Re: [PATCH 2/5] firmware: arm_scmi: imx: Add i.MX95 CPU Protocol

[Dan Carpenter <dan.carpenter@linaro.org>]

On Tue, Jan 21, 2025 at 11:08:12PM +0800, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> This protocol allows an agent to start, stop a CPU or set reset vector. It
> is used to manage auxiliary CPUs in an LM (e.g. additional cores in an AP
> cluster).
> 
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/firmware/arm_scmi/vendors/imx/Kconfig      |  13 +-
>  drivers/firmware/arm_scmi/vendors/imx/Makefile     |   1 +
>  drivers/firmware/arm_scmi/vendors/imx/imx-sm-cpu.c | 283 +++++++++++++++++++++
>  include/linux/scmi_imx_protocol.h                  |  10 +
>  4 files changed, 306 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/firmware/arm_scmi/vendors/imx/Kconfig b/drivers/firmware/arm_scmi/vendors/imx/Kconfig
> index 1a936fc87d2350e2a21bccd45dfbeebfa3b90286..9070522510e4d3f3d7276a7581f8676006d20f90 100644
> --- a/drivers/firmware/arm_scmi/vendors/imx/Kconfig
> +++ b/drivers/firmware/arm_scmi/vendors/imx/Kconfig
> @@ -12,6 +12,17 @@ config IMX_SCMI_BBM_EXT
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called imx-sm-bbm.
>  
> +config IMX_SCMI_CPU_EXT
> +	tristate "i.MX SCMI CPU EXTENSION"
> +	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
> +	default y if ARCH_MXC
> +	help
> +	  This enables i.MX System CPU Protocol to manage cpu
> +	  start, stop and etc.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called imx-sm-cpu.
> +
>  config IMX_SCMI_LMM_EXT
>  	tristate "i.MX SCMI LMM EXTENSION"
>  	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
> @@ -21,7 +32,7 @@ config IMX_SCMI_LMM_EXT
>  	  manage Logical Machines boot, shutdown and etc.
>  
>  	  To compile this driver as a module, choose M here: the
> -	  module will be called imx-sm-lmm.
> +	  module will be called imx-sm-cpu.
>  

It's supposed to be called imx-sm-lmm.

>  config IMX_SCMI_MISC_EXT
>  	tristate "i.MX SCMI MISC EXTENSION"
> diff --git a/drivers/firmware/arm_scmi/vendors/imx/Makefile b/drivers/firmware/arm_scmi/vendors/imx/Makefile
> index f39a99ccaf9af757475e8b112d224669444d7ddc..e3a5ea46345c89da1afae25e55698044672b7c28 100644
> --- a/drivers/firmware/arm_scmi/vendors/imx/Makefile
> +++ b/drivers/firmware/arm_scmi/vendors/imx/Makefile
> @@ -1,4 +1,5 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  obj-$(CONFIG_IMX_SCMI_BBM_EXT) += imx-sm-bbm.o
> +obj-$(CONFIG_IMX_SCMI_CPU_EXT) += imx-sm-cpu.o
>  obj-$(CONFIG_IMX_SCMI_LMM_EXT) += imx-sm-lmm.o
>  obj-$(CONFIG_IMX_SCMI_MISC_EXT) += imx-sm-misc.o
> diff --git a/drivers/firmware/arm_scmi/vendors/imx/imx-sm-cpu.c b/drivers/firmware/arm_scmi/vendors/imx/imx-sm-cpu.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..e3f294c2cb69a5b5a916d55984f4a63539937d02
> --- /dev/null
> +++ b/drivers/firmware/arm_scmi/vendors/imx/imx-sm-cpu.c
> @@ -0,0 +1,283 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * System control and Management Interface (SCMI) NXP CPU Protocol
> + *
> + * Copyright 2025 NXP
> + */
> +
> +#include <linux/bits.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/scmi_protocol.h>
> +#include <linux/scmi_imx_protocol.h>
> +
> +#include "../../protocols.h"
> +#include "../../notify.h"
> +
> +#define SCMI_PROTOCOL_SUPPORTED_VERSION		0x10000
> +
> +enum scmi_imx_cpu_protocol_cmd {
> +	SCMI_IMX_CPU_ATTRIBUTES	= 0x3,
> +	SCMI_IMX_CPU_START = 0x4,
> +	SCMI_IMX_CPU_STOP = 0x5,
> +	SCMI_IMX_CPU_RESET_VECTOR_SET = 0x6,
> +	SCMI_IMX_CPU_INFO_GET = 0xC,
> +};
> +
> +struct scmi_imx_cpu_info {
> +	u32 nr_cpu;
> +};
> +
> +#define SCMI_IMX_CPU_PROTO_ATTR_NUM_CPUS(x)  ((x) & 0xFFFF)
> +struct scmi_msg_imx_cpu_protocol_attributes {
> +	__le32 attributes;
> +};
> +
> +struct scmi_msg_imx_cpu_attributes_out {
> +	__le32 attributes;
> +#define	CPU_MAX_NAME	16
> +	u8 name[CPU_MAX_NAME];

