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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Copyright (C) 2019 Intel Corporation.
- *
- * Authors:
- * Ramalingam C <ramalingam.c@intel.com>
- */
- #include <linux/device.h>
- #include <linux/err.h>
- #include <linux/gfp.h>
- #include <linux/export.h>
- #include <linux/slab.h>
- #include <linux/firmware.h>
- #include <drm/drm_hdcp.h>
- #include <drm/drm_sysfs.h>
- #include <drm/drm_print.h>
- #include <drm/drm_device.h>
- #include <drm/drm_property.h>
- #include <drm/drm_mode_object.h>
- #include <drm/drm_connector.h>
- #include "drm_internal.h"
- static inline void drm_hdcp_print_ksv(const u8 *ksv)
- {
- DRM_DEBUG("\t%#02x, %#02x, %#02x, %#02x, %#02x\n",
- ksv[0], ksv[1], ksv[2], ksv[3], ksv[4]);
- }
- static u32 drm_hdcp_get_revoked_ksv_count(const u8 *buf, u32 vrls_length)
- {
- u32 parsed_bytes = 0, ksv_count = 0, vrl_ksv_cnt, vrl_sz;
- while (parsed_bytes < vrls_length) {
- vrl_ksv_cnt = *buf;
- ksv_count += vrl_ksv_cnt;
- vrl_sz = (vrl_ksv_cnt * DRM_HDCP_KSV_LEN) + 1;
- buf += vrl_sz;
- parsed_bytes += vrl_sz;
- }
- /*
- * When vrls are not valid, ksvs are not considered.
- * Hence SRM will be discarded.
- */
- if (parsed_bytes != vrls_length)
- ksv_count = 0;
- return ksv_count;
- }
- static u32 drm_hdcp_get_revoked_ksvs(const u8 *buf, u8 **revoked_ksv_list,
- u32 vrls_length)
- {
- u32 vrl_ksv_cnt, vrl_ksv_sz, vrl_idx = 0;
- u32 parsed_bytes = 0, ksv_count = 0;
- do {
- vrl_ksv_cnt = *buf;
- vrl_ksv_sz = vrl_ksv_cnt * DRM_HDCP_KSV_LEN;
- buf++;
- DRM_DEBUG("vrl: %d, Revoked KSVs: %d\n", vrl_idx++,
- vrl_ksv_cnt);
- memcpy((*revoked_ksv_list) + (ksv_count * DRM_HDCP_KSV_LEN),
- buf, vrl_ksv_sz);
- ksv_count += vrl_ksv_cnt;
- buf += vrl_ksv_sz;
- parsed_bytes += (vrl_ksv_sz + 1);
- } while (parsed_bytes < vrls_length);
- return ksv_count;
- }
- static inline u32 get_vrl_length(const u8 *buf)
- {
- return drm_hdcp_be24_to_cpu(buf);
- }
- static int drm_hdcp_parse_hdcp1_srm(const u8 *buf, size_t count,
- u8 **revoked_ksv_list, u32 *revoked_ksv_cnt)
- {
- struct hdcp_srm_header *header;
- u32 vrl_length, ksv_count;
- if (count < (sizeof(struct hdcp_srm_header) +
- DRM_HDCP_1_4_VRL_LENGTH_SIZE + DRM_HDCP_1_4_DCP_SIG_SIZE)) {
- DRM_ERROR("Invalid blob length\n");
- return -EINVAL;
- }
- header = (struct hdcp_srm_header *)buf;
- DRM_DEBUG("SRM ID: 0x%x, SRM Ver: 0x%x, SRM Gen No: 0x%x\n",
- header->srm_id,
- be16_to_cpu(header->srm_version), header->srm_gen_no);
- WARN_ON(header->reserved);
- buf = buf + sizeof(*header);
- vrl_length = get_vrl_length(buf);
- if (count < (sizeof(struct hdcp_srm_header) + vrl_length) ||
- vrl_length < (DRM_HDCP_1_4_VRL_LENGTH_SIZE +
- DRM_HDCP_1_4_DCP_SIG_SIZE)) {
- DRM_ERROR("Invalid blob length or vrl length\n");
- return -EINVAL;
- }
- /* Length of the all vrls combined */
- vrl_length -= (DRM_HDCP_1_4_VRL_LENGTH_SIZE +
- DRM_HDCP_1_4_DCP_SIG_SIZE);
- if (!vrl_length) {
- DRM_ERROR("No vrl found\n");
- return -EINVAL;
- }
- buf += DRM_HDCP_1_4_VRL_LENGTH_SIZE;
