[Intel-gfx] [PATCH v10 5/6] drm/i915/mtl: Add function to send command to GSC CS

Shankar, Uma uma.shankar at intel.com
Mon Mar 6 12:32:47 UTC 2023



> -----Original Message-----
> From: Kandpal, Suraj <suraj.kandpal at intel.com>
> Sent: Wednesday, February 1, 2023 2:38 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: Nautiyal, Ankit K <ankit.k.nautiyal at intel.com>; Kandpal, Suraj
> <suraj.kandpal at intel.com>; Ceraolo Spurio, Daniele
> <daniele.ceraolospurio at intel.com>; Teres Alexis, Alan Previn
> <alan.previn.teres.alexis at intel.com>; Shankar, Uma <uma.shankar at intel.com>;
> Gupta, Anshuman <anshuman.gupta at intel.com>
> Subject: [PATCH v10 5/6] drm/i915/mtl: Add function to send command to GSC CS
> 
> Add function that takes care of sending command to gsc cs. We start of with
> allocation of memory for our command intel_hdcp_gsc_message that contains gsc
> cs memory header as directed in specs followed by the actual payload hdcp message
> that we want to send.
> Spec states that we need to poll pending bit of response header around
> 20 times each try being 50ms apart hence adding that to current gsc_msg_send
> function Also we use the same function to take care of both sending and receiving
> hence no separate function to get the response.
> 
> --v4
> -Create common function to fill in gsc_mtl_header [Alan] -define host session
> bitmask [Alan]
> 
> --v5
> -use i915 directly instead of gt->i915 [Alan] -No need to make fields NULL as we are
> already using kzalloc [Alan]
> 
> --v8
> -change mechanism to reuse the same memory for one hdcp session[Alan] -fix
> header ordering -add comments to explain flags and host session mask [Alan]
> 
> --v9
> -remove gem obj from hdcp message as we can use i915_vma_unpin_and_release
> [Alan] -move hdcp message allocation and deallocation from hdcp2_enable and
> hdcp2_disable to init and teardown of HDCP [Alan]
> 
> --v10
> -remove unnecessary i915_vma_unpin [Alan]
> 
> Cc: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Cc: Alan Pervin Teres <alan.previn.teres.alexis at intel.com>
> Cc: Uma Shankar <uma.shankar at intel.com>
> Cc: Anshuman Gupta <anshuman.gupta at intel.com>
> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> Reviewed-by: Alan Previn <alan.previn.teres.alexis at intel.com>
> ---
>  drivers/gpu/drm/i915/Makefile                 |   1 +
>  .../gpu/drm/i915/display/intel_display_core.h |   5 +
>  drivers/gpu/drm/i915/display/intel_hdcp_gsc.c | 198 ++++++++++++++++++
> drivers/gpu/drm/i915/display/intel_hdcp_gsc.h |  23 ++
> .../i915/gt/uc/intel_gsc_uc_heci_cmd_submit.c |  15 ++
> .../i915/gt/uc/intel_gsc_uc_heci_cmd_submit.h |  16 ++
>  6 files changed, 258 insertions(+)
>  create mode 100644 drivers/gpu/drm/i915/display/intel_hdcp_gsc.c
>  create mode 100644 drivers/gpu/drm/i915/display/intel_hdcp_gsc.h
> 
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index
> 482928cffb1c..ba76bec715af 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -255,6 +255,7 @@ i915-y += \
>  	display/intel_frontbuffer.o \
>  	display/intel_global_state.o \
>  	display/intel_hdcp.o \
> +	display/intel_hdcp_gsc.o \
>  	display/intel_hotplug.o \
>  	display/intel_hti.o \
>  	display/intel_lpe_audio.o \
> diff --git a/drivers/gpu/drm/i915/display/intel_display_core.h
> b/drivers/gpu/drm/i915/display/intel_display_core.h
> index 139100fe2383..20d2a79a5d05 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_core.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_core.h
> @@ -382,6 +382,11 @@ struct intel_display {
>  		struct i915_hdcp_master *master;
>  		bool comp_added;
> 
> +		/*HDCP message struct for allocation of memory which can be
> reused

Fix Comment style.

