Message-ID: <CY5PR11MB6211128133CF5AEDC50B3968957DA@CY5PR11MB6211.namprd11.prod.outlook.com>
Date: Thu, 19 Jun 2025 07:32:45 +0000
From: "Gupta, Anshuman" <anshuman.gupta@...el.com>
To: "Vivi, Rodrigo" <rodrigo.vivi@...el.com>, "Nilawar, Badal"
	<badal.nilawar@...el.com>, "intel-xe@...ts.freedesktop.org"
	<intel-xe@...ts.freedesktop.org>, "dri-devel@...ts.freedesktop.org"
	<dri-devel@...ts.freedesktop.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, Jani Nikula <jani.nikula@...ux.intel.com>,
	"Usyskin, Alexander" <alexander.usyskin@...el.com>
CC: "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>, "Ceraolo
 Spurio, Daniele" <daniele.ceraolospurio@...el.com>, "jgg@...dia.com"
	<jgg@...dia.com>
Subject: RE: [PATCH v3 02/10] mei: late_bind: add late binding component
 driver



> -----Original Message-----
> From: Nilawar, Badal <badal.nilawar@...el.com>
> Sent: Thursday, June 19, 2025 12:30 AM
> To: intel-xe@...ts.freedesktop.org; dri-devel@...ts.freedesktop.org; linux-
> kernel@...r.kernel.org
> Cc: Gupta, Anshuman <anshuman.gupta@...el.com>; Vivi, Rodrigo
> <rodrigo.vivi@...el.com>; Usyskin, Alexander <alexander.usyskin@...el.com>;
> gregkh@...uxfoundation.org; Ceraolo Spurio, Daniele
> <daniele.ceraolospurio@...el.com>; jgg@...dia.com
> Subject: [PATCH v3 02/10] mei: late_bind: add late binding component driver
> 
> From: Alexander Usyskin <alexander.usyskin@...el.com>
> 
> Add late binding component driver.
> It allows pushing the late binding configuration from, for example, the Xe graphics
> driver to the Intel discrete graphics card's CSE device.
> 
> Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
> Signed-off-by: Badal Nilawar <badal.nilawar@...el.com>
> ---
> v2:
>  - Use generic naming (Jani)
This patch still wrong naming I915_COMPONENT_LATE_BIND.
LATE_BIND will never be supported by i915, it is a wrong prefix.
@Nikula, Jani @Vivi, Rodrigo is it ok use the i915 naming prefix here ?
We can use INTEL_COMPONENT_LATE_BIND here ?

This header include/drm/intel/i915_component.h is used by both XE and i915.
May be a separate series later requires refactoring this header.


>  - Drop xe_late_bind_component struct to move to xe code (Daniele/Sasha)
> v3:
>  - Updated kconfig description
>  - Move CSC late binding specific flags/defines to late_bind_mei_interface.h
> (Daniele)
> v4:
>  - Add match for PCI_CLASS_DISPLAY_OTHER to support headless cards
> (Anshuman)
> ---
>  drivers/misc/mei/Kconfig                    |   1 +
>  drivers/misc/mei/Makefile                   |   1 +
>  drivers/misc/mei/late_bind/Kconfig          |  13 +
>  drivers/misc/mei/late_bind/Makefile         |   9 +
>  drivers/misc/mei/late_bind/mei_late_bind.c  | 264 ++++++++++++++++++++
>  include/drm/intel/i915_component.h          |   1 +
>  include/drm/intel/late_bind_mei_interface.h |  50 ++++
>  7 files changed, 339 insertions(+)
>  create mode 100644 drivers/misc/mei/late_bind/Kconfig
>  create mode 100644 drivers/misc/mei/late_bind/Makefile
>  create mode 100644 drivers/misc/mei/late_bind/mei_late_bind.c
>  create mode 100644 include/drm/intel/late_bind_mei_interface.h
> 