- ksv_count = drm_hdcp_get_revoked_ksv_count(buf, vrl_length);
- if (!ksv_count) {
- DRM_DEBUG("Revoked KSV count is 0\n");
- return 0;
- }
- *revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, GFP_KERNEL);
- if (!*revoked_ksv_list) {
- DRM_ERROR("Out of Memory\n");
- return -ENOMEM;
- }
- if (drm_hdcp_get_revoked_ksvs(buf, revoked_ksv_list,
- vrl_length) != ksv_count) {
- *revoked_ksv_cnt = 0;
- kfree(*revoked_ksv_list);
- return -EINVAL;
- }
- *revoked_ksv_cnt = ksv_count;
- return 0;
- }
- static int drm_hdcp_parse_hdcp2_srm(const u8 *buf, size_t count,
- u8 **revoked_ksv_list, u32 *revoked_ksv_cnt)
- {
- struct hdcp_srm_header *header;
- u32 vrl_length, ksv_count, ksv_sz;
- if (count < (sizeof(struct hdcp_srm_header) +
- DRM_HDCP_2_VRL_LENGTH_SIZE + DRM_HDCP_2_DCP_SIG_SIZE)) {
- DRM_ERROR("Invalid blob length\n");
- return -EINVAL;
- }
- header = (struct hdcp_srm_header *)buf;
- DRM_DEBUG("SRM ID: 0x%x, SRM Ver: 0x%x, SRM Gen No: 0x%x\n",
- header->srm_id & DRM_HDCP_SRM_ID_MASK,
- be16_to_cpu(header->srm_version), header->srm_gen_no);
- if (header->reserved)
- return -EINVAL;
- buf = buf + sizeof(*header);
- vrl_length = get_vrl_length(buf);
- if (count < (sizeof(struct hdcp_srm_header) + vrl_length) ||
- vrl_length < (DRM_HDCP_2_VRL_LENGTH_SIZE +
- DRM_HDCP_2_DCP_SIG_SIZE)) {
- DRM_ERROR("Invalid blob length or vrl length\n");
- return -EINVAL;
- }
- /* Length of the all vrls combined */
- vrl_length -= (DRM_HDCP_2_VRL_LENGTH_SIZE +
- DRM_HDCP_2_DCP_SIG_SIZE);
- if (!vrl_length) {
- DRM_ERROR("No vrl found\n");
- return -EINVAL;
- }
- buf += DRM_HDCP_2_VRL_LENGTH_SIZE;
- ksv_count = (*buf << 2) | DRM_HDCP_2_KSV_COUNT_2_LSBITS(*(buf + 1));
- if (!ksv_count) {
- DRM_DEBUG("Revoked KSV count is 0\n");
- return 0;
- }
- *revoked_ksv_list = kcalloc(ksv_count, DRM_HDCP_KSV_LEN, GFP_KERNEL);
- if (!*revoked_ksv_list) {
- DRM_ERROR("Out of Memory\n");
- return -ENOMEM;
- }
- ksv_sz = ksv_count * DRM_HDCP_KSV_LEN;
- buf += DRM_HDCP_2_NO_OF_DEV_PLUS_RESERVED_SZ;
- DRM_DEBUG("Revoked KSVs: %d\n", ksv_count);
- memcpy(*revoked_ksv_list, buf, ksv_sz);
- *revoked_ksv_cnt = ksv_count;
- return 0;
- }
- static inline bool is_srm_version_hdcp1(const u8 *buf)
- {
- return *buf == (u8)(DRM_HDCP_1_4_SRM_ID << 4);
- }
- static inline bool is_srm_version_hdcp2(const u8 *buf)
- {
- return *buf == (u8)(DRM_HDCP_2_SRM_ID << 4 | DRM_HDCP_2_INDICATOR);
- }
- static int drm_hdcp_srm_update(const u8 *buf, size_t count,
- u8 **revoked_ksv_list, u32 *revoked_ksv_cnt)
- {
- if (count < sizeof(struct hdcp_srm_header))
- return -EINVAL;
- if (is_srm_version_hdcp1(buf))
- return drm_hdcp_parse_hdcp1_srm(buf, count, revoked_ksv_list,
- revoked_ksv_cnt);
- else if (is_srm_version_hdcp2(buf))
- return drm_hdcp_parse_hdcp2_srm(buf, count, revoked_ksv_list,
- revoked_ksv_cnt);
- else
- return -EINVAL;
- }
- static int drm_hdcp_request_srm(struct drm_device *drm_dev,
- u8 **revoked_ksv_list, u32 *revoked_ksv_cnt)
- {
- char fw_name[36] = "display_hdcp_srm.bin";