char is always unsigned in the kernel these days but strings should
still always be char.  Same thing in patch 1, there were a couple u8
names.

> +};
> +
> +struct scmi_imx_cpu_reset_vector_set_in {
> +	__le32 cpuid;
> +#define	CPU_VEC_FLAGS_RESUME	BIT(31)
> +#define	CPU_VEC_FLAGS_START	BIT(30)
> +#define	CPU_VEC_FLAGS_BOOT	BIT(29)
> +	__le32 flags;
> +	__le32 resetvectorlow;
> +	__le32 resetvectorhigh;
> +};
> +
> +struct scmi_imx_cpu_info_get_out {
> +#define	CPU_RUN_MODE_START	0
> +#define	CPU_RUN_MODE_HOLD	1
> +#define	CPU_RUN_MODE_STOP	2
> +#define	CPU_RUN_MODE_SLEEP	3
> +	__le32 runmode;
> +	__le32 sleepmode;
> +	__le32 resetvectorlow;
> +	__le32 resetvectorhigh;
> +};
> +
> +static int scmi_imx_cpu_validate_cpuid(const struct scmi_protocol_handle *ph,
> +				       u32 cpuid)
> +{
> +	struct scmi_imx_cpu_info *info = ph->get_priv(ph);
> +
> +	if (cpuid >= info->nr_cpu)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +static int scmi_imx_cpu_start(const struct scmi_protocol_handle *ph, u32 cpuid)
> +{
> +	struct scmi_xfer *t;
> +	int ret;
> +
> +	ret = scmi_imx_cpu_validate_cpuid(ph, cpuid);
> +	if (ret)
> +		return ret;
> +
> +	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_CPU_START, sizeof(u32),
> +				      0, &t);
> +	if (ret)
> +		return ret;
> +
> +	put_unaligned_le32(cpuid, t->tx.buf);
> +	ret = ph->xops->do_xfer(ph, t);
> +
> +	ph->xops->xfer_put(ph, t);
> +
> +	return ret;
> +}
> +
> +static int scmi_imx_cpu_stop(const struct scmi_protocol_handle *ph, u32 cpuid)
> +{
> +	struct scmi_xfer *t;
> +	int ret;
> +
> +	ret = scmi_imx_cpu_validate_cpuid(ph, cpuid);
> +	if (ret)
> +		return ret;
> +
> +	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_CPU_STOP, sizeof(u32),
> +				      0, &t);
> +	if (ret)
> +		return ret;
> +
> +	put_unaligned_le32(cpuid, t->tx.buf);
> +	ret = ph->xops->do_xfer(ph, t);
> +
> +	ph->xops->xfer_put(ph, t);
> +
> +	return ret;
> +}
> +
> +static int scmi_imx_cpu_reset_vector_set(const struct scmi_protocol_handle *ph,
> +					 u32 cpuid, u64 vector, bool start,
> +					 bool boot, bool resume)
> +{
> +	struct scmi_imx_cpu_reset_vector_set_in *in;
> +	struct scmi_xfer *t;
> +	int ret;
> +
> +	ret = scmi_imx_cpu_validate_cpuid(ph, cpuid);
> +	if (ret)
> +		return ret;
> +
> +	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_CPU_RESET_VECTOR_SET, sizeof(*in),
> +				      0, &t);
> +	if (ret)
> +		return ret;
> +
> +	in = t->tx.buf;
> +	in->cpuid = cpu_to_le32(cpuid);
> +	in->flags = start ? CPU_VEC_FLAGS_START : 0;
> +	in->flags |= boot ? CPU_VEC_FLAGS_BOOT : 0;
> +	in->flags |= resume ? CPU_VEC_FLAGS_BOOT : 0;