> diff --git a/drivers/misc/mei/Kconfig b/drivers/misc/mei/Kconfig index
> 7575fee96cc6..771becc68095 100644
> --- a/drivers/misc/mei/Kconfig
> +++ b/drivers/misc/mei/Kconfig
> @@ -84,5 +84,6 @@ config INTEL_MEI_VSC
>  source "drivers/misc/mei/hdcp/Kconfig"
>  source "drivers/misc/mei/pxp/Kconfig"
>  source "drivers/misc/mei/gsc_proxy/Kconfig"
> +source "drivers/misc/mei/late_bind/Kconfig"
> 
>  endif
> diff --git a/drivers/misc/mei/Makefile b/drivers/misc/mei/Makefile index
> 6f9fdbf1a495..84bfde888d81 100644
> --- a/drivers/misc/mei/Makefile
> +++ b/drivers/misc/mei/Makefile
> @@ -31,6 +31,7 @@ CFLAGS_mei-trace.o = -I$(src)
>  obj-$(CONFIG_INTEL_MEI_HDCP) += hdcp/
>  obj-$(CONFIG_INTEL_MEI_PXP) += pxp/
>  obj-$(CONFIG_INTEL_MEI_GSC_PROXY) += gsc_proxy/
> +obj-$(CONFIG_INTEL_MEI_LATE_BIND) += late_bind/
> 
>  obj-$(CONFIG_INTEL_MEI_VSC_HW) += mei-vsc-hw.o  mei-vsc-hw-y := vsc-tp.o
> diff --git a/drivers/misc/mei/late_bind/Kconfig
> b/drivers/misc/mei/late_bind/Kconfig
> new file mode 100644
> index 000000000000..65c7180c5678
> --- /dev/null
> +++ b/drivers/misc/mei/late_bind/Kconfig
> @@ -0,0 +1,13 @@
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2025, Intel Corporation. All rights reserved.
> +#
> +config INTEL_MEI_LATE_BIND
> +	tristate "Intel late binding support on ME Interface"
> +	select INTEL_MEI_ME
> +	depends on DRM_XE
> +	help
> +	  MEI Support for Late Binding for Intel graphics card.
> +
> +	  Enables the ME FW interfaces for Late Binding feature,
> +	  allowing loading of firmware for the devices like Fan
> +	  Controller during by Intel Xe driver.
> diff --git a/drivers/misc/mei/late_bind/Makefile
> b/drivers/misc/mei/late_bind/Makefile
> new file mode 100644
> index 000000000000..a0aeda5853f0
> --- /dev/null
> +++ b/drivers/misc/mei/late_bind/Makefile
> @@ -0,0 +1,9 @@
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Copyright (c) 2025, Intel Corporation. All rights reserved.
> +#
> +# Makefile - Late Binding client driver for Intel MEI Bus Driver.
> +
> +subdir-ccflags-y += -I$(srctree)/drivers/misc/mei/
> +
> +obj-$(CONFIG_INTEL_MEI_LATE_BIND) += mei_late_bind.o
> diff --git a/drivers/misc/mei/late_bind/mei_late_bind.c
> b/drivers/misc/mei/late_bind/mei_late_bind.c
> new file mode 100644
> index 000000000000..cb985f32309e
> --- /dev/null
> +++ b/drivers/misc/mei/late_bind/mei_late_bind.c
> @@ -0,0 +1,264 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2025 Intel Corporation  */ #include
> +<drm/drm_connector.h> #include <drm/intel/i915_component.h> #include
> +<drm/intel/late_bind_mei_interface.h>
> +#include <linux/component.h>
> +#include <linux/pci.h>
> +#include <linux/mei_cl_bus.h>
> +#include <linux/module.h>
> +#include <linux/overflow.h>
> +#include <linux/slab.h>
> +#include <linux/uuid.h>
> +
> +#include "mkhi.h"
> +
> +#define GFX_SRV_MKHI_LATE_BINDING_CMD 0x12 #define
> +GFX_SRV_MKHI_LATE_BINDING_RSP (GFX_SRV_MKHI_LATE_BINDING_CMD |
> 0x80)
> +
> +#define LATE_BIND_SEND_TIMEOUT_MSEC 3000 #define
> +LATE_BIND_RECV_TIMEOUT_MSEC 3000
I commented earlier in V2 series as well, is this timeout specific only to LATE BINDING ?
