL(qcom_ice_enable);
> +
> +/*
> + * Program a key into a QC ICE keyslot, or evict a keyslot.  QC ICE requires
double space before "QC ICE requires"

> + * vendor-specific SCM calls for this; it doesn't support the standard way.
> + */
> +int qcom_ice_program_key(struct qcom_ice *ice, bool config_enable,
> +			 u8 crypto_cap_idx, u8 algorithm_id,
> +			 u8 key_size, const u8 crypto_key[],
> +			 u8 data_unit_size, int slot)
> +{
> +	struct device *dev = ice->dev;
> +	union {
> +		u8 bytes[AES_256_XTS_KEY_SIZE];
> +		u32 words[AES_256_XTS_KEY_SIZE / sizeof(u32)];
> +	} key;
> +	int i;
> +	int err;
> +
> +	if (!config_enable)
> +		return qcom_scm_ice_invalidate_key(slot);
> +
> +	/* Only AES-256-XTS has been tested so far. */
> +	if (algorithm_id != QCOM_ICE_CRYPTO_ALG_AES_XTS ||
> +	    key_size != QCOM_ICE_CRYPTO_KEY_SIZE_256) {
> +		dev_err_ratelimited(dev,
> +				    "Unhandled crypto capability; algorithm_id=%d, key_size=%d\n",
> +				    algorithm_id, key_size);
> +		return -EINVAL;
> +	}
> +
> +	memcpy(key.bytes, 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,
> +				   data_unit_size);
> +
> +	memzero_explicit(&key, sizeof(key));
> +
> +	return err;
> +}
> +EXPORT_SYMBOL_GPL(qcom_ice_program_key);
> +
> +struct qcom_ice *of_qcom_ice_get(struct device *dev)
> +{
> +	struct qcom_ice *ice = ERR_PTR(-EPROBE_DEFER);
> +	struct device_node *np, *node;
> +
> +	if (!dev || !dev->of_node)
> +		return ERR_PTR(-ENODEV);
> +
> +	np = dev->of_node;
> +
> +	node = of_parse_phandle(np, "qcom,ice", 0);
> +
> +	if (engine && engine->supported)
> +		if (node == engine->np)
> +			ice = engine;
> +
> +	of_node_put(node);
> +
> +	return ice;
> +}
> +EXPORT_SYMBOL_GPL(of_qcom_ice_get);
> +
> +int qcom_ice_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +
> +	if (!qcom_scm_ice_available()) {
> +		dev_warn(dev, "ICE SCM interface not found\n");
> +		return 0;
> +	}
> +
> +	engine = devm_kzalloc(dev, sizeof(*engine), GFP_KERNEL);
> +	if (!engine)
> +		return -ENOMEM;
> +
> +	engine->dev = dev;
> +	engine->np = np;
> +
> +	engine->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(engine->base))
> +		return PTR_ERR(engine->base);
> +
> +	engine->core_clk = devm_clk_get(dev, NULL);
> +	if (IS_ERR(engine->core_clk))
> +		return dev_err_probe(dev, PTR_ERR(engine->core_clk),
> +				     "failed to get core clk\n");
> +
> +	if (!qcom_ice_check_supported(engine))
> +		return -EOPNOTSUPP;
> +
> +	dev_set_drvdata(dev, engine);
> +
> +	dev_info(dev, "Registered Qualcomm Inline Crypto Engine\n");
Not sure if we want two lines informing us about the presence of ICE
(the other one prints the hw version).. dev_dbg, perhaps?

> +
> +	return 0;
> +}
> +
> +static const struct of_device_id qcom_ice_of_match_table[] = {
> +	{
> +		.compatible = "qcom,inline-crypto-engine",
> +	},
I think the common way to go about this is to keep the OF match table
entries in a single line, unless you're adding a long-named match_data
variable, so:

{ .compatible = "qcom,inline-crypto-engine" },

> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, qcom_ice_of_match_table);
> +
> +static struct platform_driver qcom_ice_driver = {
> +	.probe		= qcom_ice_probe,
> +	.driver = {> +		.name	= "qcom-ice",
> +		.of_match_table = qcom_ice_of_match_table,
> +	},
Please use either spaces or tabs, consistently, near the
assignments.