> +		 * when sending message to gsc cs
> +		 * this is only populated post Meteorlake
> +		 */
> +		struct intel_hdcp_gsc_message *hdcp_message;
>  		/* Mutex to protect the above hdcp component related values. */
>  		struct mutex comp_mutex;
>  	} hdcp;
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c
> b/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c
> new file mode 100644
> index 000000000000..8e3b5e6733d7
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp_gsc.c
> @@ -0,0 +1,198 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright 2023, Intel Corporation.
> + */
> +
> +#include "display/intel_hdcp_gsc.h"
> +#include "gem/i915_gem_region.h"
> +#include "gt/uc/intel_gsc_uc_heci_cmd_submit.h"
> +#include "i915_drv.h"
> +#include "i915_utils.h"
> +
> +/*This function helps allocate memory for the command that we will send
> +to gsc cs */ static int intel_hdcp_gsc_initialize_message(struct drm_i915_private
> *i915,
> +					     struct intel_hdcp_gsc_message
> *hdcp_message) {
> +	struct intel_gt *gt = i915->media_gt;
> +	struct drm_i915_gem_object *obj = NULL;
> +	struct i915_vma *vma = NULL;
> +	void *cmd;
> +	int err;
> +
> +	/* allocate object of one page for HDCP command memory and store it */
> +	obj = i915_gem_object_create_shmem(i915, PAGE_SIZE);
> +
> +	if (IS_ERR(obj)) {
> +		drm_err(&i915->drm, "Failed to allocate HDCP streaming
> command!\n");
> +		return PTR_ERR(obj);
> +	}
> +
> +	cmd = i915_gem_object_pin_map_unlocked(obj,
> i915_coherent_map_type(i915, obj, true));
> +	if (IS_ERR(cmd)) {
> +		drm_err(&i915->drm, "Failed to map gsc message page!\n");
> +		err = PTR_ERR(cmd);
> +		goto out_unpin;
> +	}
> +
> +	vma = i915_vma_instance(obj, &gt->ggtt->vm, NULL);
> +	if (IS_ERR(vma)) {
> +		err = PTR_ERR(vma);
> +		goto out_unmap;
> +	}
> +
> +	err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL);
> +	if (err)
> +		goto out_unmap;
> +
> +	memset(cmd, 0, obj->base.size);
> +
> +	hdcp_message->hdcp_cmd = cmd;
> +	hdcp_message->vma = vma;
> +
> +	return 0;
> +
> +out_unmap:
> +	i915_gem_object_unpin_map(obj);
> +out_unpin:
> +	i915_gem_object_put(obj);
> +	return err;
> +}
> +
> +int intel_hdcp_gsc_hdcp2_init(struct drm_i915_private *i915) {
> +	struct intel_hdcp_gsc_message *hdcp_message;
> +	int ret;
> +
> +	hdcp_message = kzalloc(sizeof(*hdcp_message), GFP_KERNEL);
> +
> +	if (!hdcp_message)
> +		return -ENOMEM;
> +
> +	/* NOTE: No need to lock the comp mutex here as it is already

Fix Comment style.

> +	 * going to be taken before this function called
> +	 */
> +	i915->display.hdcp.hdcp_message = hdcp_message;
> +	ret = intel_hdcp_gsc_initialize_message(i915, hdcp_message);
> +
> +	if (ret)
> +		drm_err(&i915->drm, "Could not initialize hdcp_message\n");
> +
> +	return ret;
> +}
> +
> +void intel_hdcp_gsc_free_message(struct drm_i915_private *i915) {
> +	struct intel_hdcp_gsc_message *hdcp_message =
> +					i915->display.hdcp.hdcp_message;
> +
> +	i915_vma_unpin_and_release(&hdcp_message->vma,
> I915_VMA_RELEASE_MAP);
> +	kfree(hdcp_message);
> +}
> +
> +static int intel_gsc_send_sync(struct drm_i915_private *i915,
> +			       struct intel_gsc_mtl_header *header, u64 addr,
> +			       size_t msg_out_len)
> +{
> +	struct intel_gt *gt = i915->media_gt;
> +	int ret;
> +
> +	header->flags = 0;
> +	ret = intel_gsc_uc_heci_cmd_submit_packet(&gt->uc.gsc, addr,
> +						  header->message_size,
> +						  addr,
> +						  msg_out_len + sizeof(*header));
> +	if (ret) {
> +		drm_err(&i915->drm, "failed to send gsc HDCP msg (%d)\n", ret);
> +		return ret;
> +	}

Leave a line gap.