If this is generic timeout for mei_cldev_{send,recv}_timeout(), 
then this marco should be part of standard MEI headers not late binding.
Other consumers of mei_cldev_{send,recv}_timeout() send the timeout input by component-ops callback .

@Shahsa could you please explained that.
> +
> +/**
> + * struct csc_heci_late_bind_req - late binding request
> + * @header: @ref mkhi_msg_hdr
> + * @type: type of the late binding payload
> + * @flags: flags to be passed to the firmware
> + * @reserved: reserved field
> + * @payload_size: size of the payload data in bytes
> + * @payload: data to be sent to the firmware  */ struct
> +csc_heci_late_bind_req {
> +	struct mkhi_msg_hdr header;
> +	u32 type;
> +	u32 flags;
> +	u32 reserved[2];
> +	u32 payload_size;
> +	u8  payload[] __counted_by(payload_size); } __packed;
> +
> +/**
> + * struct csc_heci_late_bind_rsp - late binding response
> + * @header: @ref mkhi_msg_hdr
> + * @type: type of the late binding payload
> + * @reserved: reserved field
> + * @status: status of the late binding command execution by firmware
> +*/ struct csc_heci_late_bind_rsp {
> +	struct mkhi_msg_hdr header;
> +	u32 type;
> +	u32 reserved[2];
> +	u32 status;
> +} __packed;
> +
> +static int mei_late_bind_check_response(const struct device *dev, const
> +struct mkhi_msg_hdr *hdr) {
> +	if (hdr->group_id != MKHI_GROUP_ID_GFX) {
> +		dev_err(dev, "Mismatch group id: 0x%x instead of 0x%x\n",
> +			hdr->group_id, MKHI_GROUP_ID_GFX);
> +		return -EINVAL;
> +	}
> +
> +	if (hdr->command != GFX_SRV_MKHI_LATE_BINDING_RSP) {
> +		dev_err(dev, "Mismatch command: 0x%x instead of 0x%x\n",
> +			hdr->command, GFX_SRV_MKHI_LATE_BINDING_RSP);
> +		return -EINVAL;
> +	}
Why are we not checking mkhi_msg_hdr hdr->result here ?
> +
> +	return 0;
> +}
> +
> +/**
> + * mei_late_bind_push_config - Sends a config to the firmware.
> + * @dev: device struct corresponding to the mei device
> + * @type: payload type
> + * @flags: payload flags
> + * @payload: payload buffer
> + * @payload_size: payload buffer size
> + *
> + * Return: 0 success, negative errno value on transport failure,
> + *         positive status returned by FW
> + */
> +static int mei_late_bind_push_config(struct device *dev, u32 type, u32 flags,
> +				     const void *payload, size_t payload_size) {
> +	struct mei_cl_device *cldev;
> +	struct csc_heci_late_bind_req *req = NULL;
> +	struct csc_heci_late_bind_rsp rsp;
> +	size_t req_size;
> +	int ret;
> +
> +	if (!dev || !payload || !payload_size)
> +		return -EINVAL;
> +
> +	cldev = to_mei_cl_device(dev);
> +
> +	ret = mei_cldev_enable(cldev);
> +	if (ret < 0) {
> +		dev_dbg(dev, "mei_cldev_enable failed. %d\n", ret);
> +		return ret;
> +	}
> +
> +	req_size = struct_size(req, payload, payload_size);
> +	if (req_size > mei_cldev_mtu(cldev)) {
> +		dev_err(dev, "Payload is too big %zu\n", payload_size);
> +		ret = -EMSGSIZE;
> +		goto end;
> +	}
> +
> +	req = kmalloc(req_size, GFP_KERNEL);
> +	if (!req) {
> +		ret = -ENOMEM;
> +		goto end;
> +	}
Use Kzalloc here, to make sure reserved filed of header is zeroed.