Konrad
> +};
> +
> +module_platform_driver(qcom_ice_driver);
> +
> +MODULE_DESCRIPTION("Qualcomm Inline Crypto Engine driver");
> +MODULE_LICENSE("GPL");
> diff --git a/include/soc/qcom/ice.h b/include/soc/qcom/ice.h
> new file mode 100644
> index 000000000000..3ee8add7aeb9
> --- /dev/null
> +++ b/include/soc/qcom/ice.h
> @@ -0,0 +1,61 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2023, Linaro Limited
> + */
> +
> +#ifndef __QCOM_ICE_H__
> +#define __QCOM_ICE_H__
> +
> +#include <linux/err.h>
> +
> +struct qcom_ice {
> +	struct device *dev;
> +	struct device_node *np;
> +	void __iomem *base;
> +
> +	struct clk *core_clk;
> +
> +	bool supported;
> +};
> +
> +enum qcom_ice_crypto_key_size {
> +	QCOM_ICE_CRYPTO_KEY_SIZE_INVALID	= 0x0,
> +	QCOM_ICE_CRYPTO_KEY_SIZE_128		= 0x1,
> +	QCOM_ICE_CRYPTO_KEY_SIZE_192		= 0x2,
> +	QCOM_ICE_CRYPTO_KEY_SIZE_256		= 0x3,
> +	QCOM_ICE_CRYPTO_KEY_SIZE_512		= 0x4,
> +};
> +
> +enum qcom_ice_crypto_alg {
> +	QCOM_ICE_CRYPTO_ALG_AES_XTS		= 0x0,
> +	QCOM_ICE_CRYPTO_ALG_BITLOCKER_AES_CBC	= 0x1,
> +	QCOM_ICE_CRYPTO_ALG_AES_ECB		= 0x2,
> +	QCOM_ICE_CRYPTO_ALG_ESSIV_AES_CBC	= 0x3,
> +};
> +
> +#if IS_ENABLED(CONFIG_QCOM_INLINE_CRYPTO_ENGINE)
> +int qcom_ice_enable(struct qcom_ice *ice);
> +int qcom_ice_resume(struct qcom_ice *ice);
> +struct qcom_ice *of_qcom_ice_get(struct device *dev);
> +int qcom_ice_program_key(struct qcom_ice *ice, bool config_enable,
> +			 u8 crypto_cap_idx, u8 algorithm_id, u8 key_size,
> +			 const u8 crypto_key[], u8 data_unit_size,
> +			 int slot);
> +#else
> +static int qcom_ice_enable(struct qcom_ice *ice) { return 0; }
> +static int qcom_ice_resume(struct qcom_ice *ice) { return 0; }
> +
> +static struct qcom_ice *of_qcom_ice_get(struct device *dev)
> +{
> +	return ERR_PTR(-EOPNOTSUPP);
> +}
> +
> +int qcom_ice_program_key(struct qcom_ice *ice, bool config_enable,
> +			 u8 crypto_cap_idx, u8 algorithm_id, u8 key_size,
> +			 const u8 crypto_key[], u8 data_unit_size,
> +			 int slot)
> +{
> +	return 0;
> +}
> +#endif /* CONFIG_QCOM_INLINE_CRYPTO_ENGINE */
> +#endif /* __QCOM_ICE_H__ */

Hi Abel,

On Tue, Feb 14, 2023 at 02:02:49PM +0200, Abel Vesa wrote:
> This takes the already existing duplicated support in both ufs-qcom
> and sdhci-msm drivers and makes it a dedicated driver that can be used
> by both mentioned drivers. The reason for this is because, staring with
> SM8550, the ICE IP block is shared between UFS and SDCC, which means we
> need to probe a dedicated device and share it between those two
> consumers. So let's add the ICE dedicated driver as a soc driver.

Thanks for doing this!