> +	/*
> +	 * Checking validity marker for memory sanity
> +	 */
> +	if (header->validity_marker != GSC_HECI_VALIDITY_MARKER) {
> +		drm_err(&i915->drm, "invalid validity marker\n");
> +		return -EINVAL;
> +	}
> +
> +	if (header->status != 0) {
> +		drm_err(&i915->drm, "header status indicates error %d\n",
> +			header->status);
> +		return -EINVAL;
> +	}
> +
> +	if (header->flags & GSC_OUTFLAG_MSG_PENDING)
> +		return -EAGAIN;
> +
> +	return 0;
> +}
> +
> +/*
> + * This function can now be used for sending requests and will also
> +handle
> + * receipt of reply messages hence no different function of message
> +retrieval
> + * is required. We will initialize intel_hdcp_gsc_message structure
> +then add
> + * gsc cs memory header as stated in specs after which the normal HDCP
> +payload
> + * will follow
> + */
> +ssize_t intel_hdcp_gsc_msg_send(struct drm_i915_private *i915, u8 *msg_in,
> +				size_t msg_in_len, u8 *msg_out, size_t
> msg_out_len) {
> +	struct intel_gt *gt = i915->media_gt;
> +	struct intel_gsc_mtl_header *header;
> +	const size_t max_msg_size = PAGE_SIZE - sizeof(*header);
> +	struct intel_hdcp_gsc_message *hdcp_message;
> +	u64 addr, host_session_id;
> +	u32 reply_size, msg_size;
> +	int ret, tries = 0;
> +
> +	if (!intel_uc_uses_gsc_uc(&gt->uc))
> +		return -ENODEV;
> +
> +	if (msg_in_len > max_msg_size || msg_out_len > max_msg_size)
> +		return -ENOSPC;
> +
> +	hdcp_message = i915->display.hdcp.hdcp_message;
> +	header = hdcp_message->hdcp_cmd;
> +	addr = i915_ggtt_offset(hdcp_message->vma);
> +
> +	msg_size = msg_in_len + sizeof(*header);
> +	memset(header, 0, msg_size);
> +	get_random_bytes(&host_session_id, sizeof(u64));
> +	intel_gsc_uc_heci_cmd_emit_mtl_header(header,
> HECI_MEADDRESS_HDCP,
> +					      msg_size, host_session_id);
> +	memcpy(hdcp_message->hdcp_cmd + sizeof(*header), msg_in, msg_in_len);
> +
> +	/*
> +	 * Keep sending request in case the pending bit is set no need to add
> +	 * message handle as we are using same address hence loc. of header is
> +	 * same and it will contain the message handle. we will send the message
> +	 * 20 times each message 50 ms apart
> +	 */
> +	do {
> +		ret = intel_gsc_send_sync(i915, header, addr, msg_out_len);
> +
> +		/* Only try again if gsc says so */
> +		if (ret != -EAGAIN)
> +			break;
> +
> +		msleep(50);
> +
> +	} while (++tries < 20);
> +
> +	if (ret)
> +		goto err;
> +
> +	/* we use the same mem for the reply, so header is in the same loc */
> +	reply_size = header->message_size - sizeof(*header);
> +	if (reply_size > msg_out_len) {
> +		drm_warn(&i915->drm, "caller with insufficient HDCP reply size %u
> (%d)\n",
> +			 reply_size, (u32)msg_out_len);
> +		reply_size = msg_out_len;
> +	} else if (reply_size != msg_out_len) {
> +		drm_dbg_kms(&i915->drm, "caller unexpected HCDP reply size %u
> (%d)\n",
> +			    reply_size, (u32)msg_out_len);
> +	}
> +
> +	memcpy(msg_out, hdcp_message->hdcp_cmd + sizeof(*header),
> +msg_out_len);
> +
> +err:
> +	return ret;
> +}
> diff --git a/drivers/gpu/drm/i915/display/intel_hdcp_gsc.h
> b/drivers/gpu/drm/i915/display/intel_hdcp_gsc.h
> new file mode 100644
> index 000000000000..09ffd7ec02cd
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/display/intel_hdcp_gsc.h