> +
> +	req->header.group_id = MKHI_GROUP_ID_GFX;
> +	req->header.command = GFX_SRV_MKHI_LATE_BINDING_CMD;
> +	req->type = type;
> +	req->flags = flags;
> +	req->reserved[0] = 0;
> +	req->reserved[1] = 0;
> +	req->payload_size = payload_size;
> +	memcpy(req->payload, payload, payload_size);
> +
> +	ret = mei_cldev_send_timeout(cldev, (void *)req, req_size,
> LATE_BIND_SEND_TIMEOUT_MSEC);
> +	if (ret < 0) {
> +		dev_err(dev, "mei_cldev_send failed. %d\n", ret);
> +		goto end;
> +	}
> +	ret = mei_cldev_recv_timeout(cldev, (void *)&rsp, sizeof(rsp),
> LATE_BIND_RECV_TIMEOUT_MSEC);
> +	if (ret < 0) {
> +		dev_err(dev, "mei_cldev_recv failed. %d\n", ret);
> +		goto end;
> +	}
> +	ret = mei_late_bind_check_response(dev, &rsp.header);
> +	if (ret) {
> +		dev_err(dev, "bad result response from the firmware: 0x%x\n",
> +			*(uint32_t *)&rsp.header);

> +		goto end;
> +	}
> +	ret = (int)rsp.status;
> +	dev_dbg(dev, "%s status = %d\n", __func__, ret);
AFAIU It would be useful to add the status enum in late_bind_mei_interface.h.
> +
> +end:
> +	mei_cldev_disable(cldev);
> +	kfree(req);
> +	return ret;
> +}
> +
> +static const struct late_bind_component_ops mei_late_bind_ops = {
> +	.owner = THIS_MODULE,
> +	.push_config = mei_late_bind_push_config, };
> +
> +static int mei_component_master_bind(struct device *dev) {
> +	return component_bind_all(dev, (void *)&mei_late_bind_ops); }
> +
> +static void mei_component_master_unbind(struct device *dev) {
> +	component_unbind_all(dev, (void *)&mei_late_bind_ops); }
> +
> +static const struct component_master_ops mei_component_master_ops = {
> +	.bind = mei_component_master_bind,
> +	.unbind = mei_component_master_unbind, };
> +
> +/**
> + * mei_late_bind_component_match - compare function for matching mei late
> bind.
> + *
> + *    The function checks if requested is Intel VGA device
Please modify the Kenel Doc comment here, as per the function.
> + *    and the parent of requester and the grand parent of mei_if are the same
We are matching against the requester not parent of requester.
Modify the Kernel Doc comment properly.
> + *    device.
> + *
> + * @dev: master device
> + * @subcomponent: subcomponent to match (I915_COMPONENT_LATE_BIND)
> + * @data: compare data (mei late-bind bus device)
AFAIK It is mei client device not mei bus device.
> + *
> + * Return:
> + * * 1 - if components match
> + * * 0 - otherwise
> + */
> +static int mei_late_bind_component_match(struct device *dev, int
> subcomponent,
> +					 void *data)
> +{
> +	struct device *base = data;
> +	struct pci_dev *pdev;
> +
> +	if (!dev)
> +		return 0;
> +
> +	if (!dev_is_pci(dev))
> +		return 0;
> +
> +	pdev = to_pci_dev(dev);
> +
> +	if (pdev->vendor != PCI_VENDOR_ID_INTEL)
> +		return 0;
> +
> +	if (pdev->class != (PCI_CLASS_DISPLAY_VGA << 8) ||
> +	    pdev->class != (PCI_CLASS_DISPLAY_OTHER << 8))
> +		return 0;
This condition should be like below,  if I am not missing anything. 
if (pdev->class != (PCI_CLASS_DISPLAY_VGA << 8) &&
 pdev->class != (PCI_CLASS_DISPLAY_OTHER << 8))

Thanks,
Anshuman.