About a year ago there was also a patch (that seems to have been abandoned) by
Gaurav Kashyap to create an ICE library:
https://lore.kernel.org/linux-scsi/20211206225725.77512-2-quic_gaurkash@quicinc.com

That patch just made it a library, not an actual device driver.

Is it fair to say that the library approach would not be appropriate anymore for
the reason you mention above: on the latest SoC there's now a single ICE
instance for both the UFS and eMMC host controllers, instead of one per host
controller?

Will there be any issue with using the dedicated driver on older SoCs that do
have separate ICE instances?

Also, in both cases, how will the ICE clock be controlled?  Currently the ICE
clock gets turned on and off by the UFS and eMMC drivers.  I don't see any logic
in your new driver that turns the clock on and off.

> +config QCOM_INLINE_CRYPTO_ENGINE
> +	bool "QCOM UFS & SDCC Inline Crypto Engine driver"

Shouldn't this be a tristate?

Also should it really be user-selectable (have a prompt string)?  There's
already SCSI_UFS_QCOM and MMC_SDHCI_MSM that control the host controller
drivers, and SCSI_UFS_CRYPTO and MMC_CRYPTO that control the inline encryption
support for those host controller drivers.  Shouldn't the kconfig just select
QCOM_INLINE_CRYPTO_ENGINE if 'SCSI_UFS_QCOM && SCSI_UFS_CRYPTO' or
'MMC_SDHCI_MSM && MMC_CRYPTO'?  I don't think there's any need to make users
explicitly select yet another option.

> diff --git a/drivers/soc/qcom/qcom-ice.c b/drivers/soc/qcom/qcom-ice.c
> new file mode 100644
> index 000000000000..40c9adbc2666
> --- /dev/null
> +++ b/drivers/soc/qcom/qcom-ice.c

The directory is already named "qcom", so how about just naming the file
"ice.c"?

> @@ -0,0 +1,315 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Qualcomm ICE (Inline Crypto Engine) support.
> + *
> + * Copyright (c) 2023, Linaro Limited
> + */

Can you please keep the copyright statements from the file this is derived from?

> +/* Only one ICE instance is supported currently by HW */
> +static struct qcom_ice *engine;

Isn't it very bad practice for drivers to store state in static variables like
this?  Sure, the SCM calls are global anyway, so multiple ICE instances aren't
going to be supported regardless.  But surely it isn't necessary to use a static
variable like this too, since the device private data could be used instead?

> +static bool qcom_ice_check_supported(struct qcom_ice *ice)
> +{
> +	u32 regval = qcom_ice_readl(ice, QCOM_ICE_REG_VERSION);
> +	struct device *dev = ice->dev;
> +	int major = regval >> 24;
> +	int minor = (regval >> 16) & 0xFF;
> +	int step = regval & 0xFFFF;
> +
> +	ice->supported = true;
> +
> +	/* 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);
> +		ice->supported = false;
> +		goto out;
> +	}
> +
> +	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 = qcom_ice_readl(ice, 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");
> +		ice->supported = false;
> +		goto out;
> +	}
> +out:
> +	return ice->supported;
> +}

Is the 'supported' field necessary?  Shouldn't the driver just not bind to the
device if it doesn't support it?

> +void qcom_ice_low_power_mode_enable(struct qcom_ice *ice)
> +{

Please make functions static whenever possible.

> +/* Poll until all BIST bits are reset */
> +static int qcom_ice_wait_bist_status(struct qcom_ice *ice)
> +{
> +	int count;
> +	u32 reg;
> +
> +	if (!ice)
> +		return 0;
> +
> +	for (count = 0; count < 100; count++) {
> +		reg = qcom_ice_readl(ice, QCOM_ICE_REG_BIST_STATUS);
> +		if (!(reg & QCOM_ICE_BIST_STATUS_MASK))
> +			break;
> +		udelay(50);
> +	}
> +
> +	if (reg)
> +		return -ETIMEDOUT;
> +
> +	return 0;
> +}

The version of this function in drivers/mmc/host/sdhci-msm.c has a better
comment, and a simpler implementation using readl_poll_timeout().  How about
using that version of this function?