> @@ -0,0 +1,23 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2023 Intel Corporation
> + */
> +
> +#ifndef __INTEL_HDCP_GSC_H__
> +#define __INTEL_HDCP_GSC_H__
> +
> +#include <linux/err.h>
> +#include <linux/types.h>
> +
> +struct drm_i915_private;
> +
> +struct intel_hdcp_gsc_message {
> +	struct i915_vma *vma;
> +	void *hdcp_cmd;
> +};
> +
> +ssize_t intel_hdcp_gsc_msg_send(struct drm_i915_private *i915, u8 *msg_in,
> +				size_t msg_in_len, u8 *msg_out,
> +				size_t msg_out_len);
> +
> +#endif /* __INTEL_HDCP_GCS_H__ */
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc_heci_cmd_submit.c
> b/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc_heci_cmd_submit.c
> index be2424af521d..ea0da06e2f39 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc_heci_cmd_submit.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc_heci_cmd_submit.c
> @@ -92,3 +92,18 @@ int intel_gsc_uc_heci_cmd_submit_packet(struct intel_gsc_uc
> *gsc, u64 addr_in,
> 
>  	return err;
>  }
> +
> +void intel_gsc_uc_heci_cmd_emit_mtl_header(struct intel_gsc_mtl_header
> *header,
> +					   u8 heci_client_id, u32 message_size,
> +					   u64 host_session_id)
> +{
> +	host_session_id &= ~HOST_SESSION_MASK;
> +	if (heci_client_id == HECI_MEADDRESS_PXP)
> +		host_session_id |= HOST_SESSION_PXP_SINGLE;
> +
> +	header->validity_marker = GSC_HECI_VALIDITY_MARKER;
> +	header->heci_client_id = heci_client_id;
> +	header->host_session_handle = host_session_id;
> +	header->header_version = MTL_GSC_HEADER_VERSION;
> +	header->message_size = message_size;
> +}
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc_heci_cmd_submit.h
> b/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc_heci_cmd_submit.h
> index cf610dfca7a5..3d56ae501991 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc_heci_cmd_submit.h
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_gsc_uc_heci_cmd_submit.h
> @@ -22,7 +22,17 @@ struct intel_gsc_mtl_header {
>  	u16 header_version;
>  #define MTL_GSC_HEADER_VERSION 1
> 
> +	/*
> +	 * FW allows host to decide host_session handle
> +	 * as it sees fit.
> +	 * For intertracebility reserving select bits(60-63)
> +	 * to differentiate caller-target subsystem
> +	 * 0000 - HDCP
> +	 * 0001 - PXP Single Session
> +	 */
>  	u64 host_session_handle;
> +#define HOST_SESSION_MASK	REG_GENMASK64(63, 60)
> +#define HOST_SESSION_PXP_SINGLE BIT_ULL(60)
>  	u64 gsc_message_handle;
> 
>  	u32 message_size; /* lower 20 bits only, upper 12 are reserved */ @@ -33,8
> +43,11 @@ struct intel_gsc_mtl_header {
>  	 * Bit 1: Session Cleanup;
>  	 * Bits 2-15: Flags
>  	 * Bits 16-31: Extension Size
> +	 * According to internal spec flags are either input or output
> +	 * we distinguish the flags using OUTFLAG or INFLAG
>  	 */
>  	u32 flags;
> +#define GSC_OUTFLAG_MSG_PENDING	1
> 
>  	u32 status;
>  } __packed;
> @@ -42,4 +55,7 @@ struct intel_gsc_mtl_header {  int
> intel_gsc_uc_heci_cmd_submit_packet(struct intel_gsc_uc *gsc,
>  					u64 addr_in, u32 size_in,
>  					u64 addr_out, u32 size_out);
> +void intel_gsc_uc_heci_cmd_emit_mtl_header(struct intel_gsc_mtl_header
> *header,
> +					   u8 heci_client_id, u32 message_size,
> +					   u64 host_session_id);
>  #endif
> --
> 2.25.1



More information about the Intel-gfx mailing list