> +
> +	if (subcomponent != I915_COMPONENT_LATE_BIND)
> +		return 0;
> +
> +	base = base->parent;
> +	if (!base) /* mei device */
> +		return 0;
> +
> +	base = base->parent; /* pci device */
> +
> +	return !!base && dev == base;
> +}
> +
> +static int mei_late_bind_probe(struct mei_cl_device *cldev,
> +			       const struct mei_cl_device_id *id) {
> +	struct component_match *master_match = NULL;
> +	int ret;
> +
> +	component_match_add_typed(&cldev->dev, &master_match,
> +				  mei_late_bind_component_match, &cldev-
> >dev);
> +	if (IS_ERR_OR_NULL(master_match))
> +		return -ENOMEM;
> +
> +	ret = component_master_add_with_match(&cldev->dev,
> +					      &mei_component_master_ops,
> +					      master_match);
> +	if (ret < 0)
> +		dev_err(&cldev->dev, "Master comp add failed %d\n", ret);
> +
> +	return ret;
> +}
> +
> +static void mei_late_bind_remove(struct mei_cl_device *cldev) {
> +	component_master_del(&cldev->dev, &mei_component_master_ops); }
> +
> +#define MEI_GUID_MKHI UUID_LE(0xe2c2afa2, 0x3817, 0x4d19, \
> +			      0x9d, 0x95, 0x6, 0xb1, 0x6b, 0x58, 0x8a, 0x5d)
> +
> +static struct mei_cl_device_id mei_late_bind_tbl[] = {
> +	{ .uuid = MEI_GUID_MKHI, .version = MEI_CL_VERSION_ANY },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(mei, mei_late_bind_tbl);
> +
> +static struct mei_cl_driver mei_late_bind_driver = {
> +	.id_table = mei_late_bind_tbl,
> +	.name = KBUILD_MODNAME,
> +	.probe = mei_late_bind_probe,
> +	.remove	= mei_late_bind_remove,
> +};
> +
> +module_mei_cl_driver(mei_late_bind_driver);
> +
> +MODULE_AUTHOR("Intel Corporation");
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("MEI Late Binding");
> diff --git a/include/drm/intel/i915_component.h
> b/include/drm/intel/i915_component.h
> index 4ea3b17aa143..4945044d41e6 100644
> --- a/include/drm/intel/i915_component.h
> +++ b/include/drm/intel/i915_component.h
> @@ -31,6 +31,7 @@ enum i915_component_type {
>  	I915_COMPONENT_HDCP,
>  	I915_COMPONENT_PXP,
>  	I915_COMPONENT_GSC_PROXY,
> +	I915_COMPONENT_LATE_BIND,
>  };
> 
>  /* MAX_PORT is the number of port
> diff --git a/include/drm/intel/late_bind_mei_interface.h
> b/include/drm/intel/late_bind_mei_interface.h
> new file mode 100644
> index 000000000000..2c53657ce91b
> --- /dev/null
> +++ b/include/drm/intel/late_bind_mei_interface.h
> @@ -0,0 +1,50 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright (c) 2025 Intel Corporation  */
> +
> +#ifndef _LATE_BIND_MEI_INTERFACE_H_
> +#define _LATE_BIND_MEI_INTERFACE_H_
> +
> +#include <linux/types.h>
> +
> +struct device;
> +struct module;
> +
> +/**
> + * Late Binding flags
> + * Persistent across warm reset
> + */
> +#define CSC_LATE_BINDING_FLAGS_IS_PERSISTENT	BIT(0)
> +
> +/**
> + * xe_late_bind_fw_type - enum to determine late binding fw type  */
> +enum late_bind_type {
> +	CSC_LATE_BINDING_TYPE_FAN_CONTROL = 1, };
> +
> +/**
> + * struct late_bind_component_ops - ops for Late Binding services.
> + * @owner: Module providing the ops
> + * @push_config: Sends a config to FW.
> + */
> +struct late_bind_component_ops {
> +	struct module *owner;
> +
> +	/**
> +	 * @push_config: Sends a config to FW.
> +	 * @dev: device struct corresponding to the mei device
> +	 * @type: payload type
> +	 * @flags: payload flags
> +	 * @payload: payload buffer
> +	 * @payload_size: payload buffer size
> +	 *
> +	 * Return: 0 success, negative errno value on transport failure,
> +	 *         positive status returned by FW
> +	 */
> +	int (*push_config)(struct device *dev, u32 type, u32 flags,
> +			   const void *payload, size_t payload_size); };
> +
> +#endif /* _LATE_BIND_MEI_INTERFACE_H_ */
> --
> 2.34.1

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