> +int qcom_ice_resume(struct qcom_ice *ice)
> +{
> +	struct device *dev = ice->dev;
> +	int err;
> +
> +	if (!ice)
> +		return 0;

The above NULL check occurs after the pointer was already dereferenced.

Also, why is NULL allowed here anyway?

> +/*
> + * 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.
> + */
> +int qcom_ice_program_key(struct qcom_ice *ice, bool config_enable,
> +			 u8 crypto_cap_idx, u8 algorithm_id,
> +			 u8 key_size, const u8 crypto_key[],
> +			 u8 data_unit_size, int slot)
> +{
> +	struct device *dev = ice->dev;
> +	union {
> +		u8 bytes[AES_256_XTS_KEY_SIZE];
> +		u32 words[AES_256_XTS_KEY_SIZE / sizeof(u32)];
> +	} key;
> +	int i;
> +	int err;
> +
> +	if (!config_enable)
> +		return qcom_scm_ice_invalidate_key(slot);

Can you please make eviction a separate function?  All it needs is the ICE
instance and the keyslot, not the other parameters.

Yes, the UFS and eMMC drivers have the program_key method that does both
programming and eviction, but that doesn't mean this has to do the same.

> diff --git a/include/soc/qcom/ice.h b/include/soc/qcom/ice.h
> new file mode 100644
> index 000000000000..3ee8add7aeb9
> --- /dev/null
> +++ b/include/soc/qcom/ice.h
> @@ -0,0 +1,61 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2023, Linaro Limited
> + */
> +
> +#ifndef __QCOM_ICE_H__
> +#define __QCOM_ICE_H__
> +
> +#include <linux/err.h>
> +
> +struct qcom_ice {
> +	struct device *dev;
> +	struct device_node *np;
> +	void __iomem *base;
> +
> +	struct clk *core_clk;
> +
> +	bool supported;
> +};

Shouldn't struct qcom_ice be private to the driver?

> +enum qcom_ice_crypto_key_size {
> +	QCOM_ICE_CRYPTO_KEY_SIZE_INVALID	= 0x0,
> +	QCOM_ICE_CRYPTO_KEY_SIZE_128		= 0x1,
> +	QCOM_ICE_CRYPTO_KEY_SIZE_192		= 0x2,
> +	QCOM_ICE_CRYPTO_KEY_SIZE_256		= 0x3,
> +	QCOM_ICE_CRYPTO_KEY_SIZE_512		= 0x4,
> +};
> +
> +enum qcom_ice_crypto_alg {
> +	QCOM_ICE_CRYPTO_ALG_AES_XTS		= 0x0,
> +	QCOM_ICE_CRYPTO_ALG_BITLOCKER_AES_CBC	= 0x1,
> +	QCOM_ICE_CRYPTO_ALG_AES_ECB		= 0x2,
> +	QCOM_ICE_CRYPTO_ALG_ESSIV_AES_CBC	= 0x3,
> +};

This patch series introduces an implicit assumption that these values match the
UFS and eMMC algorithm constants.

The way it worked previously is that the UFS driver explicitly checked that the
UFS algorithm ID was AES-256-XTS before translating it into
QCOM_SCM_ICE_CIPHER_AES_256_XTS, and similarly for eMMC.

Now there are these intermediate QCOM_ICE_CRYPTO_ALG_* constants, and there's no
explicit validation that they actually match the UFS and eMMC constants.

Maybe this part should be kept more similar to how it was before, where the
check for AES-256-XTS happens in the UFS and eMMC drivers?

- Eric

On Tue, Feb 14, 2023 at 02:34:47PM +0100, Konrad Dybcio wrote:
> > +#define QCOM_ICE_BIST_STATUS_MASK		0xF0000000
> GENMASK(31, 28)?

I personally think the plain number is much easier to read...

> btw, most of these defines seem unused?

Yes, the unused definitions can be dropped if people prefer.  I only included
them in the original version because this hardware has no public documentation,
so maybe it's helpful to see what registers and fields are available.