- const struct firmware *fw;
- int ret;
- ret = request_firmware_direct(&fw, (const char *)fw_name,
- drm_dev->dev);
- if (ret < 0) {
- *revoked_ksv_cnt = 0;
- *revoked_ksv_list = NULL;
- ret = 0;
- goto exit;
- }
- if (fw->size && fw->data)
- ret = drm_hdcp_srm_update(fw->data, fw->size, revoked_ksv_list,
- revoked_ksv_cnt);
- exit:
- release_firmware(fw);
- return ret;
- }
- /**
- * drm_hdcp_check_ksvs_revoked - Check the revoked status of the IDs
- *
- * @drm_dev: drm_device for which HDCP revocation check is requested
- * @ksvs: List of KSVs (HDCP receiver IDs)
- * @ksv_count: KSV count passed in through @ksvs
- *
- * This function reads the HDCP System renewability Message(SRM Table)
- * from userspace as a firmware and parses it for the revoked HDCP
- * KSVs(Receiver IDs) detected by DCP LLC. Once the revoked KSVs are known,
- * revoked state of the KSVs in the list passed in by display drivers are
- * decided and response is sent.
- *
- * SRM should be presented in the name of "display_hdcp_srm.bin".
- *
- * Format of the SRM table, that userspace needs to write into the binary file,
- * is defined at:
- * 1. Renewability chapter on 55th page of HDCP 1.4 specification
- * https://www.digital-cp.com/sites/default/files/specifications/HDCP%20Specification%20Rev1_4_Secure.pdf
- * 2. Renewability chapter on 63rd page of HDCP 2.2 specification
- * https://www.digital-cp.com/sites/default/files/specifications/HDCP%20on%20HDMI%20Specification%20Rev2_2_Final1.pdf
- *
- * Returns:
- * Count of the revoked KSVs or -ve error number incase of the failure.
- */
- int drm_hdcp_check_ksvs_revoked(struct drm_device *drm_dev, u8 *ksvs,
- u32 ksv_count)
- {
- u32 revoked_ksv_cnt = 0, i, j;
- u8 *revoked_ksv_list = NULL;
- int ret = 0;
- ret = drm_hdcp_request_srm(drm_dev, &revoked_ksv_list,
- &revoked_ksv_cnt);
- if (ret)
- return ret;
- /* revoked_ksv_cnt will be zero when above function failed */
- for (i = 0; i < revoked_ksv_cnt; i++)
- for (j = 0; j < ksv_count; j++)
- if (!memcmp(&ksvs[j * DRM_HDCP_KSV_LEN],
- &revoked_ksv_list[i * DRM_HDCP_KSV_LEN],
- DRM_HDCP_KSV_LEN)) {
- DRM_DEBUG("Revoked KSV is ");
- drm_hdcp_print_ksv(&ksvs[j * DRM_HDCP_KSV_LEN]);
- ret++;
- }
- kfree(revoked_ksv_list);
- return ret;
- }
- EXPORT_SYMBOL_GPL(drm_hdcp_check_ksvs_revoked);
- static struct drm_prop_enum_list drm_cp_enum_list[] = {
- { DRM_MODE_CONTENT_PROTECTION_UNDESIRED, "Undesired" },
- { DRM_MODE_CONTENT_PROTECTION_DESIRED, "Desired" },
- { DRM_MODE_CONTENT_PROTECTION_ENABLED, "Enabled" },
- };
- DRM_ENUM_NAME_FN(drm_get_content_protection_name, drm_cp_enum_list)
- static struct drm_prop_enum_list drm_hdcp_content_type_enum_list[] = {
- { DRM_MODE_HDCP_CONTENT_TYPE0, "HDCP Type0" },
- { DRM_MODE_HDCP_CONTENT_TYPE1, "HDCP Type1" },
- };
- DRM_ENUM_NAME_FN(drm_get_hdcp_content_type_name,
- drm_hdcp_content_type_enum_list)
- /**
- * drm_connector_attach_content_protection_property - attach content protection
- * property
- *
- * @connector: connector to attach CP property on.