s/CPU_VEC_FLAGS_BOOT/CPU_VEC_FLAGS_RESUME/

> +	in->resetvectorlow = cpu_to_le32(lower_32_bits(vector));
> +	in->resetvectorhigh = cpu_to_le32(upper_32_bits(vector));
> +	ret = ph->xops->do_xfer(ph, t);
> +
> +	ph->xops->xfer_put(ph, t);
> +
> +	return ret;
> +}
> +
> +static int scmi_imx_cpu_started(const struct scmi_protocol_handle *ph, u32 cpuid,
> +				bool *started)
> +{
> +	struct scmi_imx_cpu_info_get_out *out;
> +	struct scmi_xfer *t;
> +	int ret;
> +
> +	*started = false;
> +	ret = scmi_imx_cpu_validate_cpuid(ph, cpuid);
> +	if (ret)
> +		return ret;
> +
> +	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_CPU_INFO_GET, sizeof(u32),
> +				      0, &t);
> +	if (ret)
> +		return ret;
> +
> +	put_unaligned_le32(cpuid, t->tx.buf);
> +	ret = ph->xops->do_xfer(ph, t);
> +	if (!ret) {
> +		out = t->rx.buf;
> +		if ((out->runmode == CPU_RUN_MODE_START) ||
> +		    (out->runmode == CPU_RUN_MODE_SLEEP))
> +			*started = true;
> +	}
> +
> +	ph->xops->xfer_put(ph, t);
> +
> +	return ret;
> +}
> +
> +static const struct scmi_imx_cpu_proto_ops scmi_imx_cpu_proto_ops = {
> +	.cpu_reset_vector_set = scmi_imx_cpu_reset_vector_set,
> +	.cpu_start = scmi_imx_cpu_start,
> +	.cpu_started = scmi_imx_cpu_started,
> +	.cpu_stop = scmi_imx_cpu_stop,
> +};
> +
> +static int scmi_imx_cpu_protocol_attributes_get(const struct scmi_protocol_handle *ph,
> +						struct scmi_imx_cpu_info *info)
> +{
> +	struct scmi_msg_imx_cpu_protocol_attributes *attr;
> +	struct scmi_xfer *t;
> +	int ret;
> +
> +	ret = ph->xops->xfer_get_init(ph, PROTOCOL_ATTRIBUTES, 0,
> +				      sizeof(*attr), &t);
> +	if (ret)
> +		return ret;
> +
> +	attr = t->rx.buf;
> +
> +	ret = ph->xops->do_xfer(ph, t);
> +	if (!ret) {
> +		info->nr_cpu = SCMI_IMX_CPU_PROTO_ATTR_NUM_CPUS(attr->attributes);
> +		dev_info(ph->dev, "i.MX SM CPU: %d cpus\n",
> +			 info->nr_cpu);

This can fit in 80 characters:

		dev_info(ph->dev, "i.MX SM CPU: %d cpus\n", info->nr_cpu);

> +	}
> +
> +	ph->xops->xfer_put(ph, t);
> +
> +	return ret;
> +}
> +
> +static int scmi_imx_cpu_attributes_get(const struct scmi_protocol_handle *ph,
> +				       u32 cpuid, struct scmi_imx_cpu_info *info)

No need to pass the "info" pointer.

> +{
> +	struct scmi_msg_imx_cpu_attributes_out *out;
> +	struct scmi_xfer *t;
> +	int ret;
> +
> +	ret = ph->xops->xfer_get_init(ph, SCMI_IMX_CPU_ATTRIBUTES, sizeof(u32), 0, &t);
> +	if (ret)
> +		return ret;
> +
> +	put_unaligned_le32(cpuid, t->tx.buf);
> +	ret = ph->xops->do_xfer(ph, t);
> +	if (!ret) {
> +		out = t->rx.buf;
> +		dev_info(ph->dev, "i.MX CPU: name: %s\n", out->name);
> +	} else {
> +		dev_err(ph->dev, "i.MX cpu: Failed to get info of cpu(%u)\n", cpuid);
> +	}
> +
> +	ph->xops->xfer_put(ph, t);
> +
> +	return ret;
> +}
> +
> +

Multiple blank lines (checkpatch.pl --strict).

> +static int scmi_imx_cpu_protocol_init(const struct scmi_protocol_handle *ph)
> +{

regards,
dan carpenter