I suppose that downstream code could always be dug up if needed, though.  Or
maybe someday there will actually be documentation?

> > +static struct qcom_ice *engine;
> > +
> > +static bool qcom_ice_check_supported(struct qcom_ice *ice)
> > +{
> > +	u32 regval = qcom_ice_readl(ice, QCOM_ICE_REG_VERSION);
> > +	struct device *dev = ice->dev;
> > +	int major = regval >> 24;
> > +	int minor = (regval >> 16) & 0xFF;
> > +	int step = regval & 0xFFFF;
> FIELD_GET?

Similarly, plain bit operations are much more universally understood...

> > +	regval = qcom_ice_readl(ice, 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
> Pardon my ignorance, but I have no idea how this comment corresponds
> to the value OR'd..
> 
> > +	 */
> > +	regval |= 0x7000;
> > +	qcom_ice_writel(ice, regval, QCOM_ICE_REG_ADVANCED_CONTROL);

I'm not sure either!  I've never had access to any documentation for this
hardware, so the above logic is just taken from downstream code.  I kept that
comment because it was the only available explanation for the value OR'd.

Since it doesn't seem to be useful, I'm fine with just removing it.  (But please
keep the "Enable low power mode sequence" part, as that's useful.)

My guess is that it is actually just describing the bits backwards, so [3]-E
corresponds to the three bits that are set.

> > +static void qcom_ice_optimization_enable(struct qcom_ice *ice)
> > +{
> > +	u32 regval;
> > +
> > +	if (!ice)
> > +		return;
> > +
> > +	/* ICE Optimizations Enable Sequence */
> > +	regval = qcom_ice_readl(ice, QCOM_ICE_REG_ADVANCED_CONTROL);
> > +	regval |= 0xD807100;
> Please use lowercase hex, or de-magic-ify this if you have the means to.

I don't know what the 0xD807100 value means, sorry :-(  This is just the value
that works to enable the "optimizations", and which the downstream code was
using.  If anyone has access to the ICE hardware documentation (if there even
*is* documentation), they might be able to say.

- Eric

On 23-02-15 23:22:49, Eric Biggers wrote:
> Hi Abel,
> 
> On Tue, Feb 14, 2023 at 02:02:49PM +0200, Abel Vesa wrote:
> > This takes the already existing duplicated support in both ufs-qcom
> > and sdhci-msm drivers and makes it a dedicated driver that can be used
> > by both mentioned drivers. The reason for this is because, staring with
> > SM8550, the ICE IP block is shared between UFS and SDCC, which means we
> > need to probe a dedicated device and share it between those two
> > consumers. So let's add the ICE dedicated driver as a soc driver.
> 
> Thanks for doing this!
> 
> About a year ago there was also a patch (that seems to have been abandoned) by
> Gaurav Kashyap to create an ICE library:
> https://lore.kernel.org/linux-scsi/20211206225725.77512-2-quic_gaurkash@quicinc.com
> 
> That patch just made it a library, not an actual device driver.
> 
> Is it fair to say that the library approach would not be appropriate anymore for
> the reason you mention above: on the latest SoC there's now a single ICE
> instance for both the UFS and eMMC host controllers, instead of one per host
> controller?

Yes, with SM8550, the same ICE instance is shared, therefore, the
library approach is not enough here. New driver is though.

> 
> Will there be any issue with using the dedicated driver on older SoCs that do
> have separate ICE instances?

Nope. You can have separate devicetree nodes for each instance and
they'll probe fine with the v2 of this patchset.

> 
> Also, in both cases, how will the ICE clock be controlled?  Currently the ICE
> clock gets turned on and off by the UFS and eMMC drivers.  I don't see any logic
> in your new driver that turns the clock on and off.

I added clock enablement in v2. We can decide later on if the clocks
need to be disabled and when.

> 
> > +config QCOM_INLINE_CRYPTO_ENGINE
> > +	bool "QCOM UFS & SDCC Inline Crypto Engine driver"
> 
> Shouldn't this be a tristate?

Changed to tristate in v2.