- * @hdcp_content_type: is HDCP Content Type property needed for connector
- *
- * This is used to add support for content protection on select connectors.
- * Content Protection is intentionally vague to allow for different underlying
- * technologies, however it is most implemented by HDCP.
- *
- * When hdcp_content_type is true enum property called HDCP Content Type is
- * created (if it is not already) and attached to the connector.
- *
- * This property is used for sending the protected content's stream type
- * from userspace to kernel on selected connectors. Protected content provider
- * will decide their type of their content and declare the same to kernel.
- *
- * Content type will be used during the HDCP 2.2 authentication.
- * Content type will be set to &drm_connector_state.hdcp_content_type.
- *
- * The content protection will be set to &drm_connector_state.content_protection
- *
- * When kernel triggered content protection state change like DESIRED->ENABLED
- * and ENABLED->DESIRED, will use drm_hdcp_update_content_protection() to update
- * the content protection state of a connector.
- *
- * Returns:
- * Zero on success, negative errno on failure.
- */
- int drm_connector_attach_content_protection_property(
- struct drm_connector *connector, bool hdcp_content_type)
- {
- struct drm_device *dev = connector->dev;
- struct drm_property *prop =
- dev->mode_config.content_protection_property;
- if (!prop)
- prop = drm_property_create_enum(dev, 0, "Content Protection",
- drm_cp_enum_list,
- ARRAY_SIZE(drm_cp_enum_list));
- if (!prop)
- return -ENOMEM;
- drm_object_attach_property(&connector->base, prop,
- DRM_MODE_CONTENT_PROTECTION_UNDESIRED);
- dev->mode_config.content_protection_property = prop;
- if (!hdcp_content_type)
- return 0;
- prop = dev->mode_config.hdcp_content_type_property;
- if (!prop)
- prop = drm_property_create_enum(dev, 0, "HDCP Content Type",
- drm_hdcp_content_type_enum_list,
- ARRAY_SIZE(
- drm_hdcp_content_type_enum_list));
- if (!prop)
- return -ENOMEM;
- drm_object_attach_property(&connector->base, prop,
- DRM_MODE_HDCP_CONTENT_TYPE0);
- dev->mode_config.hdcp_content_type_property = prop;
- return 0;
- }
- EXPORT_SYMBOL(drm_connector_attach_content_protection_property);
- /**
- * drm_hdcp_update_content_protection - Updates the content protection state
- * of a connector
- *
- * @connector: drm_connector on which content protection state needs an update
- * @val: New state of the content protection property
- *
- * This function can be used by display drivers, to update the kernel triggered
- * content protection state changes of a drm_connector such as DESIRED->ENABLED
- * and ENABLED->DESIRED. No uevent for DESIRED->UNDESIRED or ENABLED->UNDESIRED,
- * as userspace is triggering such state change and kernel performs it without
- * fail.This function update the new state of the property into the connector's
- * state and generate an uevent to notify the userspace.
- */
- void drm_hdcp_update_content_protection(struct drm_connector *connector,
- u64 val)
- {
- struct drm_device *dev = connector->dev;
- struct drm_connector_state *state = connector->state;
- WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
- if (state->content_protection == val)
- return;
- state->content_protection = val;
- drm_sysfs_connector_status_event(connector,
- dev->mode_config.content_protection_property);
- }
- EXPORT_SYMBOL(drm_hdcp_update_content_protection);
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