> 
> Also should it really be user-selectable (have a prompt string)?  There's
> already SCSI_UFS_QCOM and MMC_SDHCI_MSM that control the host controller
> drivers, and SCSI_UFS_CRYPTO and MMC_CRYPTO that control the inline encryption
> support for those host controller drivers.  Shouldn't the kconfig just select
> QCOM_INLINE_CRYPTO_ENGINE if 'SCSI_UFS_QCOM && SCSI_UFS_CRYPTO' or
> 'MMC_SDHCI_MSM && MMC_CRYPTO'?  I don't think there's any need to make users
> explicitly select yet another option.

Made it not user-selectable in v2. See v2 for details.

> 
> > diff --git a/drivers/soc/qcom/qcom-ice.c b/drivers/soc/qcom/qcom-ice.c
> > new file mode 100644
> > index 000000000000..40c9adbc2666
> > --- /dev/null
> > +++ b/drivers/soc/qcom/qcom-ice.c
> 
> The directory is already named "qcom", so how about just naming the file
> "ice.c"?

Renamed to ice.c in v2.

> 
> > @@ -0,0 +1,315 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Qualcomm ICE (Inline Crypto Engine) support.
> > + *
> > + * Copyright (c) 2023, Linaro Limited
> > + */
> 
> Can you please keep the copyright statements from the file this is derived from?

Done, in v2.

> 
> > +/* Only one ICE instance is supported currently by HW */
> > +static struct qcom_ice *engine;
> 
> Isn't it very bad practice for drivers to store state in static variables like
> this?  Sure, the SCM calls are global anyway, so multiple ICE instances aren't
> going to be supported regardless.  But surely it isn't necessary to use a static
> variable like this too, since the device private data could be used instead?

Dropped in v2. Used device private date instead.

> 
> > +static bool qcom_ice_check_supported(struct qcom_ice *ice)
> > +{
> > +	u32 regval = qcom_ice_readl(ice, QCOM_ICE_REG_VERSION);
> > +	struct device *dev = ice->dev;
> > +	int major = regval >> 24;
> > +	int minor = (regval >> 16) & 0xFF;
> > +	int step = regval & 0xFFFF;
> > +
> > +	ice->supported = true;
> > +
> > +	/* 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);
> > +		ice->supported = false;
> > +		goto out;
> > +	}
> > +
> > +	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 = qcom_ice_readl(ice, 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");
> > +		ice->supported = false;
> > +		goto out;
> > +	}
> > +out:
> > +	return ice->supported;
> > +}
> 
> Is the 'supported' field necessary?  Shouldn't the driver just not bind to the
> device if it doesn't support it?

Dropped in v2.

> 
> > +void qcom_ice_low_power_mode_enable(struct qcom_ice *ice)
> > +{
> 
> Please make functions static whenever possible.


Done, in v2.

> 
> > +/* Poll until all BIST bits are reset */
> > +static int qcom_ice_wait_bist_status(struct qcom_ice *ice)
> > +{
> > +	int count;
> > +	u32 reg;
> > +
> > +	if (!ice)
> > +		return 0;
> > +
> > +	for (count = 0; count < 100; count++) {
> > +		reg = qcom_ice_readl(ice, QCOM_ICE_REG_BIST_STATUS);
> > +		if (!(reg & QCOM_ICE_BIST_STATUS_MASK))
> > +			break;
> > +		udelay(50);
> > +	}
> > +
> > +	if (reg)
> > +		return -ETIMEDOUT;
> > +
> > +	return 0;
> > +}
> 
> The version of this function in drivers/mmc/host/sdhci-msm.c has a better
> comment, and a simpler implementation using readl_poll_timeout().  How about
> using that version of this function?

I agree. Done in v2.

> 
> > +int qcom_ice_resume(struct qcom_ice *ice)
> > +{
> > +	struct device *dev = ice->dev;
> > +	int err;
> > +
> > +	if (!ice)
> > +		return 0;
> 
> The above NULL check occurs after the pointer was already dereferenced.
> 
> Also, why is NULL allowed here anyway?
> 

Actually, if one of the crypto configs are not enabled (MMC or UFS) or
if there is no devicetree phandle to point to an ICE instance, we should
allow the driver to use the API and do nothing if the engine pointer is
NULL. It is more cleaner from consumer driver point of view.

> > +/*
> > + * 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.
> > + */
> > +int qcom_ice_program_key(struct qcom_ice *ice, bool config_enable,
> > +			 u8 crypto_cap_idx, u8 algorithm_id,
> > +			 u8 key_size, const u8 crypto_key[],
> > +			 u8 data_unit_size, int slot)
> > +{
> > +	struct device *dev = ice->dev;
> > +	union {
> > +		u8 bytes[AES_256_XTS_KEY_SIZE];
> > +		u32 words[AES_256_XTS_KEY_SIZE / sizeof(u32)];
> > +	} key;
> > +	int i;
> > +	int err;
> > +
> > +	if (!config_enable)
> > +		return qcom_scm_ice_invalidate_key(slot);
> 
> Can you please make eviction a separate function?  All it needs is the ICE
> instance and the keyslot, not the other parameters.
> 
> Yes, the UFS and eMMC drivers have the program_key method that does both
> programming and eviction, but that doesn't mean this has to do the same.

Done in v2.

> 
> > diff --git a/include/soc/qcom/ice.h b/include/soc/qcom/ice.h
> > new file mode 100644
> > index 000000000000..3ee8add7aeb9
> > --- /dev/null
> > +++ b/include/soc/qcom/ice.h
> > @@ -0,0 +1,61 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Copyright (c) 2023, Linaro Limited
> > + */
> > +
> > +#ifndef __QCOM_ICE_H__
> > +#define __QCOM_ICE_H__
> > +
> > +#include <linux/err.h>
> > +
> > +struct qcom_ice {
> > +	struct device *dev;
> > +	struct device_node *np;
> > +	void __iomem *base;
> > +
> > +	struct clk *core_clk;
> > +
> > +	bool supported;
> > +};
> 
> Shouldn't struct qcom_ice be private to the driver?

Nope. If the QCOM_INLINE_CRYPTO_ENGINE is not set, the consumer still
need to be able to call the ICE API (which in this case does really
nothing). Again, this allows the consumer drivers to keep clean of
unnecessary #ifdefs.

> 
> > +enum qcom_ice_crypto_key_size {
> > +	QCOM_ICE_CRYPTO_KEY_SIZE_INVALID	= 0x0,
> > +	QCOM_ICE_CRYPTO_KEY_SIZE_128		= 0x1,
> > +	QCOM_ICE_CRYPTO_KEY_SIZE_192		= 0x2,
> > +	QCOM_ICE_CRYPTO_KEY_SIZE_256		= 0x3,
> > +	QCOM_ICE_CRYPTO_KEY_SIZE_512		= 0x4,
> > +};
> > +
> > +enum qcom_ice_crypto_alg {
> > +	QCOM_ICE_CRYPTO_ALG_AES_XTS		= 0x0,
> > +	QCOM_ICE_CRYPTO_ALG_BITLOCKER_AES_CBC	= 0x1,
> > +	QCOM_ICE_CRYPTO_ALG_AES_ECB		= 0x2,
> > +	QCOM_ICE_CRYPTO_ALG_ESSIV_AES_CBC	= 0x3,
> > +};
> 
> This patch series introduces an implicit assumption that these values match the
> UFS and eMMC algorithm constants.
> 
> The way it worked previously is that the UFS driver explicitly checked that the
> UFS algorithm ID was AES-256-XTS before translating it into
> QCOM_SCM_ICE_CIPHER_AES_256_XTS, and similarly for eMMC.
> 
> Now there are these intermediate QCOM_ICE_CRYPTO_ALG_* constants, and there's no
> explicit validation that they actually match the UFS and eMMC constants.
> 
> Maybe this part should be kept more similar to how it was before, where the
> check for AES-256-XTS happens in the UFS and eMMC drivers?
> 

Done in v2.

> - Eric